Enterobacters

Zh Mikrobiol Epidemiol Immunobiol, 1999 May-Jun, (3), 3 - 6
{The seroresistance of enterobacteria isolated from different sources}; Gritsenko VA et al.; 395 representatives of the family Enterobacteriaceae, isolated from household and drinking water, from healthy and sick persons, were used as an example to demonstrate that their seroresistance was greatly connected with the type of the source from which these bacteria had been isolated . Experiments showed the phenotypic conversion of Escherichia coli towards an increase in their seroresistance on contact with human blood serum . The study revealed the pleiotropic effect produced by the action of serum on a number of other properties, responsible for survival in a macroorganism (anticomplement and antilysozyme activities, adhesive capacity and hydrophobic properties of the outer surface).

Antibiot Khimioter, 2000, 45(4), 28 - 9
{Enterobacterial sensitivity to beta-lactam antibiotics}; Chernen'kaia TV; The susceptibility to betalactams of 868 enteric bacteria isolated from the patients at the hospital was studied . The isolated pathogens included: E . coli (549), Klebsiella sp . (195), Serratia sp . (124) . Ampicillin and cefazoline demonstrated the lowest activity . Cefotaxime, ceftazidime and imipenem were active against 90 per cent of isolates . Among E . coli isolates the susceptibility to the above mentioned drugs was the following: 95.1, 96.9, 99.3 per cent, among Klebsiella sp.--89.7, 88.7, 97.9 per cent, among Proteus sp.--89.5, 90.3, 91.9 per cent respectively . Thus cefotaxime may be used in antibacterial empiric therapy if Pseudomonas aeruginosa infection is excluded.

Am J Vet Res, 2000 Jun, 61(6), 699 - 705
Use of repetitive sequence-based polymerase chain reaction for molecular epidemiologic analysis of Streptococcus equi subspecies equi; Al-Ghamdi GM et al.; OBJECTIVE: To determine whether repetitive sequence-based polymerase chain reaction (rep-PCR) could be used to differentiate Streptococcus equi isolates, to examine S equi isolates from throughout the world, and to determine whether a horse had > 1 subtype of S equi during an outbreak of disease . SAMPLE POPULATION: An initial group of 32 S equi isolates, 63 S equi isolates from various geographic areas, and 17 S equi isolates obtained during outbreaks of disease . PROCEDURE: An aliquot of S equi genomic DNA was amplified, using enterobacterial repetitive intergenic consensus primers . Gel electrophoresis was performed on 1.5% agarose gels, and a computed-assisted program was used to compare rep-PCR results . RESULTS: Use of these primers to analyze 100 ng of S equi genomic DNA resulted in patterns of 6 to 14 bands . The 32 initial isolates were separated into 7 rep-PCR subtypes . There were 30 rep-PCR subtypes found among 29 S equi isolates obtained from Minnesota, Michigan, Canada, and Australia and 34 S equi isolates obtained from Kentucky and other sources . Furthermore, the same clone was identified in several horses during an outbreak of disease . Infected horses on the same farm all had a single clone of S equi . CONCLUSION AND CLINICAL RELEVANCE: Analysis of these results suggests that rep-PCR is useful for delineating S equi into rep-PCR subtypes . Results revealed that isolates with the same geographic source or similar date of collection did not always have the same rep-PCR subtype . A single clone of S equi usually predominated during an outbreak of disease.

Helicobacter, 2000 Jun, 5(2), 69 - 78
Different Helicobacter pylori strains colonize the antral and duodenal mucosa of duodenal ulcer patients; Thoreson AC et al.; BACKGROUND: We have investigated the possibility that the same patients may be colonized by Helicobacter pylori strains of different genotypes or phenotypes in the antrum as compared to in the duodenum . The strains were typed for DNA fingerprints, different lipopolysaccharides (LPS), and Lewis antigen expression on the O-side chains of LPS . MATERIALS AND METHODS: Polymerase chain reaction (PCR) amplifications using primer sequences (i.e., the Enterobacterial Repetitive Intergenic Consensus {ERIC}) and randomly amplified polymorphic DNA (RAPD) elements were performed to asses chromosomal DNA diversity between H . pylori strains . The expression of different LPS types and Lewis antigens in the various H . pylori isolates were determined by whole bacterial enzyme-linked immunosorbent assays using monoclonal antibodies . RESULTS: Duodenal ulcer patients had different H . pylori genotypes in the duodenum as compared to in the antrum as shown by ERIC-PCR (44%) and by RAPD-PCR (75%) . Different DNA patterns were found among the strains that were isolated from various regions of the duodenum in 4 of 16 patients (25%) as shown by ERIC-PCR and in 8 of 16 patients (50%) as shown by RAPD-PCR . Sixty-three percent of the duodenal ulcer patients had H . pylori strains with a different Lewis antigen phenotype in the duodenum as compared to in the antrum, and 3 of 16 patients (19%) had strains with different Lewis antigens expressed by strains from different duodenal biopsies from the same patient . CONCLUSION: The results suggest that a mixed population of different H . pylori strains with marked variation, both genotypically and phenotypically, colonize the same patient.

Eur J Biochem, 2000 Jun, 267(12), 3672 - 84
Analysis of the domain structure and the DNA binding site of the transcriptional activator FhlA; Leonhartsberger S et al.; FhlA is the transcriptional activator of the genes coding for the formate hydrogen lyase system in Escherichia coli . It is activated by the binding of formate and induces transcription by sigma54 RNA polymerase after binding to specific upstream activating sequences (UAS) . Sequence comparison had shown that FhlA exhibits a structure composed of three domains, which is typical for sigma54-dependent regulators . By analyzing the N-terminal domain of FhlA of E . coli (amino acids 1-378; FhlA-N) and the rest of the protein (amino acids 379-693; FhlA-C) as separate proteins in vivo and in vitro the functions of the different domains of FhlA were elucidated . The FhlA-C domain is active in ATP hydrolysis and activation of transcription and its activity is neither influenced by the presence of formate nor of the antiactivator HycA . However, it is stimulated in the presence of the FhlA-specific UAS, indicating that this region of FhlA is responsible for DNA binding . FhlA-N is not active itself but able to reduce the activity of full-length FhlA in trans, probably by formation of nonfunctional heterooligomers . The DNA binding site of FhlA was analyzed by hydroxyradical footprinting . Each UAS consists of two binding sites of 16 bp separated by a spacer region . A consensus sequence could be deduced and a model is presented and supported by in vivo data in which a FhlA tetramer binds to the UAS on one side of the DNA helix . Performing an extensive screening we could show that the FhlA regulatory system is conserved in different species of the family Enterobacteriaceae . The analysis of orthologs of FhlA revealed that they are able to functionally replace the E . coli enzyme.

J Extra Corpor Technol, 1999 Sep, 31(3), 125 - 9
Investigations into the sterility of manually assembled extracorporeal circuits with vented reservoirs; Searles B et al.; This study was designed to investigate the ability of an extracorporeal circuit (ECC) with a vented hard shell reservoir to remain sterile for a period of 72 h under dry conditions . The study was conducted in three phases . In Phase One: Two previously published methods for detecting contamination of the ECC were compared . A group of positive controls was collected by contaminating identical circuits with a known level of Enterobacter cloacae (ATTC: 13047) before initiating a regimen of "sample-dilute-sample" culturing . Negative controls for this phase were conducted by randomly sampling 1 L per manufacturer's lot of lactated ringers with each detection method . Culture results suggest that large volume filtration, but not small aliquot sampling, is sensitive to extremely low levels of contamination . No growth was detected in any negative control samples . In Phase Two: 19 ECC consisting of a membrane oxygenator, vented hardshell reservoir, arterial filter, and PVC tubing were removed from their sterile packages, assembled, and left unprotected in the moderate traffic environment of a research laboratory . The circuits were then primed with Lactated Ringer's solution . The prime solution was sampled for aerobic contamination by large volume filtration . None of the 19 samples detected contamination . In Phase Three: 43 ECC identical to the Phase Two circuits were assembled and left unprotected in the substerile pump room . The circuits were then primed, circulated, and cultured as in Phase Two . One of the 43 samples was discarded because of a recognized break in aseptic technique during sample collection . None of the remaining samples detected contamination . Mathematical calculations of binomial probabilities suggest that the chance of an open ECC developing a detectable level of contamination within 72 h of its dry assembly is insignificant.

Int J Syst Evol Microbiol, 2000 May, 50 Pt 3, 1087 - 93
Rapid identification of Staphylococcus epidermidis; Wieser M et al.; During the collection of airborne bacteria in a museum in England some bacterial strains were isolated which due to their fatty acid profiles were clearly identified as members of the genus Staphylococcus . As fatty acid compositions of coagulase-negative staphylococci are very similar, differing only in quantities but not in qualities, further identification at the species level without a fatty acid database was not achieved . Investigation of the isolates using the Staph ID 32 API system resulted in an identification of the isolates as Staphylococcus epidermidis (probabilities of 79.7-95.5%) . For further genotypic characterization of these isolates, some Staphylococcus epidermidis strains from different sources and the type strains of Staphylococcus aureus, Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus gallinarum, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus warneri and Staphylococcus xylosus were subjected to repetitive-sequence PCR, including enterobacterial repetitive intergenic consensus (ERIC) PCR, BOX-PCR and repetitive extragenic palindromic unit sequence (REP) PCR . ERIC- and BOX-PCR yielded a species-specific banding pattern for all Staphylococcus epidermidis strains . Furthermore, all staphylococcal reference strains investigated exhibited distinct banding patterns, clearly distinguishable from that of Staphylococcus epidermidis . No species-specific banding patterns could be observed after REP-PCR . As species identification of coagulase-negative staphylococci by fatty acid analyses and biochemical tests is known to be difficult ERIC- and BOX-PCR seem to be excellent tools for the identification of Staphylococcus epidermidis isolates.

Int J Syst Evol Microbiol, 2000 May, 50 Pt 3, 1043 - 53
Characterization of Nodularia strains, cyanobacteria from brackish waters, by genotypic and phenotypic methods; Lehtimaki J et al.; An investigation was undertaken of the genetic diversity of Nodularia strains from the Baltic Sea and from Australian waters, together with the proposed type strain of Nodularia spumigena . The Nodularia strains were characterized by using a polyphasic approach, including RFLP of PCR-amplified 16S rRNA genes, 16S rRNA gene sequencing, Southern blotting of total DNA, repetitive extragenic palindromic- and enterobacterial repetitive intergenic consensus-PCR, ribotyping and phenotypic tests . With genotypic methods, the Nodularia strains were grouped into two clusters . The genetic groupings were supported by one phenotypic property: the ability to produce nodularin . In contrast, the cell sizes of the strains were not different in the two genetic clusters . 16S rRNA gene sequences indicated that all the Nodularia strains were closely related, despite their different origins . According to this study, two genotypes of Nodularia exist in the Baltic Sea . On the basis of the taxonomic definitions of Komarek et al . (Algol Stud 68, 1-25, 1993), the non-toxic type without gas vesicles fits the description of Nodularia sphaerocarpa, whereas the toxic type with gas vesicles resembles the species N . spumigena and Nodularia baltica.

Proteins, 2000 Aug 1, 40(2), 290 - 8
Comparative X-ray analysis of the un-liganded fosfomycin-target murA; Eschenburg S et al.; MurA, an essential enzyme for the synthesis of the bacterial cell wall, follows an induced-fit mechanism . Upon substrate binding, the active site forms in the interdomain cleft, involving movements of the two domains of the protein and a reorientation of the loop Pro112-Pro121 . We compare two structures of un-liganded MurA from Enterobacter cloacae: a new orthorhombic form, solved to 1.80 A resolution, and a monoclinic form, redetermined to 1.55 A resolution . In the monoclinic form, the loop Pro112-Pro121 stretches into solvent, while in the new form it adopts a winded conformation, thereby reducing solvent accessibility of the critical residue Cys115 . In the interdomain cleft a network of 27 common water molecules has been identified, which partially shields negative charges in the cleft and stabilizes the orientation of catalytically crucial residues . This could support substrate binding and ease domain movements . Near the hinge region an isoaspartyl residue has been recognized, which is the product of post-translational modification of the genetically encoded Asn67-Gly68 . The homogeneous population with L-isoaspartate in both structures suggests that the modification in Enterobacter cloacae MurA is not a mere aging defect but rather the result of a specific in vivo process .

Am J Infect Control, 2000 Jun, 28(3), 258 - 61
Enterobacter cloacae sepsis outbreak in a newborn unit caused by contaminated total parenteral nutrition solution; Tresoldi AT et al.; OBJECTIVE: The study aimed to investigate an outbreak caused by Enterobacter cloacae in a neonate intensive care unit . DESIGN: A descriptive study of an outbreak of sepsis in high-risk neonates was used . SETTING: The study was set in a tertiary care university teaching hospital . PATIENTS: The patients were 11 neonates infected with Enterobacter cloacae whose symptoms and signs of sepsis developed during a 16-hour period . All but one neonate received parenteral nutrition . Isolates from blood cultures, in-use parenteral nutrition solutions, and control aliquots of parenteral nutrition solution were typed by pulsed-field gel electrophoresis . RESULTS: Enterobacter cloacae was found in the refrigerated aliquots of parenteral nutrition solution, in blood cultures from infected newborns, and from in-use parenteral nutrition solutions . All these strains of Enterobacter cloacae had the same antibiotic susceptibility pattern and the same genomic DNA profile . The strain isolated from the one patient who did not receive parenteral nutrition presented a different susceptibility profile and genotype . CONCLUSION: The source of the nosocomial sepsis was the parenteral nutrition solution in 10 neonates . This contamination apparently occurred during preparation of the parenteral solution.

J Antimicrob Chemother, 2000 Jun, 45(6), 895 - 8
Antimicrobial resistance in Enterobacteriaceae in Brooklyn, NY: epidemiology and relation to antibiotic usage patterns; Saurina G et al.; In November 1997, all Enterobacteriaceae isolated at 15 hospitals in Brooklyn were collected . Extended-spectrum beta-lactamases (ESBLs) were present in 44% of 409 Klebsiella pneumoniae isolates . Six isolates had reduced susceptibility to carbapenems, including two that were not susceptible to any of the antibiotics tested . Pulsed field gel electrophoresis revealed a commonality of resistant isolates within and between hospitals . The occurrence of ESBLcontaining isolates was associated with cephalosporin usage (P = 0.055) . ESBLs were present in 4.7% of Escherichia coli and 9.5% of Proteus mirabilis isolates . It is concluded that ESBL-producing Enterobacteriaceae are endemic in Brooklyn, are spread between hospitals, and may be associated with cephalosporin usage.

J Antimicrob Chemother, 2000 Jun, 45(6), 881 - 5
Detection of extended-spectrum beta-lactamases in members of the family enterobacteriaceae: comparison of the MAST DD test, the double disc and the Etest ESBL; M'Zali FH et al.; A technically simple method-the MAST double disc (MDD) test-for the detection of extended-spectrum beta-lactamase (ESBL) production by bacteria is described . A wide range of ESBL, non-ESBL and Class 1 beta-lactamase-producing isolates was examined . The MDD test, which uses discs containing ceftazidime and a complementary disc containing ceftazidime and clavulanate and a second pair containing cefotaxime and cefotaxime and clavulanate was compared with the standard double disc diffusion test and an Etest method . Both the Etest and the MDD correctly identified 93% of ESBL producers . The MDD is an inexpensive alternative to current methods for the detection of ESBL production.

N Z Med J, 2000 Mar 24, 113(1106), 96 - 8
Nosocomial blood stream infection in Auckland Healthcare hospitals; Nicholls TM et al.; AIM: To report the epidemiology of nosocomial bloodstream infections in Auckland Healthcare Hospitals . METHODS: From January 1995 to December 1997 every positive blood culture result was followed up by an infection control nurse who recorded relevant clinical, laboratory and treatment information on a data collection sheet . The clinical significance of each isolate was determined and the most likely source recorded . RESULTS: During the three year study period, there were 1,046 nosocomial blood stream infections yielding 1,147 isolates . The most common isolates/groups were: coagulase negative staphylococci 19%, S . aureus 18%, E . coli 12%, streptococci 10%, other Enterobacteriaceae 10%, Enterobacter spp . 7%, Pseudomonas spp . 5%, anaerobes 2%, and yeasts 4% . The most common sources were: intravascular lines 40%, urinary tract 8%, skin/soft tissue 8%, gastrointestinal 7%, and unknown 25% . The overall results were strongly influenced by the neonatal intensive care unit at National Women's Hospital where 58% of blood stream infections had intravascular-lines as the source and 53% of the isolates were coagulase negative staphylococci . The overall blood stream infection rate was approximately 6/1,000 admissions . Rates per 1,000 inpatient days for haematology, intensive care, oncology, neonatal and all other patients were 13, 11, 3, 3 and 1 respectively . CONCLUSIONS: Surveillance data that are clinically relevant are useful in identifying areas where infection prevention strategies can be implemented . Because of the importance of lines as a source of nosocomial blood stream infections all aspects of line care are being reviewed with the aim of reducing these devices as a source of blood stream infection.

J Clin Microbiol, 2000 Jun, 38(6), 2204 - 9
Evaluation of IS200-PCR and comparison with other molecular markers To trace Salmonella enterica subsp . enterica serotype typhimurium bovine isolates from farm to meat; Millemann Y et al.; A procedure that uses an original molecular marker (IS200-PCR) and that is based on the amplification of DNA with outward-facing primers complementary to each end of IS200 has been evaluated with a collection of 85 Salmonella enterica subsp . enterica serotype Typhimurium isolates . These strains were isolated from a group of 10 cows at different stages: during transportation between the farm and the slaughterhouse, on the slaughter line, from the environment, and from the final product (ground beef) . The 85 isolates were characterized by their antibiotic resistance patterns and were compared by IS200-PCR and by use of four other genotypic markers . Those markers included restriction profiles for 16S and 23S rRNA (ribotypes) and amplification profiles obtained by different approaches: random amplified polymorphic DNA analysis, enterobacterial repetitive intergenic consensus PCR, and PCR ribotyping . The results of the IS200-PCR were in accordance with those of other molecular typing methods for this collection of isolates . Five different genotypes were found, which made it possible to refine the hypotheses on transmission obtained from phenotypic results . The genotyping results indicated the massive contamination of the whole group of animals and of the environment by one clonal strain originally recovered from one cow that excreted the strain . On the other hand, a few animals and their environment appeared to be simultaneously contaminated with genetically different strains.

J Hosp Infect, 2000 May, 45(1), 35 - 41
Molecular investigation of Stenotrophomonas maltophilia isolates exhibiting rapid emergence of ticarcillin-clavulanate resistance; Barbier-Frebour N et al.; The prevalence of Stenotrophomonas maltophilia resistance to ticarcillin-clavulanate has dramatically increased in our hospital over the past few years . Sixty-six clinical isolates, collected from 61 patients, were tested for antibiotic susceptibility and genotyped by two different enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) systems . Although two small outbreaks were identified in the medical intensive care unit, the remaining 58 strains generated 48 different PCR patterns . The rapid emergence of resistance in S . maltophilia occured in absence of an epidemic and was probably influenced by increasing-b-lactam use in our hospital .

J Hosp Infect, 2000 May, 45(1), 19 - 28
An evaluation of hospital cleaning regimes and standards; Griffith CJ et al.; A four-part study assessing cleanliness in up to 113 environmental surfaces in an operating theatre and a hospital ward is reported . Surfaces were assessed visually, using microbiological methods and ATP bioluminescence . Results from a preliminary random survey indicated variability in cleanliness . These results were then used to select sites for monitoring before and after routine cleaning, over a 14-day period . Using published microbiological and ATP specifications 70 and 76% of these sites were unacceptable after cleaning . Visual assessment was a poor indicator of cleaning efficacy with only 18% considered unacceptable . Sites most likely to fail in the ward were in the toilet and kitchen, areas which are frequently implicated in the spread of infectious intestinal disease . Operating theatre sites had lower ATP results but 61% of sites would be considered unacceptable . There was no significant difference in general microbiological or ATP results overall before and after routine cleaning . Although some important hand contact sites showed no significant difference, overall there was a significant decrease in staphylococcal and enterobacteria counts in the ward but not in the operating theatre after cleaning . The routine cleaning programmes used did not include a biocide and cleaning using a hypochlorite based sanitizer gave much lower values . The results are discussed in relation to infection control, cleaning audits and cleaning schedules: an integrated cleaning monitoring programme using ATP bioluminescence in conjunction with visual and microbiological assessments is recommended .

Indian J Pediatr, 1996 Jul-Aug, 63(4), 517 - 21
Intravenous immunoglobulin for prophylaxis of nosocomial sepsis; Atici A et al.; A total of 76 premature newborn infants with gestational age of 34 weeks or less were enrolled in a randomized controlled study to determine whether intravenously administrated immunoglobulin (IVIG) is able to prevent nosocomial sepsis . Forty infants were given 0.5 g/kg IVIG on the first day of life and 36 infants with similar gestational age and birth weight were selected as controls and did not receive IVIG . The frequency of proven sepsis, with a positive blood and/or cerebrospinal fluid culture, was significantly lower in infants who received IVIG as compared to controls (42.5 vs 80.0%) (p < 0.01) . The mortality rate attributable to infection was not different in IVIG recipients and in controls (41 vs 48%) (p > 0.05) . The overall mortality rates in the two groups were not different either (35.0 vs 44.4%) (p > 0.05) . The majority of micro-organisms isolated from the blood culture of the patients were gram negative microorganisms (Klebsiella, Enterobacter) . IVIG therapy was believed to be effective for prophylaxis of nosocomial infection, but such therapy was not able to reduce overall mortality rate or mortality rate due to systemic infection in prematurely born infants in our intensive care unit where the causative pathogens are usually gram negative microorganisms.

Appl Environ Microbiol, 2000 Jun, 66(6), 2536 - 40
Role of volatile fatty acids in development of the cecal microflora in broiler chickens during growth; van Der Wielen PW et al.; It is known that volatile fatty acids can inhibit growth of species of the family Enterobacteriaceae in vitro . However, whether these volatile fatty acids affect bacterial populations in the ceca of chickens is unknown . Therefore, a study was conducted to investigate if changes in volatile fatty acids in ceca of broiler chickens during growth affect bacterial populations . Results showed that members of the Enterobacteriaceae and enterococci are present in large numbers in 3-day-old broilers and start to decrease when broilers grow older . Lactobacilli are present in large numbers as well in 3-day-old broilers, but they remain stable during the growth of broilers . Acetate, butyrate, and propionate increase from undetectable levels in 1-day-old broilers to high concentrations in 15-day-old broilers, after which they stabilize . Significant negative correlations could be calculated between numbers of Enterobacteriaceae and concentrations of undissociated acetate, propionate, and butyrate . Furthermore, pure cultures of Enterobacteriaceae isolated from the ceca were grown in the presence of volatile fatty acids . Growth rates and maximal optical density decreased when these strains grew in the presence of increasing volatile fatty acid concentrations . It is concluded that volatile fatty acids are responsible for the reduction in numbers of Enterobacteriaceae in the ceca of broiler chickens during growth.

Appl Environ Microbiol, 2000 Jun, 66(6), 2318 - 24
Molecular cloning, sequencing, and expression of omp-40, the gene coding for the major outer membrane protein from the acidophilic bacterium Thiobacillus ferrooxidans; Guiliani N et al.; Thiobacillus ferrooxidans is one of the chemolithoautotrophic bacteria important in industrial biomining operations . Some of the surface components of this microorganism are probably involved in adaptation to their acidic environment and in bacterium-mineral interactions . We have isolated and characterized omp40, the gene coding for the major outer membrane protein from T . ferrooxidans . The deduced amino acid sequence of the Omp40 protein has 382 amino acids and a calculated molecular weight of 40,095.7 . Omp40 forms an oligomeric structure of about 120 kDa that dissociates into the monomer (40 kDa) by heating in the presence of sodium dodecyl sulfate . The degree of identity of Omp40 amino acid sequence to porins from enterobacteria was only 22% . Nevertheless, multiple alignments of this sequence with those from several OmpC porins showed several important features conserved in the T . ferrooxidans surface protein, such as the approximate locations of 16 transmembrane beta strands, eight loops, including a large external L3 loop, and eight turns which allowed us to propose a putative 16-stranded beta-barrel porin structure for the protein . These results together with the previously known capacity of Omp40 to form ion channels in planar lipid bilayers strongly support its role as a porin in this chemolithoautotrophic acidophilic microorganism . Some characteristics of the Omp40 protein, such as the presence of a putative L3 loop with an estimated isoelectric point of 7.21 allow us to speculate that this can be the result of an adaptation of the acidophilic T . ferrooxidans to prevent free movement of protons across its outer membrane.

Biometals, 2000 Mar, 13(1), 65 - 72
A gene of the major facilitator superfamily encodes a transporter for enterobactin (Enb1p) in Saccharomyces cerevisiae; Heymann P et al.; While in fungi iron transport via hydroxamate siderophores has been amply proven, iron transport via enterobactin is largely unknown . Enterobactin is a catecholate-type siderophore produced by several enterobacterial genera grown in severe iron deprivation . By using the KanMX disruption module in vector pUG6 in a fet3delta background of Saccharomyces cerevisiae we were able to disrupt the gene YOL158c Sce of the major facilitator super family (MFS) which has been previously described as a gene encoding a membrane transporter of unknown function . Contrary to the parental strain, the disruptant was unable to utilize ferric enterobactin in growth promotion tests and in transport assays using 55Fe-enterobactin . All other siderophore transport properties remained unaffected . The results are evidence that in S . cerevisiae the YOL158c Sce gene of the major facilitator super family, now designated ENB1, encodes a transporter protein (Enb1p), which specifically recognizes and transports enterobactin.

Infect Dis Clin North Am, 2000 Jun, 14(2), 435 - 47, ix
Cephalosporins, carbapenems, and monobactams; Asbel LE et al.; Nonpenicillin beta-lactams exhibit a variable spectrum of antimicrobial activity, have a wide range of clinical uses and a favorable safety profile . Cefepime's twice-daily dosage and increased activity against Enterobacteriaceae may offer some advantages over older cephalosporins . The carbapenems offer a broad antimicrobial spectrum, and meropenem has an improved safety profile compared with imipenem . Aztreonam is a useful alternative for patients with aerobic gram-negative infections who are allergic to penicillin . The emergence of resistant organisms, however, is an increasing problem with the frequent use of these antibiotics.

Curr Microbiol, 2000 Jun, 40(6), 367 - 71
Transformation of internal extracellular bacteria isolated from Rhagoletis completa cresson gut with enhanced green fluorescent protein; Peloquin JJ et al.; We discovered Zeocintrade mark is an effective antibiotic against Enterobacter agglomerans and Klebsiella pneumoniae strains isolated from the walnut husk fly (Rhagoletis completa Cresson: Family Tephritidae) and that bleomycin resistance can be used as a selective marker in transforming plasmids . We transformed Ent . agglomerans and K . pneumoniae strains originally isolated from their close association with R . completa gut to produce enhanced green fluorescent protein, a variant of green fluorescent protein in the first demonstration of genetic transformation of internal extracellular bacteria isolated from a tephritid pest . We report methods for plasmid-mediated transformation of these bacteria, the expression of fluorescent marker protein from the transforming plasmids, and the stability of the transforming plasmid in the bacteria . We also discuss applications of this technology in the study of pest biology and control implementation.

Scand J Infect Dis, 2000, 32(2), 189 - 96
Influence of breastmilk on the development of resistance to intestinal colonization in infants born at the Atma Jaya Hospital, Jakarta; Bonang G et al.; A study of intestinal colonization resistance (CR) in breastfed versus formula-fed newborns at 4 intervals after birth in Jakarta, Indonesia, is described . To measure the intestinal CR for gram-negative enterobacilli, mean values of Enterobacteriaceae concentrations and mean numbers of Enterobacteriaceae biotypes were determined . The CR values found in this study show, that in all 4 sampling periods, at < 1, 2, 4 and 6 months, the mean concentration of Enterobacteriaceae was somewhat lower in the breastfed group than in the formula-fed group (only significant at 6 months) . This means that the intestinal CR of the breastfed group may have been slightly higher than that in the formula-fed group . In both study groups, the CR was lower in the second and fourth month than soon after birth and at 6 months . For epidemiological reasons, comparison was performed of the Enterobacteriaceae biotypes found in samples from mother and child . The data show that, in the first sampling period, regardless of the theoretical possibility of a 'more intense (skin) contact' during breastfeeding (which might promote transfer of also microorganisms), the breastfed infants had a significantly lower percentage of identical Enterobacteriaceae biotypes than did the formula-fed group . This could possibly be ascribed to a higher CR in the breastfed group . Determination of the concentration of Enterococcus species was found applicable to reproducibly measure the CR in the newborns at 6 months and in the mother-group.

J Food Prot, 2000 May, 63(5), 633 - 7
Effect of electron beam irradiation on color and microbial bioburden of red paprika; Nieto-Sandoval JM et al.; The effect of irradiation with electron beams on the microbiological quality and color properties of red paprika was examined . The irradiation doses ranged from 0 to 12.5 kGy . The counts performed were total mesophilic aerobic microorganisms, Enterobacteriaceae, coliforms, sulfite-reducing clostridia, molds, and yeasts . It was concluded that molds, yeasts, and sulfite-reducing clostridia were the most resistant species, although a 10-kGy dose of irradiation leads to optimum sanitation . Extractable color and apparent color were analyzed to appraise the incidence of the irradiation treatments in the color properties of red paprika . Extractable color was determined according to the American Spice Trade Association method, and apparent color was analyzed by reflectance using the CIELab color space . Data showed no significant differences between the color properties of irradiated and nonirradiated samples . Irradiation was a suitable procedure to minimize the bioburden of red paprika with small modifications of its color properties.

Antimicrob Agents Chemother, 2000 Jun, 44(6), 1470 - 8
Biochemical-genetic characterization and regulation of expression of an ACC-1-like chromosome-borne cephalosporinase from Hafnia alvei; Girlich D et al.; A naturally occurring AmpC beta-lactamase (cephalosporinase) gene was cloned from the Hafnia alvei 1 clinical isolate and expressed in Escherichia coli . The deduced AmpC beta-lactamase (ACC-2) had a pI of 8 and a relative molecular mass of 37 kDa and showed 50 and 47% amino acid identity with the chromosome-encoded AmpCs from Serratia marcescens and Providentia stuartii, respectively . It had 94% amino acid identity with the recently described plasmid-borne cephalosporinase ACC-1 from Klebsiella pneumoniae, suggesting the chromosomal origin of ACC-1 . The hydrolysis constants (k(cat) and K(m)) showed that ACC-2 was a peculiar cephalosporinase, since it significantly hydrolyzed cefpirome . Once its gene was cloned and expressed in E . coli (pDEL-1), ACC-2 conferred resistance to ceftazidime and cefotaxime but also an uncommon reduced susceptibility to cefpirome . A divergently transcribed ampR gene with an overlapping promoter compared with ampC (bla(ACC-2)) was identified in H . alvei 1, encoding an AmpR protein that shared 64% amino acid identity with the closest AmpR protein from P . stuartii . beta-Lactamase induction experiments showed that the ampC gene was repressed in the absence of ampR and was activated when cefoxitin or imipenem was added as an inducer . From H . alvei 1 cultures that expressed an inducible-cephalosporinase phenotype, several ceftazidime- and cefpirome-cross-resistant H . alvei 1 mutants were obtained upon selection on cefpirome- or ceftazidime-containing plates, and H . alvei 1 DER, a ceftazidime-resistant mutant, stably overproduced cephalosporinase . Transformation of H . alvei 1 DER or E . coli JRG582 (ampDE mutant) harboring ampC and ampR from H . alvei 1 with a recombinant plasmid containing ampD from E . coli resulted in a decrease in the MIC of beta-lactam and recovery of an inducible phenotype for H . alvei 1 DER . Thus, AmpR and AmpD proteins may regulate biosynthesis of the H . alvei cephalosporinase similarly to other enterobacterial cephalosporinases.

Int Surg, 2000 Jan-Mar, 85(1), 77 - 81
Fournier's gangrene in Nigeria: a review of 21 consecutive patients; Eke N et al.; A review of 21 consecutive cases of Fournier's gangrene seen at the University of Port Harcourt Teaching Hospital (UPTH) in the period 1994-1998 is presented . All the patients were males with an average age of 43.4 years . Most of the patients had a predisposing factor . There was a low incidence of pre-existing medical conditions . The commonest organisms isolated were of the enterobacteria group . All the patients were treated with antibiotics, surgical debridement and frequent wound dressings with hypertonic saline, hydrogen peroxide and Eusol . In 71.4% of the cases, the wounds healed by secondary intention . The mortality was 9.5% . The deaths occurred in the older age group . We recommend surgical debridement of necrotic tissues as they present and suggest that the surgical procedures be minimal as scrotal wounds heal satisfactorily.

J Biotechnol, 2000 Apr 14, 79(1), 63 - 72
Use of a plasmid of a yersinia enterocolitica biogroup 1A strain for the construction of cloning vectors; Strauch E et al.; A plasmid with a size of 2,682 base pairs isolated from the Yersinia enterocolitica biogroup 1A strain # 29807 was characterized in respect to its suitability as a basic replicon for cloning vectors . The copy number of the plasmid was determined to be approximately 14 copies per cell and it was shown to be compatible with vectors with an origin of replication derived from ColE1 and p115A . The replication region of the plasmid encodes a primer RNAI and countertranscript RNAII . Two vectors, pIV1 and pIV2, containing a kanamycin resistance gene and the lacZalpha fragment with the multiple cloning site of pBluescriptSK + were constructed . A mobilizable derivative was successfully introduced into different bacteria belonging to the family Enterobacteriacea . To prove the applicability of the novel vectors for cloning purposes, a 13 kb hemolysin operon of Escherichia coli was inserted into pIV1, and the resulting recombinant plasmid was stably maintained and expressed in E . coli and Y . enterocolitica.

Methods, 2000 Jun, 21(2), 125 - 32
Plasminogen activation in degradation and penetration of extracellular matrices and basement membranes by invasive bacteria; Lahteenmaki K et al.; Methods to assess in vitro the role of plasminogen activation in enterobacterial degradation of extracellular matrices and their protein components as well as in penetration through basement membrane are described . Development of these methods was initiated after the findings that enterobacterial surface structures (fimbriae and the Pla surface protease) function in plasminogen activation as well as in laminin- and/or fibronectin-specific adhesion . Enterobacteria with these properties degrade radiolabeled laminin as well as metabolically labeled extracellular matrix from cultured endothelial or epithelial cells . Plasmin-coated bacteria also penetrate through the reconstituted basement membrane preparation Matrigel . The processes are dependent on plasminogen activation by the invasive bacteria . The results suggest a pathogenic similarity between enterobacteria and tumor cells in cellular metastasis through tissue barriers .

Clin Infect Dis, 2000 May, 30(5), 799 - 808 Epub 2000 Apr 28.
Antimicrobial susceptibility testing: special needs for fastidious organisms and difficult-to-detect resistance mechanisms; Jorgensen JH et al.; Clinical microbiology laboratories are faced with the challenge of accurately detecting emerging antibiotic resistance among a number of bacterial pathogens . In recent years, vancomycin resistance among enterococci has become prevalent, as has penicillin resistance and multidrug resistance in pneumococci . More recently, strains of methicillin-resistant Staphylococcus aureus with reduced susceptibility to vancomycin have been encountered . In addition, molecular techniques have demonstrated that there are still problems detecting methicillin resistance in staphylococci, especially in coagulase-negative species . Among members of the family Enterobacteriaceae, mutated beta-lactamase enzymes may confer difficult-to-detect resistance to later-generation penicillins and cephalosporins . Anaerobic bacteria are no longer entirely predictable in their susceptibility to agents that might be selected for empiric therapy . Therefore, clinical microbiology laboratories may not be able to rely on a single susceptibility testing method or system to detect all those emerging resistant or fastidious organisms . For reliable detection, laboratories may need to employ conventional, quantitative susceptibility testing methods or use specially developed, single concentration agar screening tests for some resistant species . Certain of these screening tests are highly specific, while others may require additional confirmatory testing for definitive results . Therefore, laboratories must retain the versatility to apply several different approaches to detect resistance in both common and infrequently encountered bacterial pathogens.

Transfus Clin Biol, 2000 Apr, 7(2), 171 - 6
{Prevalence of bacterial contamination of standard platelet units: prospective study}; Loukhmas L et al.; BACKGROUND: Platelet concentrates contaminated with bacteria are a main source of transfusion-associated sepsis . Several studies have reported a very wide incidence (0-10%) of contamination . The aim of this study is to assess the prevalence of bacterial contamination of standard platelet units at the regional blood transfusion center in Casablanca . STUDY DESIGN AND METHODS: During 15.5 months, 3,458 platelet concentrates (PCs) were analysed . The plasma from the bag and the tube was homogenised . One-fifth of the tube contents were inoculated every day for five days in two tubes containing 2.5 mL of Tryptic soy broth . One tube was incubated at room temperature and the other at 37 degrees C for 24 hours . The bacteria were identified by standard procedures . RESULTS: Twenty-five (0.72%) of 3,458 platelet bags were contaminated . Twenty-two bacteria (88%) were found in the platelet bags stored three days or more, of which 14 (56%) were Staphylococci coagulase negative, two Staphylococcus aureus, one alpha-haemolytic Streptococcus, four bacillus cereus, one Enterobacter cloacae, one Escherichia Coli and two Xanthomonas maltophilia . CONCLUSION: The incidence reported in this series is higher than that reported by most authors.

Am J Gastroenterol, 2000 May, 95(5), 1231 - 8
Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome; Nobaek S et al.; OBJECTIVE: The influence of the gastrointestinal (GI) microflora in patients with irritable bowel syndrome (IBS) has not been clearly elucidated . This study was undertaken to see if patients with IBS have an imbalance in their normal colonic flora, as some bacterial taxa are more prone to gas production than others . We also wanted to study whether the flora could be altered by exogenous supplementation . In a previous study we have characterized the mucosa-associated lactobacilli in healthy individuals and found some strains with good colonizing ability . Upon colonization, they seemed to reduce gas formation . METHODS: The study comprised 60 patients with IBS and a normal colonoscopy or barium enema . Patients fulfilling the Rome criteria, without a history of malabsorption, and with normal blood tests underwent a sigmoidoscopy with biopsy . They were randomized into two groups, one receiving 400 ml per day of a rose-hip drink containing 5 x 10(7) cfu/ml of Lactobacillus plantarum (DSM 9843) and 0.009 g/ml oat flour, and the other group receiving a plain rose-hip drink, comparable in color, texture, and taste . The administration lasted for 4 wk . The patients recorded their own GI function, starting 2 wk before the study and continuing throughout the study period . Twelve months after the end of the study all patients were asked to complete the same questionnaire regarding their symptomatology as at the start of the study . RESULTS: All patients tolerated the products well . The patients receiving Lb . plantarum had these bacteria on rectal biopsies . There were no major changes of Enterobacteriaceae in either group, before or after the study, but the Enterococci increased in the placebo group and remained unchanged in the test group . Flatulence was rapidly and significantly reduced in the test group compared with the placebo group (number of days with abundant gas production, test group 6.5 before, 3.1 after vs 7.4 before and 5.6 after for the placebo group) . Abdominal pain was reduced in both groups . At the 12-month follow-up, patients in the test group maintained a better overall GI function than control patients . There was no difference between the groups regarding bloating . Fifty-nine percent of the test group patients had a continuous intake of fermented products, whereas the corresponding figure for the control patients was 73% . CONCLUSIONS: The results of the study indicate that the administration of Lb . plantarum with known probiotic properties decreased pain and flatulence in patients with IBS . The fiber content of the test solution was minimal and it is unlikely that the fiber content could have had any effect . This type of probiotic therapy warrants further studies in IBS patients.

J Biol Chem, 2000 May 19, 275(20), 15526 - 34
ATP modulates subunit-subunit interactions in an ATP-binding cassette transporter (MalFGK2) determined by site-directed chemical cross-linking; Hunke S et al.; The binding protein-dependent maltose transport system of enterobacteria (MalFGK(2)), a member of the ATP-binding cassette (ABC) transporter superfamily, is composed of two integral membrane proteins, MalF and MalG, and of two copies of an ATPase subunit, MalK, which hydrolyze ATP, thus energizing the translocation process . In addition, an extracellular (periplasmic) substrate-binding protein (MalE) is required for activity . Ligand translocation and ATP hydrolysis are dependent on a signaling mechanism originating from the binding protein and traveling through MalF/MalG . Thus, subunit-subunit interactions in the complex are crucial to the transport process but the chemical nature of residues involved is poorly understood . We have investigated the proximity of residues in a conserved sequence ("EAA" loop) of MalF and MalG to residues in a helical segment of the MalK subunits by means of site-directed chemical cross-linking . To this end, single cysteine residues were introduced into each subunit at several positions and the respective malF and malG alleles were individually co-expressed with each of the malK alleles . Membrane vesicles were prepared from those double mutants that contained a functional transporter in vivo and treated with Cu(1,10-phenanthroline)(2)SO(4) or bifunctional cross-linkers . The results suggest that residues Ala-85, Lys-106, Val-114, and Val-117 in the helical segment of MalK, to different extents, participate in constitution of asymmetric interaction sites with the EAA loops of MalF and MalG . Furthermore, both MalK monomers in the complex are in close contact to each other through Ala-85 and Lys-106 . These interactions are strongly modulated by MgATP, indicating a structural rearrangement of the subunits during the transport cycle . These data are discussed with respect to current transport models.

Chest, 2000 May, 117(5), 1434 - 42
A comparative analysis of patients with early-onset vs late-onset nosocomial pneumonia in the ICU setting; Ibrahim EH et al.; STUDY OBJECTIVE: To compare the clinical outcomes of critically ill patients developing early-onset nosocomial pneumonia (NP; ie, within 96 h of ICU admission) and late-onset NP (ie, occurring after 96 h of ICU admission) . DESIGN: Prospective cohort study . SETTING: A medical ICU and a surgical ICU from a university-affiliated urban teaching hospital . PATIENTS: Between July 1997 and November 1998, 3, 668 patients were prospectively evaluated . INTERVENTION: Prospective patient surveillance and data collection . RESULTS: Four hundred twenty patients (11.5%) developed NP . Early-onset NP was observed in 235 patients (56.0%), whereas 185 patients (44.0%) developed late-onset NP . Among patients with early onset NP, 114 patients (48 . 5%) spent at least 24 h in the hospital prior to ICU admission, compared to 57 patients (30.8%) with late-onset NP (p = 0.001) . One hundred eighty-three patients (77.9%) with early-onset NP received antibiotics prior to the development of NP, as compared to 162 patients (87.6%) with late-onset NP (p = 0.010) . The most common pathogens associated with early-onset NP were Pseudomonas aeruginosa (25.1%), oxacillin-sensitive Staphylococcus aureus (OSSA; 17.9%), oxacillin-resistant S aureus (ORSA; 17.9%), and Enterobacter species (10.2%) . P aeruginosa (38.4%), ORSA (21.1%), Stenotrophomonas maltophilia (11.4%), OSSA (10.8%), and Enterobacter species (10.3%) were the most common pathogens associated with late-onset NP . The ICU length of stay was significantly longer for patients with early-onset NP (10.3 +/- 8.3 days; p < 0.001) and late-onset NP (21 . 0 +/- 13.7 days; p < 0.001), as compared to patients without NP (3.5 +/- 3.2 days) . Hospital mortality was significantly greater for patients with early-onset NP (37.9%; p = 0.001) and late-onset NP (41.1%; p = 0.001) compared to patients without NP (13.1%) . CONCLUSIONS: Both early-onset and late-onset NP are associated with increased hospital mortality rates and prolonged lengths of stay . The pathogens associated with NP were similar for both groups . This may be due, in part, to the prior hospitalization and use of antibiotics in many patients developing early-onset NP . These data suggest that P aeruginosa and ORSA can be important pathogens associated with early-onset NP in the ICU setting . Additionally, clinicians should be aware of the common microorganisms associated with both early-onset NP and late-onset NP in their hospitals in order to avoid the administration of inadequate antimicrobial treatment.

Spine, 2000 May 15, 25(10), 1287 - 9
Enterobacter agglomerans spondylodiscitis: a possible, unrecognized complication of tetracycline therapy; Porter P et al.; STUDY DESIGN: This case report describes infection in a lumbar disc in a healthy young man with an organism of low pathogenicity . The patient was taking a prolonged course of antibiotics at the time the infection occurred . OBJECTIVE: To describe this unique case of infective spondylodiscitis . SUMMARY OF BACKGROUND DATA: To the authors' knowledge, spinal infection with Enterobacter agglomeranshas never been reported . This organism is a transient gut colonizer, and may have established itself secondary to the patient's prolonged ingestion of tetracycline for acne . METHODS: This 22-year-old farmer had spontaneous lumbar back pain . Radiologic investigations showed an abnormality in the L4-L5 disc region, and together with other investigations, were suggestive of infection . The diagnosis was confirmed by surgical aspiration . RESULTS: Antibiotic therapy was administered, and the patient made a complete recovery . Follow-up radiographs showed a complete loss of the L4-L5 disc space with only minimal bone destruction . CONCLUSION: A unique cause of infective lumbar discitis is presented . Several features of this case are unusual . The magnetic resonance findings were not readily diagnostic . The cultured organism is usually nonpathogenic . The infection may have been secondary to prolonged tetracycline therapy.

