Enterobacteriacea

Am J Vet Res, 1996 Jan, 57(1), 39 - 42
Epidemiological characteristics of bovine clinical mastitis caused by Staphylococcus aureus and Escherichia coli studied by DNA fingerprinting; Lam TJ et al.; OBJECTIVE: To study the epidemiology of clinical mastitis caused by Escherichia coli and Staphylococcus aureus by differentiating isolates with DNA fingerprinting techniques, using polymerase chain reaction . DESIGN: Milk samples were collected from cases of clinical mastitis in dairy cows . Escherichia coli and S aureus isolates from these cases were compared within and between cows and herds . SAMPLE POPULATION: Seven dairy herds with an average bulk milk somatic cell count < 150,000/ml, and incidence of cows with clinical mastitis of > 25%/y . PROCEDURE: Chromosomal DNA was isolated from E coli and S aureus strains isolated from cases of clinical mastitis, and amplified by polymerase chain reaction, using enterobacterial repetitive intergenic consensus primers for E coli and a random amplified polymorphic DNA primer for S aureus . Escherichia coli and S aureus strains were identified and differentiated, using their DNA polymorphism pattern . RESULTS: Multiple E coli genotypes were found in each of the herds . Persistent infections with E coli were sporadic . Only a limited number of different S aureus genotypes was found in each of the herds studied . Recurrent cases of S aureus mastitis were found in 25% of quarters with clinical S aureus mastitis . Comparing S aureus isolates from different herds indicated that 1 S aureus genotype was most prevalent . CONCLUSIONS: Because different quarters were infected with different genotypes, it was concluded that E coli is an environmental pathogen, and does not generally spread from quarter to quarter . The hypothesis that S aureus mastitis is a contagious disease, spreading from infected to uninfected quarters, could not be rejected.

J Mal Vasc, 1996, 21 Suppl A, 152 - 7
{Treatment of an exposed femorol-popliteal bypass: ex-situ replacement}; Gouny P et al.; From December 1990 to July 1995 we performed 171 sub-inguinal revascularizations including 35 popliteal revascularizations and 146 revascularizations of an artery in the leg or foot . Five cases of infection were observed within a delay of 7 and 25 days after the operation . There were 3 men and 2 women (mean age 78 years) . Four femoro-tibial bypasses were made for critical ischaemia (2 necroses of the toes, one eschar of the heal, one stage III) . There was one femoro-popliteal bypass which was associated with a femoro-femoral for necrosis of the toes . Two bypasses were made with polytetrafluoroethylene, one with Dacron and two with the greater saphenous vein . Signs of sepsis were bleeding in 2 patients who had a venous bypass and septicaemia in 2 patients . Local skin necrosis and/or apparently infected discharge or patent pus were seen in all patients . Staphylococcus aureus was found in 4 patients and Enterobacter cloacae in one . Revascularization was done with an extra-anatomic bypass in 4 patients and with a cryopreserved in situ allograft in 1 . Mortality was 20% and amputation rate was 40% . All exposed bypasses were infected but the severity of the infection varied depending on the causal germ, general signs and ischaemia of the limb . Conservative treatment has its limits: 1) intact anastomoses, 2) absence of bleeding, 3) patent bypass, 4) absence of generalized sepsis . Results of in situ revascularization depend on the virulence of the causal germ . Radical treatment (explanation + extra-anatomic revascularization) still has indications in infected infra-inguinal bypass surgery.

Int J Food Microbiol, 1996 Jan, 28(3), 411 - 8
Incidence of histamine-forming bacteria and histamine content in scombroid fish species from retail markets in the Barcelona area; Lopez-Sabater EI et al.; Incidence and diversity of histidine decarboxylating bacteria were determined in samples of tunafish, bonito and mackerel purchased at different retail markets . Histamine-forming bacteria occurred in a low proportion and always accounted for less than 0.1% of the total bacterial load in the fish samples studied . Similarly, histamine content in fish samples also was low ( < 25 ppm) and all of them met current histamine standards established by the European Union . Histamine was found in 83.3% of the tested tunafish samples with an average of 8.9 ppm . In contrast, none of mackerel samples and only 2 out of 12 of bonito showed detectable amounts of histamine . Morganella morganii and Klebsiella oxytoca were the most active histamine formers under experimental conditions, and produced on average 2765 and 1415 ppm of histamine, respectively, after incubation at 37 degrees C for 18 h . Some new histamine formers, such as Plesiomonas shigelloides, Enterobacter intermedium, Serratia marcescens, Serratia plymuthica and Serratia fonticola, have been identified . Especially Plesiomonas shigelloides would have an important role within histidine decarboxylating bacteria because it was the sole histamine former isolated that has frequently been associated with the marine aquatic environment . However, only 8-340 ppm of histamine was formed by these strains in laboratory trials.

Genetika, 1996 Jan, 32(1), 140 - 5
{Presence of the binding site for the ribosomal protein L10 in the untranslated leader sequence upstream from the rplJ gene in Thermotoga maritima is evidence for autogenous control of the expression of this gene}; Paton EB et al.; Comparative analysis of the structural organization of an untranslated sequence upstream from the rplJ gene in Thermotoga maritima revealed a potential binding site for the L10 ribosomal protein . The structure of the site detected is highly homologous to that of the 23S rRNA L10 target sequence . Structural organization of the potential mRNA L10 target site detected in T . Maritima is similar to that of mRNA targets of seven species of Enterobacteria and Synechocystis PCC 6803 . Additional elements of structural homology between the mRNA and rRNA L10 targets in T . maritima are also shown . Location of the target site within the rplJ mRNA leader and ability of this region to form alternative conformations show that expression of the rplJ gene is autogenously controlled by the L10 ribosomal protein.

APMIS, 1996 Jan, 104(1), 39 - 46
The adherence of oral isolates of Enterobacteriaceae to HeLa cells . An in vitro method using image analysis; Sedgley CM et al.; An in vitro model and an image analysis were designed to improve on existing quantification methods in the assessment of the adherence of Enterobacteriaceae to human epithelial cell monolayers . Adherence to HeLa cell monolayers of three oral isolates and one type strain from each of four species of Enterobacteriaceae over two incubation time periods was examined . Correction for actual cell area and a cube root transformation of the data to stabilize variance were applied . While behaviour varied between strains within species, E . cloacae was the most, and K . pneumoniae the least, adherent species irrespective of the incubation period . Increasing the incubation period from 30 min to 60 min resulted in greater adherence for E . cloacae, E . coli, and C . freundii, but not K . pneumoniae strains . The method permits the reliable measurement and valid analysis of the adherence of Enterobacteriaceae to cultured epithelial cell monolayers.

East Afr Med J, 1996 Jan, 73(1), 67 - 71
Antibiotic sensitivity pattern of prevalent bacterial pathogens in Gondar, Ethiopia; Aseffa A et al.; The prevalence and sensitivity pattern of common bacterial isolates from clinical specimens processed over one year in the bacteriology laboratory of a teaching hospital in north-west Ethiopia was investigated . Staphylococcus aureus, Escherichia coli and other enteric Gram-negative rods were the predominant pathogens cultured . Klebsiella species were responsible for a nosocomial outbreak among children in the year . The majority of the strains, irrespective of genera, were resistant to tetracycline (> 60%), co-trimoxazole (> 55%) and chloramphenicol (> 45%) . Resistance to ampicillin was seen in > 60% of isolates other than S . aureus . Sensitivity to gentamicin was high (> 89%) among S . aureus, E . coli and Pseudomonas strains . Isolates of Klebsiella, Enterobacter and Proteus were the least sensitive to the aminoglycoside . A multiplicity of antibiograms and predominance of certain multiresistant strains was observed for the prevalent species . Comparison made with reports from elsewhere in Ethiopia indicates that resistance to the commonly available (and cheaper) broad-spectrum antibiotics is a nationwide problem . A suggestion is made to enforce rational drug use before potent antibiotics are introduced under prescriber pressure.

Can J Microbiol, 1996 Jan, 42(1), 72 - 5
Levels and identities of nonrhizobial microorganisms found in commercial legume inoculant made with nonsterile peat carrier; Olsen PE et al.; Sixty samples of commercial North American legume inoculants manufactured for sale in 1994 using nonsterile peat as carrier were tested for Rhizobium (or Bradyrhizobium) content and non-Rhizobium biological contaminant load . Products of three major producers of such inoculants for sale in Canada were examined . Viable Rhizobium content varied from 5.6 x 10(5) to 8.1 x 10(9) cells/g, while the contaminant load varied from 1.8 x 10(8) to 5.5 x 10(10) cfu/g . Most of the inoculants contained more nonrhizobial organisms than they did rhizobia . Identifications were made of the most numerous nonrhizobial bacteria occurring in 100 samples of inoculants collected in 1993 and 1994 . The most commonly identified contaminant was Xanthomonas maltophilia . Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacter cloacae were also found at high levels in some products . Contaminant organisms capable of inhibiting rhizobial growth in plate culture were found in the products of all three manufacturers.

Int J Syst Bacteriol, 1996 Jan, 46(1), 173 - 82
Phylogeny of the Sphaerotilus-Leptothrix group inferred from morphological comparisons, genomic fingerprinting, and 16S ribosomal DNA sequence analyses; Siering PL et al.; Phase-contrast light microscopy revealed that only one of eight cultivated strains belonging to the Sphaerotilus-Leptothrix group of sheathed bacteria actually produced a sheath in standard growth media . Two Sphaerotilus natans strains produced branched cells, but other morphological characteristics that were used to identify these bacteria were consistent with previously published descriptions . Genomic fingerprints, which were obtained by performing PCR amplification with primers corresponding to enterobacterial repetitive intergenic consensus sequences, were useful for distinguishing between the genera Sphaerotilus and Leptothrix, as well as among individual strains . The complete 16S ribosomal DNA (rDNA) sequences of two strains of "Leptothrix discophora" (strains SP-6 and SS-1) were determined . In addition, partial sequences (approximately 300 nucleotides) of one strain of Leptothrix cholodnii (strain LMG 7171), an unidentified Leptothrix strain (strain NC-1), and four strains of Sphaerotilus natans (strains ATCC 13338T {T = type strain}, ATCC 15291, ATCC 29329, and ATCC 29330) were determined . We found that two of the S . natans strains (ATCC 15291 and ATCC 13338T), which differed in morphology and in their genomic fingerprints, had identical sequences in the 300-nucleotide region sequenced . Both parsimony and distance matrix methods were used to infer the evolutionary relationships of the eight strains in a comparison of the 16S rDNA sequences of these organisms with 16S rDNA sequences obtained from ribosomal sequence databases . All of the strains clustered in the Rubrivivax subdivision of the beta subclass of the Proteobacteria, which confirmed previously published conclusions concerning selected individual strains . Additional analyses revealed that all of the S . natans strains clustered in one closely related group, while the Leptothrix strains clustered in two separate lineages that were approximately equidistant from the S . natans cluster . This finding suggests that the tentative species "L . discophora" needs to be more clearly defined and compared with other species belonging to the genus Leptothrix.

Scand J Immunol, 1996 Jan, 43(1), 101 - 8
HLA-B27-restricted cytotoxic T lymphocyte responses to arthritogenic enterobacteria or self-antigens are dominated by closely related TCRBV gene segments . A study in patients with reactive arthritis; Duchmann R et al.; Identification of the T-cell receptors (TCR) used by synovial cytotoxic T lymphocytes (CTL) of patients with reactive arthritis (ReA) may be crucial to better understanding the pathogenetic mechanism underlying the HLA-B27 association of spondylarthropathies . The authors, therefore, sequenced 25 TCRB chains from HLA-B27-restricted CD8+ CTL clones and two clonal lines specific for self- or Yersinia enterocolitica antigen isolated from synovial fluids of 3 HLA-B27+ patients with ReA and PBL of one healthy HLA-B27+ individual . Fourteen non-HLA-B27-restricted CTL served as controls . Both autoreactive and Y . enterocolitica specific HLA-B27-restricted CTL used a highly limited set of VB genes with preferential rearrangement of three closely related VB families (VB 13, 14, 17), suggesting that these families contain a preferred site for contact with the HLA-B27 molecule . In addition, the presence of limited TCRBJ usage, limited heterogeneity in CDR3 sequences and dominant clones from individual donors among these CTL indicate that TCRB chain usage is further restricted by a limited set of peptides bound to the HLA-B27 molecule . Limited TCR usage by SF CTL of ReA patients may lay a basis for therapeutical manipulation of the T-cell response in the spondylarthropathies.

Mol Gen Genet, 1995 Dec 20, 249(6), 629 - 36
Regulation of nif gene expression in Enterobacter agglomerans: nucleotide sequence of the nifLA operon and influence of temperature and ammonium on its transcription; Siddavattam D et al.; The nucleotide sequence of a plasmid-borne 3.9 kb XhoI-SmaI fragment comprising the 3'-region of the nifM gene, the nifL and nifA genes and the 5'-region of nifB gene of Enterobacter agglomerans was determined . The genes were identified by their homology to the corresponding nif genes of Klebsiella pneumoniae . A typical sigma 54-dependent promoter and a consensus NtrC-binding motif were identified upstream of nifL . The predicted amino acid sequence of NifL showed close similarities to NifL of K . pneumoniae and Azotobacter vinelandii . However, no histidine residue was found to correspond to histidine-304 of A . vinelandii NifL, which had been proposed to be required for the repressor activity of NifL . The NifA sequence with a putative DNA binding motif (Q(x3) A(x3) G(x5)I) and an ATP binding site in the C-terminal and central domains, respectively, resembles that of other known NifA proteins . The function of the nifL and nifA genes was demonstrated in vivo using a binary plasmid system by their ability to activate a nifH promoter-lacZ fusion at different temperatures and concentrations of NH4+ . Maximal promoter activity occurred at 25 degrees C, and it appears that the sensitivity of NifA to elevated temperatures is independent of NifL . The expression of nifL inhibited promoter activity in the presence of NifA when the initial NH4+ concentration in the medium exceeded 4 mM.

Eur J Biochem, 1995 Dec 15, 234(3), 934 - 8
A conserved histidine residue of Escherichia coli outer-membrane phospholipase A is important for activity; Brok RG et al.; Escherichia coli outer-membrane phospholipase A (OMPLA) is thought to be a member of the class of serine hydrolases, having a classical Asp-His-Ser catalytic triad {Horrevoets, A . J . G., Verheij, H . M . & de Haas, G . H . (1991) Eur . J . Biochem . 198, 247-253} . To identify the histidine residue that is important for catalytic activity, the four histidine residues in E . coli OMPLA that are conserved in other enterobacterial OMPLA enzymes were replaced by cysteine residues using PCR-directed, site-specific mutagenesis . The resulting mutant proteins were all well expressed and displayed heat modifiability, indicating that they were properly folded . Enzyme assays showed that only the His142Cys mutant protein was lacking enzymatic activity . In addition, a His142Gly mutant protein appeared to be inactive . These results show that His142 is important for the enzymatic activity of OMPLA.

Mol Gen Genet, 1995 Dec 15, 249(5), 526 - 32
Site-specific mutagenesis in Enterobacter agglomerans: construction of nif B mutants and analysis of the gene's structure and function; Siddavattam D et al.; A novel technique was developed which may be generally well suited to the site-specific construction of mutations in Enterobacter agglomerans . The method is based on the observation that E . agglomerans can be cured of a plasmid of the incompatibility group IncQ by cultivation on citrate-containing medium . To test the applicability of this technique, we inserted a kanamycin cassette into the cloned nifB gene, transferred it into E . agglomerans, and selected for recombinants in which the wild-type nifB was replaced by the mutated gene by growing transformants on citrate medium with kanamycin . The nifB- mutants with the kanamycin cassette inserted in either orientation showed a nif- phenotype . Further, we determined the nucleotide sequence of nifB . A typical sigma 54-dependent promoter and a consensus NifA binding site were found upstream of nifB . Activation of this promoter by both heterologous and homologous NifA proteins was observed in vivo . The predicted amino acid sequence of the NifB protein showed strong similarity to the NifB sequences of other diazotrophic bacteria . The typical clustering of cysteine residues at the N-terminal end indicates its involvement in Fe-Mo cofactor biosynthesis.

J Hosp Infect, 1995 Dec, 31(4), 305 - 17
Changing patterns of susceptibilities of blood, urinary and respiratory pathogens in Hong Kong; Ho P et al.; The incidence and antimicrobial susceptibility of organisms isolated from blood, urine and respiratory specimens at a teaching hospital in Hong Kong were studied retrospectively from 1986-1993 . The incidence of Gram-positive bacteraemia, particularly coagulase-negative staphylococci (CNS), increased significantly from 33.6 to 47.3% (P < 0.001) while that of Gram-negative bacteraemia fell from 60.0 to 47.0% (P < 0.001) . Among blood isolates, methicillin resistance of CNS increased from 17.0 to 58.0% (P < 0.001) and cefuroxime resistance of Enterobacter spp . increased from 21.0 to over 50% (P < 0.01) . Among urinary isolates, cefuroxime resistance of Klebsiella spp . (11.0 to 24.0%, P < 0.001) and Enterobacter spp . (32.0 to 75.0%, P < 0.001) increased . Nalidixic acid resistance among Gram-negative urinary isolates, except Proteus mirabilis, rose by three- to sixfold . For Streptococcus pneumoniae, isolated from the respiratory tract, penicillin resistance increased dramatically (2 to 18%, P < 0.001) . For respiratory isolates of Haemophilus influenzae, ampicillin resistance increased from 17.0 to 29.0% (P < 0.001) . These data are useful in guiding empirical treatment of nosocomial infections.

Poult Sci, 1995 Dec, 74(12), 1948 - 60
Utilization of fermented flocculated poultry sludge as a feed constituent for pigs; Fransen NG et al.; Flocculated poultry sludge was mixed with 3% molasses and was flow-therm pasteurized for 5 min at a core temperature of 95 C . The sludge was subsequently cooled to between 20 and 25 C and fermented with Lactobacillus plantarum as starter culture . Three groups of eight 8- to 10-wk-old, individually housed fattening pigs (Hypor) were fed according to a fixed scheme correlated with age . One control group received a restricted ration of commercial compound feed (Group A) . The other control group was provided "nearly ad libitum" access to the same commercial compound feed (Group C) . The experimental group received the same amount of commercial compound feed as Group A, but the diet was supplemented with fermented sludge, at an inclusion rate of 19 to 28% of the total ration (DM basis) . The pigs fed the sludge-containing diet and those receiving the compound pig feed "nearly ad libitum" showed comparable growth results . It was concluded that the net energy (NEpig) level of .68 g DM of sludge was comparable to the NEpig level of 1 g compound pig feed (88% DM) . A decrease in colony counts of Enterobacteriaceae in the intestinal tract of the pigs, was regarded as positive, as it might lower the risk of disturbance of the gut flora by enteropathogenic bacteria such as Escherichia coli and Salmonella . No adverse effects on health and performance were observed as a result of the feeding of pasteurized and subsequently fermented flocculated poultry sludge to fattening pigs . It is concluded that this sludge can serve as a valuable feed constituent as long as it is processed properly.

J Antimicrob Chemother, 1995 Dec, 36(6), 975 - 85
In-vivo transfer of resistance plasmids in rat, human or pig-derived intestinal flora using a rat model; Nijsten R et al.; Germ-free rats associated with either rat- (RIF), human- (HIF) or pig-(PIF) derived Enterobacteriaceae-free intestinal flora were used for in vivo experiments to detect transfer of antibiotic resistance . Transfer of resistance was observed most frequently from the porcine donor strain to acceptor strain Escherichia coli K12, showing the highest number of transconjugants in the faeces of HIF-rats . The rats associated with the human donor strain and E . coli K12 as acceptor showed transconjugants less frequently . Only the HIF-rats yielded transconjugants on each sampling day and none at all could be isolated from the PIF-rats . Almost no transconjugants were found in the faeces of rats associated with the pig donor strain and a wild human E . coli strain as acceptor . Factors such as the nature of the donor and recipient strains as well as the origin of the intestinal flora seemed to have an influence on plasmid transfer . Transferability was highest in the HIF-rats and could be increased by administration of lincomycin . This study showed that in vivo transfer of resistance plasmids is possible in rats associated with intestinal floras of different origins . The human intestinal flora seemed to permit better transfer of resistance than that derived from the pig or the rat.

Hybridoma, 1995 Dec, 14(6), 557 - 62
Monoclonal antibodies directed against unique and common determinants on the lipopolysaccharide molecule of Salmonella serogroups A, B, and D; Merkulova TI et al.; A panel of monoclonal antibodies (MAbs) directed against lipopolysaccharide (LPS) of Salmonella serogroups A, B, and D was generated . Nine most productive hybrid clones were selected from several fusions of mouse myeloma cells with splenocytes from BALB/c mice, immunized with the corresponding heat-killed bacteria . The MAbs were characterized by enzyme immunoassay, Western blot analysis, and dot-immunoblotting with LPS and whole bacteria of Salmonella serogroups A-E and some other representatives of the Enterobacteriaceae family . Seven MAbs were reactive with the sole Salmonella strain used as an immunogen; one MAb, SD:10D9H, reacted with the five major serogroups of Salmonella species (A, B, D, E1, and E2); and one MAb, SA:5D12A, reacted with Salmonella serogroups A-E and a rough strain of S . cholerae-suis . None of the MAbs reacted with LPS of E . coli 055:B5 or whole bacteria of E . coli K12, Klebsiella pneumoniae, or Proteus vulgaris . The typical ladder-like patterns of bands were observed after immunoblotting of MAbs against electrophoretically resolved LPS from Salmonella serogroups A-E, which thus confirmed their LPS-directed specificity . MAbs affinity constants were determined by noncompetitive enzyme immunoassay using serial dilutions of both LPS as antigen (coating the plate) and antibodies . On the base of the results obtained, the presumed epitopes for each of the MAbs were discussed . The usefulness of MAbs generated for diagnostic and protective purposes was declared.

FEMS Immunol Med Microbiol, 1995 Dec, 12(3-4), 213 - 16
The production of neuraminidase and fucosidase by Helicobacter pylori: their possible relationship to pathogenicity; Dwarakanath AD et al.; The pathogenicity of enterobacteria often correlates with their production of neuraminidase (sialidase) . Forty-nine Helicobacter pylori isolates have therefore been examined for their production of neuraminidase and other glycosidases . All 49 isolates produced considerable neuraminidase (median 228 IU/microg protein, interquartile range 121-370), pH optimum 7.5 . Nine of the 49 also produced fucosidase (median 23 IU/microg protein, interquartile range 12-39), pH optimum 7.0 . Production of these enzymes did not correlate with bacterial Cag A expression or duodenal ulceration . Neutrophils exposed to neuraminidase show increased adherence to endothelium so the neuraminidase production by H . pylori could partly explain the predominant neutrophil inflammatory infiltrate seen in H . pylori-associated gastritis . Inhibition of this enzyme by use of neuraminidase-inhibitors could be a useful therapeutic approach.

J Dairy Sci, 1995 Dec, 78(12), 2745 - 52
Antigenic crossreactivity and lipopolysaccharide neutralization properties of bovine immunoglobulin G; Tomita GM et al.; We investigated a possible mechanism by which immunization against core and lipid A determinants of lipopolysaccharide reduced clinical cases of mastitis and symptoms commonly associated with heterologous Gram-negative IMI . The IgG fraction of sera from cows immunized with either Escherichia coli J5 bacterin, E . coli J5 lipopolysaccharide conjugate vaccine, or unimmunized controls was purified by precipitation with caprylic acid and ammonium sulfate . The degree of IgG crossreactivity with Gram-negative bacteria that were isolated from clinical quarters was greater than that with Gram-positive isolates of Staphylococcus aureus . The highest magnitude of crossreactivity was against smooth strain E . coli isolates, followed by heterologous species of Enterobacter, Serratia, and Klebsiella isolates . Serum IgG from cows immunized with conjugate was highly crossreactive to E . coli J5, E . coli O111:B4, Serratia marcescens, Klebsiella pneumoniae, and Salmonella typhimurium lipopolysaccharides . The magnitude of antibody crossreactivity with lipopolysaccharides coincided with the ability of IgG to suppress the mitogenic effect of lipopolysaccharides on bovine lymphocytes.

Jpn J Antibiot, 1995 Dec, 48(12), 1899 - 905
{Antimicrobial activities of clavulanic acid/ticarcillin against clinical isolates}; Koguchi M et al.; In order to investigate antimicrobial activities of clavulanic acid/ticarcillin (CVA/TIPC) against Escherichia coli, Enterobacter spp . and Pseudomonas aeruginosa in 1992 and 1994, beta-lactamase activities were analyzed and minimum inhibitory concentrations (MICs) were determined including those of the control drugs . The results are as follows; 1 . Compared to a report in 1980, the MIC distributions of CVA/TIPC against E . coli and P . aeruginosa did not show large differences . We found, however, that CVA/TIPC-resistant strains increased among Enterobacter spp . 2 . Almost all of CVA/TIPC-resistant strains of Enterobacter spp . were also resistant to cephems and new quinolones, thus they were multiple drug resistant . 3 . CVA/TIPC showed strong antimicrobial activities against penicillinase producing E . coli.

Kansenshogaku Zasshi, 1995 Dec, 69(12), 1329 - 35
{Survey bacterial isolates from blood samples during 1987-1993 in our department}; Takagi T et al.; We analyzed the changes in frequency of bacterial isolates from the blood samples in our department from May 1987 to December 1993 . 565 isolates from 4887 samples (11.6%) were detected . Among the detected microorganisms, the rate of gram-positivecocci (GPC) was much higher than the other kinds of the isolates each year . Especially, 80-90% of GPC were occupied by only 2 kinds of microorganisms, coagulase negative Staphylococci (CNS) and S . aureus . Among gram-negative-rods (GNR), constant increase of S . marcescens and transient increase of Enterobacter and P . aeruginosa were recognized . In 30 cases (5.3%), 2-3 kinds of microorganisms were isolated concomitantly, and in 55 cases (9.7%), the microorganisms, which was mainly caused by CNS, S . aureus and Candida, was isolated from both blood samples and the tip of the IVH catheter concomitantly . 42.5% of the bacterial positive cases in 1933 underwent 2 more kinds of the indwelling catheters and 48.3% were administrated antibiotics . Most of the cases had underlying diseases including mainly malignant tumor (leukemia, solid tumor), cerebrovascular diseases, and multiple injuries.

Lett Appl Microbiol, 1995 Dec, 21(6), 398 - 401
Ascorbate as an induction inhibitor of beta-lactamase in a strain of Enterobacter cloacae; Shoeb HA et al.; The effect of ascorbate and anaerobiosis of beta-lactamase content (constitutive and inducible) in relation to the susceptibility of a standard strain of Enterobacter cloacae to ampicillin was studied . Enterobacter cloacae ATCC 13047 showed increasing susceptibility to ampicillin when incubated anaerobically in the presence of increasing concentrations of ascorbic acid . The inducible beta-lactamase activity in the cell-free extracts of Ent . cloacae decreased when the bacterium was grown aerobically in the presence of ascorbic acid . Under anaerobic growth conditions, however, ascorbic acid abrogated the induction of the enzyme completely . On the other hand, the constitutive enzymatic activity was markedly decreased as the bacterium was grown anaerobically . Thus under these growth conditions ascorbate-anaerobiosis, the total beta-lactamase level in the presence of ampicillin as inducer fell below the basal constitutive activity observed in the absence of ampicillin.

Crit Care Nurs Clin North Am, 1995 Dec, 7(4), 667 - 74
Antibiotic prophylaxis in the critical care setting; Goldman MP; The prevention of infection in critically ill patients is a difficult and often frustrating task . Selective digestive decontamination may be a useful means of preventing infections in specific patient populations; however, not all critical care patients will benefit . In this article, mechanisms of antimicrobial resistance are discussed along with the consideration of specific measures to deal with this growing dilemma . Concerns about specific microorganisms, such as vancomycin-resistant enterococcus and multidrug-resistant Enterobacter species, are addressed . It is clear that the use of antimicrobial agents is not the only solution to the problem of infection in critically ill patients.

Arch Dis Child, 1995 Dec, 73(6), 549 - 51
Effects of nicotine on bacterial toxins associated with cot death; Sayers NM et al.; Toxins produced by staphylococci and enterobacteria isolated from the nasopharynx of cases of sudden infant death syndrome (SIDS) have a lethal effect when injected into chick embryos . If the toxins are progressively diluted the lethal effect disappears, but certain combinations of toxins show synergy so that if sublethal doses are mixed a highly lethal effect is produced . In this paper it is shown that nicotine at very low concentrations (less than that produced in man by 0.05 cigarettes) potentiates the lethal action of certain SIDS associated bacterial toxins and markedly potentiates the lethal action of synergistic combinations of bacterial toxins . These results could explain, at least in part, why parental smoking increases the risk of SIDS . They also provide further support for the common bacterial toxin hypothesis of cot death.

J Bacteriol, 1995 Dec, 177(24), 7245 - 54
Evidence suggesting cis action by the TnaC leader peptide in regulating transcription attenuation in the tryptophanase operon of Escherichia coli; Gish K et al.; Expression of the tryptophanase (tna) operon in Escherichia coli is regulated by catabolite repression and transcription attenuation . Elevated levels of tryptophan induce transcription antitermination at one or more Rho factor-dependent termination sites in the leader region of the operon . Induction requires translation of a 24-residue coding region, tnaC, located in the 319-nucleotide transcribed leader region preceding tnaA, the structural gene for tryptophanase . In the present paper, we show that two bacterial species that lack tryptophanase activity, Enterobacter aerogenes and Salmonella typhimurium, allow tryptophanase induction and tna operon regulation when they carry a plasmid containing the E . coli tna operon . The role of tnaC in induction was examined by introducing mutations in a 24-nucleotide segment of tnaC of E . coli surrounding and including the crucial Trp codon 12 . Some mutations resulted in a noninducible phenotype; these mostly introduced nonconservative amino acid substitutions in TnaC . Other mutations had little or no effect; these generally were in third positions of codons or introduced conservative amino acid replacements . A tryptophan-inserting, UGA-reading glutamine suppressor tRNA was observed to restore partial regulation when Trp codon 12 of tnaC was changed to UGA . Stop codons introduced downstream of Trp codon 12 in all three reading frames established that induction requires translation in the natural tnaC reading frame . Our findings suggest that the TnaC leader peptide acts in cis to prevent Rho-dependent termination.

J Bacteriol, 1995 Dec, 177(24), 7011 - 8
A system to generate chromosomal mutations in Lactococcus lactis which allows fast analysis of targeted genes; Law J et al.; A system for generating chromosomal insertions in lactococci is described . It is based on the conditional replication of lactococcal pWV01-derived Ori+ RepA- vector pORI19, containing lacZ alpha and the multiple cloning site of pUC19 . Chromosomal AluI fragments of Lactococcus lactis were cloned in pORI19 in RepA+ helper strain Escherichia coli EC101 . The frequency of Campbell-type recombinants, following introduction of this plasmid bank into L . lactis (RepA-), was increased by combining the system with temperature-sensitive pWV01 derivative pVE6007 . Transformation of L . lactis MG1363 (pVE6007) with the pORI19 bank of lactococcal chromosomal fragments at the permissive temperature allowed replication of several copies of a recombinant plasmid from the bank within a cell because of the provision in trans of RepA-Ts from pVE6007 . A temperature shift to 37 degrees C resulted in loss of pVE6007 and integration of the pORI19 derivatives at high frequencies . A bank of lactococcal mutants was made in this way and successfully screened for the presence of two mutations: one in the monocistronic 1.3-kb peptidoglycan hydrolase gene (acmA) and one in the hitherto uncharacterized maltose fermentation pathway . Reintroduction of pVE6007 into the Mal- mutant at 30 degrees C resulted in excision of the integrated plasmid and restoration of the ability of ferment maltose . The integration plasmid (pMAL) was rescued by using the isolated plasmid content of a restored Mal+ colony to transform E . coli EC101 . Nucleotide sequencing of the 564-bp chromosomal fragment in pMAL revealed an internal part of an open reading frame of which the translated product showed significant homology with ATP-binding proteins MalK of E . coli, Salmonella typhimurium, and Enterobacter aerogenes and MsmK of Streptococcus mutans . This combined use of two types of conditional replicating pWV01-derived vectors represents a novel, powerful tool for chromosomal gene inactivation, targeting, cloning, and sequencing of the labelled gene.

Am J Respir Crit Care Med, 1995 Dec, 152(6 Pt 1), 1825 - 34
The role of intragastric acidity and stress ulcus prophylaxis on colonization and infection in mechanically ventilated ICU patients . A stratified, randomized, double-blind study of sucralfate versus antacids; Bonten MJ et al.; This study evaluates the effects of sucralfate and antacids on intragastric acidity, colonization of stomach, oropharynx and trachea, and the incidence of ventilator-associated pneumonia (VAP) in mechanically ventilated patients in intensive care units . We conducted a prospective randomized double-blind trial in which patients were stratified on initial gastric pH . Intragastric acidity was measured with computerized, continuous intragastric monitoring . The diagnosis of VAP was established with protected specimen brush and/or bronchoalveolar lavage . The study included consecutive eligible patients with mechanical ventilation and nasogastric tube . Interventions: After stratification on initial intragastric pH into two groups, patients from both groups were randomly assigned to receive either antacids (a suspension of aluminum hydroxide and magnesium hydroxide), 30 mL every 4 h, or sucralfate, 1 g every 4 h . Continuous intragastric pH monitoring was performed in 112 patients (58 antacids, 54 sucralfate) . Using predetermined criteria, colonization of stomach, oropharynx, and trachea, and the incidence of VAP were assessed . Altogether, 141 patients were included (74 receiving antacids, 67 sucralfate) and continuous intragastric pH monitoring was performed in 112 patients, with a mean of 75 h per patient . The median pH and the percentage of time with a pH < 4.0 were calculated from each measurement . No significant differences in median pH values (4.7 +/- 2.2 and 4.5 +/- 2.0 for antacids and sucralfate, respectively) were observed . Median pH values were higher in patients with gastric bacterial colonization than in noncolonized patients (5.5 +/- 2.1 and 3.3 +/- 2.0, p < 0.01), but colonization of oropharynx and trachea was not related to intragastric acidity . Thirty-one patients (22%) developed VAP, with a similar incidence in both treatment groups . In addition, antibiotic use, duration of hospitalization, and mortality rates were similar in both groups . Enteral feeding did not change intragastric acidity significantly but increased gastric colonization with Enterobacteriaceae, without influencing oropharyngeal and tracheal colonization . Antacids and sucralfate had a similar effect on intragastric acidity, colonization rates, and incidence of VAP . Intragastric acidity influenced gastric colonization but not colonization of the upper respiratory tract or the incidence of VAP . Therefore, it is unlikely that the gastropulmonary route is important for the development of VAP.

Plasmid, 1995 Nov, 34(3), 223 - 8
Self-transmissible nif plasmid (pEA9) of Enterobacter agglomerans 339: molecular cloning and evidence for the existence of similar nif clusters on dissimilar plasmids in Enterobacter strains; Steibl HD et al.; A cosmid library was generated to the 200-kb self-transmissible nif plasmid pEA9 isolated from Enterobacter agglomerans 339 . The cosmid clone identified to contain the complete nif cluster was used to determine the nif gene organization and the physical map . The restriction pattern and nif gene organization of this nif cluster showed remarkable similarities to the nif cluster identified on the 110-kb plasmid pEA3 of Enterobacter agglomerans 333 . Nucleotide sequence of several randomly selected regions of the nif cluster of pEA9 showed 96% similarity when compared to the known sequences of the nif cluster of pEA3 . However, the homology ended abruptly at the flanking regions of the nif clusters and no similarity could be detected with the rest of the DNA of these plasmids . This reveals the existence of similar nif clusters on dissimilar plasmids, implying the horizontal transfer of the entire nif gene cluster.

Zhonghua Nei Ke Za Zhi, 1995 Nov, 34(11), 764 - 6
{A randomized control study on the treatment of 123 cases of bacterial infections with cefteram and cefaclor}; Li G et al.; To evaluate the efficacy and the safety of cefteram in bacterial infections, a randomized control study of cefteram and cefaclor on the treatment of 123 patients with respiratory and urinary tract infections was carried out . The result showed that the effective and bacterial eradication rates were 92.1% and 91.4% for cefteram . 83.3% and 85.2% for cefalor . Adverse reactions were mainly gastrointestinal reactions, occurring in 4.6% of the cefteram group and 9.4% of the cefaclor group . Study of minimum inhibitory concentration displayed high antibacterial activity of cefteram for enterobacteriaceae and other Gram-negative organisms and its activity was higher than that of gentamyicin and ciprofloxacin for E . coli . It is concluded that cefteram was effective and safe in the treatment of respiratory and urinary tract infections.

J AOAC Int, 1995 Nov-Dec, 78(6), 1531 - 7
Detection of Salmonella spp . in eggs: DNA analyses, culture techniques, and serology; Burkhalter PW et al.; A polymerase chain reaction (PCR) method for direct detection of Salmonella spp . in whole-shell eggs is described . The method does not require isolating strains . Preenrichment, rapid DNA isolation, and a nested PCR system targeting the invA gene enabled detection of the genus Salmonella . The specific nested PCR product of 283 base pairs was formed from all 21 serovars, including 43 Salmonella strains tested . No PCR product was formed from 56 non-Salmonella enterobacteriacea and other bacterial strains tested . Experiments with artificially contaminated eggs showed a detection limit of about 10(3)-10(4) colony-forming units (cfu)/egg before and about 1-10 cfu/egg after preenrichment . In analysis of 180 single eggs from 4 flocks and 36 pools of 5 eggs each from another 4 flocks from the same producer, Salmonella spp . were detected in 5 of 90 eggs from 2 different flocks . Determination of anti-Salmonella antibodies in eggs yielded positive results for 2 additional and the 2 PCR-positive flocks . In contrast, classical selective culture detected Salmonella spp . in only 1 of 100 eggs in one flock when 100 eggs from each flock were analyzed.

Infection, 1995 Nov-Dec, 23(6), 384 - 7
In vitro activity of cefpirome against selected clinical enterobacterial isolates with beta-lactamase-mediated resistance; Tzouvelekis LS et al.; Previous studies have shown that there is a high incidence of resistance to cephalosporins among enterobacteria isolated in Greek hospitals . This resistance is mainly due to either the derepression of chromosomal cephalosporinases or the acquisition of plasmids coding for SHV-5 type beta-lactamase . In the present study the activity of cefpirome against a number of enterobacteria (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes and Serratia marcescens) possessing the mechanisms mentioned above was examined . Cefpirome was found active against all the strains characterized by stable derepression of chromosomal class-C enzymes . The antibiotic was less potent against strains expressing SHV-5 type beta-lactamase due to its hydrolysis by the enzyme . Also cefpirome exhibited good activity against E . aerogenes strains with reduced susceptibility to imipenem . These in vitro data suggest that cefpirome might be useful in treating infections caused by these resistant microorganisms that are frequently encountered in Greek hospitals.

Infection, 1995 Nov-Dec, 23(6), 339 - 43
Biochemical profiles and serotypes of nosocomial Enterobacter cloacae strains in Northern Norway: biochemical identification problems with commercial test systems; Andersen BM; During a period of 2 years, 118 strains of Enterobacter cloacae were collected consecutively in connection with nosocomial infections in Northern Norway; identified by conventional methods and by the API 20E system . The API 20E profile 3305573 predominated and was present in 73 of 118 strains . Among 96 serotyped strains, 73 were serotypable, 20 nontypable and two polyagglutinable . Predominating serotypes were 3 (29 strains), 8 (21 strains) and 23 (nine strains) . When the API 20E profiles of the 118 strains were read in the new ATB (automated computer-assisted) 20E data base system, 97 of 118 (82.2%) strains were identified as E . cloacae . The 118 strains were tested in the new ATB Rapid ID 32E and ATB ID 32E (ATB system, bioMerieux, France) systems . Only 69 of 118 (58.5%) strains were identified as E . cloacae in both systems . The ATB Rapid ID 32E identified 97 of 118 strains (82.2%), and the ATB ID 32E only 80 of 118 strains (67.8%) . Among 73 serotypable strains, the ATB Rapid ID 32E identified 79.5% as E . cloacae, while the ATB ID 32E identified only 64.4% . Among 40 serotypable strains with API 20E profile 3305573, all 40 were identified as E . cloacae by the ATB Rapid ID 32E, while only 27 (67.5%) by the ATB ID 32E system . Further improvements may increase the value of biochemical identification of E . cloacae in diagnostic work.

J Antimicrob Chemother, 1995 Nov, 36(5), 757 - 71
Laboratory assessment of antibacterial activity of zwitterionic 7-methoxyimino cephalosporins; Pechere JC et al.; Zwitterionic 7-methoxyimino cephalosporins (cefpirome, cefepime, cefclidin, DQ2556, FK037 and SCE2787) possess a variable substitution at C3 which contains a quarternary nitrogen . These cephalosporins display low affinities for Class I beta-lactamase and rapid penetration through the outer membrane of Gram-negative bacilli, so that an increased number of periplasmic beta-lactam molecules interact with PBP's per unit of time . As a consequence, the new zitterionic compounds remain active against some, but not all, ceftazidime-resistant Enterobacteriaceae producing high levels of Class I beta-lactamase or Bush type 2b beta-lactamases . Antipseudomonas activities are generally similar to that of ceftazidime except that cefclidin is more active . The new zwitterionic compounds, especially cefpirome and FK037, express greater antistaphylococcal potency than does ceftazidime . A variety of animal models including meningitis and endocarditis have confirmed the potential of these compounds in-vivo . On the basis of structural and antibacterial characteristics, the expression 'forth generation' is acceptable to describe the zwitterionic 7-methoxyimino cephalosporins.

Br Vet J, 1995 Nov-Dec, 151(6), 643 - 58
Salmonella fimbriae: novel antigens in the detection and control of salmonella infections; Thorns CJ; Fimbriae are thin, proteinaceous surface organelles produced by members of the Enterobacteriaceae, including most salmonellas . A number of fimbrial antigens expressed by strains of Salmonella enteritidis and S . typhimurium have now been described and characterized . However, their functions are still poorly understood, although some evidence indicates they have a role in bacterial survival in the host or external environment . Diagnostic tests based on the detection of fimbriae or specific antibodies against them have recently been developed and applied successfully to the rapid and specific identification of S . enteritidis infections . The role of salmonella fimbriae in future generations of live vaccines either as protective antigens or as the carriers of heterologous antigens is also discussed.

Antimicrob Agents Chemother, 1995 Nov, 39(11), 2580 - 2
First characterization of inhibitor-resistant TEM (IRT) beta-lactamases in Klebsiella pneumoniae strains; Lemozy J et al.; Two clinical strains of Klebsiella pneumoniae, TP 01 and TP 02, presented resistance to amoxicillin-clavulanate and were fully susceptible to cephalothin . These strains produced two beta-lactamases, SHV-1 and a TEM enzyme with a pI of 5.2 . The previously described changes Arg-244-->Cys and Arg-244-->Ser in IRT-1 and IRT-2 (A . Belaaouaj, C . Lapoumeroulie, M . M . Canica, G . Vedel, P . Nevot, R . Krishnamoorthy, and G . Paul, FEMS Microbiol . Lett . 120:75-80, 1994) were found in TEM enzymes from the TP 01 and TP 02 strains, respectively . This is the first report of inhibitor-resistant TEM (IRT) in species other than Escherichia coli from the family Enterobacteriaceae.

J Clin Microbiol, 1995 Nov, 33(11), 2856 - 8
Controlled clinical evaluation of BACTEC Plus Aerobic/F and BacT/Alert Aerobic FAN bottles for detection of bloodstream infections; Pohlman JK et al.; A total of 7,190 blood culture sets were obtained from adult patients with a suspected bloodstream infection . A 20-ml sample of blood was distributed equally between the aerobic FAN bottle which was monitored in the BacT/Alert system and a Plus Aerobic/F bottle which was monitored in the BACTEC 9240 system . A total of 988 positive cultures were obtained from 483 patients; however, only 453 positive cultures from 173 patients met the criteria for volume ( > or = ml per bottle) and clinical significance on the basis of concurrent case review required for data analysis . There were 25 and 68 false positives from the FAN and Plus Aerobic/F bottles, respectively . There were no statistically significant differences between systems in the number of positive cultures or septic episodes by species; however, the total number of Enterobacteriaceae and Pseudomonas aeruginosa isolates combined was significantly greater in the FAN bottle (P = 0.04) . Detection times did not differ significantly between systems for positive cultures; however, episodes of Staphylococcus aureus bacteremia were detected significantly more rapidly from the FAN bottle (P = 0.005) . There was no significant difference between systems in the detection of bloodstream infections in patients receiving antibiotics at the time of blood culture.

Chemotherapy, 1995 Nov-Dec, 41(6), 477 - 86
A multicenter comparative study of the in vitro activity of fleroxacin and other antimicrobial agents; Markowitz SM et al.; The in vitro activity of fleroxacin was determined by broth microdilution against 2,079 recent bacterial isolates and compared to the activities of ciprofloxacin, ofloxacin, lomefloxacin, cefaclor, cefuroxime, cefixime, ceftriaxone, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole (TMP-SMX), and, as appropriate, erythromycin and oxacillin . Most Enterobacteriaceae were inhibited by the quinolones at a concentration of < or = 1 microgram/ml; MIC90s of fleroxacin, ciprofloxacin, ofloxacin, and lomefloxacin were 0.25, 0.5, 1 and 1 micrograms/ml, respectively . Fleroxacin was 2-fold more active than ciprofloxacin against Providencia stuartii and Serratia marcescens . Aside from the quinolones, ceftriaxone and TMP-SMX were the most active antibiotics against the Enterobacteriaceae, with MIC90s of 8 and 16 micrograms/ml, respectively . Ciprofloxacin was more active against Pseudomonas aeruginosa than the other quinolones, while fleroxacin was more active against Stenotrophomonas maltophilia: 17.7, 11.2, 20.0, and 22.4% of P . aeruginosa were resistant to fleroxacin, ciprofloxacin, ofloxacin, and lomefloxacin, respectively . Moraxella catarrhalis and Haemophilus influenzae were uniformally susceptible to all antibiotics tested, as were the majority of oxacillin-susceptible staphylococci . The MIC90s of the quinolones and of the beta-lactam antibiotics for oxacillin-resistant staphylococci were 8- to 256-fold higher than for oxacillin-susceptible staphylococci . The beta-lactam antibiotics, TMP-SMX, and erythromycin were more active than the quinolones against streptococci; all antibiotics were poorly active against enterococci . Fleroxacin is active against a broad range of gram-negative bacilli and against oxacillin-susceptible staphylococci and should prove useful for such infections . However, its use cannot be recommended for infections due to oxacillin-resistant staphylococci, streptococci, or enterococci.

Appl Environ Microbiol, 1995 Nov, 61(11), 4131 - 4
Orally administered bovine lactoferrin inhibits bacterial translocation in mice fed bovine milk; Teraguchi S et al.; Feeding of bovine milk to mice induced a high incidence of bacterial translocation from the intestines to the mesenteric lymph nodes, and the bacteria involved were mainly members of the family Enterobacteriaceae . Supplementation of the milk diet with bovine lactoferrin or a pepsin-generated hydrolysate of bovine lactoferrin resulted in significant suppression of bacterial translocation . Our findings suggest that this ability of lactoferrin to inhibit bacterial translocation may be due to its suppression of bacterial overgrowth in the guts of milk-fed mice.

J Bacteriol, 1995 Nov, 177(22), 6411 - 21
Molecular cloning, mapping, and regulation of Pho regulon genes for phosphonate breakdown by the phosphonatase pathway of Salmonella typhimurium LT2; Jiang W et al.; Two pathways exist for cleavage of the carbon-phosphorus (C-P) bond of phosphonates, the C-P lyase and the phosphonatase pathways . It was previously demonstrated that Escherichia coli carries genes (named phn) only for the C-P lyase pathway and that Enterobacter aerogenes carries genes for both pathways (K.-S . Lee, W . W . Metcalf, and B . L . Wanner, J . Bacteriol . 174:2501-2510, 1992) . In contrast, here it is shown that Salmonella typhimurium LT2 carries genes only for the phosphonatase pathway . Genes for the S . typhimurium phosphonatase pathway were cloned by complementation of E . coli delta phn mutants . Genes for these pathways were proven not to be homologous and to lie in different chromosomal regions . The S . typhimurium phn locus lies near 10 min; the E . coli phn locus lies near 93 min . The S . typhimurium phn gene cluster is about 7.2 kb in length and, on the basis of gene fusion analysis, appears to consist of two (or more) genes or operons that are divergently transcribed . Like that of the E . coli phn locus, the expression of the S . typhimurium phn locus is activated under conditions of Pi limitation and is subject to Pho regulon control . This was shown both by complementation of the appropriate E . coli mutants and by the construction of S . typhimurium mutants with lesions in the phoB and pst loci, which are required for activation and inhibition of Pho regulon gene expression, respectively . Complementation studies indicate that the S . typhimurium phn locus probably includes genes both for phosphonate transport and for catalysis of C-P bond cleavage.

Curr Microbiol, 1995 Nov, 31(5), 287 - 90
Isolation of Ewingella americana from mollusks; Muller HE et al.; Twenty-three of 2446 strains of Enterobacteriaceae isolated from mollusks were identified as Ewingella americana both biochemically and by DNA hybridization with strain S6/1111 . The biochemical characteristics of the new strains showed few differences from previously reported strains obtained from human clinical specimens . These are the first strains of E . americana isolated from animals.

FEMS Microbiol Lett, 1995 Oct 15, 132(3), 259 - 62
Membrane hyperpolarisation by valinomycin and its limitations for bacterial viability assessment using rhodamine 123 and flow cytometry; Porter J et al.; The ionophore, valinomycin, was investigated as a possible means of bacterial viability assessment using the fluorescent membrane potential dye rhodamine 123 . Membrane hyperpolarisation in Escherichia coli, Pseudomonas fluorescens, Enterobacter aerogenes and Arthrobacter globiformis was examined during exponential growth and during stress by brief starvation in a high sodium, low potassium buffer using flow cytometric analysis of rhodamine 123 uptake . Dye uptake was variable both between species and amongst cells from the same culture . Exponential phase cells showed no increase in dye uptake due to valinomycin treatment . Stressed P . fluorescens cells responded to valinomycin treatment by increased dye uptake, while stressed E . coli and A . globiformis cells showed no response . Approximately 50% of stressed Eb . aerogenes cells responded to valinomycin . The results demonstrate the limitations of rhodamine dye for viability analysing the viability of diverse bacterial communities and underline the degree of cell heterogeneity in batch cultures.

Biochim Biophys Acta, 1995 Oct 5, 1258(3), 225 - 7
Occurrence of a furan fatty acid in marine bacteria; Shirasaka N et al.; A fatty acid containing a furan ring was detected in the cellular lipids of marine bacteria, Shewanella putrefaciens, Marinomonas comunis, Enterobacter agglomerans, Pseudomonas fluorescens, etc., which were isolated from the intestinal liquor of fishes . Analytical data indicated that the fatty acid was 10,13-epoxy-11-methyloctadeca-10, 12-dienoic acid . Therefore, we propose that furan fatty acids detected in marine fish are derived not only from marine plants but also from intestinal bacteria of fishes.

Microb Drug Resist, 1995 Fall, 1(3), 195 - 202
Molecular epidemiology of integron-associated antibiotic resistance genes in clinical isolates of enterobacteriaceae; Sallen B et al.; The epidemiology of integron-mediated antibiotic-resistant genes in clinical enterobacteria from a single location was investigated . Forty-nine isolates (kindly provided by Dr . D . Sirot, Clermont-Ferrand, France) were selected for transferable resistance to aminoglycosides or to other antibiotics . Total DNA prepared from these strains was screened for the presence of conserved segments of integrons by PCR . The nature and frequency of inserted resistance gene cassettes were determined by direct nucleotide sequencing and were related to the resistances expressed by the strain . Integron hot-spots were present in 59% of the strains from 6 species, in either one or two copies . For amplicons sequenced, one or two antibiotic-resistant genes were found in various combinations, and were always expressed at the phenotypic level . They included the aminoglycoside resistance genes ant(3")-Ia and aac(6')-Ib (75%), as well as dhfr-I,-VII (21.4%) and blaOXA-1 (3.6%) . Almost half of the transferable resistance to aminoglycosides (53%) was mediated by integron hot-spots in strains characterized at the nucleotide level . The proportion rose to 100% for the AAC(6')-I resistance profile . This study emphasizes the important contribution of integrons to aminoglycoside resistance within enterobacteria from a clinical setting.

Plant Foods Hum Nutr, 1995 Oct, 48(3), 185 - 92
Studies on samh seeds (Mesembryanthemum forsskalei Hochst) growing in Saudi Arabia: 2: Chemical composition and microflora of samh seeds; Al-Jassir MS et al.; The chemical composition of samh seeds have been investigated . Proximate analysis showed a composition of 22.25% protein, 5.7% moisture, 5.6% fat, 4.0% ash, 9.7% crude fiber, and the remainder being total carbohydrates . Mineral element analysis revealed that potassium, magnesium, sodium and calcium were present as the major elements . Iron, manganese, zinc and copper were found at lower levels . However, lead was not detected in the samh seeds . Gas-liquid chromatographic analysis of the methylester of the fatty acids of the samh seeds oil revealed the presence of fourteen fatty acids . Linoleic and oleic acids were the principle unsaturated fatty acids . While palmitic acid was the main saturated fatty acid . Amino acid analysis of the samh seeds showed the presence of seventeen amino acids including eight essential amino acids . Glutamic acid, arginine, and aspartic acid were the major amino acids . Cystine and proline were present in trace amounts . These results some of which have not been reported elsewhere indicate the high nutritional potential of Saudi samh seeds . The total aerobic bacterial count and total sporeformers of seeds were 19 x 10(7) and 5 x 10(4) cfu/g respectively, thus the enterobacteriaceae, B cereus and yeast and molds were 5 x 10(2), 1 x 10(2) and 7 x 10(2) respectively . The seeds were Staph . free and the samh extract had no antimicrobial effect.

Zhonghua Bing Li Xue Za Zhi, 1995 Oct, 24(5), 285 - 7
{A pathological comparison between Hirschsprung's enterocolitis and neonate necrotizing enterocolitis}; Zhang Z et al.; Autopsy records of 9 cases of neonate Hirschsprung's enterocolitis (HD) and 16 cases of neonate necrotizing enterocolitis (NEC) were analysed . It was found that the NEC lesions were more extensive than HD lesions, the bleeding and inflammation in NEC were also more serious than in HD . From our 21 animal experiments in which we tried to clarify the pathogenesis of Hirschsprung's enterocolitis and NEC, our preliminary hypothesis fro the development of Hirschsprung's enterocolitis being: the distal segment was first obstructed, causing the proximal segment to expand, the increase of pressure within the bowel resulted in ischemia of the intestines, increased bacterial multiplication in the retained feces and bacterial infiltration of the intestinal mucosa . The above being the major cause of HD . When the neonate is in asphyxia or shock, ischemia of the intestines and immunoallergic reactions occur, due to the lack of IgA in the mucosa, the multiplication and infiltration of pathogenic enterobacteria in the intestinal wall results in NEC.

Clin Infect Dis, 1995 Oct, 21(4), 915 - 23
Molecular epidemiology of an SHV-5 extended-spectrum beta-lactamase in enterobacteriaceae isolated from infants in a neonatal intensive care unit; Venezia RA et al.; Klebsiella oxytoca that produced extended-spectrum beta-lactamase (ESBL) and were resistant to ceftazidime were isolated from infants in a neonatal intensive care unit (NICU) . During a 30-week period, 3 infants developed infections and an additional 60 infants were colonized with these bacteria . The molecular typing data suggested transmission of a single strain of ceftazidime-resistant K . oxytoca among 48 of the 63 infants . The ESBL of 46 of the 48 similar isolates, 14 of the remaining 15 isolates, and 6 other Enterobacteriaceae appeared to be associated with a conjugative plasmid of approximately 85 kb . The ESBL gene was cloned, and DNA sequencing confirmed that the ESBL was an SHV-5 . Hybridization data suggested that the SHV-5 gene was transmitted to other Enterobacteriaceae in vivo . The spread of the ESBL was reduced through adherence to infection control practices.

J Vet Diagn Invest, 1995 Oct, 7(4), 506 - 8
Evaluation of a commercial automated system and software for the identification of veterinary bacterial isolates; Patten VH et al.; A commercial gram-negative bacterial autoidentification plate was originally developed using bacterial isolates of human origin . Three veterinary diagnostic laboratories conducted a 2-phase trial to enhance the database for veterinary use . The first phase consisted of testing the plate with 447 bacterial isolates of veterinary origin and incorporating that data into the existing database . Emphasis was placed on the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, since the Pseudomonas taxon was quite complete . The second phase of the trial consisted of evaluating the enhanced database using 270 clinical veterinary isolates normally encountered in veterinary laboratories . For the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, 72% of the bacterial isolates were identified correctly to genus and 85% to species after 18 hours incubation . All identifications in phase 1 and phase 2 were confirmed using conventional methods.

New Microbiol, 1995 Oct, 18 Suppl, 19S - 31S
{Preclinical evaluation of meropenem, a new parenteral carbapenem}; Edwards JR; Meropenem is a new carbapenem antibiotic that is stable to human renal dehydropeptidase-I (DHP-I) and exhibits potent bactericidal activity against almost all clinically significant aerobic and anaerobic bacteria . Activity is achieved through rapid entry into bacteria, resisting hydrolysis by all serine-based beta-lactamases, both of chromosomal or plasmid origin, and high affinity for vital penicillin binding proteins . The antibacterial spectrum of meropenem has been investigated extensively in a world-wide programme of studies . The results from all of these studies are consistent and identify in vitro differences between meropenem and imipenem . Both agents demonstrate high activity against Gram-positive aerobes with meropenem slightly less active than imipenem but significantly more potent than imipenem against Haemophilus influenza, all Enterobacteriaceae and 2-4 fold more active against Pseudomonas aeruginosa and most other pseudomonas . The spectrum of carbapenems is superior to that of all other beta-lactams . This is achieved, in part, by stability to the chromosomal beta-lactamases which hydrolyse ceftazidime, cefotaxime and ceftriaxone and against which newer agents like cefpirome and cefepime are not fully stable . Meropenem is also stable to the new plasmid-mediated enzymes which are responsible for significant elevation of MIC's of all cephalosporins and penicillins . When tested against P . Aeruginosa which have become resistant to imipenem therapy, these strains remained susceptible to meropenem . The activity of meropenem against anaerobes is at least as potent as metronidazole and clindamycin . These impressive in vitro data have been the basis for an extensive clinical evaluation programme in many indications including infections caused by single or multiple pathogens.

New Microbiol, 1995 Oct, 18 Suppl, 1S - 17S
{In vitro antibacterial activity of meropenem, a new carbapenem: European data}; Debbia EA et al.; Meropenem is a new DHP-I stable carbapenem with a very promising microbiological, pharmacokinetic and clinical profile . The antibacterial activity of this new agent has been assessed in vitro against 8741 aerobic and 854 anaerobic strains reflecting current incidence and epidemiology in Italy, France, Germany, Spain, Switzerland and United Kingdom . Comparator agents were imipenem, ceftriaxone, vancomycin, ciprofloxacin gentamicin and amikacin . The results of this study show that meropenem has a spectrum of antibacterial activity which embraces the vast majority of clinically significant Gram-positive and Gram-negative aerobes and anaerobes . This is due in part to excellent stability to chromosomal or plasmid mediated beta-lactamases including those which hydrolyse current cephalosporins . Data from the Italian study identified meropenem as the most potent agent against all Enterobacteriaceae, with the exception of Proteus species with were most susceptible to ciprofloxacin . Moreover, meropenem was 10 times more active than the other drugs against Haemophilus and Neisseria and was active against all the anaerobic strains . Conversely, staphylococci and enterococci were more susceptible to imipenem . Overall, these European data showed that meropenem was the most powerful drug against Enterobacteriaceae and it also was the most effective drug tested against the Italian and French Pseudomonas aeruginosa strains . Meropenem was less effective than imipenem or vancomycin against Enterococcus stains but had similar activity to imipen against anaerobes . Based on this microbiological profile, the use of meropenem is appropriate in the empirical treatment of serious infections, including those caused by multiple pathogens.

Pediatr Emerg Care, 1995 Oct, 11(5), 280 - 4
Bacteremia and meningitis among infants with urinary tract infections; Bachur R et al.; A retrospective analysis of 354 patients < or = 2 years of age with urinary tract infections (UTIs) was performed to characterize patients with bacteremia or meningitis and to identify any objective predictors of these complications . Thirty-three patients with bacteremia were identified . Blood culture isolates included Escherichia coli (25), Staphylococcus aureus (4), enterococcus (1), group B Streptococcus (2), and Enterobacter (1) . Besides one patient with group B Streptococcus bacteremia at 1.5 months of age, all bacteremias after one month of age were with E . coli . Bacteremia was limited to those < 6 months old and inversely related to age (R = 0.24, P = 0.0008) . Grouped by age, the incidence of bacteremia was 21% for 0 < or = 1 month, 13% for 1.1-2.0 months, 4% for 2.1-3.0 months, and 8% for 3.1-6.0 months . Mean white blood cell count, initial temperature, initial serum bicarbonate, and erythrocyte sedimentation rate were not statistically significant between bacteremic (B) and nonbacteremic (NB) patients . Statistically significant differences were noted for percentage of bands (6.2% {NB} vs . 12.3% {B} P < 0.001), total band count (1048 {NB} vs . 2252 {B} P < 0.001), and band-neutrophil ratio (0.16 {NB} vs . 0.36 {B} P = 0.01); however, no practical value for any of these measures would reliably discriminate between bacteremic and nonbacteremic patients . Four patients, all neonates, had meningitis; too few patients with meningitis were identified for analysis . In summary, bacteremia with UTIs was observed to be inversely related to age and limited to patients less than six months of age . No objective parameters were identified to distinguish patients with bacteremia at the time of presentation.