Rinsho Byori, 2000 Jan, Suppl 111, 9 - 16
{Drug-resistant bacteria in clinical situations}; Watanabe A; There are two major categories of drug-resistant bacteria that can cause severe and intractable infections . The first includes multi drug-resistant Mycobacterium tuberculosis(MDRMT), penicillin-resistant Streptococcus pneumoniae(PRSP), and beta-lactamase positive or negative ampicillin-resistant Haemophilus influenzae, which used to be isolated from the patients with community-acquired infection . However, these pathogens have been often isolated in recent years from patients with hospital/chronic care facilities/nursing-home mass infection . The second major category includes methicillin-resistant Staphylococcus aureus(MRSA), vancomycin-resistant Enterococcus species(VRE), Pseudomonas aeruginosa, and Enterobacteriaceae including extended-spectrum beta-lactamases(ESBLs) producing strain, which are mainly isolated from compromised patients with nosocomial infections . The pathogenicity of these pathogens, almost all of which are found in the normal flora of humans, is weak, but often cause nosocomial infections in compromised patients . We need, therefore, surveillance system for these pathogens, and carefully determine whether these pathogens, if isolated, are causative pathogens.

Med Dosw Mikrobiol, 1999, 51(3-4), 357 - 62
{Peritonitis determined by the site of intra-abdominal surgery}; Chylak J et al.; The aim of this study was to determine bacterial flora infecting the peritoneal cavity during intraabdominal surgery by site of operation . Three groups of patients were examined . 29 patients who underwent surgery on the stomach, duodenum, biliary tract or pancreas, 15 patients operated on because of acute appendicitis and 63 patients operated on because of colon or rectum tumours . At the end of the operation but before closure cultures were obtained by swab from the completed anastomosis site . Samples were placed into transport medium and transported promptly to the laboratory . The results of the bacteriological examinations showed that the peritoneal cavity of all patients operated on were infected with bacteria characteristic for the digestive tract, especially by Enterobacteriaceae spp., Enterococcus spp . and Bacteroides spp . From patients operated on because of rectum or colon tumours 3 or 4 bacterial species were isolated most often and they were often infected with P . aeruginosa and C . albicans . This was in contrast to patients from the other groups . In patients infected with polymicrobial flora, B . fragilis and E . coli or enterococci and E . coli and enterococci were most often seen.

Postepy Hig Med Dosw, 2000, 54(1), 3 - 15
{REP and ERIC repetitive DNA sequences in bacteria--diagnostic significance}; Ugorski M et al.; Main part of eukaryotic genomes is build of unique sequences coding proteins and RNAs, but they contain as well numerous repeats interspersed with single-copy fragments . Existence of repetitive sequences were also demonstrated in prokaryotic genomes . They are found in different species of Gram-negative and Gram-positive bacteria . Interspersed repetitive sequence elements called REP and ERIC sequences are present in different species of Enterobacteriaceae family, including Escherichia coli and Salmonella typhimurium . Their functions are not completely clear, probably they play important role in regulation of gene expression . Nevertheless, REP and ERIC elements are widely use in identification and genetic analysis of bacteria . For example, using rep-PCR technique it is possible to discriminate between closely related serovars of the same species, which enables to analyze phylogenetic and epidemiological relations among them.

Alcohol Clin Exp Res, 2000 Apr, 24(4), 570 - 5
Metronidazole increases intracolonic but not peripheral blood acetaldehyde in chronic ethanol-treated rats; Tillonen J et al.; BACKGROUND: Metronidazole leads to the overgrowth of aerobic flora in the large intestine by reducing the number of anaerobes . According to our previous studies, this shift may increase intracolonic bacterial acetaldehyde formation if ethanol is present . Metronidazole is also reported to cause disulfiram-like effects after alcohol intake, although the mechanism behind this is obscure . Therefore, the aim was to study the effect of long-term metronidazole and alcohol treatment on intracolonic acetaldehyde levels and to explore the possible role of intestinal bacteria in the metronidazole related disulfiram-like reaction . METHODS: A total of 32 rats were divided into four groups: controls (n = 6), controls receiving metronidazole (n = 6), ethanol group (n = 10), and ethanol and metronidazole group (n = 10) . All rats were pair-fed with the liquid diet for 6-weeks, whereafter blood and intracolonic acetaldehyde levels and liver and colonic mucosal alcohol (ADH) and aldehyde dehydrogenase (ALDH) activities were analyzed . RESULTS: The rats receiving ethanol and metronidazole had five times higher intracolonic acetaldehyde levels than the rats receiving only ethanol (431.4 +/- 163.5 microM vs . 84.7 +/- 14.4 microM,p = 0.0035) . In contrast, blood acetaldehyde levels were equal . Cecal cultures showed the increased growth of Enterobacteriaceae in the metronidazole groups . Metronidazole had no inhibitory effect on hepatic or colonic mucosal ADH and ALDH activities . CONCLUSIONS: The increase in intracolonic acetaldehyde after metronidazole treatment is probably due to the replacement of intestinal anaerobes by ADH-containing aerobes . Unlike disulfiram, metronidazole neither inhibits liver ALDH nor increases blood acetaldehyde . Thus, our findings suggested that the mechanism behind metronidazole related disulfiram-like reaction might be located in the gut flora instead of the liver.

Dakar Med, 1999, 44(1), 69 - 75
{Micromethod for identification of enterobacteria}; Gassama A et al.; The aim of this study was to set accurate and reliable methods in the identification of Enterobacteriaceae . In Micro CSB Entero each of a strip with 20 cupules containing dehydrated substrates for biochemical identification of bacterial species . Strips were inoculated with 100 microliters per cupule and incubated . After 18 hours, reagents were added . Baye's theorem was used to validate tests . Reactions from Micro CSB were cleared and easily read . 102 strains of Enterobacteriaceae were identified by MicroCSB--89.3% were correctly identified . 0.9% were identified with other tests 9.8% were incorrectly identified MicroCSB gives many advantages: This method save time, space and is less expensive than the other methods and it gives security for identifying species belonging to the different genera.

Dakar Med, 1999, 44(1), 20 - 4
{Sensitivity to cotrimoxazole of bacteria isolated at the Central University Hospital of Fann, Dakar}; Sow AI et al.; This study concern a survey of bacterial resistance to cotrimoxazole; 510 strains of Enterobacteria (167), Vibrio cholerae(206) and Staphylococcus aureus(137) were tested by disc diffusion and agar dilution methods . An interview was conducted with 86 health personals to appreciate the influence of prescription . Staphylococcus aureus were the most susceptible bacteria (13% of resistance), and Vibrio cholerae the most resistant (95%) . Related to the gender, Enterobacteria present 43 to 72% of resistance . The data of interview show a very frequent use of cotrimoxazole, related to the disponibility and the accessibility of this drug.

Diagn Microbiol Infect Dis, 2000 May, 37(1), 41 - 4
Comparative in vitro bactericidal activity between cefepime and ceftazidime, alone and associated with amikacin, against carbapenem-resistant Pseudomonas aeruginosa strains; Bantar C et al.; Fifteen unique isolates of carbapenem-resistant Pseudomonas aeruginosa were selected for time-kill studies to assess the bactericidal activity of cefepime (CFP) and ceftazidime (CZD) (at 4 and 16 microg/mL), alone and associated with amikacin (AMK) (4 microg/mL) . CFP proved more active than CZD (p < 0.05, Student's t test) . Bactericidal activity after 24-h incubation was only achieved by the combination of CFP (16 microg/mL) plus AMK . The higher in vitro activity of cefepime over that of ceftazidime against imipenem-resistant P . aeruginosa strains highlights the differences of these drugs beyond Enterobacterspp . and Staphylococcus aureus.

Biochem J, 2000 May 15, 348 Pt 1, 223 - 7
Comparative aspects of the diffusion of norfloxacin, cefepime and spermine through the F porin channel of Enterobacter cloacae; Chevalier J et al.; In Enterobacteriaceae, the permeability of the outer membrane to hydrophilic antibiotics is associated with the presence of pore-forming proteins . We tested the diffusion of the fluoroquinolone norfloxacin in four Enterobacter cloacae strains: a clinical isolate and three derivatives variously producing or lacking the D and F porins . We analysed the entry of norfloxacin into E . cloacae cells in the presence of either the polyamine spermine or the recently developed cefepime, which are known to penetrate through the Escherichia coli OmpF porin . Uptake of the fluoroquinolone was decreased in both cases; the initial rate of penetration decreased as more spermine blocked the channel . Our results indicate that, like beta-lactam molecules, fluoroquinolones translocate through the outer membrane via the F porin and that cefepime and norfloxacin entries are polyamine-sensitive . This suggests that the closure of the F porin channel by polyamines might modulate the susceptibility of E . cloacae to both fluoroquinolone and cephalosporin antibiotics.

Food Addit Contam, 2000 Jan, 17(1), 17 - 25
Shelf-life extension of cod fillets with an acetate buffer spray prior to packaging under modified atmospheres; Boskou G et al.; Fresh cod fillets (Gadus morhua) were sprayed with a 10% acetate buffer (pH 5.6), packed with an industrial gas-flushing packaging machine under modified atmospheres (50% CO2--45% O2--5% N2, 2 cm3/1 g gas/product ratio) and stored at 7 degrees C for 12 days . Control cod fillets were directly packed and stored under the same conditions . A reduction of the aerobic plate counts was observed immediately after the cod fillets had been sprayed . During storage under modified atmospheres, there was complete inhibition of H2S-producing bacteria and Enterobacteriaceae in the treated cod fillets . Production of total volatile bases and trimethylamine (TMA) was inhibited in treated fillets for 10 days' storage under modified atmospheres . Inhibition of TMA production can be attributed to growth inhibition of H2S-producing bacteria, inhibition of the trimethylamine oxide (TMAO)-dependent metabolism of TMAO-reducing bacteria and the stable pH during storage . The shelf-life, at 7 degrees C, of treated cod fillets, based on cooked flavour score, was almost 12 days, ca 8 days more than shelf-life of the control fillets.

Am J Vet Res, 1999 Oct, 60(10), 1322 - 7
Characterization of swimming motility and identification of flagellar proteins in Salmonella pullorum isolates; Chaubal LH et al.; OBJECTIVE: To identify swimming motility in Salmonella pullorum isolates and to characterize the flagellar proteins produced by motile isolates . SAMPLE POPULATION: 30 S pullorum isolates and isolates of 7 other Salmonella sp . PROCEDURE: Salmonella pullorum isolates were inoculated into high motility medium to evaluate swimming motility . Putative flagellar proteins were purified from the organisms and analyzed by means of gel electrophoresis and western blotting procedures, using various antisera specific for flagellar proteins . Antisera shown to be reactive with putative flagellar proteins were incorporated into the growth medium to examine their effects on motility of the isolates . RESULTS: All S pullorum isolates had evidence of swimming motility . Two putative flagellar proteins were purified from 2 of the S pullorum isolates: a 60 to 62 kd protein shown to react with antiserum specific for type y flagellar protein, and a 58 to 59 kd protein shown to react with antiserum specific for type d flagellar protein and with antibody reactive to a highly conserved flagellar epitope found on various Enterobacteriaceae . Antiserum specific for type d flagellar protein inhibited swimming motility of S pullorum isolates, but antiserum specific for type y flagellar protein did not . CONCLUSIONS: Results suggest that S pullorum isolates can be induced to manifest swimming motility when grown on medium with a low agar concentration and possess a 58 to 59 kd protein of d serotype and a second protein of 60 to 62 kd that also may be a flagellar protein.

Urology . 2000 May 1;55(5):774.
Complications of intrauterine intervention for treatment of fetal obstructive uropathy; Irwin BH et al.; The intrauterine surgical placement of vesicoamniotic shunts in the treatment of fetal obstructive uropathy associated with prune-belly syndrome to avoid such complications as renal damage and oligohydramnios remains controversial . We present a case of an infant born with prune-belly syndrome at 33 weeks and 5 days of estimated gestational age to a mother of two by vaginal delivery after a pregnancy complicated by fetal obstructive uropathy with attempted intrauterine intervention . After sonographic and laboratory diagnostic and prognostic evaluations, an intrauterine procedure was performed in which a vesicoamniotic shunt was placed under ultrasound guidance . Complications included dislodgment of the initial shunt, with a failed subsequent attempt at placement, oligohydramnios, preterm labor and delivery, and traumatic gastroschisis through the surgical abdominal wall defect . His hospital stay was further complicated by chronic renal insufficiency, prematurity, respiratory distress, bowel malrotation, an episode of gram-negative sepsis with Enterobacter cloacae, signs of liver failure, an exploratory laparotomy for severe enterocolitis, and orchiopexy for bilateral undescended testes . At present, it is unclear whether vesicoamniotic shunt placement can provide any significant improvement in the morbidity or mortality for patients with prune-belly syndrome . A large, prospective, randomized trial is needed to determine its efficacy.

J Chemother, 2000 Apr, 12(2), 115 - 23
Antibiotic prophylaxis in children with relapsing urinary tract infections: review; Mangiarotti P et al.; Recurrent urinary tract infections (UTIs) are observed in 30-50% of children after the first UTI . Of these, approximately 90% occur within 3 months of the initial episode . The basic aim of antibiotic prophylaxis in children with malformative uropathy and/or recurrent UTIs, is to reduce the frequency of UTIs . The bacteria most frequently responsible for UTI are gram-negative organisms, with Escherichia coli accounting for 80% of urinary tract pathogens . In children with recurrent UTIs and in those treated with antibiotic prophylaxis there is a greater incidence of UTI due to Proteus spp., Klebsiella spp . and Enterobacter spp., whereas Pseudomonas spp., Serratia spp . and Candida spp . are more frequent in children with urogenital abnormalities and/or undergoing invasive instrumental investigations . Several factors are involved in the pathogenesis of UTI, the main ones being circumcision, periurethral flora, micturition disorders, bowel disorders, local factors and hygienic measures . Several factors facilitate UTI relapse: malformative uropathies, particularly of the obstructive type; vesico-ureteric reflux (VUR); previous repeated episodes of cystitis and/or pyelonephritis (3 or more episodes a year), even in the absence of urinary tract abnormalities; a frequently catheterized neurogenic bladder; kidney transplant . The precise mechanism of action of low-dose antibiotics is not yet fully known . The characteristics of the ideal prophylactic agent are presented in this review, as well as indications, dosages, side effects, clinical data of all molecules . While inappropriate use of antibiotic prophylaxis encourages the emergence of microbial resistance, its proper use may be of great value in clinical practice, by reducing the frequency and clinical expression of UTIs and, in some cases such as VUR, significantly helping to resolve the underlying pathology.

Przegl Lek, 1999, 56(12), 755 - 9
{Participation of multiresistant gram-negative rods in systemic infections of newborns treated in the Neonatal Clinics of the University Hospital in Krakow in 1993-1997}; Kedzierska J et al.; Results of blood cultures in 1187 newborns hospitalized in the Department of Neonatology, University Hospital in Krakow in furing the last five years were analysed . A trial of monitoring the presence of multi-resistant strains of Enterobacteriaceae with new mechanisms of resistance to antibiotics as well as analysed of their antibiotics susceptibility patterns were undertaken . Surprisingly high percentage of Gram-negative rods E . cloacae and K . pneumoniae strains resistant to the 3rd generation of cephalosporins and participating in septic complications in the investigated hospital environment was demonstrated . There were identified 53 strains of Enterobacter sp., 35 strains of Klebsiella sp . and 3 strains of E . coli extremely resistant to ceftazidine, accounting for 72%, 56% and 5% of all isolated of the given kind, respectively . Dynamic increase in a number of multiresistant strains of K . pneumoniae from 11.1% of isolates in 1993 to 83% in 1997 was shown as well as remaining on a very high level frequency of isolation of Enterobacter sp . rods capable of producing chromosomal cephalosporinases was demonstrated . Full efficacy of carbapenems and high usefulness of ciprofloxacine in the treatment of infections were confirmed . The authors emphasize necessity for constant monitoring of susceptibility to antibiotics in resistant strains as well as for liquidating their sources and ways of their transmission.

Appl Environ Microbiol, 2000 May, 66(5), 1862 - 5
Increased killing of Bacillus subtilis on the hair roots of transgenic T4 lysozyme-producing potatoes; Ahrenholtz I et al.; Transgenic potato plants expressing the phage T4 lysozyme gene which are resistant to the plant-pathogenic enterobacterium Erwinia carotovora subsp . carotovora have been constructed . The agricultural growth of these potatoes might have harmful effects on soil microbiota as a result of T4 lysozyme release into the rhizosphere . To assess the bactericidal effect of roots, we have developed a novel method to associate the cells of Bacillus subtilis with hair roots of plants and to quantify the survival of cells directly on the root surface by appropriate staining and fluorescence microscopy . With this technique, we found that the roots of potato plants (Desiree and transgenic control lines) without T4 lysozyme gene display measurable killing activity on root-adsorbed B . subtilis cells . Killing was largely independent of the plant age and growth of plants in greenhouse or field plots . Roots from potato lines expressing the T4 lysozyme gene always showed significantly (1.5- to 3.5-fold) higher killing . It is concluded that T4 lysozyme is released from the root epidermis cells and is active in the fluid film on the root surface . We discuss why strong negative effects of T4 lysozyme-producing potatoes on soil bacteria in field trials may not be observed . We propose that the novel method presented here to study interactions of bacteria with roots can be applied not only to bacterial killing but also to interactions leading to growth-sustaining effects of plants on bacteria.

Acta Clin Belg, 2000 Jan-Feb, 55(1), 16 - 21
Comparative in vitro activity of cefepime against strains isolated from intensive care and haematology patients; Vanpoucke H et al.; The aim of the study was to evaluate cefepime, a "fourth generation" cephalosporin, for its in vitro activity in comparison with 5 other broad spectrum antibiotics against clinical isolates from ICU and haematology patients . The strains were isolated from blood (8%), lower respiratory tract (41%), upper respiratory tract (14%), urine (20%) and other sites (17%) . They were divided into: 28 non-inducible Enterobacteriaceae, 35 inducible Enterobacteriaceae, 20 non-fermenters, 10 S . aureus and 10 Streptococcus spp . The MIC-values were determined by E-test . Overall, the rank order of susceptibility was cefepime (93%), imipenem (90%), piperacillin-tazobactam (81%), ciprofloxacin (79%), ceftriaxone (75%) and ceftazidime (74%) . Only cefepime was able to inhibit all inducible Enterobacteriaceae . Against Pseudomonas aeruginosa, cefepime had the same activity as ceftazidime . With the exception of ceftazidime (65%), all beta lactams demonstrated good activity against Gram positive cocci . The excellent activity against most Gram negative and Gram positive pathogens suggests that cefepime may be useful in the treatment of serious infections in the described patient population.

Poult Sci, 2000 Apr, 79(4), 483 - 8
Physical, chemical, and microbiological changes in the ceca of broiler chickens subjected to incremental feed withdrawal; Hinton A Jr et al.; Trials were conducted to determine the effect of feed withdrawal on the weight, pH, native bacterial flora, and the persistence of Salmonella typhimurium in the ceca of market-age broilers . Broilers were provided medicated or unmedicated feed and then were subjected to feed withdrawal for 0 to 24 h in transportation crates or on litter . After feed withdrawal, broilers were stunned, bled, scalded, and picked . One cecum from each bird was aseptically removed and weighed . The cecum was then blended in 20 mL of distilled water, and the pH of the blended suspension was measured . The number of total aerobes, Enterobacteriaceae, S . typhimurium, and lactic acid bacteria in the suspension were enumerated on the appropriate bacteriological media . Results indicated that up to 24 h of feed withdrawal produced no significant change in cecal weight and that cecal pH varied by up to 0.3 units during feed withdrawal . There were significant increases in the population of Enterobacteriaceae during feed withdrawal in Trials 2 and 3, and there was a significant increase in the population of cecal aerobes in Trial 3 . Feed withdrawal produced significant decreases in the population of lactic acid bacteria in all trials, but no significant change in the population of S . typhimurium occurred during feed withdrawal . There were no significant differences in cecal weight, pH, native bacteria populations, or S . typhimurium populations between broilers that were subjected to feed withdrawal on litter or in crates . Findings indicate that feed withdrawal does not always effectively evacuate the contents of the ceca and that the ceca of broilers subjected to feed withdrawal can remain a source of foodborne bacterial pathogens.

Genetika, 2000 Mar, 36(3), 322 - 30
{Cloning and expression of the lux-operon of Photorhabdus luminescens, strain Zm1: nucleotide sequence of luxAB genes and basic properties of luciferase}; Manukhov IV et al.; A chromosomal fragment of bacteria Photorhabdus luminescence Zm1, which contains the lux operon, was cloned into the vector pUC18 . The hybrid clone containing plasmid pXen7 with the EcoRI fragment approximately 7-kb was shown to manifest a high level of bioluminescence . By subcloning and restriction analysis of the EcoRI fragment, the location of luxCDABE genes relative to restriction sites was determined . The nucleotide sequence of the DNA fragment containing the luxA and luxB genes encoding alpha- and beta-subunits of luciferase was determined . A comparison with the nucleotide sequences of luxAB genes in Hm and Hw strains of Ph . luminescence revealed 94.5 and 89.7% homology, respectively . The enterobacterial repetitive intergenic sequence (ERIC) of 126 bp typical for Hw strains was identified in the spacer between the luxD and luxA genes . The lux operon of Zm1 is assumed to emerge through recombination between Hm and Hw strains . Luciferase of Ph . luminescence was shown to possess a high thermal stability: its activity decreased by a factor of 10 at 44 degrees C for 30 min, whereas luciferases of marine bacteria Vibrio fischeri and Vibrio harveyi were inactivated by one order of magnitude at 44 degrees C for 1 and 6 min, respectively . The lux genes of Ph . luminescence are suggested for use in gene engineering and biotechnology.

Southeast Asian J Trop Med Public Health, 1999 Sep, 30(3), 546 - 8
Analysis of blood culture isolates from hospitalized neonates in Nepal; Karki BM et al.; Clinically suspected 77 cases of neonatal septicemia admitted to the pediatric ward of BP Koirala Institute of Health Sciences, Dharan, Nepal, were evaluated by blood culture . The blood culture was positive for bacterial growth in 46 (59.7%) cases . Gram-negative bacteria were isolated in 33 (71.7%) cases, the most common being Escherichia coli, followed by Klebsiella spp, Enterobacter spp . Staphylococcus aureus was the most common gram-positive bacteria . The bacterial isolates were most sensitive to gentamicin (74.5%) and ciprofloxacin (74.5%) followed by chloramphenicol (59.9%) . They were most resistant (78.8%) to ampicillin . This study for the first time underlines the pattern of bacterial isolates and their sensitivity pattern to antibiotics in this part of Nepal.

Digestion, 2000, 61(3), 181 - 8
Structure and composition of common bile duct stones in relation to duodenal diverticula, gastric resection, cholecystectomy and infection; Sandstad O et al.; BACKGROUND: Common bile duct stones represent a clinical problem often involving severe infection, cholangitis and cholestasis . Stasis and infection are thought to play a part in the pathogenesis of choledocholithiasis . Investigations on the etiology of common bile duct stones are, however, scarce because of the difficult access to common bile duct stones and bile . In a clinical series of common bile duct stones, we studied the gross appearance of stones extracted endoscopically from the common bile duct and measured the cholesterol and bilirubinate content in order to elucidate factors of importance to etiology . METHODS: In 135 patients treated endoscopically for bile duct stones, the stones or parts of the stones were collected . Appearances of the cut surface of the stones were studied and described . Cholesterol and bilirubinate content were analyzed enzymatically and with infrared spectroscopy . The growth in bile of gas-producing bacteria previously shown to be correlated with enterobacteriacea was investigated . RESULTS: Seventy-five percent of the stones were pigment stones, the majority with concentric pigmented layering . There was good agreement between cholesterol measurements . With a cutoff at 50% for the infrared measurements and 25% for the enzymatic assay only 3 stones were discordant between cholesterol measurements and visual inspection . Twenty-one of 23 patients with a previous Billroth-II gastric resection had pigment stones (p < 0.05) . Gas-producing bacteria were significantly more prevalent in the bile from patients with layered pigment stones . CONCLUSION: Pigment stones with concentric layering highly suggestive of a cyclic process of crystallization were recovered from the common bile duct in 70% of the patients in our series .

J Hosp Infect, 2000 Apr, 44(4), 245 - 53
Preventing pancreatic infection in acute pancreatitis; Qamruddin AO et al.; In acute pancreatitis, pancreatic inflammation may be complicated by the development of pancreatic infection with a high associated mortality . Pancreatic infection is related to the extent of pancreatic inflammation and necrosis and typically occurs in the second or third week of severe disease . It may be associated with a wide range of Gram-positive and Gram-negative bacteria, notably enterobacteria and also with Candida spp . Current surgical practice in the UK is to use prophylactic antimicrobial therapy in patients with severe disease, with the aim of preventing secondary pancreatic infection . Experimental evidence demonstrates that prophylactic antibacterial therapy prevents pancreatic infection and reduces mortality . Furthermore, studies of antibacterial prophylaxis in patients with acute pancreatitis suggest that prophylactic antibacterial therapy is associated with a reduction in mortality, particularly in those with severe disease . In general, broad-spectrum antibiotics have been used in animal and human studies . However, current evidence does not allow comparisons to be made between different antimicrobial agents . Nutritional strategies may also be important in the prevention of pancreatic infection . Enteral, rather than parenteral, nutrition has been associated with an improved clinical outcome in severe pancreatitis .

JPEN J Parenter Enteral Nutr, 2000 Mar-Apr, 24(2), 56 - 60
Effect of oral genistein and isoflavone-free diet on cecal flora and bacterial translocation in antibiotic-treated mice; Wells CL et al.; BACKGROUND: There are several reports indicating that the isoflavone genistein may augment the integrity of the intestinal epithelial barrier as well inhibit bacterial internalization by cultured enterocytes . We speculated that oral genistein might enhance the integrity of the intestinal epithelial barrier as monitored by the extraintestinal dissemination of intestinal bacteria . METHODS: Mice were treated with oral antibiotics to induce cecal bacterial overgrowth accompanied by bacterial translocation of antibiotic-resistant enterobacteria, especially Escherichia coli . These mice were divided into separate groups that included chow-fed mice orally inoculated either with saline, vehicle, or genistein, and mice fed isoflavone-free diet and orally inoculated with either saline, vehicle, or genistein . Intestinal bacterial overgrowth was monitored by quantitative culture of excised ceca and bacterial translocation was monitored by quantitative culture of draining mesenteric lymph nodes . RESULTS: Mice fed the isoflavone-free diet had decreased populations of cecal bacteria compared with chow-fed mice, and bacterial translocation was reduced in chow-fed mice compared with mice fed isoflavone-free diet . However, bacterial translocation was similar in mice given oral genistein compared with appropriate control mice . CONCLUSIONS: Oral genistein had no noticeable effect on bacterial translocation in this model . However, the isoflavone-free diet had an antibacterial effect on cecal flora, and the isoflavone-free diet was associated with decreased numbers of cecal bacteria and decreased incidence of bacterial translocation.

Turk J Pediatr, 1999 Jan-Mar, 41(1), 37 - 42
Epidemiology and antibiotic resistance of gram-negative urinary pathogens in pediatric patients; Gur D et al.; In order to determine the etiological agents and the rate of resistance to various antibiotics, 209 consecutive gram-negative bacteria isolated from children admitted to Hacettepe University Children's Hospital with urinary tract infections were investigated over a three-month period . Of these, 46 (22%) were nosocomial isolates . The most frequently isolated organism was E.coli (n: 141) followed by Klebsiella spp . (39), Proteus spp . (19), Pseudomonas spp . (8) and Enterobacter spp . (2) . In vitro susceptibilities were evaluated by microbroth dilution method, following NCCLS guidelines . Overall, 75 percent of the isolates were resistant to ampicillin, 52 percent were resistant to TMP/SMX and 25 percent to cefuroxime . Amikacin was the most active aminoglycoside; 93 percent of the isolates were susceptible to this agent, while resistance to gentamicin was 21 percent . Resistance to ceftazidime and ceftriaxone was 12 percent and 19 percent, respectively . Overall, resistance to imipenem was one percent and to ciprofloxacin three percent . These in vitro results should be taken into account before initiating empirical therapy; broad spectrum antibiotics should not be used if the isolate is susceptible to the older drugs in order to prevent the increase in resistance.

Infect Immun, 2000 May, 68(5), 2457 - 63
The sigA gene which is borne on the she pathogenicity island of Shigella flexneri 2a encodes an exported cytopathic protease involved in intestinal fluid accumulation; Al-Hasani K et al.; In this study, the sigA gene situated on the she pathogenicity island of Shigella flexneri 2a was cloned and characterized . Sequence analysis showed that sigA encodes a 139.6-kDa protein which belongs to the SPATE (serine protease autotransporters of Enterobacteriaceae) subfamily of autotransporter proteins . The demonstration that SigA is autonomously secreted from the cell to yield a 103-kDa processed form and possesses a conserved C-terminal domain for export from the cell were consistent with the autotransporter pathway of secretion . Functional analysis showed that SigA is a secreted temperature-regulated serine protease capable of degrading casein . SigA was cytopathic for HEp-2 cells, suggesting that it may be a cell-altering toxin with a role in the pathogenesis of Shigella infections . SigA was at least partly responsible for the ability of S . flexneri to stimulate fluid accumulation in ligated rabbit ileal loops.

J Chemother, 2000 Feb, 12(1), 30 - 9
Natural antibiotic susceptibility of Rahnella aquatilis and R . aquatilis-related strains; Stock I et al.; A database is described of the natural susceptibilities of 70 Rahnella strains to 71 antibiotics . MIC values were determined by a microdilution procedure and evaluated by a table calculation program . Rahnella aquatilis and R . aquatilis-related strains were naturally resistant to amoxycillin, ticarcillin, fosfomycin and to antibiotics to which other species of Enterobacteriaceae are also intrinsically resistant, i.e . macrolides (except azithromycin), benzylpenicillin, oxacillin, rifampicin, fusidic acid, lincosamides and glycopeptides . Rahnella strains were also naturally resistant or intermediate to cefazolin, cefuroxime and loracarbef . All rahnellae were naturally sensitive or intermediate to doxycycline, minocycline, aminoglycosides, some penicillins and cephalosporins, carbapenems, aztreonam, quinolones, sulfamethoxazole, trimethoprim, cotrimoxazole, chloramphenicol and nitrofurantoin . Bimodal or broad MIC distributions were seen for several antibiotics, e.g . quinolones and cephalosporins . With the exception of quinolones no differences in natural antibiotic susceptibility were seen between reference strains of Rahnella genomovar 1 (n=6) and 2 (n=7) . Reference strains of genomovar 1 were pyrase-positive and more susceptible to quinolones than reference strains of genomovar 2, which were pyrase-negative . By discrimination of all rahnellae in the pyrase-positive and pyrase-negative strains the MIC distributions for quinolones became smaller and unimodal . Under the conditions described pyrase might be a parameter to differentiate strains of Rahnella genomovars 1 and 2.

J Chemother, 2000 Feb, 12(1), 5 - 16
Microbial ecology and treatment of Helicobacter pylori infections: review; Adamsson I et al.; The aims of the present study were to investigate the ecological disturbances caused by four different anti-H . pylori regimens, to compare different methods for diagnosing H . pylori, and to study the genetic variability of H . pylori . The patients included in the study were all treated at the Center of Gastroenterology, Huddinge University Hospital, Karolinska Institute . All patients were H . pylori-positive before entering the study, confirmed by rapid urease test, histology, culture and urea breath test or PCR . Treatment regimens included in the study were omeprazole alone (OP), in combination with amoxicillin (OA), in combination with amoxicillin and metronidazole (OAM) and in combination with clarithromycin and metronidazole (OCM) . Samples from the mouth (saliva and dental plaque), stomach (biopsies from the gastric mucosa in the corpus and in the antrum) and the intestine (feces) were collected before, during and after treatment . The oral microflora was challenged by the three treatment regimens including antimicrobial agents, with the emergence of resistant streptococci and staphylococci in the OCM group . Bacterial strains in the gastric mucosa increased in numbers during treatment in all treatment groups, probably due to the pH rise, which provides a better environment for the commensal microflora . This overgrowth was especially pronounced during treatment with omeprazole alone (OP), possibly due to the fact that a concomitant suppression exerted by the antimicrobial agents occurred in the other treatment groups . H . pylori was, on the other hand, suppressed during treatment in all treatment groups, possibly due to a direct effect of omeprazole and to the colonization resistance expressed by the normal microflora . An emergence of resistant commensal strains in the gastric mucosa was seen in the OCM and the OAM groups . The intestinal microflora was most altered in the OAM and the OCM groups, with persistent disturbances in the OCM group 4 weeks after treatment . The frequency of resistant Enterococcus spp . (OCM), Enterobacteriaceae spp . (OA and OAM) and Bacteroides spp . (OCM) was increased during and after treatment . Different detection methods for H . pylori were compared and PCR was shown to have higher sensitivity than other routine diagnostic tests . The patients in the present study seemed to be colonized with a single strain of H . pylori . Treatment failures in patients treated with OAM were caused by recrudescence . These four patients with relapsing H . pylori infection, were shown to be reinfected with the original H . pylori strain, indicating that H . pylori escapes treatment by a thus far unknown mechanism.

Antonie Van Leeuwenhoek, 2000 Feb, 77(2), 147 - 52
Antimicrobial resistance among urinary tract infection (UTI) isolates in Europe: results from the SENTRY Antimicrobial Surveillance Program 1997; Fluit AC et al.; The SENTRY Antimicrobial Surveillance Program was established to monitor the occurrence and antimicrobial susceptibility of bacterial pathogens via an international network of sentinel hospitals . Twenty European hospitals referred a total of 887 urinary tract infection (UTI) isolates to the European SENTRY reference laboratory during the period October-December 1997 . Ninety percent of the referred species were represented by Escherichia coli (52%), Enterococcus spp . (12%), Klebsiella spp . (7%), Proteus spp . (7%), Pseudomonas aeruginosa (7%), and Enterobacter spp . (5%) . The susceptibility of E . coli isolates to penicillins was less than 60%, while almost all of the isolates were susceptible to piperacillin/tazobactam (98% susceptibility), cephalosporins (98%), and carbapenems (100%) . Amikacin was the best aminoglycoside (99.8% susceptibility) . The susceptibility to quinolones was only 88-89%, with highest levels of resistance observed for isolates from Portugal, Italy, England, The Netherlands, and some centers in France, Spain, and Poland . The susceptibility of Klebsiella spp . to the newer generations of cephalosporins was 82-95% and to the carbapenems 100% . Amikacin was again the best aminoglycoside (94% susceptibility) . The susceptibility of Enterobacter spp . to any beta-lactam antibiotic was poor, except for the carbapenems (100% susceptibility) and cefepime (90% susceptibility), while the susceptibility to aminoglycosides was 80-89% . Proteus spp . showed complete susceptibility to cefepime, ceftriaxone, the carbapenems, and piperacillin/tazobactam, while the susceptibility of P . aeruginosa isolates was poor, with best results for the carbapenems (susceptibility 89%), piperacillin/tazobactam (susceptibility 84%), and amikacin and ticarcillin (susceptibility to both 80%) . Enterococcus spp . showed the highest susceptibility to vancomycin (98%), teicoplanin (98%), and ampicillin (94%).

Lancet, 2000 Mar 18, 355(9208), 973 - 8
An antibiotic policy to prevent emergence of resistant bacilli; de Man P et al.; BACKGROUND: Fear of infection in neonatal intensive care units (NICUs) often leads to early use of empiric broad-spectrum antibiotics, a strategy that selects for resistant bacteria . We investigated whether the emergence of resistant strains could be halted by modifying the empiric antibiotic regimens to remove the selective pressure that favours resistant bacteria . METHODS: Two identical NICUs were assigned to different empiric antibiotic regimens . On unit A, penicillin G and tobramycin were used for early-onset septicaemia, flucloxacillin and tobramycin were used for late-onset septicaemia, and no broad-spectrum beta-lactam antibiotics, such as amoxicillin and cefotaxime were used . In unit B, intravenous amoxicillin with cefotaxime was the empiric therapy . After 6 months of the study the units exchanged regimens . Rectal and respiratory cultures were taken on a weekly basis . FINDINGS: There were 436 admissions, divided equally between the two regimens (218 in each) . Three neonates treated with the penicillin-tobramycin regimen became colonised with bacilli resistant to the empirical therapy used versus 41 neonates on the amoxicillin-cefotaxime regimen (p<.0001) . The relative risk for colonisation with strains resistant to the empirical therapy per 1000 patient days at risk was 18 times higher for the amoxicillin-cefotaxime regimen compared with the penicillin-tobramycin regimen (95% CI 5.6-58.0) . Enterobacter cloacae was the predominant bacillus in neonates on the amoxicillin-cefotaxime regimen, whereas Escherichia coli predominated in neonates on the penicillin-tobramycin regimen . These colonisation patterns were also seen when the units exchanged regimens . INTERPRETATION: Policies regarding the empiric use of antibiotics do matter in the control of antimicrobial resistance . A regimen avoiding amoxicillin and cefotaxime restricts the resistance problem.

J Mass Spectrom, 2000 Mar, 35(3), 361 - 8
Confirmation of the structure of lipid A from Enterobacter agglomerans by electrospray ionization tandem mass spectrometry
Boue SM, Cole RB.
Electrospray ionization (ESI) combined with tandem mass spectrometry (MS/MS) was utilized for the structural confirmation of lipid A derived from Enterobacter agglomerans, a Gram-negative bacterium commonly found in field cotton . Previous ESI-MS studies conducted in our laboratory found that similarities exist between the fatty acid side-chains in the lipid A of E . agglomerans and that of Salmonella minnesota . It was noted that heterogeneity at the fatty acyl chain at position 3' of the diglucosamine backbone of E . agglomerans can take the form of either a myristyloxymyristyl group or, less commonly, a hydroxymyristyloxymyristyl moiety . In this work, tandem mass spectra obtained from heptaacyl and hexaacyl lipid A precursors derived from E . agglomerans and a known standard S . minnesota were compared to assist in structural elucidation . These ESI-MS/MS experiments confirmed the previously reported structure for lipid A derived from E . agglomerans . Moreover, MS/MS data indicated that the additional hydroxyl group of the 3'-position hydroxymyristyloxymyristyl moiety is present as the alpha-isomer.

Am J Infect Control, 2000 Apr, 28(2), 123 - 9
Enterobacterial repetitive intergenic consensus polymerase chain reaction typing of isolates of Enterobacter cloacae from an outbreak of infection in a neonatal intensive care unit; Peters SM et al.; BACKGROUND: Enterobacter cloacae has become a common cause of nosocomial infections . This study was designed to investigate the pattern of spread of E cloacae during an outbreak in a neonatal intensive care unit . METHODS: Enterobacterial repetitive intergenic consensus polymerase chain reaction was used to examine 111 E cloacae isolates from 17 patients, including 81 from surveillance cultures, 23 from endotracheal tubes, 3 from eyes, and 1 each from blood, urine, skin, and throat . Antibiotic susceptibility profiles were also obtained . RESULTS: Infection with E cloacae resulted from endogenous bacteria and from horizontal transmission . One group of 61 isolates, a third of which were obtained from clinical specimens, was uniformly susceptible to imipenem and ciprofloxacin only . A second group of 50 isolates, only 18% of which were obtained from clinical specimens, was susceptible to all antibiotics tested except for aminopenicillins and first-generation cephalosporins . CONCLUSION: These data indicate that (1) patient-to-patient spread is an important cause of E cloacae infection in the neonatal intensive care unit and (2) highly antibiotic-resistant E cloacae may emerge during an outbreak.

Int J Radiat Oncol Biol Phys, 2000 Apr 1, 47(1), 171 - 8
Neonatal neoplasms; Halperin EC; PURPOSE: To describe neoplasms diagnosed in children </= 28 days of age along with their treatment, associated congenital anomalies, and the long-term consequences of the diagnoses and treatments . METHODS AND MATERIALS: Utilizing autopsy records, a computerized tumor registry, and medical records, we identified patients and stillborns at Duke University Medical Center (DUMC) diagnosed with neoplasms at </= 28 days of age between 1930 and 1998 . RESULTS: Twenty-three neonates with neoplasms were identified . There were 7 males (30%) and 16 females (70%) . Follow-up of survivors ranged from 4 months to 27 years (mean 9 years) . The 20 patients identified via the computerized registry system for 1980-1998 constitute 2% (20/925) of all neoplasms seen in patients </= 16 years of age over this same time period at DUMC . The histologic diagnoses were teratoma/germ cell tumor (n = 8, 35%), neuroblastoma (n = 5, 22%), retinoblastoma (n = 4, 17%), primary central nervous system (CNS) tumor (n = 3, 13%), and one case each of rhabdomyosarcoma, glossal glial choristoma, and hemangioma in the setting of Kasabach-Merritt Syndrome . Of the eight teratoma/germ cell tumor patients, 6 were female (75%) and 2 male (25%) . There was one malignant germ cell tumor, 2 immature teratomas, and 5 teratomas . Two of the seven patients with immature teratomas or teratoma were long-term survivors following surgery . The one patient with malignant germ cell tumor, treated with surgery and chemotherapy, died . Associated anomalies were imperforate anus, congenital absence of a limb, left ventricular hypertrophy, fusion or absence of toes, coarctation of the aorta, and pulmonary valve dysplasia . Of the five children with neuroblastoma, 4 were female . INSS Stages were 1 (n = 1), 2A (n = 1), 3 (n = 1), and 4S (n = 2) . Two were treated with surgery + chemotherapy + radiotherapy; two with surgery + chemotherapy; and one with surgery alone . Four children are long-term survivors . Associated congenital anomalies and medical problems were ventricular septal defect, seizure disorder, and Fanconi's anemia . A child with a dumbbell neuroblastoma, treated with surgery and chemotherapy, is paraplegic . Of the four children with retinoblastoma, two were female . Two had trilateral disease and two bilateral . Three of the four had a family history of retinoblastoma . The two children with trilateral retinoblastoma died after therapy with surgery, craniospinal and orbital irradiation, and chemotherapy . Two children with bilateral disease are long-term survivors: one treated with radiotherapy + chemotherapy and one with radiotherapy alone . They have marked orbital bone growth abnormalities . The three patients with CNS tumors were female . The histologies were glioblastoma multiforme, anaplastic astrocytoma, and malignant mixed oligodendroglioma . Two of the patients are long-term survivors after surgery + chemotherapy . Six children received eight courses of radiation therapy: 2 for Stage 4S neuroblastoma with respiratory compromise from an enlarging liver and 4 for retinoblastoma . The two infants with trilateral retinoblastoma received two courses of irradiation each: one of the treatment of intraocular tumor and a second, at an older age, for the pineal tumor . The most serious complication of anesthesia was a case of enterobacter cloacae sepsis in the central venous access line used for repetitively administering the anesthetic . CONCLUSION: The most common neonatal neoplasm histologic diagnoses are teratoma/germ cell tumor, neuroblastoma, and retinoblastoma . Neonatal neoplasms may be associated with congenital anomalies . Radiation therapy is administered infrequently in a population highly susceptible to late ill effects . When radiotherapy is required, anesthesia may be repetitively administered to aid in reproducible treatment.

J Am Vet Med Assoc, 2000 Apr 1, 216(7), 1096 - 9, 1074-5
Subcutaneous emphysema, pneumoperitoneum, and pneumoretroperitoneum after gastrostomy tube placement in a cat; Mason NJ et al.; A 17-year-old spayed female domestic shorthair cat developed subcutaneous emphysema, pneumoperitoneum, and pneumoretroperitoneum during endoscopic placement of a gastrostomy feeding tube after gastric insufflation and cannula insertion . The cat underwent exploratory laparotomy to investigate the possibility of gastric rupture but only a 2- to 3-mm defect was found in the gastric fundus at the site of cannula insertion . Pasteurella multocida and Enterobacter spp were cultured aerobically from the peritoneal cavity . The cat recovered without complications.

Can J Microbiol, 2000 Mar, 46(3), 278 - 82
Type I nitroreductases in soil enterobacteria reduce TNT (2,4,6,-trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine); Kitts CL et al.; Many enteric bacteria express a type I oxygen-insensitive nitroreductase, which reduces nitro groups on many different nitroaromatic compounds under aerobic conditions . Enzymatic reduction of nitramines was also documented in enteric bacteria under anaerobic conditions . This study indicates that nitramine reduction in enteric bacteria is carried out by the type I, or oxygen-insensitive nitroreductase, rather than a type II enzyme . The enteric bacterium Morganella morganii strain B2 with documented hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) nitroreductase activity, and Enterobacter cloacae strain 96-3 with documented 2,4,6-trinitrotoluene (TNT) nitroreductase activity, were used here to show that the explosives TNT and RDX were both reduced by a type I nitroreductase . Morganella morganii and E . cloacae exhibited RDX and TNT nitroreductase activities in whole cell assays . Type I nitroreductase, purified from E . cloacae, oxidized NADPH with TNT or RDX as substrate . When expression of the E . cloacae type I nitroreductase gene was induced in an Escherichia coli strain carrying a plasmid, a simultaneous increase in TNT and RDX nitroreductase activities was observed . In addition, neither TNT nor RDX nitroreductase activity was detected in nitrofurazone-resistant mutants of M . morganii . We conclude that a type I nitroreductase present in these two enteric bacteria was responsible for the nitroreduction of both types of explosive.

Clin Pharmacokinet, 2000 Mar, 38(3), 205 - 23
Clinical pharmacokinetics and pharmacodynamics of isepamicin; Tod M et al.; Isepamicin is an aminoglycoside antibacterial with properties similar to those of amikacin, but with better activity against strains producing type I 6'-acetyltransferase . The antibacterial spectrum includes Enterobacteriaceae and staphylococci . Anaerobes, Neisseriaceae and streptococci are resistant . The lower and upper break-points are 8 and 16 mg/L . Like other aminoglycosides, isepamicin exhibits a strong concentration-dependent bactericidal effect, a long post-antibiotic effect (several hours) and induces adaptive resistance . Isepamicin is administered intravenously or intramuscularly at a dosage of 15 mg/kg once daily or 7.5 mg/kg twice daily . Isepamicin is not bound to plasma proteins, and it distributes in extracellular fluids and into some cells (outer hair cells, kidney cortex) by active transport . Isepamicin is not metabolised and is eliminated solely via the renal route with an elimination half-life (t 1/2 beta) of 2 to 3 hours in adults with normal renal function . The clearance of isepamicin is reduced in neonates, and 7.5 mg/kg once daily is recommended in children <16 days old . Clearance is also reduced in the elderly, but no dosage adjustment is required . In patients with chronic renal impairment, isepamicin clearance is proportional to creatinine clearance (CLCR); the recommended regimen is 8 mg/kg with an administration interval of 24 hours in moderate impairment, 48 hours in severe impairment, 72 hours for CL(CR) 0.6 to 1.14 L/h (10 to 19 ml/min) and 96 hours for CL(CR) 0.36 to 0.54 L/h (6 to 9 ml/min) . In end-stage renal failure, isepamicin is eliminated by haemodialysis, but the administration interval should be determined by monitoring the plasma concentration . Compared with healthy volunteers, patients in the intensive care unit or with neutropenic cancer have an increased volume of distribution and a lower clearance, but the 15 mg/kg once daily regimen remains adequate . Isepamicin kinetics are linear in the range 7.5 to 25 mg/kg, so that dosage adjustments, if necessary, are straightforward . Isepamicin can induce nephro-, vestibulo- and oto-toxicity . However, animal and clinical studies show that isepamicin is one of the less toxic aminoglycosides . The usefulness of maintaining serum aminoglycoside concentrations within a therapeutic range remains controversial . With isepamicin, it is proposed to achieve a 1-hour concentration (30 minutes after a 30-minute infusion) >40 mg/L to maximise bactericidal efficacy, and a 'trough' concentration (at the end of the administration interval) <5 mg/L to minimise toxicity . These thresholds should be modified on an individual basis, considering covariates such as concomitant treatment, underlying disease, nature of bacterial strain and site of infection.

J Biol Chem, 2000 Jun 2, 275(22), 16851 - 6
New beta -lactamase inhibitory protein (BLIP-I) from Streptomyces exfoliatus SMF19 and its roles on the morphological differentiation; Kang SG et al.; A new beta-lactamase inhibitory protein (BLIP-I) from Streptomyces exfoliatus SMF19 was purified and characterized . The molecular mass of BLIP-I was estimated to be 17.5 kDa by gel filtration fast protein liquid chromatography . The N-terminal sequence was NH(2)-Asn-Ser-Gly-Phe-Ser-Ala-Glu-Lys-Tyr-Glu-Gln-Ile-Gln-Phe-Gly . BLIP-I inhibited Bacto(R) Penase (Difco), and plasmid encoded TEM-1 beta-lactamase, whereas it did not inhibit Enterobacter cloacae beta-lactamases . The K(i) value of BLIP-I against TEM-1 beta-lactamase was determined to be 0.047 nm . The gene (bliA) encoding BLIP-I protein was identified by screening a genomic library using an oligonucleotide probe with a sequence based on the N-terminal sequence of BLIP-I . Analysis of the nucleotide sequence revealed that the gene was 558 base pairs in length and encoded a mature protein of 157 amino acid residues preceded by a 29-amino acid signal sequence . Pairwise comparison of the deduced amino acid sequence showed 38% identity with BLIP of Streptomyces clavuligerus . Furthermore, the 49th amino acid residue of BLIP-I was identical to Asp-49 of BLIP that was characterized to be an important residue for the inhibitory activity of BLIP . A modified BLIP-I in which Asp-49 was replaced by alanine (D49A) was obtained by site-directed mutagenesis . The inhibitory activities of recombinant (r) BLIP-I and its D49A mutant derivative, expressed in Escherichia coli, were compared . The K(i) value of rBLIP-I against TEM-1 beta-lactamase was similar to that of wild-type BLIP-I, but the D49A mutation increased the K(i) of rBLIP-I inhibition approximately 200-fold . A disruption mutant of the bliA gene in S . exfoliatus SMF19 was obtained by replacing the wild-type bliA gene with a copy inactivated by inserting a hygromycin resistance gene . The disruption mutant showed a bald phenotype, indicating that the bliA gene plays a role in morphological differentiation.

J Antimicrob Chemother, 2000 Apr, 45(4), 537 - 9
Clinical relevance of Proteus mirabilis in hospital patients: a two year survey; de Champs C et al.; A retrospective study was performed on 1072 non-duplicate isolates of Proteus mirabilis, taken in the period April 1996 to March 1998, and on 100 patient charts randomly selected during the same period . P . mirabilis isolates accounted for 7.7% of Enterobacteriaceae . The isolates were predominantly from urine (70.2%); of the total, 38.0% were penicillinase-producing isolates, 6.9% were extended-spectrum beta-lactamase (ESBL)-producing isolates and 3.6% produced inhibitor-resistant beta-lactamase (IRB) . ESBL-producing isolates were observed in long-stay and intensive care and IRB-producing isolates in paediatric units . Of the 95 patients whose charts were examined, 69 had a confirmed infection, which in 42 cases was nosocomial.

J Clin Microbiol, 2000 Apr, 38(4), 1339 - 46
Evaluation of the Wider system, a new computer-assisted image-processing device for bacterial identification and susceptibility testing; Canton R et al.; The Wider system is a newly developed computer-assisted image-processing device for both bacterial identification and antimicrobial susceptibility testing . It has been adapted to be able to read and interpret commercial MicroScan panels . Two hundred forty-four fresh consecutive clinical isolates (138 isolates of the family Enterobacteriaceae, 25 nonfermentative gram-negative rods {NFGNRs}, and 81 gram-positive cocci) were tested . In addition, 100 enterobacterial strains with known beta-lactam resistance mechanisms (22 strains with chromosomal AmpC beta-lactamase, 8 strains with chromosomal class A beta-lactamase, 21 broad-spectrum and IRT beta-lactamase-producing strains, 41 extended-spectrum beta-lactamase-producing strains, and 8 permeability mutants) were tested . API galleries and National Committee for Clinical Laboratory Standards (NCCLS) microdilution methods were used as reference methods . The Wider system correctly identified 97.5% of the clinical isolates at the species level . Overall essential agreement (+/-1 log(2) dilution for 3,719 organism-antimicrobial drug combinations) was 95.6% (isolates of the family Enterobacteriaceae, 96.6%; NFGNRs, 88.0%; gram-positive cocci, 95.6%) . The lowest essential agreement was observed with Enterobacteriaceae versus imipenem (84.0%), NFGNR versus piperacillin (88.0%) and cefepime (88.0%), and gram-positive isolates versus penicillin (80.4%) . The category error rate (NCCLS criteria) was 4.2% (2.0% very major errors, 0.6% major errors, and 1 . 5% minor errors) . Essential agreement and interpretive error rates for eight beta-lactam antibiotics against isolates of the family Enterobacteriaceae with known beta-lactam resistance mechanisms were 94.8 and 5.4%, respectively . Interestingly, the very major error rate was only 0.8% . Minor errors (3.6%) were mainly observed with amoxicillin-clavulanate and cefepime against extended-spectrum beta-lactamase-producing isolates . The Wider system is a new reliable tool which applies the image-processing technology to the reading of commercial trays for both bacterial identification and susceptibility testing.

Eur J Clin Microbiol Infect Dis, 2000 Feb, 19(2), 112 - 7
Antibiotic susceptibility of bacterial strains isolated from patients with community-acquired urinary tract infections in France . Multicentre Study Group; Goldstein FW; The aim of this study was to determine the distribution and antibiotic susceptibility patterns of bacterial strains isolated from adults with community-acquired urinary tract infections (UTI) in France . From December 1996 to March 1997, each of 15 private laboratories in France consecutively collected about 80 non-duplicate strains isolated from adult outpatients with UTI, including patients receiving care at home, and tested their susceptibility by the disk diffusion test . A total of 1160 strains were collected: 1031 gram-negative bacilli, including Escherichia coli (n = 865), Proteus mirabilis (n = 68) and Klebsiella spp . (n = 40), and 129 gram-positive cocci, including Staphylococcus aureus (n = 16), other staphylococci (n = 25), group B streptococci (n = 25) and enterococci (n = 63) . In the case of 430 bacterial isolates, the patients had either been hospitalised in the last 6 months or received antibiotic treatment in the last 3 months . The antibiotic susceptibility rates for Escherichia coli were: amoxicillin (58.7%), amoxicillin-clavulanic acid (63.3%), ticarcillin (61.4%), cephalothin (66.8%) cefuroxime (77.6%), cefixime (83.6%), cefotaxime (99.8%), ceftazidime (99%), nalidixic acid (91.9%), norfloxacin (96.6%), ofloxacin (96.3%), ciprofloxacin (98.3%), cotrimoxazole (78.2%), fosfomycin (99.1%) and gentamicin (98.4%) . Of the Enterobacteriaceae, five strains produced an extended-spectrum beta-lactamase . Methicillin resistance was detected in nine Staphylococcus aureus isolates . The most important findings were two extended-spectrum, beta-lactamase-producing and three methicillin-resistant Staphylococcus aureus strains isolated from patients who had not been hospitalised in the last 6 months or taken antibiotics in the last 3 months . The findings indicate that these strains can spread within the community; therefore, monitoring antibiotic susceptibility of bacteria isolated in the community appears to be mandatory.

Wiad Lek, 1999, 52(11-12), 554 - 8
{The occurrence of the Enterobacter genus rods in the clinical materials and materials taken from hospital environment}; Janicka G et al.; Due to continuously existing essential meaning of strains of Enterobacter spp . in human infections we investigated the occurrence of Enterobacter spp . in different clinical materials and in materials taken from hospital environment . Amongst 26,025 materials taken from patients there were 249 (1.0%) Enterobacter strains and respectively amongst 954 environmental materials--there were 11 (1.2%) Enterobacter spp . In isolated Enterobacter strains the percentage occurrence was: hospital materials: E . cloacae--65.6%, E . agglomerans--12.1%, E . aerogenes--6.25%, E . sakazakii--5.4%, E . gergoviae--1.3%, E . amnigenus--0.9%, E . intermedius--0.9% and Enterobacter spp.--7.6%; outpatient materials: E . cloacae--72.0%, E . sakazakii--12.0%, E . agglomerans--8.0%, E . aerogenes--4.0% and E . amnigenus--4.0%; hospital community: E . cloacae--63.6%, E . agglomerans--18.2% and E . sakazakii--18.2%.

Diagn Microbiol Infect Dis, 2000 Jan, 36(1), 53 - 6
High incidence of Klebsiella pneumoniae clinical isolates to extended-spectrum B-lactam drugs in intensive care units; Shehabi AA et al.; A prospective study conducted among Jordanian ICU patients in 1997 using Etest identified resistance rates among isolates of E . coli (25%-44%), Enterobacter spp . (54%-62%), and Klebsiella spp . (30%-80%) to extended-spectrum B-lactams (ESBLs): ceftazidime, cefotaxime, ceftriaxone, and aztreonam . All these isolates were susceptible to imipenem and showed low resistance rate to ciprofloxacin (5%-19%) and amikacin (13%-18%) . Higher and significant resistance rates of Klebsiella isolates to ceftazidime (80%) and aztreonam (65%) were observed in 1997 compared with a previous study performed in 1994 . The majority of Klebsiella pneumoniae (70%) express different ESBL phenotypes that were almost resistant to aztreonam and ceftazidime but susceptible or resistant to cefotaxime and/or ceftriaxone . This prospective study strongly suggests that ESBL production of Klebsiella pneumoniae isolates have been highly disseminated among ICU patients during 1997.

Rev Inst Med Trop Sao Paulo, 2000 Jan-Feb, 42(1), 1 - 7
Molecular epidemiology of a nosocomial outbreak due to Enterobacter cloacae and Enterobacter agglomerans in Campinas, São Paulo, Brazil; Goncalves CR et al.; A total of 73 isolates (57 Enterobacter cloacae and 16 Enterobacter agglomerans), recovered during an outbreak of bacteremia in the Campinas area, Sao Paulo, Brazil, were studied . Of these isolates, 61 were from parenteral nutrition solutions, 9 from blood cultures, 2 from a sealed bottle of parenteral nutrition solution, and one was of unknown origin . Of the 57 E . cloacae isolates, 54 were biotype 26, two were biotype 66 and one was non-typable . Of 39 E . cloacae isolates submitted to ribotyping, 87.2% showed the same banding pattern after cleavage with EcoRI and BamHI . No important differences were observed in the antimicrobial susceptibility patterns among E . cloacae isolates exhibiting the same biotype, serotype and ribotype . All E . agglomerans isolates, irrespective of their origin, showed same patterns when cleaved with EcoRI and BamHI . The results of this investigation suggest an intrinsic contamination of parenteral nutrition solutions and incriminate these products as a vehicle of infection in this outbreak.

J Nutr Biochem, 2000 Mar, 11(3), 147 - 52
Digestion of plant monogalactosyldiacylglycerol and digalactosyldiacylglycerol in rat alimentary canal(1); Sugawara T et al.; We investigated digestion of orally fed galactoglycerolipids such as monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) from wheat flour in the rat alimentary canal, especially focusing on the digestive fates of deacylated galactosylglycerol structures . After a single oral administration of MGDG (20 mg/rat), monogalactosylmonoacylglycerol and monogalactosylglycerol (MGG) were found to be major digestion products in the intestinal tract . Similarly, digalactosylmonoacylglycerol and digalactosylglycerol (DGG) were confirmed to be present in the intestinal tract after DGDG ingestion (20 mg/rat) . In rats fed wheat flour glycolipids (42 mg MGDG and 81 mg DGDG per rat), completely deacylated galactosylglycerols (MGG and DGG) were not detected in portal plasma . Although the deacylated galactosylglycerols were not significantly decomposed by intestinal mucosa in vitro, they were hydrolyzed by cecal contents . The results demonstrated that orally ingested plant galactoglycerolipids in the rat alimentary canal are rapidly hydrolyzed into constituent fatty acids and that hydrophilic galactosylglycerols and the hydrophilic backbone galactosylglycerols are not absorbed from intestine or degraded into galactose and glycerol in the intestinal tract . Therefore, the presence of deacylated galactosylglycerols may affect the fermentative activity of enterobacteria in the cecum and colon.

Clin Pharmacol Ther, 2000 Mar, 67(3), 229 - 36
Target site concentrations after continuous infusion and bolus injection of cefpirome to healthy volunteers; Hollenstein U et al.; BACKGROUND: Recent data indicate a higher level of effectivity of beta-lactam antibiotics if serum concentrations are kept above the minimal inhibitory concentration (MIC) of the pathogen . This concept would favor continuous infusion over bolus dosing . However, it is usually not the serum concentration but the free interstitial concentration in the target tissue that determines antibiotic activity . We therefore set out to measure effective drug concentrations in the interstitial space of muscle and subcutaneous adipose tissue and to compare trough levels and times above the MIC after bolus versus continuous infusion of cefpirome . METHODS: Twelve healthy volunteers received a single dose of 2 g cefpirome as an intravenous bolus or as a continuous infusion over 8 hours in a crossover design, and the resulting free interstitial tissue concentrations were measured with use of microdialysis . RESULTS: After bolus injection, mean interstitial trough concentrations were 3.0 +/- 1.9 microg/mL and 2.1 +/-1.0 microg/mL for muscle and subcutaneous tissue, respectively; continuous infusion resulted in trough levels of 10.1 +/- 6.8 microg/mL and 10.1 +/- 4.6 microg/mL for muscle and subcutaneous tissue, respectively . This resulted in significantly longer times above the MIC with continuous infusion for Staphylococcus epidermidis and Enterobacter cloacae . Bacteria with an MIC < or =1 would be covered by either method, whereas higher doses seem to be necessary for Pseudomonas aeruginosa . CONCLUSION: Although susceptible organisms will usually be covered sufficiently with standard dosing regimens, soft tissue infections with bacteria that have MIC values of 2 to 8 may profit from continuous application . Coverage of P aeruginosa, however, would be inadequate with conventional daily doses of 4 g cefpirome regardless of the method of application.

Drug Saf, 2000 Mar, 22(3), 191 - 4
Carbapenems in serious infections: a risk-benefit assessment; Norrby SR; The tolerability of the 2 most frequently used carbapenems, imipenem/cilastatin and meropenem, is reviewed . Both of these drugs, but especially imipenem, are potentially neurotoxic and may cause seizures if overdosed relative to renal function and/or bodyweight . The therapeutic margin is considerably narrower with imipenem/cilastatin which cannot be given at doses required for treatment of bacterial meningitis . Meropenem on the other hand, is considerably less prone to cause seizures and its tolerability and efficacy are well documented in 3 relatively large, controlled studies in adults and children with meningitis . They showed that meropenem was as effective and well tolerated as cefotaxime or ceftriaxone . Another potential advantage of meropenem over imipenem/cilastatin is that it can be given intravenously at a high rate without increased risk of nausea or vomiting . An obvious reason for using a carbapenem instead of a cephalosporin for empirical treatment of life-threatening infections is that both imipenem/cilastatin and meropenem have a broader spectrum of activity . They are also more resistant to hydrolysis by the most common beta-lactamases, including the class I cephalosporinase frequently produced by Enterobacter spp . and Pseudomonas spp . and the extended spectrum enzymes, now commonly found in Escherichia coli and Klebsiella spp.

Int J Infect Dis, 2000, 4(2), 75 - 84
Two-year assessment of the pathogen frequency and antimicrobial resistance patterns among organisms isolated from skin and soft tissue infections in Latin American hospitals: results from the SENTRY antimicrobial surveillance program, 1997-98 . SENTRY Study Group; Gales AC et al.; OBJECTIVES: This study was conducted to evaluate the frequency of occurrence and antimicrobial susceptibility of bacterial isolates collected from patients with skin and soft tissue infections (SSTI) in Latin American hospitals, as part of the SENTRY Antimicrobial Surveillance Program . The dissemination of multidrug-resistant methicillin-resistant Staphylococcus aureus (MDR-MRSA) among the Latin American countries also was studied . MATERIAL AND METHODS: A total of 885 bacterial isolates were analyzed . At the monitoring laboratory, antimicrobial susceptibility testing utilizing the reference broth microdilution method and confirmation of species identification were performed . Enterobacteriaceae possibly producing extended-spectrum beta-lactamases (ESBL) and MDR-MRSA isolates were genotyped by ribotyping using the RiboPrinter and by pulsed-field gel electrophoresis . RESULTS: Staphylococcus aureus (31%) was the most common etiologic agent causing SSTI, followed by Escherichia coli (13.4%) and Pseudomonas aeruginosa (11%) . Thirty-one percent of S . aureus isolates were resistant to oxacillin (methicillin) . The presence of ESBL phenotypes was markedly higher among the Klebsiella pneumoniae (35.5%) than E . coli isolates (10 . 2%) . Meropenem was the compound with the highest susceptibility rate among the Enterobacteriaceae (100%) and P . aeruginosa (95%) isolates . A great genetic similarity was observed among the MDR-MRSA in Latin America . CONCLUSION: High resistance rates to antimicrobial drugs among the most frequent bacterial pathogens were observed in 10 medical centers in Latin America . This study also demonstrated a clonal dissemination of a MDR-MRSA strain in several nations.

Arch Intern Med, 2000 Mar 27, 160(6), 797 - 805
Emphysematous pyelonephritis: clinicoradiological classification, management, prognosis, and pathogenesis; Huang JJ et al.; BACKGROUND: Emphysematous pyelonephritis (EPN) is a rare, severe gas-forming infection of renal parenchyma and its surrounding areas . The radiological classification and adequate therapeutic regimen are controversial and the prognostic factors and pathogenesis remain uncertain . OBJECTIVES: To elucidate the clinical features, radiological classification, and prognostic factors of EPN; to compare the modalities of management (ie, antibiotic treatment alone, percutaneous catheter drainage combined with antibiotic treatment, or nephrectomy) and outcome among the various radiological classes of EPN; and to clarify the gas-forming mechanism and pathogenesis of EPN by gas analysis and pathological findings . PATIENTS AND METHODS: Forty-eight EPN cases from our institution were enrolled between August 1,1989, and November 30, 1997 . According to the radiological findings on computed tomographic scan, they were classified into the following classes: (1) class 1: gas in the collecting system only; (2) class 2: gas in the renal parenchyma without extension to extrarenal space; (3) class 3A: extension of gas or abscess to perinephric space; class 3B: extension of gas or abscess to pararenal space; and (4) class 4: bilateral EPN or solitary kidney with EPN . The clinical manifestations, management, and outcome were compared . The gas contents of specimens from 6 patients were analyzed . The pathological findings from 8 patients who received nephrectomy were reviewed . The statistical methods consisted of the Fisher exact test (2 tailed) for categorical variables and Wilcoxon rank sum test for continuous variables to test the predictors of poor prognosis . RESULTS: Forty-six patients (96%) had diabetes mellitus, and 10 (22%) of the 46 also had urinary tract obstruction in the corresponding renoureteral unit . The other 2 nondiabetic patients (4%) had severe hydronephrosis . Twenty-one (72%) of the 29 patients with diabetes mellitus also had a glycosylated hemoglobin A(1c) level higher than 0.08 . Escherichia coli (69%) and Klebsiella pneumoniae (29%) were the most common pathogens . The mortality rate in patients who received antibiotic treatment alone was 40% (2 of 5 patients) . The success rate of management by percutaneous catheter drainage (PCD) combined with antibiotic treatment was 66% (27 of 41 patients) . In classes 1 and 2 EPN, all the patients who were treated using a PCD or ureteral catheter combined with antibiotic treatment survived . In extensive EPN (classes 3 and 4), 17 (85%) of the 20 patients with fewer than 2 risk factors (ie, thrombocytopenia, acute renal function impairment, disturbance of consciousness, or shock) were successfully treated using PCD combined with antibiotic treatment; and the patients with 2 or more risk factors had a significantly higher failure rate than those with no or only 1 risk factors (92% vs 15%, P<.001) . Eight of the 14 patients who had an unsuccessful treatment using a PCD underwent subsequent nephrectomy, 7 of whom survived . Only 2 patients were managed by direct nephrectomy and survived . The overall success rate of nephrectomy was 90% (9 of 10 patients) . The total mortality was 18.8% (9 of 48 patients) . Five of the 6 gas samples contained hydrogen (average, 12.8%), and all had carbon dioxide (average, 14.4%) . The pathological findings from 8 of 10 who underwent nephrectomy revealed poor perfusion in most cases (ie, infarction, 5 patients; vascular thrombosis, 3 patients; and arteriosclerosis and/or glomerulosclerosis, 4 patients) . CONCLUSION: Acute renal infection with E coli or K pneumoniae in patients with diabetes mellitus and/or urinary tract obstruction is the cornerstone for the development of EPN . Mixed acid fermentation of glucose by Enterobacteriaceae is the major pathway of gas formation . For localized EPN (classes 1 and 2), PCD combined with antibiotic treatment can provide a good outcome . (ABSTRACT TRUNCATED)

Poult Sci, 2000 Feb, 79(2), 212 - 8
Physical, chemical, and microbiological changes in the crop of broiler chickens subjected to incremental feed withdrawal; Hinton A Jr et al.; Trials were conducted to determine the effect of feed withdrawal on the weight, pH, native bacterial flora, and Salmonella typhimurium persistence in crops of broilers . Six-week-old broilers were provided medicated or unmedicated feed and were subjected to feed withdrawal for 0 to 24 h in transportation crates or on litter . After feed withdrawal, broilers were stunned, bled, scalded, and picked . Crops were aseptically removed and weighed . Crops were then blended in 20 mL distilled water, and pH values of the suspensions were measured . Aerobic bacteria, Enterobacteriaceae, S . typhimurium, and lactic acid bacteria in the suspension were enumerated on appropriate bacteriological media . Feed withdrawal produced significant decreases in the crop weights . Crop pH increased by 1.0 unit within 6 h of feed withdrawal . Enterobacteriaceae and S . typhimurium populations generally decreased during the first 12 h of feed withdrawal and remained unchanged or increased during the final 12 h of the 24-h feed withdrawal period . The number of lactic acid bacteria recovered from the crop usually decreased as the duration of feed withdrawal increased . Changes in crop weights, pH, native microflora, or the recovery of S . typhimurium from the crop were similar in broilers subjected to feed withdrawal on litter or in crates and in broilers provided medicated or unmedicated feed before initiating feed withdrawal . Findings indicate that a decrease in the number of lactic acid producing bacteria in the crop and an increase in crop pH may be related to the reduction of anti-Enterobacteriaceae activity in the crop during extended feed withdrawal.

J Appl Microbiol, 2000 Jan, 88(1), 90 - 7
Biological control of an insect pest by gut-colonizing Enterobacter cloacae transformed with ice nucleation gene; Watanabe K et al.; The ice nucleation (IN) gene inaA of epiphytic Erwinia (Pantoea) ananas IN10 was transformed into Enterobacter cloacae WBMH-3-CMr originated from the faeces of silkworms . The transformant designated as Ent . cloacae WBMH-3-CMr(pICE6S13) exhibited IN activity, unlike the parent strain . The transgenic strain was ingested by mulberry pyralid larvae, fed on detached mulberry leaves, and the supercooling capacity and cold hardiness of these larvae were examined . The mean supercooling point (SCP) of the larvae ingesting the transgenic strain was - 3.3 degrees C, 8 degrees C higher than that of larvae treated with distilled water (control) and 1.5 C higher than an ice nucleation active (INA) strain of Erw . ananas . The SCPs of the larvae were stably maintained over the 9 d after ingestion . The maintenance of these high SCPs was due to transgenic Ent . cloacae having a more stable and efficient gut colonization than Erw . ananas, which is identified by the distribution of a narrower range of SCPs (-2 to -5 degrees C) in larvae treated with the transgenic stain . Furthermore, most of the larvae ingesting the transgenic strain froze and died when they were exposed to cold conditions of -5 degrees C for 18 h, 3 or 7 d after ingestion . In contrast, most of the larvae ingesting no bacterium did not die under similar conditions . On the other hand, the growth ability of Ent . cloacae WBMH-3-CMr on mulberry leaves tended to be lower than that of epiphytic Erw . ananas, as assayed by pot tests . These findings would expand the possibility of biological control using INA bacteria since Ent . cloacae would harbour a broader host (insect) range for gut colonization and a smaller affinity to plants to benefit from prevention of plant frost injury.

East Afr Med J, 1999 Oct, 76(10), 587 - 9
Quinolones for short-term treatment of uncomplicated urinary tract infection; Kadiri S et al.; OBJECTIVE: To investigate whether quinolones produce in vivo responses comparable to reported in vitro activity against the spectrum of organisms in uncomplicated urinary tract infection (UTI) in Nigeria . DESIGN: Equal numbers of patients with urine culture positive UTI were randomized to oral quinolone, perfloxacin 400 mg bd twice a day and ofloxacin 200 mg bd twice a day for five days . SETTING: Out-patient clinics and wards at the University College Hospital, Ibadan . SUBJECTS: Sixty patients aged sixteen years and above with uncomplicated UTI . MAIN OUTCOME MEASURES: Number of isolates, number of patients with clinical and bacteriological cure one week after commencing therapy . Relative effectiveness and side effects of the drugs . RESULTS: Sixty- four bacterial isolates were obtained with the enterobacteriaceae comprising 86% . Sixty-two (97%) were sensitive to both drugs in vitro . Clinical cure occurred in 57 patients (95%), being 28 (93%) in those taking perfloxacin and 29 (97%) in those taking ofloxacin . Bacteriological cure occurred in 55 patients (92%), being 27 (90%) in those taking perfloxacin and 28 (93%) in those taking ofloxacin . Fifty-nine of the 64 isolates (92%) were eliminated in one week, 30 of 33 (91%) in those taking perfloxacin, and 29 of 31 (94%) in those taking ofloxacin; the difference was insignificant (p = 1.16) . The enterobacteriaceae were generally susceptible to both drugs . Side effects were minor and infrequent . CONCLUSION: Quinolones were highly active against the common urinary pathogens in these Nigerian patients and can be reliably employed in treatment when culture results are unavailable.

Diagn Microbiol Infect Dis, 2000 Mar, 36(3), 185 - 91
In-vitro activity of FK 037 (Cefoselis), a novel 4(th) generation cephalosporin, compared to cefepime and cefpirome on nosocomial staphylococci and gram-negative isolates; Giamarellos-Bourboulis EJ et al.; The novel 4(th) generation cephalosporin FK037 was in vitro compared to cefepime and cefpirome on 563 multiresistant nosocomial isolates including methicillin-susceptible (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) . Their time-kill effect was studied on MSSA, Escherichia coli, Klebsiella pneumoniae, and isolates of Enterobacter cross-resistant to cefotaxime, ceftriaxone, and to ceftazidime, their interaction with amikacin being also evaluated on the latter isolates . Results revealed that FK037 possessed a superior antistaphylococcal activity on MSSA isolates to both other compounds being however equal active to cefepime and cefpirome on multiresistant enterobacteriaceae . Synergy was documented between 4(th) generation cephalosporins and amikacin on K . pneumoniae and on Enterobacter spp . cross-resistant to 3(rd) generation cephalosporins . In the latter species 4(th) generation cephalosporins remained inactive . The presented results support the need of clinical studies with FK037 as monotherapy for nosocomial infections based on the local surveillance data of the level of antimicrobial resistance of each hospital.

Int J Food Microbiol, 1999 Feb 2, 46(2), 123 - 34
Using an electronic nose for determining the spoilage of vacuum-packaged beef; Blixt Y et al.; The use of an electronic nose in the quantitative determination of the degree of spoilage of vacuum-packaged beef was evaluated . Beef from four different slaughterhouses was sliced, vacuum-packaged and stored at 4 degrees C for 8 weeks . Samples were withdrawn for bacterial (aerobic bacteria, lactic acid bacteria, Brochothrix thermosphacta, Pseudomonas and Enterobacteriaceae) and sensorial analyses and analysis of the volatile compounds during the storage period . A trained panel was used for the sensorial evaluations . The volatile compounds were analysed using an electronic nose containing a sensory array composed of 10 metal oxide semiconductor field-effect transistors, four Tagushi type sensors and one CO2-sensitive sensor . Four of the 15 sensors were excluded due to lack of response or overloading . Partial least-squares regression was used to define the mathematical relationships between the degree of spoilage of vacuum-packaged beef, as determined by the sensory panel, and the signal magnitudes of the sensors of the electronic nose . The mathematical models were validated after 6 months using a new set of samples . The stability of the sensors during this period was examined and it was shown that the sensitivity of five of the 11 sensors used had changed . Using the six remaining sensors, the signal patterns obtained from the meat from the different slaughterhouses did not change over a period of 6 months . It was shown that the degree of spoilage, as calculated using a model based on two Tagushi sensors, correlated well with the degree of spoilage determined by the sensory panel (r2 = 0.94).

Lett Appl Microbiol, 2000 Jan, 30(1), 61 - 6
Microbial populations and volatile compounds in the 'bone taint' spoilage of dry cured ham; Garcia C et al.; 'Bone taint' is one of the most important causes of spoilage of dry cured ham . This alteration is characterized by a foul-smelling odour . The microbial population and volatile compounds associated with incipient 'bone taint' were evaluated . Enterobacteriaceae species were found at levels of 7.94 x 10(5) cfu g(-1) in spoiled hams and were not detected in unspoiled hams . Serratia sp . and Proteus sp . are the main organisms characterized . The volatile compounds from the spoiled hams give rise to higher levels of ketones, alcohols and esters than unspoiled hams, that could be originated by microbial metabolism of the above bacteria . Thus, volatile and Enterobacteriaceae analyses should be used to determine this incipient spoilage in the meat industry.

Eur J Biochem, 2000 Apr, 267(7), 2008 - 13
Biological activities of lipopolysaccharides are determined by the shape of their lipid A portion; Schromm AB et al.; Lipopolysaccharide (LPS) represents a major virulence factor of Gram-negative bacteria ('endotoxin') that can cause septic shock in mammals including man . The lipid anchor of LPS to the outer membrane, lipid A, has a peculiar chemical structure, harbours the 'endotoxic principle' of LPS and is responsible for the expression of pathophysiological effects . Chemically modified lipid A can be endotoxically inactive, but may express strong antagonistic activity against LPS, a property that can be utilized in antisepsis treatment . We show here that these different biological activities are directly correlated with the molecular shape of lipid A . Only (hexaacyl) lipid A with a conical/concave shape, the cross-section of the hydrophobic region being larger than that of the hydrophilic region, exhibited strong interleukin-6 (IL-6)-inducing capacity . Most strikingly, a correlation between a cylindrical molecular shape of lipid A and antagonistic activity was established: IL-6 induction by enterobacterial LPS was inhibited by cylindrically shaped lipid A except for compounds with reduced headgroup charge . The antagonistic action is interpreted by assuming that lipid A molecules intercalate into the cytoplasmic membrane of mononuclear cells, and subsequently blocking of the putative signaling protein by the lipid A with cylindrical shape.

Int J Antimicrob Agents, 2000 Jan, 13(3), 197 - 201
Antimicrobial and antioxidant activities of Feijoa sellowiana fruit; Vuotto ML et al.; The present study was designed to evaluate the antibacterial and antioxidant activities of an aqueous extract from the tropical Feijoa sellowiana Berg . fruit which is widely used for human food . The extract was tested against gram-positive and gram-negative bacteria by a broth dilution test and on human whole blood leukocytes, as well as isolated neutrophils using a chemiluminescence (CL) assay . The extract inhibited bacterial growth; Pseudomonas aeruginosa, Enterobacter aerogenes and Enterobacter cloacae were the most sensitive . The fruit extract significantly decreased CL emission from human whole blood phagocytes and isolated polymorphonuclear leukocytes whether they were activated or not by soluble or phagocytic stimuli . F . sellowiana showed both antibacterial and antioxidant properties and therefore its extract might be used as a new multifaceted drug.

Presse Med, 2000 Feb 26, 29(7), 393 - 5
{Skin and osteoarticular infections of the diabetic foot . Role of infection}; Boutoille D et al.; A MAJOR PROBLEM: Two-thirds of all amputations involve infection . Infection is favored by dysfunction of the antibacterial defense systems due to high blood glucose and vascular disorders . DIAGNOSIS: General signs of infection are usually not found . A careful exploration is required to rule out or confirm osteitis in order to guide surgery and plan the antibiotic regimen . A history of chronic and/or recurrent ulceration or direct signs at inspection may be suggestive of osteitis . Radiographic signs are late and nonspecific . Scintigraphy scans are difficult to interpret . Magnetic resonance imaging can be quite helpful in difficult cases . BACTERIOLOGICAL PROOF: Staphylococcus aureus and to a lesser extent streptococci account for almost all of the superficial infections in the diabetic foot . In case of deep ulceration, it is important to obtain deep specimens at surgical cleansing as more superficial samples are easily contaminated . Nevertheless, if Staphylococcus aureus is isolated from pus coming from a deep zone fistulizing to the skin, it is likely the causal agent since 80% of all bone infections involve S . aureus . Other germs besides staphylococci and streptococci include enterobacteria (40%), enterococci (26%) and pseudomonas (7%) . Several germs are involved in about 70% of cases with a probable synergetic effect between the different bacterial colonies within the infected tissues.

Antimicrob Agents Chemother, 2000 Apr, 44(4), 1102 - 7
In vitro activities of sitafloxacin (DU-6859a) and six other fluoroquinolones against 8,796 clinical bacterial isolates; Milatovic D et al.; The in vitro activities of sitafloxacin, ciprofloxacin, trovafloxacin, levofloxacin, clinafloxacin, gatifloxacin, and moxifloxacin against 5,046 gram-negative bacteria, 3,344 gram-positive cocci, and 406 anaerobes were determined . Sitafloxacin was the most active agent against gram-positive cocci and anaerobes . Against Enterobacteriaceae and nonfermenters, its activity was either equivalent to or better than that of clinafloxacin.

Antimicrob Agents Chemother, 2000 Apr, 44(4), 885 - 90
Efficacies of imipenem, meropenem, cefepime, and ceftazidime in rats with experimental pneumonia due to a carbapenem-hydrolyzing beta-lactamase-producing strain of Enterobacter cloacae; Mimoz O et al.; The antibacterial activities of imipenem-cilastatin, meropenem-cilastatin, cefepime and ceftazidime against Enterobacter cloacae NOR-1, which produces the carbapenem-hydrolyzing beta-lactamase NmcA and a cephalosporinase, and against one of its in vitro-obtained ceftazidime-resistant mutant were compared by using an experimental model of pneumonia with immunocompetent rats . The MICs of the beta-lactams with an inoculum of 5 log(10) CFU/ml were as follows for E . cloacae NOR-1 and its ceftazidime-resistant mutant, respectively: imipenem, 16 and 128 microg/ml, meropenem, 4 and 32 microg/ml, cefepime, <0.03 and 1 microg/ml, and ceftazidime, 1 and 512 microg/ml . The chromosomally located cephalosporinase and carbapenem-hydrolyzing beta-lactamase NmcA were inducible by cefoxitin and meropenem in E . cloacae NOR-1, and both were stably overproduced in the ceftazidime-resistant mutant . Renal impairment was induced (uranyl nitrate, 1 mg/kg of body weight) in rats to simulate the human pharmacokinetic parameters for the beta-lactams studied . Animals were intratracheally inoculated with 8.5 log(10) CFU of E . cloacae, and therapy was initiated 3 h later . At that time, animal lungs showed bilateral pneumonia containing more than 6 log(10) CFU of E . cloacae per g of tissue . Despite the relative low MIC of meropenem for E . cloacae NOR-1, the carbapenem-treated rats had no decrease in bacterial counts in their lungs 60 h after therapy onset compared to the counts for the controls, regardless of whether E . cloacae NOR-1 or its ceftazidime-resistant mutant was inoculated . A significant decrease in bacterial titers was observed for the ceftazidime-treated rats infected with E . cloacae NOR-1 only . Cefepime was the only beta-lactam tested effective as treatment against infections due to E . cloacae NOR-1 or its ceftazidime-resistant mutant.

Int J Antimicrob Agents, 2000 Mar, 14(2), 161 - 4
Antimicrobial susceptibility patterns of bacteria at the Makassed General Hospital in Lebanon; Shaar TJ et al.; Bacterial resistance to various antimicrobial agents is most common in areas with high usage of antibiotics such as in countries where over-the-counter availability promotes usage . In Lebanon, information about bacterial resistance to antimicrobial agents is limited . In this study, data on the antimicrobial susceptibility patterns have been collected for the last 7 years in addition to the first 6 months of 1996 at the Makassed General Hospital in Lebanon . Enterobacteriaceae and Pseudomonas species proved to have high but variable rates of multidrug resistance . Among Staphylococcus aureus isolates, 17% were resistant to methicillin . A high percentage of resistance to penicillin (76-88%) was noted among Streptococcus pneumoniae . These resistance patterns were generally comparable with those of other medical centres.

Int J Antimicrob Agents, 2000 Mar, 14(2), 137 - 42
CTX-M-type beta-lactamases: an emerging group of extended-spectrum enzymes; Tzouvelekis LS et al.; CTX-M-type beta-lactamases constitute a novel group of class A beta-lactamases with extended-spectrum properties . They are encoded by transferable plasmids and found in various enterobacteria, mostly Salmonella typhimurium, Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis . CTX-M enzymes share extensive sequence similarity with the chromosomal beta-lactamases of Klebsiella oxytoca . They efficiently hydrolyze many newer broad-spectrum oximino-beta-lactams including cefotaxime, ceftriaxone and aztreonam and are readily inhibited by tazobactam and clavulanate . CTX-M-producing enterobacteria are endemic in Latin America and in some areas of North Eastern Europe . Data on their structure, properties and epidemiology are discussed.

J Chemother, 1999 Dec, 11(6), 486 - 93
Fourth generation cephalosporins in the antimicrobial chemotherapy of surgical infections; Giamarellou H; Surgical infections include a variety of entities such as secondary peritonitis, intra-abdominal abscesses, obstetric and gynecological infections as well as bone-joint and soft-tissue infections . By definition the term "surgical infection" implies that surgery itself plays the major role in therapy, while antimicrobial chemotherapy is only supplementary . Broad-spectrum empirical regimens employed include the combination of a 1st or 2nd generation cephalosporin plus clindamycin or metronidazole +/- aminoglycoside (depending on the severity of the condition) . Cefepime and cefpirome are new 4th generation parenteral cephalosporins with a spectrum of activity which makes them suitable for the treatment of infections caused by a wide variety of bacteria . They are active against both gram-positive and gram-negative organisms, including Staphylococcus aureus and Pseudomonas aeruginosa with activity comparable to or greater than that of cefotaxime or ceftazidime respectively . Cefepime in particular is also very active against strains of Enterobacter and Pseudomonas spp resistant to these two agents . In comparison with 3rd generation cephalosporins, cefepime appears to be less likely to induce resistance, due to a lower rate of hydrolysis by beta-lactamases, a low affinity for these enzymes and more rapid permeation into the cell . Despite the fact that a 4th generation cephalosporin is well-suited for the treatment of polymicrobial infections, the following should be kept in mind: (I) MRSA strains and Bacteroides fragilis group are not included in their spectrum of activity . (II) Cefpirome is the only cephalosporin with in vitro activity against Enterococci . (III) Severe surgical infections of nosocomial origin, and particularly in settings where Enterobacter spp predominate, represent the major indication for empirical use of a 4th generation cephalosporin in combination with a nitroimidazole.

J Chemother, 1999 Dec, 11(6), 453 - 63
New advances in the use of antimicrobial agents in surgery: intra-abdominal infections; Cinat ME et al.; Advances in both technical methods and antimicrobial therapy have significantly reduced morbidity and mortality for secondary (enterogenous) or community-acquired intra-abdominal infections . Presumptive antimicrobial therapy for most community-acquired intra-abdominal infection can be safely initiated with a single broad-spectrum antimicrobial effective against the expected Enterobacteriaceae and anaerobic flora . Beta-lactams and carbapenems are effective against gram-negative rods and anaerobes, achieve therapeutic levels rapidly, and have low toxicity in the absence of penicillin allergy . Second generation cephalosporins (e.g . cefoxitin and cefotetan) remain useful in surgical prophylaxis and treatment of mild community-acquired pneumonia, but limitations in their spectra and antimicrobial resistance restrict their utility in more serious infections . The fourth generation cephalosporins are also effective, but should be combined with other antimicrobials such as metronidazole for adequate anaerobic coverage . Preliminary data on new fluoroquinolones are scant, but promising results were obtained in one clinical trial . We predict the current trend toward the use of broad-spectrum single agent antimicrobials for therapy of intra-abdominal infection will continue.