J Clin Microbiol, 1995 Oct, 33(10), 2601 - 6
Molecular identification of bacteria by fluorescence-based PCR-single-strand conformation polymorphism analysis of the 16S rRNA gene; Widjojoatmodjo MN et al.; PCR-single-strand conformation polymorphism (PCR-SSCP) analysis is a rapid and convenient technique for the detection of mutations and allelic variants . We have adapted this technique for the identification of bacteria by PCR with fluorescein-labeled primers chosen from the conserved regions of the 16S rRNA gene flanking a variable region . The PCR product was denatured, separated on a nondenaturing gel, and detected by an automated DNA sequencer . The mobility of the single-stranded DNA is sequence dependent and allows the identification of a broad panel of bacteria . A single nucleotide difference in the amplified region was sufficient to obtain different PCR-SSCP patterns . The simultaneous amplification of multiple polymorphic regions by multiplex PCR with subsequent multiplex SSCP increased the discriminatory power of PCR-SSCP . A broad range of gram-negative and gram-positive bacteria were tested by PCR-SSCP, including, e.g., Escherichia coli, Enterobacter spp., Klebsiella spp., Haemophilus spp., Neisseria spp., Staphylococcus spp, Streptococcus spp., Enterococcus spp., and Bacillus spp . In total, a panel of 178 strains of bacteria representing 51 species in 21 genera was examined . Although a limited number of strains from each species were tested, the strains tested gave species-specific patterns, with only one exception: Shigella species were indistinguishable from E . coli . PCR is a sensitive technique; as few as 10 CFU of E . coli was sufficient to produce PCR-SSCP patterns suitable for identification . The whole fluorescence PCR-SSCP procedure takes approximately 8 h for the detection and identification of low numbers of bacteria.2+ fluorescence PCR-SSCP seems to be a promising method for the differentiation of a broad range of pathogens found in usually sterile clinical sites, such as blood and cerebrospinal fluid.

J Clin Microbiol, 1995 Oct, 33(10), 2525 - 9
Controlled clinical comparison of Isolator and BACTEC 9240 Aerobic/F resin bottle for detection of bloodstream infections; Pohlman JK et al.; A controlled clinical comparison was carried out with the BACTEC 9240 Aerobic/F resin bottle and the Isolator system with adult patients suspected of having bloodstream infections . A total of 10,500 paired specimens were collected, of which 1,122 from 520 patients were positive . There were 68 false-positive BACTEC bottles; 259 positive cultures that were excluded from analysis because the bottle, the Isolator, or both failed to meet the minimum volume criterion of 8 ml of blood; and 207 positive cultures that were excluded because the isolates were found to be clinically insignificant or of indeterminate clinical significance on the basis of patient assessment . A total of 656 positive cultures from 258 patients formed the basis of the analysis . Significantly more Staphylococcus aureus isolates (P = 0.03), Staphylococcus epidermidis isolates (P = 0.03), members of the family Enterobacteriaceae (P = 0.03), and Pseudomonas aeruginosa isolates (P = 0.04) were recovered from the resin bottle, and there was no category of organism that was recovered significantly more frequently from the Isolator system . With patients receiving antibiotics at the time of blood culture, S . aureus, S . epidermidis, and gram-negative bacilli were recovered significantly more frequently from the resin bottle . No significant differences between systems were found with cultures from patients not receiving antibiotics at the time of blood culture . Only 12 clinically significant organisms were recovered from the bottle on terminal subcultures, and only 1 of these had not been previously isolated from another blood culture set (10 of the 12) or from the companion Isolator (1 of 12) . The Aerobic/F resin bottle continuously monitored in the BACTEC 9240 instrument proved to be superior to the Isolator in overall yield of organisms causing bloodstream infection in adults and required less technician time for specimen processing and examination than the Isolator system.

J Hosp Infect, 1995 Oct, 31(2), 99 - 104
Pyrolysis mass spectrometry of cephalosporin-resistant Enterobacter cloacae; Ahmet Z et al.; Thirteen clinical and four environmental isolates of third-generation cephalosporin-resistant Enterobacter cloacae (CREC) together with single isolates from the hands of a nurse and from a blood gas analyser were associated with two clusters of nosocomial infection . With an unrelated CREC isolate they had been typed by serotype, biotype, ribotype and phage-type and were examined by pyrolysis mass spectrometry (PYMS) as described here . PYMS data yielded two clusters, major and minor . All except one isolate in the major cluster corresponded to type group identity (serotype 07, biotype 62, ribotype D) which had caused neonatal sepsis and colonization . Multivariate analysis showed a homogeneous group consisting of this strain plus two outliers . The minor cluster included four different strains, one of which, serotype 03, biotype 62, ribotype C had caused excoriation of the buttocks and colonization.

J Hosp Infect, 1995 Oct, 31(2), 89 - 97
Decreased transmission of Enterobacteriaceae with extended-spectrum beta-lactamases in an intensive care unit by nursing reorganization; Soulier A et al.; In our gastrointestinal surgical intensive care unit (SICU), the large number of patients with multiple enterostomies enhances the risk of nosocomial transmission of gut extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLE) by health care workers . A control study performed in our SICU from June-August 1992 showed an ESBLE gut colonization rate of 70% . To reduce this rate, nursing procedures were intensified or modified, particularly handwashing, single-use equipment and waste control . To test the efficiency of these procedures, 64 patients hospitalized for more than two days from September 1992-March 1993 were screened for gut acquisition of ESBLE . Rectal samples were taken within 48 h after admission and then weekly . After nursing reorganization, the ESBLE colonization rate dropped significantly to 40% (P < 0.001) . Twenty patients (31.7%) acquired a gut ESBLE, after a mean of 24.3 +/- 13.7 days . Each patient was colonized with one, two or three ESBLE (Klebsiella pneumoniae, Escherichia coli and Enterobacter aerogenes) . Baseline characteristics of the 20 colonized and 39 non-colonized patients showed no significant difference (Student's t-test, P > 0.05) . The nursing workload, estimated as a omega index, was greater in the colonized group (P < 0.001) . These findings show that strict observance of nursing procedures can significantly reduce ESBLE acquisition in a high-risk surgical unit.

J Clin Pathol, 1995 Oct, 48(10), 929 - 32
Lethal synergy between toxins of staphylococci and enterobacteria: implications for sudden infant death syndrome; Sayers NM et al.; AIM--To test the hypothesis that lethal synergy occurs between toxin preparations of nasopharyngeal staphylococci and enterobacteria from sudden infant death syndrome (SIDS) victims and matched healthy infants . METHODS--SIDS and matched healthy babies were studied if both staphylococcal and enterobacterial strains were isolated from the nasopharynx . The lethality of toxin preparations from each bacterial isolate (separately and combined) was assessed over a range of dilutions using the chick embryo assay system . RESULTS--Staphylococci and enterobacteria were isolated together from the nasopharynx of seven SIDS babies but from only one normal healthy infant . Enterobacterial toxins were lethal at high dilutions . Staphylococcal toxins were less toxic . Simultaneous testing in the chick assay of staphylococcal and enterobacterial toxins, from each baby, at non-lethal concentrations enhanced lethality levels by 177 to 1011% compared with lethality expected by an additive effect alone . CONCLUSIONS--Synergy occurs between the toxins of nasopharyngeal staphylococci and enterobacteria . This combination of strains is more likely to occur in the nasopharynx of SIDS victims than that of healthy infants.

Biosci Biotechnol Biochem, 1995 Oct, 59(10), 1938 - 43
Enzymatic synthesis of L-tryptophan by Enterobacter aerogenes tryptophanase highly expressed in Escherichia coli, and some properties of the purified enzyme; Kawasaki K et al.; We constructed two plasmids that have a strong tac promoter and a structural gene for tryptophanase of Enterobacter aerogenes SM-18 (pKT901EA) or Escherichia coli K-12 (pKT951EC) . The tryptophanase activity of E . coli JM109 transformed with pKT901EA (JM109/pKT901EA) was inducible with isopropyl-beta-D-thiogalactopyranoside, and 3.6 times higher than that of E . aerogenes SM-18 . Cells of JM109/pKT901EA induced for tryptophanase synthesized L-tryptophan from indole, ammonia, and pyruvate more efficiently than E . aerogenes SM-18 . Although JM109/pKT951EC expressed a similar level of tryptophanase activity to that of JM109/pKT901EA, the synthesis of L-tryptophan by the cells of JM109/pKT951EC did not proceed well compared with JM109/pKT901EA . Tryptophanases from E . aerogenes and E . coli K-12 were purified, and their properties were investigated . The purified E . aerogenes tryptophanase showed higher stability against heat inactivation than E . coli tryptophanase.

J Appl Bacteriol, 1995 Oct, 79(4), 360 - 7
Efficiency of different enrichment and isolation procedures for the detection of Salmonella serotypes in edible offal; Arroyo G et al.; Rapid detection systems for Salmonella in foodstuffs are currently being developed . However, existing standards still call for application of traditional methods employing pre-enrichment followed by selective enrichment and isolation . The efficacy of various methods was tested using 264 chicken and lamb organ meats . Pre-enrichment was carried out in Tryptone Soy Broth (TSB) and enrichment in Tetrathionate Brilliant Green Broth (TTB) at 37 degrees C, Selenite Broth with Brilliant Green and Sulphapyridine at 37 degrees C and 43 degrees C, and Rappaport-Vassiliadis Broth (RV 10) at 42 degrees C . The isolation media were Brilliant Green Agar (BGA), Deoxycholate Citrate Agar, Hektoen Enteric Agar (HEA) and Salmonella-Shigella Agar . Enrichment in RV/42 degrees C followed by isolation on BGA as recommended by ISO standard no . 6579 and enrichment in TTB/37 degrees C followed by isolation in HEA, no longer recommended by that standard, produced the best results . Low percentages of positive samples and difficulties in detecting Salmonella are the result of interference by competing organisms (Enterobacteriaceae) and the number of salmonellas present after enrichment . A total of 528 samples (TSB, eggs, lamb liver and chicken liver) were inoculated with Salm . enteritidis, Salm . kapemba and Salm . virchow, and the preceding experiment was repeated . All the TSB and egg samples tested positive, but the percentage of positive samples from the lamb and chicken liver was only 81-92% . Recovery of the salmonellas did not depend upon the method employed or the serotype inoculated but instead on interference by competing flora and the numbers of Salmonella present in the samples.

Epidemiol Infect, 1995 Oct, 115(2), 269 - 77
PCR-based characterization of Yersinia enterocolitica: comparison with biotyping and serotyping; Odinot PT et al.; PCR-based DNA fingerprinting was used to characterize 48 clinical isolates of Yersinia enterocolitica . The samples were examined by random amplified polymorphic DNA (RAPD-PCR) and inter-repeat PCR (IR-PCR) . IR-PCR with two enterobacterial repetitive intergenic consensus primers resulted in patterns which were poorly discriminated; 2 of 11 arbitrary primers (RAPD-PCR) provided sufficient discriminatory power . In comparisons with serotyping and biotyping, RAPD-fingerprinting was the most discriminatory technique and may therefore be a valuable epidemiological tool for the study of Y . enterocolitica infections.

Microbiology, 1995 Oct, 141 ( Pt 10), 2535 - 42
A 17 kDa outer-membrane protein (Omp4) from Serratia marcescens confers partial resistance to bacteriocin 28b when expressed in Escherichia coli; Guasch JF et al.; A cosmid-based genomic library of Serratia marcescens N28b was introduced into Escherichia coli and clones were screened for a bacteriocin 28b insensitive phenotype . One clone was found that showed partial resistance to bacteriocin 28b . By using Tn5tac1 insertions it was shown that this phenotype was due to the expression in E . coli of an outer-membrane protein of 17 kDa (Omp4) . The DNA region defined by insertion mutagenesis was sequenced and found to contain an ORF of 515 bp . The deduced amino acid sequence has 172 residues with a theoretical molecular mass of 18.4 kDa . The protein contains an N-terminal signal sequence of 24 amino acid residues and, when compared to other enterobacterial outer-membrane proteins, most closely resembles a family of small outer-membrane proteins of Enterobacteriaceae whose known functions appear to be related with virulence . Immunoblotting experiments showed that Omp4 is present in 15 biotypes of S . marcescens . The bacteriocin 28b resistance phenotype conferred on E . coli by Omp4 appears to be pleiotropic since overexpression of the Omp4-encoding gene leads to a decrease in the amount of OmpA, OmpF and/or OmpC; OmpA and OmpF are the receptors for bacteriocin 28b in E . coli.

J Bacteriol, 1995 Oct, 177(19), 5539 - 46
Genetic analysis of the dTDP-rhamnose biosynthesis region of the Escherichia coli VW187 (O7:K1) rfb gene cluster: identification of functional homologs of rfbB and rfbA in the rff cluster and correct location of the rffE gene; Marolda CL et al.; The O-repeating unit of the Escherichia coli O7-specific lipopolysaccharide is made of galactose, mannose, rhamnose, 4-acetamido-4,6-dideoxyglucose, and N-acetyglucosamine . We have recently characterized the genes involved in the biosynthesis of the sugar precursor GDP-mannose occurring in the E . coli O7:K1 strain VW187 (C . L . Marolda and M . A . Valvano, J . Bacteriol . 175:148-158, 1993) . In the present study, we identified and sequenced the rfbBDAC genes encoding the enzymes for the biosynthesis of another precursor, dTDP-rhamnose . These genes are localized on the upstream end of the rfbEcO7 region, and they are strongly conserved compared with similar genes found in various enteric and nonenteric bacteria . Upstream of rfbB we identified a DNA segment containing the rfb promoter and a highly conserved untranslated leader sequence also present in the promoter regions of other surface polysaccharide gene clusters . Also, we have determined that rfbB and rfbA have homologs, rffG (o355) and rffH (o292), respectively, located on the rff cluster, which is involved in the synthesis of enterobacterial common antigen . We provide biochemical evidence that rffG and rffH encode dTDP-glucose dehydratase and glucose-1-phosphate thymidylyltransferase activities, respectively, and we also show that rffG complemented the rfbB defect in the O7+ cosmid pJHCV32 . We also demonstrate that rffG is distinct from rffE and map the rffE gene to the second gene of the rff cluster.

Int J Syst Bacteriol, 1995 Oct, 45(4), 848 - 51
Wigglesworthia gen . nov . and Wigglesworthia glossinidia sp . nov., taxa consisting of the mycetocyte-associated, primary endosymbionts of tsetse flies; Aksoy S; The primary endosymbionts (P-endosymbionts) of tsetse flies (Diptera: Glossinidae) are harbored inside specialized cells (mycetocytes) in the anterior region of the gut, and these specialized cells form a white, U-shaped organelle called mycetome . The P-endosymbionts of five tsetse fly species belonging to the Glossinidae have been characterized morphologically, and their 16S ribosomal DNA sequences have been determined for phylogenetic analysis . These organisms were found to belong to a distinct lineage related to the family Enterobacteriaceae in the gamma subdivision of Proteobacteria, which includes the secondary endosymbionts of various insects and Escherichia coli . These bacteria are also related to the P-endosymbionts of aphids, Buchnera aphidicola . Signature sequences in the 16S ribosomal DNA and genomic organizational differences which distinguish the tsetse fly P-endosymbionts from members of the Enterobacteriaceae and from the genus Buchnera are described in this paper . I propose that the P-endosymbionts of tsetse flies should be classified in a new genus, the genus Wigglesworthia, and a new species, Wigglesworthia glossinidia . The P-endosymbiont found in the mycetocytes of Glossina morsitans morsitans is designated the type strain of this species.

Arch Microbiol, 1995 Oct, 164(4), 280 - 9
Lipopolysaccharide of Rhodospirillum salinarum 40: structural studies on the core and lipid A region; Rau H et al.; The structural elucidation of lipid A of the cell wall lipopolysaccharide (LPS) of Rhodospirillum salinarum 40 by chemical methods and laser desorption mass spectrometry revealed the presence of a mixed lipid A composed of three different 1,4'bisphosphorylated beta (1 --> 6)-linked backbone hexosaminyl-hexosamine disaccharides, i.e . those composed of GlcN --> GlcN, 2,3-diamino-2,3-dideoxy-D-Glc-(DAG --> DAG, and DAG --> GlcN . Lipid A of R . salinarum contained preferentially 3-OH-18:0 and 3-OH-14:0 as amide-linked and cis delta 11-18:1 and c19:0 as ester-linked fatty acids . The mass spectra of the liberated acyl-oxyacyl residues proved the concomitant presence of 3-O-(cis delta 11-18:1)-18:0 and 3-O-(c19:0)-14:0 as the predominating diesters in this mixed lipid A . The glycosidically linked and the ester-linked phosphate groups of the backbone disaccharide were neither substituted by ethanolamine, phosphorylethanolamine, nor by 4-amino-4-deoxy-L-arabinose, in contrast to most of the enterobacterial lipid As . In the core oligosaccharide fraction, a HexA (1 --> 4)HexA(1 --> 5)Kdo-trisaccharide was identified by methylation analysis . The terminal HexA (hexuronic acid) is possibly 4-OMe-GalA, a component described here as an LPS constituent for the first time . LPS of R . salinarum showed a lethality in C57BL/10 ScSN (LPS-responder)-mice) of an order of 10(-1)-10(-2) of that reported for Salmonella abortus equi LPS, and it was also capable of inducing TNF alpha and IL6 in macrophages of C57BL/10ScSN mice.

Schweiz Med Wochenschr, 1995 Sep 9, 125(36), 1684 - 6
{Epidemiology of antibiotic resistance: implications for empirical treatment in intensive care}; Wolff M; The adequacy of initial antibiotic therapy is an important prognostic factor in severe infections . Concerning nosocomial infections, the selection of appropriate empirical therapy should take into account the incidence of offending pathogens within a specific unit . The changing trends in the hospital's microbial resistance patterns should be known to the physicians . The bacteria involved and the susceptibility testing vary widely among institutions and among countries . Many risk factors for acquisition of resistant pathogens have been identified . The duration of stay in hospital, previous colonization, and antibiotic treatment are the most frequently cited risk factors . When P . aeruginosa is suspected, an ureido-penicillin/aminoglycoside combination is usually effective . However, in some units with high levels of resistance, the beta-lactam should be ceftazidime or imipenem . When enterobacteria are suspected, a third generation cephalosporin, alone or in combination with an amino-glycoside or a broad spectrum penicillin associated with a beta-lactamase inhibitor is appropriate . Early nosocomial staphylococcal infections are treated with nafcillin or oxacillin, alone or in combination with an aminoglycoside . In units with a high rate of MRSA, the initial antibiotic therapy should include a glycopeptide.

J Antimicrob Chemother, 1995 Sep, 36(3), 513 - 9
Effect of pO2 and pH on synergy of tazobactam and beta-lactam antibiotics against beta-lactamase producing Enterobacteriaceae; Konig C et al.; Synergy between tazobactam and ceftriaxone or piperacillin against beta-lactamase producing Enterobacteriaceae was not influenced by the presence or absence of oxygen . For most strains synergy was excellent at neutral pH but reduced in acidic conditions . Low pH increased 50% of the MICs up to or beyond the sensitivity breakpoint.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1995 Sep, 11(5), 327 - 9
{An investigation into antibiotic resistance and plasmid pattern of Enterobacter cloacae in burn infection}; Li Y et al.; In view of a high positive isolation rate and resistance to antibiotics of Enterobacter cloacae in our department, 32 strains of E . cloacae, which were isolated from blood and infected wounds of burned patients from June through November 1990, were randomly selected to determine their susceptibility to 21 antibiotics and their plasmid patterns . It was found that 29 of 32 strains were resistant to at least nine antibiotics, while the other three strains were relatively sensitive . 27 of 32 strains of E . cloacae were tested for plasmid, and among them, three strains (relatively sensitive to antibiotics) contained no plasmid . The plasmid patterns of the other 24 isolates varied with strains, but all of them had a 80 kb plasmid . The 80 kb plasmid was obviously related to the high isolation rate and high resistance to antibiotics of E . cloacae isolated in our department.

Mol Microbiol, 1995 Sep, 17(6), 1167 - 75
A cell-surface polysaccharide that facilitates rapid population migration by differentiated swarm cells of Proteus mirabilis; Gygi D et al.; Swarming by Proteus mirabilis is characterized by cycles of rapid population migration across surfaces, following differentiation of typical vegetative rods into long, hyperflagellated, virulent swarm cells . A swarm-defective TnphoA insertion mutant was isolated that was not defective in cell motility, differentiation or control of the migration cycle, but was specifically impaired in the ability to undergo surface translocation as a multicellular mass . The mutation, previously shown to compromise urinary tract virulence, was located within a 1112 bp gene that restored normal swarming of the mutant when expressed in trans . The gene encoded a 40.6 kDa protein that is related to putative sugar transferases required for lipopolysaccharide (LPS) core modification in Shigella and Salmonella . The immediately distal open reading frame encoded a protein that is related to dehydrogenases involved in the synthesis of LPS O-side-chains, enterobacterial common antigen and extracellular polysaccharide (PS) . Gel electrophoresis and electron microscopy showed that the mutant still made LPS but it had lost the ability to assemble a surface (capsular) PS, which gas-liquid chromatography and mass spectrometry indicated to be an acidic type II molecule rich in galacturonic acid and galactosamine . We suggest that this surface PS facilitates translocation of differentiated cell populations by reducing surface friction.

FEMS Immunol Med Microbiol, 1995 Sep, 12(1), 47 - 50
Salmonella enterotoxin (stn) gene is prevalent among strains of Salmonella enterica, but not among Salmonella bongori and other Enterobacteriaceae; Prager R et al.; All strains and serovars of Salmonella enterica such as serovar Typhimurium, Enteritidis, Dublin, Typhi, etc . were found to carry the Salmonella enterotoxin determinant stn as far as examined in PCR and hybridization studies . However, using MDCK cells for testing the toxicity of the strains under investigation, only a limited number of stn positive strains revealed phenotypically the Salmonella enterotoxin Stn . In contrast to S . enterica, other Enterobacteriaceae including Salmonella bongori were found neither genotypically nor phenotypically Stn toxin positive.

Mikrobiol Z, 1995 Sep-Oct, 57(5), 3 - 15
{Gram-negative bacteria contaminating the process of producing lysine}; Vasilevskaia IA et al.; The authors have isolated Gram-negative bacteria of the Enterobacteriaceae family from the culture liquid of industrial fermenters with low yield of lysine . Most of them possessed the characters typical of Klebsiella pneumoniae and Escherichia coli, the rest were identified as the representatives of genera Proteus, Providencia, Enterobacter, Hafnia . Strains of Klebsiella pneumoniae, E.coli, Proteus rettgeri manifested lysine-decarboxylase activity . The capacity of some strains to destruct lysine synthesized by the target culture in the process of fermentation with formation of cadaverin was experimentally proved and confirmed under production conditions . Technological water is the source of distribution of gram-negative bacteria (first of all Klebsiella) in lysine production.

Microb Pathog, 1995 Sep, 19(3), 139 - 57
Binding specificity for four monoclonal antibodies recognizing terminal Gal alpha 1-->4Gal residues in Haemophilus influenzae lipopolysaccharide; Borrelli S et al.; Four murine monoclonal antibodies (MAbs) reactive with the outer-core region of the lipopolysaccharide (LPS) from Haemophilus influenzae were generated after immunization with azide-killed H . influenzae RM.7004 AH1-2 and their epitope specificities studied . The monoclonal antibodies: MAHI 6 (IgM), MAHI 5 (IgG2a), MAHI 8 (IgG3), and MAHI 11 (IgG2b) bound to synthetic glycoconjugates or glycolipids with terminal galabiosyl (Gal alpha 1-->4Gal beta 1-) or globotriaosyl (Gal alpha 1-->4Gal beta 1 1-->4GLc) residues as evaluated in enzyme immunoassays (EIA) . Glycoconjugates or glycolipids with internally placed galabiose elements were not active, indicating selectively of the MAbs for recognition of the epitope . Nine LPSs from H . influenzae inhibited the binding of the four MAbs . The presence of the galabiosyl disaccharide element in these nine LPSs was evidence by the binding of 125I-labeled Shiga toxin isolated from the bacterium Shigella dysenteriae type 1, reported to have as receptor the Gal alpha 1-->4Gal beta disaccharide (Lindberg et al., J Biol Chem, 1987, 262: 1779-85) . Structural studies of these H . influenzae LPSs were also in accord with the presence of the galabiosyl disaccharide, in addition 1H-NMR spectroscopy showed the presence of O-acetyl groups in the RM.7004 AH1-2 LPS . However, differential binding specificities of the MAbs to modified RM.7004 AH1-2 LPSs were observed . MAHI 6 and MAHI 11 bound equally well to LPS, polysaccharides obtained after mild acidic treatment, and dephosphorylated LPS samples as shown in inhibition EIA . In contrast, both dephosphorylated LPS samples and polysaccharides were poorer inhibitors of the binding of MAHI 5 and MAHI 8 to native RM.7004 AH1-2 LPS . Neither the de-O-acylated nor the de-O,N-acylated LPSs were effective inhibitors of any of the four MAbs . These results suggest that the MAbs recognition involves Gal alpha 1-->4Gal and O-acetyl and other saccharide residue(s) from the oligosaccharide moiety of the LPS . The epitopes are also expressed and accessible to recognition in clinical isolates coming from different sources of Neisseria spp., Haemophilus spp., and Moraxella catarrhalis, but not in Bordetella spp., Aeromonas spp . or Enterobacteriaceae as evaluated by whole-bacteria EIA and colony-dot-immunoblotting.

Chemotherapy, 1995 Sep-Oct, 41(5), 345 - 52
Piperacillin tazobactam compared with co-amoxiclav, ampicillin plus sulbactam and timentin against beta-lactamase-producing clinical isolates of Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca; Traub WH et al.; A total of 266 enterobacterial isolates (Escherichia coli = 190, Klebsiella pneumoniae = 49, K . oxytoca = 27) were tested for susceptibility (Bauer-Kirby agar disk diffusion test and agar dilution procedure) to ampicillin, ampicillin in 10 micrograms/ml of sulbactam, amoxicillin in 4 micrograms/ml of clavulanic acid, piperacillin, piperacillin plus tazobactam (8:1 ratio), ticarcillin and timentin (ticarcillin in 4 micrograms/ml of clavulanic acid) . Discrepant results between the two methods of susceptibility testing were categorized as follows: category I = very major {minimal inhibitory concentration (MIC) = resistant, disk diffusion = susceptible} category II = major (MIC = susceptible, disk diffusion = resistant), category III = minor (MIC = intermediate susceptibility, disk diffusion = susceptible), category IV = slight (MIC = resistant, disk diffusion = intermediate), category V = minimal (MIC = susceptible, disk diffusion = intermediate) and category VI = negligible (MIC = intermediate, disk diffusion = resistant) . The antibiotics, or combinations with beta-lactamase inhibitors, yielded the following discrepant results: ampicillin (II = 2, V = 1 and VI = 3), co-amoxiclav (I = 5, III = 25, IV = 1 and V = 3), ampicillin plus sulbactam (I = 5, II = 3, III = 1, V = 19 and VI = 1), piperacillin (II = 15, III = 1, V = 15 and VI = 85), piperacillin plus tazobactam (III = 16, IV = 2, V = 1 and VI = 5) and timentin (I = 2, III = 48 and IV = 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Am J Clin Pathol, 1995 Sep, 104(3), 279 - 82
Evaluation of routine anaerobic blood cultures in the BacT/Alert blood culture system; Bannister ER et al.; To evaluate the use of routine anaerobic blood cultures with the BacT/Alert system, results of 12,289 blood culture sets collected from adults over a 9-month period were reviewed . Of the sets included in the study, 1,306 (10.6%) from 808 patients grew 1 or more organisms . Anaerobes were present in 39 sets from 38 patients . Of the positive sets, both bottles were positive in 60.7% of cases, the aerobic bottle only in 23.7%, and the anaerobic bottle only in 15.6% . When only the 254 patients who had 2 or more positive sets were considered, both bottles were positive in 71.5% of cases, the aerobic bottle only in 20.7%, and the anaerobic only in 7.8% . In this subset of patients gram-positive bacilli, gram-negative bacilli other than Enterobacteriaceae, and yeasts grew significantly more frequently in aerobic bottle . No organisms preferred the anaerobic bottle . These data support the selective use of the BacT/Alert anaerobic blood culture bottle in patients at risk for anaerobic bacteremia.

J Bacteriol, 1995 Sep, 177(17), 5108 - 15
Identification of a global repressor gene, rsmA, of Erwinia carotovora subsp . carotovora that controls extracellular enzymes, N-(3-oxohexanoyl)-L-homoserine lactone, and pathogenicity in soft-rotting Erwinia spp; Cui Y et al.; The production of extracellular enzymes such as pectate lyase (Pel), polygalacturonase (Peh), cellulase (Cel), and protease (Prt) is activated by the cell density (quorum)-sensing signal, N-(3-oxohexanoyl)-L-homoserine lactone (HSL); plant signals; and aep genes during postexponential growth of Erwinia carotovora subsp . carotovora 71 . Studies with mutants of E . carotovora subsp . carotovora 71 derepressed in exoenzyme production led to the identification of a negative regulator gene, rsmA (rsm, repressor of secondary metabolites) . Nucleotide sequencing, transcript assays, and protein analysis established that a 183-bp open reading frame encodes the 6.8-kDa RsmA . rsmA has extensive homology with the csrA gene of Escherichia coli, which specifies a negative regulator of carbon storage . Moreover, the suppression of glycogen synthesis in E . coli by rsmA indicates that the Erwinia gene is functionally similar to csrA . Southern hybridizations revealed the presence of rsmA homologs in soft-rotting and non-soft-rotting Erwinia spp . and in other enterobacteria such as Enterobacter aerogenes, E . coli, Salmonella typhimurium, Shigella flexneri, Serratia marcescens, and Yersinia pseudotuberculosis . rsmA suppresses production of Pel, Peh, Cel, and Prt, plant pathogenicity, and synthesis of HSL in E . carotovora subsp . atroseptica, E . carotovora subsp . betavasculorum, E . carotovora subsp . carotovora, and E . chrysanthemi . In the E . carotovora subsp . carotovora 71, rsmA reduces the levels of transcripts of hslI, a luxI homolog required for HSL biosynthesis . This specific effect and the previous finding that HSL is required for extracellular enzyme production and pathogenicity in soft-rotting Erwinia spp . support the hypothesis that rsmA controls these traits by modulating the levels of the cell density (quorum)-sensing signal.

Am J Respir Crit Care Med, 1995 Sep, 152(3), 1028 - 33
Pattern of tracheal colonization during mechanical ventilation; de Latorre FJ et al.; The relationship between gastric (GC) and tracheal (TC) colonization and the development of ventilator-associated pneumonia (VAP) remains controversial . TC, GC, and pharyngeal (PC) colonization were studied serially in 80 patients with mechanical ventilation (MV) to ascertain the routes and onset of TC . Simultaneous sample from pharynx, stomach, and trachea were obtained throughout the MV period . Quantitative cultures were performed . Seventy-two patients (90%) had TC at some time during MV . Only 19 patients presented TC after PC or GC by the same microorganisms . Indigenous gram-negative and gram-positive microorganisms colonized mainly the trachea from the start of or during MV without previous PC or GC (p < 0.05) . Pseudomonas were the microorganisms causing TC principally during MV without previous PC or GC (p < 0.005) . Enterobacteria produced TC without a preferential route . Of the 12 patients who developed VAP, the microorganisms responsible had already colonized the trachea in 10 patients . Only 10 of the 21 microorganisms isolated in VAP had previously colonized the pharynx or stomach . In summary, although some microorganisms have preferential routes for producing TC, the microorganisms isolated frequently change during MV . TC precedes VAP in most patients, but only a minority develop a VAP; therefore, together with TC other factors must be involved in VAP development.