J Chemother, 1999 Dec, 11(6), 440 - 5
Antimicrobial chemotherapy in the control of surgical infectious complications; de Lalla F; In spite of the progress in surgical technique and antibiotic prophylaxis, postoperative infection still accounts for both the commonest surgical complication and one of the most frequent nosocomial infections, also causing an increase in duration and costs of hospital stay . The choice of treatment for post-surgical infections requires an understanding of the usual infecting flora, available antimicrobial agents, and susceptibility patterns . The most common organisms in simple wound infection are gram-positive cocci and mainly Staphylococcus aureus . Staphylococcus epidermidis and S . aureus (quite often methicillin-resistant strains) are the organisms which predominate in the infectious complications following clean surgical procedures with implantation of vascular grafts or prosthetic devices . Mixed aerobic and anaerobic flora are mainly responsible for cases of intra-abdominal and intra-pelvic postoperative infections: the most common aerobes are Enterobacteriaceae (Escherichia coli, Proteus spp., and others) and enterococci, and among anaerobes Bacteroides fragilis group prevails . Adequate drainage and surgical control of the source of infection, when needed, and adjunctive effective antimicrobial therapy are important factors in successful treatment of postoperative infections . Semisynthetic penicillinase-resistant penicillins and glycopeptides (vancomycin and teicoplanin) are the drugs of choice for the treatment of infections caused by penicillin-resistant methicillin-sensitive, and methicillin-resistant, respectively, S . aureus and S . epidermidis . For the treatment of intra-abdominal and intra-pelvic infections, animal and human studies support the recommendation that treatment should be directed against both gram-negative enteric and anaerobic bacteria . Combinations of aminoglycosides with clindamycin or metronidazole have been widely used with great success; however adverse reactions such as nephrotoxicity and ototoxicity have been a problem in some patients . In recent years monotherapy with either a carbapenem (imipenem/cilastatin or meropenem) or a penicillin/beta-lactamase inhibitor combination has been proposed . Among these combination antimicrobials, piperacillin combined with tazobactam is a very well designed formulation . Indeed, piperacillin is active against a broad range of gram-negative and gram-positive pathogens, and tazobactam is a potent beta-lactamase inhibitor which acts on a variety of clinically important plasmid and chromosomal beta-lactamases . This combination seems particularly attractive for the treatment of mixed polymicrobial anaerobic-aerobic infections such as intra-abdominal and intra-pelvic postoperative infections.

Hum Immunol, 2000 Feb, 61(2), 140 - 7
HLA-B27 transgenic mice are susceptible to collagen-induced arthritis: type II collagen as a potential target in human disease; Lee S et al.; HLA-B27 is highly linked with a group of human diseases called spondyloarthropathies (SpA) . Many of these disorders begin after an infection with an enterobacteria . The symptoms seen in patients with spondyloarthropathies are inflammatory pain in the spine and asymmetrical arthritis of lower limbs . Additional symptoms related to SpA include inflammation in the eyes, bowel, and skin . The autoantigen(s) in SpA are not known . Proteins such as collagen and proteoglycans have been thought to be potent autoantigens in arthritidis including B27-associated human diseases . Type II collagen is a common denominator among eyes and joints, affected tissues in B27-linked diseases . Moreover, a few reports indicated CII specific T cells and antibodies in patients with spondyloarthropathies . We and others have previously described development of spontaneous arthritis and nail disease in HLA-B27 transgenic animals . To determine whether CII may be a target antigen in the B27-linked diseases, B27 + m beta 2 m% (HLA-B27) transgenic mice lacking mouse beta 2m with and without human beta 2m) mice were immunized with type II collagen inside the barrier facility . Male HLA-B27 transgenic mice developed collagen-induced arthritis compared to transgene negative littermates or female counterparts . There was no difference in the incidence of arthritis in HLA-B27 transgenic mice with and without human beta 2m . Our data suggest that beta 2m free heavy chain of HLA-B27 may present soluble antigens such as type II collagen to trigger specific T cells contributing in the development of arthritis . Our data also suggest that CII may be a potential target antigen in the cartilage during the disease process.

J Food Prot, 2000 Mar, 63(3), 386 - 94
Isolation and characterization of antagonists for the biocontrol of the postharvest wound pathogen Botrytis cinerea on strawberry fruits; Guinebretiere MH et al.; Antagonistic bacteria and yeasts were isolated from the epiphytic flora of stored strawberry fruits and evaluated for their ability to protect strawberry fruit wounds after harvest against Botrytis cinerea . Among selected potential antagonists, three strains of Candida reukaufii (5L3, 10CL4, 10L2) and one strain of Candida pulcherima (10L8) still protected fruit wounds when applied at 10(3) CFU/wound, reducing lesion or conidiophore development . In the same conditions, two Enterobacteriaceae (10B1, 5B4) highly reduced pathogen development . Strain 5B4 was still highly inhibitory when inoculated at 10(2) CFU/wound . The six strains applied on fruits did not produce any significant change in color, brightness, and firmness of fruits . The two yeasts, 5L3 and 10L8, and particularly the two bacteria, 5B4 and 10B1, were selected for further studies . The four antagonists effectively colonized fruit wounds and strongly inhibited spore germination of B . cinerea in vitro . The bacterial cells surrounded the germinating spores of B . cinerea and attachment of 5L3 cells on germinating spores were additionally observed . Bacterial antagonists, particularly the strain 5B4, multiplied and rapidly used carbohydrates in strawberry fruit juice despite the low pH (pH 3.5) . The efficiency of the bacterial antagonists on fruit wounds was related to their growth and nutritional properties.

Plant Foods Hum Nutr, 1999, 54(3), 207 - 16
Production of African breadfruit (Treculia africana) and soybean (Glycine max) seed based food formulations, 2: Effects of germination and fermentation on microbiological and physical properties; Ariahu CC et al.; The effects of germination (G) and naturally fermented (F) on the bacterial flora, viscosities and moisture sorption isotherms of soybean (S) and African breadfruit (B) seed based food products were investigated . Bacillus, Enterobacter, Enterobacteriaceae, Proteus, Serratia and Staphylococcus species dominated in the nonfermented products . Lactobacillus, Leuconostoc, Pediococcus and yeast species dominated in the fermented products whose gruels also inhibited growth of coagulase positive Staphylococcus aureus in challenge tests . Germination and fermentation resulted in significant (p < 0.05) decreases in cooked paste viscosities which is advantageous in increasing nutrient density . The monolayer moisture contents (g H2O/g solid) and surface areas for monolayer adsorption (m2/g solid) derived from BET model were 0.0422 and 148.1 (GFSB); 0.0428 and 150.4 (NGFSB); 0.0436 and 153.3 (NGNFSB); 0.0531 and 186.6 (GNFSB), respectively.

Appl Microbiol Biotechnol, 2000 Feb, 53(2), 180 - 4
Studies on nutritional and oxygen requirements for production of L-asparaginase by Enterobacter aerogenes; Mukherjee J et al.; The carbon and nitrogen sources most suitable for L-asparaginase production by Enterobacter aerogenes were selected and their concentrations optimized in shake-flask cultures . Sodium citrate (1.0%) and diammonium hydrogen phosphate (0.16%) proved to be the best sources of carbon and nitrogen, respectively . Nitrogen catabolite repression of enzyme formation was absent in this bacterium . Cultivation in a reactor showed that the dissolved oxygen level is the limiting factor for L-asparaginase production by E . aerogenes . Glucose was found to be a repressor of enzyme synthesis . Asparagine was absent intracellularly when the L-asparaginase level was high . An increase in the extracellular alanine level when the dissolved oxygen remained low indicated a shift from aerobic to fermentative metabolism.

Biochem Biophys Res Commun, 2000 Mar 16, 269(2), 526 - 31
Cloning and characterization of the UDP-sugar hydrolase gene (ushA) of Enterobacter aerogenes IFO 12010; Lee KS et al.; A bacterial alkaline phosphatase (BAP, the phoA gene product) is primarily responsible for the hydrolysis of the substrates 5-bromo-4-chloro-3-indolylphosphate-p-toluidine (XP) and p-nitrophenyl phosphate (pNPP) . Using these substrates and an E . coli phoA mutant, we have cloned Enterobacter aerogenes genes conferring an XP(+) phenotype . Two types of clones were identified based on phenotypic tests and DNA sequences . One of them is a E . aerogenes phoA gene (XP(+), pNPP(+)) as expected; surprisingly the other one was found to be a ushA gene (XP(+), pNPP(-)), which encodes an UDP (uridine 5'-diphosphate)-sugar hydrolase . The E . aerogenes ushA gene shares high sequence identity with ushA of E . coli and the mutationally silent ushA0 gene of Salmonella typhimurium at both the nucleotide (over 79%) and amino acid (over 93%) levels . Expression of the E . aerogenes ushA gene in E . coli produced high level of UDP-sugar hydrolase, as confirmed by TLC (thin layer chromatography) analysis together with a presence of a strong band due to a XP hydrolysis on a polyacrylamide gel .

Sante, 1999 Nov-Dec, 9(6), 341 - 4
{Typing of extended-spectrum beta-lactamase-producing Salmonella typhimurium strains isolated in a pediatric unit}; Mhand RA et al.; Extended-spectrum b-lactamases (ESBLs) derive mainly from TEM and SHV b-lactamases . These enzymes confer resistance to all oxyimino cephalosporins and monobactams except cephamycins and carbapems . ESBLs are often encoded by large plasmids that carry resistance determinants to multiple antibiotics and spread among the members of the Enterobacteriaceae . Since the first outbreak of Klebsiella pneumoniae expressing an extended-spectrum beta-lactamase reported in 1984, nosocomial infections due to Enterobacteriaceae species which produce ESBLs have been generally recovered from patients hospitalized in intensive care units . The most frequently isolated ESBL-producing strains belong to the genus Klebsiella, Escherichia, Enterobacter and Proteus; ESBLs are rarely associated with the genus Salmonella . The first Salmonella were detected in France in 1984 (Salmonella typhimurium), in Tunisia in 1988 (Salmonella wien) and in Argentina in 1991 (Salmonella typhimurium) . In 1994, 10 isolates of Salmonella typhimurium expressing an extended-spectrum beta-lactamase were isolated for the first time from 10 children hospitalized in a pediatric unit of the hospital Ibn-Rochd, Casablanca . Previous study showed that all isolates belonged the same serotype, and biotype, and showed a resistance to oxyimino beta-lactams, gentamycin, tobramycin and trimethoprim-sulfamethoxazole but remained susceptible to tetracycline, chloramphenicol and quinolones . Oxyimino beta-lactams resistance determinant of all strains of Salmonella typhimurium was transferred by conjugation to Escherichia coli; Resistance to gentamycin and trimethoprim-sulfamethoxazole was also cotransferred . In this study, we characterized the relationship between all isolates by comparing plasmid profiles and patterns of proteins because there appear to be the more effective method for evaluating epidemiologic relationship between Salmonella species, and the protein profiles method has been used for many bacterial species . These two methods have the advantages of speed and simplicity . All isolates presented the same plasmid pattern characterised by three plasmids and the same pattern of proteins composed of 36 bands . We concluded by combining results that this outbreak involved the spread of the same strain of Salmonella typhimurium between the ten children . As this type of resistance is easily transferred by these isolates to other bacterial species, the major risk would be its transfer to Salmonella typhi.

J Antimicrob Chemother, 2000 Mar, 45(3), 295 - 303
Activity and spectrum of 22 antimicrobial agents tested against urinary tract infection pathogens in hospitalized patients in Latin America: report from the second year of the SENTRY antimicrobial surveillance program (1998); Gales AC et al.; The potency and spectrum of various antimicrobial agents tested against 434 bacterial isolates causing urinary tract infection (UTI) in hospitalized patients in Latin America were evaluated . The genotypes of the extended-spectrum beta-lactamase-producing and selected multi-resistant isolates were also evaluated by molecular typing techniques . Escherichia coli (60.4%) was the most common aetiological agent causing UTI, followed by Klebsiella spp . (11.2%) and Pseudomonas aeruginosa (8.3%) . In contrast, Enterococcus spp . isolates caused only 2.3% of UTIs . Fewer than 50% of E . coli isolates were susceptible to broad-spectrum penicillins . The resistance rates to ciprofloxacin and the new quinolones were also high among these isolates . The molecular characterization of ciprofloxacin-resistant E . coli showed that most of them have a double mutation in the gyrA gene associated with a single mutation in the parC gene . The Klebsiella pneumoniae isolates studied demonstrated high resistance rates to beta-lactam drugs, including broad-spectrum cephalosporins . The carbapenems were the compounds with the highest susceptibility rate among these isolates (100.0% susceptible) followed by cefepime (91.7% susceptible) . Meropenem, imipenem and cefepime were also the most active drugs against Enterobacter spp . Among P . aeruginosa isolates, meropenem (MIC(50), 2 mg/L) was the most active compound, followed by imipenem (MIC(50), 4 mg/L), cefepime (MIC(50), 8 mg/L) and ceftazidime (MIC(50), 16 mg/L) . The results presented in this report confirm that bacterial resistance continues to be a great problem in Latin American medical institutions.

Vet Microbiol, 2000 Feb, 71(3-4), 211 - 22
Virulence factors and genetic relatedness of Escherichia coli strains isolated from pigs with post-weaning diarrhea; Osek J; Forty-six Escherichia coli strains isolated from post-weaning diarrhea of pigs were analysed for their phenotypic and genotypic properties . The isolates were of serogroups O138, O139, and O141 and most of them possessed hemolytic activities . PCR analysis showed that 34 of the isolates harboured the genes for shiga toxin 2e and 32 strains possessed the genes for heat-stable enterotoxins I and II . Ten strains had the fedA gene of F18 fimbriae . The genetic relationships among all isolates were tested by random amplified polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC) PCR analyses . Using the RAPD test with two different primers, six fingerprints were distinguished whereas the ERIC analysis revealed only three DNA patterns . Some strains possessing identical phenotypic and genotypic virulence determinants exhibited distinct RAPD profiles and some isolates with different pathogenic markers showed the same RAPD and ERIC pictures . Thus, RAPD, and to a less extent ERIC techniques, revealed intra- and interserogroup genotypic variations among the E . coli strains analyzed.

Appl Occup Environ Hyg, 2000 Mar, 15(3), 303 - 12
Characterization of an aerosol chamber for human exposures to endotoxin; Taylor L et al.; The objective of this study was to develop and characterize an exposure chamber in which human subjects could be exposed to low dust concentrations carrying an endotoxin coating . An exposure chamber, dust dispersion method, and endotoxin characterization technique were developed for inhalation exposures . A 6.27 m3 exposure chamber was designed and constructed from cinder block, glass windows, and Plexiglas . Using an acetone adhesion process, Enterobacter agglomerans were adsorbed onto respirable cellulose particles to create the endotoxin aerosol . The size distribution of the endotoxin-treated particles was verified using light microscopy and cascade impactors . A dry powder dust generator was refined to consistently disperse small quantities of the aerosol into the chamber to maintain dust concentrations at approximately 250 micrograms/m3 . Dust levels during the chamber exposures were monitored using a portable continuous aerosol monitor (PCAM) . During initial exposure runs, PCAM monitoring stations were positioned at different locations within a 0.5-meter matrix to document mixing patterns . Total dust and cascade impactor samples were collected throughout each exposure period to characterize the chamber operating system and insure the mean airborne dust concentration fulfilled target levels . A one-factor analysis of variance at the 95 percent confidence interval illustrated that there was not a statistically significant difference in the mean dust concentration throughout the exposure runs compared to the individual runs . Together the consistency of the total dust filters, endotoxin concentrations, and aerosol-monitoring instrument were adequate to allow use of the chamber for experimental studies involving human volunteers.

Appl Environ Microbiol, 2000 Mar, 66(3), 1195 - 201
Selected chitinase genes in cultured and uncultured marine bacteria in the alpha- and gamma-subclasses of the proteobacteria; Cottrell MT et al.; PCR primers were patterned after chitinase genes in four gamma-proteobacteria in the families Alteromonadaceae and Enterobacteriaceae (group I chitinases) and used to explore the occurrence and diversity of these chitinase genes in cultured and uncultured marine bacteria . The PCR results from 104 bacterial strains indicated that this type of chitinase gene occurs in two major groups of marine bacteria, alpha- and gamma-proteobacteria, but not the Cytophaga-Flavobacter group . Group I chitinase genes also occur in some viruses infecting arthropods . Phylogenetic analysis indicated that similar group I chitinase genes occur in taxonomically related bacteria . However, the overall phylogeny of chitinase genes did not correspond to the phylogeny of 16S rRNA genes, possibly due to lateral transfer of chitinase genes between groups of bacteria, but other mechanisms, such as gene duplication, cannot be ruled out . Clone libraries of chitinase gene fragments amplified from coastal Pacific Ocean and estuarine Delaware Bay bacterioplankton revealed similarities and differences between cultured and uncultured bacteria . We had hypothesized that cultured and uncultured chitin-degrading bacteria would be very different, but in fact, clones having nucleotide sequences identical to those of chitinase genes of cultured alpha-proteobacteria dominated both libraries . The other clones were similar but not identical to genes in cultured gamma-proteobacteria, including vibrios and alteromonads . Our results suggest that a closer examination of chitin degradation by alpha-proteobacteria will lead to a better understanding of chitin degradation in the ocean.

J Clin Microbiol, 2000 Mar, 38(3), 1187 - 90
Novel screening method for urine cultures using a filter paper dilution system; Kunin CM et al.; We have developed a novel method for urine culture for office practice based on the use of filter paper as a solid-phase dilution device . Filtration dilutes and spreads the inoculum onto a solid culture surface . Experiments were conducted to determine the optimum inoculum size, microbial permeability through filter papers, and ability to exclude vaginal epithelial cells . The filter paper dilution system was compared to the standard streak method to detect bacteriuria in specimens submitted to the diagnostic laboratory . The sensitivity and specificity of the filter paper dilution system for detection of high-count (>/=10(4) CFU/ml) gram-negative bacteriuria in 487 urine specimens were 98.2 and 97.4%, respectively . The sensitivity and specificity for gram-positive bacteriuria in 404 urine specimens were 91.2 and 99.2%, respectively . Low-count gram-negative bacteriuria (<10(4) CFU/ml) was detected by the filter paper dilution system in five of nine specimens (55.6%) . In addition, the filter paper dilution system was able to detect gram-negative bacteria in 12 of 41 (29.3%) mixed cultures . Lactobacillus and Gardnerella organisms in urine specimens were excluded by the filter paper dilution system . Only three of eight Candida sp . isolates were detected at counts of >/=10(4) CFU/ml . The system has good storage properties and can be inoculated at the point of source without the need for refrigeration or preservatives . It should be a useful screening method for office practice, where members of the family Enterobacteriaceae and staphylococci cause most infections . Standard culture methods are preferred for hospital diagnostic microbiology laboratories, where there is a need to detect yeasts and fastidious microorganisms and to isolate individual colonies from mixed cultures.

J Clin Microbiol, 2000 Mar, 38(3), 1048 - 52
Imipenem resistance of enterobacter aerogenes mediated by outer membrane permeability; Bornet C et al.; Multidrug-resistant Enterobacter aerogenes strains are increasingly isolated in Europe and especially in France . Treatment leads to imipenem resistance, because of a lack of porin . We studied the evolution of resistance in 29 strains isolated from four patients during their clinical course . These strains belonged to the prevalent epidemiological type observed in France in previous studies (C . Bosi, et al., J . Clin . Microbiol . 37:2165-2169, 1999; A . Davin-Regli et al., J . Clin . Microbiol . 34:1474-1480, 1996) . They also harbored a TEM-24 extended-spectrum beta-lactamase-coding gene . Thirteen strains were susceptible to gentamicin and resistant to imipenem and cefepime . All of the patients showed E . aerogenes strains with this resistance after an imipenem treatment . One patient showed resistance to imipenem after a treatment with cefpirome . Twelve of these 13 strains showed a lack of porin . Cessation of treatment with imipenem for three patients was followed by reversion of susceptibility to this antibiotic and the reappearance of porins, except in one case . For one patient, we observed three times in the same day the coexistence of resistant strains lacking porin and susceptible strains possessing porin . The emergence of multidrug-resistant E . aerogenes strains is very disquieting . In our study, infection by E . aerogenes increased the severity of the patients' illnesses, causing a 100% fatality rate.

J Clin Microbiol, 2000 Mar, 38(3), 1016 - 22
Comparison of different PCR approaches for typing of Francisella tularensis strains; de la Puente-Redondo VA et al.; In this study, we evaluated three PCR methods for epidemiological typing of Francisella tularensis: repetitive extragenic palindromic element PCR (REP-PCR), enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), and random amplified polymorphic DNA (RAPD) assay with both M13 and T3-T7 primers . The analysis was performed with 40 strains of F . tularensis isolated from hares, humans, ticks, and a vole . On the basis of the combination of REP, ERIC, and RAPD fingerprints, F . tularensis strains were divided into 17 genetic groups (designated A to Q), and one Francisella novicida strain was classified in group R . The F . novicida strain is of special concern, since previous genetic methods have been unable to clearly distinguish between F . tularensis and F . novicida . The F . tularensis isolates recovered from hares were included in groups A to J, M, and P; those recovered from humans were included in groups A, D, G, J, L, O, and N; those isolated from ticks were included in groups B and Q; and that recovered from a vole was in group K . The diversities calculated for the 40 F . tularensis isolates, according to Simpson's index, were 0.14 for REP-PCR, 0.52 for ERIC-PCR, 0.39 for RAPD assay with the M13 primer (RAPD/M13-PCR), and 0.65 for RAPD/T3-T7-PCR, and the diversity increased up to 0.90 when ERIC-PCR, RAPD/M13-PCR, and RAPD/T3-T7-PCR were combined . Our results suggest that although limited genetic heterogeneity among F . tularensis strains was observed, this small variation is enough to validate the PCR methods used in this study and their combinations, because they can provide safe, useful, and rapid tools for the typing of F . tularensis.

J Food Prot, 2000 Feb, 63(2), 216 - 21
Characterization of whey cheese packaged under vacuum; Pintado ME et al.; Vacuum packaging was assayed at 4 degrees C and was tested in comparison to unpackaged counterparts, in both microbiological and physicochemical terms, in studies pertaining to the preservation of Requeijao, a traditional Portuguese whey cheese . Bacteria were absent (i.e., <10 CFU/g) in whey cheeses on the day of manufacture as a result of thermal processing . After storage, both unpackaged and packaged cheeses exhibited high viable counts of Bacillus, Pseudomonas, Enterobacteriaceae, and lactic acid bacteria (especially lactococci) . Yeasts, staphylococci, enterococci, and spore-forming clostridia were severely inhibited by the package vacuum combined with the increasing acidification developed therein . Whey cheeses packaged under vacuum underwent substantial acidification, slight depletion of lactose, and no significant variation in moisture content or texture; conversely, unpackaged whey cheeses exhibited substantial loss of water and a concomitant increase in rigidity . Vacuum packaging strongly inhibited lipolysis (even if viable counts of some microbial groups were high); saturated fatty acids (mainly C16:0 and C14:0) accounted for ca . 73% of the total free-fatty acid content, whereas the most concentrated unsaturated fatty acids were C18:1 and C18:2 (ca . 14% each) . The conclusions generated in our study are, in general, useful for a wide range of whey cheeses worldwide: i.e., Requeson (Spain), Ricotta (Italy), Broccio (France), and Anthotyro (Greece) . In addition, our conclusions are particularly helpful in terms of improving the safety of Requeijao, a widely acclaimed dairy specialty.

Biochemistry, 2000 Mar 7, 39(9), 2164 - 73
Role of the loop containing residue 115 in the induced-fit mechanism of the bacterial cell wall biosynthetic enzyme MurA; Schonbrunn E et al.; The induced-fit mechanism in Enterobacter cloacae MurA has been investigated by kinetic studies and X-ray crystallography . The antibiotic fosfomycin, an irreversible inhibitor of MurA, induced a structural change in UDP-N-acetylglucosamine (UDPGlcNAc)-liganded enzyme with a time dependence similar to that observed for the inactivation progress . The mechanism of action of fosfomycin on MurA appeared to be of the bimolecular type, the overall rate constants of inactivation and structural change being = 104 M(-1) s(-1) and = 85 M(-1) s(-1), respectively . Fosfomycin as well as the second MurA substrate, phosphoenolpyruvate (PEP), are known to interact with the side chain of Cys115 . Like wild-type MurA, the catalytically inactive single-site mutant protein Cys115Ser structurally interacted with UDPGlcNAc in a rapidly reversible reaction . However, in contrast to wild-type enzyme, binding of PEP to mutant protein induced a rate-limited, biphasic structural change . Fosfomycin did not affect the structure of the mutant protein . The crystal structure of unliganded Cys115Ser MurA at 1.9 A resolution revealed that the overall conformation of the loop comprising residues 112-121 is not influenced by the mutation . However, other than Cys115 in wild-type MurA, Ser115 exhibits two distinct side-chain conformations . A detailed view on the loop revealed the existence of an elaborate hydrogen-bonding network mainly supplied by water molecules, presumably stabilizing its conformation in the unliganded state . The comparison between the known crystal structures of MurA, together with the kinetic data obtained, suggest intermediate conformational states in the MurA reaction, in which the loop undergoes multiple structural changes upon ligand binding.

Jpn J Antibiot, 1999 Dec, 52(12), 695 - 720
{Antimicrobial activities of meropenem against clinically isolated strains in 1997}; Suzuki Y et al.; In order to evaluate antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates in 1997 . The results were as follows; 1 . Antimicrobial activities of MEPM against Gram-positive bacteria were stronger than those of cephems (CEPs) and were approximately equal to those of imipenem (IPM) and panipenem (PAPM) . 2 . Carbapenems showed strong antimicrobial activities against Enterobacteriaceae, Glucose non-fermentative Gram-negative rods and Bacteroides fragilis group that were multiple drug resistant including the third generation CEPs . Antimicrobial activities of MEPM against these organisms were stronger than those of IPM and PAPM . By comparing antimicrobial activities of MEPM against Gram-negative bacteria in 1997 with those obtained in 1993, increase of resistance was not observed . 3 . MIC-ranges of MEPM were low against the resistant strains of Pseudomonas aeruginosa to IPM and PAPM . It was considered that these resistant strains were not expressing oprD products (D2 porin protein), forming main outer membrane porin channels of carbapenems and basic amino acids.

Jpn J Antibiot, 1999 Dec, 52(12), 690 - 4
{In vitro activity of biapenem (BIPM) against clinically isolated respiratory pathogens in 1996-1998}; Watanabe A et al.; The in vitro antibacterial activity of biapenem (BIPM), a new carbapenem antibiotic, was compared with those of imipenem (IPM), panipenem (PAPM), meropenem (MEPM), ceftazidime (CAZ) and piperacillin (PIPC) against 280 isolates of 9 respiratory pathogens . The MIC90s of biapenem (BIPM) for methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pneumoniae, Moraxella catarrhalis, Pseudomonas aeruginosa, and Haemophilus influenzae were 0.12, 32, 0.25, 0.06, 4 and 8 micrograms/ml, respectively . In comparison with other antibiotics, the activity of biapenem (BIPM) for P . aeruginosa was as potent as meropenem (MEPM), but for H . influenzae it was slightly less than those of other antibiotics, and for other respiratory pathogens it was as potent as those of other antibiotics . The MIC90s of biapenem (BIPM) for Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae and Serratia marcescens were 0.06, 1, 1, 0.5 microgram/ml, respectively, and which were equal to or somewhat lower than those of other antibiotics . Biapenem (BIPM) showed strong activity against Gram-positive and Gram-negative pathogens, especially P . aeruginosa in general . Based on these results, biapenem (BIPM) is seemed to be highly useful antibiotic for the treatment of respiratory infections with several organism.

J Bacteriol, 2000 Mar, 182(6), 1609 - 15
Evolution of arginine biosynthesis in the bacterial domain: novel gene-enzyme relationships from psychrophilic Moritella strains (Vibrionaceae) and evolutionary significance of N-alpha-acetyl ornithinase; Xu Y et al.; In the arginine biosynthetic pathway of the vast majority of prokaryotes, the formation of ornithine is catalyzed by an enzyme transferring the acetyl group of N-alpha-acetylornithine to glutamate (ornithine acetyltransferase {OATase}) (argJ encoded) . Only two exceptions had been reported-the Enterobacteriaceae and Myxococcus xanthus (members of the gamma and delta groups of the class Proteobacteria, respectively)-in which ornithine is produced from N-alpha-acetylornithine by a deacylase, acetylornithinase (AOase) (argE encoded) . We have investigated the gene-enzyme relationship in the arginine regulons of two psychrophilic Moritella strains belonging to the Vibrionaceae, a family phylogenetically related to the Enterobacteriaceae . Most of the arg genes were found to be clustered in one continuous sequence divergently transcribed in two wings, argE and argCBFGH(A) {"H(A)" indicates that the argininosuccinase gene consists of a part homologous to known argH sequences and of a 3' extension able to complement an Escherichia coli mutant deficient in the argA gene, encoding N-alpha-acetylglutamate synthetase, the first enzyme committed to the pathway} . Phylogenetic evidence suggests that this new clustering pattern arose in an ancestor common to Vibrionaceae and Enterobacteriaceae, where OATase was lost and replaced by a deacylase . The AOase and ornithine carbamoyltransferase of these psychrophilic strains both display distinctly cold-adapted activity profiles, providing the first cold-active examples of such enzymes.

J Immunol, 2000 Mar 1, 164(5), 2674 - 83
Neutrophil activation by bacterial lipoprotein versus lipopolysaccharide: differential requirements for serum and CD14; Soler-Rodriguez AM et al.; Neutrophil activation plays an important role in the inflammatory response to Gram-negative bacterial infections . LPS has been shown to be a major mediator of neutrophil activation which is accompanied by an early down-regulation of L-selectin and up-regulation of CD1lb/CD18 . In this study, we investigated whether lipoprotein (LP), the most abundant protein in the outer membrane of bacteria from the family Enterobacteriaceae, can activate neutrophils and whether this activation is mediated by mechanisms that differ from those used by LPS or Escherichia coli diphosphoryl lipid A (EcDPLA) . Neutrophil activation was assessed by measuring down-regulation of L-selectin and up-regulation of CD11b/CD18 . When comparing molar concentrations of LP vs EcDPLA, LP was more potent (four times) at activating neutrophils . In contrast to LPS/EcDPLA, LP activation of neutrophils was serum independent . However, LP activation of neutrophils was enhanced by the addition of soluble CD14 and/or LPS-binding protein . In the presence of serum, LP activation of neutrophils was inhibited by different mAbs to CD14 . This inhibition was significantly reduced or absent when performed in the absence of serum . Diphosphoryl lipid A from Rhodobacter spheroides (RaDPLA) completely inhibited LPS/EcDPLA activation of neutrophils but only slightly inhibited LP activation of neutrophils . These results suggest that LP activation of human neutrophils can be mediated by a mechanism that is different from LPS activation and that LP is a potentially important component in the development of diseases caused by Gram-negative bacteria of the family Enterobacteriaceae.

J Agric Food Chem, 2000 Feb, 48(2), 451 - 6
Chemical and microbiological characteristics of ewes' milk cheese manufactured with extracts from flowers of Cynara cardunculus and Cynara humilis as coagulants; Vioque M et al.; The chemical and microbial characteristics as well as the flavor and aroma of Los Pedroches cheese made using aqueous extracts of Cynara cardunculus L . flowers were compared with those of cheeses manufactured with extracts of Cynara humilis L . throughout ripening . The two thistle species assayed were found to have no appreciable effect on the moisture, fat, protein, and NaCl contents of the cheese or on its water activity, flavor, and aroma; however, the use of C . humilis resulted in reduced lactic acid content (p < 0.001) and higher pH values (p < 0.05) relative to those of cheese specimens produced with C . cardunculus . The protein breakdown of the cheeses was assessed in terms of soluble nitrogen (SN), nonprotein nitrogen (NPN), and amino acid nitrogen (AAN) . Proteolysis was more marked and rapid in cheese containing C . cardunculus as coagulant, the SN and NPN contents of which were significantly higher (p < 0 . 01) than those of the cheese obtained with the species C . humilis; AAN contents were similar in both species of Cynara throughout ripening . Although total viable, coliform, and lactobacilli counts were similar in cheeses produced with both types of plant coagulant throughout ripening, enterobacteria and yeasts counts (p < 0.01) and molds counts (p < 0.05) were higher in cheese produced with C . humilis than in cheese obtained with C . cardunculus.

Eur J Clin Microbiol Infect Dis, 1999 Dec, 18(12), 902 - 7
Evaluation of an automated system for identification of Enterobacteriaceae and nonfermenting bacilli; Jossart MF et al.; The performance of the Vitek 2 (bioMerieux, France), a new fully automated system allowing rapid identification of microorganisms and susceptibility testing, and the Vitek 2 ID-GNB card (bioMerieux) was evaluated using 502 clinical isolates and stock collection strains of gram-negative rods belonging to 70 taxa . The number of isolates correctly identified to species and genus levels was 430 (85.7%) and 485 (96.6%), respectively . Clinical isolates of both Enterobacteriaceae and non-Enterobacteriaceae were better identified at the species level (95.3% and 74%, respectively) than stock collection strains (86.4% and 52.2%, respectively) . The Vitek 2 ID-GNB card provides after 3 h a highly acceptable level of accuracy for identification of Enterobacteriaceae and non-Enterobacteriaceae, including most atypical strains encountered in clinical situations.

Clin Ther, 2000 Jan, 22(1), 66 - 75
Pharmacokinetics and pharmacodynamics of cefepime administered by intermittent and continuous infusion; Burgess DS et al.; OBJECTIVE: This study assessed the pharmacokinetics and pharmacodynamics of cefepime administered by intermittent and continuous infusion against clinical isolates of Pseudomonas aeruginosa, Enterobacter cloacae, and Staphylococcus aureus . BACKGROUND: Because beta-lactam antibiotics exhibit time-dependent bactericidal activity and lack prolonged postantibiotic effects against many bacteria, the goal of therapy is to maintain serum drug concentrations above the minimum inhibitory concentration (MIC) for the relevant pathogen over most of the dosing interval . Continuous infusion is a mode of drug administration that can provide serum drug concentrations continuously above the MIC for most bacterial pathogens . METHODS: Twelve healthy volunteers were enrolled . Each received cefepime 2 g by intermittent bolus q12h and, on another day, was randomly assigned to receive 4 or 3 g administered by continuous infusion over 24 hours . RESULTS: For the intermittent regimen, the mean (+/- SD) pharmacokinetic findings were: maximum serum concentration, 112.9 +/- 21.1 microg/mL; minimum serum concentration, 1.3 +/- 0.5 microg/mL; and half-life, 2.6 +/- 0.4 hours . For the 3- and 4-g continuous infusion regimens, steady-state serum concentrations (C(SS)) were 13.9 +/- 3.8 and 20.3 +/- 3.3 microg/mL, respectively . MICs ranged from 2 to 4, 0.125 to 8, and 2 to 8 microg/mL against P . aeruginosa, E . cloacae, and S . aureus, respectively . For the intermittent regimen, serum inhibitory titers (SITs) at 24 hours were > or = 1:2 in 46% of subjects against P . aeruginosa, 48% against E . cloacae, and 2% against S . aureus . For both continuous infusion regimens, SITs for each organism were > or = 1:2 in all subjects . CONCLUSIONS: The intermittent regimen maintained serum concentrations above the MIC for P . aeruginosa and E . cloacae in > or = 92% (11/12) of subjects for > or = 70% of the dosing interval, provided the MIC was < or = 4 microg/mL . Both continuous infusion regimens provided a C(SS) above the MIC for all organisms . However, the C(SS) was > or = 4 times the MIC only if the MIC was < or = 2 microg/mL . Only the 4-g regimen provided such concentrations against isolates with an MIC of 4 microg/mL, and neither regimen provided such concentrations when the MIC was 8 microg/mL . These findings should be applied in comparative clinical studies.

Rinsho Biseibutshu Jinsoku Shindan Kenkyukai Shi, 1999 Dec, 10(2), 83 - 9
{Evaluation of inoculum density prepared by prompt inoculation system and antimicrobial susceptibility test results by the automated MicroScan WalkAway system}; Nakasone I et al.; The Prompt Inoculation System adapted to the susceptibility testing by the automated microbiology system, MicroScan WalkAway (Dade MicroScan Inc., West Sacramento, CA, U.S.A.) was evaluated by determining colony forming units (cfu) per ml of the inocula and by the susceptibility test results obtained through repeated testing of the American Type Culture Collection (ATCC) reference strains described by the National Committee for Clinical Laboratory Standards (NCCLS) . The colony forming units per ml of the inocula prepared by the Prompt ranged 2x10++(5) to 2x10(6)++ cfu/ml for the ATCC reference strains, the results indicating that the Prompt gave a higher inoculum density and was more reproducible when compared to the standard turbidity, McFarland adjustment . Also, most inocula prepared from the clinical isolates, comprising the strains of Enterobacteriaceae,no-entericbacilli,staphylococci,enterococci, and streptococci,contained 1x10(6) to 3x10(6) cfu/ml . Although the inocula prepared by the Prompt contained more viable bacterial cells, the outcome results for susceptibility testing by the MicroScan WalkAway were highly acceptable . Four ATCC reference strains were repeatedly tested . Of 540 MIC determinations, 489 (90 . 6%) were within the acceptable MIC ranges described by the NCCLS M100-S9, whereas the inocula prepared by the photometric adjustment gave 87.4% . In conclusion, the Prompt inocula were found to give more precise susceptibility test results mostly equivalent to those obtained from inocula prepared by the conventional photometric procedures.

Mycoses, 1999, 42(11-12), 619 - 27
Bacterial flora accompanying Candida yeasts in clinical specimens; Hermann C et al.; From 1986 to 1988, in the prefluconazole era, 67,765 clinical specimens from the Gottingen University Hospital were investigated for bacteria and fungi in our institution . Oral and throat swabs, respiratory secretions, gastric juices, faeces, urine, genital swabs, blood, wound secretions and skin swabs were analysed for yeast-like fungi, and opportunistic or pathogenic bacteria . A total of 5195 specimens (7.7%) yielded Candida spp . alone or in combination with bacteria (fungal (F-) group) and 62,570 specimens yielded bacteria only or remained sterile (non-fungal group, N-group) . Elevated rates of accompanying bacteria were detected with Candida spp . colonizing blood, urine, and skin . Among the dominant bacterial isolates, the distribution of staphylococci and enterococci did not reflect a distinct association pattern . Among the enterobacterial isolates from patients in intensive care, colonization patterns of the throat, gastric juices, and faeces reflected the use of a selective decontamination of the digestive tract (SDD) . A statistically significant association between Candida and enterobacteria of the genus Enterobacter which was unaffected by SDD, was observed throughout this study . Such an association pattern was also observed, to a lesser extent, with the related genera Klebsiella and Serratia, but not with Escherichia coli.

Antimicrob Agents Chemother, 2000 Mar, 44(3), 583 - 9
Inactivation of the ampD gene in Pseudomonas aeruginosa leads to moderate-basal-level and hyperinducible AmpC beta-lactamase expression; Langaee TY et al.; It has been shown in enterobacteria that mutations in ampD provoke hyperproduction of chromosomal beta-lactamase, which confers to these organisms high levels of resistance to beta-lactam antibiotics . In this study, we investigated whether this genetic locus was implicated in the altered AmpC beta-lactamase expression of selected clinical isolates and laboratory mutants of Pseudomonas aeruginosa . The sequences of the ampD genes and promoter regions from these strains were determined and compared to that of wild-type ampD from P . aeruginosa PAO1 . Although we identified numerous nucleotide substitutions, they resulted in few amino acid changes . The phenotypes produced by these mutations were ascertained by complementation analysis . The data revealed that the ampD genes of the P . aeruginosa mutants transcomplemented Escherichia coli ampD mutants to the same levels of beta-lactam resistance and beta-lactamase expression as wild-type ampD . Furthermore, complementation of the P . aeruginosa mutants with wild-type ampD did not restore the inducibility of beta-lactamase to wild-type levels . This shows that the amino acid substitutions identified in AmpD do not cause the altered phenotype of AmpC beta-lactamase expression in the P . aeruginosa mutants . The effects of AmpD inactivation in P . aeruginosa PAO1 were further investigated by gene replacement . This resulted in moderate-basal-level and hyperinducible expression of beta-lactamase accompanied by high levels of beta-lactam resistance . This differs from the stably derepressed phenotype reported in AmpD-defective enterobacteria and suggests that further change at another unknown genetic locus may be causing total derepressed AmpC production . This genetic locus could also be altered in the P . aeruginosa mutants studied in this work.

Antimicrob Agents Chemother, 2000 Mar, 44(3), 561 - 7
ampR gene mutations that greatly increase class C beta-lactamase activity in Enterobacter cloacae; Kuga A et al.; The ampC and ampR genes of Enterobacter cloacae GN7471 were cloned into pMW218 to yield pKU403 . Four mutant plasmids derived from pKU403 (pKU404, pKU405, pKU406, and pKU407) were isolated in an AmpD mutant of Escherichia coli ML4953 by selection with ceftazidime or aztreonam . The beta-lactamase activities expressed by pKU404, pKU405, pKU406, and pKU407 were about 450, 75, 160, and 160 times higher, respectively, than that expressed by the original plasmid, pKU403 . These mutant plasmids all carried point mutations in the ampR gene . In pKU404 and pKU405, Asp-135 was changed to Asn and Val, respectively . In both pKU406 and pKU407, Arg-86 was changed to Cys . The ease of selection of AmpR mutations at a frequency of about 10(-6) in this study strongly suggests that derepressed strains, such as AmpD or AmpR mutants, could frequently emerge in the clinical setting.

Chirurgie, 1999 Dec, 124(6), 626 - 31
{Hepatectomy in intrahepatic lithiasis}; Do KS et al.; STUDY AIM: The aim of this study was to report the immediate results of a series of 65 hepatic resections for hepatolithiasis performed in Vietnam . PATIENTS AND METHOD: From 1986 to 1998, 44 men and 21 women (mean age: 40 years) underwent hepatic resection for hepatolithiasis . Fourty patients had previously undergone one or several operations for hepatolithiasis . The procedure was performed on emergency in 25 patients . Indications for hepatic resection were: angiocholitis and liver abscess in 22 cases, stones closely inserted in the biliary duct in 20 cases, hemobilia in 12 cases, stones located above a biliary stricture in 8 cases and stones associated with a postoperative biliary fistula in 3 cases . Liver resections (minor in 61 patients, including 55 left lobectomies, and major in 4 patients) were performed through transhepatic approach according to the Ton That Tung technique and followed by an external biliary drainage with a Kehr tube . RESULTS: There were 6 postoperative deaths (9%), 3 due to septic shock, 2 to cachexia, and 1 to liver failure . The 15 patients with complications recovered with conservative therapy . Bile infection was present in 93%, mostly with Escherichia coli and Enterobacter . Pigmented stones were usually found . CONCLUSION: Vietnam is a country with high incidence of hepatolithlasis . Hepatic resection is an adequate treatment for localized intrahepatic bile duct stones when the involved segment including biliary strictures and calculi can be completely removed . The procedure may be performed on emergency for liver abscess, or hemobilia.

Pathol Biol (Paris), 1999 Dec, 47(10), 1075 - 9
{Multidrug resistant bacteria in a psychiatric milieu}; Eveillard M et al.; Isolation rates of multiple-drug resistant (MDR) bacteria were evaluated retrospectively in a psychiatric care facility . Over the six-year study period, 66 MDR bacterial strains were found . Methicillin-resistant Staphylococcus aureus contributed half of all MDR strains and 31% of all S . aureus strains . Among Pseudomonas aeruginosa strains, 22% were resistant to ticarcillin or imipenem, and among Enterobacteriaceae, 4.1% were MDR strains (production of a derepressed cephalosporinase or of an extended-spectrum beta-lactamase) . Although most MDR strains were probably acquired during hospitalizations in short-term care facilities outside our institution, patient-to-patient transmission, either direct or via other individuals, cannot be ruled out . These data indicate that psychiatric care facilities should adopt the MDR strain monitoring strategies already used in other hospitals.

Res Microbiol, 1999 Nov-Dec, 150(9-10), 627 - 39
Short palindromic repetitive DNA elements in enterobacteria: a survey; Bachellier S et al.; We present a survey of short palindromic repetitive elements in enterobacteria . Seven families are presented . Five were already known (RSA, IRU, 29-bp repeats, BIMEs and boxC), and their properties are updated; in particular, a new composite element is shown to include the formerly identified boxC repeats . Two repetitions, YPAL1 and YPAL2, found primarily in Yersinia, are described here for the first time.