Lett Appl Microbiol, 1995 Sep, 21(3), 160 - 3
Evaluation of the BBL Crystal Enteric/Nonfermenter kit for the identification of water-derived environmental Enterobacteriaceae; Micklewright IJ et al.; The Crystal Enteric/Nonfermenter (E/NF) identification kit (Becton Dickinson Microbiology Systems, USA) was evaluated using water-derived bacterial isolates and results compared to those obtained by the API 20E system (BioMerieux, UK) . Both the E/NF and 20E systems correctly identified 93% of the Enterobacteriaceae reference cultures . Both systems agreed in the identification of 64.9% of environmental isolates . The E/NF system gave a positive identification to 88.0% of isolates and the 20E to 79.5% of isolates . The principal tests which gave differing reactions between the two systems were arginine dihydrolase, lysine decarboxylase, urease and citrate utilization.

Infect Immun, 1995 Sep, 63(9), 3683 - 92
The tetrasaccharide L-alpha-D-heptose1-->2-L-alpha-D-heptose1--> 3-L-alpha-D-heptose1-->(3-deoxy-D-manno-octulosonic acid) and phosphate in lipid A define the conserved epitope in Haemophilus lipopolysaccharides recognized by a monoclonal antibody; Borrelli S et al.; A murine monoclonal antibody, MAHI 3 (immunoglobulin G2b), that is broadly reactive with Haemophilus influenzae lipopolysaccharides (LPSs) but nonreactive with all enterobacterial LPSs tested was generated by fusing mouse myeloma cells with spleen cells of BALB/c mice immunized with azide-killed H . influenzae RM.7004 . MAHI 3 bound to all H . influenzae, all other human Haemophilus spp., all Bordetella pertussis and Bordetella parapertussis, and all Aeromonas spp . tested but not to any Neisseria or Moraxella catarrhalis strains, as determined by enzyme immunoassay, colony dot immunoblotting, and immunoblotting . In an inhibition enzyme immunoassay, MAHI 3 reacted with all 45 H . influenzae LPSs tested but not with the LPS from the rough mutant I69 Rd-/b+, which has only 3-deoxy-D-manno-octulosonic acid (P) {Kdo(P)} and lipid A . The antibody was not inhibited by H . influenzae lipid A or lipid-free polysaccharide isolated after mild acid hydrolysis . Only native LPSs show positive inhibitory activity, indicating that part of lipid A is involved in the binding of MAHI 3 . From the results, it is indicated that the structural element recognized by MAHI 3 is Hep alpha 1-->2Hep alpha 1-->3Hep alpha 1-->Kdo together with part of lipid A, including the phosphate.

J Hosp Infect, 1995 Sep, 31(1), 61 - 6
DNA fingerprinting of Pseudomonas aeruginosa serotype O11 by enterobacterial repetitive intergenic consensus-polymerase chain reaction and pulsed-field gel electrophoresis; Lau YJ et al.; We report the use of pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based polymerase chain reaction (PCR) to characterize clinical isolates of Pseudomonas aeruginosa serotype O11 collected from an incident of hospital-acquired infection . Both typing techniques differentiated 20 different strain types among seven epidemiologically related isolates and 22 epidemiologically unrelated isolates . There was complete concordance between these two techniques . Our results indicate that the ERIC-based PCR technique represents a rapid and simple means for typing P . aeruginosa serotype O11 with a level of discrimination equivalent to that of PFGE.

Microbiology, 1995 Sep, 141 ( Pt 9), 2157 - 64
Distribution of the ardA family of antirestriction genes on conjugative plasmids; Chilley PM et al.; The ardA gene of I1 plasmid ColIb-P9 was previously shown to alleviate DNA restriction by type I enzymes and to promote conjugative transmission of the unmodified plasmid to a restricting host . To clarify the ecological role of ardA, its distribution was determined on plasmids from 23 incompatibility groups using hybridization to the coding sequence as an assay . Hybridizing sequences, shown by nucleotide sequencing to have at least 60% identity with ardA, were detected on plasmids belonging to the I complex (IncB, I1 and K), the F complex (IncFV) and the IncN group . The ardA homologues were found to specify an antirestriction phenotype which was enhanced by genetic depression of the plasmid transfer system . ardA loci map in plasmid leading regions but show no consistent association with a particular type of origin-of-transfer or a leading region gene of the ssb (single-stranded DNA-binding protein), psiB (plasmid SOS inhibition) and hok (host killing) families . It may be significant that ardA+ plasmids are authentic enterobacterial plasmids and that type I restriction systems are associated historically with members of the Enterobacteriaceae.

J Clin Microbiol, 1995 Sep, 33(9), 2372 - 6
Characterization of Hafnia alvei by biochemical tests, random amplified polymorphic DNA PCR, and partial sequencing of 16S rRNA gene; Ridell J et al.; Hafnia alvei strains which possess the attachment-effacement gene (eaeA) may have clinical importance as new diarrhea-causing pathogens and should therefore be differentiated from other H . alvei strains . We characterized diarrheal H . alvei strains, which were positive in the PCR test for the eaeA gene, using biochemical tests not routinely used for identification of members of the family Enterobacteriaceae, and compared them with eaeA-negative strains isolated from different clinical and nonclinical sources to find characteristics useful for identification . Random amplified polymorphic DNA (RAPD)-PCR and partial sequencing of the 16S rRNA gene were utilized to study the genetic diversity of the isolates . The eaeA-positive strains were found to have many characteristic biochemical properties . Negative reactions in the 2-ketogluconate and histidine assimilation tests and a positive reaction in the 3-hydroxybenzoate assimilation test may be useful in routine diagnostics . Nearly identical RAPD-PCR profiles and identical 353-bp fragments of the 16S rRNA genes indicated little genetic diversity among the eaeA-positive strains . The low level of homology (92%) in the partial 16S rRNA genes of eaeA-positive and -negative H . alvei strains raises questions about the taxonomic positioning of eaeA-positive H . alvei.

Pharm Acta Helv, 1995 Sep, 70(3), 227 - 32
Microbiological quality of pharmaceutical raw materials; de la Rosa MC et al.; A total of 115 samples of pharmaceutical raw materials (excipients) were analysed: 36 lactose, 27 talc, 19 corn starch, 18 arabic gum, 8 gelatin, 3 gelatinized starch, 3 cellulose and one tragacanth gum . 69.9% of the samples showed less than 10(2) bacteria/g (mean = 23.2 cfu/g) and 95.2% less than 10(2) fungi/g (mean = 4.92 cfu/g) . Arabic and tragacanth gum were the most contaminated products by bacteria and fungi, respectively . Pregelatinized starch, cellulose and lactose were the least contaminated excipients . In none of the samples Escherichia coli or Salmonella-Shigella were detected; however, strains of Enterobacter, Serratia and Proteus were isolated from 10 samples of 5 different excipients . Only 5 samples did not comply with the microbiological standards as established by the European Pharmacopoeia and USP.

Carbohydr Res, 1995 Aug 25, 273(2), 157 - 70
Determination by NMR spectroscopy of the structure and conformational features of the enterobacterial common antigen isolated from Escherichia coli; Bruix M et al.; Complete 1H and 13C spectrum of a polysaccharide isolated from Escherichia coli, which is the major component of the enterobacterial common antigen, has been analyzed through two-dimensional nuclear magnetic resonance spectroscopy . In addition, distance constraints from NOESY and ROESY experiments have been combined with molecular dynamic simulations to determine its major conformation in water solution . Data resulting from both free dynamic simulations and restrained dynamic simulations have been compared with experimental data and discussed.

JAMA, 1995 Aug 23-30, 274(8), 639 - 44
The prevalence of nosocomial infection in intensive care units in Europe . Results of the European Prevalence of Infection in Intensive Care (EPIC) Study . EPIC International Advisory Committee; Vincent JL et al.; OBJECTIVE--To determine the prevalence of intensive care unit (ICU)-acquired infections and the risk factors for these infections, identify the predominant infecting organisms, and evaluate the relationship between ICU-acquired infection and mortality . DESIGN--A 1-day point-prevalence study . SETTING--Intensive care units in 17 countries in Western Europe, excluding coronary care units and pediatric and special care infant units . PATIENTS--All patients (> 10 years of age) occupying an ICU bed over a 24-hour period . A total of 1417 ICUs provided 10 038 patient case reports . MAIN OUTCOME MEASURES--Rates of ICU-acquired infection, prescription of antimicrobials, resistance patterns of microbiological isolates, and potential risk factors for ICU-acquired infection and death . RESULTS--A total of 4501 patients (44.8%) were infected, and 2064 (20.6%) had ICU-acquired infection . Pneumonia (46.9%), lower respiratory tract infection (17.8%), urinary tract infection (17.6%), and bloodstream infection (12%) were the most frequent types of ICU infection reported . Most frequently reported micro-organisms were Enterobacteriaceae (34.4%), Staphylococcus aureus (30.1%;{60% resistant to methicillin}, Pseudomonas aeruginosa (28.7%), coagulase-negative staphylococci (19.1%), and fungi (17.1%) . Seven risk factors for ICU-acquired infection were identified: increasing length of ICU stay (> 48 hours), mechanical ventilation, diagnosis of trauma, central venous, pulmonary artery, and urinary catheterization, and stress ulcer prophylaxis . ICU-acquired pneumonia (odds ratio {OR}, 1.91; 95% confidence interval{Cl}, 1.6 to 2.29), clinical sepsis (OR, 3.50; 95% Cl, 1.71 to 7.18), and bloodstream infection (OR, 1.73; 95% Cl, 1.25 to 2.41) increased the risk of ICU death . CONCLUSIONS--ICU-acquired infection is common and often associated with microbiological isolates of resistant organisms . The potential effects on outcome emphasize the importance of specific measures for infection control in critically ill patients.

Cancer Res, 1995 Aug 15, 55(16), 3558 - 63
Regressions and cures of melanoma xenografts following treatment with monoclonal antibody beta-lactamase conjugates in combination with anticancer prodrugs; Kerr DE et al.; Cephalosporin doxorubicin (C-Dox) and 7-(4-carboxybutanamido)-cephalosporin mustard (CCM) are prodrugs that are catalytically converted by Enterobacter cloacae beta-lactamase (bL) to the active anticancer agents doxorubicin and phenylenediamine mustard, respectively . Both prodrugs were less cytotoxic to the 3677 human melanoma line than their respective drugs and were activated in an immunologically specific manner by 96.5-bL, a mAb-bL conjugate that binds to 3677 cell surface antigens . Similar results were obtained using the CCM prodrug on SK-MEL 28 human melanoma cells . Experiments in mice with established s.c . 3677 tumors demonstrated that although no tumors were cured in mice receiving the 96.5-bL/C-Dox combination, the activities were greater than those obtained from systemic doxorubicin treatment or from administration of the nonbinding conjugate P1.17-bL in combination with C-Dox . In contrast, when CCM was used as a prodrug, cures of established 3677 tumors were obtained in 80% of the 96.5-bL treated animals . This combination was also able to induce regressions of large 3677 tumor masses (800 mm3) without any apparent toxic side effects . We conclude that 96.5-bL in combination with C-Dox or CCM has greater antitumor activity than systemic treatment with the corresponding drugs and that CCM is a more effective prodrug than C-Dox for treating human 3677 melanoma xenografts.

Cryobiology, 1995 Aug, 32(4), 358 - 65
Isolation of ice-nucleating active bacteria from the freeze-tolerant frog, Rana sylvatica; Lee MR et al.; Ice-nucleating active (INA) bacteria were isolated from the gut of field-collected freeze-tolerant wood frogs (Rana sylvatica) collected in winter . Thirteen strains of Pseudomonas fluorescens, four strains of Pseudomonas putida, and two strains of Enterobacter agglomerans had ice-nucleating activity . Each of the INA pseudomonad strains was psychrophilic . P . putida strains were differentiated from P . fluorescens strains by gelatinase, lecithinase, and lipase production . The maximum nucleation temperatures (Tmax) of aqueous suspensions (10(9) bacteria/ml) of the four INA P . putida strains ranged from -1.6 to -3.0 degrees C, which places this INA species among the most potent known biological nucleators . Ingestion of INA P . putida isolated from R . sylvatica by another freeze-tolerant frog . Pseudacris crucifer, decreased the capacity of this frog to supercool and remain unfrozen at -2 degrees C . This is the first report of INA bacteria isolated from a vertebrate, and suggests that, as part of the gut flora in some posthibernation freeze-tolerant wood frogs, these bacteria may play a role in enhancing winter survival by promoting ice nucleation at high subzero temperatures (ca . -2 degrees C).

FEMS Microbiol Lett, 1995 Aug 1, 130(2-3), 287 - 92
Vibrio parahaemolyticus O serotypes from O1 to O13 all produce R-type lipopolysaccharide: SDS-PAGE and compositional sugar analysis; Iguchi T et al.; The molecular architecture of lipopolysaccharide (LPS) isolated from all O serotypes of Vibrio parahaemolyticus was investigated . In gel chromatography on a Sephadex G-50 column, the degraded polysaccharide fraction prepared from each serotype LPS by mild acid hydrolysis yielded only core oligosaccharide (Frc II) and monosaccharide (Frc III) fractions, but no fraction (Frc I) corresponding to O polysaccharide chain consisting of polymeric repeating oligosaccharide units . Compositional sugar analysis of Frc II and III suggested that the sugar chain of LPS of all the serotypes of V . parahaemolyticus consisted of at most ten monosaccharides . Sodium dodecylsulfate-polyacrylamide gel electrophoresis of the LPS resulted in no doublet ladder band similar to that observed for S-type enterobacterial LPS . These results are compatible with the interpretation that V . parahaemolyticus O serotypes from O1 to O13 all produce R-type LPS, despite the morphologically smooth appearance, demonstrated virulence and serological O-specificity.

Kansenshogaku Zasshi, 1995 Aug, 69(8), 924 - 7
Inhibitory action of metabolites of Pseudomonas aeruginosa against gram-negative bacteria; Li Z et al.; Fifty clinical isolates of Pseudomonas aeruginosa were tested for inhibition of growth of clinical isolates of Escherichia coli, Salmonella infantis, Klebsiella pneumoniae and other Gram-negative bacteria in the authors' laboratory . Pseudomonas aeruginosa was strongly active against both E . coli and Enterobacter cloacae, with 89.4% and 94.7% inhibition respectively, but weakly active against S . infantis, K . pneumoniae and Proteus mirabilis with 56.3%, 48.8% and 23.8% inhibition, respectively . The pigmented strains were found to have stronger antimicrobial activity than the unpigmented strains . Pyocyanin, the major metabolite of Pseudomonas aeruginosa, has been shown to inhibit Escherichia coli, Proteus spp . and other Gram-negative bacteria, by research with a few strains of P . aeruginosa and a single inhibited strain . However, little attempt has been made to determine the inhibitory action of many strains of P . aeruginosa against a large number of clinical isolates such as Escherichia spp., Klebsiella spp., and Salmonella spp., up to now . For this reason, in this study we examined 50 randomly selected clinical isolates of P . aeruginosa for inhibition of growth of a wide range of Gram-negative bacteria, including 30 strains of E . coli, 30 of K . pneumoniae, 30 of S . infantis, 6 of Enterobacter cloacae and 9 of Proteus mirabilis.

J Appl Bacteriol, 1995 Aug, 79(2), 141 - 8
The relationship between ecophysiology, indigenous microflora and growth of Listeria monocytogenes in grass silage; Donald AS et al.; The combined effect of the physical and chemical parameters (oxygen tension, pH and dry matter) influencing Listeria monocytogenes growth and survival in silage were simultaneously studied in a model in vitro system . Ensiled grass was exposed to a range of low oxygen concentrations, 0-5% v/v, and their effect was recorded with respect to acidification and microbial population dynamics of the epiphytic microflora, i.e . lactic acid bacteria, enterobacteria, yeasts, moulds and L . monocytogenes in grasses pre-inoculated with the latter . Listeria monocytogenes survival depended on the establishment of a fine balance between the physico-chemical and microbiological characteristics, i.e . oxygen tension, dry matter, pH, grass and microbiological quality . In all grasses ensiled, an oxygen concentration of 1.0% or greater sustained L . monocytogenes growth, below this level growth was shown to be principally dependent on the rate and quality of the fermentation . In most grasses 0.5% oxygen prolonged survival, whereas 0.1% and 0% oxygen caused L . monocytogenes to die off . In very poor quality grass with a restricted fermentation L . monocytogenes survival was prolonged even under anaerobic conditions.

Microbiology, 1995 Aug, 141 ( Pt 8), 1909 - 20
Multidrug resistance in Klebsiella pneumoniae: a novel gene, ramA, confers a multidrug resistance phenotype in Escherichia coli; George AM et al.; Spontaneous multidrug-resistant (Mdr) mutants of Klebsiella pneumoniae strain ECL8 arose at a frequency of 2.2 x 10(-8) and showed increased resistance to a range of unrelated antibiotics, including chloramphenicol, tetracycline, nalidixic acid, ampicillin, norfloxacin, trimethoprim and puromycin . A chromosomal fragment from one such mutant was cloned, and found to confer an Mdr phenotype on Escherichia coli K12 cells that was essentially identical to that of the K . pneumoniae mutant . Almost complete loss of the OmpF porin in the E . coli transformant, and of the corresponding porin in the K . pneumoniae mutant, was observed . The presence of the Mdr mutation in K . pneumoniae or the cloned K . pneumoniae ramA (resistance antibiotic multiple) locus in E . coli also resulted in active efflux of tetracycline, and increased active efflux of chloramphenicol . After transformation of a ramA plasmid into E . coli, expression of chloramphenicol resistance occurred later than expression of resistance to tetracycline, puromycin, trimethoprim and nalidixic acid . The ramA gene was localized and sequenced . It encodes a putative positive transcriptional activator that is weakly related to the E . coli MarA and SoxS proteins . A ramA gene was also found to be present in an Enterobacter cloacae fragment that has previously been shown to confer an Mdr phenotype, and it appears that ramA, rather than the romA gene identified in that study, is responsible for multidrug resistance . The ramA gene from the wild-type K . pneumoniae was identical to that of the mutant strain and also conferred an Mdr phenotype on E . coli, indicating that the mutation responsible for Mdr in K . pneumoniae had not been cloned.

Anasthesiol Intensivmed Notfallmed Schmerzther, 1995 Aug, 30(5), 315 - 9
{Fournier's gangrene . Experiences and changes in the disease picture since its initial description}; Thum P et al.; Fournier's disease mostly occurs in immunosuppressed men in the 5th to 7th decade of life . Bacteria from the urogenital or colorectal tract lead to a rapid spreading soft tissue infection . Painful scrotal or perineal swelling and a black spot as a sign of beginning necrosis are guiding symptoms . Involved bacteria are grampositive cocci, enterobacteriaceae and anaerobes . Main principles of therapy are immediate radical debridement and broad spectrum antibiotics . Sepsis renders the prognosis more infaust.

J Bacteriol, 1995 Aug, 177(15), 4488 - 500
Expression of genes kdsA and kdsB involved in 3-deoxy-D-manno-octulosonic acid metabolism and biosynthesis of enterobacterial lipopolysaccharide is growth phase regulated primarily at the transcriptional level in Escherichia coli K-12; Strohmaier H et al.; We have cloned and sequenced a cluster of six open reading frames containing gene kdsA from Escherichia coli K-12 . The gene encodes 3-deoxy-D-manno-octulosonate 8-phosphate synthetase (KDO-8-phosphate synthetase), which catalyzes formation of 3-deoxy-D-manno-octulosonic acid (KDO), an essential component of enterobacterial lipopolysaccharide . We have also identified two other genes, hemA and prfA, at the beginning of the cluster . Deletion analysis shows that kdsA, the terminal gene of this putative operon, is transcribed from its own promoter located within the cluster rather than from two promoters preceding this group of six open reading frames . Northern (RNA) blot analysis as well as lacZ operon fusion experiments reveal that the expression of gene kdsA occurs maximally in the early log phase and falls to a low level in the late log and stationary phases . Hence, this gene is subjected to growth phase-dependent regulation at the transcriptional level . Similarly, we show that expression of gene kdsB, which codes for the CTP:CMP-3-deoxy-D-manno-octulosonate cytidyltransferase (CMP-KDO-synthetase), is also growth regulated . This enzyme catalyzes the activation of KDO via formation of CMP-KDO, which is necessary for the incorporation of KDO into lipid A . We have identified the promoter of gene kdsB, whose expression is growth regulated in the same way as that of kdsA . Despite the fact that transcription of genes kdsA and kdsB is shut off as cells enter stationary phase, KDO-8-phosphate synthetase as well as CMP-KDO-synthetase activities are still present at various levels during stationary-phase growth of an E . coli K-12 culture.

Genetics, 1995 Aug, 140(4), 1407 - 12
Synonymous substitution rates in enterobacteria; Eyre-Walker A et al.; It has been shown previously that the synonymous substitution rate between Escherichia coli and Salmonella typhimurium is lower in highly than in weakly expressed genes, and it has been suggested that this is due to stronger selection for translational efficiency in highly expressed genes as reflected in their greater codon usage bias . This hypothesis is tested here by comparing the substitution rate in codon families with different patterns of synonymous codon use . It is shown that the decline in the substitution rate across expression levels is as great for codon families that do not appear to be subject to selection for translational efficiency as for those that are . This implies that selection on translational efficiency is not responsible for the decline in the substitution rate across genes . It is argued that the most likely explanation for this decline is a decrease in the mutation rate . It is also shown that a simple evolutionary model in which synonymous codon use is determined by a balance between mutation, selection for an optimal codon, and genetic drift predicts that selection should have little effect on the substitution rate in the present case.

Appl Environ Microbiol, 1995 Aug, 61(8), 2950 - 7
Characterization of rhizosphere colonization by luminescent Enterobacter cloacae at the population and single-cell levels; Rattray EA et al.; A bioluminescence marker system was used to characterized colonization of the rhizosphere by a bacterial inoculum, both in terms of population activity and at the single-cell level . Plasmid pQF70/44, which contains luxAB genes under the control of a strong constitutive phage promoter, was introduced into the rhizobacterium and model biocontrol agent Enterobacter cloacae . Light output from the lux-modified strain was detected by luminometry of samples from growing cultures of E . cloacae and from inoculated soil and wheat root samples . The minimum detection limits for fully active cells under optimum conditions were 90 and 445 cells g-1 for liquid culture and soil, respectively . The metabolic activities of the lux-marked population of E . cloacae, characterized by luminometry, contrasted in rhizosphere and nonrhizosphere soil . Cells in the rhizosphere were active, and there was a linear relationship between light output and cell concentration . The activity of cells in nonrhizosphere coil could not be detected unless the soil was supplied with substrate . Novel use of a charge-coupled device is reported for the spatial characterization of rhizosphere colonization by E . cloacae (pQF70/44) at the single-cell and population levels . Used macroscopically, the charge-coupled device identified differences in colonization due to competition from indigenous soil organisms . The lux-marked bacterium was able to colonize all depths of roots in the absence of competition but was restricted tot he spermosphere in the presence of competition (nonsterile soil).(ABSTRACT TRUNCATED AT 250 WORDS)

Appl Environ Microbiol, 1995 Aug, 61(8), 2898 - 904
Enterobacterial repetitive intergenic consensus sequences and the PCR to generate fingerprints of genomic DNAs from Vibrio cholerae O1, O139, and non-O1 strains; Rivera IG et al.; Enterobacterial repetitive intergenic consensus (ERIC) sequence polymorphism was studied in Vibrio Cholerae strains isolated before and after the cholera epidemic in Brazil (in 1991), along with epidemic strains from Peru, Mexico, and India, by PCR . A total of 17 fingerprint patterns (FPs) were detected in the V . cholerae strains examined; 96.7% of the toxigenic V . cholerae O1 strains and 100% of the O139 serogroup strains were found to belong to the same FP group comprising four fragments (FP1) . The nontoxigenic V . cholerae O1 also yielded four fragments but constituted a different FP group (FP2) . A total of 15 different patterns were observed among the V . cholerae non-O1 strains . Two patterns were observed most frequently for V . cholerae non-01 strains, 25% of which have FP3, with five fragments, and 16.7% of which have FP4, with two fragments . Three fragments, 1.75, 0.79, and 0.5 kb, were found to be common to both toxigenic and nontoxigenic V . cholerae O1 strains as well as to group FP3, containing V . cholerae non-O1 strains . Two fragments of group FP3, 1.3 and 1.0 kb, were present in FP1 and FP2 respectively . The 0.5-kb fragment was common to all strains and serogroups of V . cholerae analyzed . It is concluded from the results of this study, based on DNA FPs of environmental isolates, that it is possible to detect an emerging virulent strain in a cholera-endemic region . ERIC-PCR constitutes a powerful tool for determination of the virulence potential of V . cholerae O1 strains isolated in surveillance programs and for molecular epidemiological investigations.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1790 - 6
Cloning and characterization of a 3-N-aminoglycoside acetyltransferase gene, aac(3)-Ib, from Pseudomonas aeruginosa; Schwocho LR et al.; A novel gene encoding an aminoglycoside 3-N-acetyltransferase, which confers resistance to gentamicin, astromicin, and sisomicin, was cloned from Pseudomonas aeruginosa Stone 130 . Its sequence was determined and found to show considerable similarity to an aac(3)-I gene previously cloned from R plasmids from Enterobacter, Pseudomonas, and Serratia spp . We have designated the genes from the R plasmids and this work aac(3)-Ia and aac(3)-Ib, respectively . The two aac(3)-I genes share 74% nucleotide identity, and their deduced protein products are 88% similar . These data suggest that the genes derive from a common ancestor . Homology between the flanking sequences of both aac(3)-I genes and other resistance determinants known to reside in integron environments was also observed . Intragenic probes specific for either aac(3)-Ia or aac(3)-Ib were used in hybridization studies with a series of gentamicin-, astromicin-, and sisomicin-resistant clinical isolates . Of 59 clinical isolates tested, no isolates hybridized with both probes, 30 (51%) hybridized with the aac(3)-Ia probe, 12 (20%) hybridized with the aac(3)-Ib probe, and 17 (29%) did not hybridize with either probe . These data suggest the existence of at least one other aac(3)-I gene.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1764 - 71
Bactericidal killing activities of cefepime, ceftazidime, cefotaxime, and ceftriaxone against Staphylococcus aureus and beta-lactamase-producing strains of Enterobacter aerogenes and Klebsiella pneumoniae in an in vitro infection model; Palmer SM et al.; Cefepime (CP) is a new injectable cephalosporin with a broad spectrum of activity and stability against common chromosomally and plasmid-mediated beta-lactamases . The bactericidal activities of CP, ceftazidime (CZ), cefotaxime (CTX), and ceftriaxone (CAX) against reference and clinical strains of Staphylococcus aureus, an isogenic pair of Enterobacter aerogenes strains (wild type and a CZ-resistant derepressed mutant), and a Klebsiella pneumoniae isolate possessing a TEM-10 beta-lactamase were investigated in a two-compartment pharmacodynamic in vitro infection model which simulates human pharmacokinetics . An inoculum of approximately 10(6) CFU/ml was used in all model experiments . Antibiotics were administered to simulate the following regimens: CP at 2 g every 12 h (q12h), CZ at 2 g q8h, CTX at 2 g q8h, and CAX at 2 g q24h . Human albumin was added during experiments with CAX and staphylococci to simulate protein binding . Samples were removed at multiple time points over a 48-h period to determine the inoculum size for time-kill curves . Development of resistance was detected by inoculating samples obtained at 0, 24, and 48 h onto antibiotic-containing agar plates . The time to 99.9% killing was used to compare drug regimens . Against staphylococci, the time to bacterial eradication was significantly delayed with CAX-albumin . All regimens had similar activities against the wild-type Enterobacter strain; however, regrowth was noted with CZ, CTX, and CAX against the CZ-resistant strain . There were no differences between the CP, CTX, and CAX regimens against K . pneumoniae . Of interest, no regrowth of any organism was noted with CP . These data indicate that CP has activity against S.aureus and CZ-resistant gram-negative bacilli.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1711 - 6
In vitro pharmacodynamics of piperacillin, piperacillin-tazobactam, and ciprofloxacin alone and in combination against Staphylococcus aureus, Klebsiella pneumoniae, Enterobacter cloacae, and Pseudomonas aeruginosa; Hyatt JM et al.; The time-kill curve methodology was used to determine the pharmacodynamics of piperacillin, ciprofloxacin, piperacillin-tazobactam and the combinations piperacillin-ciprofloxacin and ciprofloxacin-piperacillin-tazobactam . Kill curve studies were performed for piperacillin, ciprofloxacin, and piperacillin-tazobactam at concentrations of 0.25 to 50 times the MICs for 13 strains of bacteria: four Pseudomonas aeruginosa, three Enterobacter cloacae, three Klebsiella pneumoniae, and three Staphylococcus aureus isolates (tazobactam concentrations of 0.5, 4, and 12 micrograms/ml) . By using a sigmoid Emax model and nonlinear least squares regression, the 50% lethal concentrations and the maximum lethal rates of each agent were determined for each bacterial strain . For piperacillin-ciprofloxacin and ciprofloxacin-piperacillin-tazobactam, kill curve studies were performed with concentrations obtained by the fractional maximal effect method (R . C . Li, J . J . Schentag, and D . E . Nix, Antimicrob . Agents Chemother . 37:523-531, 1993) and from individual 50% lethal concentrations and maximum lethal rates . Ciprofloxacin-piperacillin-tazobactam was evaluated only against the four P . aeruginosa strains . Interactions between piperacillin and ciprofloxacin were generally additive . At physiologically relevant concentrations of piperacillin and ciprofloxacin, ciprofloxacin had the highest rates of killing against K . pneumoniae . Piperacillin-tazobactam (12 micrograms/ml) had the highest rate of killing against E . cloacae . Piperacillin-ciprofloxacin with relatively higher ciprofloxacin concentrations had the greatest killing rates against S . aureus . This combination had significantly higher killing rates than piperacillin (P < 0.002) . For all the bacterial strains tested, killing rates by ciprofloxacin were significantly higher than those by piperacillin-tazobactam (4 and 12 micrograms/ml had significantly higher killing rates than piperacillin alone (P < 0.02 and P < 0.004, respectively) . The effect of the combination of piperacillin-ciprofloxacin, in which piperacillin concentrations were relatively higher, was not statistically different from that of piperacillin alone (p > or = 0.71) . The combination of ciprofloxacin-piperacillin-tazobactam achieved greater killing than other combinations or monotherapies against P . aeruginosa . The reduction in the initial inoculum was 1 to 4 logs greater with ciprofloxacin-piperacillin-tazobactam at 4 and 12 micrograms/ml than with any other agent or combination of agents . On the basis of the additive effects prevalently demonstrated in the in vitro study, the combinations of piperacillin-ciprofloxacin and piperacillin-tazobactam are rational therapeutic options . Greater killing of P . aeruginosa was demonstrated with ciprofloxacin-piperacillin--tazobactam . Since treatment failure of P . aeruginosa pneumonia is a significant problem, clinical studies are warranted.

N Engl J Med, 1995 Jul 20, 333(3), 147 - 54
Postoperative infections traced to contamination of an intravenous anesthetic, propofol; Bennett SN et al.; BACKGROUND . Between June 1990 and February 1993, the Centers for Disease Control and Prevention conducted investigations at seven hospitals because of unusual outbreaks of bloodstream infections, surgical-site infections, and acute febrile episodes after surgical procedures . METHODS . We conducted case-control or cohort studies, or both, to identify risk factors . A case patient was defined as any patient who had an organism-specific infection or acute febrile episode after a surgical procedure during the study period in that hospital . The investigations also included reviews of procedures, cultures, and microbiologic studies of infecting, contaminating, and colonizing strains . RESULTS . Sixty-two case patients were identified, 49 (79 percent) of whom underwent surgery during an epidemic period . Postoperative complications were more frequent during the epidemic period than before it . Only exposure to propofol, a lipid-based anesthetic agent, was significantly associated with the postoperative complications at all seven hospitals . In six of the outbreaks, an etiologic agent (Staphylococcus aureus, Candida albicans, Moraxella osloensis, Enterobacter agglomerans, or Serratia marcescens) was identified, and the same strains were isolated from the case patients . Although cultures of unopened containers of propofol were negative, at two hospitals cultures of propofol from syringes currently in use were positive . At one hospital, the recovered organism was identical to the organism isolated from the case patients . Interviews with and observation of anesthesiology personnel documented a wide variety of lapses in aseptic techniques . CONCLUSIONS . With the increasing use of lipid-based medications, which support rapid bacterial growth at room temperature, strict aseptic techniques are essential during the handling of these agents to prevent extrinsic contamination and dangerous infectious complications.

Biochem J, 1995 Jul 15, 309 ( Pt 2), 431 - 6
Breakdown of the stereospecificity of DD-peptidases and beta-lactamases with thiolester substrates; Damblon C et al.; With peptide analogues of their natural substrates (the glycopeptide units of nascent peptidoglycan), the DD-peptidases exhibit a strict preference for D-Ala-D-Xaa C-termini . Gly is tolerated as the C-terminal residue, but with a significantly decreased activity . These enzymes were also known to hydrolyse various ester and thiolester analogues of their natural substrates . Some thiolesters with a C-terminal leaving group that exhibited L stereochemistry were significantly hydrolysed by some of the enzymes, particularly the Actinomadura R39 DD-peptidase, but the strict specificity for a D residue in the penultimate position was fully retained . These esters and thiolesters also behave as substrates for beta-lactamases . In this case, thiolesters exhibiting L stereochemistry in the ultimate position could also be hydrolysed, mainly by the class-C and class-D enzymes . However, more surprisingly, the class-C Enterobacter cloacae P99 beta-lactamase also hydrolysed thiolesters containing an L residue in the penultimate position, sometimes with a higher efficiency than the D isomer.

J Immunol, 1995 Jul 15, 155(2), 877 - 85
Inhibition of TNF-triggering activity of lipopolysaccharide by a proteinaceous factor from normal mouse liver extract; Satoh M et al.; Recent studies have revealed that animals have evolved a wide range of protective systems against the deleterious effects of LPS, but the molecular mechanisms in the barrier functions of liver against enterobacterial LPS, particularly in mammals, are poorly understood . In this study, we extracted a soluble fraction from the liver of normal mice (normal liver extract, NLE) and examined its effect on biologic activities of LPS . Preincubation of NLE and LPS suppressed serum-dependent TNF induction (TNF-triggering activity) of LPS; the effect was dose-dependent and overcome by increasing LPS concentration, but treatment of macrophages with NLE showed no effect . Separation by ultrafiltration and protease sensitivity demonstrated that the factor(s) in NLE was a protein(s) . We tentatively called this liver LPS-inactivating factor (LLIF) . LPS inactivation by LLIF was temperature-dependent and required the coexistence of divalent cations . LLIF also suppressed a synthetic lipid A analogue, ONO-4007 . Pretreatment of LPS with serum rendered LPS refractory to the action of LLIF . However, LLIF was unable to inhibit limulus amebocyte lysate activation by LPS . Direct interaction of LLIF and lipid A was evident by the method of {1-14C}ONO-4007 binding to solid-phase LLIF, but treatment of {1-14C}ONO-4007 with LLIF generated no degradative products . These results suggest that LLIF probably interacts with the lipid A portion of LPS and interferes with the association of LPS and LBP (LPS-binding protein) in serum, and that LLIF may be one of the protective molecules in liver against the gastrointestine-derived LPS.

FEMS Microbiol Lett, 1995 Jul 15, 130(1), 63 - 8
Effects of mutations and deletions on expression of the Enterobacter cloacae ompX gene; de Kort G et al.; The Enterobacter cloacae outer membrane protein OmpX is involved in resistance to beta-lactams, and possesses virulence characteristics . To gain more insight into the genetic elements that are important for OmpX expression, several mutations were introduced at, and immediately upstream of, the N-terminus of the OmpX coding sequence . These mutations enabled us to delete the 5' untranslated region and the signal peptide coding sequence . The former led to decreased ompX expression, indicating an unexpected and hitherto unexplained role for this region . Deletion of the signal peptide coding sequence blocked transport across the cytoplasmic membrane, indicating that translocation of OmpX across the cytoplasmic membrane is mediated by the general secretory pathway.

Rev Latinoam Microbiol, 1995 Jul-Sep, 37(3), 217 - 25
{Plasmid size determination using 3 methods}; Darini AL et al.; Analysis of bacterial plasmid profiles has been shown to be very important in epidemiological studies, especially those involving outbreaks of nosocomial infections . The molecular weight size of unknown plasmids is determined by comparing their band pattern obtained in agarose gel electrophoresis with those obtained with plasmids that have been used as molecular weight or size standards . In this study, we determined the size of plasmids present in clinical samples of Enterobacter cloacae comparing their electrophoresis mobility with seven plasmids of known size, using three different mathematical methods . For plasmids with molecular weight ranging from 2 kb to 100 kb . The most accurate determinations were obtained by power-function . Analyses using the exponential variables obtained with these plasmids were accurate for two types of plasmids, those with size ranging from 50 kb to 100 kb and those with size ranging from 2 kb to 30 kb . We also observed discrepancies among the methodologies described, including one used by a computer software designed for calculating the size of plasmids DNA.

J Investig Allergol Clin Immunol, 1995 Jul-Aug, 5(4), 221 - 7
Chemotaxis of alveolar macrophages and neutrophils in response to microbial products derived from organic dust; Milanowski J et al.; Mechanisms of chemotaxis of alveolar macrophages (AMs) and neutrophils (PMNs) in response to microbial products derived from organic dust were studied using the blindwell chemotaxis chamber technique . Seven different known etiological agents causing respiratory symptoms were used for experiments: cell extract and endotoxin from Pantoea agglomerans (synonyms: Erwinia herbicola, Enterobacter agglomerans), cell extracts from Thermoactinomyces vulgaris and Aspergillus fumigatus, protease from Bacillus thermoproteolyticus rokko and two preparations of glucans . These agents were evaluated for their ability to direct attraction of alveolar macrophages and neutrophils and stimulation of alveolar macrophages to release chemotactic factors for other alveolar macrophages and neutrophils . The microbial products were able to attract both alveolar macrophages and neutrophils directly in a dose-dependent manner, and the exposure of cultured alveolar macrophages to most agents stimulated chemotactic activity for for alveolar macrophages and neutrophils . The generation and release of this activity by alveolar macrophages may provide a mechanism for the initiation and amplification of inflammatory reactions in the lung after inhalation of organic dust . Results of these in vitro studies may be relevant to the pathogenesis of alveolitis in organic dust-induced lung diseases.

Rom J Intern Med, 1995 Jul-Dec, 33(3-4), 227 - 35
Sensitivity to augmentin and cephalosporines of some bacterial strains isolated from hospitalized patients; Debeleac L et al.; The study allowed the determination of the degree of antibacterial efficiency of three antimicrobial agents belonging to the betalactamine family namely cefuroxime (IInd generation), ceftazidime (IIIrd generation) and augmentin . Likewise the relationship bacterial species-antibiotic could be established . It was found that the pathogenic staphylococcus strains were very sensitive to cefuroxime (92.1%) and equally sensitive to ceftazidime and augmentin (61.0%) . The enterococci were 100% sensitive to augmentin and 100% resistant to both cephalosporines . The enterobacteriaceae presented a higher percentage of sensitive strains to cephalosporines than to augmentin 89.6% of the E . coli strains were sensitive to ceftazidime, 77.9% to cefuroxime and 27.3% to augmentin . Klebsiella was sensitive in 68.2%, 45.14% and 13.6% of the cases to ceftazidime, cefuroxime and respectively augmentin . Proteus presented 64.7% strains sensitive to ceftazidime, 35.3% sensitive to cefuroxime and 29.3% sensitive to augmentin . All the enterobacter strains proved resistant to the three antibiotics studied.

J Antimicrob Chemother, 1995 Jul, 36 Suppl A, 85 - 97
A randomised comparison of meropenem with cefotaxime or ceftriaxone for the treatment of bacterial meningitis in adults . Meropenem Meningitis Study Group; Schmutzhard E et al.; Third-generation cephalosporins are presently the agents of choice for the empirical antimicrobial therapy of bacterial meningitis . However, a number of factors associated with these agents, namely the development of resistance by pneumococci, limited activity against some Enterobacteriaceae and Pseudomonas spp., and the possible adverse effects of their bacteriolytic mode of action, indicate that newer classes of antimicrobial agents be evaluated for the treatment of bacterial meningitis . Meropenem is a carbapenem antibiotic which is highly active against the major bacterial pathogens causing meningitis, and penetrates well into the cerebrospinal fluid . Two prospective randomised studies in 56 adult bacterial meningitis patients have compared meropenem 40 mg/kg 8-hourly, up to a maximum of 6 g/day (n = 28) with cephalosporin treatment, i.e . cefotaxime (n = 17) or ceftriaxone (n = 11) . Patients were assessed by neurological examination, Glasgow Coma Score and Herson-Todd score . Clinical cure was observed in all 23 evaluable patients treated with meropenem (100%) and with 17 of the 22 evaluable cephalosporin-treated patients (77%) . All pre-treatment isolates were eradicated except one isolate of Staphylococcus aureus in a cefotaxime-treated patient . Neurological sequelae were noted in three meropenem and four cephalosporin-treated patients . No patients in either treatment group experienced seizures after the start of therapy . This was despite the fact that a patient in each group had experienced seizures before therapy, several had underlying CNS disorders, and that doses of 6 g/day of meropenem were given . Hearing impairment was recorded in 11 meropenem and nine cephalosporin treated patients . Three patients in the meropenem group and one in the cephalosporin group died during treatment for reasons unrelated to study therapy . Overall, the results of this study indicate that meropenem is an effective and well-tolerated antibiotic for the treatment of bacterial meningitis in adults.

J Antimicrob Chemother, 1995 Jul, 36 Suppl A, 19 - 34
Extended-spectrum plasmid-mediated beta-lactamases; Sirot D; Extended-spectrum beta-lactamases (ESBLs) are mutant enzymes which derive from TEM or SHV (class A) enzymes . They confer variable levels of resistance to cefotaxime, ceftazidime and other broad-spectrum cephalosporins and to monobactams such as aztreonam but have no detectable activity against cephamycins and carbapenems . Recently, new plasmid-mediated ESBLs, not derived from TEM or SHV enzymes but related to cephalosporinases of Enterobacteriaceae (class C enzymes), that confer resistance to all cephalosporins including cephamycins, have been reported . However, to date there have been no reported outbreaks due to strains producing transferable cephalosporinases . Klebsiella pneumoniae is the species in which the ESBL enzymes have been most commonly reported around the world . Most of the clinical isolates that produce TEM- or SHV-derived ESBL, come from hospitalised patients and have frequently caused nosocomial outbreaks . Care should be taken in the selection of a beta-lactam for the treatment of infections because the presence of an ESBL does not prevent other mechanisms of resistance, such as decreased permeability, from emerging . Broad-spectrum cephalosporins including cefepime and cefpirome are hydrolysed by ESBL . However, low level resistance to cefotaxime, ceftriaxone, cefepime and aztreonam does occur in some strains producing certain TEM-derived ESBL . It remains to be seen, therefore, whether such isolates are clinically susceptible to these drugs . The combination of a third-generation cephalosporin and a beta-lactamase inhibitor such as sulbactam could be of interest against some strains producing certain ESBLs . Among the 7-alpha-methoxy cephalosporins, cefotetan and latamoxef are the most active . However, cephamycins should be used with caution to treat infections caused by ESBL-producing K . pneumoniae because of the relative ease with which clinical strains decrease the expression of outer membrane proteins . The most active beta-lactams are the carbapenems, imipenem and meropenem, which are highly resistant to hydrolysis by TEM and SHV related beta-lactamases . Meropenem is intrinsically the more active agent, with MICs (0.03-0.12 mg/L) generally lower than those of imipenem (0.06-0.5 mg/L) and appears stable to all the beta-lactamases belonging to class A or C, including those with an extended-spectrum against third-generation cephalosporins.

J Antimicrob Chemother, 1995 Jul, 36 Suppl A, 121 - 33
Treatment of acute bacterial exacerbations of chronic obstructive pulmonary disease in hospitalised patients--a comparison of meropenem and imipenem/cilastatin . COPD Study Group; Hamacher J et al.; Meropenem and imipenem/cilastatin were compared in an open, randomised prospective multicentre study in the treatment of acute exacerbations of severe chronic obstructive pulmonary disease in hospitalised patients . One-hundred-and-seventy-three patients were enrolled; 164 were evaluable for clinical efficacy and 98 for bacteriological efficacy, with 144 pathogens isolated . The predominant pathogens were Haemophilus influenzae (n = 30), Streptococcus pneumoniae (18), Staphylococcus aureus (12), Pseudomonas aeruginosa (11), Moraxella catarrhalis (8), other Gram-negative bacteria (Neisseria, Klebsiella, Proteus, and Enterobacter spp.) (53) and other Gram-positive bacteria (12) . A single bacterial pathogen was identified in 61 patients, whereas two bacterial pathogens were isolated in 31 patients and three in six patients . The clinical response at the end of treatment was very high in both groups with a satisfactory outcome (cured or improved) in 97.6% of the meropenem patients and in 96.3% of the imipenem/cilastatin patients; at follow-up the rates were 89.1% and 89.8%, respectively . The bacterial success (eradication or presumed eradication) was 88.2% in the meropenem group and 89.4% in the comparator group . Nausea or vomiting were reported more frequently in patients treated with imipenem/cilastatin, whereas in the meropenem group an increase in aminotransferases was reported . One patient treated with imipenem/cilastatin was withdrawn from the study due to seizures . Meropenem and imipenem/cilastatin were highly effective for the treatment of severe bacterial exacerbations of chronic bronchitis but meropenem was better tolerated.

J Antimicrob Chemother, 1995 Jul, 36 Suppl A, 1 - 17
Meropenem: a microbiological overview; Edwards JR; Meropenem is a parenteral carbapenem antibiotic which has excellent bactericidal activity in vitro against almost all clinically significant aerobes and anaerobes . Its high activity is explained by ease of entry into bacteria combined with good affinity for essential penicillin binding proteins, including those associated with cell lysis . Breadth of spectrum is due, in part, to stability to all serine-based beta-lactamases, including those which hydrolyse third-generation cephalosporins . Meropenem has an antibacterial spectrum which is broadly similar to that of imipenem but, whilst slightly less active against staphylococci and enterococci, it is more active against Pseudomonas aeruginosa, all Enterobacteriaceae and Haemophilus influenzae . Amongst common human pathogens, only methicillin-resistant staphylococci and Enterococcus faecium are uniformly resistant to meropenem . The meropenem MICs for penicillin-resistant Streptococcus pneumoniae are higher than for penicillin-susceptible strains but the organisms remain susceptible . Clinical susceptibility in vitro to meropenem is defined by MICs of < or = 4 mg/L, intermediate susceptibility by MICs of 8 mg/L and MICs of > or = 16 mg/L define resistance; equivalent figures for zones of growth inhibition are > or = 14 (susceptible), 12-13 (intermediate) and < or = 11 (resistant) mm . Studies in guinea pig models of systemic infection and infections localised to the lungs, urinary tract and the central nervous system, some of which used immunocompromised animals, confirm the potential of meropenem demonstrated in vitro . These factors, combined with the human plasma, tissue or urinary concentrations of meropenem which exceed modal MICs for the pathogens isolated in clinical trials for most or all of the recommended 8 h dosing interval, predict that meropenem should be efficacious in the treatment of infections at many body sites.

J Antimicrob Chemother, 1995 Jul, 36(1), 201 - 7
An audit of ciprofloxacin use in a district general hospital; Speirs GE et al.; An audit of ciprofloxacin use at Southmead Hospital, Bristol was carried out for forty patients treated in early 1992 employing a modified Delphi technique with six assessors . Most patients assessed (20/40, 50%) had urinary tract infections (UTIs), 5/40 (12.5%) had chest infections, 4/40 (10%) had bacterial gastroenteritis and 3/40 (7.5%) had either bacteraemia or infection following an orthopaedic procedure . A likely bacterial pathogen was isolated from 32/40 (80%) of patients; 14/32 (44%) had Pseudomonas aeruginosa infections and from the remainder Enterobacteriaceae including Salmonella spp . (non-typhoid) were cultured . Oral therapy with ciprofloxacin was used in 37 (93%) of the 40 patients, and the three others received iv treatment . In 21/35 (60%) of patients where an assessment was made by majority scoring, a quinolone was felt to be clinically justified . A quinolone was least likely to be thought justified if the patient had a chest infection . The assessors had few concerns about the effectiveness or toxicity of ciprofloxacin but for 41% (14/34) of patients, where there was a majority opinion, a cheaper alternative was felt to be available; most of these patients had hospital-acquired UTIs caused by Enterobacteriaceae . The duration of therapy was felt to be too long in 35% (10/29) of patients, mainly because of prolonged treatment of UTIs . In some cases of P . aeruginosa infection the assessors would have used higher doses than those prescribed . Ciprofloxacin was the quinolone of choice in 24/32 (75%) of assessable cases . Norfloxacin was chosen to treat UTI due to multi-resistant Enterobacteriaceae in 6.2% (2/32) cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Med Clin North Am, 1995 Jul, 79(4), 721 - 32
Cefepime; Cunha BA et al.; Because of the popularity of some third-generation cephalosporins, emergence of resistant organisms (e.g., selected Enterobacteriaceae) that produce inducible and extended-spectrum beta-lactamases has been a problem . Cefepime's twice-a-day dosage schedule and enhanced activity against Enterobacteriaceae and gram-positive organisms give it several advantages over older drugs . The clinical efficacy of cefepime has been demonstrated in comparative and noncomparative trials in the United States and Europe . Cefepime with twice-daily dosing has been useful in the treatment of lower respiratory tract infections, urinary tract infections, skin and skin structure infections, and in serious infection, including those with associated bacteremia . Cefepime is comparable to ceftazidime in clinical and bacteriologic response rates when both agents are administered three times a day in febrile neutropenic patients . Cefepime is also active against organisms that show resistance to other agents . Several studies have shown that cefepime retains its activity against E . cloacae and E . coli strains resistant to other cephalosporins and against many strains of P . aeruginosa resistant to ceftazidime . Cefepime exhibits a low level of cross-resistance with third-generation cephalosporins and a low propensity for selection of resistant mutants and offers a low potential for the induction of bacterial resistance, which complicates the course of many patients treated with single-agent third-generation therapy . Cefepime should be used in place of ceftazidime based on resistance potential, activity against resistant organisms, and cost.

Infect Immun, 1995 Jul, 63(7), 2665 - 73
Monoclonal antibodies against Haemophilus lipopolysaccharides: clone DP8 specific for Haemophilus ducreyi and clone DH24 binding to lacto-N-neotetraose; Borrelli S et al.; Mouse monoclonal antibodies (MAbs) DP8 {immunoglobulin G1(kappa)} and DH24 {immunoglobulin M(kappa)}, which are specific for Haemophilus ducreyi lipopolysaccharide (LPS), were generated by fusing mouse myeloma NS0 cells with spleen cells of BALB/c mice immunized with a total membrane preparation of H . ducreyi . MAb DP8 reacted in whole-cell enzyme immunoassay (EIA) and colony dot immunoblotting with all 50 strains of H . ducreyi but not with any other bacteria tested, which suggests an exposed and species-specific epitope on the H . ducreyi cell surface . This conclusion was supported by the finding that DP8 bound to all six H . ducreyi LPSs tested but not to any of the Haemophilus influenzae or enterobacterial LPSs or synthetic glycoconjugates . The MAb DH24 bound to 43 of 50 strains of H . ducreyi and to few strains of H . influenzae, Neisseria gonorrhoeae, and Neisseria meningitidis, as evaluated by whole-cell EIA and colony dot immunoblotting . The MAb DH24 reacted with five of the six H . ducreyi LPSs tested and with the lacto-N-neotetraose (Gal beta 1-->4GlcNAc beta 1-->3Gal beta 1-->4Glc) series of synthetic glycoconjugates, as determined by EIA . By using polysaccharides obtained after both mild acidic hydrolysis and strong alkali treatment and dephosphorylated samples as inhibitors of the MAbs binding to H . ducreyi LPS antigens, it could be shown that phosphate groups were essential for the binding of DP8 to LPS but that they did not affect antigenic recognition by DH24 . None of the MAbs bound to isolated lipid A, but aggregation caused by the fatty acids of lipid A was essential for epitope recognition.

Ann Clin Lab Sci, 1995 Jul-Aug, 25(4), 283 - 90
Bacterial contamination of cellular blood components . A retrospective review at a large cancer center; Alvarez FE et al.; Concern over increased bacterial contamination prompted us to conduct a retrospective review of all bacterial cultures performed on cellular blood components at our institution between December 1989 and June 1993 . Sterility checks were accomplished by using the Bactec blood culture system . The breakdown of the units cultured versus units produced was as follows: Packed Red Blood Cells (PRBCs): 626 (0.6 percent)/102,593; Random Donor Platelets (RDPs): 523 (0.6 percent)/95,005; and Single Donor Platelets (SDPs): 97 (0.7 percent)/13,641 . The units were divided into groups with the following results (cultured/positive): (I) PRBCs implicated in transfusion reactions (159/5); (II) PRBCs issued and returned to lab after 30 minutes (155/0); (III) PRBCs expired on shelf (276/3); (IV) PRBCs used for quality control (QC) (36/0); (V) RDPs implicated in transfusion reactions (309/12); (VI) RDPs used for QC (214/3)); (VII) SDPs involved in transfusion reactions 43/2); and (VIII) SDPs used for QC (54/0) . Identification of isolates yielded: Group I = 4 coagulase negative Staphylococcus (CNS) and 1 Enterobacter agglomerans; Group III = 2 gram negative bacilli and 1 CNS; Group V = 12 CNS; Group VI = 2 CNS and 1 Pseudomonas paucimobilis: Group VII = 1 gram variable bacilli and 1 Enterococcus species . Overall, 1.3 percent of all PRBCs, 2.9 percent of all RDPs, and 2.1 percent of all SDPs cultured were positive for bacterial contamination . Although these percentages are low, given the increased susceptibility of immunosuppressed cancer patients, more intensive monitoring of bacterial contamination must be implemented to identify the source of infection.

J Med Assoc Thai, 1995 Jul, 78 Suppl 1, S36 - 9
Efficacy and contamination of in-use disinfectants in Rajavithi General Hospital; Kajanahareutai S et al.; Quality testing of disinfectant in-use in Rajavithi General Hospital was conducted to evaluate the germicidal activity and contamination . Two hundred and thirty-four samples of 4 commonly used disinfectants in operating rooms, labour rooms and the surgical intensive care unit were studied . Results showed that 2 of 126 samples of chlorhexidine/cetrimide 1:100 dilution were contaminated by P.maltophilia and A.xylosoxidans and failed the in-use test . One of 34 samples of phenolics yielded A.lowffii . Two of 16 hypochlorite 0.05% grew E.cloacae, Enterobacter spp., A.calcoaceticus and Pseudomonas spp . Forty-six samples of 1:500 and 1:100 of quaternary ammonium compound, and 12 samples of 1% hypochlorite were not contaminated . Bacterial contamination and failure to kill bacteria by disinfectants reflected improper preparation and use of these solutions . Periodic quality testing is clearly indicated.

Appl Environ Microbiol, 1995 Jul, 61(7), 2583 - 8
Decrease in culturability of Vibrio cholerae caused by glucose; Shiba T et al.; The culturability of Vibrio cholerae O1 serotype Inaba strain 569B was decreased by the addition of glucose to cell suspensions in starvation media . A similar effect was observed with sucrose, maltose, and fructose . We term this inhibitory effect glucose shock . It was not observed with arabinose or xylose or with carboxylates, such as acetate and pyruvate . No acidification of the medium occurred in the presence of these carbohydrates . Glucose shock was prevented by the addition of nitrogen or phosphorus sources . In the presence of phosphate, the bacterium produced formic acid from glucose . The phenomenon of glucose shock was also observed in V . cholerae O1 serotype Inaba strain RIMD 2203082 but not in strain RIMD 2203088 (O1 Inaba), IID 936 (O1 Ogawa), or RIMD 2214034 (non-O1) . The culturability of Escherichia coli, Enterobacter aerogenes, and Listonella anguillarum did not decrease in starvation media with added glucose . Hence, the phenomenon should have ecological significance in determining the distribution of bacteria in marine ecosystems in situations where carbohydrates are abundant, but nitrogen and phosphorus are limiting.

Appl Environ Microbiol, 1995 Jul, 61(7), 2548 - 53
Denitration of glycerol trinitrate by resting cells and cell extracts of Bacillus thuringiensis/cereus and Enterobacter agglomerans; Meng M et al.; A number of microorganisms were selected from soil and sediment samples which were known to have been previously exposed to nitrate ester contaminants . The two most effective bacteria for transforming glycerol trinitrate (GTN) were identified as Bacillus thuringiensis/cereus and Enterobacter agglomerans . For both isolates, denitration activities were expressed constitutively and GTN was not required for induction . Dialysis of cell extracts from both isolates did not affect denitration, which indicates that dissociable and depletable cofactors are not required for denitration . With thin-layer chromatography and high-performance liquid chromatography, the denitration pathway for both isolates was shown to be a sequential denitration of GTN to glycerol dinitrate isomers, glycerol mononitrate isomers, and ultimately to glycerol . GTN was observed to be completely converted to glycerol during a long-term incubation of cell extracts.

J Bacteriol, 1995 Jul, 177(14), 4183 - 6
Detection of XerC and XerD recombinases in gram-negative bacteria of the family Enterobacteriaceae; Sirois S et al.; XerC and XerD are site-specific recombinases of the lambda integrase family which resolve multimeric replicons to monomers by acting at specific sites such as cer, ckr, nmr, parB, and psi, which are found in plasmids, or at the dif site found in the Escherichia coli chromosome . By using Southern hybridizations to cloned E . coli xerC and xerD genes and a cer-nmr plasmid-based resolution assay, the presence of these genes in several species of Enterobacteriaceae is shown.

J Bacteriol, 1995 Jul, 177(14), 4097 - 104
Comparative analysis of extreme acid survival in Salmonella typhimurium, Shigella flexneri, and Escherichia coli; Lin J et al.; Several members of the family Enterobacteriaceae were examined for differences in extreme acid survival strategies . A surprising degree of variety was found between three related genera . The minimum growth pH of Salmonella typhimurium was shown to be significantly lower (pH 4.0) than that of either Escherichia coli (pH 4.4) or Shigella flexneri (pH 4.8), yet E . coli and S . flexneri both survive exposure to lower pH levels (2 to 2.5) than S . typhimurium (pH 3.0) in complex medium . S . typhimurium and E . coli but not S . flexneri expressed low-pH-inducible log-phase and stationary-phase acid tolerance response (ATR) systems that function in minimal or complex medium to protect cells to pH 3.0 . All of the organisms also expressed a pH-independent general stress resistance system that contributed to acid survival during stationary phase . E . coli and S . flexneri possessed several acid survival systems (termed acid resistance {AR}) that were not demonstrable in S . typhimurium . These additional AR systems protected cells to pH 2.5 and below but required supplementation of minimal medium for either induction or function . One acid-inducible AR system required oxidative growth in complex medium for expression but successfully protected cells to pH 2.5 in unsupplemented minimal medium, while two other AR systems important for fermentatively grown cells required the addition of either glutamate or arginine during pH 2.5 acid challenge . The arginine AR system was only observed in E . coli and required stationary-phase induction in acidified complex medium . The product of the adi locus, arginine decarboxylase, was responsible for arginine-based acid survival.

J Child Neurol, 1995 Jul, 10(4), 283 - 8
Brain abscess in children: microbiology and management; Brook I; Brain abscess is a serious, life-threatening infection . The infection can originate from contiguous sites of existing infections, such as chronic otitis media, dental infection, mastoiditis, or sinusitis, where anaerobic bacteria predominate . The infection can also occur in children with cyanotic congenital heart disease, in whom the predominant organisms are viridans, microaerophilic, or anaerobic streptococci, or after head trauma, in which case Staphylococcus aureus, viridans cocci, and Streptococcus pneumoniae are the most prevalent isolates . Enterobacteriaceae, Pseudomonas aeruginosa, yeast, fungi, and mycobacteria are prevalent in the immunocompromised . Radioisotope brain scans, computed tomography, and magnetic resonance imaging are important tools that enable accurate diagnosis of the infection . Proper selection of antimicrobial with good intracranial penetration is essential in the management of intracranial infection . Delay in surgical drainage can be associated with high mortality or morbidity . However, brain abscess, especially in the early phase of cerebritis, may respond to antimicrobial therapy without surgical drainage.

Heart Lung, 1995 Jul-Aug, 24(4), 342 - 4
Bilateral suppurative thrombophlebitis due to Staphylococcus aureus; Villani C et al.; Suppurative thrombophlebitis is an infection of the wall of a superficial vein, usually is associated with intravenous catheter placement, and accounts for about 10% of all nosocomial infections . Suppurative thrombophlebitis occurs most commonly in patients with burns, patients with cancer, and persons receiving steroids . Skin flora organisms (e.g., Staphylococcus aureus and to a lesser extent Enterobacteriaceae) are the most common pathogens . Suppurative thrombophlebitis should be suspected when a patient having phlebitis presents with a temperature of 102 degrees F or higher . The diagnosis of suppurative thrombophlebitis is usually straightforward and made by demonstration of pus coming from the wound of the removed intravenous device or by aspiration of pus percutaneously from the involved vein . Treatment of superficial suppurative thrombophlebitis consists of venotomy of the affected vessel and systemic antimicrobial therapy . We present a case of S . aureus bilateral suppurative thrombophlebitis, which is most unusual.

Bioconjug Chem, 1995 Jul-Aug, 6(4), 389 - 94
Poly(ethylene glycol)-doxorubicin conjugates containing beta-lactamase-sensitive linkers; Senter PD et al.; 7-Aminocephalosporin doxorubicin (AC-Dox) was condensed with monomethoxypoly(ethylene glycol)-propionic acid N-hydroxysuccinimide ester (5 kDa) or with a branched form of poly(ethylene glycol)-propionic acid N-hydroxysuccinimide ester (10 kDa), forming M-PEG-AC-Dox and B-PEG-AC-Dox, respectively . These polymer drug derivatives were designed such that doxorubicin would be released upon Enterobacter cloacae beta-lactamase (bL)-catalyzed hydrolysis . Both M-PEG-AC-Dox (IC50 = 80 microM) and B-PEG-AC-Dox (IC50 = 8 microM) were less toxic to H2981 human lung adenocarcinoma cells than doxorubicin (IC50 = 0.1-0.2 microM) and could be activated in an immunologically specific manner by L6-bL, a monoclonal antibody-bL conjugate that bound to H2981 cell surface antigens . In addition, the polymers were relatively stable in mouse plasma (< 26% hydrolysis after 24 h at 37 degrees C) and were less toxic to mice (maximum tolerated dose > 52 mumol/kg) than doxorubicin (maximum tolerated dose = 13.8 mumol/kg) . Pharmacokientic studies were performed in mice bearing subcutaneous 3677 melanoma tumors . B-PEG-AC-Dox cleared from the blood more slowly than M-PEG-AC-Dox and was retained to a 2.1-fold greater extent in human 3677 melanoma tumor xenografts over a 4 h period . The intratumoral concentrations of both polymers far exceeded that of doxorubicin . Thus, the PEG-AC-Dox polymers offer the possibility of generating large intratumoral doxorubicin concentrations owing to their reduced toxicities, the amounts that accumulate in tumors, and the fact that doxorubicin is released upon beta-lactam ring hydrolysis.