Acta Neurochir (Wien), 1999, 141(12), 1303 - 8
Nosocomial infections in a neurosurgery intensive care unit; Dettenkofer M et al.; In order to identify overall and site-specific nosocomial infection (NI) rates in patients receiving neurosurgical intensive care therapy, a prospective study was started in February 1997 in the eight-bed neurosurgical ICU of the University Hospital of Freiburg, Germany . Case records were reviewed twice a week, all microbiology reports were reviewed and ward staff was consulted . NI were defined according to the CDC-criteria and were categorised into specific infection sites . Within 20 months, 545 patients with a total of 5,117 patient days were investigated (mean length of stay: 9.4 days) . 113 NI were identified in 90 patients (72 pts . with one, 13 with two and 5 with three infections, respectively) . A moderate to high overall incidence (20.7/100 pts.) and a moderate incidence density (22.1/1,000 patient days) of NI in the neurosurgical ICU could be documented; these figures are well within the range of published data . Site specific incidence rates and incidence densities were: 1 bloodstream infection per 100 patients (0.9 central line-associated BSIs per 1,000 central line-days), 9 pneumonias per 100 patients (15.1 ventilator-associated pneumonias per 1,000 ventilator-days), 7.3 urinary tract infections per 100 patients (8.5 urinary catheter-associated UTIs per 1,000 urinary catheter-days) . Additionally, 1.1 cases of meningitis, 0.7 brain abscesses/ventriculitis, and 1.7 other infections (surgical site infection, bronchitis, catheter related local infection, diarrhoea) were documented per 100 patients, respectively . 14.6% of isolated pathogens were E . coli, 10.2% enterococci, 9.6% S . aureus, 6.4% CNS, 6.4% Klebsiella spp., 5% Enterobacter spp . and 5% Pseudomonas spp . In 11 cases of NI no pathogen could be isolated.

Digestion, 2000, 61(1), 39 - 46
Protective effect of lafutidine against indomethacin-induced intestinal ulceration in rats: relation to capsaicin-sensitive sensory neurons; Kato S et al.; BACKGROUND/AIM: We examined the prophylactic effect of lafutidine, a novel histamine H(2)-receptor antagonist {(+/-)-2-(furfurylsulfinyl)-N-{4-{4-(piperidinomethyl)-2-pyr idyl}oxy- (Z)-2 butenyl}acetamide}, on indomethacin-induced small intestinal ulcers in rats and investigated the relation of this action to capsaicin-sensitive sensory neurons . METHODS AND RESULTS: Subcutaneously administered indomethacin (10 mg/kg) provoked ulceration in the small intestine, mainly the jejunum and ileum, accompanied by increases in myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities as well as the enterobacterial numbers invading the mucosa . Intestinal ulcerogenic response to indomethacin was prevented by 16,16-dimethyl prostaglandin E(2) (10 microg/kg, p.o.) and capsaicin (10 mg/kg, p.o . ) as well as ampicillin (800 mg/kg, p.o.), but not omeprazole (100 mg/kg, p.o.) . Likewise, lafutidine (1-10 mg/kg, p.o.), but not cimetidine (100 mg/kg, p.o.), reduced the occurrence of intestinal ulcers in response to indomethacin in a dose-dependent manner, and a significant effect was observed at 3 mg/kg or greater . The protective action of lafutidine as well as capsaicin was almost totally abolished by chemical ablation of capsaicin-sensitive sensory neurons . Both lafutidine and capsaicin significantly suppressed the increases in MPO and iNOS activities as well as enterobacterial numbers in the mucosa . These agents also significantly enhanced mucus secretion in the small intestine . CONCLUSION: These results suggest that lafutidine protects the small intestine against ulceration via stimulation of capsaicin-sensitive sensory neurons . This action may be attributable to inhibition of enterobacterial invasion in the intestinal mucosa, probably by increasing the mucus secretion .

J Med Microbiol, 2000 Feb, 49(2), 177 - 85
Clonal groups of enteropathogenic Escherichia coli isolated in case-control studies of diarrhoea in Bangladesh; Ansaruzzaman M et al.; Recent case-control studies in Bangladesh showed a high prevalence of enteropathogenic Escherichia coli (EPEC) strains (identified by DNA probes for virulence genes) associated with childhood diarrhoea . However, the clonal status of these strains is not known . A total of 94 EPEC isolates from 80 children with diarrhoea and 14 healthy matched controls isolated during 1991-1992 and 1993-1994 was characterised by serogrouping, enterobacterial repetitive intergenic consensus sequence PCR, and by a biochemical fingerprinting method (the phene plate or PhP system) . Twelve O serogroups were found with O114 (n = 19) and O127 (n = 23) being the dominant serogroups . Most strains of O114 belonged to the same PhP/PCR types . Strains of O127 contained 16 that produced cytolethal distending toxin (CDT) and seven that did not; both were found among patients as well as controls . Results of PCR and PhP typing showed that CDT-positive strains belonged to the same clonal group and were related to one of the two PhP/PCR types of CDT-negative O127 strains . Thirty-one EPEC strains were O non-typable and 21 strains belonged to other less prevalent serogroups . These strains belonged to diverse PhP/PCR types and did not show any similarity to the strains of two major serogroups, O114 and O127 . The results suggest that two clonal groups of EPEC strains are predominantly associated with childhood diarrhoea in Bangladesh.

J Am Vet Med Assoc, 2000 Feb 1, 216(3), 359 - 63
Bacteria associated with pyothorax of dogs and cats: 98 cases (1989-1998); Walker AL et al.; OBJECTIVE: To determine the organisms most commonly isolated from pleural fluid from dogs and cats with pyothorax . DESIGN: Retrospective study . ANIMALS: 51 dogs and 47 cats . PROCEDURE: Results of bacteriologic culture of pleural fluid samples obtained by means of thoracentesis were obtained from medical records . To obtain information on in vitro antimicrobial susceptibility of organisms commonly isolated from dogs and cats, records of all dogs and cats examined during 1998 were reviewed, and information was obtained on identity and in vitro antimicrobial susceptibility of aerobic organisms isolated from samples other than urine or urinary tract samples . RESULTS: Median ages of dogs and cats were 4 years . Bacteria were isolated from pleural fluid samples from 47 of 51 (92%) dogs and 45 of 47 (96%) cats . Obligate anaerobic bacteria were isolated from 28 dogs and 40 cats . A mixture of obligate anaerobic and facultative bacteria was isolated from 17 dogs and 20 cats . Samples from cats most often yielded a member of the nonenteric group (most commonly members of the genus Pasteurella), whereas those from dogs more often yielded a member of the family Enterobacteriaceae (most commonly E coli) . CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that antimicrobial agents chosen for the initial treatment of dogs and cats with pyothorax should be active against a mixture of obligate anaerobic and facultative bacteria.

Crit Care Med, 2000 Jan, 28(1), 67 - 73
Bacterial contamination of ready-to-use 1-L feeding bottles and administration sets in severely compromised intensive care patients; Mathus-Vliegen LM et al.; OBJECTIVE: In intensive care patients, enteral feeding requires sterile feedings because of infectious complications and adequate supplements to meet nutritional needs . Heretofore, prepacked, large-volume formula containers were developed, but bacterial contamination occurred in 4% to 15% . Our objective was to investigate the microbial contamination rate of 1-L feeding bottles and newly designed administration sets over hanging times of 24 hrs in the intensive care unit (ICU) . DESIGN AND SETTING: A prospective observational cohort study of patients admitted to the ICU of a university hospital . PATIENTS: All consecutive patients fed via a nasojejunal tube for at least 4 days . MEASUREMENTS: Cultures of feeding bottles, administration sets, and gastric and tracheobronchial aspirates at day 0, 1, 2, 4, and 7 . RESULTS: A total of 4% of feeding bottles and 74% of infusion sets contained >10(2) colony forming units (CFU)/mL . Gastric and bronchial aspirates were positive in 90% and 92%, respectively . Bacterial counts of feeding bottles were 10(2)-10(5) CFU/mL, and the main bacteria isolated included Enterobacter cloacae, Klebsiella oxytoca, and enterococci . One third of all cultured bacteria in feeding bottles, administration sets, stomach, and lungs belonged to the Enterobacteriaceae family, which was held responsible for the nosocomial infections in the ICU . None of the 1-L feeding bottles with a hanging time of 19-24 hrs was contaminated . Only bottles that had to be exchanged because of need for a faster rate of infusion proved to be contaminated, apparently without clinical consequences . With time and the increasing severity of disease, the administration sets became contaminated at an increasingly faster rate and with higher bacterial counts mainly through retrograde growth of endogenous bacteria . The final step of bottle contamination might have been the bacterial transfer by nurses' hands . CONCLUSION: Despite an almost ideal design of the enteral nutrition delivery system, a 4% contamination rate of initially sterile feedings with clinically relevant bacteria and the fact that only manipulated systems showed bacterial growth are of concern.

Pediatr Radiol, 2000 Jan, 30(1), 33 - 4
Enterobacter sakazakii brain abscess in the neonate: the importance of neuroradiologic imaging; Burdette JH et al.; BACKGROUND: Enterobacter sakazakii is a rare but important cause of life-threatening neonatal sepsis and meningitis complicated by the development of brain abscess . OBJECTIVE: Given the neurotropic qualities of this organism, early diagnosis and treatment are crucial as a poor prognosis follows brain abscess formation . MATERIALS AND METHODS: Cross-sectional imaging (CT and MRI) play an important role in the diagnostic work-up . CONCLUSION: A biopsy-proven case of E . sakazakii brain abscess, which was diagnosed on MR images, is presented, and the importance of prompt radiologic imaging of the central nervous system in the work-up of patients with this life-threatening disease is discussed.

Biotechnol Prog, 2000 Jan-Feb, 16(1), 17 - 25
Stable, long-term bacterial production of soluble, dimeric, disulfide-bonded protein pharmaceuticals without antibiotic selection; Mantile G et al.; Numerous biopharmaceuticals and other recombinant biotechnology products are made in prokaryotic hosts . However, bacterial production of native, biologically active eukaryotic proteins is rarely possible for disulfide-bonded and/or multisubunit proteins . We previously described the production of soluble, native disulfide-bonded dimeric proteins in the Escherichia coli cytoplasm (Miele et al., 1990; Mantile et al., 1993) . Native, biologically active proteins with up to six disulfide bonds have been produced with our expression system (Garces et al., 1997) . However, plasmid instability during induction limited its usefulness . We now report the stable, high-level expression of soluble, disulfide-bonded human uteroglobin without antibiotic selection . We designed a new vector containing a multifunctional stabilization region that confers complete plasmid stability and increased protein yields without copy number increases . Recombinant expression remains fully inducible after long-term continuous culture in nonselective liquid medium (at least 260 generations) . This system may significantly expand the applications of bacterial expression to recombinant production of soluble, bioactive proteins for biochemical studies and biopharmaceutical/industrial purposes . As a result of the very broad activity spectrum of the stabilization region we selected, its use could be extended to bacterial hosts other than enterobacteria.

Pharmacol Res, 1999 Dec, 40(6), 517 - 24
Roles of enterobacteria, nitric oxide and neutrophil in pathogenesis of indomethacin-induced small intestinal lesions in rats; Konaka A et al.; Roles of enterobacteria, nitric oxide (NO) and neutrophil in indomethacin-induced small intestinal lesions were examined in rats . Indomethacin (10 mg kg-1), administered s.c . as a single injection, caused haemorrhagic lesions in the small intestine, mostly in the jejunum and ileum . The lesions were first observed 6 h after administration of indomethacin, the severity increasing progressively with time up to 24 h later . Following indomethacin, the enterobacterial numbers, inducible NO synthase (iNOS) activity and NO production in the intestinal mucosa were also increased with time, and changes in the former preceded those in the latter two as well as the occurrence of intestinal damage . Treatment of the animals with both NG-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine prevented intestinal lesions induced by indomethacin, with suppression of NO production . Both dexamethasone and FR167653 (an inhibitor of interleukin-1 beta/tumour necrosis factor-alpha production) also reduced the severity of intestinal lesions as well as the increase in iNOS activity following administration of indomethacin . Likewise, the occurrence of intestinal lesions was attenuated by pretreatment of the animals with anti-neutrophil serum (ANS) . None of these treatments, however, affect the translocation of enterobacteria in the mucosa . By contrast, ampicillin (an anti-bacterial agent) suppressed the increase in mucosal iNOS activity as well as the enterobacterial numbers invaded in the mucosa and inhibited the occurrence of intestinal lesions after administration of indomethacin . These results strongly suggest that enterobacterial translocation in the mucosa is the first step required for activation of various factors such as iNOS/NO and neutrophils, all involved in the pathogenesis of indomethacin-induced intestinal lesions.

Jpn J Antibiot, 1999 Nov, 52(11), 667 - 79
{In vitro antibacterial activities of carbapenems against clinical isolates}; Murase M; Antibacterial activities of four carbapenems, imipenem, panipenem, meropenem, and biapenem, were determined using 353 strains belonging to 18 bacterial species which were isolated from clinical materials at Ehime University Hospital . The MIC values of these carbapenems against MRSA were widely distributed between 0.1 and 100 micrograms/ml, and MIC90 values of these 4 carbapenems were 25-50 micrograms/ml . Any of these carbapenems prevented the bacterial growth of enterobacteriaceae of 8 bacterial species excluding S . macrescens at concentrations of 1 microgram/ml or less . The MIC values against P . aeruginosa showed relatively wide distribution, being 0.39-25 micrograms/ml for imipenem, 0.2-25 micrograms/ml for panipenem, 0.1-12.5 micrograms/ml for meropenem, and 0.2-12.5 micrograms/ml for biapenem . From those results, it was confirmed that any of the carbapenems tested had a wide antibacterial spectrum and strong antibacterial activities.

Microbiology, 2000 Jan, 146 ( Pt 1), 165 - 71
cDNA-AFLP analysis of differential gene expression in the prokaryotic plant pathogen Erwinia carotovora; Dellagi A et al.; For studies of differential gene expression in prokaryotes, methods for synthesizing representative cDNA populations are required . Here, a technique is described for the synthesis of cDNA from the potato pathogens Erwinia carotovora subsp . atroseptica (Eca) and Erwinia carotovora subsp . carotovora (Ecc) using a combination of short oligonucleotide (11-mer) primers that were known to anneal to conserved sequences in the 3' regions of enterobacterial genes . Specific PCR amplifications with primers designed to anneal to 14 known genes from either Eca or Ecc revealed the presence of the corresponding transcripts in cDNA, suggesting that the cDNA represented a broad genomic coverage . cDNA-amplified fragment length polymorphism (cDNA-AFLP) was used to identify differentially expressed genes in Eca, including one that shows significant similarity, at the protein level, to an avirulence gene from Xanthomonas campestris pv . raphani . Northern analysis was used to confirm that differentially amplified cDNA fragments were derived from differentially expressed genes . This is the first report of the use of cDNA-AFLP to study differential gene expression in prokaryotes.

J Clin Microbiol, 2000 Feb, 38(2), 570 - 4
Ability of the VITEK 2 advanced expert system To identify beta-lactam phenotypes in isolates of Enterobacteriaceae and Pseudomonas aeruginosa; Sanders CC et al.; The Advanced Expert System (AES) was used in conjunction with the VITEK 2 automated antimicrobial susceptibility test system to ascertain the beta-lactam phenotypes of 196 isolates of the family Enterobacteriaceae and the species Pseudomonas aeruginosa . These isolates represented a panel of strains that had been collected from laboratories worldwide and whose beta-lactam phenotypes had been characterized by biochemical and molecular techniques . The antimicrobial susceptibility of each isolate was determined with the VITEK 2 instrument, and the results were analyzed with the AES to ascertain the beta-lactam phenotype . The results were then compared to the beta-lactam resistance mechanism determined by biochemical and molecular techniques . Overall, the AES was able to ascertain a beta-lactam phenotype for 183 of the 196 (93.4%) isolates tested . For 111 of these 183 (60.7%) isolates, the correct beta-lactam phenotype was identified definitively in a single choice by the AES, while for an additional 46 isolates (25.1%), the AES identified the correct beta-lactam phenotype provisionally within two or more choices . For the remaining 26 isolates (14.2%), the beta-lactam phenotype identified by the AES was incorrect . However, for a number of these isolates, the error was due to remediable problems . These results suggest that the AES is capable of accurate identification of the beta-lactam phenotypes of gram-negative isolates and that certain modifications can improve its performance even further.

J Clin Microbiol, 2000 Feb, 38(2), 542 - 6
Detection of extended-spectrum beta-lactamases in clinical isolates of Enterobacter cloacae and Enterobacter aerogenes; Tzelepi E et al.; The aim of the present study was to investigate the frequency of extended-spectrum beta-lactamases (ESBLs) in a consecutive collection of clinical isolates of Enterobacter spp . The abilities of various screening methods to detect ESBLs in enterobacters were simultaneously tested . Among the 68 consecutive isolates (56 Enterobacter cloacae and 12 Enterobacter aerogenes isolates) that were analyzed for beta-lactamase content, 21 (25 and 58%, respectively) possessed transferable ESBLs with pIs of 8.2 and phenotypic characteristics of SHV-type enzymes, 8 (14.3%) of the E . cloacae isolates produced a previously nondescribed, clavulanate-susceptible ESBL that exhibited a pI of 6.9 and that conferred a ceftazidime resistance phenotype on Escherichia coli transconjugants, and 2 E . cloacae isolates produced both of these enzymes . Among the total of 31 isolates that were considered ESBL producers, the Vitek ESBL detection test was positive for 2 (6.5%) strains, and the conventional double-disk synergy test (DDST) with amoxicillin-clavulanate and with expanded-spectrum cephalosporins and aztreonam was positive for 5 (16%) strains . Modifications of the DDST consisting of closer application of the disks (at 20 instead of 30 mm), the use of cefepime, and the use of both modifications increased the sensitivity of this test to 71, 61, and 90%, respectively . Of the 37 isolates for which isoelectric focusing failed to determine ESBLs, the Vitek test was false positive for 1 isolate and the various forms of DDSTs were false-positive for 3 isolates.

World J Urol, 1999 Dec, 17(6), 339 - 44
The bowel microflora: an important source of urinary tract pathogens; Tannock GW; The large bowel is home to a complex microbial community that is present throughout the life of the human host . Relatively few microbial species detected in faeces in relatively low numbers have been implicated as major aetiological agents of urinary tract infections . The impact of these few species on human health is considerable, especially when recurrent urinary tract infections are considered, and ways must be found to reduce their pathogenic activities . One approach may be to learn about the ecology of the bowel ecosystem and devise ways by which the numbers of enterobacteria, in particular, can be restricted . This, in turn, would decrease the dose of potential urinary tract pathogens present in the faeces.

Appl Environ Microbiol, 2000 Feb, 66(2), 614 - 9
Molecular characterization of Irish Salmonella enterica serotype typhimurium: detection of class I integrons and assessment of genetic relationships by DNA amplification fingerprinting; Daly M et al.; Salmonella enterica is among the principal etiological agents of food-borne illness in humans . Increasing antimicrobial resistance in S . enterica is a cause for worldwide concern . There is concern at present in relation to the increasing incidence of human infection with antimicrobial agent-resistant strains of S . enterica serotype Typhimurium, in particular of phage type DT104 . Integrons appear to play an important role in the dissemination of antimicrobial resistance genes in many Enterobacteriaceae including S . enterica . In this study the antimicrobial susceptibilities and phage types of 74 randomly collected strains of S . enterica serotype Typhimurium from the Cork region of southern Ireland, obtained from human, animal (clinical), and food sources, were determined . Each strain was examined for integrons and typed by DNA amplification fingerprinting (DAF) . Phage type DT104 predominated (n = 48) . Phage types DT104b (n = 3), -193 (n = 9), -195 (n = 6), -208 (n = 3), -204a (n = 2), PT U302 (n = 1), and two nontypeable strains accounted for the remainder . All S . enterica serotype Typhimurium DT104 strains were resistant to ampicillin, chloramphenicol, streptomycin, Sulfonamide Duplex, and tetracycline, and one strain was additionally resistant to trimethoprim . All DT104 strains but one were of a uniform DAF type (designated DAF-I) and showed a uniform pattern of integrons (designated IP-I) . The DT104b and PT U302 strains also exhibited the same resistance phenotype, and both had the DAF-I and IP-I patterns . The DAF-I pattern was also observed in a single DT193 strain in which no integrons were detectable . Greater diversity of antibiograms and DAF and IP patterns among non-DT104 phage types was observed . These data indicate a remarkable degree of homogeneity at a molecular level among contemporary isolates of S . enterica serotype Typhimurium DT104 from animal, human, and food sources in this region.

Appl Environ Microbiol, 2000 Feb, 66(2), 543 - 8
Dissimilatory metal reduction by the facultative anaerobe Pantoea agglomerans SP1; Francis CA et al.; Anaerobic enrichments with acetate as the electron donor and Fe(III) as the terminal electron acceptor were obtained from sediments of Salt Pond, a coastal marine basin near Woods Hole, Mass . A pure culture of a facultatively anaerobic Fe(III) reducer was isolated, and 16S rRNA analysis demonstrated that this organism was most closely related to Pantoea (formerly Enterobacter) agglomerans, a member of the family Enterobacteriaceae within the gamma subdivision of the Proteobacteria . This organism, designated strain SP1, can grow by coupling the oxidation of acetate or H(2) to the reduction of a variety of electron acceptors, including Fe(III), Mn(IV), Cr(VI), and the humic substance analog 2,6-anthraquinone disulfonate, but not sulfate . To our knowledge, this is the first mesophilic facultative anaerobe reported to couple acetate oxidation to dissimilatory metal reduction.

Ann Fr Anesth Reanim, 1999 Dec, 18(10), 1054 - 60
{Impact of initial antibiotic therapy on the course of resistance to fluoroquinolones and aminoglycosides in Gram-negative bacilli isolated from intensive care patients}; Mathon L et al.; OBJECTIVE: To evaluate the effect of the initial antibiotic therapy associating a betalactam antibiotic (BLA) with either an aminoglycoside (AG) or a fluoroquinolone (FQ) on the development of resistance of gram-negative bacilli in an intensive care unit . STUDY DESIGN: Prospective bacteriological surveillance study . PATIENTS: The study included 51 patients experiencing a second infection with gram-negative organisms, eight days or more after a first infection . METHOD: The incidences of bacterial infection and the antimicrobial susceptibility have been assessed . RESULTS: The first-choice therapy was based either on BLA + AG (51%), or on BLA + FQ in the others (46%) . The causative organisms were Enterobacteriaceae (57%) and Pseudomonas aeruginosa (31%) . The second infection occurred 23 +/- 11 days after the first . The main organisms involved were Pseudomonas aeruginosa (51%) and Enterobacteriaceae (41%) . In the group treated initially with an AG, only the antibiotic susceptibility for amikacin decreased significantly (72 vs 36%, p < 0.05) . The latter was the most prescribed antibiotic (56%) . In the FQ group, there was a significant decrease of susceptibility for ciprofloxacin, pefloxacin, netilmicin and tobramycin . The decrease was not significant for gentamicin and amikacin . CONCLUSIONS: In intensive care patients, the use of FQ in association with a BLA increases the resistance to AG and FQ . Therefore it seems preferable to administer an AG in association with a BLA . Amikacine should only be prescribed when justified for a given case.

Eur J Biochem, 2000 Feb, 267(3), 677 - 83
Viresin . A novel antibacterial protein from immune hemolymph of Heliothis virescens pupae; Chung KT et al.; Immune hemolymph was collected from fifth instar larvae and 1-day-old pupae of Heliothis virescens after injection of prepupae with live Enterobacter cloacae . Induction of antibacterial activity against Escherichia coli K12 D31 was 7.5 times greater in pupal than in larval immune hemolymph . Lysozyme activity of immune pupal hemolymph against Micrococcus lysodeikticus was 11 times greater when compared with lysozyme activity of immune larval hemolymph . Early pupal immune response with regard to antibacterial activity was much greater than larval immune response in H . virescens . Normal pupal hemolymph showed an increase in antibacterial activity and lysozyme that was induced during metamorphosis . Antibacterial protein was isolated together with lysozyme by gel filtration chromatography and then separated from lysozyme by sequential electrophoresis with a native acid gel and SDS gel . Molecular mass of antibacterial protein was estimated to be 12 kDa . The N-terminal amino acid sequence of 12-kDa protein was different from those of antibacterial molecules found in other insects and has not been identified before . A sample containing 12-kDa protein was negative for immunoblotting with anti-synthetic cecropin B antibody . We have named the novel 12-kDa antibacterial protein viresin . Viresin showed antibacterial activity against several Gram-negative bacteria including E . cloacae but not against Gram-positive bacteria.

Phytochemistry, 1999 Dec, 52(8), 1479 - 82
Antibacterial activity of pure flavonoids isolated from mosses; Basile A et al.; Seven pure flavonoids were isolated and identified from five moss species . The flavonoids were the flavones apigenin, apigenin-7-O-triglycoside, lucenin-2, luteolin-7-O-neohesperidoside, saponarine and vitexin; and the biflavonoid bartramiaflavone . Some of these flavonoids were shown to have pronounced antibacterial effects against Enterobacter cloaceae, E . aerogenes and Pseudomonas aeruginosa (minimal bacteriostatic concentration MIC in the range of 4-2048 micrograms/ml) . Because of their antibacterial spectrum mainly active against Gram negative bacterial strains, responsible for severe opportunistic infections and resistant to common antibacterial therapy, these flavonoids may be important tools in antibacterial strategies.

J Food Prot, 2000 Jan, 63(1), 83 - 90
Gut mucosa morphology and microflora changes in malnourished mice after renutrition with milk and administration of Lactobacillus casei; Allori C et al.; Nutrition plays a key role in maintaining the balance of the intestinal microflora . Malnutrition disturbs the ecological barrier and induces histological damage . We evaluated modifications induced by renutrition with nonfat milk (NFM) and Lactobacillus casei administration (for 2 days) on the bacterial gut population and structural and ultrastructural gut modifications in malnourished mice . Balb/c mice suffering from a malnutrition process immediately after weaning (for 21 days) were divided into four groups and were given NFM for 0, 7, 14, and 21 days . Another group was treated in a similar way, but after different periods of NFM administration, mice in this group received L . casei for two consecutive days . All experimental animals were sacrificed by cervical dislocation, and both the microflora and the histological structure of the intestine were studied . In malnourished animals, a decrease in the numbers of Lactobacillus and anaerobic microorganisms was observed, whereas there was an increase in the number of Enterobacteriaceae . In animals treated with NFM and NFM plus L . casei, we could observe an important improvement in the microflora in the small and large intestines but no differences between both treatments . Structural and ultrastructural studies showed a slight improvement 7 days after treatment with NFM, and for 14 and 21 days after renutrition, the mice showed normal intestinal villi, whereas the additional feeding with L . casei for two consecutive days, after different periods of renutrition, yielded an earlier improvement (7 days).

J Food Prot, 2000 Jan, 63(1), 71 - 7
Effect of L-glucose and D-tagatose on bacterial growth in media and a cooked cured ham product; Bautista DA et al.; Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria . This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham . Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, approximately 2 to 7%, usually in the form of dextrose and corn syrup solids . Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents . An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria . L-Glucose and D-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of D-glucose . Results showed that both L-glucose and D-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica . In a separate study, D-glucose, L-glucose, and D-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored . Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P < 0.05) slower for the formulation containing D-tagatose than those containing L- or D-glucose . Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P < 0.20) change in the presence of any of the sugars used in the meat formulations . Compared to the control sample containing D-glucose, the shelf life of the chopped and formed ham containing D-tagatose at 10 degrees C was extended by 7 to 10 days . These results indicate that D-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.

J Perinatol, 1999 Mar, 19(2), 127 - 31
Early detection of bacteremia in the neonatal intensive care unit using the new BACTEC system; Pauli I Jr et al.; OBJECTIVE: With the newer techniques of culture analysis such as the BACTEC 9240 fluorometric detection system, detecting bacteremia in the neonate may be possible in a significantly shorter time . We hypothesized that neonatal bacteremia can be detected in less than 48 hours by this method . STUDY DESIGN: Our study included a retrospective review of 613 blood cultures obtained during the period August 1, 1995 to March 18, 1996 taken from 325 infants who had cultures drawn with a sepsis work-up and/or repeat cultures who had initial positive cultures in our Neonatal Intensive Care Unit . Results of blood cultures were studied in conjunction with the variables of body weight, gestational age, organism grown, complete blood count (CBC), and timing of positive cultures . Statistical analyses were performed using Fisher's and two-tailed Student's t tests . RESULTS: The results showed that of 325 infant blood cultures 49 (15%) were positive . Of these, 64% were coagulase-negative staphylococci, 14% viridans streptococci, 8% Escherichia coli, 4% Enterococcus sp., 4% Pseudomonas sp., 2% Enterobacter sp., 2% Klebsiella sp., and 2% Candida albicans . Of the positive blood cultures taken from infants not on antibiotics at the time of culture, 54% were detected positive at 18 hours, 71% at 24 hours, and 100% by 30 hours . Detection time by organism type was as follows: coagulase-negative staphylococci, 21.7 hours; viridans streptococci, 15.6 hours; E . coli, 7.5 hours; Enterococcus sp., 12 hours; Enterobacter sp., 5 hours; Klebsiella sp., 10 hours; and Pseudomonas sp., 12 hours . CONCLUSION: Our results indicate that the BACTEC 9240 fluorometric detection system helps in early identification of neonatal bacteremia (in 24 to 30 hours), with Gram-negative organisms being detected earlier than Gram-positive organisms (p < 0.05) and having significantly higher immature neutrophils in a CBC (I:T ratio of > or = 0.2 (p < 0.001) . Early detection of neonatal bacteremia using this method will allow earlier diagnosis and appropriate treatment of the potentially bacteremic and bacteremic infant.

Minerva Urol Nefrol, 1999 Sep, 51(3), 181 - 5
{"Classic" vs autolubricant catheterization for endovesicular chemotherapy . Preliminary experience}; Cindolo L et al.; AIM: The aim of this study was to evaluate the frequency of urinary tract infections (UTI) after catheterisation for instillation comparing two systems: the "classic" method and the catheterisation using a new autolubricant device: EasiCath Coloplast . METHODS: During the period of endovesical chemotherapy (between 4 and 48 weeks), 22 patients (6 females and 18 males) were studied, aged between 53 and 78 years old . We have performed 139 instillations using Nelaton Ch 14 or 12 type catheters lubricated with gel based on lidocaine, neomicyn and fluocinolone ("classic" method) . Instead 135 patients have been treated with autolubricant devices according to the manufacturer's instructions . After 48 hours from instillation, a total of 274 catheterisation have been examined using urine tests and urine culture with antibiogram . We administered a 5-point visual analogic score to the patients weighing the post-instillation dysuria . RESULTS: With "classic" method UTI frequency is 7.19% (10/139) . The most common pathogen has been E . coli (7/10) . With autolubricant catheters UTI frequency is 2.96 (4/135) . Klebsiella, Enterobacter, as well as E . coli (2/4) have been identified as pathogen . All patients with infections have been treated with targeted antibiotics based on the antibiogram . CONCLUSIONS: We have observed the people with autolubricant catheters left more comfort then those undergoing to the "classic" catheterisation . The frequency of post-catheterisation, dysuria was also reduced . Our data show that the new method is safer and easier to handle then the "classic" one . Moreover, common anaesthetic/antibiotic lubricant have important bacteriostatic effects that reduce the BCG viability.

Am J Gastroenterol, 2000 Jan, 95(1 Suppl), S5 - 7
Colonic food: pre- and probiotics; Bengmark S; The colonic mucosa is unable to nourish itself from the blood . Instead, its nutritive demand must be met from the lumen, where different nutrients, short-chain fatty acids, amino acids, polyamines, growth factors, vitamins, and antioxidants are produced by a nonpathogenic (commensal, so-called "protective" probiotic) flora . The substrates for the production of nutrients are usually referred to as prebiotics, which consist mainly of ingested fibers and complex proteins (colonic food), but may also include necrotic mucosal cells, mucus, gastrointestinal (GI) secretions, and bacteria (as well as yeasts broken down by the bacteria) . A characteristic common to all foods destined for the colon--colonic foods-is that no enzymes in the small intestine are capable of breaking them down . It is recommended that a minimum of 10% of ingested calories and about 20% of the food volume should be colonic food . The probiotic flora is today often found deficient, especially in industrialized nations . Studies have shown that Lactobacillus plantarum can preserve key nutrients, vitamins, and antioxidants; eliminate toxic components from food; protect food from decay; and eradicate pathogens such as Enterobacteriaceae, S . aureus, and enterococci from fermented food . In addition, it has demonstrated effectiveness over other bacteria in the metabolism of semiresistant oligofructans . L . plantarum-fermented oat given to healthy volunteers significantly reduces the gut content of potentially pathogenic microorganisms (PPMs).

J Bacteriol, 2000 Feb, 182(3), 833 - 6
Rapid turnover of FlhD and FlhC, the flagellar regulon transcriptional activator proteins, during Proteus swarming; Claret L et al.; The enterobacterial flhDC master operon activates expression of the flagellar biogenesis gene hierarchy and also represses cell division . During Proteus mirabilis differentiation into elongated hyperflagellated swarm cells, flhDC transcription is strongly but transiently increased . We show that concentration of the FlhD and FlhC proteins is also tightly controlled at the posttranslational level . This is achieved by protein degradation, which is most severe after differentiation when the half-life of both proteins is ca . 2 min . Degradation is energy dependent and putatively involves the Lon protease.

J Bacteriol, 2000 Feb, 182(3), 782 - 8
VisN and VisR are global regulators of chemotaxis, flagellar, and motility genes in Sinorhizobium (Rhizobium) meliloti; Sourjik V et al.; The known 41 flagellar, chemotaxis, and motility genes of Sinorhizobium (Rhizobium) meliloti contained in the "flagellar regulon" are organized as seven operons and six transcription units that map to a contiguous 45-kb chromosomal region . By probing gene expression on Western blots and with lacZ fusions, we have identified two master regulatory genes, visN and visR, contained in one operon . The gene products probably form a heterodimer, VisNR, acting as a global transcription activator of other flagellar genes . The related 27-kDa VisN and VisR proteins are LuxR-type proteins with typical ligand- and DNA-binding domains . The vis operon itself is constitutively transcribed; however, to activate flagellar genes, VisNR seemingly requires the binding of a yet-unknown effector . Gene expression in tester strains with known deficiencies revealed a hierarchy of three classes of flagellar genes: class I comprises visN and visR; class II, controlled by VisNR, comprises flagellar assembly (class IIA) and motor (class IIB) genes; and class III comprises flagellin and chemotaxis genes that require functional class I and class IIA genes for expression . In contrast to their enterobacterial counterparts, mot genes belong to class II without exerting control over class III genes . While the general hierarchy of gene expression resembles the enterobacterial scheme, the assignment of mot genes to class IIB and the global control by a LuxR-type VisNR activator are new features distinguishing the S . meliloti flagellar gene system.

J Gastroenterol, 2000, 35(1), 15 - 9
Overgrowth and translocation of Escherichia coli from intestine during prolonged enteral feeding in rats; Kayama S et al.; Our objective was to examine changes in bacterial flora in the gastrointestinal tract that might lead to their translocation during the prolonged enteral administration of an elemental liquid diet . Eleven rats (experimental group) received a feeding gastrostomy and were administered an intragastric infusion of a liquid elemental diet for 17 days, while 9 rats (control group) received chow and water ad libitum for 17 days . The animals were then killed and the mesenteric lymph nodes (MLNs), liver, jejunum, ileum, and cecum were aseptically removed, homogenized, and cultured for isolation of bacteria . A statistically significant increase in the population of a single species of Enterobacteriaceae, Escherichia coli, was observed in the ileum and cecum of the experimental group fed the liquid diet as compared with the control group . Five of the MLNs from the 11 experimental rats (45%) were positive for E . coli, as compared with none from the 9 control rats, a statistically significant difference (P = 0.038) . The E . coli isolated from the MLNs and the ileum of the experimental group exhibited the O168:H serotype . Our results suggest that E . coli isolated from the MLNs of the experimental group had translocated from the intestine . The animal model described here may be useful in screening for drugs to reduce the problem of translocation of intestinal bacteria.

Aust N Z J Med, 1999 Oct, 29(5), 684 - 92
Survey of blood cultures from five community hospitals in south-western Sydney, Australia, 1993-1994; Gosbell IB et al.; BACKGROUND: Blood culture results have profound implications for patients . Comprehensive overviews of blood cultures have been uncommon, and focused on tertiary referral hospitals . AIM: To present a review of blood culture results from a laboratory servicing community hospitals in Sydney, Australia . METHODS: Retrospective chart review of patients with positive blood cultures from 1 June 1993 to 31 May 1994 . RESULTS: During the survey period there were 107,382 hospital admissions; 12,109 blood culture sets from 9292 patients were processed . Of these 1197 sets were positive, representing 974 febrile episodes in 923 patients . There were 476 episodes of contamination . Of the episodes of true bacteraemia, Escherichia coli was isolated in 139, Staphylococcus aureus in 91 (22 methicillin-resistant), other enterobacteriaceae in 60, and Streptococcus pneumoniae in 5 1 . The diagnoses attributable to bacteraemia included intravenous catheter-related sepsis (122 episodes), urinary tract infection (88), bacteraemia from unknown source (79), intra-abdominal and biliary sepsis (91), pneumonia (35), and meningitis (21) . Sixty-eight patients died directly due to bacteraemia . Multivariate analysis showed underlying disease (OR 3.97) or shock (OR 28.1) predicted death . Blood cultures confirmed clinical diagnoses in 258 episodes, but made a de novo diagnosis in 205 episodes . CONCLUSIONS: This study describes the clinical and laboratory features of bacteraemias occurring in smaller public hospitals, as distinct from tertiary referral centres . It demonstrated that intravenous catheter-related sepsis was very common in smaller hospitals . The clinical diagnosis was frequently confirmed, and a de novo diagnosis was often established by a positive blood culture . Unfortunately nearly half the positive blood cultures represented contamination.

J Food Prot, 2000 Dec, 63(12), 1670 - 5
Microbial contamination of carcasses and equipment from an Iberian pig slaughterhouse; Rivas T et al.; The microbial contamination of carcasses and equipment has been studied in an industrial slaughterhouse of Iberian pigs . Samples of the surface of carcasses were taken at different stages of the process and aerobic plate count at 37 degrees C (APC), Enterobacteriaceae-count (E-count) and Escherichia coli-count (EC-count) were determined . It was demonstrated that in scalding and singeing the APC decreased (P < 0.01), while in the dehairing it increased (P < 0.01) . The E-count and EC-count decreased in the scalding but increased in the evisceration (P < 0.001) . The implementation of good manufacturing practices (GMP) in the stages of closure of the anus and evisceration significantly decreased the EC-count . It changed from 61.1% in carcasses without GMP that had counts higher than 1 log CFU/cm2 to only 7.4% in GMP carcasses . A final wash of the carcasses with potable water at high pressure (the only decontaminating treatment permitted in the European Union) was tested and failed to decrease the counts . It was also demonstrated that cleaning and disinfection of the dehairing and scraping machines is not effective.

Pediatrics, 2000 Dec, 106(6), 1387 - 90
Fulminant late-onset sepsis in a neonatal intensive care unit, 1988-1997, and the impact of avoiding empiric vancomycin therapy; Karlowicz MG et al.; OBJECTIVE: To determine the pathogens associated with fulminant (lethal within 48 hours) late-onset sepsis (occurring after 3 days of age) in a neonatal intensive care unit (NICU) and the frequency of fulminant late-onset sepsis for the most common pathogens . METHODS: A retrospective study was conducted of sepsis in infants in a NICU over a 10-year period (1988-1997) . RESULTS: There were 825 episodes of late-onset sepsis occurring in 536 infants . Thirty-four of 49 (69%; 95% confidence interval {CI}: 55%-82%) cases of fulminant late-onset sepsis were caused by Gram-negative organisms, including Pseudomonas sp., 20 (42%); Escherichia coli, 5 (10%); Enterobacter sp., 4 (8%); and Klebsiella sp., 4 (8%) . The frequency of fulminant sepsis was highest for Pseudomonas sp., 20 of 36 (56%; 95% CI: 38%-72%) and lowest for coagulase-negative staphylococci, 4 of 277 (1%; 95%CI: 0%-4%) . The very low frequency of fulminant sepsis caused by coagulase-negative staphylococci did not increase during the period when oxacillin was used instead of vancomycin as the empiric antibiotic for Gram-positive organisms . CONCLUSIONS: These data suggest that empiric antibiotics selected for treatment of suspected sepsis in infants >3 days old need to effectively treat Gram-negative pathogens, particularly Pseudomonas sp., because these organisms, although less frequent, are strongly associated with fulminant late-onset sepsis in the NICU . Avoiding empiric vancomycin therapy seemed to be a reasonable approach to late-onset sepsis, because of the very low frequency of fulminant sepsis caused by coagulase-negative staphylococci.

Diagn Microbiol Infect Dis, 1999 Nov, 35(3), 249 - 52
Disk diffusion susceptibility test development for the new glycylcycline, GAR-936; Jones RN; The in vitro activity of GAR-936, a new semisynthetic glycylcycline, was evaluated in comparison with two tetracyclines and the disk diffusion susceptibility test was assessed . Nearly 700 recent clinical isolates were tested by reference broth microdilution and disk diffusion (two disk contents) methods . Among the Enterobacteriaceae, GAR-936 was generally two- to 16-fold more active than other tetracyclines . All enteric bacilli MIC90 results were < or = 4 micrograms/mL; the exception being Proteus mirabilis and indole-positive Proteae (> or = 8 micrograms/mL) . GAR-936 demonstrated excellent activity against all Gram-positive cocci with Enterococcus spp . (including vancomycin-resistant isolates) inhibited at 0.25 microgram/mL (GAR-936 MIC90, 0.12 or 0.25 microgram/mL) and the oxacillin-resistant Staphylococcus aureus strains were inhibited at < or = 0.25 microgram/mL . GAR-936 demonstrated good potency against several non-fermentative bacteria, but possessed limited activity against Pseudomonas aeruginosa (MIC50, 8 micrograms/mL) . In vitro susceptibility test methods were developed (disk diffusion versus reference MIC results) and tentative breakpoints were proposed . Using susceptibility criteria of either < or = 2 or < or = 4 micrograms/mL, GAR-936 in vitro susceptibility tests demonstrated rare significant serious inter-method discords (< or = 1.2%) and an absolute agreement between test results of 92.3 to 96.2% . These results indicate that GAR-936 has potent in vitro activity against a wide range of clinically important rapidly growing pathogenic bacteria, and that this novel glycylcycline candidate for clinical use should be further developed.

Clin Infect Dis, 2000 Jan, 30(1), 35 - 40
Enterobacter cloacae bloodstream infections traced to contaminated human albumin; Wang SA et al.; In August 1996, a patient in Kansas developed an Enterobacter cloacae bloodstream infection (BSI) shortly after receiving Albuminar, a brand of human albumin . Albuminar contamination was suspected . A case-control study of patients with primary gram-negative bacterial BSIs showed that patients with E . cloacae BSIs were significantly more likely than patients with non-E . cloacae gram-negative BSIs to have received Albuminar within 3 days of developing their BSIs (3 of 5 vs . 0 of 9; OR, undefined; P=.03) . The E . cloacae isolate from the Kansas patient was found by pulsed-field gel electrophoresis to be identical to the isolate from the patient's Albuminar vial, to isolates from 2 previously unopened Albuminar vials, and to an isolate from a Wisconsin patient who had received Albuminar . A worldwide recall of approximately 116,000 Albuminar vials took place . This multistate outbreak was detected because of clinical astuteness and prompt reporting . Combined epidemiological and laboratory approaches are valuable when investigating potentially contaminated blood components and plasma derivatives.

Appl Environ Microbiol, 2000 Jan, 66(1), 125 - 32
Impact of an urban effluent on antibiotic resistance of riverine Enterobacteriaceae and Aeromonas spp; Goni-Urriza M et al.; In order to evaluate the impact of an urban effluent on antibiotic resistance of freshwater bacterial populations, water samples were collected from the Arga river (Spain), upstream and downstream from the wastewater discharge of the city of Pamplona . Strains of Enterobacteriaceae (representative of the human and animal commensal flora) (110 isolates) and Aeromonas (typically waterborne bacteria) (118 isolates) were selected for antibiotic susceptibility testing . Most of the Aeromonas strains (72%) and many of the Enterobacteriaceae (20%) were resistant to nalidixic acid . Singly nalidixic acid-resistant strains were frequent regardless of the sampling site for Aeromonas, whereas they were more common upstream from the discharge for enterobacteria . The most common resistances to antibiotics other than quinolones were to tetracycline (24.3%) and beta-lactams (20.5%) for Enterobacteriaceae and to tetracycline (27.5%) and co-trimoxazole (26.6%) for Aeromonas . The rates of these antibiotic resistances increased downstream from the discharge at similar degrees for the two bacterial groups; it remained at high levels for enterobacteria but decreased along the 30-km study zone for Aeromonas . Genetic analysis of representative strains demonstrated that these resistances were mostly (enterobacteria) or exclusively (Aeromonas) chromosomally mediated . Moreover, a reference strain of Aeromonas caviae (CIP 7616) could not be transformed with conjugative R plasmids of enterobacteria . Thus, the urban effluent resulted in an increase of the rates of resistance to antibiotics other than quinolones in the riverine bacterial populations, despite limited genetic exchanges between enterobacteria and Aeromonas . Quinolone resistance probably was selected by heavy antibiotic discharges of unknown origin upstream from the urban effluent.