Urol Nefrol (Mosk), 1995 Jul-Aug, (4), 4 - 8
{The etiological factors in pyelonephritis occurring against a background of nephrolithiasis}; Savitskaia KI et al.; 656 urine and 78 blood samples were examined immunomicrobiologically . No bacterial growth was recorded in 43.8% of urine samples . Opportunistic bacteria were represented by Enterobacteriaceae, nonfermenting gram-negative bacteria with predominance of E . coli, P . mirabilis, P . aeruginosa isolated both in monocultures and in associations in conventional diagnostic titers (1g 5 CFU/ml) . Throughout 40 days of the hospital stay microflora continuously changed, but until the discharge the infection persisted . The study of the immunological aspect of anti-infection resistance showed that most of the examinees (73%) at admission with pyelonephritis exacerbation have deficient cellular and humoral defense.

Pediatr Infect Dis J, 1995 Jul, 14(7 Suppl), S88 - 92
Ceftibuten: minimal inhibitory concentrations, postantibiotic effect and beta-lactamase stability--a rationale for dosing programs; Neu HC; Ceftibuten, a new orally absorbed cephalosporin with a novel side chain, has broad in vitro activity against most of the important respiratory pathogens including Streptococcus pneumoniae and both beta-lactamase-negative and beta-lactamase-positive Haemophilus influenzae and Moraxella (Branhamella) catarrhalis . Furthermore it has high activity against Enterobacteriaceae, which contain classic TEM-1 beta-lactamases and those containing the new extended spectrum beta-lactamases, which hydrolyze parenteral third generation cephalosporins . Studies have shown that ceftibuten has a postantibiotic effect comparable to that of other beta-lactams against S . pneumoniae, H . influenzae and M . catarrhalis . Blood levels achieved after a single 400-mg dose given once daily or 9 mg/kg/day taken once daily for children yield blood levels and postantibiotic inhibition for the majority of a dosing period . The in vitro and pharmacokinetic data can be correlated to provide reasonable dosing programs for the new oral cephalosporins.

J Clin Microbiol, 1995 Jul, 33(7), 1779 - 83
Analysis of clonal relationships among isolates of Shigella sonnei by different molecular typing methods; Liu PY et al.; Shigella sonnei is a major cause of diarrheal disease in developed as well as in developing countries . Epidemiologic studies of this organism have been limited by the lack of a simple and effective method for comparing strains . In this study, we have compared different molecular typing methods, i.e., plasmid profile analysis, restriction endonuclease analysis of plasmids, rRNA gene restriction analysis (ribotyping), pulsed-field gel electrophoresis (PFGE), and enterobacterial repetitive intergenic consensus (ERIC) sequence-based PCR (ERIC-PCR) for typing 20 clinical isolates of S . sonnei collected from six incidents of infection . PFGE and ERIC-PCR fingerprintings had the highest discriminatory power for discrimination of epidemiologically related isolates from epidemiologically unrelated strains of S . sonnei, and both gave seven distinct strain types among these isolates and the type strain of the species . Plasmid study and ribotyping produced only six and typing techniques demonstrated two distinct patterns, respectively, among these strains . All of these molecular an identical fingerprint for eight temporally related sporadic isolates . It is possible that these temporally related isolates belonged to a single bacterial clone and circulated obscurely through the community . Our results indicate that the ERIC-PCR technique represents a rapid and simple means for typing S . sonnei with a level of discrimination equivalent to that of PFGE but greater than those of plasmid profile analysis, restriction endonuclease analysis of plasmids, and ribotyping.

Antimicrob Agents Chemother, 1995 Jul, 39(7), 1472 - 9
Antibacterial activity of WY-49605 compared with those of six other oral agents and selection of disk content for disk diffusion susceptibility testing; Fuchs PC et al.; The in vitro antimicrobial activity of an oral penem, WY-49605, was compared with those of six other oral antimicrobial agents against 598 bacterial isolates representing 51 different species . WY-49605 exhibited good activity against most gram-positive bacteria and members of the family Enterobacteriaceae . It had little activity against nonfermenting gram-negative bacilli, Enterobacter spp., Serratia spp., enterococci, Staphylococcus haemolyticus, and methicillin-resistant Staphylococcus aureus . Its activity was unaffected by the beta-lactamases of Neisseria gonorrhoeae, Haemophilus influenzae, and staphylococci . Disk diffusion susceptibility tests were performed with 5-, 10-, 15-, and 30-micrograms WY-49605 disks . The 5-micrograms disk is recommended, with tentative breakpoints of > or = 16 mm for susceptibility (MIC, < or = 2.0 microgram/ml) and < or = 12 mm for resistance (MIC, > or = 8.0 micrograms/ml).

Eur J Surg, 1995 Jul, 161(7), 513 - 8
Fibre is an essential ingredient of enteral diets to limit bacterial translocation in rats; Spaeth G et al.; OBJECTIVE: To assess the effect of six different enteral diets on the gut barrier . DESIGN: Laboratory study . SETTING: University hospital, Germany . MATERIAL: 70 Specific pathogen free female Crl:CDR BR rats . INTERVENTIONS: For 7 days, 6 groups of rats were fed orally with standard chow (n = 15); total parenteral nutrition solution (oral TPN, n = 15); elemental diet (ED, n = 10); nutrient-defined diet (NDD, n = 10); or the NDD supplemented with uracil (NDD+uracil, n = 10), or fibre (NDD+fibre, n = 10) . MAIN OUTCOME MEASURES: Bacterial translocation to mesenteric lymph nodes, numbers of Gram negative enterobacteria and total aerobic bacteria in the caecum, and intestinal concentrations of secretory IgA . RESULTS: The incidence of bacterial translocation was significantly increased in the groups given oral TPN, ED, NDD, and NDD+uracil compared with the group given chow . Only NDD+fibre resulted in a similar degree of translocation to that in the chow group . All groups in which there was increased translocation had a highly significant overgrowth of aerobic bacteria in the caecum, mainly by Gram negative enteric organisms . The secretory IgA concentration was reduced in the group that had been given oral TPN, and that in the ED and NDD+uracil groups was similar to that in the chow group . NDD and NDD+fibre were associated with higher intestinal concentrations of secretory IgA than chow . CONCLUSION: Fibre-free enteral diets do not protect the gut antimicrobial barrier whatever else is in them . The superiority of early enteral as opposed to parenteral nutrition after injury may, therefore, not be the result of a specific protective effect on the gut barrier . The supplementation of commercial enteral diets with bulk fibre should be tested in clinical trials.

Mol Gen Mikrobiol Virusol, 1995 Jul-Sep, (3), 26 - 9
The established Yersinia pestis biovars are characterized by typical patterns of I-CeuI restriction fragment length polymorphism; Rakin A et al.; The genomes of three main biovars of Yersinia pestis were subjected to restriction fragment length polymorphism analysis using I-CeuI endonuclease . I-CeuI which is encoded by a mobile intron in Chlamydomonas engamenans recognizes a 25-bp site in the ribosomal RNA rrl gene and cuts DNA of most representatives of Enterobacteriaceae into seven fragments corresponding to the presence of seven rrn-operons . Glycerol-positive Y . pestis strains (biovars antiqua and mediaevalis) contain seven ribosomal operons which can be recognized by I-CeuI endonuclease . However, glycerol-negative strains of Y . pestis biovar orientalis expose only six restriction sites for I-CeuI . The restriction fragment length polymorphism patterns obtained with I-CeuI make it possible to distinguish between three biovars of Y . pestis . Use of another rare cutting restriction enzyme, Bln/I, permits differentiation between pigment-adsorbing and avirulent non-pigment-adsorbing Y . pestis . Still, due to homologous recombination between the two copies of IS 100 insertion sequence bracketing the pgm-locus, the mechanism of deletions in the pgm-locus seems to be confined only to strains of biovars antiqua and mediaevalis, and can be different in Y . pestis strains of biovar orientalis . The I-CeuI restriction patterns of two Yersinia strains isolated within a ten-year period in the port of St . Petersburg and originally identified as Y . pseudotuberculosis 01 turned out to be related to typical representatives of Y . pestis biovar antiqua . These strains could be exported from the same source or circulate among Rattus norvegicus population of the port as non-pigment-adsorbing avirulent immunogenic clone.

FEMS Microbiol Lett, 1995 Jun 15, 129(2-3), 273 - 9
Biological and immunological comparisons of Enterobacter cloacae and Escherichia coli porins; Mallea M et al.; Bacteriocin susceptibilities indicate that during cloacin DF13 uptake the F porin of Enterobacter cloacae plays a similar role to that reported for the OmpF porin of Escherichia coli during colicin A entry . The translocatory activities of these two porins during the bacteriocin uptake can be substituted by the porins D and OmpC, respectively, under conditions not requiring the receptor binding step . Using anti-peptide antibodies, a peptide located in the internal loop L3 of the Escherichia coli OmpF porin was identified in the D and F porins of Enterobacter cloacae . The results demonstrated the existence of a close relationship between porins in terms of both antigenic determinants and bacteriocin susceptibilities.

Presse Med, 1995 Jun 10, 24(21), 979 - 82
{Comparative epidemiology of the resistance of enterobacteriaceae, Staphylococcus and Pseudomonas aeruginosa to fluoroquinolones in an outpatient study}; Weber P et al.; OBJECTIVES: Since the clinical introduction of fluoroquinolones in general practice for the treatment of a wide range of infections, we have carried out an annual survey of the susceptibilities of Enterobacteriaceae, Staphylococcus and Pseudomonas aeruginosa isolated from domiciliary infections to quinolones (nalidixic acid and ofloxacin) as well as to amoxycillin, co-amoxyclav and co-trimoxazole . METHODS: From 1990 to 1993, within the same three month period of the year, a total of 1750 strains were collected at three private clinical laboratories in greater Paris . The in vitro activities of antibiotics were evaluated using the standard disc-diffusion test . MICs of ofloxacin were determined for all intermediate and resistant strains . RESULTS: Resistance to quinolones remained unchanged during this four year period . Among Enterobacteriaceae, less than 3% of strains were resistant to fluoroquinolones . A regular decrease in the annual percentage of co-amoxyclav susceptible strains was noted: from 82.4% in 1990 to 68.1% in 1993 (p < 0.001) . Resistance (intermediate plus resistant strains) was more frequent in patients more than 60 years old, in those who had received quinolones up to one month before specimen collection or in those who had been recently (within 3 months) hospitalised . Similar data were obtained for amoxycillin or co-amoxyclav . CONCLUSION: Our study, together with those performed by other European investigators, demonstrates that the prevalence of quinolone resistant strains in general practice remains low and stable despite high consumption of fluoroquinolones.

Adv Ther, 1995 Jul-Aug, 12(4), 222 - 35
Cost-effective management of complicated urinary tract infections; Cox CE; Complicated urinary tract infection (UTI), which often requires hospitalization or prolongs a hospital stay, presents numerous diagnostic and therapeutic challenges . Implementation of effective antimicrobial treatment is vital because of the risk of adverse sequelae due to persistence of infection, relapse, or reinfection . Further, the increasing resistance of common uropathogens, such as Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacter species, can complicate the therapeutic outcome . Economic factors also mandate cost-effective therapy . The costs of managing adverse sequelae have placed a significant liability on an already overburdened health care system . Estimates for prolonged hospitalization due to nosocomial UTI are reported as high as $2 billion a year in the United States . When parenteral rather than oral antimicrobial therapy is used, additional health care costs approximate $1000 per day per patient . Given the resistance to commonly used medications and the risk of serious adverse sequelae, clinicians are seeking more appropriate therapy . New oral antimicrobial agents now permit outpatient management of complicated UTIs that formerly required hospitalization for prolonged treatment . Currently, quinolones are recommended as first-line agents for complicated UTI . Reviews of pharmacokinetics, antimicrobial activity, efficacy, and safety of these drugs have noted equipotence or superiority to other antimicrobials, including trimethoprim/sulfamethoxazole . When used appropriately, quinolones provide effective and safe therapy for complicated UTI and offer in vitro efficacy against a broad range of pathogens.

Lett Appl Microbiol, 1995 Jun, 20(6), 333 - 7
An assessment of environmental factors influencing acid tolerance and sensitivity in Escherichia coli, Salmonella spp . and other enterobacteria; Rowbury RJ; Environmental factors such as temperature, pH and nutrient level affect enterobacterial acid sensitivity, as do the presence of phosphate and Na+ and the extent of aeration . The mechanisms governing these effects are partially understood and the involvement of phoE, fur and atp in acid tolerance, of phoE, envZ, tonB, (p)ppGpp and cAMP in salt-induced acid sensitivity and of rpoS in stationary-phase acid tolerance are of particular interest . It should be noted that surface attachment enhances acid resistance.

Cancer Res, 1995 Jun 1, 55(11), 2357 - 65
In vitro and in vivo activities of a doxorubicin prodrug in combination with monoclonal antibody beta-lactamase conjugates; Svensson HP et al.; A cephalosporin derivative of doxorubicin (C-Dox) was evaluated as a prodrug for activation by mAb conjugates of the beta-lactamase from Enterobacter cloacae P99 (beta L; EC 3.5.2.6) . The conjugates consisted of beta L and the F(ab') fragments of either of the mAbs L6, P1.17, or 96.5 . L6 binds to antigens on a variety of carcinomas, including the two lung adenocarcinoma cell lines H2981 and H2987 used in this study . 96.5 binds to the melanoma-associated antigen p97, and P1.17 was used for the control conjugate . C-Dox was found to be less cytotoxic to three different tumor cell lines in vitro compared to the parent drug doxorubicin (Dox) . Immunospecific activation took place when the cells were pretreated with beta L conjugates that could bind to antigens on the tumor cells . In vivo toxicity and pharmacokinetics studies in athymic female nu/nu mice revealed that C-Dox was at least 7-fold less toxic than Dox (on a molar basis), despite the fact that a > or = 320-fold greater area-under-the-curve (blood concentration versus time) of C-Dox compared to Dox was obtained 0-2 h after administration of the two agents . Pharmacokinetic studies at maximum tolerated doses in mice bearing xenografts of either H2981 or H2987 revealed that the intratumoral levels of Dox after treatment with L6-beta L in combination with C-Dox were higher than were obtained by either systemic treatment with Dox or a combination of P1.17-beta L and C-Dox . This finding suggested that the conversion of C-Dox to Dox was tumor specific and dependent on the presence of the targeted antigen . Furthermore, the best antitumor activity against both H2981 and H2987 tumors was obtained by treatment with L6-beta L and C-Dox compared to P1.17-beta L and C-Dox or Dox alone . Thus, higher levels of Dox corresponded to greater therapeutic effects in both of the tumor models studied.

Infect Control Hosp Epidemiol, 1995 Jun, 16(6), 331 - 4
Focused microbiological surveillance and gram-negative beta-lactamase--mediated resistance in an intensive care unit; Bryce EA et al.; OBJECTIVE: To evaluate the use of focused surveillance in following resistance patterns within an intensive care unit (ICU) . DESIGN: Antibiograms of 167 gram-negative isolates from ICU patients were compared to the hospitalwide antibiograms . ICU isolates were examined for the newer forms of beta-lactamase resistance . An outbreak of multiresistant Pseudomonas aeruginosa during the survey illustrated the usefulness of focused surveillance in early intervention and containment . SETTING: A 700-bed adult tertiary care hospital with a 16-bed medical and surgical ICU . RESULTS: Hospitalwide and ICU antibiograms of the Enterobacteriaceae were similar . However, resistance of P aeruginosa in the ICU was underestimated by hospitalwide rates . Susceptibility of ICU isolates to ceftazidime, ciprofloxacin, and piperacillin was 54%, 54%, and 42%, compared with 81%, 77%, and 85%, respectively, in the hospital at large . Thirty-five percent of isolates exhibited one of the newer forms of beta-lactamase-mediated resistance, with 17% of isolates exhibiting Class I cephalosporinase production . CONCLUSION: Targeted survey of high antibiotic-use hospital units should be used to study bacterial epidemiology, rather than relying on general hospital data to evaluate patterns of antimicrobial resistance . Monitoring of potential problem areas leads to prompt identification of changes in resistance and allows early intervention.

J Clin Microbiol, 1995 Jun, 33(6), 1606 - 12
Comparative study of five different DNA fingerprint techniques for molecular typing of Streptococcus pneumoniae strains; Hermans PW et al.; The aim of this study was to identify the strengths and weaknesses of five DNA fingerprint methods for epidemiological typing of Streptococcus pneumoniae . We investigated the usefulness of (i) ribotyping, (ii) BOX fingerprinting with the BOX repetitive sequence of S . pneumoniae as a DNA probe, (iii) PCR fingerprinting with a primer homologous to the enterobacterial repetitive intergenic consensus sequence, (iv) pulsed-field gel electrophoresis of large DNA fragments, and (v) restriction fragment end labeling to detect restriction fragment length polymorphism of small DNA fragments . Twenty-eight S . pneumoniae strains isolated from the blood and/or cerebrospinal fluid of 21 patients were analyzed . Genetic clustering among the 28 strains was independent of the DNA fingerprint technique used . However, the discriminatory power and the similarity values differed significantly among the individual techniques . BOX fingerprinting, pulsed-field gel electrophoresis, and restriction fragment end labeling provided the highest degree of discriminatory power . Furthermore, the ease with which computerized fingerprint analysis could be conducted also varied significantly among the techniques . Ribotyping, BOX fingerprinting, and restriction fragment end labeling were very suitable techniques for accurate computerized data analysis . Because of their high discriminatory potential and ease of accurate analysis, we conclude that BOX fingerprinting and restriction fragment end labeling are the most suitable techniques to type pneumococcal strains.

Poult Sci, 1995 Jun, 74(6), 1044 - 8
The effects of extended chilling times with acetic acid on the temperature and microbiological quality of processed poultry carcasses; Dickens JA et al.; The effects of extended chill times with and without .6% acetic acid and agitation on the microbiological quality of broiler carcasses were determined . Carcasses were chilled for either 1, 2, or 3 h using the following treatments: 1) paddle chiller without acid (C); 2) static ice slush with .6% acetic acid (S); 3) static ice slush with air agitation and .6% acetic acid (SA); and 4) a paddle type chiller with .6% acetic acid (P) . Whole carcass rinse samples were taken at 1, 2, and 3 h (two per time per treatment) and evaluated for total aerobes and Enterobacteriaceae and at 1 and 2 h for Salmonella incidence . Six replications of 24 carcasses per replication were used for the standard microbiological evaluations and five runs of 24 carcasses per run were used for the determination of Salmonella incidence . Total aerobes were reduced (P < or = .05) by .34, .62, and 1.16 log10 most probable number/mL for the S, SA, and P treatments, respectively, when compared with the controls . Enterobacteriaceae counts were reduced (P < or = .05) by .50, .71, and 1.4 log10 for the S, SA, and the P treatments, respectively . Salmonella incidence, from inoculated carcasses, after 1 h were 87% for the C carcasses, 80% for the S treatment, 53% for the SA treatment, and 6.7% for the P treatment.

J Appl Bacteriol, 1995 Jun, 78(6), 630 - 5
Isolation and properties of free and immobilized beta-galactosidase from the psychorotrophic enterobacterium Buttiauxella agrestis (strain NC4); Amarita F et al.; A study of the beta-galactosidase produced by the psychrotrophic bacterium Buttiauxella agrestis has been carried out . This micro-organism was isolated from raw milk and the enzyme isolated using standard methods . Molecular mass was estimated to be 515 kDa . The isoelectric point was close to 4.45 . Optimum pH was 7.25 . Maximal activity was observed at 50 degrees C and activation energy was estimated to be 39.1 kJ mol-1 . Lactose enhanced thermal stability . Using p-nitrophenyl-beta-D-galactopyranoside as the substrate, the Km was 11 mumol l-1 and Vmax was 85 U mg-1 protein . beta-Mercaptoethanol and ethanol were inhibitors; glycerol acted as a complex effector . The enzyme required divalent cations for activity while it was inhibited by EDTA . When the enzyme was immobilized in diethyl aminoethylcellulose the optimum pH of activity was 8 . Km was 47 mumol l-1 and Vmax was 96 U mg-1 protein.

J Chemother, 1995 Jun, 7(3), 197 - 200
In vitro activity of levofloxacin and FK-037 against aerobic isolates from spontaneous bacterial peritonitis; Cormican MG et al.; Spontaneous bacterial peritonitis is a potentially fatal complication of ascites, most often caused by the Enterobacteriaceae or streptococci . We have evaluated the in vitro activity of FK-037, a new cephalosporin, cefotaxime, cefpirome, ceftazidime, levofloxacin, and ofloxacin against a collection of 124 isolates from patients with spontaneous bacterial peritonitis . Levofloxacin (< or = 2 mg/L) was active against all isolates and ofloxacin (< or = 2 mg/L) against 98.4% of isolates . The cephalosporins (< or = 8 mg/L) were less active against cefpirome = 95.4%, FK-037 = 94.4%, and cefotaxime and ceftazidime = 91.1% . Given the high mortality associated with spontaneous bacterial peritonitis, clinical studies of the quinolones (specifically of levofloxacin) and the alternative cephalosporins presented for treatment of spontaneous bacterial peritonitis appears warranted.

J Chemother, 1995 Jun, 7(3), 171 - 4
Loss of porins following carbapenem-resistance selection and adherence modification in enterobacteria; Raimondi A et al.; The acquired resistance to the carbapenems is frequently joined to modified expression of porins or other outer membrane (OM) structures, thus bacterial adherence, that also depends on the presence of peculiar surface structures, might theoretically be influenced . In this study the ability to adhere to Hep-2 and I-407 eukaryotic cell monolayers was assayed for two susceptible strains of Serratia marcescens, one strain of Enterobacter cloacae and one of Providencia rettgeri in comparison with that of isogenic resistant mutants selected either by carbapenems or by cephalosporins . The mutants appeared slightly less adherent than the wild type strains, however, due to the high variability of this kind of assay, the differences observed in most cases could not be considered statistically significant . The data suggest that adherence, among the factors affecting the pathogenicity of the strains, remains probably unmodified in the resistant bacterial population possibly selected by a carbapenem treatment.

J Antimicrob Chemother, 1995 Jun, 35(6), 805 - 19
Chemotherapeutic activity of levofloxacin (HR 355, DR-3355) against systemic and localized infections in laboratory animals; Klesel N et al.; Ofloxacin, its optical isomers levofloxacin (HR 355, DR-3355) and D-ofloxacin (DR-3354) and ciprofloxacin were administered orally to mice and rats which had systemic and localized infections . Both levofloxacin and ciprofloxacin were equally effective in treating systemic murine infections caused by staphylococci . Enterobacteriaceae or Pseudomonas aeruginosa with ED50s ranging from 0.18 to 15.8 mg/kg and 0.42 to 16.3 mg/kg respectively and both these agents were twice as effective as ofloxacin which had an ED50 0.41 to 39.7 mg/kg . In contrast, D-ofloxacin was either inactive or exhibited only modest chemotherapeutic activity against the staphylococci and the Gram-negative organisms tested . When given to mice to treat staphylococcal abscesses and lung infections due to Klebsiella pneumoniae DT-S levofloxacin was up to four times more effective and produced a more pronounced bactericidal effect against the pathogens in vivo than the reference compounds . Despite possessing a similar, if not lesser, in-vitro activity against the infecting pathogens, levofloxacin was more effective than ofloxacin and ciprofloxacin in rats with localized infections caused by Enterobacteriaceae and P . aeruginosa.

J Antimicrob Chemother, 1995 Jun, 35(6), 765 - 73
Activity of cefepime against ceftazidime-resistant gram-negative bacilli using low and high inocula; Johnson CC et al.; Cefepime is a broad-spectrum cephalosporin that is reported to have enhanced activity against ceftazidime-resistant Gram-negative bacilli . In this study the effects of varying inoculum size on in-vitro susceptibility to cefepime and other selected antimicrobial agents were determined by agar dilution MICs and in time-kill studies . Among strains of Pseudomonas aeruginosa (n = 55) and Enterobacter spp (n = 56) that had previously been identified as ceftazidime-resistant, 73% and 96% were susceptible to cefepime (MIC < or = 16 mg/L), respectively, when tested with an inoculum of 10(4) cfu . However, with an inoculum of 10(7) cfu, 98% and 100% of strains were resistant, respectively . Furthermore, the bactericidal activity of cefepime against ceftazidime-resistant isolates was also inoculum-dependent . In time-kill studies, bactericidal action was obtained only at the lowest concentration of organisms (10(4) cfu/mL) . beta-Lactamase extracted from an isolate of P . aeruginosa that demonstrated an inoculum effect had a lower affinity for cefepime than for ceftazidime . Overall, cefepime proved to be more resistant to hydrolysis by the beta-lactamase . However, differences in kinetics of the beta-lactamase against cefepime or ceftazidime do not appear to be of consequence in determining susceptibility of P . aeruginosa and Enterobacter spp . at high bacterial densities, since most strains with chromosomally-mediated beta-lactamase are highly resistant.

Clin Invest Med, 1995 Jun, 18(3), 168 - 76
Microbial surveillance of human islet isolation, in vitro culture, and cryopreservation; Lakey JR et al.; The aim of these studies was to investigate microbiological contamination during the isolation and preservation of islets of Langerhans in a low-temperature tissue bank . Islets were isolated from the pancreases of 117 organ donors, then cryopreserved . In the initial 47, microbial culture was completed only after thawing: Enterobacter cloacae (n = 4) and gram-negative bacilli (n = 9) were isolated for a positive culture rate of 27.6% . It was not possible to ascertain the source of the contaminants, since cultures were taken only at the conclusion . A total of 70 consecutive pancreases were then subjected to islet isolation and cryopreservation while prospectively culturing at these steps: step 1, from the pancreas transport media; step 2, after intraductal perfusion of collagenase; step 3, after dissociation; step 4, after purification; step 5, following a 6-48-h in vitro culture; step 6, post-thaw; step 7, after dilution of the cryoprotective agent; and step 8, after final 48-h in vitro culture . The transport fluid was infected with aerobic gram-negative (n = 6), gram-positive (n = 5), and yeast microorganisms (n = 2) for an overall step 1 contamination rate of 19% . These contaminants were found in 9% of our local program vs . 26% from distantly procured pancreases . Contaminants at subsequent steps were 10% (step 2), 9% (step 3), so that only 3% were infected at the conclusion of isolation (step 4), and 0% after initial culture (step 5) . Amongst pancreases that were initially sterile, new contaminants could be identified in 12% at step 2 and 8% at step 3; however, these also became undetectable.(ABSTRACT TRUNCATED AT 250 WORDS)

J Formos Med Assoc, 1995 Jun, 94(6), 309 - 12
Treatment of pyogenic splenic abscess: nonsurgical procedures; Jang TN et al.; This paper reviews 10 cases of splenic abscess seen from January 1984 to December 1993 . Predisposing conditions included preceding pyogenic infections, contiguous infection, trauma, and diabetes . Fever, chills and pain over the left upper quadrant of the abdomen were the most common symptoms . Routine laboratory tests uncovered common abnormalities which included marked leukocytosis and abnormal chest film with left pleural effusion . All 10 patients had a solitary abscess . Enterobacteriaceae and anaerobes were the most common offending organisms and one patient had polymicrobial infections . Nine of the 10 patients were successfully treated with percutaneous sonographically-guided drainage without significant complications . Only one patient underwent splenectomy because of rupture of the splenic abscess into the peritoneal cavity . All 10 patients survived . This review indicates that percutaneous drainage may replace splenectomy as the initial approach in cases of a solitary splenic abscess.

Clin Infect Dis, 1995 Jun, 20(6), 1551 - 2
Simian bites and bacterial infection; Goldstein EJ et al.; Three patients with simian bites and resultant infection are described . The bacteriology of the wounds was diverse and included alpha-hemolytic streptococci and other streptococci in all wounds, enterococci, Staphylococcus epidermidis, and Enterobacteriaceae . A literature review revealed brief mentions of 132 cases of simian bites in some of which Bacteroides species, Fusobacterium species, and Eikenella corrodens were isolated . Infection, despite antimicrobial therapy, and complications, such as osteomyelitis and flexion contractures, occurred frequently.

J Vet Med Sci, 1995 Jun, 57(3), 559 - 61
Biochemical and antigenical characterization of tannin-protein complex degrading enterobacteria isolated from koalas, Phascolarctos cinereus; Nakai Y et al.; Biochemical and antigenical characteristics of tannin-protein complex degrading enterobacteria (T-PCDE) isolated from Koalas, Phascolarctos cinereus, were investigated . T-PCDE had a specific profile of characteristics, and T-PCDE was distinguished from those of 12 type strains of Enterobacteriaceae used.

Gene . 1995 May 19;157(1-2):59.
BsuCI, a type-I restriction-modification system in Bacillus subtilis; Xu G et al.; A type-I R-M system was identified in B . subtilis . The genes comprising the system have striking similarity to type-I R-M systems observed in Enterobacteriaceae.

Am Fam Physician, 1995 May 15, 51(7), 1695 - 8
Parenteral beta-lactamase inhibitor combinations for clinical use; Manzella JP; Beta-lactamase enzymes are commonly produced by staphylococci, the Enterobacteriaceae, Pseudomonas aeruginosa and certain anaerobic organisms, such as Bacteroides fragilis . The production of beta lactamases is an important mechanism through which bacteria become resistant to antibiotics . The currently marketed beta-lactamase inhibitor combinations include ampicillin-sulbactam, ticarcillin-clavulanate potassium and, more recently, piperacillin-tazobactam . These extended spectrum antibiotic combinations share the ability to inhibit methicillin-susceptible staphylococci, nearly all anaerobic bacteria and many Enterobacteriaceae . Ticarcillin-clavulanate potassium and piperacillin-tazobactam also have activity against P . aeruginosa . The combination agents are useful in the treatment of moderate to severe infections, particularly when a polymicrobial etiology is suspected or documented.

Klin Lab Diagn, 1995 May-Jun, (3), 7 - 8
{An additional test in the identification of Enterobacteriaceae and some representatives of the genus Vibrio}; Bril'man IaE; An additional test: aerobic redox fermentation in semiliquid Hiss' medium with mannitol is recommended for the indication of Enterobacteriaceae, Vibrio, etc . The majority of mannite-fermenting enterobacteria change the color of the indicator in a thin upper layer of a column of semiliquid Hiss' medium in comparison with the bulk of medium after 20-24 h growth in it . Such changes of the indicator are never observed with Shigella, Salmonella, Vibrio bacteria of the studied strains, Yersinia, some cocci, etc., which may be considered as an additional differential diagnostic test at early stages of investigation with due consideration for other known signs . The aerobic redox test does not require additional quantities of nutrient media, reagents, or glassware.