Appl Environ Microbiol, 2000 Jan, 66(1), 87 - 91
Importance of pfkA for rapid growth of Enterobacter cloacae during colonization of crop seeds; Roberts DP et al.; Enterobacter cloacae A-11 is a prototrophic, glycolytic mutant of strain 501R3 with a single transposon insertion in pfkA . The populations of strain A-11 on cucumber and radish seeds were smaller than the populations of strain 501R3 in natural soil, but the populations of these two strains on pea, soybean, sunflower, and sweet corn seeds were similar (D . P . Roberts, P . D . Dery, I . Yucel, J . Buyer, M . A . Holtman, and D . Y . Kobayashi, Appl . Environ . Microbiol . 65:2513-2519, 1999) . The net effect of the mutation in pfkA in vitro was a shift from rapid growth on certain carbohydrates detected in seed exudates to much slower growth on other carbohydrates, amino acids, and organic acids . The impact of the mutation in pfkA was greatest on the growth rate of E . cloacae on the seeds that released the smallest quantities of fructose, other carbohydrates, and amino acids . Corn, pea, soybean, and sunflower seeds released total amounts of carbohydrates and amino acids at rates that were approximately 10- to 100-fold greater than the rates observed with cucumber and radish seeds for the first 24 h after inhibition began . The growth rate of strain A-11 was significantly less (50% less) than the growth rate of strain 501R3 on radish seeds, and the growth rate of strain A-11 was too low to estimate on cucumber seeds in sterile sand for the first 24 h after inhibition began . The growth rate of strain A-11 was also significantly lower on soybean seeds, but it was only 17% lower than the growth rate of strain 501R3 . The growth rates of strains 501R3 and A-11 were similar on pea, sunflower, and corn seeds in sterile sand for the first 30 h after imbibition began . Large reductions in the growth rates of strain A-11 on seeds were correlated with subsequent decreased levels of colonization of seeds compared to the levels of colonization of strain 501R3 . The strain A-11 populations were significantly smaller than the strain 501R3 populations only on radish and cucumber seeds . The mutation in pfkA appears to decrease the level of colonization by E . cloacae for seeds that release small quantities of reduced carbon compounds by decreasing the size of the pool of compounds that support rapid growth by this bacterium.

Eur J Clin Microbiol Infect Dis, 1999 Nov, 18(11), 796 - 803
Comparative evaluation of five chromogenic media for detection, enumeration and identification of urinary tract pathogens; Carricajo A et al.; Five chromogenic agar plates--CPS ID2 medium (bioMerieux, France), CHROMagar Orientation medium (Becton Dickinson, France), UriSelect3 medium (Sanofi Diagnostics Pasteur, France), Rainbow Agar UTI medium (Biolog, USA) and Chromogenic UTI medium (Oxoid, Germany)--for the detection, enumeration and direct identification of urinary tract pathogens were compared using 443 urine specimens at two hospital laboratories . The enumeration of microorganisms was consistent on the five media for 403 of the 477 (84.5%) microorganisms . Chromogenic UTI, CPS ID2, UriSelect3, CHROMagar Orientation and Rainbow UTI gave detection rates of 98.3%, 97.9%, 97.3%, 96.9% and 94.1%, respectively, with some problems in yeast growth occurring on Rainbow UTI agar and problems in Staphylococcus spp . growth occurring on UriSelect3 . For the direct identification of Escherichia coli, sensitivities were 93.8%, 88.5%, 86.1% and 82.2% for CHROMagar Orientation, CPS ID2, UriSelect3 and Rainbow UTI, respectively . Chromogenic UTI medium did not allow the accurate identification of Escherichia coli, since the indole reaction cannot be applied to this medium . Depending on the media, Enterococcus spp . could be identified at the genus or the species level . Slight differences were detected in the presumptive identification of the Proteus-Morganella-Providencia group and the Klebsiella-Enterobacter-Serratia group . Additionally, on Rainbow UTI agar, 12 of 20 Klebsiella pneumoniae strains and two of nine Pseudomonas aeruginosa strains were correctly identified . In conclusion, CPS ID2 medium and CHROMagar Orientation medium showed similar performance overall, while the UriSelect3, Rainbow UTI and Chromogenic UTI media require some improvement.

Infect Control Hosp Epidemiol, 1999 Dec, 20(12), 816 - 20
Evidence of nosocomial Stenotrophomonas maltophilia cross-infection in a neonatology unit analyzed by three molecular typing methods; Garcia de Viedma D et al.; OBJECTIVE: To characterize the epidemiological relationships among Stenotrophomonas maltophilia isolates in the neonatology unit of our institution over a 4-month period in which an increased number of isolates was observed . SETTING: The neonatology ward in a 2,000-bed university hospital in Madrid, Spain . DESIGN: A retrospective molecular epidemiological analysis using three different typing methods, arbitrarily primed polymerase chain reaction (PCR), pulsed-field gel electrophoresis, and enterobacterial repetitive intergenic consensus-PCR, was performed with 11 isolates obtained from seven neonates over a 4-month period . Presumed unrelated isolates also were included as controls . A similarity dendrogram was obtained, to analyze the genetic relatedness among the isolates . RESULTS: All isolates from the neonates, except one, showed a remarkably high homology among their typing patterns for the three methods assayed and clustered in the relatedness dendrogram at 96% similarity . The unrelated strains selected as controls were unclustered . The index case was considered to be a newborn who had an S . maltophilia isolate from a culture drawn on the day of admission to the neonatology unit and which was included in the clustered similarity group . CONCLUSIONS: Such a high genetic similarity among the isolates, together with the presence of an index case who had been colonized or infected by S . maltophilia before arrival at our institution, constitutes the first evidence of nosocomial cross-transmission of this microorganism.

Salud Publica Mex, 1999, 41 Suppl 1, S32 - 7
{Control of pediatric nosocomial bacteremia by a program based on culturing of parenteral solutions in use}; Munoz JM et al.; OBJECTIVE: As Klebsiella, Enterobacter and Serratia are capable of growth in i.v . fluids and these bacteria are commonly implicated in nosocomial bacteremia, a control strategy through microbiological surveillance of in-use parenteral solutions is proposed . MATERIAL AND METHODS: A second level general teaching hospital, serving low-income patients . Through four consecutive strategies, a continuous surveillance program of i.v . fluids sterility in pediatric wards was stablished in 1992 . During the first stage all of the in-use solutions were cultured . During the second stage randomly selected samples were studied . Third stage was designed as a case-control study . The last stage included samples drawn in convenience . Positive cultures point out eventual infusion mishandling, as well as high-risk areas and patients . RESULTS: After culturing 1940 parenteral solutions, infusion contamination rates decreased from 29.6% in 1992 to 12.9% in 1997 (p < 0.001) . The proportion of Gram-negative rods isolated from blood cultures went from 72.7% to 40.85% (p < 0.0001), and the nosocomial bacteremia rate dropped from 3.12 to 1.54 per 100 discharges . CONCLUSIONS: The program has enabled us to: 1) Detect and control eventual bacteremia outbreaks; 2) Assess the endemic infusion contamination rate; 3) Arouse healthcare workers awareness about infusion line precautions; 4) Have a suitable surveillance strategy according to our laboratory's workload.

J Food Prot, 1999 Dec, 62(12), 1488 - 96
Impedance microbiology: applications in food hygiene; Wawerla M et al.; Impedance microbiology is a rapid method that enables qualitative and quantitative tracing of microorganisms by measuring the change in the electrical conductivity . With direct impedance technology, the change in the conductivity of a liquid culture medium serves as a measuring parameter, whereas with indirect impediometry, the change in the electrical conductivity of a reaction solution, which occurs through the absorption of gases from the inoculated bacterial culture, is measured . Most investigations concerning the applicability of impediometry in food microbiology deal with the impedimetric detection or enumeration of Enterobacteriaceae, especially the detection of Salmonella . However, impediometry has been applied to other bacterial groups or species as well . Furthermore, a great number of published findings concern the impedimetric determination of the total bacterial count . The successful application of this fast method on further areas of food hygiene, such as tracing antibiotics and testing additives for their antimicrobiological effect, has also been described . In general the use of impediometry for the application areas stated has been judged positively . However, the time and expense required by the user to optimize the method, the deficits when testing slightly contaminated sample material or determining the bacterial count in those cases in which the microorganisms are sublethally damaged, and the necessity of performing individual calibration for each food category limit the applicability of impediometry.

J Food Prot, 1999 Dec, 62(12), 1411 - 5
Microbiological changes in pressurized, prepackaged sliced cooked ham; Lopez-Caballero ME et al.; This was a study of the influence of high-pressure conditions (200 and 400 MPa, 5 and 20 min, 7 degrees C) on microbiological quality and water-binding properties of vacuum-prepackaged sliced cooked ham and how this affects microbiological changes during chilled storage (2 degrees C) . Pressurization caused a degree of microbiological inactivation, which increased with pressure level and processing time . Pressurization at 400 MPa significantly reduced the total viable count and lactic acid bacteria to the extent that after 20 min no Enterobacteriaceae, Baird Parker flora, or Brochothrix thermosphacta were detected throughout any of the chilled storage periods studied . In general, gram-positive flora was more resistant to pressure than gram-negative flora . The fact that high pressure (400 MPa) causes considerable inactivation of microorganisms could be used to prolong the shelf life of vacuum-prepackaged sliced cooked ham.

Antimicrob Agents Chemother, 2000 Jan, 44(1), 213 - 6
Production of a TEM-24 plasmid-mediated extended-spectrum beta-lactamase by a clinical isolate of Pseudomonas aeruginosa; Marchandin H et al.; Several Pseudomonas aeruginosa strains, including one urinary isolate producing an extended-spectrum beta-lactamase TEM-24, were isolated from a long-term-hospitalized woman . Three TEM-24-producing enterobacterial species (Enterobacter aerogenes, Escherichia coli, and Proteus mirabilis) were isolated from the same patient . TEM-24 and the resistance markers for aminoglycosides, chloramphenicol, and sulfonamide were encoded by a 180-kb plasmid transferred by conjugation into E . coli HB101.

Antimicrob Agents Chemother, 2000 Jan, 44(1), 169 - 72
Role of penicillin-binding proteins in the initiation of the AmpC beta-lactamase expression in Enterobacter cloacae; Pfeifle D et al.; Penicillin-binding proteins (PBPs) are involved in the regulation of beta-lactamase expression by determining the level of anhydromuramylpeptides in the periplasmatic space . It was hypothesized that one or more PBPs act as a sensor in the beta-lactamase induction pathway . We have performed induction studies with Escherichia coli mutants lacking one to four PBPs with DD-carboxypeptidase activity . Therefore, we conclude that a strong beta-lactamase inducer must inhibit all DD-carboxypeptidases as well as the essential PBPs 1a, 1b, and/or 2.

Protein Expr Purif, 1999 Dec, 17(3), 366 - 72
Molecular cloning of the arylsulfate sulfotransferase gene and characterization of its product from Enterobacter amnigenus AR-37; Kwon AR et al.; The gene encoding the Enterobacter amnigenus AR-37 arylsulfate sulfotransferase (ASST) was cloned, sequenced, and expressed in Escherichia coli NM522 . Sequencing led to the identification of three contiguous open reading frames (ORFs) on the same strand . Based on amino acid sequence homology, ORF1, ORF2, and ORF3 are designated astA, dsbA, and dsbB, respectively . A multiple sequence alignment revealed conserved regions in ASST . An N-terminal amino acid sequence analysis of the purified ASST from E . coli NM522 (pEAST72) showed that it is subject to N-terminal processing . The specific activity of purified ASST is 436.5 U/mg of protein . The enzyme is a monomeric protein with a molecular mass of 64 kDa . Using phenol as an acceptor substrate, 4-methylumbelliferyl sulfate is the best donor substrate, followed by beta-naphthyl sulfate, p-nitrophenyl sulfate (PNS), and alpha-naphthyl sulfate . For PNS, alpha-naphthol is the best acceptor substrate, followed by phenol, resorcinol, p-acetaminophen, tyramine, and tyrosine . The enzyme has a different acceptor specificity than the enzyme purified from Eubacterium A-44 . It is similar to Klebsiella K-36 and Haemophilus K-12 . The apparent K(m) values for PNS using phenol as an acceptor and for phenol using PNS as a donor are 0.163 and 0.314 mM, respectively . The pI and optimum pH are 6.1 and 9.0, respectively .

J Mol Biol, 1999 Dec 17, 294(5), 1401 - 11
Intramolecular signal transmission in enterobacterial aspartate transcarbamylases II . Engineering co-operativity and allosteric regulation in the aspartate transcarbamylase of Erwinia herbicola; Cunin R et al.; The aspartate transcarbamylase (ATCase) from Erwinia herbicola differs from the other investigated enterobacterial ATCases by its absence of homotropic co-operativity toward the substrate aspartate and its lack of response to ATP which is an allosteric effector (activator) of this family of enzymes . Nevertheless, the E . herbicola ATCase has the same quaternary structure, two trimers of catalytic chains with three dimers of regulatory chains ((c3)2(r2)3), as other enterobacterial ATCases and shows extensive primary structure conservation . In (c3)2(r2)3 ATCases, the association of the catalytic subunits c3 with the regulatory subunits r2 is responsible for the establishment of positive co-operativity between catalytic sites for the binding of aspartate and it dictates the pattern of allosteric response toward nucleotide effectors . Alignment of the primary sequence of the regulatory polypeptides from the E . herbicola and from the paradigmatic Escherichia coli ATCases reveals major blocks of divergence, corresponding to discrete structural elements in the E . coli enzyme . Chimeric ATCases were constructed by exchanging these blocks of divergent sequence between these two ATCases . It was found that the amino acid composition of the outermost beta-strand of a five-stranded beta-sheet in the effector-binding domain of the regulatory polypeptide is responsible for the lack of co-operativity and response to ATP of the E . herbicola ATCase . A novel structural element involved in allosteric signal recognition and transmission in this family of ATCases was thus identified .

J Heart Lung Transplant, 1999 Nov, 18(11), 1103 - 10
Development of an infection-resistant LVAD driveline: a novel approach to the prevention of device-related infections; Choi L et al.; BACKGROUND: Infection remains the single most important challenge to extended left ventricular assist device (LVAD) use and often arises from the percutaneous driveline exit site . We evaluated the ability of an LVAD driveline prototype impregnated with chlorhexidine, triclosan, and silver sulfadiazine to resist bacterial and fungal colonization . METHODS: The spectrum and duration of antimicrobial activity were evaluated in vitro by daily transfer of driveline segments embedded on agar plates inoculated with 10(8) colony-forming units (CFU) of Staphylococcus aureus (S . aureus), Staphlococcus epidermidis, Enterobacter aerogenes, Psuedomonas aeruginosa, and Candida albicans, and then measuring zones of inhibition around the sample subsequent to 24 hours of incubation at 37 degrees C . Antimicrobial activity was demonstrated against all organisms for greater than 14 days, and for over 21 days for gram-positive bacteria . To demonstrate in vivo efficacy of the treated driveline, 3-cm segments of driveline were implanted in the dorsal and ventral surface of rats . The exit site was inoculated with 10(6) CFU of S . aureus . After 7 days, driveline segments were aseptically explanted and assayed for bacterial colonization and retention of antimicrobial activity . One hundred percent of control segments were colonized (10(5) CFU S . aureus/cm) as against 13% of the test explants (< or = 330 CFU/cm; p < 0.0001) . RESULTS: Subcultures of the insertion site and driveline pocket tissue resulted in 10(3) to 10(5) CFU per swab culture for control rats and 0 to 10(2) CFU/swab for test animals . Test drivelines retained 80% of anti-S . aureus activity . Gross and histological examination of the driveline and surrounding pocket revealed minimal tissue reactivity with positive signs of tissue ingrowth . CONCLUSION: An antimicrobial driveline may prevent early infections and facilitate ingrowth of tissue to provide long-term stability and protection against late infection.

Int J Food Microbiol, 1999 Dec 1, 53(1), 33 - 41
Improved screening procedure for biogenic amine production by lactic acid bacteria; Bover-Cid S et al.; An improved screening plate method for the detection of amino acid decarboxylase-positive microorganisms (especially lactic acid bacteria) was developed . The suitability and detection level of the designed medium were quantitatively evaluated by confirmation of amine-forming capacity using an HPLC procedure . The potential to produce the biogenic amines (BA) tyramine, histamine, putrescine, and cadaverine, was investigated in a wide number of lactic acid bacteria (LAB) of different origin, including starter cultures, protective cultures, type strains and strains isolated from different food products . Also, several strains of Enterobacteriaceae were examined . Modifications to previously described methods included lowering glucose and sodium chloride concentrations, and increasing the buffer effect with calcium carbonate and potassium phosphate . In addition, pyridoxal-5-phosphate was included as a codecarboxylase factor for its enhancing effect on the amino acid decarboxylase activity . The screening plate method showed a good correlation with the chemical analysis and due to its simplicity it is presented as a suitable and sensitive method to investigate the capacity of biogenic amine production by LAB . Tyramine was the main amine formed by the LAB strains investigated . Enterococci, carnobacteria and some strains of lactobacilli, particularly of Lb . curvatus . Lb . brevis and Lb . buchneri, were the most intensive tyramine formers . Several strains of lactobacilli, Leuconostoc spp., Weissella spp . and pediococci did not show any potential to produce amines . Enterobacteriaceae were associated with cadaverine and putrescine formation . No significant histamine production could be detected for any of the strains tested.

Ther Umsch, 1999 Nov, 56(11), 640 - 6
{Meningitis (II)--acute bacterial meningitis}; Leib SL et al.; Acute meningitis is a medical emergency, particularly in patients with rapidly progressing disease, mental status changes or neurological deficits . The majority of cases of bacterial meningitis are caused by a limited number of species, i.e . Streptococcus pneumoniae, Neisseria meningitis, Listeria monocytogenes, group B Streptococci (Streptococcus agalactiae), Haemophilus influenzae and Enterobacteriaceae . Many other pathogens can occasionally cause bacterial meningitis, often under special clinical circumstances . Treatment of meningitis includes two main goals: Eradication of the infecting organism, and management of CNS and systemic complications . Empiric therapy should be initiated without delay, as the prognosis of the disease depends on the time when therapy is started . One or two blood cultures should be obtained before administering the first antibiotic . Empiric therapy is primarily based on the age of the patient, with modifications if there are positive findings on CSF gram stain or if the patient presents with special risk factors . It is safer to choose regimens with broad coverage, as they can usually be modified within 24-48 hours, when antibiotic sensitivities of the infecting organism become available . Adjunctive therapy with dexamethasone is also administered in severely ill patients concomitantly with the first antibiotic dose . In patients who are clinically stable and are unlikely to be adversely affected if antibiotics are not administered immediately, including those with suspected viral or chronic meningitis, a lumbar puncture represents the first step, unless there is clinical suspicion of an intracerebral mass lesion . Findings in the CSF and on CT scan, if performed, will guide the further diagnostic work-up and therapy in all patients.

Drugs, 1999, 58 Suppl 2, 85 - 91
Use of quinolones in osteomyelitis and infected orthopaedic prosthesis; Lew DP et al.; The present review provides an updated critical analysis of the use of quinolones in osteomyelitis and orthopaedic prosthetic infections . Only papers published in peer-reviewed journals and related to the following areas were selected: experimental osteomyelitis, penetration of quinolones into human bone, and clinical use in comparative and noncomparative studies . Local drug carriers impregnated with quinolones allow high local antibiotic concentrations to be achieved in experimental systems . Considerable clinical experience has been gained mostly with ciprofloxacin and ofloxacin . Cumulated results in clinical trials show clinical success rates of more than 90% in osteomyelitis caused by Enterobacteriaceae . The combination of quinolones and rifampicin for the treatment of staphylococcal osteomyelitis as well as orthopaedic prosthetic infections appears very promising in clinical studies with a small number of patients . However, further comparative studies using quinolones as single agents or in combination (versus standard parenteral therapy) remain necessary in osteomyelitis due to Staphylococcus aureus or Pseudomonas aeruginosa . In particular, studies with the newer quinolones should be strongly encouraged in acute or chronic osteomyelitis and in more complicated situations such as diabetic osteomyelitis or foreign-body infection.

Drugs, 1999, 58 Suppl 2, 65 - 70
Effect of quinolones on intestinal ecology; Edlund C et al.; Quinolones have a selective effect on the normal human intestinal microflora . Published data on 13 different quinolone agents {ciprofloxacin, enoxacin, norfloxacin, ofloxacin, pefloxacin, lomefloxacin, levofloxacin, sparfloxacin, rufloxacin, sitafloxacin (DU-6859a), gatifloxacin, trovafloxacin and moxifloxacin} show that gram-negative aerobic bacteria, especially Enterobacteriaceae, are strongly suppressed or eliminated during therapy . Gram-positive aerobic cocci are affected strongly by administration of sitafloxacin and moxifloxacin and to minor degrees by the other quinolones . Three new quinolones--gatifloxacin, trovafloxacin and moxifloxacin--are very active against anaerobic bacteria in vitro but have minor effects on the anaerobic intestinal human microflora . Similar findings have been reported for the other 10 quinolones . Thus, the quinolone antibacterials have an ecological impact on the human intestinal microflora, mainly on the enterobacteria, that should be taken into account when these agents are used for prophylaxis or treatment of gastrointestinal bacterial infections.

Syst Appl Microbiol, 1999 Sep, 22(3), 321 - 8
Molecular characterisation of the dnaK operon of Lactobacillus sakei LTH681; Schmidt G et al.; The use of lactobacilli as starter organisms in food fermentation processes requires thorough knowledge of their reaction to the multitude of ecological factors including their response to stress . We have characterised the dnaK gene region of Lactobacillus sakei LTH681 . Two chromosomal EcoRI fragments of 2.5 and 4.0 kb were identified using a homologous dnaK probe generated by PCR . The sequence analysis of the cloned fragments showed that the dnaK gene region consists of four heat shock genes with the organisation hrcA-grpE-dnaK-dnaJ . Comparison of the deduced amino acid sequences revealed high similarity to the corresponding heat shock proteins of Gram-positive bacteria . An upstream located orfY was found which exhibited substantial similarity (41.5%) to the chloramphenicol acetyltransferase of Enterobacter aerogenes . Northern hybridisation analysis revealed that the transcription of the genes is induced by heat shock (42 degrees C) as well as salt (6%) or ethanol (10%) stress . Several transcripts were detected including a polycistronic mRNA of 4.9 kb which represents the transcript of the complete dnaK gene region indicating a tetracistronic organisation of the dnaK operon . The other RNA fragments were identified as shorter transcripts (3.7 and 1.3 kb) or cleavage products of the polycistronic mRNAs . The transcription start sites of the dnaK operon were determined under inducing and non-inducing conditions . The site varied with the applied stress condition . A regulatory CIRCE element was identified located between the transcription and translation start site . The promoter region including CIRCE was transcriptionally fused to the beta-glucuronidase reporter gene gusA and expressed in L . sakei LTH681 . The kinetics of transcriptional induction of gusA by heat shocking were identical to those of the dnaK operon confirming the involvement of the CIRCE element in regulation of gene expression.

J Antimicrob Chemother, 1999 Nov, 44(5), 679 - 88
The in-vitro activity and tentative breakpoint of gemifloxacin, a new fluoroquinolone; Wise R et al.; The in-vitro activity of gemifloxacin, a new fluoroquinolone, against a wide range (c . 700) of recent clinical isolates, was compared with that of three other fluoroquinolones and other relevant agents . Gemifloxacin inhibited 90% of the Enterobacteriaceae strains at 0.5 mg/L or less, exceptions being Serratia spp . (MIC(90) 1 mg/L) and strains possessing a putative mechanism of resistance to fluoroquinolones . Ninety per cent of Pseudomonas aeruginosa were inhibited by 4 mg/L . Gemifloxacin had good activity against respiratory pathogens, with 90% of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis being inhibited by 0.06 mg/L or less . Staphylococcus aureus (MSSA) were highly susceptible (MIC(90) 0.06 mg/L) but MRSA less susceptible (MIC(90) 8 mg/L) to gemifloxacin . Enterococcus spp . were markedly more susceptible to the study agent than to ciprofloxacin . Gemifloxacin showed good activity against Bacteroides fragilis (MIC(90) 0.5 mg/L) and anaerobic cocci . A tentative in-vitro breakpoint of 0.5 mg/L was studied using a 1 microg disc content for all genera except Pseudomonas where a 5 microg disc content was employed . The false sensitivity reporting rate was 0.5% and false resistance rate was 6.0%, which was considered acceptable . In conclusion, gemifloxacin is a highly active fluoroquinolone that should prove clinically useful in the treatment of a wide range of infections . Susceptibility testing criteria have been developed that should prove robust in a clinical laboratory.

J Antimicrob Chemother, 1999 Nov, 44(5), 611 - 9
New species-related MIC breakpoints for early detection of development of resistance among gram-negative bacteria in Swedish intensive care units; Hanberger H et al.; The frequency of decreased antibiotic susceptibility among 534 Gram-negative aerobic bacilli from patients admitted to intensive care units at eight hospitals in Sweden during 1997 was evaluated . MICs of cefepime, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem and piperacillin-tazobactam were determined using Etest . Reduced susceptibility (resistant and intermediate/indeterminate susceptible strains) was defined according to the MIC breakpoints of the British Society for Antimicrobial Chemotherapy (BSAC), the National Committee for Clinical Laboratory Standards (NCCLS) and the new species-related breakpoints of the Swedish Reference Group for Antibiotics (SRGA) . The BSAC/NCCLS/SRGA breakpoints for susceptible category (mg/L) of Enterobacteriaceae are: cefepime, not available (NA)/8/0.5; ceftazidime, 2/8/2; ceftriaxone, NA/8/0.5; ciprofloxacin, 1/1/0.12; gentamicin, 1/4/2; imipenem, 4/4/1; and piperacillin-tazobactam, NA/16/16 . The most frequently isolated organisms were Escherichia coli (n = 160; 30%), Klebsiella spp . (n = 84; 16%), Enterobacter spp . (n = 77; 14%), Pseudomonas aeruginosa (n = 64; 12%) andProteus spp . (n = 28; 5%) . Decreased susceptibility among E . coliusing the BSAC/NCCLS/SRGA respective breakpoints (%) were: cefepime, NA/0/2; ceftazidime, 2/2/2; ceftriaxone, NA/1/2; ciprofloxacin, 2/2/8; gentamicin, 21/0/3; imipenem, 0/0/2; and piperacillin-tazobactam, NA/4/4 . Corresponding levels of decreased susceptibility (%) among Klebsiellaspp . were: cefepime, NA/0/5; ceftazidime, 2/1/2; ceftriaxone, NA/1/10; ciprofloxacin, 4/4/19; gentamicin, 25/2/5; imipenem, 0/0/0; and piperacillin-tazobactam, NA/10/10; and among Enterobacter spp . were: cefepime, NA/1/19; ceftazidime, 30/29/30; ceftriaxone, NA/30/36; ciprofloxacin, 3/3/15; gentamicin,18/0/0; imipenem, 0/0/5; and piperacilllin-tazobactam, NA/27/27 . In conclusion, the species-related SRGA breakpoints detected Gram-negative isolates with decreased susceptibility in comparison with the native population with higher frequency than did the NCCLS breakpoints . The BSAC breakpoints for susceptible organisms were similar to NCCLS for ciprofloxacin and imipenem, and similar to SRGA for ceftazidime but lower than both NCCLS and SRGA for gentamicin, causing a much higher frequency of decreased susceptibility to gentamicin.

J Appl Microbiol, 1999 Nov, 87(5), 770 - 81
Evaluation of phenotypic and molecular typing techniques for determining diversity in Erwinia carotovora subspp . atroseptica; Toth IK et al.; A number of phenotypic and molecular fingerprinting techniques, including physiological profiling (Biolog), restriction fragment length polymorphism (RFLP), enterobacterial repetitive intergenic consensus (ERIC) and a phage typing system, were evaluated for their ability to differentiate between 60 strains of Erwinia carotovora ssp . atroseptica (Eca) from eight west European countries . These techniques were compared with other fingerprinting techniques, random amplified polymorphic DNA (RAPD) and Ouchterlony double diffusion (ODD), previously used to type this pathogen . Where possible, data were represented as dendrograms and groups/subgroups of strains identified . Simpson's index of diversity (Simpson's D) was used to compare groupings obtained with the different techniques which, with the exception of Biolog, gave values of 0.46 (RFLP), 0 . 39 (ERIC), 0.83 (phage typing), 0.82 (RAPD) and 0.26 (ODD) . Of the techniques tested, phage typing showed the highest level of diversity within Eca, and this technique will now form the basis of studies into the epidemiology of blackleg disease.

Dermatol Surg, 1999 Nov, 25(11), 857 - 61
Cutaneous CO2 laser resurfacing infection rate with and without prophylactic antibiotics; Walia S et al.; BACKGROUND: Cutaneous laser resurfacing is a well-accepted modality, with excellent clinical outcomes and low morbidity rates, for the treatment of a variety of epidermal and dermal lesions . The use of antibiotic prophylaxis continues to be an area of controversy, with laser practitioners divided in their approach . OBJECTIVE: To identify the rate of postoperative bacterial infection following full-face carbon dioxide (CO2) laser resurfacing with and without antibiotic prophylaxis . METHODS: A retrospective chart review of 133 consecutive patients following full-face CO2 laser resurfacing was performed . The rate, severity, duration, and subsequent treatment of bacterial infections observed in four treatment categories were recorded: (1) no antibiotic prophylaxis; (2) intraoperative single-dose intravenous cephalexin (1 g); (3) postoperative oral azithromycin (1.5 g over 5 days); (4) intraoperative IV cephalexin (1 g) and postoperative oral azithromycin (1.5 g) . RESULTS: A significantly higher rate of infection occurred in patients receiving combination intraoperative and/or postoperative antibiotic prophylaxis . The most frequently cultured organisms included Enterobacter and Pseudomonas species . CONCLUSION: The rate of postoperative bacterial infections after full-face CO2 laser resurfacing in this retrospective study was not significantly reduced with the use of prophylactic antibiotics.

Curr Pharm Des, 1999 Nov, 5(11), 865 - 79
OXA-type beta-lactamases; Naas T et al.; The OXA-type (oxacillin-hydrolysing) enzymes are widespread and have been mostly described in Enterobacteriaceae and in P . aeruginosa . They usually confer resistance to amino- and ureidopenicillin and possess high-level hydrolytic activity against cloxacillin, oxacillin, and methicillin . Their activities are weakly inhibited by clavulanic acid but sodium chloride (NaCl) possesses a strong inhibition activity . Oxacillin-hydrolysing b-lactamases belong to Ambler class D and thus possess an active serine site as classes A and C b-lactamases . Overall amino-acid identities between class D and class A or class C b-lactamases is about 16% . Until now, 24 Ambler class D enzymes, named OXA-1 to OXA-22, AmpS and LCR-1, have been characterised, either by sequence and/or by biochemical analyses, but for none of them a three dimensional structure is yet available . While some oxacillinases present a significant degree of amino-acid identity (for example, OXA-1 and OXA-4; OXA-10 (PSE-2) derivatives; OXA-2 and OXA-3), most of them are only weakly related (20% to 30% amino-acid identity) . Oxacillinases usually display a restricted-spectrum phenotype . However extension of their spectrum towards oxyimino cephalosporins and/or imipenem has recently been observed mostly as a consequence of point mutations in OXA-2 or OXA-10 derivatives . Their frequent plasmid- and/or integron-location provide them a mean for a wide diffusion.

Curr Pharm Des, 1999 Nov, 5(11), 847 - 64
SHV-type beta-lactamases; Tzouvelekis LS et al.; The group of plasmid-mediated SHV b-lactamases includes SHV-1 and at least twenty-three variants, most of which possess extended-spectrum (ES) activity against the newer broad-spectrum cephalosporins . Their likely ancestor is a chromosomal penicillinase of Klebsiella pneumoniae . SHV enzymes belong to the molecular class A of serine b-lactamases and share extensive functional and structural similarity with TEM b-lactamases . The three-dimensional structure of the SHV-1 b-lactamase possesses an active site wider than that of TEM-1 b-lactamase by 0.7 to 1.2 A . This results in subtle, yet important, differences in the positioning of critical active-site residues . SHV-1 b-lactamase behaves as a typical penicillinase hydrolyzing penicillins and early generation cephalosporins . SHV-1 b-lactamase has spread, via plasmids, to virtually all enterobacterial species but is encountered mostly in K . pneumoniae . ES SHV b-lactamases are found with increasing frequency in K . pneumoniae and other enterobacterial isolates and are now considered the most prevalent ES b-lactamases . These ES SHV b-lactamases confer a wide spectrum of resistance to b-lactams, including the new generation cephalosporins and monobactams, and are usually encoded by self-transmissible multi-resistant plasmids that are highly mobile . Extension of the hydrolytic spectrum of ES SHV enzymes to include oximino-b-lactams is seen as a result of substitutions of critical amino acid residues that alter the properties of the active site . These mutational changes, however, result in diminished hydrolytic activity against penicillins and an increased susceptibility to mechanism-based inhibitors . Understanding the substrate evolution, properties and modes of spread of these clinically important b-lactamases can help in formulating effective antibiotic policies and developing new antimicrobial agents.

J Antimicrob Chemother, 1999 Dec, 44(6), 819 - 22
Tentative minimum inhibitory concentration and zone diameter breakpoints for moxifloxacin using BSAC criteria; Andrews JM et al.; Tentative MIC and zone diameter breakpoints were determined for moxifloxacin using BSAC criteria . An MIC breakpoint of < or =1 mg/L, denoting sensitivity, is suggested for Enterobacteriaceae, staphylococci, haemophili, moraxellae, pneumococci and enterococci . For pseudomonads high and low breakpoints of 4 mg/L and 1 mg/L are suggested to allow for an intermediate category of sensitivity . A 1 microg moxifloxacin disc content is suggested for testing all of the organisms previously mentioned, except pseudomonads, for which a 5 microg disc is needed to discriminate between the intermediate and sensitive populations . Corresponding zone diameter breakpoints for a 1 microg disc are > or = 20 mm for Enterobacteriaceae and staphylococci, 18 mm for the respiratory pathogens (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis) and 15 mm for enterococci . For Pseudomonas aeruginosa with a 5 microg disc, three bands are suggested for interpretation, that of > or = 25 mm (sensitive), 18-24 mm (intermediate) and < or = 17 mm (resistant).

J Med Entomol, 1999 Nov, 36(6), 888 - 91
Reservoir competence of Carcinops pumilio for Salmonella enteritidis (Eubacteriales: Enterobacteriaceae); Gray JP et al.; The histerid beetle Carcinops pumilio (Erichson) occurs naturally in poultry house manure and is an important predator of house fly eggs and larvae . Because efforts to commercially produce C . pumilio have been unsuccessful, one fly control strategy under consideration is the direct transport of adult C . pumilio between poultry houses to facilitate their establishment . However, we demonstrate that C . pumilio is a competent reservoir of Salmonella enteritidis (Gaertner) . Adult C . pumilio exposed to S . enteritidis-inoculated house fly eggs harbored the bacterium externally and internally for up to 4 and 13 d, respectively, and feces were culture-positive for S . enteritidis for at least 14 d . This suggests that C . pumilio can be a reservoir of S . enteritidis; therefore its movement between poultry facilities should be carefully considered.

Stomatologiia (Mosk), 1999, 78(6), 4 - 8
{An experimental study of the patterns in the development of an inflammatory process in the mandibular bone tissue caused by exposure to anaerobic microflora}; Pankratov AS et al.; Inflammatory process in mandibular bone was induced in 39 outbred rats by a pure culture of Bacteroides fragilis and by an associative culture of B . fragilis and Staphylococcus aureus . Anaerobic microflora notably aggravated the course of inflammation . In contrast to inflammation in other parts of the skeleton, inflammation of the jaws involves a high risk of infection of the oral cavity by pathogenic microflora . A variety of microorganisms is isolated from the focus: from gram-positive staphylococci to gram-negative enterobacteria, which fact should be borne in mind when planning antibiotic therapy . Combined use of antibiotics active towards the entire spectrum of agents detected in this study is the most effective.

Clin Infect Dis, 1999 Dec, 29(6), 1411 - 8
Control of a prolonged outbreak of extended-spectrum beta-lactamase-producing enterobacteriaceae in a university hospital; Lucet JC et al.; Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLPE) were isolated from clinical specimens from 130 to 140 patients/year in 1989-1991 in our hospital . In February 1992, a control program was initiated: screening tests in 3 intensive care units (ICUs) and contact-isolation precautions in all units . The septic surgical unit served as an isolation ward for surgical patients from whom ESBLPE was isolated . In 1992, the incidence of ESBLPE acquisition failed to decrease, and most acquisitions occurred in 3 ICUs . Critical evaluation of implementation of isolation procedures in these ICUs prompted corrective measures for barrier precautions . The incidence of acquired cases subsequently decreased, and a second evaluation determined that these measures had been correctly applied . The incidence of acquired cases in the septic surgical unit was lower than those in the other units . Decreases were also found in the incidence of acquisition of other hand-transmitted multidrug-resistant organisms . Barrier precautions, screening tests for ICU patients, and grouping of cohorts after ICU discharge are effective in controlling the spread of multidrug-resistant microorganisms by cross-contamination . The outbreak was effectively controlled without restricting antimicrobial use.

Mem Inst Oswaldo Cruz, 1999 Nov-Dec, 94(6), 795 - 802
Evidences of gentamicin resistance amplification in Klebsiella pneumoniae isolated from faeces of hospitalized newborns; Barros JC et al.; The intestinal microbiota, a barrier to the establishment of pathogenic bacteria, is also an important reservoir of opportunistic pathogens . It plays a key role in the process of resistance-genes dissemination, commonly carried by specialized genetic elements, like plasmids, phages, and conjugative transposons . We obtained from strains of enterobacteria, isolated from faeces of newborns in a university hospital nursery, indication of phenotypical gentamicin resistance amplification (frequencies of 10(-3) to 10(-5), compatible with transposition frequencies) . Southern blotting assays showed strong hybridization signals for both plasmidial and chromosomal regions in DNA extracted from variants selected at high gentamicin concentrations, using as a probe a labeled cloned insert containing aminoglycoside modifying enzyme (AME) gene sequence originated from a plasmid of a Klebsiella pneumoniae strain previously isolated in the same hospital . Further, we found indications of inactivation to other resistance genes in variants selected under similar conditions, as well as, indications of co-amplification of other AME markers (amikacin) . Since the intestinal environment is a scenario of selective processes due to the therapeutic and prophylactic use of antimicrobial agents, the processes of amplification of low level antimicrobial resistance (not usually detected or sought by common methods used for antibiotic resistance surveillance) might compromise the effectiveness of antibiotic chemotherapy.

J Antimicrob Chemother, 1999 Oct, 44(4), 483 - 8
Aminoglycoside resistance in Gram-negative blood isolates from various hospitals in Belgium and the Grand Duchy of Luxembourg . Aminoglycoside Resistance Study Group; Vanhoof R et al.; A total of 1102 consecutive clinical blood isolates, including 897 Enterobacteriaceae and 205 non-fermenting bacilli, were obtained from 13 university and university-affiliated hospitals, which were divided into a Northern and a Southern group . Resistance to gentamicin, tobramycin, netilmicin, amikacin and isepamicin was determined using a microdilution technique according to NCCLS procedures . The overall mean resistance level was 5.9% for gentamicin, 7.7% for tobramycin, 7.5% for netilmicin, 2.8% for amikacin and 1.2% for isepamicin . Resistance to amikacin and isepamicin was significantly higher in the Northern hospitals than in the Southern hospitals . In total, 157 isolates were found not to be susceptible to aminoglycosides . By PCR, 179 aminoglycoside resistance mechanisms, i.e . 150 genes encoding modifying enzymes and 29 permeability mechanisms, were detected in 148 isolates . A resistance mechanism could not be detected in nine isolates . Moreover, in a further 14 isolates the resistance profile was not fully explained by the detected genes . The aac(6')-I genes were found to be the most predominant resistance mechanism in both the Northern and Southern isolates, followed by aac(3) genes and permeability resistance . A total of 29 non-susceptible isolates harboured a combination of genes, 72.4% of which were a combination with the aac(6')-lb gene . The majority of these combinations were broad-spectrum combinations which represented 9.0% of the resistance mechanisms in non-susceptible Enterobacteriaceae and 19.3% in the non-fermenting bacilli.

Eur J Clin Microbiol Infect Dis, 1999 Oct, 18(10), 743 - 7
Cefotaxime-hydrolysing beta lactamases in Morganella morganii; Power P et al.; The frequency of enterobacterial isolates with high resistance to expanded-spectrum beta-lactam antibiotics (mainly cefotaxime or ceftriaxone) has increased notoriously in Argentina, mainly because of the spread of extended-spectrum beta-lactamases . The aim of this work was the study of extended-spectrum beta-lactamases in several Morganella morganii isolates with unusually high resistance to ceftriaxone . These strains produced at least two beta-lactamases, of apparent pIs of 5.4 and 8.2, molecular weight 23 000, well inhibited by clavulanate, compatible with a broad-spectrum beta-lactamase - perhaps TEM-1 - and an extended-spectrum beta-lactamase, respectively . The extended-spectrum beta-lactamase was identified as a CTX-M-type beta-lactamase - probably CTX-M-2 - by polymerase chain reaction, restriction profile analysis and DNA-DNA hybridisation . The remaining isolates studied produced either the broad-spectrum beta-lactamase plus the ubiquitous AmpC beta-lactamase (13 strains), or the AmpC beta-lactamase only (10 strains).

Appl Environ Microbiol, 1999 Dec, 65(12), 5464 - 73
Polyphasic study of the spatial distribution of microorganisms in Mexican pozol, a fermented maize dough, demonstrates the need for cultivation-independent methods to investigate traditional fermentations; Ampe F et al.; The distribution of microorganisms in pozol balls, a fermented maize dough, was investigated by a polyphasic approach in which we used both culture-dependent and culture-independent methods, including microbial enumeration, fermentation product analysis, quantification of microbial taxa with 16S rRNA-targeted oligonucleotide probes, determination of microbial fingerprints by denaturing gradient gel electrophoresis (DGGE), and 16S ribosomal DNA gene sequencing . Our results demonstrate that DGGE fingerprinting and rRNA quantification should allow workers to precisely and rapidly characterize the microbial assemblage in a spontaneous lactic acid fermented food . Lactic acid bacteria (LAB) accounted for 90 to 97% of the total active microflora; no streptococci were isolated, although members of the genus Streptococcus accounted for 25 to 50% of the microflora . Lactobacillus plantarum and Lactobacillus fermentum, together with members of the genera Leuconostoc and Weissella, were the other dominant organisms . The overall activity was more important at the periphery of a ball, where eucaryotes, enterobacteria, and bacterial exopolysacharide producers developed . Our results also showed that the metabolism of heterofermentative LAB was influenced in situ by the distribution of the LAB in the pozol ball, whereas homolactic fermentation was controlled primarily by sugar limitation . We propose that starch is first degraded by amylases from LAB and that the resulting sugars, together with the lactate produced, allow a secondary flora to develop in the presence of oxygen . Our results strongly suggest that cultivation-independent methods should be used to study traditional fermented foods.

Appl Environ Microbiol, 1999 Dec, 65(12), 5357 - 63
Utilization of heterologous siderophores enhances levels of iron available to Pseudomonas putida in the rhizosphere; Loper JE et al.; Pseudomonas spp . have the capacity to utilize siderophores produced by diverse species of bacteria and fungi, and the present study was initiated to determine if siderophores produced by rhizosphere microorganisms enhance the levels of iron available to a strain of Pseudomonas putida in this natural habitat . We used a previously described transcriptional fusion (pvd-inaZ) between an iron-regulated promoter (pvd) and the ice nucleation reporter gene (inaZ) to detect alterations in iron availability to P . putida . Ice nucleation activity (INA) expressed from the pvd-inaZ fusion by P . putida N1R or N1R Pvd(-), a derivative deficient in the production of a pyoverdine siderophore, was inversely related to the concentration of ferric citrate in a culture medium . In culture, INA expressed by N1R Pvd(-) (pvd-inaZ) was reduced in the presence of the ferric complex of pseudobactin-358, a pyoverdine siderophore produced by P . putida WCS358 that can be utilized as a source of iron by N1R Pvd(-) . In the rhizosphere of cucumbers grown in sterilized soil, N1R Pvd(-) (pvd-inaZ) expressed INA, indicating that iron availability was sufficiently low in that habitat to allow transcription of the iron-regulated pvd promoter . Coinoculation with WCS358 or N1R significantly decreased INA expressed by N1R Pvd(-) (pvd-inaZ) in the rhizosphere, whereas coinoculation with a pyoverdine-deficient mutant of WCS358 did not reduce INA expressed by N1R Pvd(-) (pvd-inaZ) . These results indicate that iron availability to N1R Pvd(-) (pvd-inaZ) in the rhizosphere was enhanced by the presence of another strain of P . putida that produces a pyoverdine that N1R Pvd(-) (pvd-inaZ) was able to utilize as a source of iron . In culture, strain N1R Pvd(-) also utilized ferric complexes of the siderophores enterobactin and aerobactin as sources of iron . In the rhizosphere of cucumbers grown in sterilized soil, INA expressed by N1R Pvd(-) (pvd-inaZ) was reduced in the presence of strains of Enterobacter cloacae that produced enterobactin, aerobactin, or both siderophores, but INA expressed by N1R Pvd(-) (pvd-inaZ) was not altered in the presence of a mutant of E . cloacae deficient in both enterobactin and aerobactin production . Therefore, the iron status of P . putida was altered by siderophores produced by an unrelated bacterium coinhabiting the rhizosphere . Finally, we demonstrated that INA expressed by N1R containing pvd-inaZ in the rhizosphere differed between plants grown in sterilized versus nonsterilized field soil . The results of this study demonstrate that (i) P . putida expresses genes for pyoverdine production and uptake in the rhizosphere, but the level of gene expression is influenced by other bacteria that coexist with P . putida in this habitat, and (ii) diverse groups of microorganisms can alter the availability of chemical resources in microbial habitats on root surfaces.