Enferm Infecc Microbiol Clin, 1995 May, 13(5), 278 - 82
{Resistance to imipenem in Enterobacter aerogenes}; Miro E et al.; BACKGROUND: In June, 1993, an Enterobacter aerogenes strain was isolated in the Hospital de la Creu Roja from Hospitalet de Llobregat (Barcelona), which was resistant against all beta-lactams, including imipenem . Since is unusual in Enterobacter sp . to isolate imipenem resistant strains, we decided to study its resistance mechanism . METHODS: To study the E . aerogenes 174004/H resistance mechanism beta-lactamase isoelectrofocalization was performed together with the determination of kinetic constants in order to characterize the beta-lactamase, and a polyacrylamide gel electrophoresis in order to observe the profile . RESULTS: The strain of E . aerogenes 174004/H exhibits a chromosomic beta-lactamase with a pI higher than 9.2 and a decrease in an outer membrane protein of 42 kDa, probably a porine . CONCLUSIONS: E . aerogenes 174004/H resistance against imipenem is due to an hyperproduction of a chromosomic beta-lactamase with a pI higher than 9.2 and to a 42 kDa decrease of an outer membrane protein expression.

Am J Surg, 1995 May, 169(5A Suppl), 27S - 33S
Treatment of skin and soft-tissue infections; File TM Jr et al.; Bacterial infections of the skin range from mild pyodermas to life-threatening necrotizing infections . Pyodermas are most often due to Staphylococcus aureus or beta-hemolytic Streptococcus sp, whereas infections associated with skin ulcers of the extremities, infections following trauma or surgery, and histotoxic necrotizing infections may involve a large number of additional pathogens, including Enterobacteriaceae, Pseudomonas sp, enterococci, and anaerobes . Management of bacterial skin and soft-tissue infections includes appropriate surgical drainage or excision of infected tissue and antimicrobial therapy . The combination of piperacillin and the beta-lactamase inhibitor tazobactam is a newly released antimicrobial, which has excellent in vitro activity against the vast majority of pathogens involved in skin infections . Two multicenter studies recently evaluated the efficacy and safety of piperacillin/tazobactam in the therapy of skin and soft-tissue infections in hospitalized patients . Piperacillin/tazobactam was well tolerated and demonstrated high clinical efficacy for the treatment of these infections.

Am J Surg, 1995 May, 169(5A Suppl), 13S - 20S
Emergence and mechanisms of bacterial resistance in surgical infections; Neu HC; Antimicrobial resistance is commonplace among bacteria involved in surgical infections, including Staphylococcus aureus, enterococci, Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Bacteroides species . Resistance traits can be encoded on chromosomes or transmissible plasmids . The basic mechanisms of resistance are alteration of drug target, prevention of drug access to target, and drug inactivation . Examples include alteration of penicillin-binding proteins in resistance to penicillinase-resistant penicillins, ribosomal binding site protection in tetracycline resistance, and beta-lactamase destruction of beta-lactam compounds . Resistance due to the many types of beta-lactamases that have thus far been identified is wide-spread among common pathogens; use of beta-lactam/beta-lactamase inhibitor combinations has proved effective as one means of counteracting such resistance . Contending with resistance involves appropriate use of available antimicrobials, development of novel agents or modification of existing agents, and measures to forestall emergence and spread of resistant organisms.

Med Clin North Am, 1995 May, 79(3), 599 - 617
Intra-abdominal sepsis; Bartlett JG; This article addresses controversial issues in the field of intra-abdominal sepsis with particular attention to major changes in management that have evolved during the past decade . In the area of diagnostics, scanning techniques have revolutionized the ability to detect loculated collections, although many of these techniques are of limited value in the early stages of inflammation . The greatest debate concerns the relative merits of scanning techniques; the author's choice is CT scans with contrast, although ultrasonography is preferred in patients who cannot be transported and is probably preferred for pelvic infections . In the area of therapeutics, virtually all studies seem to show that single-drug treatment is as effective as dual combinations or triple-combination therapy that has been standard practice in the past with the proviso that the drug used has activity versus Enterobacteriaceae and B . fragilis . The role of enterococcus remains enigmatic; this organism was readily discounted as an important pathogen in the great majority of cases 10 years ago, but it has subsequently become a major nosocomial pathogen that now commands newfound respect . P . aeruginosa is also controversial, but most studies show that antipseudomonad treatment is not necessary in the empiric selection of drugs and may not be necessary even when P . aeruginosa is found at infected sites; the corollary to this is that aminoglycosides may no longer be required in the dual drug treatment regimens . There is increasing resistance by B . fragilis and some other species of Bacteroides to some of the drugs considered "standard" in the past, including clindamycin, cefoxitin, and cefotetan; nevertheless, it has been difficult to demonstrate that resistance of these organisms correlates with antibiotic failure . It was demonstrated 20 years ago that elective colon surgery must be accompanied by preoperative antibiotics, and erythromycin plus neomycin has evolved as the regimen of choice according to recommendations of authoritative sources for the past 20 years . Nevertheless, surveys of practicing surgeons indicate that most actually combine this oral preparation with parenteral agents as well . The final controversy concerns percutaneous drainage, which has now become a standard technique for dealing with intra-abdominal abscesses in 50% to 90% of cases . This controversy has sometimes been seen as a territorial battle between surgeons and radiologists, and most cases are clearly the prerogative of one discipline or the other, but many are in a gray zone in which clearly defined indications are not readily available.

J Bacteriol, 1995 May, 177(9), 2299 - 304
The fliA gene encoding sigma 28 in Yersinia enterocolitica; Iriarte M et al.; Yersinia enterocolitica is an enterobacterium responsible for gastrointestinal syndromes . Its pathogenicity depends on the presence of the 70-kb pYV plasmid, which directs Yop secretion . The Yop secretion machinery, consisting of the YscA-U and LcrD proteins, presents some structural similarity with the flagellum assembly machinery characterized in other bacteria . Flagellum assembly requires sigma 28, an alternative sigma factor . The region upstream of the lcrD gene resembles promoters recognized by sigma 28, suggesting that the similarity between Yop secretion and flagellum assembly could extend to their regulation . The chromosome of Y . enterocolitica also contains pathogenicity determinants such as myfA, which encodes the Myf antigen subunit . The promoter region of myfA also resembles promoters recognized by sigma 28 . In an attempt to clarify the role of sigma 28 in the expression of lcrD, myfA, and flagellar genes, we cloned, sequenced, and mutagenized the fliA gene encoding the sigma 28 homolog in Y . enterocolitica . As is the case in other bacteria, fliA was required for motility . However, it was involved neither in fibrilla synthesis nor in Yop secretion . The fliA mutant allowed us to monitor the role of motility in pathogenesis . At least in the mouse model, motility seemed not to be required for Y . enterocolitica pathogenesis.

Infect Immun, 1995 May, 63(5), 1840 - 7
The rpoS gene from Yersinia enterocolitica and its influence on expression of virulence factors; Iriarte M et al.; The chromosome of Yersinia enterocolitica encodes a heat-stable enterotoxin called Yst and a surface antigen called Myf, which closely resembles enterotoxin-associated fimbriae . Both factors could act in conjunction to produce diarrhea . Production of the enterotoxin is regulated by temperature, osmolarity, and pH and occurs only when bacteria reach the stationary phase . Myf production is regulated by temperature and pH and, as we show in this work, also occurs after the exponential growth phase . In an attempt to understand the late-phase expression of yst and myf, we cloned, sequenced, and mutagenized the gene encoding RpoS, an alternative sigma factor of the RNA polymerase involved in expression of stationary-phase genes in other enterobacteria . An intact rpoS gene was necessary for full expression of yst in the stationary phase but not for the expression of myf and of pYV-encoded virulence determinants.

J Infect, 1995 May, 30(3), 241 - 4
Aeromonas septicaemia in Hong Kong species distribution and associated disease; Duthie R et al.; During a 5-year study of 2211 patients with clinically significant positive blood cultures in Hong Kong . Aeromonas spp . were isolated in 40 cases . Among 26 episodes in which a single species was isolated . 17 (65.4%) were identified as Aeromonas hydrophila . 8 (30.8%) as A . sobria and one (3.8%) as A . caviae . There were 14 episodes with a mixture of species . Of these, nine (64.3%) were identified as A . hydrophila, two (14.3%) as A . sobria, and two (14.3%) as A . caviae . One (7.1%) was an infection with both A . sobria and A . hydrophila . These polymicrobial infections were usually combined with the presence of Enterobacteriaceae . Hepatobiliary disease was the underlying problem in 24 cases (60.0%) and malignant neoplasia in 14 (35.0%) cases . Most patients presented with fever and leucocytosis . The mortality rate for A . sobria septicaemia was not significantly different from the average rate for all septicaemias . A total of 30 isolates was available for sensitivity testing with 17 antibiotics . More than 86.0% were resistant to ampicillin, and the addition of the beta-lactamase inhibitor sulbactam did not restore its activity . All strains tested were sensitive to cefotaxime, ceftazidime, aztreonam, imipenem, norfloxacin and ciprofloxacin.

J Infect, 1995 May, 30(3), 223 - 6
An outbreak of Enterobacter cloacae associated with contamination of a blood gas machine; Lacey SL et al.; Over a 3-month period, five cases of Enterobacter cloacae bacteraemia occurred on our neonatal unit . In at least three of these, isolation of the organism coincided with clinical deterioration and evidence of sepsis . In one case, the same strain was isolated from an abscess on the neonate's forearm . The isolates had identical sensitivity patterns being resistant to all beta-lactams tested except imipenem . The extended time course of the infections made cross-infection an unlikely explanation . Moreover, close questioning of the staff and observation of their practices with regard to blood culture collection, failed to reveal any likely mechanism for pseudobacteraemia . On extensive investigation of the environment to try to identify a potential source of the organism, a strain of Enterobacter cloacae, was isolated from the probe of the blood gas machine and the probe cover . No other environmental samples were found to harbour the organism . Subsequent typing procedures showed the blood gas isolate to be indistinguishable from the clinical isolates . Five neonates were successfully treated with imipenem and gentamicin . The exact mechanism whereby these bacteraemias occurred remains obscure . In one case, the baby had positive blood cultures within 2 h of being on the unit and contamination of the blood culture bottle by the doctor taking the culture was suspected . Most of the episodes, however, appeared clinically to be genuine septicaemias . When vigorous infection control procedures were instituted to prevent staff acquisition of the organism from the machine, cases on the unit ceased.

Am J Vet Res, 1995 May, 56(5), 633 - 8
Clinical pharmacologic aspects of cefixime in dogs; Lavy E et al.; The minimal inhibitory concentration (MIC) of cefixime, a new third-generation orally administered caphalosporin, was determined for reference and clinical isolates from dogs . The MIC of the drug for all but 1 of the 18 Enterobacteriaceae isolates tested, 1 Pasteurella canis, 1 Rhodococcus equi, 1 Streptococcus canis, and 1 Streptococcus group G isolate, was less than 1.0 microgram/ml . The MIC for 9 Staphylococcus intermedius isolates ranged from 1.56 to 6.25 micrograms/ml and, for 8 Sta aureus isolates, the MIC values ranged from 1.56 to 12.5 micrograms/ml . Pseudomonas aeruginosa, Actinomyces sp, and a single Bordetella bronchiseptica isolate were considered resistant to cefixime . Cefixime was administered orally in 2 phases at a standard dosage of 5 mg/kg of body weight to clinically normal adult male and female dogs . In the first phase, the drug was given once as a capsule and once as a suspension . In the second phase, it was administered once per day for 6 consecutive days in capsule form . Serum drug concentration was determined by use of a microbiological assay, and the following kinetic values were estimated for each dog: area under the concentration-time curve, peak serum drug concentration (Cmax), time of Cmax, absorption half-life, and elimination half-life (t1/2el) . The kinetic profile of the drug in serum after oral administration of a single dose of cefixime was similar, with mean Cmax values of 3.36 and 4.76 micrograms/ml after treatment with the capsule and suspension, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemotherapy, 1995 May-Jun, 41(3), 193 - 9
Effect of beta-lactamase expression on susceptibility of local isolates of Enterobacter cloacae, Serratia marcescens and Pseudomonas aeruginosa to beta-lactam antibiotics; Ramadan MA et al.; During surveillance studies, a total of 66 strains of gram-negative bacilli (28 Enterobacter cloacae, 20 Serratia marcescens and 18 Pseudomonas aeruginosa) with a reduced susceptibility to third-generation cephalosporins, aztreonam and amikacin were isolated from documented infections . All isolates were highly susceptible to imipenem and sparfloxacin . beta-Lactamase activity was demonstrated in all isolates of E . cloacae and S . marcescens, and in 77% of P . aeruginosa isolates . Inducible beta-lactamase activity was detected in 80, 65 and 40% of E . cloacae, S . marcescens and P . aeruginosa isolates, respectively, when cefoxitin was used as an inducer . More inducible beta-lactamase producers were observed when imipenem was used as an inducer . Isolates of E . cloacae, and to a lesser extent S . marcescens, expressed a wide spectrum of beta-lactamase activities . There was a good correlation between baseline beta-lactamase activity and the respective MIC of ceftazidime, cefotaxime and ceftriaxone, and to a lesser extent aztreonam in E . cloacae and S . marcescens isolates . Only one isolate of E . cloacae demonstrated an extended beta-lactamase activity . The data suggest that the resistance of E . cloacae and S . marcescens isolates to beta-lactam antibiotics is largely dependent upon hyperproduction of beta-lactamase.

Chemotherapy, 1995 May-Jun, 41(3), 187 - 92
Transferable amikacin resistance in gram-negative bacterial isolates; Kallova J et al.; Seven amikacin-resistant strains of Enterobacteriaceae isolated in Slovakia and Germany were included in this study . The strains were also resistant in vitro to high levels of gentamicin, tobramycin, netilmicin and isepamicin . Phosphocellulose paper binding assays indicated that resistance to aminoglycosides was due to synthesis of aminoglycoside acetyltransferase AAC(6')-I a mechanism until now only identified in staphylococci and streptococci . This mechanism of aminoglycoside resistance has also been found in two isolates of Klebsiella pneumoniae from Germany . The substrate profile suggested that in addition to AAC(6')-I and APH(2"), several strains also produced AAC(3)-II . Aminoglycoside resistance was found to be transferable to Escherichia coli 3110 rifr in all isolates, and R plasmids of 36-45 MD were detected in donor and transconjugant strains . All isolated plasmids from transconjugants encoded resistance to aminoglycosides by genes encoding the enzymes AAC(6')-I and APH(2").

Antimicrob Agents Chemother, 1995 May, 39(5), 1178 - 81
Comparative antibacterial activity of L-695,256, a carbapenem active against methicillin-resistant staphylococci; Rylander M et al.; The activity of a new prototype carbapenem, L-695,256, against clinical isolates of gram-positive and gram-negative aerobes was studied in vitro by agar dilution . L-695,256 was highly active against methicillin-resistant and -susceptible isolates of staphylococci (MICs, 0.016 to 2 micrograms/ml) and against penicillin-resistant pneumococci (MICs, 0.016 to 0.064 micrograms/ml), irrespective of penicillin susceptibility . Activity against members of the family Enterobacteriaceae was less than that of imipenem, while Proteus mirabilis and Morganella morganii were more susceptible to L-695,256.

Antimicrob Agents Chemother, 1995 May, 39(5), 1030 - 7
In vitro and in vivo antibacterial activities of BO-2727, a new carbapenem; Asahi Y et al.; BO-2727, a new injectable carbapenem, was evaluated for its in vitro and in vivo antibacterial activities in comparison with those of biapenem, meropenem, imipenem, cefpirome, and ceftazidime . BO-2727 had activity comparable to that of imipenem against methicillin-susceptible staphylococci and streptococci, with MICs at which 90% of strains tested (MIC90s) are inhibited being equal to 0.5 microgram/ml or less . Against methicillin-resistant staphylococci, BO-2727 was the most active among the antibiotics tested, with MIC90s ranging from 4 to 8 micrograms/ml . BO-2727 was highly active against members of the family Enterobacteriaceae, Haemophilus influenzae, and Moraxella catarrhalis, with MIC90s ranging from 0.006 to 2 micrograms/ml . BO-2727 was also highly active against Pseudomonas aeruginosa (imipenem-susceptible strains), for which the MIC90 was 2 micrograms/ml, which was lower than those of imipenem, cefpirome, and ceftazidime and comparable to those of biapenem and meropenem . Differences in activity between BO-2727 and the other carbapenems against imipenem-resistant P . aeruginosa were particularly striking (MIC90, 8 micrograms/ml) . Furthermore, BO-2727 displayed a high degree of activity against many of the ceftazidime-, ciprofloxacin-, and/or gentamicin-resistant isolates of P . aeruginosa . The in vivo efficacy of BO-2727 against experimental septicemia caused by gram-positive and gram-negative bacteria, including methicillin-resistant Staphylococcus aureus and imipenem-resistant P . aeruginosa, reflected its potent in vitro activity and high levels in plasma.

Rev Clin Esp, 1995 May, 195(5), 304 - 7
{Cerebral abscess . Clinical review of 26 cases}; Estirado de Cabo E et al.; BACKGROUND . The introduction of new diagnostic and therapeutic techniques has changed the clinical attitude and consequences of brain abscesses (BA) . OBJECTIVE . To analyse clinical-radiological features, therapy, prognostic factors and evolution of BA in our institution . MATERIALS AND METHODS . Retrospective study of all clinical records of patients diagnosed with BA from 1982 to 1992 . RESULTS . Twenty-six patients with a mean age of 46.2 years were selected . The incidence was 2.6 patients/10,000 admission/year . Among 17 patients (65%) some extraprenchymatous infectious focus was found, which was located at the otorhynolaryngeal area in twelve patients . Mean duration of symptoms was 12.9 days, headache being the most common of them (69%) . With CT 18 patients had a single mass, eight patients multiple masses, and 21 patients a ring enhancement when the contrast material was introduced . The causative organism was recovered from 15 patients . The organism recovered more frequently were Streptococcus spp, Enterobacteriaceae and Staphylococcus aureus . Twenty patients (77%) underwent surgical therapy, which consisted in ablation (12) or drainage (8) . All patients received antibiotics for a mean of 37 days: the most frequent antibiotic combination used was penicillin+chloramphenicol . Six patients died (23%) and 7 remained with sequelae . Although statistically non-significant, the acute presentation was associated with a higher mortality rate, and the use of dexamethasone was associated with a lower mortality rate (p = 0.053 and 0.062, respectively) . CONCLUSIONS . BA is associated with a high mortality rate and a high sequelae rate despite appropriate diagnostic and therapeutic measures . ORL infection is the most frequent predisposing factor . The use of dexamethasone is not associated with a higher mortality rate.

J Clin Microbiol, 1995 May, 33(5), 1395 - 8
Evaluation of a new agar in Uricult-Trio for rapid detection of Escherichia coli in urine; Dalet F et al.; A new commercial agar (Uricult-Trio) with 8-hydroxyquinoline-beta-glucuronide was used to assess 2,536 uropathogens for beta-glucuronidase activity typical of Escherichia coli . Included in the study were 1,807 strains of the family Enterobacteriaceae, 284 strains of nonfermentative bacilli, 345 strains of gram-positive cocci, and 100 yeast strains . In identifying E . coli, the test agar gave a sensitivity of 95.5% and a specificity of 97.2% . Fifty E . coli isolates gave negative reactions; 31 non-E . coli strains produced black colonies characteristic of E . coli . No growth of gram-positive cocci and no false-positive reactions from yeasts were observed . The recovery rate for E . coli on this agar was at least 10% higher than that on blood agar.

J Clin Microbiol, 1995 May, 33(5), 1089 - 93
Genomic fingerprinting of Bartonella species by repetitive element PCR for distinguishing species and isolates; Rodriguez-Barradas MC et al.; Repetitive-element PCR (rep-PCR) with primers based on repetitive extragenic palindromic (REP) and enterobacterial repetitive intergenic consensus (ERIC) repeated DNA sequences was used for genomic finger-printing of Bartonella species . This technique was applied by using either extracted genomic DNA or preparations of whole bacterial cells directly . PCR fingerprints with either the REP-based primers (REP-PCR) or primers based on the ERIC repeat (ERIC-PCR) revealed species-specific band patterns for the various Bartonella isolates . DNA fingerprints obtained from rep-PCR of extracted genomic DNA or from preparations of whole cells yielded comparable patterns . ERIC-PCR banding patterns were less complex than those obtained by REP-PCR but allowed better discrimination between strains within species . By combining results of REP-PCR and ERIC-PCR, five different fingerprint profiles were identified among 17 isolates of Bartonella henselae, but only one profile was identified among the five isolates of Bartonella quintana . Other Bartonella species yielded distinct rep-PCR fingerprints . rep-PCR is a useful technique for identification of Bartonella organisms to the species level and offers the advantage of ease of performance, with only small quantities of cells needed for the whole-cell procedure . This technique also appears to be useful for subtyping B . henselae isolates.

J Clin Periodontol, 1995 May, 22(5), 391 - 6
Tetracycline-resistant micro-organisms recovered from patients with refractory periodontal disease; Olsvik B et al.; Tetracycline in combination with scaling and root planing is frequently used to treat refractory periodontal disease . This study examined tetracycline resistance in bacteria recovered from periodontal pockets of patients with refractory periodontitis . Bacterial isolates resistant to 10 micrograms/ml of tetracycline were isolated from plaque samples of 17 patients, of whom 6 had received tetracycline within 8 weeks prior to sampling . Minimal inhibitory concentrations (MICs) of tetracycline and minocycline were determined by agar dilution . In the 6 patients who had received tetracycline, a mean of 22.9% (+/- 38.2) of the total cultivable subgingival flora were resistant to tetracycline, compared with a mean of 7.2% (+/- 8.5) in the untreated group . Although various organisms were isolated, in most patients, the tetracycline-resistant organisms were dominated by Streptococcus spp . Overgrowth of Candida was found in one patient, and of Enterobacteriaceae in another patient, while small numbers of yeast or Staphylococcus spp . were isolated from the plaque samples of 9 others . 3 out of 4 patients who did not respond to tetracycline treatment had a variety of tetracycline-resistant anaerobic Gram-negative rods present . No correlation was found between increased proportions of tetracycline resistance in the whole bacterial sample and the presence of resistant periodontal pathogens.

Drugs, 1995 May, 49(5), 794 - 850
Fleroxacin . A review of its pharmacology and therapeutic efficacy in various infections; Balfour JA et al.; The fluoroquinolone antibacterial agent fleroxacin has a broad spectrum of in vitro activity which encompasses most Gram-negative species (particularly Enterobacteriaceae) and a number of Gram-positive organisms, including methicillin-sensitive staphylococci . It is available as oral and intravenous formulations . In clinical trials, fleroxacin has been evaluated in the treatment of uncomplicated urinary tract infections (single or multiple once-daily oral doses of 200 or 400mg), gonorrhoea and chancroid (single oral doses of 200 or 400mg), complicated urinary tract, nonpneumococcal lower respiratory tract and skin and soft tissue infections and typhoid fever (multiple once-daily oral or intravenous regimens, usually 400 mg/day), bacterial enteritis, and traveller's diarrhoea (single or multiple once-daily oral doses of 400mg) . Bacteriological cure rates were generally around 90% or higher in complicated and uncomplicated urinary tract infections, uncomplicated gonorrhoea (approximately 100%), pyelonephritis, bacterial enteritis and typhoid fever, and exceeded 80% in lower respiratory tract, and skin and soft tissue infections and chancroid . These cure rates were similar to, or better than, those achieved with standard comparator antibacterial agents such as penicillins, cephalosporins, cotrimoxazole, or other quinolones . Fleroxacin 400mg once daily also achieved bacteriological cure in approximately 80% of patients with bone and joint infections in preliminary studies . In Japanese studies using a lower dosage of 200 or 300 mg/day, fleroxacin was reported to be bacteriologically effective in a range of infections, including urinary tract and upper and lower respiratory tract infections . Fleroxacin has a relatively long elimination half-life, which allows once-daily administration, and it appears to have less propensity for interactions with other medications in comparison to many other fluoroquinolones . Its tolerability profile is typical of this class of compound, with adverse events mostly relating to the gastrointestinal tract, CNS, and skin and appendages (including phototoxicity) . Recent pooled tolerability data from worldwide clinical trials indicate that adverse events are reported by approximately 27% of patients receiving 200 mg/day orally or 400 mg/day orally or intravenously, and 17% of those receiving a single oral dose of 400mg . These exceed incidences reported for established fluoroquinolones, possibly indicating recent trends towards increased rates of reported adverse effects with these agents . However, in direct comparative studies with twice-daily fluoroquinolones, fleroxacin 400mg once daily produced a similar incidence of adverse effects to ofloxacin 800 mg/day and a slightly higher incidence than ciprofloxacin 1000 mg/day, while fleroxacin 200mg once daily produced a similar incidence to norfloxacin 800 mg/day.(ABSTRACT TRUNCATED AT 400 WORDS)

J Antimicrob Chemother, 1995 May, 35(5), 585 - 92
Control-related effective regrowth time and post-antibiotic effect of meropenem on gram-negative bacteria studied by bioluminescence and viable counts; Hanberger H et al.; A study was performed to compare viable counts and bioluminescence for determining control related effective regrowth time (CERT) and postantibiotic effect (PAE) on Gram-negative bacteria after two hours of exposure to meropenem . There was a good correlation between bioluminescence and viable counts in determining the cell numbers in growing cultures of Escherichia coli . CERT was defined as the time required for the resumption of logarithmic growth and an increase of 1 log10 to occur over the pre-exposure inoculum in the test culture minus corresponding time for the control culture . PAE and CERT were studied on reference strains of Enterobacter cloacae, E . coli, Klebsiella pneumoniae and Pseudomonas aeruginosa . At 4 x MIC of meropenem the CERTs of these four Gram-negative strains were 4.1, 4.9, 4.2, and 3.6 h, respectively, when assayed by bioluminescence . Corresponding CERTs using viable counts were 4.2, 5.0, 5.1 and 3.8 h, respectively . In contrast to this good agreement between the methods in assessing CERT, the corresponding PAEs were highly method dependent . At 4 x MIC of meropenem the PAEs on E . cloacae, E . coli, K . pneumoniae and P . aeruginosa were 3.9, 4.8, 4.7, and 3.5 h, respectively, when assayed by bioluminescene . However, the corresponding and simultaneously determined viable count PAEs were -0.4, 0.5, -0.1, and 0.7 h, respectively . The poor correlation between these methods in assessing the PAE is caused by greater initial decrease in viability compared with the less prominent initial change in cell density as measured by bioluminescence.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagn Microbiol Infect Dis, 1995 May-Jun, 22(1-2), 89 - 96
Interrelationship between pharmacokinetics and pharmacodynamics in determining dosage regimens for broad-spectrum cephalosporins; Craig WA; The broad-spectrum cephalosporins exhibit time-dependent bactericidal activity and produce prolonged postantibiotic effects only with staphylococci . The duration of time that serum levels exceed the minimum inhibitory concentration (MIC) is the important pharmacodynamic parameter correlating with efficacy for these drugs . Maximal efficacy for cephalosporins in several animal infection models is approached when serum levels are above the MIC for 60%-70% of the dosing interval for Enterobacteriaceae and streptococci and for 40%-50% of the dosing interval for Staphylococcus aureus . Based on MIC90 values of 0.5 microgram/ml for enteric bacilli and 4 micrograms/ml for S . aureus, these time above MIC goals can be easily met in infected and/or elderly patients following 1-2 g of cefotaxime at 12-h intervals . Full knowledge of the interrelationships between pharmacokinetics and pharmacodynamics is important for determining effective dosage regimens for the broad-spectrum cephalosporins.

Diagn Microbiol Infect Dis, 1995 May-Jun, 22(1-2), 71 - 6
Role of pharmacokinetics and pharmacodynamics in the design of dosage schedules for 12-h cefotaxime alone and in combination with other antibiotics; Nix DE et al.; Pharmacodynamic principles have provided important tools to evaluate and compare antimicrobial agents, and well as to guide dosing . For beta-lactams, time above the minimum inhibitory concentration (MIC) has surfaced as the most important factor . However, the area under the inhibitory serum concentration time-curve (AUIC) may be superior when appropriate dosing intervals are selected . Although the target time over the MIC is unclear in humans even when concentrations remain continuously above the MIC, a higher AUIC predicts better clinical outcome up to a maximum . This article provides a pharmacodynamic assessment of 1- and 2-g doses of cefotaxime every 12 h . AUIC24 values and published MIC values for common pathogens (grouped into four groups based on MIC90) were used to predict organisms suitable for treatment with every-12-h regimes . Cefotaxime was inadequate for group 4 organisms including: Pseudomonas aeruginosa, Acienetobacter sp., and Enterococcus sp . Organisms such as Enterobacter cloacae, Serratia marcescens, Staphylococcus aureus, and B . fragilis may be suboptimally treated with cefotaxime every 12 h . Cefotaxime in doses of 1-2 g every 12 h should be useful in patients with normal renal function infected with organisms having MICs < 0.5 microgram/ml . This regimen should obtain AUIC24 values > 125 and ensure adequate time above the MIC . In patients with impaired renal function, because of a longer half-life and higher area under the curve, pathogens with MIC values in the 0.5-2 micrograms/ml range may be treated with cefotaxime every 12 h while maintaining AUICs > 125 . Data are also presented for cefotaxime 2 g every 8 h alone and in combination with ofloxacin.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagn Microbiol Infect Dis, 1995 May-Jun, 22(1-2), 57 - 69
Pharmacodynamic (kinetic) considerations in the treatment of moderately severe infections with cefotaxime; Turnidge JD; Information about the pharmacodynamics of beta-lactams has accumulated rapidly over the last 20 years, and their application to cefotaxime are discussed in this review . Application of pharmacodynamics requires an integration of the pharmacokinetic and in vitro properties of the agent . Cefotaxime is similar to other beta-lactams in that it has little concentration-dependent killing and produces no postantibiotic effect against Gram-negative bacteria . However, it has a microbiologically active metabolite, deascetylcefotaxime, which can show synergy, partial synergy, or an additive effect in combination with the parent drug . More than any other technique, animal models have been able to elucidate the pharmacokinetic parameters that predict efficacy in vivo . They have shown that for beta-lactams it is the time that levels exceed the minimum inhibitory concentration (MIC) that is the most important determinant of efficacy . For bacteria to have no postantibiotic effect, plasma levels need to exceed the MIC for the whole of the dosing interval to achieve maximum killing at the site of infection . When applying these concepts as the most stringent criteria for efficacy using pharmacokinetic values from young, healthy volunteers, it can be shown that organisms with MICs of < or = 0.03 microgram/ml for a 1-g dose and 0.06 microgram/ml for a 2-g dose to achieve optimum efficacy with 12-h dosing of cefotaxime . However, two clinical studies have demonstrated trough levels much greater than would be predicted from these pharmacokinetic values, as a result of the effects of decreased renal function accompanying sepsis and older age . These studies showed that organisms with MICs < or = 1 microgram/ml for a 1-g dose or 2 micrograms/ml for a 2-g 12-h dose were covered for the whole of the dosing interval . Thus, all strains of Enterobacteriaceae and pathogenic Neisseria spp . that lack resistance mechanisms to third-generation cephalosporins would be covered using 12-h dosing schedules.

Diagn Microbiol Infect Dis, 1995 May-Jun, 22(1-2), 129 - 34
Selection of cephalosporins for hospital formularies; Wilson WR; Because of the large number of cephalosporins available for use, and for economic reasons, most hospitals have restricted the number of cephalosporins for inclusion on hospital formularies . No more than one first-generation oral and parenteral cephalosporin is necessary . The second- and third-generation oral cephalosporins are more active in vitro against Haemophilus influenzae and Enterobacteriaceae, and the selection of one of these drugs should be based primarily on acquisition cost . There is usually minimal, if any, need for a second-generation parenteral cephalosporin on hospital formularies . The choice of a single third-generation parenteral cephalosporin should be made primarily on the cost of equivalent daily dosages . A single antipseudomonal cephalosporin should be included in the hospital formulary, and the selection should be based on cost and availability.