J Appl Microbiol, 1999 Oct, 87(4), 595 - 601
Microbiological characteristics of anevato: a traditional greek cheese
Hatzikamari M, Litopoulou-Tzanetaki E, Tzanetakis N.
Nine batches of Anevato, raw goat milk cheese, were examined throughout a 60 day storage time at three different periods within the lactation season of the goat . High mean log counts per gram of cheese for aerobic bacteria (7.92-9.56), lactic acid bacteria (7 . 78-9.32), Gram-negative organisms 5.64-9.67), psychrotrophs (7.90-11 . 79) and proteolytic bacteria (7.57-9.36) were found . Enterobacteriaceae, coliforms and yeasts were considerably lower . Enterobacteriaceae and coliforms in the curd of cheese made in May were lower by approximately 3.0 log10 cfu g-1 than counts in curd made in January, and were lower by about 2.5 log10 cfu g-1 than those in cheese made in March . This coincided with lower pH and higher counts of lactic acid bacteria in cheese made in March and May . Yeast populations were affected by the season and were higher in May than March and/or January . Lactococci dominated in the cheese until 15 days, but lactobacilli became predominant after 30 days . Lactococcus lactis was the most abundant species of lactic acid bacteria found in Anevato cheese . Results suggest the need for improving milk quality and/or using heat-treated milk to produce Anevato cheese; the use of L . lactis as a starter would possibly eliminate or suppress the growth of undesirable organisms.

Antimicrob Agents Chemother, 1999 Dec, 43(12), 2996 - 7
In vitro activities of SCH27899 alone and in combination with 17 other antimicrobial agents; Fuchs PC et al.; SCH27899, an everninomicin antibiotic, was tested for its in vitro activity against 718 bacterial isolates representing 27 species . The Enterobacteriaceae and nonenteric gram-negative bacilli were resistant to > or = 8.0 microg/ml, but all others were inhibited by < or = 1.0 microg/ml . When tested in combination with 17 other antimicrobial agents against 110 strains, SCH27899 demonstrated no significant antagonism or synergy . Consequently, combination therapy is not contraindicated.

Microbios, 1999, 100(395), 19 - 25
Bacterial degradation of hydrocarbons as evidenced by respirometric analysis; Saadoun I et al.; The microbial biodegradability of mineral oil and other hydrocarbons, namely hexane, decane and tetradecane was determined using the Warburg constant volume respirometer . Results of oxygen uptake indicated that hexane and tetradecane were more degradable than mineral oil and decane . Rhodococcus erythropolis and Erwinia cancerogena showed the highest (0.866) and lowest (0.115) oxygen quotient (Qo2) values, respectively, when exposed to mineral oil . Staphylococcus warneri and Enterobacter cloacae showed the highest (2.895) and (2.816) Qo2 values, respectively, when exposed to hexane; whereas E . cloacae and E . cancerogena showed the lowest Qo2 values (1.289 and 1.824), respectively . Both R . erythropolis and E . cloacae had the highest Qo2 values (2.859 and 2.289), respectively, when exposed to tetradecane . More oxygen was consumed by R . erythropolis than the other bacterial cultures when exposed to all hydrocarbons . In contrast, less oxygen was taken by E . cancerogena than the other bacterial cultures when exposed to all hydrocarbons, except for hexane.

Biochem Biophys Res Commun, 1999 Dec 9, 266(1), 248 - 51
In vivo modification of porin activity conferring antibiotic resistance to Enterobacter aerogenes; Chevalier J et al.; Cephalosporins are widely used in chemotherapy of bacterial infections and resistance mechanisms seriously impair their antibacterial activity . Several resistant strains of Enterobacter aerogenes, a frequently isolated nosocomial pathogen, were analyzed . One isolate exhibited a strong modification of the porin antigenic pattern, especially with an immunological probe directed against an epitope located inside the pore lumen . A strong decrease of cefepime uptake was evidenced for this isolate, similarly to ones observed for porin-deficient strains: these kinetics show a serious alteration of the channel properties which may support cephalosporin resistance . This is the first E . aerogenes isolate using such adaptive response which defines an original enterobacterial answer to cephalosporin .

Infect Control Hosp Epidemiol, 1999 Nov, 20(11), 746 - 51
An outbreak of gram-negative bacteremia in hemodialysis patients traced to hemodialysis machine waste drain ports; Wang SA et al.; OBJECTIVE: To investigate an outbreak of gram-negative bacteremias at a hemodialysis center (December 1, 1996-January 31, 1997) . DESIGN: Retrospective cohort study . Reviewed infection control practices and maintenance and disinfection procedures for the water system and dialysis machines . Performed cultures of the water and dialysis machines, including the waste-handling option (WHO), a drain port designed to dispose of saline used to flush the dialyzer before patient use . Compared isolates by pulsed-field gel electrophoresis . SETTING: A hemodialysis center in Maryland . RESULTS: 94 patients received dialysis on 27 machines; 10 (11%) of the patients had gram-negative bacteremias . Pathogens causing these infections were Enterobacter cloacae (n = 6), Pseudomonas aeruginosa (n = 4), and Escherichia coli (n = 2); two patients had polymicrobial bacteremia . Factors associated with development of gram-negative bacteremias were receiving dialysis via a central venous catheter (CVC) rather than via an arterio-venous shunt (all 10 infected patients had CVCs compared to 31 of 84 uninfected patients, relative risk {RR} undefined; P<.001) or dialysis on any of three particular dialysis machines (7 of 10 infected patients were exposed to the three machines compared to 20 of 84 uninfected patients, RR = 5.8; P = .005) . E cloacae, P aeruginosa, or both organisms were grown from cultures obtained from several dialysis machines . WHO valves, which prevent backflow from the drain to dialysis bloodlines, were faulty in 8 (31%) of 26 machines, including 2 of 3 machines epidemiologically linked to case-patients . Pulsed-field gel electrophoresis patterns of available dialysis machine and patient E cloacae isolates were identical . CONCLUSIONS: Our study suggests that WHO ports with incompetent valves and resultant backflow were a source of cross-contamination of dialysis bloodlines and patients' CVCs . Replacement of faulty WHO valves and enhanced disinfection of dialysis machines terminated the outbreak.

Diagn Microbiol Infect Dis, 1999 Oct, 35(2), 121 - 6
In-vitro activity of cefepime and other broad-spectrum antimicrobials against several groups of gram-negative bacilli and Staphylococcus aureus; Tallis E et al.; The in vitro activity of cefepime was compared with that of amikacin, ceftazidime, imipenem, ciprofloxacin, and piperacillin-tazobactam by using the E-test against five groups of carefully selected organisms: Klebsiella pneumoniae (68 isololates), Pseudomonas aeruginosa (62), methicillin-susceptible Staphylococcus aureus (MSSA) (60), and two groups of Enterobacteriaceae (60 and 62 isolates, respectively) . The bacteria were subdivided according to whether the infection was nosocomial or community-acquired, applying accepted and predefined criteria . These isolates were obtained from patients admitted to our medical center throughout 1998 . We retrospectively compared antimicrobial susceptibilities of the study sample with those of the +/- 3000 bacterial strains isolated from blood stream infections since 1990: the study sample appeared to represent adequately the clinical databank . Presence of extended-spectrum beta-lactamase (ESBL) was determined in all groups of Enterobacteriaceae with the ESBL screening E-test strip . Of the 252 Gram-negative bacilli tested, 242 (96%) were susceptible to cefepime, whereas only 168 (67%) were susceptible to ceftazidime, 211 (84%) to amikacin, and 220 (87%) to piperacillin-tazobactam (p < 0.001) . Imipenem was slightly superior to cefepime with only seven isolates resistant (3%), six of which were P . aeruginosa . Cefepime was more active against Enterobacteriaceae than ceftazidime (93% vs . 72%, p < 0.001) . This superiority was most evident against nosocomial strains of K . pneumoniae, against which cefepime was > three times more active than ceftazidime . The high level of resistance seen in nosocomial isolates of K . pneumoniae is consistent with high rates of ESBL production (69%, compared with 15-26% in other Enterobacteriaceae) . The MIC90 of cefepime to methicillin-sensitive S . aureus was 1.5 micrograms/mL, whereas that of ceftazidime was 4 micrograms/mL; the susceptibility rate of both was 100% . In conclusion, cefepime possesses in vitro potencies against MSSA and current clinical strains of Gram-negative bacilli, many of which harbor resistance to other antimicrobial agents . Hence, it seems very suitable for empiric coverage of serious nosocomial infections.

Lijec Vjesn, 1999 Jul-Aug, 121(7-8), 249 - 57
{Development of beta-lactam antibiotic resistance in gram-negative bacteria and the impact of resistance on therapy}; Bedenic B; Bacterial resistance to antibiotic is the inevitable consequence of the utilization of antimicrobial agents all over the world, particularly in developed countries . It is particularly evident with beta-lactam agents because they are among most frequently prescribed drugs . The resistance is mainly attributable to production of various types of beta-lactamases but other mechanisms like alterations in PBP molecules or in outer membrane proteins can play a significant role . Increased resistance can be seen among fastidious gram-negative bacteria like Haemophilus influenzae or Moraxella catarrhalis . The percentage of M . catarrhalis isolates producing beta-lactamases has increased to over 90% . Among Enterobacteriaceae E . coli and Klebsiella pneumoniae pose a very serious problem because of the production of extended-spectrum beta-lactamases which confer resistance to third generation cephalosporins . The percentage of ampicillin resistant E . coli among hospital isolates has rosen to 78% in U.S.A . nowadays . Recently, the emergence of E . coli strain resistant to combination of amoxycillin and clavulanate, due to hyperproduction of TEM-1 beta-lactamase, was observed . Inducible beta-lactamases mediate beta-lactam resistance in Pseudomonas aeruginosa which often develops during therapy of P . aeruginosa infections . Imipenem resistance is increasingly prevalent among P . aeruginosa isolates nowadays, but can be detected in K . pneumoniae due to the production of novel beta-lactamases and changes in outer membrane proteins.

J Bacteriol, 1999 Dec, 181(23), 7192 - 8
Interference with murein turnover has no effect on growth but reduces beta-lactamase induction in Escherichia coli; Kraft AR et al.; Physiological studies of a mutant of Escherichia coli lacking the three lytic transglycosylases Slt70, MltA, and MltB revealed that interference with murein turnover can prevent AmpC beta-lactamase induction . The triple mutant, although growing normally, shows a dramatically reduced rate of murein turnover . Despite the reduction in the formation of low-molecular-weight murein turnover products, neither the rate of murein synthesis nor the amount of murein per cell was increased . This might be explained by assuming that during growth in the absence of the major lytic transglycosylases native murein strands are excised by the action of endopeptidases and directly reused without further breakdown to muropeptides . The reduced rate of murein turnover could be correlated with lowered cefoxitin-induced expression of beta-lactamase, present on a plasmid carrying the ampC and ampR genes from Enterobacter cloacae . Overproduction of MltB stimulated beta-lactamase induction, whereas specific inhibition of Slt70 by bulgecin repressed ampC expression . Thus, specific inhibitors of lytic transglycosylases can increase the potency of penicillins and cephalosporins against bacteria inducing AmpC-like beta-lactamases.

J Food Prot, 1999 Nov, 62(11), 1341 - 5
Automated rapid screening of foods for the presence of salmonellae; Peng H et al.; We previously reported an accelerated method to detect salmonellae in foods . It consisted of a preenrichment step (6 h) followed by immunomagnetic separation (IMS) and automated detection, based on positive biochemical characteristics, during overnight incubation . We describe here a simplified procedure with a detection limit of 2 CFU/25 g of food, a procedure that does not require the IMS step . Liquid eggs, milk, ice cream, or poultry were inoculated with Salmonella or non-Salmonella Enterobacteriaceae organisms (2 to 100 CFU/25 g) . Following preenrichment for 6 h at 35 degrees C, samples (3 ml) were added to selective liquid media (6 ml) . Automated light transmittance was recorded during incubation at 42 degrees C in the BioSys instrument . Salmonella-positive samples were identified by a sharp drop in transmittance (caused by black discoloration of the media) within 18 h of incubation following the formation of hydrogen sulfide and its reaction with iron ions . Detection of 2 to 10 CFU/25 g of the tested foods was completed in 24 h . A total of 24 Salmonella spp., including heat-injured cells, and 37 non-Salmonella Enterobacteriaceae were tested using the procedure.

J Food Prot, 1999 Nov, 62(11), 1333 - 5
Occurrence of Escherichia coli O157:H7 in hamburgers produced in Brazil; Silveira NF et al.; The occurrence of Escherichia coli O157:H7 was evaluated in 886 samples of hamburgers produced by eight manufacturers in the south and southeast of Brazil from January to September of 1997 . The pathogen was not detected in any of the samples analyzed, although 17 (1.9%) showed the presence of E . coli strains, which presented agglutination with O157 antiserum . These strains were not confirmed, since a subsequent identification indicated that they were fermentation positive for sorbitol, incapable of agglutination with the antisera of other commercial brands, and nonproducers of verocytotoxins . A high rate of false-presumptive-positive tests was observed with strains of enterobacteria when isolated by the culture method and when using a commercially purchased enzymatic immunoassay . This high rate of false presumptive positives was likely because the initial screening for sorbitol-negative strains was carried out using phenol red sorbitol 4-methylumbelliferyl-beta-D-glucuronide agar, which was shown to be inadequate for this purpose.

J Food Prot, 1999 Nov, 62(11), 1270 - 7
Bacterial microflora of wild brown trout (Salmo trutta), wild pike (Esox lucius), and aquacultured rainbow trout (Oncorhynchus mykiss); Gonzalez CJ et al.; Initial numbers of bacteria associated with wild (brown trout and pike) and cultured (rainbow trout) freshwater fish as well as with the water in which they were caught were determined . Subsequently, a total of 979 randomly selected isolates were characterized and identified to the genus level . For all counts performed (aerobes, psychrotrophs, anaerobes, Enterobacteriaceae, and enterococci), no significant differences were observed in water samples, the highest level corresponding to psychrotrophs in pike environments (4.23 X 10(3) CFU/ml) . Overall, the skin and intestinal content of brown trout were the most contaminated, while rainbow trout specimens (gills and gut) yielded the lowest numbers . For all bacterial groups, pike gills had the highest numbers . Counts for all of the sampling sites compare well with findings in other temperate geographical environments . Biological characteristics (feeding and skin properties) and the use of antimicrobials in aquaculture might have influenced these results . Motile and nonmotile aerobic gram-negative bacteria together with Enterobacteriaceae accounted for 50 to 70% of the psychrotrophs isolated from water . Micrococcaceae, lactic acid bacteria, Bacillus, and coryneforms were also found . The groups represented in psychrotrophic isolates from the outer surfaces do not reflected those detected in water, so it was common that those organisms recovered in significant numbers from fish were not detected in surrounding habitat of the fish . Motile aeromonads and Carnobacterium were the dominant psychrotrophs in the guts of pike and brown trout, respectively . The intestinal content of reared fish gave a high incidence of Bacillus and coryneforms, while Enterobacteriaceae was absent . Again, rearing practices could have influenced this finding . Listeria monocytogenes was not detected in any of the examined samples . Two strains of Salmonella, which belonged to the same serovar and lysotype, were recovered from pond-water samples taken from one facility on different sampling days . From the gut of a pike specimen and from the pike's environment, two Plesiomonas shigelloides strains of different serovars were recovered . These latter four strains were resistant to a considerable number of antimicrobial compounds (multiple antibiotic resistance indices > 0.2).

Cir Pediatr, 1999 Apr, 12(2), 56 - 60
{Bacterial translocation in intestinal transplant}; Jimenez Almonacid P et al.; OBJECTIVE: To analyse the influence of ceftriaxone on bacterial translocation and survival after small bowel transplantation in an experimental model with large animals . DESIGN: We performed 21 small bowel transplantation in pigs . Group 1 (n = 5): small bowel transplantation (SBT) . Group 2 (n = 5): SBT and immunosuppression with cyclosporine, azathioprine and prednisolone . Group 3 (n = 5): SBT and ceftriaxone . Group 4 (n = 6): SBT, ceftriaxone and immunosuppression . SUBJECTS: Minipig of 25-45 Kg body weight . MEASURES: Blood, spleen, liver, and mesenteric lymph nodes for bacterial culture and biopsy of ileum on postoperative days POD 0.3 and 7 . RESULTS: Cultures were positive for bacteria in 22% (10/41) before perfusion, and 43% (28/67) post-reperfusion . Groups 1 and 2: cultures were positive for bacteria in 93% (28/30) on POD 3 degrees, and in 100% (30/30) on POD 7 degrees . Cultures were positive for enterobacteria in 80% (24/30) on POD 3 degrees . Groups 3 and 4: cultures were positive for bacteria in 79.5% (33/41) on POD 3 degrees and in 100% (31/31) on POD 7 degrees . Cultures were positive for enterobacteria in 36.5% (15/41) on POD 3 degrees . Early mortality (before POD 7 degrees), not related with technical complications was 50% (5/10) in groups 1 and 2 and 0% (0/11) in groups 3 and 4 . There were no differences with the use of immunosuppression . CONCLUSIONS: Ceftriaxone could decrease bacterial translocation (especially enterobacteria), and early mortality post-small bowel transplantation in pigs.

Appl Microbiol Biotechnol, 1999 Oct, 52(4), 489 - 94
Fluorescence monitoring during cultivation of Enterobacter aerogenes at different oxygen levels; Mukherjee J et al.; On-line monitoring of NAD(P)H fluorescence and 2D fluorescence spectroscopy was performed with Enterobacter aerogenes, a bacterium sensitive to oxygen availability . The organism was grown in a reactor under low and high dissolved oxygen concentrations and circulated through a bypass attached to the reactor . Under low dissolved oxygen concentration in the reactor, NAD(P)H fluorescence in the reactor and the bypass showed a deviation, but not when the dissolved oxygen level in the reactor was high . The pattern of growth curves was identical under low and high oxygen levels . This indicates a difference in the metabolic activity of E . aerogenes in response to oxygen . The difference spectrum of the 2D fluorescence shows that growing E . aerogenes under high dissolved oxygen levels increases the NAD(P)H content of the cells.

Rhinology, 1999 Sep, 37(3), 113 - 6
Prospective randomized investigation for evaluation of postoperative changes in the microbial climate of paranasal mucosa by the use of different dissoluting techniques during postoperative care; Maune S et al.; Endonasal dissolution by the use of NaCl-solution is a common postoperative treatment of the nasal mucosa after endonasal surgery . These procedure involve for example endonasal shower and sterilized solutions . The contamination of nasal shower in case of unprofessional cleaning after treatment was an argument against this technique in earlier discussions . The danger of such an infection should be avoided by the use of sterilized solution . Therefore the dependence of nasal microbial climate on different nasal dissoluting techniques was investigated by the use of such named endonasal shower (Siemens und Co, Bad Ems, Germany) in comparison with sterilized solution (Rhinomer, Zyma SA, Nyon, France) . Microbial cultures were investigated of 80 patients after endonasal surgery (53 m, 27 f; 31 +/- 21 age) . Surgery was done for the treatment of chronic polypous sinusitis . Pre-, intra- and postoperative samples were taken in 640 cases to proceed microbial cultures . Material was transferred with the use of a Port-A-Cul-transport medium and preparation of the microbial cultures was done during the first four hours . As a result 895 bacterial clones were cultivated . These consisted of 87% aerob and 13% anaerob bacteria . Staphylococcus aureus (39%) and members of the family of Enterobactericae (30%) were the most common microbes . There was neither an evidence for postoperative microbes on the nasal mucosa nor a correlation between the dissoluting technique and the postoperative outcome . The use of sterilized solutions for the postoperative care of endonasal mucosa does not cause an additional worthful effect on neither the postoperative microbial climate nor the outcome in comparison to endonasal shower.

Chemotherapy, 1999 Nov-Dec, 45(6), 405 - 10
In vitro antibacterial activity of men 10700, a new penem antibiotic; Varotto F et al.; We report here the antibacterial activity of the new penem antibiotic Men 10700 against a total of 740 gram-positive and gram-negative clinical isolates, in comparison to imipenem, meropenem, cefotaxime, ceftriaxone, ciprofloxacin and gentamicin . Men 10700 has shown a wide spectrum of antibacterial activity, with a potent activity both against gram-positive species (with the exception of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis) as indicated by minimal inhibitory concentration (MIC(90)) values < or =0.5 mg/l, and gram-negative species, with MIC(90) values generally < or =2 mg/l . Men 10700 was the most potent antibiotic against methicillin-susceptible S . aureus and S . epidermidis, while the overall spectrum of activity resembled that of imipenem; meropenem was more active against most gram-negative species . In comparison with third-generation cephalosporins, Men 10700 demonstrated superior activity against methicillin-susceptible S . aureus and S . epidermidis and some gram-negative species such as Morganella morganii, Serratia spp . and Enterobacter cloacae; moreover, in contrast to third-generation cephalosporins, Men 10700 showed moderate activity against Enterococcus spp . The activity of Men 10700 against penicillin-resistant Streptococcus pneumoniae (10 strains) and some gram-negative strains selected for their resistance to cefotaxime (20 strains) was particularly interesting . Copyright

Microb Drug Resist, 1999 Fall, 5(3), 189 - 93
Extended-spectrum beta-lactamases in clinical isolates of enterobacteria in Mexico; Silva J et al.; Resistance to extended-spectrum cephalosporins within members of the family Enterobacteriaceae occurs virtually world-wide . Nevertheless, nothing was known about this problem among isolates from Mexico . To address this issue, we studied oximino-cephalosporin resistant isolates of Klebsiella pneumoniae (13), Escherichia coli (7), and Enterobacter cloacae (23) recovered from patients in Mexico City hospitals during 1990 to 1992 . In the presence of clavulanic acid, these strains increased susceptibility to cefotaxime and ceftazidime (MIC90 64 and >256 microg/ml, respectively) . The ability of these isolates to transfer resistance to both antibiotics by conjugation was most successfully demonstrated by K . pneumoniae . In all the clinical isolates tested, the largest plasmid coded for the extended-spectrum beta-lactamases (ESBL) . Characteristics of pI, by isoelectric focusing (IEF)/bioassay and DNA hybridization with specific probes of TEM and SHV, indicated that in most of the clinical isolates and all transconjugates, the most frequent beta-lactamase coded were SHV-derived (20 strains as 41% of isolates) and a plasmid-encoded beta-lactamase (12 strains as 25% of isolates) (with a pI of >8.2), which is not related to TEM/SHV . Apparently, isolates from Mexico show characteristics similar to isolates from other geographic areas . The type of beta-lactamases coded in these resistant isolates is documented for the first time in Mexico.

Eur J Biochem, 1999 Dec, 266(2), 420 - 30
Functional consequences of mutations in the conserved 'signature sequence' of the ATP-binding-cassette protein MalK; Schmees G et al.; The binding-protein-dependent maltose-transport system of enterobacteria, a member of the ATP-binding-cassette (ABC) transporter superfamily, is composed of two integral membrane proteins, MalF and MalG, and two copies of an ATPase subunit, MalK, which hydrolyze ATP, thus energizing the translocation process . Isolated MalK displays spontaneous ATPase activity, whereas in the assembled MalFGK2 complex, reconstituted in liposomes, ATP hydrolysis requires stimulation by the substrate-loaded extracellular maltose-binding protein, MalE . The ATPase domains of ABC transporters, including MalK, share a unique sequence motif ('LSGGQ', 'signature sequence' or 'linker peptide') with as yet unknown function . To elucidate its role in the transport process, we investigated the consequences of mutations affecting two highly conserved residues (G137, Q140) in the MalK-ATPase of Salmonella typhimurium, by biochemical means . Residues corresponding to Q140 in other ABC proteins have not yet been studied . All mutant alleles (G137--> A, V, T; Q140--> L, K, N) fail to restore a functional transport complex in vivo . In addition, the mutations increase the repressing activity of MalK on other maltose-regulated genes when compared with wild-type MalK . Purified variants of G137 have lost the ability to hydrolyze ATP but still display nucleotide-binding activity, albeit with reduced affinity . Binding of MgATP results in similar protection against trypsin, as observed with wild-type, indicating no major change in protein structure . In contrast, the variants of Q140 differ in their properties, depending on the chemical nature of the replacement residue . MalKQ140L fails to hydrolyze ATP and exhibits a strong intrinsic resistance to trypsin in the absence of MgATP, suggesting a drastically altered conformation . In contrast, the purified mutant proteins Q140K and Q140N display ATPase activities and MgATP-induced changes in the tryptic cleavage pattern similar to those of wild-type . However, mutant transport complexes containing the Q140K or Q140N variants, when studied in proteoliposomes, are severely impaired in MalE-maltose-stimulated ATPase activity . These results are discussed with respect to the crystal structure of the homologous HisP protein {Hung, L.-W., Wang, I.X., Nikaido, K., Liu, P.-Q., Ames, G.F.-L . & Kim, S.-H . (1998) Nature (London) 396, 703-707} and are interpreted in favor of a role of the signature sequence in activating the hydrolyzing activity of MalK upon substrate-initiated conformational changes in MalF/MalG.

J Infect Dis, 1999 Dec, 180(6), 1809 - 18
Emergence of trimethoprim-sulfamethoxazole resistance in the AIDS era; Martin JN et al.; Trimethoprim-sulfamethoxazole (TMP-SMX) is widely used for Pneumocystis carinii pneumonia prophylaxis in human immunodeficiency virus (HIV)-infected patients, but little is known about the effects of this practice on the emergence of TMP-SMX-resistant bacteria . A serial cross-sectional study of resistance to TMP-SMX among all clinical isolates of Staphylococcus aureus and 7 genera of Enterobacteriaceae was performed at San Francisco General Hospital . Resistance among all isolates was <5.5% from 1979 to 1986 but then markedly increased, reaching 20.4% in 1995 . This was most prominent in HIV-infected patients: resistance increased from 6.3% in 1988 to 53% in 1995 . The largest increases in resistance were in Escherichia coli (24% in 1988 to 74% in 1995) and S . aureus (0% to 48%) obtained from HIV-infected patients . A rapid increase in the use of prophylactic TMP-SMX in HIV disease was also observed during this time in San Francisco and is likely responsible for the increase in TMP-SMX resistance.

Schweiz Med Wochenschr, 1999 Oct 23, 129(42), 1521 - 8
Nosocomial infections in Swiss university hospitals: a multi-centre survey and review of the published experience . Swiss-Noso Network; Harbarth S et al.; A one-week period-prevalence survey, aimed at assessing the scale of nosocomial infections, was conducted in May 1996 in medical, surgical, and intensive care wards of 4 Swiss university hospitals . Standard definitions by the Centres for Disease Control and Prevention were used except that asymptomatic bacteriuria was not classified as a nosocomial infection . A total of 176 nosocomial infections were found among 156 of the 1349 surveyed patients (prevalence 11.6%; interhospital range 9.8-13.5%) . Surgical site infections were most prevalent (30% of all nosocomial infections), followed by urinary tract (22%), lower respiratory tract (15%), and bloodstream infections (13%) . The most frequently isolated microorganisms were Enterobacteriaceae (n = 44; 28%), S . aureus (n = 20; 13%), Pseudomonas spp (n = 17; 11%), and Candida spp (n = 16; 10%) . One third of all episodes of nosocomial infections were not microbiologically documented . The overall prevalence of nosocomial infections in surgical patients (n = 562) was 16.2% compared to 8.6% for non-surgical patients (prevalence ratio, 1.9; 95% confidence interval {CI95}, 1.4-2.5) . In one centre, the in-hospital mortality of patients with nosocomial infections was 9.2% (10/109) compared to 3.9% (25/637) for patients without nosocomial infections (odds ratio, 2.47; CI95, 1.15-5.31) . Infection rates were similar to those reported by two Swiss pilot studies from the early 1980s . This study offers a reliable measure of the prevalence of nosocomial infections in selected wards at 4 Swiss university hospitals and confirms the importance of nosocomial infections as a heavy burden on health services at the end of this century.

J Clin Microbiol, 1999 Dec, 37(12), 4186 - 8
Identification of Hafnia alvei with the MicroScan WalkAway system; Rodriguez LA et al.; Hafnia alvei is a gram-negative facultatively anaerobic bacillus that belongs to the family Enterobacteriaceae . This organism is a causative agent of intestinal disorders and is found in different environments . H . alvei has received increased clinical attention as a cause of different infections in humans . This study was performed to compare the MicroScan WalkAway automated identification system in conjunction with the new MicroScan Combo Negative type 1S panels with conventional biochemical methods for identification of 21 H . alvei strains . The MicroScan WalkAway system was found capable of correctly identifying 20 of the 21 strains tested.

Mikrobiol Z, 1999 Jul-Aug, 61(4), 45 - 53
{The identification of freshly isolated strains, the causative agents of human candidiasis and the search for effective antifungal probiotics}; Polishchuk OI et al.; The species variety of yeasts of the genus Candida in children and patients with AIDS has been investigated . Composition of the studied species was found to be similar in newborns and in women with candidiasis . In order to create new probiotics with antifungal properties, the cluster analysis of antagonistic activity of some Bacillus strains against Enterobacteriaceae, Candida, normoflora and food-fermenting lactobacteria has been conducted . There were selected the combinations of some Bacillus strains, which effectively inhibited pathogenic and opportunistic microorganisms and at the same time had no effect on intestinal normoflora.

FEMS Microbiol Lett, 1999 Dec 1, 181(1), 17 - 23
Genetic rearrangements in the tyrB-uvrA region of the enterobacterial chromosome: a potential cause for different class B acid phosphatase regulation in Salmonella enterica and Escherichia coli; Thaller MC et al.; Unlike in Escherichia coli, in Salmonella enterica production of class B acid phosphatase (AphA) was detectable also in cells growing in the presence of glucose . Characterization of the aphA locus from a S . enterica ser . typhi strain showed that the aphA determinant is very similar to the E . coli homolog, and that its chromosomal location between the highly conserved tyrB and uvrA genes is retained . However, the aphA flanking regions were found to be markedly different in the two species, either between tyrB and aphA or between aphA and uvrA . The differences in the aphA 5'-flanking region, which in S . enterica is considerably shorter than in E . coli (183 vs . 1121 bp) and includes potential promoter sequences not present in E . coli, could be responsible for the different regulation of class B acid phosphatase observed in the two species.

Bioconjug Chem, 1999 Nov-Dec, 10(6), 1084 - 9
Comparison of recombinant and synthetically formed monoclonal antibody-beta-lactamase conjugates for anticancer prodrug activation; Kerr DE et al.; Conjugates of the L49 monoclonal antibody (binds to the p97 antigen on melanomas and carcinomas) were formed by attaching Enterobacter cloacae beta-lactamase (bL) to the L49-Fab' fragment using a heterobifunctional cross-linking reagent or by linking the enzyme to L49-sFv using DNA recombinant technology . The conjugates thus formed, L49-Fab'-bL and L49-sFv-bL, were designed to activate cephalosporin containing anticancer prodrugs at the surfaces of antigen positive tumor cells . Results from in vitro experiments using two lung carcinoma cell lines demonstrated that the conjugates were equally active in effecting the release of phenylenediamine mustard from the cephalosporin nitrogen mustard prodrug CCM . While treatment with either of the conjugates combined with the maximum tolerated doses of CCM led to cures of established SN12P renal cell carcinoma tumors in nude mice, only the L49-sFv-bL conjugate maintained its ability to do so at 1/4 the maximum tolerated dose of CCM . L49-sFv-bL was also superior to L49-Fab'-bL in the 1934J renal cell carcinoma tumor model and was shown to be quite active in two in vivo models of human lung carcinoma . These results demonstrate that the recombinant fusion protein leads to more pronounced therapeutic windows than the chemical conjugate and is active in an array of human tumor models.

Int J Food Microbiol, 1999 Oct 1, 51(1), 67 - 79
Modelling the interactions between Lactobacillus curvatus and Enterobacter cloacae . II . Mixed cultures and shelf life predictions; Malakar PK et al.; The modelling approach presented in this study can be used to predict when interactions between microorganisms in homogenous systems occur . It was tested for the interaction between Lactobacillus curvatus and Enterobacter cloacae . In this binary system, L . curvatus produces lactic acid which decreases the pH in the system . The pH decrease was found to be the main limiting factor of growth of both E . cloacae and L . curvatus . This resulted in E . cloacae reaching its final concentration earlier when compared to its growth in pure culture . The models consisted of a set of first order ordinary differential equations describing the growth, consumption and production rates of both microorganisms . The parameters for these equations were obtained from pure culture studies and from literature . These equations were solved using a combination of analytical and numerical methods . The prediction of growth in mixed culture using parameters from pure culture experiments and literature were close to the experimental data . Both model predictions and experimental validation indicated that interaction occurs when the concentration of L . curvatus reaches 10(8) cfu/ml . At that moment in time, the pH had decreased to inhibiting levels . These concentrations of microorganisms (10(8) cfu/ml) do occur in fermented products where interactions obviously are important . In nonfermented foods however, this level of microorganisms indicate that spoilage has occurred or is about to start . Microbial interactions can therefore be neglected when predicting shelf life or safety of food products in most cases.

Int J Food Microbiol, 1999 Oct 1, 51(1), 53 - 65
Modelling the interactions between Lactobacillus curvatus and Enterobacter cloacae . I . Individual growth kinetics; Martens DE et al.; Mixed cultures of Lactobacillus curvatus and Enterobacter cloacae were chosen as a model system to quantitatively study microbial interactions involved in food spoilage and food preservation . In this paper models were developed to predict the individual behaviour of L . curvatus and E . cloacae in pure suspension cultures as a function of the glucose and lactate concentration and the pH . In a second paper these models will be used to predict the moment of interaction in mixed suspension cultures and the cell concentrations at this moment . The effect of pH on the maximum specific growth rate could be described by a parabolic equation for L . curvatus and E . cloacae . E . cloacae is clearly more sensitive to a pH decrease than L . curvatus, as may be concluded from the theoretical minimum pH for growth of 5.6 for E . cloacae and 4.3 for L . curvatus . For both organisms no effect of glucose on the maximum specific growth rate could be detected and Monod kinetics with a low Monod constant was assumed . For L . curvatus the effect of lactate on the maximum specific growth rate at different initial pH values could be described by a linear relationship . For E . cloacae a slight effect of lactate on the maximum specific growth rate could only be detected at pH 7 . However, this effect was negligible compared to the effect of the pH . For both organisms the lag time was modelled by the inverse of the specific growth rate . It can be concluded that, with regard to interactions between L . curvatus and E . cloacae, the pH is likely to be the most important factor in the case where L . curvatus is the dominant organism . Substrate limitation is likely to become important in the case where E . cloacae is the dominant organism or for media with a high buffer capacity.

J Bacteriol, 1999 Nov, 181(22), 6929 - 36
IS1397 is active for transposition into the chromosome of Escherichia coli K-12 and inserts specifically into palindromic units of bacterial interspersed mosaic elements; Clement JM et al.; We demonstrate that IS1397, a putative mobile genetic element discovered in natural isolates of Escherichia coli, is active for transposition into the chromosome of E . coli K-12 and inserts specifically into palindromic units, also called repetitive extragenic palindromes, the basic element of bacterial interspersed mosaic elements (BIMEs), which are found in intergenic regions of enterobacteria closely related to E . coli and Salmonella . We could not detect transposition onto a plasmid carrying BIMEs . This unprecedented specificity of insertion into a well-characterized chromosomal intergenic repeated element and its evolutionary implications are discussed.

Int J Syst Bacteriol, 1999 Oct, 49 Pt 4, 1531 - 8
Identification of Enterobacteriaceae by partial sequencing of the gene encoding translation initiation factor 2; Hedegaard J et al.; Nucleotide sequence analysis is increasingly being used to identify bacteria . In this work, a PCR assay based on degenerate primers was used to obtain the partial sequence of infB, the gene encoding translation initiation factor 2 (IF2), in 39 clinical isolates of different Enterobacteriaceae . The partial sequence encodes the GTP-binding domain of IF2 . Together with sequences from the literature, a total of 15 species, each represented by one to seven strains, was investigated . Phylogenetic analysis yielded an evolutionary tree which had a topology similar to a tree constructed using available 16S rRNA sequences . It is concluded that the inter-species variation of the infB gene fragment is sufficient for its use in the characterization of strains that have aberrant phenotypic reactions.

Am Surg, 1999 Nov, 65(11), 1031 - 4
Minimal debridement in the treatment of Fournier's gangrene; Frezza EE et al.; Scrotal and perineal gangrene of the male genitalia was first described by Fournier in 1883 . Treatment of the disease remains surgical despite the availability of modern antibiotics . Many authors advocate a wide debridement of all tissue superficial to the involved fascial layers . We have reviewed our experience of using wide and minimal debridement as the surgical technique of choice . In our retrospective study, nine patients were diagnosed and treated over a 2-year period for Fournier's gangrene . The mean age was 65+/-28 years . Two patients were admitted from chronic care facilities, four were diabetic, and two had taken oral steroids . Five of the nine patients were treated with the technique of minimal tissue debridement . In brief, the scrotum was bivalved along the median raphe, each scrotal sac was drained, and the testicles were exteriorized . Orchiectomy was performed if the testicles were grossly necrotic . Penrose drains were inserted from each scrotal sac to the counterincision at the level of the internal rings . All of the tissue involved was irrigated with betadine and peroxide, after debridement of the necrotic tissue . Broad-spectrum antibiotics along with daily packing were continued for 4 to 6 weeks; at the end of that time the testicles were returned to the scrotum and the skin was loosely reapproximated . Three of the nine patients were treated with wide debridement of all the soft tissue including the fascia . One of the patients displayed gangrene of the entire abdominal wall; he was not a surgical candidate and died 3 days later . The four patients treated with minimal debridement all obtained successful treatment of their fasciitis . However, one died of complications related to a duodenal ulcer . The mean hospital stay was 45+/-10 days . Two of the three patients treated with wide debridement required plastic reconstruction using a skin-muscle flap of the perineum . The remaining patient treated with wide debridement died of complications related to metastatic renal carcinoma . The mean hospital stay of this group was 62+/-12 days . The specific flora included: Bacteroidis fragilis in 87 per cent, Peptostreptococcus and Streptococcus in 75 per cent, Clostridia group, Escherichia coli, Enterobacter and Pseudomonas in 62 per cent, Klebsiella in 50 per cent, Staphylococcus in 37 per cent, and Proteus in 12 per cent of the patients . In the surgical management of Fournier's gangrene, wide drainage with minimal debridement resulted in similar morbidity and shorter hospital stay when compared with extensive debridement.

Appl Environ Microbiol, 1999 Nov, 65(11), 4898 - 907
Distribution of tetracycline resistance genes and transposons among phylloplane bacteria in Michigan apple orchards; Schnabel EL et al.; The extent and nature of tetracycline resistance in bacterial populations of two apple orchards with no or a limited history of oxytetracycline usage were assessed . Tetracycline-resistant (Tc(r)) bacteria were mostly gram negative and represented from 0 to 47% of the total bacterial population on blossoms and leaves (versus 26 to 84% for streptomycin-resistant bacteria) . A total of 87 isolates were screened for the presence of specific Tc(r) determinants . Tc(r) was determined to be due to the presence of Tet B in Pantoea agglomerans and other members of the family Enterobacteriacae and Tet A, Tet C, or Tet G in most Pseudomonas isolates . The cause of Tc(r) was not identified in 16% of the isolates studied . The Tc(r) genes were almost always found on large plasmids which also carried the streptomycin resistance transposon Tn5393 . Transposable elements with Tc(r) determinants were detected by entrapment following introduction into Escherichia coli . Tet B was found within Tn10 . Two of eighteen Tet B-containing isolates had an insertion sequence within Tn10; one had IS911 located within IS10-R and one had Tn1000 located upstream of Tet B . Tet A was found within a novel variant of Tn1721, named Tn1720, which lacks the left-end orfI of Tn1721 . Tet C was located within a 19-kb transposon, Tn1404, with transposition genes similar to those of Tn501, streptomycin (aadA2) and sulfonamide (sulI) resistance genes within an integron, Tet C flanked by direct repeats of IS26, and four open reading frames, one of which may encode a sulfate permease . Two variants of Tet G with 92% sequence identity were detected.

Biofizika, 1999 Jul-Aug, 44(4), 611 - 9
{Statistical analysis and prediction of bacterial sites for ribosomal binding}; Borovina TA et al.; An algorithm for recognition of prokaryotic ribosomal binding sites is suggested . The parameter library contains weight matrices for mapping of gene starts in various bacterial genomes . Comparison of the ribosome binding starts in different taxonomic groups demonstrates that the signals in Gram-positive bacteria are stronger than in Gram-negative bacteria, and in particular, Enterobacteria . The recognition matrices are available by e-mail misha@imb.imb.ac.ru.

Drug Des Discov, 1999 Aug, 16(2), 145 - 53
Analysis of affinities of penicillins for a class C beta-lactamase by molecular dynamics simulations; Tsuchida K et al.; We present a calculation for the binding free energy difference between two complexes of the class C beta-lactamase from Enterobacter cloacae with foramidocillin (FOPC) and with piperacillin (PIPC) . The calculation was carried out by means of the thermodynamic integration (TI) method implemented with molecular dynamics (MD) . By use of the available crystal structure of the class C beta-lactamase from E . cloacae, the structures of the beta-lactamase-FOPC (FOPC complex) and beta-lactamase-PIPC (PIPC complex) complexes were built by molecular modeling and equilibrated with MD simulations . FOPC were gradually converted into PIPC in both the solution and the enzyme system by means of MD/TI methods during the MD simulation . The structure of the PIPC complex as derived by the MD/TI simulation was similar to that of the PIPC complex obtained from molecular modeling . The calculated difference in the free energy of binding (deltadeltaGbind) was -2.2 kcal/mol . This compares well with the experimental value of -1.5 kcal/mol . The results indicate that the binding affinity of FOPC is lower than that of PIPC because of the greater difficulty of desolvation for FOPC upon binding to the enzyme . This calculation suggests that the desolvation of the ligand, as well as its interaction with the beta-lactamase, is important in understanding the relative affinity of the ligands with beta-lactamase.

Appl Microbiol Biotechnol, 1999 Sep, 52(3), 321 - 6
Production of 2,3-butanediol by newly isolated Enterobacter cloacae; Saha BC et al.; Enterobacter cloacae NRRL B-23289 was isolated from local decaying wood/corn soil samples while screening for microorganisms for conversion of L-arabinose to fuel ethanol . The major product of fermentation by the bacterium was meso-2,3-butanediol (2,3-BD) . In a typical fermentation, a BD yield of 0.4 g/g arabinose was obtained with a corresponding productivity of 0.63 g/l per hour at an initial arabinose concentration of 50 g/l . The effects of initial arabinose concentration, temperature, pH, agitation, various monosaccharides, and multiple sugar mixtures on 2,3-BD production were investigated . BD productivity, yield, and byproduct formation were influenced significantly within these parameters . The bacterium utilized sugars from acid plus enzyme saccharified corn fiber and produced BD (0.35 g/g available sugars) . It also produced BD from dilute acid pretreated corn fiber by simultaneous saccharification and fermentation (0.34 g/g theoretical sugars).

Appl Microbiol Biotechnol, 1999 Sep, 52(3), 289 - 97
Microbial production of 1,3-propanediol; Biebl H et al.; 1,3-Propanediol (1,3-PD) production by fermentation of glycerol was described in 1881 but little attention was paid to this microbial route for over a century . Glycerol conversion to 1,3-PD can be carried out by Clostridia as well as Enterobacteriaceae . The main intermediate of the oxidative pathway is pyruvate, the further utilization of which produces CO2, H2, acetate, butyrate, ethanol, butanol and 2,3-butanediol . In addition, lactate and succinate are generated . The yield of 1,3-PD per glycerol is determined by the availability of NADH2, which is mainly affected by the product distribution (of the oxidative pathway) and depends first of all on the microorganism used but also on the process conditions (type of fermentation, substrate excess, various inhibitions) . In the past decade, research to produce 1,3-PD microbially was considerably expanded as the diol can be used for various polycondensates . In particular, polyesters with useful properties can be manufactured . A prerequisite for making a "green" polyester is a most cost-effective production of 1,3-PD, which, in practical terms, can only be achieved by using an alternative substrate, such as glucose instead of glycerol . Therefore, great efforts are now being made to combine the pathway from glucose to glycerol successfully with the bacterial route from glycerol to 1,3-PD . Thus, 1,3-PD may become the first bulk chemical produced by a genetically engineered microorganism.

Infect Immun, 1999 Nov, 67(11), 5994 - 6001
A genomic island, termed high-pathogenicity island, is present in certain non-O157 Shiga toxin-producing Escherichia coli clonal lineages; Karch H et al.; Shiga toxin-producing Escherichia coli (STEC) strains cause a wide spectrum of diseases in humans . In this study, we tested 206 STEC strains isolated from patients for potential virulence genes including stx, eae, and enterohemorrhagic E . coli hly . In addition, all strains were examined for the presence of another genetic element, the high-pathogenicity island (HPI) . The HPI was first described in pathogenic Yersinia species and encodes the pesticin receptor FyuA and the siderophore yersiniabactin . The HPI was found in the genome of distinct clonal lineages of STEC, including all 31 eae-positive O26:H11/H(-) strains and 7 of 12 eae-negative O128:H2/H(-) strains . In total, the HPI was found in 56 (27.2%) of 206 STEC strains . However, it was absent from the genome of all 37 O157:H7/H(-), 14 O111:H(-), 13 O103:H2, and 13 O145:H(-) STEC isolates, all of which were positive for eae . Polypeptides encoded by the fyuA gene located on the HPI could be detected by using immunoblot analysis in most of the HPI-positive STEC strains, suggesting the presence of a functional yersiniabactin system . The HPI in STEC was located next to the tRNA gene asnT . In contrast to the HPI of other pathogenic enterobacteria, the HPI of O26 STEC strains shows a deletion at its left junction, leading to a truncated integrase gene int . We conclude from this study that the Yersinia HPI is disseminated among certain clonal subgroups of STEC strains . The hypothesis that the HPI in STEC contributes to the fitness of the strains in certain ecological niches rather than to their pathogenic potential is discussed.

Infect Immun, 1999 Nov, 67(11), 5587 - 96
Characterization of pic, a secreted protease of Shigella flexneri and enteroaggregative Escherichia coli; Henderson IR et al.; We have identified and characterized a secreted protein, designated Pic, which is encoded on the chromosomes of enteroaggregative Escherichia coli (EAEC) 042 and Shigella flexneri 2457T . The product of the pic gene is synthesized as a 146.5-kDa precursor molecule which is processed at the N and C termini during secretion, allowing the release of a mature protein (109.8 kDa) into the culture supernatant . The deduced amino acid sequence of Pic shows high homology to autotransporter proteins, particularly a subgroup termed the SPATEs (serine protease autotransporters of the Enterobacteriaceae) . Present in all members of this subgroup is a motif similar to the active sites of certain serine proteases . Pic catalyzes gelatin degradation, which can be abolished by disruption of the predicted proteolytic active site . Functional analysis of the Pic protein implicates this factor in mucinase activity, serum resistance, and hemagglutination . Our data suggest that Pic may be a multifunctional protein involved in enteric pathogenesis.

J Ocul Pharmacol Ther, 1999 Oct, 15(5), 439 - 45
Penetration and decay of meropenem into the human aqueous humor and vitreous; Schauersberger J et al.; The aim of this study was to determine the penetration of intravenously administered meropenem into the human aqueous humor and vitreous . Thirty patients about to undergo cataract surgery and fourteen patients about to undergo vitrectomy received a 2 g dose of meropenem before surgery . Specimens of aqueous humor or vitreous and blood were obtained intraoperatively and analyzed by high performance liquid chromatography (HPLC) . The study was designed as a non-randomized prospective trial . Thirty min to 12 hr after administration, mean aqueous humor levels of 13.4 and 1.1 mg/l and vitreous levels between 8.94 and 1.08 mg/l were found, respectively . The peak concentrations are distinctly above the in vitro measured minimum inhibitory concentration of meropenem for 90% (MIC90) of almost all relevant gram-positive and gram-negative organisms, including Pseudomonas aeruginosa and Enterobacteriaceae . With regard to its broad spectrum, high antibacterial activity, and good penetration into ocular fluids, meropenem seems to be an alternative to currently used systemic drugs . Its usefulness in perioperative prophylaxis, as initial therapy after perforating or penetrating injuries, or in the therapy of bacterial endophthalmitis has yet to be proved.

Pediatr Infect Dis J, 1999 Oct, 18(10 Suppl), S35 - 41
Etiology of serious infections in young Gambian infants; Mulholland EK et al.; BACKGROUND: Despite improvements in infant mortality rates in many developing countries including The Gambia, neonatal mortality remains high and many neonatal deaths are caused by infection . The study described in this paper was conducted to determine the bacterial and viral etiology of serious infections in Gambian infants younger than 91 days old . METHODS: At a first level health facility 497 infants with symptoms that could indicate serious infection were enrolled, of whom 239 with 1 or more signs of serious infection and 55 with no signs were investigated, yielding 17 cases with positive bacterial cultures of blood and/or cerebrospinal fluid . At a nearby pediatric referral hospital 198 infants were seen and 182 were investigated, yielding 35 positive bacterial cultures . RESULTS: There were 15 culture positive cases of meningitis caused by Streptococcus pneumoniae (7), Streptococcus pyogenes (2), Enterobacter cloacae (2), Escherichia coli (1), Haemophilus influenzae type b (1), Streptococcus agalactiae (1) and Salmonella spp . (1) . Six of these children died . Thirty-three infants without meningitis had positive blood cultures for Staphylococcus aureus (17), S . pneumoniae (3), Salmonella spp . (5), E . coli (3), other enterobacteria (4) and S . agalactiae (1), of whom 14 died . Nasopharyngeal aspirates from 438 children were investigated for common respiratory viruses . Respiratory syncytial virus was found in 51, influenza A in 46, influenza B in 22, parainfluenza in 26 and adenovirus in 16 . Respiratory syncytial virus and influenza A isolates were found most frequently toward the end of the wet season . Nasopharyngeal carriage of S . pneumoniae and H . influenzae was studied in 320 infants recruited during the first year . Of these 184 (58%) were positive for S . pneumoniae and 141 (44%) were positive for H . influenzae, 18 of which were type b . Infants with a bacterial isolate from blood or cerebrospinal fluid were more likely than the rest to die, whereas those with a viral isolate were less likely to die . CONCLUSIONS: The most important causes of serious infections in young Gambian infants are Staphylococcus aureus, S . pneumoniae and Salmonella spp.

Clin Infect Dis, 1999 Sep, 29(3), 595 - 607
Survey of bloodstream infections due to gram-negative bacilli: frequency of occurrence and antimicrobial susceptibility of isolates collected in the United States, Canada, and Latin America for the SENTRY Antimicrobial Surveillance Program, 1997; Diekema DJ et al.; During 1997, a total of 4,267 nosocomial and community-acquired bloodstream infections due to gram-negative organisms were reported from SENTRY hospitals in Canada (8 sites), the United States (30 sites), and Latin America (10 sites) . Escherichia coli was the most common isolate (41% of all gram-negative isolates), followed by Klebsiella species (17.9%), Pseudomonas aeruginosa (10.6%), and Enterobacter species (9.4%) . For all gram-negative isolates combined, the most active antimicrobials tested were meropenem, imipenem, and cefepime . The quinolones levofloxacin (MIC90, 2 microg/mL), ciprofloxacin (MIC90, 1 microg/mL), gatifloxacin (MIC90, 2 microg/mL), sparfloxacin (MIC90, 2 microg/mL), and trovafloxacin (MIC90, 2 microg/mL) were also active against most isolates . Bloodstream infection isolates from Latin America were uniformly more resistant to all classes of antimicrobial agents tested than were isolates from Canada or the United States . Resistance phenotypes consistent with extended-spectrum beta-lactamase production were also most common among E . coli and Klebsiella species from Latin America . Further investigation of the reasons for regional differences in resistance patterns is needed, as is ongoing surveillance to detect resistance trends and to guide antimicrobial use.

Diagn Microbiol Infect Dis, 1999 Sep, 35(1), 55 - 63
Characteristics of pathogens causing urinary tract infections in hospitals in North America: results from the SENTRY Antimicrobial Surveillance Program, 1997; Jones RN et al.; Urinary tract infection (UTI) is common and involves pathogens with changing susceptibility patterns . The SENTRY Antimicrobial Surveillance Program evaluates international pathogen incidence patterns to detect and manage the emergence of resistant strains . We describe the antimicrobial resistance patterns among 1617 pathogens recovered from UTIs during the third-quarter of 1997 in North America (United States and Canada), as part of this worldwide program . The isolates were tested against more than 50 antimicrobial agents (20 reported) by reference broth microdilution methods, and selected isolates were characterized by pulsed-field gel electrophoresis (PFGE) and automated ribotyping . The five most frequently isolated species were Escherichia coli (48.6%), Enterococcus spp . (13.7%), Klebsiella spp . (12.0%), Pseudomonas aeruginosa (6.2%), and Enterobacter spp . or Proteus mirabilis (3.8% each) . For each nation, imipenem and cefepime produced the widest spectrum of coverage among the beta-lactams and amikacin was best among the aminoglycosides . For Gram-negative species, high resistance among beta-lactam antimicrobial agents was noted especially for various penicillins against E . coli (37.9% to 42.8%) and for the cephalosporins tested against enterococci (99.4% and 100%) . Approximately 7.0% of enterococci in the USA were vancomycin-resistant (88% with Van A) . P . aeruginosa provided the most consistent levels of resistance, but the following agents were most active against these organisms: amikacin (96.6 to 97.4% susceptible), tobramycin (89.5 to 100.0%), piperacillin/tazobactam (89.5 to 100.0%), piperacillin (89.5 to 96.6%), imipenem (89.7 to 92.1%), cefepime (77.6 to 89.7%), and ceftazidime (82.9 to 86.2%) . E . coli (2.2 to 2.7%), K . pneumoniae (6.2 to 6.4%), and a single Enterobacter cloacae strain produced extended-spectrum beta-lactamases; and five other Enterobacter spp . were likely to have expressed chromosomally mediated (Amp C) Stably derepressed cephalosporinases with associated resistance to ceftazidime (16.7 to 21.2% resistance) . These data demonstrated that several UTI isolates in SENTRY hospitals have high levels of resistance to various classes of antimicrobial agents with little evidence of clonal dissemination.

Biochemistry, 1999 Oct 5, 38(40), 13162 - 9
Lysine 22 in UDP-N-acetylglucosamine enolpyruvyl transferase from Enterobacter cloacae is crucial for enzymatic activity and the formation of covalent adducts with the substrate phosphoenolpyruvate and the antibiotic fosfomycin; Samland AK et al.; UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) catalyzes the first committed step in the biosynthesis of the bacterial cell wall component peptidoglycan . The enzyme is the target of the antibiotic fosfomycin . A lysine residue (K22), strictly conserved in MurAs and the structurally and mechanistically related 5-enolpyruvylshikimate 3-phosphate synthases (EPSPS), is located near the active center of the enzyme . This residue is thought to be involved directly in the binding of the substrate phosphoenolpyruvate (PEP) and also to participate in the conformational change leading to the formation of the catalytically competent enzyme complex . Using site-directed mutagenesis, we have replaced this lysine with arginine (K22R), valine (K22V), and glutamate (K22E) . These mutant proteins were expressed, purified, and characterized in comparison to wild-type MurA and a previously described inactive C115S mutant protein . It was found that all three K22 mutant proteins had less than 0.5% of the wild-type activity . Using isothermal titration calorimetry, it could be shown that the binding parameters for the UDP-sugar nucleotide substrate are not affected by the mutations, except for the K22E mutant protein . Similarly, binding of PEP was found to be unaffected in the K22 mutant proteins as demonstrated by tryptophan fluorescence quench titrations . On the other hand, the level of formation of a covalent adduct with either PEP or fosfomycin with the thiol group of cysteine 115 was diminished . The propensity to form an adduct with PEP decreased in the following order: wild type >> K22R > K22V > K22E . A comparable effect was found on the formation of the inhibitory covalent adduct of MurA and the antibiotic fosfomycin . These results are discussed in terms of an involvement of lysine 22 in a conformational change of MurA.

J Food Prot, 1999 Oct, 62(10), 1103 - 10
Development and use of polymerase chain reaction for the specific detection of Salmonella Typhimurium in stool and food samples; Lin JS et al.; Salmonella Typhimurium is one of the most important Salmonella serovars that may cause foodborne disease and human salmonellosis infection . Detection of this organism in the clinical samples of persons with gastroenteritis and the food samples associated with such persons may allow us to trace the cause of disease . Because malic acid dehydrogenase, an enzyme of the citric acid cycle, is common to organisms, the gene (mdh) coding for this enzyme was selected for the design of Salmonella Typhimurium-specific polymerase chain reaction (PCR) primers . By comparison of the mdh gene sequences of Salmonella Typhimurium and other Salmonella serotypes and of some isolates of other genera, two oligonucleotides were designed and used as PCR primers for the specific detection of Salmonella Typhimurium . The molecular weight of the PCR product was 261 bp as expected . Salmonella serovars other than Salmonella Typhimurium and isolates of other genera in the Enterobacteriaceae that is closely related to Salmonella did not generate any false-positive results . When this primer pair was used for the detection of Salmonella Typhimurium cells artificially inoculated into human stool specimens and food samples, such as milk and raw chicken meat, levels as low as 10(0) CFU per 0.1 g of stool specimen or per ml of milk or food homogenate could be detected if an 8- to 12-h preculture step using combined lactose-tetrathionate broth was performed prior to the PCR.

J Clin Microbiol, 1999 Nov, 37(11), 3647 - 53
Isolation, identification, and molecular characterization of strains of Photorhabdus luminescens from infected humans in Australia; Peel MM et al.; We describe the isolation of Photorhabdus (Xenorhabdus) luminescens from four Australian patients: two with multiple skin lesions, one with bacteremia only, and one with disseminated infection . One of the patients had multiple skin lesions following the bite of a spider, while the lesions in the other patient were possibly associated with a spider bite . The source of infection for the remaining two patients is unknown . As a member of the family Enterobacteriaceae, P . luminescens is unusual in that it fails to reduce nitrate and ferments only glucose and mannose . It gives negative reactions for lysine decarboxylase, arginine dihydrolase, and ornithine decarboxylase (Moeller) . The species is motile, utilizes citrate, hydrolyzes urea, and usually produces a unique type of annular hemolysis on sheep blood agar plates incubated at 25 degrees C . A weak bioluminescence is the defining characteristic . P . luminescens is an insect pathogen and is symbiotically associated with entomopathogenic nematodes . Its isolation from human clinical specimens has been reported previously from the United States . Restriction fragment length polymorphism-PCR analysis of the 16S rRNA gene demonstrated a high level of similarity among the Australian clinical strains and significant differences between the Australian clinical strains and the U.S . clinical strains . However, numerical analyses of the data suggest that the two groups of clinical strains are more similar to each other than they are to the symbiotic strains found in nematodes . This is the first report of the isolation of P . luminescens from infected humans in Australia and the second report of the isolation of this species from infected humans worldwide.

J Microbiol Methods, 1999 Oct, 38(1-2), 1 - 15
Assessment of bacterial community structure in soil by polymerase chain reaction and denaturing gradient gel electrophoresis; Gelsomino A et al.; Bacterial community structure was studied in a Flevo silt loam (FSL) soil microplot, as well as in 15 other soils, by using DNA extraction followed by molecular fingerprinting . Total community DNA was extracted and purified by a direct method, which yielded amplifiable DNA of high molecular weight for all soils . A variable region of the 16S rRNA gene was then amplified by PCR with bacterial primers, resulting in a mixture of amplicons separable via denaturing gradient gel electrophoresis (DGGE) . The DGGE profiles of FSL soil were indicative of dominant soil bacterial types, as evidenced by assessing the amplification of Enterobacter cloacae and Arthrobacter sp . targets in a soil DNA background . These targets produced barely detectable bands when present in soil DNA at roughly 5 x 10(6) genome equivalents per g dry soil, and strong bands at 27-fold higher levels . The PCR-DGGE analysis of the FSL soil was highly reproducible . Furthermore, different single versus composite topsoil samples yielded similar DGGE profiles with respect to major bands . In addition, samples taken along vertical soil cores (0-45 cm depth) revealed relative stability of the DGGE profiles . The profiles produced with DNA obtained from different aggregate size fractions of this soil were also similar with respect to the main bands . Moreover, FSL topsoil samples taken over a 1-year period (fallow soil) yielded stable profiles . These data suggested that the soil bacterial communities thus determined were dominated by a limited number of stable and ubiquitous types . The 16 soils, representing varying types and geographical locations, were assessed for differences in their bacterial DGGE profiles . There were striking differences between the profiles obtained for these soils . Evidence was found for the hypothesis that similar soil types tend to contain similar structures of the dominating bacterial types as revealed by the DGGE profiles.

East Afr Med J, 1999 Jul, 76(7), 365 - 9
In-vitro disk diffusion sensitivity of meropenem against bacterial pathogens in Harare; Obi CL et al.; OBJECTIVE: To compare the in-vitro sensitivity of meropenem with imipenem and other antibiotics against clinically significant bacteria . DESIGN: A longitudinal survey . SETTING: Department of Medical Microbiology, in a tertiary care university hospital . SUBJECTS: Specimens obtained from patients attending various clinics at tertiary care and teaching hospital in Harare . Those submitted to the Public Health Bacteriology Laboratory were analysed . MAIN OUTCOME MEASURES: Rates of resistance or susceptibility of the various bacteria to the antibiotics employed in the study . RESULTS: There was excellent in-vitro bacterial activity of meropenem against virtually all clinically significant Gram positive and Gram negative isolates when compared with other antibiotics such as imipenem, ciprofloxacin, gentamicin, penicillin, ampicillin, fusidic acid, tetracyclines, erythromycin and clindamycin (p < 0.5) . All isolates of Streptococcus pyogenes, Pseudomonas aeruginosa, Enterobacteriaceae, Neisseria meningitidis were susceptible to meropenem . Meropenem showed 99% overall in-vitro sensitivity against Gram positive and Gram negative bacteria . About 80% of staphylococci were resistant to penicillin whereas at least 20-25% of S . aureus, coagulase negative staphylococci, S . pyogenes showed resistance to ampicillin, erythromycin, gentamicin, tetracycline and clindamycin . CONCLUSION: Meropenem is not included in the list of routinely tested antibiotics in our laboratory, a major tertiary laboratory in the country . As a result of the ultra-broad spectrum of activity, we recommend its inclusion in our routine antibiotic sensitivity testing and observe that there is a great potential for meropenem in the treatment of infections caused by several genera of bacteria in our environment.

FEMS Immunol Med Microbiol, 1999 Oct, 26(1), 37 - 47
Effect of synthetic lipids on apoptosis and expression of alkaline phosphatase in B-lymphocytes: influence on lipopolysaccharide action; Souvannavong V et al.; Synthetic lipids were examined for their ability to mimic or to antagonize lipopolysaccharide (LPS) action in murine B-lymphocytes . Several recognized effects of LPS were analyzed: prevention of spontaneous apoptosis, expression of alkaline phosphatase (ALP) and stimulation of proliferation . Three synthetic lipids were used for that purpose: a lipopeptide (compound MTPP) which carries non-hydroxylated fatty acids, and is thus unrelated to LPS, and two glycolipids with hydroxylated fatty acids (compounds D2 and PPDm2-B), structurally related to the lipid A region of enterobacterial and Rhodopseudomonas LPS, respectively . We found that the ability of these lipids to induce LPS-like responses was not correlated with their structural analogy with LPS . Thus, the lipopeptide, MTPP, mimicked LPS in the three activities, whereas the glycolipid, D2, did not . In contrast, the ability of synthetic lipids to block LPS effects was correlated with their structural analogy with LPS . We thus observed that compound D2 selectively blocked LPS-induced ALP expression and that PPDm2-B selectively inhibited LPS-induced prevention of apoptosis . These synthetic lipids could therefore be useful for studying the LPS-mediated signals involved in B-cell activation and apoptosis.

J Bacteriol, 1999 Oct, 181(20), 6564 - 8
The modality of enterobacterial common antigen polysaccharide chain lengths is regulated by o349 of the wec gene cluster of Escherichia coli K-12; Barr K et al.; The assembly of the phosphoglyceride-linked form of enterobacterial common antigen (ECA(PG)) occurs by a mechanism that involves modulation of polysaccharide chain length . However, the genetic determinant of this modulation has not been identified . Site-directed mutagenesis of o349 of the Escherichia coli K-12 wec gene cluster revealed that this locus encodes a Wzz protein that specifically modulates the chain length of ECA(PG) polysaccharides, and we have designated this locus wzz(ECA) . The Wzz(ECA)-mediated modulation of ECA(PG) polysaccharide chains is the first demonstrated example of Wzz regulation involving a polysaccharide that is not linked to the core-lipid A structure of lipopolysaccharide.

J Bacteriol, 1999 Oct, 181(20), 6556 - 9
A novel gene required for rhamnose-glucose polysaccharide synthesis in Streptococcus mutans; Yamashita Y et al.; Gene rgpG is required for biosynthesis of rhamnose-glucose polysaccharide (RGP) in Streptococcus mutans . Its deduced amino acid sequence had similarity to WecA, which initiates syntheses of enterobacterial common antigen and some O antigens in Escherichia coli . Gene rgpG complemented a wecA mutation of E . coli, suggesting that rgpG may function similarly in RGP synthesis.

J Bacteriol, 1999 Oct, 181(20), 6387 - 95
Ferric enterochelin transport in Yersinia enterocolitica: molecular and evolutionary aspects; Schubert S et al.; Yersinia enterocolitica is well equipped for siderophore piracy, encompassing the utilization of siderophores such as ferrioxamine, ferrichrome, and ferrienterochelin . In this study, we report on the molecular and functional characterization of the Yersinia fep-fes gene cluster orthologous to the Escherichia coli ferrienterochelin transport genes (fepA, fepDGC, and fepB) and the esterase gene fes . In vitro transcription-translation analysis identified polypeptides of 30 and 35 kDa encoded by fepC and fes, respectively . A frameshift mutation within the fepA gene led to expression of a truncated polypeptide of 40 kDa . The fepD, fepG, and fes genes of Y . enterocolitica were shown to complement corresponding E . coli mutants . Insertional mutagenesis of fepD or fes genes abrogates enterochelin-supported growth of Y . enterocolitica on iron-chelated media . In contrast to E . coli, the fep-fes gene cluster in Y . enterocolitica consists solely of genes required for uptake and utilization of enterochelin (fep) and not of enterochelin synthesis genes such as entF . By Southern hybridization, fepDGC and fes sequences could be detected in Y . enterocolitica biotypes IB, IA, and II but not in biotype IV strains, Yersinia pestis, and Yersinia pseudotuberculosis strains . According to sequence alignment data and the coherent structure of the Yersinia fep-fes gene cluster, we suggest early genetic divergence of ferrienterochelin uptake determinants among species of the family Enterobacteriaceae.

Poult Sci, 1999 Sep, 78(9), 1292 - 9
Effects of dietary fat type and xylanase supplementation to rye-based broiler diets on selected bacterial groups adhering to the intestinal epithelium . on transit time of feed, and on nutrient digestibility; Danicke S et al.; Two experiments were conducted to examine the effects of different fat types, i.e., soybean oil (S) and beef tallow (T), in rye-based broiler diets, either unsupplemented (-) or supplemented (+) with xylanase (Avizyme 1300 at 1 g/kg diet), on selected bacterial groups adhering to the epithelium of crop, duodenum, jejunum, and ileum (Experiment 1, 16 d of age), on mean retention time (MRT) of digesta, and on digestibility of N and dry matter in successive segments of the digestive tract (Experiment 2, 24 d of age) . Live weight of enzyme-treated and S-fed chickens was significantly higher than that for unsupplemented or T-fed birds, respectively, in both experiments . In Experiment 1, a reduction in bacterial colonization from crop to duodenum was followed by a continuous increase as far as the ileum . Xylanase supplementation significantly reduced enterobacteria and total anaerobe microbes with a similar trend for Gram-positive cocci and enterococci . The latter two groups were significantly enhanced in birds fed T . In Experiment 2, xylanase supplementation resulted in a decrease in MRT in several segments of the digestive tract . This effect was most pronounced in the small intestine, where MRT of 268, 217, 241, and 209 min in groups S-, S+, T-, and T+, respectively, were measured . Apparent digestibility of N and dry matter was slightly improved by xylanase supplementation in the jejunum and ileum . Nitrogen digestibility by the terminal ileum was 80.3, 83.7, 79.4, and 82.2% for the S-, S+, T-, and T+ groups, respectively, and dry matter digestibility amounted to 61.2, 65.5, 62.1, and 64.0%, respectively.

J Antimicrob Chemother, 1999 Sep, 44(3), 309 - 18
Evolution and spread of SHV extended-spectrum beta-lactamases in gram-negative bacteria; Heritage J et al.; Resistance to beta-lactam antibiotics has been a problem for as long as these drugs have been used in clinical practice . In clinically significant bacteria the most important mechanism of resistance is the production of one or more beta-lactamases, enzymes that hydrolyse the beta-lactam bond characteristic of this family of antibiotics . Prominent among the beta-lactamases produced by the Enterobacteriaceae is the SHV family . The first reported SHV beta-lactamase had a narrow spectrum of activity . By the accumulation of point mutations at sites that affect the active site of the enzyme, a family of derivatives of SHV-1 has evolved . Derivatives of SHV-1 either have an extended spectrum of activity, capable of inactivating third-generation cephalosporins, or are resistant to beta-lactamase inhibitors . This review describes the evolution and spread of the SHV family of beta-lactamases, introducing the structure-function analysis made possible by DNA sequence analysis . It also reviews the methods used to characterize members of this family of beta-lactamases, indicating some of the difficulties involved.

Rapid Commun Mass Spectrom, 1999, 13(20), 2022 - 7
Identification of Enterobacteriaceae bacteria by direct matrix-assisted laser desorptiom/ionization mass spectrometric analysis of whole cells; Lynn EC et al.; Several members of Enterobacteriaceas were analyzed by matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectrometry (TOFMS) . Characteristic mass spectral peaks and patterns were observed in the mass range of 2 to 20 kDa . The mass peaks reported to be reproducibly observed by previous researchers, which were claimed to serve as species/strain-specific biomarkers, are consistently observed in our current study . Despite the high degree of similarity found in the MALDI mass spectra within the enteric bacteria, minor yet notable differences existed to allow their differentiation . Five spectral peaks at m/z 4364, 5380, 6384, 6856, and 9540, generated reproducibly for each genus studied here, are assigned as family-specific biomarkers for the Family Enterobacteriaceae . The mass peaks at m/z 7324, 7724, 9136, and 9253 are assigned as genus-specific biomarkers for Salmonella . Some unique biomarkers characterizing the species and strains of E . coli are also presented .

Neth J Med, 1999 Sep, 55(3), 110 - 7
Guidelines for severe community-acquired pneumonia in the western world; Vegelin AL et al.; BACKGROUND: Recently, several guidelines (ATS 1993/IDSA 1998; ERS 1998; SWAB 1998) have been issued for the initial therapy of patients with community-acquired pneumonia . In patients who fulfil the criteria for severe community-acquired pneumonia (SCAP), it was advised to start with a macrolide (active against Legionella spp . and Mycoplasma pneumoniae) in combination with an agent active against both pneumococci and Pseudomonas aeruginosa by the ATS/IDSA guidelines, while the ERS suggested starting with a second or third generation cephalosporin, in combination with either a macrolide or second generation quinolon plus or minus rifampicin . In the SWAB guidelines, no recommendations for SCAP were made . METHODS: Sixty-two cases admitted to the intensive care units of a tertiary-care university hospital with SCAP between 1992 and 1996 were studied retrospectively . The causative pathogens, clinical and laboratory characteristics of severity, antibiotic therapy and mortality were analysed . Immunocompromised patients, patients using immunosuppressive agents and patients with a malignancy were excluded . RESULTS: Indices of severe illness were widely seen and 37% developed shock while 45% required vasoactive drugs . Bilobular or multilobular abnormalities were seen in 34% of the patients . Forty-five patients (73%) required artificial respiration and 54 (87%) had an underlying disease . The overall mortality was 42% . In 41 patients (66%), a pathogen was isolated . The most frequent causes of SCAP in this study were Streptococcus pneumoniae (22 cases or 35%), Haemophilus influenzae (seven cases or 11%), Pseudomonas aeruginosa (four cases or 7%), and other Enterobacteriaceae (twice in combination with pneumococci and once with H . influenzae) . Legionella pneumophila was identified in three cases . In patients with severe chronic obstructive pulmonary disease (COPD), pneumococci were the most important pathogens six cases or 27%), followed by P . aeruginosa (14%) and H . influenzae (14%) . CONCLUSIONS: The guidelines for the management of SCAP issued by the ATS and IDSA in 1993 are only partially adequate in the Dutch setting . Coverage of P . aeruginosa would seem useful, given the fact that isolation of this pathogen has been shown to be a predictor of mortality, but only in patients with severe COPD or structural disease of the lung, and especially in patients in whom the Gram stain reveals Gram-negative rods, as is also suggested in the revised IDSA guidelines (1998) . Risk factors for P . aeruginosa could be added to the ERS guidelines . Including SCAP as a separate entity in the SWAB guidelines may be useful.

Antimicrob Agents Chemother, 1999 Oct, 43(10), 2497 - 503
Carbapenem derivatives as potential inhibitors of various beta-lactamases, including class B metallo-beta-lactamases; Nagano R et al.; A variety of 1beta-methylcarbapenem derivatives were screened to identify inhibitors of IMP-1 metallo-beta-lactamase, a class B beta-lactamase, in an automated microassay system using nitrocefin as a substrate . The structure-inhibitory-activity relationship study revealed that three types of 1beta-methylcarbapenems having benzothienylthio, dithiocarbamate, or pyrrolidinylthio moieties at the C-2 position showed good inhibitory activity . Among the compounds screened, J-110,441, having a benzothienylthio moiety at the C-2 position of 1beta-methylcarbapenem, was the most potent inhibitor of class B metallo-beta-lactamases with K(i) values of 0 . 0037, 0.23, 1.00, and 0.83 microM for IMP-1 encoded by the bla(IMP) gene, CcrA from Bacteroides fragilis, L1 from Stenotrophomonas maltophilia, and type II from Bacillus cereus, respectively . In a further characterization study, J-110,441 also showed inhibitory activity against TEM-type class A serine beta-lactamase and chromosomal class C serine beta-lactamase from Enterobacter cloacae with K(i) values of 2.54 and 0.037 microM, respectively . Combining imipenem or ceftazidime with J-110,441 had a synergistic effect on the antimicrobial activity against beta-lactamase-producing bacteria . Against the isolates of IMP-1-producing Serratia marcescens, the MICs of imipenem decreased to levels ranging from 1/64 to 1/4 in the presence of one-fourth of the MIC of J-110,441 . Against E . cloacae producing high levels of class C beta-lactamase, the MIC of ceftazidime decreased from 64 to 4 microg/ml in the presence of 4 microg of J-110,441 per ml . This is the first report to describe a new class of inhibitor of class B and class C beta-lactamases including transferable IMP-1 metallo-beta-lactamases.

Presse Med, 1999 Sep 4, 28 Suppl 1, 16 - 8
{Conclusion: what is the choice of antibiotics in adult respiratory tract infections?}; Klossek JM et al.; TREATMENT OF SINUSITIS: For both acute rhinosinusitis in patients with no past history where S . pneumoniae and H . influenzae are the main causal agents, or recurrent sinusitis in a chronic background where anaerobic bacteria are increasingly implicated, pristinamycin is one of the rare compounds which can be expected to be effective and is a treatment of choice for an empirical strategy . LOWER RESPIRATORY TRACT INFECTIONS: Besides high-risk subjects with non-microbiologically proven bronchial infection, where enterobacteriaceae could involve a pristinamycin is a useful alternative to the conventional strategy (i.e.: amoxicillin, macrolides and cotrimoxazole) in the treatment of LRT infection.

Presse Med, 1999 Sep 4, 28 Suppl 1, 3 - 5
{Epidemiology of bacterial ENT and bronchopulmonary infection in 1998}; Dellamonica P; EMPIRICAL STRATEGY: Antibiotic therapy of upper and lower respiratory tract infections is based on an empirical strategy . However, arguments favoring the probability of a given bacteria may be lacking and, since resistance of Streptococcus pneumoniae and Haemophilus influenzae against conventional antibiotics is becoming increasingly frequent, therapeutic strategies must be revisited . SINUSITIS: H . influenzae and S . pneumoniae are the most frequent causal agents in acute maxillary sinusitis . For chronic sinusitis, beta-lactamase producing anaerobic bacteria, S . aureus and peni-resistant pneumococci and H . influenzae must also be considered . ACUTE EXACERBATIONS OF CHRONIC BRONCHITIS: The main causal agents are H . influenzae and S . pneumoniae, followed by M . catarrhalis, S . aureus, enterobacteriaceae, and beta-hemolytic streptococci . COMMUNITY ACQUIRED PNEUMONIA: There are a wide range of pathogens, half of which are identified in different studies . RESISTANCES: For pneumococci, penicillin resistance is currently evidenced in 48% of the strains . For H . influenzae, 30% of the strains are ampicillin resistant.

Pathology, 1999 Aug, 31(3), 268 - 70
The detection of enzyme A of Yersinia enterocolitica by a disc diffusion method; Pham JN et al.; Yersinia enterocolitica has been described as expressing two types of chromosomal beta-lactamase, the broad spectrum enzyme A and the inducible cephalosporinase enzyme B . Nevertheless, not all Y . enterocolitica strains express both enzyme A and enzyme B; Y . enterocolitica strains of the less commonly isolated biotype 2, serotype O:5 (27) lack the enzyme A . Also, no other members of the Enterobacteriaceae have been demonstrated to produce enzyme A . Detection of this enzyme could therefore be a useful laboratory tool in distinguishing common pathogenic strains of Y . enterocolitica from other Enterobacteriaceae . A simple test by disc diffusion on agar for the recognition of enzyme A expression in Y . enterocolitica was evaluated . The test was based on the resistance to ticarcillin conferred by enzyme A and the highly effective inhibition of this enzyme by clavulanic acid . A typical additional zone of inhibition between the zones of inhibition around a ticarcillin 75 micrograms disc and an amoxycillin/clavulanate 3 micrograms disc was indicative of the presence of enzyme A . By contrast, a large zone of inhibition around the ticarcillin disc without an additional zone of inhibition, reflected the absence of enzyme A.

Eur J Clin Pharmacol, 1999 Sep, 55(7), 515 - 9
Clinical pharmacokinetics of ciprofloxacin in patients with major burns; Lesne-Hulin A et al.; OBJECTIVE: To better master the use of ciprofloxacin (CPF) in burn patients, a clinical study, including pharmacokinetics in serum and urine, was undertaken in a pathophysiologically homogeneous population of major-burn subjects.METHODS: Twelve major-burn patients who were infected with Pseudomonas aeruginosa, enterobacteria and gram-positive cocci, received CPF (600 mg t.i.d.) . The mean body surface area affected by third-degree burns was 31.8 +/- 14.5% . Two series of blood samples were drawn after the first and seventh doses; urine was collected during the first infusion . Levels of CPF in serum and urine were measured by means of high-performance liquid chromatography . A non-compartmental method was used for kinetic and graphic analysis of concentration-time pairs.RESULTS: No adverse effects were noted . Trough concentrations measured on day 3 (mean +/- SD) were above the minimum inhibitory concentration (MIC) for the organism responsible for infection; i.e., 2.0 +/- 1.2 microg . ml(-1), and maximum concentrations were high 9 . 9 +/- 3.4 microg . ml(-1) . An area under the concentration-time curve (AUC)/MIC ratio above 125 SIT(-1) (where SIT is the serum inhibitory titer), which has been strongly correlated with clinical response and time to bacterial eradication, was achieved in 11 patients with a MIC of 0.5 microg . ml(-1) . There was a statistically significant difference between C(min) and AUC determined on day 1 and day 3 . In contrast to healthy volunteers, CPF clearance rates were notably decreased.CONCLUSION: The pharmacokinetics of CPF was altered in major-burn patients . The recommended dosage regimen for administration of CPF, i.e . 600 mg t.i.d . shows no adverse effects and a good microbiological efficacy.

Infect Control Hosp Epidemiol, 1999 Sep, 20(9), 598 - 603
Outbreak of Enterobacter cloacae related to understaffing, overcrowding, and poor hygiene practices; Harbarth S et al.; OBJECTIVE: To determine the cause and mode of transmission of a cluster of infections due to Enterobacter cloacae . DESIGN AND SETTING: Retrospective cohort study in a neonatal intensive-care unit (NICU) from December 1996 to January 1997; environmental and laboratory investigations . SUBJECTS: 60 infants hospitalized in the NICU during the outbreak period . MAIN OUTCOME MEASURES: Odds ratios (OR) linking E . cloacae colonization or infection and various exposures . All available E . cloacae isolates were typed and characterized by contour-clamped homogenous electric-field electrophoresis to confirm possible cross-transmission . RESULTS: Of eight case-patients, two had bacteremia; one, pneumonia; one, soft-tissue infection; and four, respiratory colonization . Infants weighing <2,000 g and born before week 33 of gestation were more likely to become cases (P<.001) . Multivariate analysis indicated that the use of multidose vials was independently associated with E . cloacae carriage (OR, 16.3; 95% confidence interval {CI95}, 1.8-infinity; P=.011) . Molecular studies demonstrated three epidemic clones . Cross-transmission was facilitated by understaffing and overcrowding (up to 25 neonates in a unit designed for 15), with an increased risk of E . cloacae carriage during the outbreak compared to periods without understaffing and overcrowding (relative risk, 5.97; CI95 2.2-16.4) . Concurrent observation of healthcare worker (HCW) handwashing practices indicated poor compliance . The outbreak was terminated after decrease of work load, increase of hand antisepsis, and reinforcement of single-dose medication . CONCLUSIONS: Several factors caused and aggravated this outbreak: (1) introduction of E . cloacae into the NICU, likely by two previously colonized infants; (2) further transmission by HCWs' hands, facilitated by substantial overcrowding and understaffing in the unit; (3) possible contamination of multidose vials with E . cloacae . Overcrowding and understaffing in periods of increased work load may result in outbreaks of nosocomial infections and should be avoided.

Trends Microbiol, 1999 Oct, 7(10), 410 - 3
The mar regulon: multiple resistance to antibiotics and other toxic chemicals; Alekshun MN et al.; The chromosomal multiple antibiotic resistance (mar) locus of Escherichia coli and other members of the Enterobacteriaceae controls resistance to multiple, structurally unrelated compounds including antibiotics, household disinfectants, organic solvents and other toxic chemicals . The Mar phenotype is induced following exposure to a variety of chemicals with aromatic rings.

Pediatr Neurosurg, 1999 Jun, 30(6), 310 - 1
Subdural empyema complicating cerebrospinal fluid shunt infection; Dickerman RD et al.; Subdural empyema has not been reported previously as a complication of cerebrospinal fluid (CSF) shunt surgery . An infant submitted to CSF shunt insertion for congenital hydrocephalus developed subdural empyema after a failed attempt to treat a superficial scalp wound infection with oral antibiotics . Enterobacter cloacae was isolated from the empyema . Temporizing management of the preceding superficial wound infection with oral antibiotics probably was the cause of this exotic pathogen . The treatment of infected scalp wounds contiguous with shunt hardware must be surgical.

Drugs, 1999 Sep, 58(3), 405 - 27
Antibiotics in neonatal infections: a review; Fanos V et al.; The bacteria most commonly responsible for early-onset (materno-fetal) infections in neonates are group B streptococci, enterococci, Enterobacteriaceae and Listeria monocytogenes . Coagulase-negative staphylococci, particularly Staphylococcus epidermidis, are the main pathogens in late-onset (nosocomial) infections, especially in high-risk patients such as those with very low birthweight, umbilical or central venous catheters or undergoing prolonged ventilation . The primary objective of the paediatrician is to identity all potential cases of bacterial disease quickly and begin antibacterial treatment immediately after the appropriate cultures have been obtained . Combination therapy is recommended for initial empirical treatment in the neonate . In early-onset infections, an effective first-line empirical therapy is ampicillin plus an aminoglycoside (duration of treatment 10 days) . An alternative is ampicillin plus a third-generation cephalosporin such as cefotaxime, a combination particularly useful in neonatal meningitis (mean duration of treatment 14 to 21 days), in patients at risk of nephrotoxicity and/or when therapeutic monitoring of aminoglycosides is not possible . Another potential substitute for the aminoglycoside is aztreonam . Triple combination therapy (such as amoxicillin plus cefotaxime and an aminoglycoside) could also be used for the first 2 to 3 days of life, followed by dual therapy after the microbiological results . In late-onset infections the combination oxacillin plus an aminoglycoside is widely recommended . However, vancomycin plus ceftazidime (+/- an aminoglycoside for the first 2 to 3 days) may be a better choice . Teicoplanin may be a substitute for vancomycin . However, the initial approach should always be modified by knowledge of the local bacterial epidemiology . After the microbiological results, treatment should be switched to narrower spectrum agents if a specific organism has been identified, and should be discontinued if cultures are negative and the neonate is in good clinical condition . Penicillins and third-generation cephalosporins are generally well tolerated in neonates . There is controversy regarding whether therapeutic drug monitoring of aminoglycosides will decrease toxicity (particularly renal damage) in neonates, and on the efficacy and safety of a single daily dose versus multiple daily doses of these drugs . Toxic effects caused by vancomycin are uncommon, but debate still exists over the need for therapeutic drug monitoring of this agent . When antibacterials are used in neonates, accurate determination of dosage is required, particularly for compounds with a low therapeutic index and in patients with renal failure . Very low birthweight infants are also particularly prone to antibacterial-induced toxicity.

Ann Pharmacother, 1999 Sep, 33(9), 960 - 7
Polymyxin B sulfate and colistin: old antibiotics for emerging multiresistant gram-negative bacteria; Evans ME et al.; BACKGROUND: Polymyxin B sulfate and colistin, also known as colistimethate, have not been used for many years because less toxic antimicrobials are available . Gram-negative bacteria that are resistant to the aminoglycosides, beta-lactams, and fluoroquinolones are becoming more common . These bacteria are often susceptible to the polymyxins . OBJECTIVE: To present a review of the chemistry, antibacterial spectrum, dosing, pharmacokinetics, toxicity, and indications for polymyxin B sulfate and colistin . DATA SOURCE: A MEDLINE search (1966-1998) of the English-language literature was performed to identify primary literature on the polymyxins . Older citations ( 1949-1965) were identified through the bibliographies of these articles . STUDY SELECTION: All available reports of in vitro antibacterial activity, animal and clinical trials, and case reports were reviewed . DATA SYNTHESIS: The polymyxins are amphipathic molecules that interact with lipopolysaccharide in the bacterial outer membrane . They have potent antiendotoxic properties and antibacterial activity against Pseudomonas aeruginosa and many of the Enterobacteriaceae . Polymyxin B and colistin are usually given at a dose of 1.5-2.5 and 5 mg/kg/d, respectively, in two divided doses . Dosing must be altered in renal failure since the kidney is the primary route of elimination . Distribution into pleural fluid, joints, and cerebrospinal fluid is poor . Toxic effects involve the kidney and central nervous system . The polymyxins are recommended for serious systemic infections caused by gram-negative bacteria that are resistant to other agents . CONCLUSIONS: Polymyxin B sulfate and colistin have a role in the therapy of multidrug-resistant gram-negative bacterial infections.

Folia Microbiol (Praha), 1999, 44(1), 15 - 8
A simple method for the isolation and purification of L-asparaginase from Enterobacter aerogenes; Mukherjee J et al.; L-Asparaginase from Enterobacter aerogenes was purified by a simple method involving sonication of the crude cell mass, gel filtration with Sephacryl S-100 as the separating material, followed by ultrafiltration . Recent methods involve complex purification procedures of 5-6 steps . The isolation process resulted in 10-fold purification of the enzyme with a specific activity of 55 IU/mg protein and recovery of 54% . The purity was tested by capillary electrophoresis, used for the first time for documenting the purification of L-asparaginase . The choice of the column material was critical in the purification process.

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