Eur J Clin Microbiol Infect Dis, 1995 May, 14(5), 383 - 90
Pharmacodynamic effects of meropenem on gram-negative bacteria; Hanberger H et al.; The in vitro initial killing and post-antibiotic effect (PAE) of meropenem on five gram-negative reference strains were evaluated by bioluminescence assay of bacterial adenosine triphosphate (ATP) and viable count . Morphology studies were performed in parallel . Meropenem showed concentration-dependent long (2-5 h) PAEs on Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Serratia marcescens when assayed by bioluminescence and induced spheroplasts at almost all concentrations . The bioluminescence PAEs reached a maximum response at 4 x MIC . These PAEs of meropenem on Escherichia coli, Klebsiella pneumoniae and Serratia marcescens were longer than corresponding PAEs of imipenem shown in previous studies . The higher affinity of meropenem than imipenem for PBP 3 might explain the longer PAEs obtained with meropenem . However, there was only a very short PAE, no PAE or even a negative PAE when viable count was used as the initial value for the PAE calculation . A strong initial decrease in viability but a less pronounced change in intracellular ATP was registered . Since this initial change in cell numbers is the initial value for the PAE calculation, the length of PAE was highly method dependent . In summary, a strong initial killing and no PAE were shown using viable count as the initial value for the PAE calculation, but a weak initial killing and long PAEs were shown when bioluminescence was used throughout the experiments.

Bratisl Lek Listy, 1995 May, 96(5), 241 - 4
{Bacterial virulence factors and their role in the pathogenesis of pyogenic infections of the abdominal cavity and mediastinum}; Kotulova D et al.; Purulent peritonitis are caused predominantly by anaerobic bacteria which come from physiological intestinal flora . Mediastinitis is caused amidst other etiologic factors also by bacteria inhabiting the oropharyngeal region, as well as microorganisms causing diseases localized in the proximity of mediastinum . Anaerobic sporulating bacteria both Gram positive and negative cause often miscellaneous infections due to Staphylococcus aureus, Enterobacteriacae, Streptococcus, Enterococcus . It involves a group of bacteria which are able to produce a fibrin network in their proximity, to resist phagocytosis by their structures, to distruct the components of the complement system and immunoglobulins, to impair membranes of cells which leads by means of their factors of virulence to formation of defectuous immunity . Microbiological examination requires the material to be sent for anaerobic cultivation and the antimicrobial therapy must take into account its polymicrobic etiology . (Ref . 23.)

APMIS, 1995 May, 103(5), 388 - 94
Immunogenicity expressed in patients with bacteraemia of an epitope shared by enterobacterial and neisserial porin proteins; Henriksen AZ et al.; A monoclonal antibody (MAb) against an epitope (Po I) on an Escherichia coli O55 porin protein has shown broad cross-reactivity with other Enterobacteriaceae and with both pathogenic and non-pathogenic Neisseriaceae . In this study, we have measured antibody levels against the Po I site in patients with bacteraemia in order to examine the immunogenicity of the Po I domain in humans . A MAb-based competition ELISA (cELISA) was used . Only 20% of healthy controls had detectable levels of anti-Po I antibodies in serum . Of patients bacteraemic with enterobacteria (n = 45), 11% and 58% showed elevated antibody levels compared to healthy controls with the first and second serum specimens, respectively, and 73% of these patients showed > or = 10% increase in the antibody levels . Of patients bacteraemic with N . meningitidis (n = 20), only 30% showed > or = 10% increase in the antibody levels when paired serum specimens were tested . Levels of competing antibodies were similar in the cELISA with N . meningitidis (B: 15: P1, 7, 16) OM coat or E . coli O55 OM coat . The results demonstrated that the highly conserved porin protein domain Po I expressed immunogenicity in humans when present in bacteria which caused bacteraemia . This finding represents a challenge in further investigations on the immunobiological role of the cross-reacting antibodies.

Arch Microbiol, 1995 May, 163(5), 357 - 65
Escherichia coli and other species of the Enterobacteriaceae encode a protein similar to the family of Mip-like FK506-binding proteins; Horne SM et al.; A newly identified gene in Escherichia coli, fkpA, encodes a protein with extensive similarity to the macrophage infectivity potentiator (Mip) proteins of Legionella pneumophila and Chlamydia trachomatis . The FkpA protein may be a new member of the family of FK506-binding proteins (FKBPs) because its carboxyl domain includes a sequence that matches the consensus FK506-binding motif in 40 of 48 positions, including those amino acids at the active site that form hydrogen bonds with the drug FK506 . The amino acid sequence of the 29 kDa FkpA protein is 30-35% identical to the Mip proteins of L . pneumophila, L . micdadei, and C . trachomatis . Of the 270 amino acids of FkpA, 113 (42%) are identical to the sequence of one or another of these Mip proteins . Overexpression of FkpA or deletion of fkpA from the E . coli chromosome had no detrimental effect on bacterial growth, indicating that fkpA is not an essential gene . Hybridization of fkpA-specific DNA probes to genomic blots revealed that similar genes exist in several representatives of the Enterobacteriaceae . Thus, mip-like genes are not found exclusively in bacteria having a predominately intracellular life style, but instead appear to be a new FKBP subfamily that is a common constituent of many bacteria.

Gene, 1995 Apr 14, 156(1), 37 - 42
IS1222: analysis and distribution of a new insertion sequence in Enterobacter agglomerans 339; Steibl HD et al.; With a length of 1221 bp and 44-bp inverted repeats with ten mismatches, IS1222 was identified as an endogenous insertion sequence in Enterobacter agglomerans 339 . In this host strain, four copies were located, three on the nif plasmid pEA9 and one at the chromosome . Sequence analysis showed two consecutive open reading frames, orfA and orfB, encoding putative polypeptides of 87 and 276 amino acids . In-between both reading frames, a potential frameshift window of the homonucleotide type was postulated, followed by a pseudoknot structure and a ribosome-binding site . Based on significant homology at the sequence level and similarity of the features discussed, IS1222 was placed among the group of IS3 elements with IS407, IS476 and ISR1 being the most closely related IS . Hybridization experiments suggest that the distribution of IS1222 is limited to a group of related bacterial strains among Enterobacteriaceae.

J Med Chem, 1995 Apr 14, 38(8), 1380 - 5
Cephalosporin derivatives of doxorubicin as prodrugs for activation by monoclonal antibody-beta-lactamase conjugates; Vrudhula VM et al.; The synthesis of a series of cephalosporin doxorubicin derivatives that differ with respect to the substituent at position 7 of the cephem nucleus is described . These compounds are designed as prodrugs of doxorubicin for activation by monoclonal antibody-beta-lactamase conjugates . The key step in the synthesis of this series of compounds involves the use of the phenylacetamido group as an enzymatically removable protecting group for the 7-amino group on the cephem . In vitro cytotoxicity assays with H2981 lung adenocarcinoma cells revealed that cephalosporin doxorubicin derivatives were all less toxic than the released drug . Prodrugs containing negatively charged groups in the side chain, such as the delta-carboxybutanamido derivative 4 and the alpha-sulfophenylacetyl derivative 5, displayed the least cytotoxic activity and were 46- and 26-fold less toxic than doxorubicin, respectively . The efficiency of activation of all the prodrugs was evaluated in cytotoxicity assays on H2981 cells with the beta-lactamases from Enterobacter cloacae P99, Escherichia coli TEM-1, and Bacillus cereus (type II) . In general, the E . cloacae enzyme was found to most rapidly activate the majority of these prodrugs . Phenylacetamido prodrug 2 and delta-carboxybutanamido prodrug 4 were both activated in an immunospecific manner by L6-E . cloacae beta-lactamase, a monoclonal antibody conjugate that binds to receptors on H2981 lung adenocarcinoma cells.

J Bacteriol, 1995 Apr, 177(7), 1911 - 4
Cloning and nucleotide sequence of the gene coding for the major 25-kilodalton outer membrane protein of Brucella abortus; de Wergifosse P et al.; The cloning and sequencing of the Brucella abortus major 25-kDa outer membrane protein (OMP) is reported . The 25-kDa (group 3) OMP has been proposed, on the basis of amino acid composition, to be the counterpart of OmpA (D . R . Verstraete, M . T . Creasy, N . T . Caveney, C . L . Baldwin, M . W . Blab, and A . J . Winter, Infect . Immun . 35:979-989, 1982) . However, the amino acid sequence predicted from the cloned B . abortus gene did not reveal significant homology with either OmpA sequences from different members of the family Enterobacteriaceae or other known protein sequences.

J Bacteriol, 1995 Apr, 177(7), 1872 - 8
The occurrence of duplicate lysyl-tRNA synthetase gene homologs in Escherichia coli and other procaryotes; Saluta MV et al.; The lysyl-tRNA synthetase (LysRS) system of Escherichia coli K-12 consists of two genes, lysS, which is constitutive, and lysU, which is inducible . It is of importance to know how extensively the two-gene LysRS system is distributed in procaryotes, in particular, among members of the family Enterobacteriaceae . To this end, the enterics E . coli K-12 and B; E . coli reference collection (ECOR) isolates EC2, EC49, EC65, and EC68; Shigella flexneri; Salmonella typhimurium; Klebsiella pneumoniae; Enterobacter aerogenes; Serratia marcescens; and Proteus vulgaris and the nonenterics Pseudomonas aeruginosa and Bacillus megaterium were grown in AC broth to a pH of 5.5 or less or cultured in SABO medium at pH 5.0 . These growth conditions are known to induce LysRS activity (LysU synthesis) in E . coli K-12 . Significant induction of LysRS activity (twofold or better) was observed in the E . coli strains, the ECOR isolates, S . flexneri, K . pneumoniae, and E . aerogenes . To demonstrate an association between LysRS induction and two distinct LysRS genes, Southern blotting was performed with a probe representing an 871-bp fragment amplified from an internal portion of the coding region of the lysU gene . In initial experiments, chromosomal DNA from E . coli K-12 strain MC4100 (lysS+ lysU+) was double digested with either BamHI and HindIII or BamHI and SalI, producing hybridizable fragments of 12.4 and 4.2 kb and 6.6 and 5.2 kb, respectively . Subjecting the chromosomal DNA of E . coli K-12 strain GNB10181 (lysS+ delta lysU) to the same regimen established that the larger fragment from each digestion contained the lysU gene . The results of Southern blot analysis of the other bacterial strains revealed that two hybridizable fragments were obtained from all of the E . coli and ECOR collection strains examined and S . flexneri, K . pneumoniae, and E . aerogenes . Only one lysU homolog was found with S . typhimurium and S . marcescens, and none was obtained with P . vulgaris . A single hybridizable band was found with both P . aeruginose and B, megaterium . These results show that the dual-gene LysRS system is not confined to E . coli K-12 and indicate that it may have first appeared in the genus Enterobacter.

Anaesth Intensive Care, 1995 Apr, 23(2), 168 - 74
Is there a role for selective decontamination of the digestive tract in primarily infected patients in the ICU?
Hammond JM, Potgieter PD.
The role of selective decontamination of the digestive tract (SDD) for the prevention of nosocomial infection in critically ill patients remains controversial, and the efficacy of this technique in patients who are already infected on presentation to the intensive care unit has not previously been assessed . We performed a double-blind randomized placebo controlled trial of SDD (parenteral cefotaxime, six-hourly oral and enteral polymyxin E, tobramycin, and amphotericin B vs placebo) for all infected patients presenting to the ICU requiring mechanical ventilation for more than 48 hours and ICU stay of more than 5 days . Daily clinical and microbiological monitoring for secondary infection was undertaken until hospital discharge . In all, 59 selective decontamination and 76 placebo fully comparable patients fulfilled criteria for enrollment and analysis (APACHE II 15.2 vs 15.1) . The number of patients receiving SDD who developed nosocomial infections was significantly reduced (P = 0.048), and there were no infections caused by the enterobacteriaceae or Candida spp in this group . No difference in ICU (17.5 vs 18.8 days) or hospital stay (32.7 vs 34.2 days) or mortality (17% vs 22.3%) was shown . Critically ill, primarily infected patients are protected from nosocomial infection by the use of SDD.

J Clin Microbiol, 1995 Apr, 33(4), 912 - 4
Epidemiological typing of Stenotrophomonas (Xanthomonas) maltophilia by PCR; Chatelut M et al.; We used two PCR methods for epidemiological typing of Stenotrophomonas (Xanthomonas) maltophilia with either arbitrary primers (random amplified polymorphic DNA) or enterobacterial repetitive intergenic consensus sequences as primers (ERIC-PCR) . The analysis was performed with 38 isolates of S . maltophilia, comprising 9 nosocomial isolates from a burn unit, 20 other clinical isolates epidemiologically unrelated, and 9 isolates from one cystic fibrosis patient . Both methods indicated that all of the nosocomial episodes were independent . In contrast, the nine isolates from the cystic fibrosis patient were assigned to very closely related profiles, especially by ERIC-PCR . We conclude that random amplified polymorphic DNA and ERIC-PCR have comparable reproducible and discriminatory powers for epidemiological typing of S . maltophilia, but ERIC-PCR profiles can be more easily evaluated.

J Clin Microbiol, 1995 Apr, 33(4), 1025 - 7
Evaluation of CPS ID2 medium for detection of urinary tract bacterial isolates in specimens from a rehabilitation center; Mazoyer MA et al.; CPS ID2 medium (bioMerieux) enables the presumptive identification of Escherichia coli and enterococci as well as the detection of indologenous or nonindologenous Proteeae and bacteria belonging to the Klebsiella, Enterobacter, and Serratia group with a specificity ranging from 98 to 100% . When the cultures were polymicrobial, the sensitivity varied from 70 to 97%, and the sensitivity varied from 97 to 100% when they were monomicrobial.

Drugs, 1995 Apr, 49(4), 577 - 617
Ceftazidime . An update of its antibacterial activity, pharmacokinetic properties and therapeutic efficacy; Rains CP et al.; Ceftazidime is a third generation cephalosporin antibacterial agent which, since its introduction in the early 1980s, has retained a broad spectrum of in vitro antimicrobial activity and clinical utility in serious infections . However, increasing resistance to ceftazidime and other third generation cephalosporins, particularly among Enterobacteriaceae, due to the emergence of plasmid-mediated extended spectrum beta-lactamases and the class I chromosomally mediated beta-lactamases, is of concern . There is now a wealth of information on the pharmacokinetics of the drug . enabling ceftazidime to be used predictably, and with a low potential for adverse effects, in a diversity of patient populations . Overall, ceftazidime remains an effective agent for the treatment of serious infection, particularly those due to major nosocomial pathogens, and respiratory infections in patients with cystic fibrosis . Ceftazidime-containing regimens also remain an important option for the empirical therapy of febrile episodes in neutropenic patients . The tolerability profile of ceftazidime makes the drug a useful option in seriously ill patients who are at risk of developing adverse events with other antibacterial agents . Although patterns of bacterial resistance have changed in the ensuing years since its introduction, judicious use of this important agent will help maintain its present clinical utility.

Jpn J Antibiot, 1995 Apr, 48(4), 529 - 47
{Antimicrobial activities of sulbactam/ampicillin against clinically isolated microbial strains}; Deguchi K et al.; Antimicrobial activities were examined for sulbactam/ampicillin (SBT/ABPC) against clinically isolated microbial strains in 1987, 1990, 1994 . Besides, the beta-lactamase productivity and MICs of these strains were measured, and the following conclusions were obtained . 1 . The ratio of beta-lactamase producing strains were 90% of methicillin (DMPPC)-susceptible Staphylococcus aureus subsp . aureus (MSSA), about 80% of DMPPC-resistant S . aureus (MRSA), 100% of Escherichia coli, Klebsiella pneumoniae subsp . pneumoniae and Proteus mirabilis, 95% of Moraxella subgenus Branhamella catarrhalis and 15-20% of Haemophilus influenzae . Several kinds of beta-lactamase productivity were observed . 2 . Antimicrobial activities of SBT/ABPC against beta-lactamase producing strains of MSSA, M . (B.) catarrhalis, H . influenzae, and almost all of Enterobacteriaceae were stronger than those of ampicillin (ABPC) and piperacillin (PIPC), but antimicrobial activities of SBT/ABPC were weak against MRSA and cephems (CEPs)-resistant strains detected in some of Enterobacteriaceae . 3 . It appeared that benzylpenicillin (PCG)-insensitive Streptococcus pneumoniae (PISP) or PCG-resistant S . pneumoniae (PRSP) and CEPs-resistant Escherichia coli increased year by year . 4 . Antimicrobial activities of SBT/ABPC were strong against Streptococcus pyogenes, S . pneumoniae, M . (B.) catarrhalis and H . influenzae including beta-lactamase producing strains . Additionally, beta-lactamase inhibiting effect of SBT was observed against beta-lactamase produced by S . aureus and K . pneumoniae which demonstrate indirect pathogenicity . Thus, SBT/ABPC is an injectable antibiotic that is expected to demonstrate clinical usefulness, especially as the first line drug for the respiratory tract infections that are community-acquired.

Bol Oficina Sanit Panam, 1995 Apr, 118(4), 302 - 6
{Bactericidal effect of hydrated lime in aqueous solution}; Munoz Ruiz C et al.; This study determined the bactericidal effect of the supernatants of saturated solutions of common lime and of micronized calcium hydroxide (Ca(OH)2) (1500 mg/L), which was used as a control, compared with disinfectants made of solutions of 0.33% colloidal silver (0.0016 mg/L), toluene sulfachloramine (41 mg/L) with sodium bicarbonate (9 mg/L), and sodium hypochlorite (5 mg/L) . The test involved four strains of Vibrio cholerae 01, V . parahaemolyticus, Escherichia coli, Salmonella typhimurium, Shigella flexneri, Sh . sonnei, and Sa . enterititidis . These bacteria were inoculated into the bactericidal substances listed above and, after different incubation times, the number of surviving bacteria was determined in vitro by using a counting plate . The results were expressed in colony-forming units (CFU) . An in situ estimate was made of the amount of V . cholerae on 35 strawberries and 35 radishes (having a weight of about 10 g per unit) after they were washed under a flow of potable water, submerged in the supernatant of the saturated lime solution (1.5 g/L), or both . The greatest bactericidal effect was obtained against V . cholerae 01 and was observed in 3 minutes . Other enterobacteria were resistant to the effect for up to 30 minutes.

Biosci Biotechnol Biochem, 1995 Apr, 59(4), 632 - 7
Purification and characterization of extracellular alginate lyase from Enterobacter cloacae M-1; Nibu Y et al.; An alginate lyase from the culture supernatant of Enterobacter cloacae M-1 was purified by ammonium sulfate precipitation, cation-exchange chromatography (SP-Toyopearl), and gel filtration (Ultrogel AcA44) . The final preparation thus obtained showed a single band on SDS-PAGE . The purified enzyme had the molecular weight of 38,000 and 32,000 by SDS-PAGE and gel filtration, respectively . The pI of the enzyme was 8.9 . The optimum pH and temperature for the enzyme reaction were around 7.8 and 30 degrees C, respectively . The enzyme was unstable on heating . EDTA completely inhibited the enzyme activity, but the activity was completely restored by the treatment with CaCl2 . The enzyme was specific for poly-guluronate and produced several kinds of unsaturated oligomers from the gluluronate . This suggested that the enzyme could be classified as an endo poly-guluronate lyase.

Appl Environ Microbiol, 1995 Apr, 61(4), 1226 - 31
Reverse transcription PCR to detect enteroviruses in surface water; Gilgen M et al.; We have developed a simple, fast, and efficient procedure to detect enteroviruses in water samples . Aliquots of water are subjected to two-step filtration, with the second filter containing a positively charged nylon membrane that holds back virus particles . Viruses thus adsorbed are directly lysed, and RNA is isolated by hybridization to specific oligonucleotides bound to magnetic beads . The solution used contains guanidine thiocyanate, which lyses virus particles, inactivates enzymes, e.g., RNases, allows mild hybridization conditions, and does not influence biotin-streptavidin interaction on magnetic beads . Detection and specific identification are accomplished by reverse transcription PCR of the highly conserved noncoding region at the 5' end of virus RNA combined with Southern hybridization . The system was tested with tap water artificially spiked with poliovirus vaccine and yielded a detection limit of 20 50% tissue culture infective doses per liter . We used the same procedure to investigate the water quality of surface water at public beaches by rivers and lakes . Of 40 samples tested, 7 were positive for enteroviruses . A comparison with enterobacterial contamination determined by PCR and classical microbiological methods in parallel showed that enteroviruses were found only in samples also positive for Escherichia coli . In conclusion, this procedure can easily be adapted to test large water samples and is simple enough to be used for routine determinations of water quality in terms of virus contamination.

J Bacteriol, 1995 Apr, 177(8), 2050 - 6
An Escherichia coli chromosomal ars operon homolog is functional in arsenic detoxification and is conserved in gram-negative bacteria; Diorio C et al.; Arsenic is a known toxic metalloid, whose trivalent and pentavalent ions can inhibit many biochemical processes . Operons which encode arsenic resistance have been found in multicopy plasmids from both gram-positive and gram-negative bacteria . The resistance mechanism is encoded from a single operon which typically consists of an arsenite ion-inducible repressor that regulates expression of an arsenate reductase and inner membrane-associated arsenite export system . Using a lacZ transcriptional gene fusion library, we have identified an Escherichia coli operon whose expression is induced by cellular exposure to sodium arsenite at concentrations as low as 5 micrograms/liter . This chromosomal operon was cloned, sequenced, and found to consist of three cistrons which we named arsR, arsB, and arsC because of their strong homology to plasmid-borne ars operons . Mutants in the chromosomal ars operon were found to be approximately 10- to 100-fold more sensitive to sodium arsenate and arsenite exposure than wild-type E . coli, while wild-type E . coli that contained the operon cloned on a ColE1-based plasmid was found to be at least 2- to 10-fold more resistant to sodium arsenate and arsenite . Moreover, Southern blotting and high-stringency hybridization of this operon with chromosomal DNAs from a number of bacterial species showed homologous sequences among members of the family Enterobacteriaceae, and hybridization was detectable even in Pseudomonas aeruginosa . These results suggest that the chromosomal ars operon may be the evolutionary precursor of the plasmid-borne operon, as a multicopy plasmid location would allow the operon to be amplified and its products to confer increased resistance to this toxic metalloid.

Am J Respir Crit Care Med, 1995 Apr, 151(4), 1063 - 7
Gastric flora in chronically mechanically ventilated patients . Relationship to upper and lower airway colonization; Palmer LB et al.; The oropharynx, stomach, and trachea are all potential reservoirs for gram-negative organisms in mechanically ventilated patients . The pathogenic importance of each site in respiratory infection may differ between mechanically ventilated patients who are medically stable and the critically ill, and these differences may be important in understanding the pathogenesis of nosocomial infection . We prospectively studied seven patients requiring chronic ventilatory assistance who were otherwise medically stable to determine the pattern of gram-negative colonization of these three sites . Serial weekly oropharyngeal, gastric, and tracheal cultures were taken over a 6-mo period in our Respiratory Care Unit for chronically ventilator-dependent patients . Pseudomonas aeruginosa (PA) was present more frequently and persistently in the trachea than the oropharynx and stomach (p < 0.01) and members of the family Enterobacteriaceae (Ent . species) were also observed more commonly in the trachea than the oropharynx (p < 0.01) . PA was seen in 6.7% of gastric specimens whereas Ent . species were found in 40% of gastric specimens . Six identical strains from a total of 53 gastric isolates and 128 oropharyngeal isolates were cultured coincidentally from these two sites . Coincidental isolation of 11 strains was observed in 177 tracheal isolates and 53 gastric samples . Documented transfers from stomach to oropharynx ascertained by sequential isolation occurred in one of 118 cultures and transfer from stomach to trachea occurred in three of 134 cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

J Hosp Infect, 1995 Apr, 29(4), 305 - 9
Postoperative wound infections; Yalcin AN et al.; A prospective study of postoperative wound infection was carried out over a two year period in Cumhuriyet University Medicine Faculty Hospital in Sivas, Turkey . Examination of wounds, with cultures of all suspicious wounds using standard bacteriological methods was performed . Of a total of 4146 surgical wounds, 188 (4.53%), became infected . High infection rates were noted after colon resection (32.1%), gastric and oesophageal operations (21.1%), cholesystectomy (17.2%), and splenectomy (10.2%) . Low infection rates were noted after thyroidectomy, mastectomy, caesarean section and abdominal hysterectomy . The commonest causative organisms were coagulase-negative staphylococci 21.7%, Staphylococcus aureus 19.7%, Escherichia coli 19.7%, Enterobacter spp . 17.6%, and Pseudomonas spp . 10.7%.

Antibiot Khimioter, 1995 Apr, 40(4), 34 - 6
{Antibacterial activity and toxicity of a new nitrofuran}; Terekhov VI et al.; A new nitrofuran, N-(5-nitrofurfurilidene)-5-nitrofuran-2-(N'-acetyl)carboxamidra zone designated as PAP-49 was synthesized . With the method of two-fold serial dilutions in the Hottinger's broth it was demonstrated that by its antimicrobial activity against cocci and enterobacteria PAP-49 was not inferior and in some cases it was even superior to such antibiotics and chemical drugs as benzylpenicillin, streptomycin, tetracycline, chloramphenicol, erythromycin, gentamicin, nitoxolin and furazolidone . The further study of the antibacterial properties of the new nitrofuran with the use of 101 strains of 16 bacterial species showed that its MICs for gram positive and gram negative bacteria were 0.03-3.13 and 0.78-125.0 micrograms/ml respectively . Combination of PAP-49 in the subbacteriostatic concentrations with other antimicrobial agents provided a 2-8-fold increase in the antimicrobial effect . The highest synergism was observed when nitrofuran was used in combination with aminoglycosides, benzylpenicillin or levomycetin . The primary screening revealed that PAP-49 belongs to the group of low toxic substances . Its LD50 after the oral administration to albino mice was 4631.9 mg/kg . The compound did not practically cumulate in the animal organism.

Mol Microbiol, 1995 Apr, 16(1), 145 - 55
UreR activates transcription at multiple promoters within the plasmid-encoded urease locus of the Enterobacteriaceae; D'Orazio SE et al.; Urease activity is produced by members of the family Enterobacteriaceae that contain the plasmid-encoded urease locus only when urea is present in the growth medium . The plasmid-encoded urease locus contains seven tandem urease structural and accessory genes (ureDABCEFG) . Previously we showed that transcription of the first gene in this cluster, ureD, is initiated at a urea-dependent promoter (ureDp) . Expression from ureDp requires the product of ureR, which is transcribed divergently from the plasmid-encoded ureDABCEFG . From DNA sequence analysis, UreR is predicted to be a 34 kDa protein with identity to the AraC family of transcriptional activators . In this report we demonstrate that there are two additional urea and UreR-dependent promoters within the plasmid-encoded urease locus: ureRp and ureGp . A low-level constitutive promoter was also identified upstream of ureE (ureEp) . Three major mRNA transcripts were induced when urea was present in the growth medium: a transcript containing ureDABCEF, a transcript corresponding to ureG, and a transcript corresponding to ureR . These results indicate that expression of each of the plasmid-encoded urease genes is transcriptionally regulated in response to urea and suggest that there is autogenous regulation of ureR . Therefore UreR is one of three AraC family members described thus far that are positively auto-regulated.

FEMS Immunol Med Microbiol, 1995 Apr, 11(2), 81 - 6
Mouse protection induced by Pseudomonas aeruginosa PAC1R and its defective mutants, Salmonella minnesota Re-mutant and Escherichia coli O14; Stanislavsky ES et al.; Pseudomonas aeruginosa PAC1R and its defective mutants (acetone-killed bacteria), Salmonella minnesota Re mutant (acetone-killed bacteria and Re-LPS) and Escherichia coli O14 (acetone-killed bacteria and enterobacterial common antigen, ECA) were studied in a mouse active protection test . Immunized mice were challenged with wild-type P . aeruginosa strains . It was established that P . aeruginosa LPS-defective mutants induced cross-immunity against different Fisher immunotypes of P . aeruginosa . S . minnesota Re-LPS and ECA gave mice protection against P . aeruginosa.

Infect Control Hosp Epidemiol, 1995 Apr, 16(4), 224 - 30
Characterization of nosocomial strains of Enterobacter aerogenes by arbitrarily primed-PCR analysis and ribotyping; Grattard F et al.; OBJECTIVE: To study the spread of strains of Enterobacter aerogenes in our hospital in 1992 and 1993 by using two genotypic markers, and to evaluate these methods for the epidemiological investigation of this species . DESIGN: Ribotyping (using two endonucleases) and arbitrarily primed (AP)-PCR (using two different 10-mer primers) were applied to the epidemiological typing of clinical strains of E aerogenes isolated from hospitalized patients . SETTING AND PATIENTS: The intensive care unit (ICU; 5 patients, 13 isolates), nephrology units (3 patients, 5 isolates), and surgery units (2 patients, 2 isolates) of the university hospital of Saint-Etienne (France) . RESULTS: Eight epidemiologically unrelated isolates, chosen as controls, exhibited distinct profiles, both by AP-PCR and ribotyping . Two clones of E aerogenes circulated in the ICU; both were isolated successively from samples of a single patient who stayed in the unit for almost 1 year . A third clone was recovered from patients of surgery units . A fourth clone was shown to have infected patients of nephrology units . CONCLUSIONS: Ribotyping and AP-PCR appear to be reliable methods for typing E aerogenes strains implicated in nosocomial infection . The spread of independent clones of E aerogenes in different units of our hospital in 1992 and 1993 was demonstrated by both methods . This study emphasizes the need to choose the endonucleases or primers with care to obtain high discriminatory results in genotypic investigations.

Tierarztl Prax, 1995 Apr, 23(2), 148 - 54
{Susceptibility of bacterial isolates from the equine respiratory tract to trimethoprim, sulfadoxine, sulfadimethoxine and combinations of these compounds}; Fey K et al.; Using a broth microdilution technique, the in vitro susceptibility of bacterial isolates from the equine respiratory tract to trimethoprim, sulfadoxine, sulfadimethoxine, and combinations of these compounds was determined . The bacterial strains (n = 88) isolated recently from horses with respiratory symptoms belonged to the following species: Streptococcus equi subsp . zooepidemicus (n = 34), Streptococcus equi subsp . equi (n = 22), Staphylococcus aureus (n = 9), Klebsiella pneumoniae (n = 7), Rhodococcus equi (n = 4), Pseudomonas spp . (n = 3) and Escherichia coli (n = 3) . In addition, two isolates of Enterobacter spp . and one isolate of Streptococcus equisimilis, Staphylococcus intermedius, Proteus mirabilis and Serratia marcescens were examined . For determination of susceptibility of an organism the following minimal inhibitory concentrations (MIC) were fixed as limiting values: Trimethoprim < or = 0.5 microgram/ml, sulfadoxine < or = 32 micrograms/ml, sulfadimethoxine < or = 32 micrograms/ml, trimethoprim/sulfadoxine < or = 0.5/32 micrograms/ml, trimethoprim/sulfadimethoxine < or = 0.5/32 micrograms/ml . As expected, Rhodococcus-equi-isolates were resistant to the antimicrobials tested . However, most of the clinically more common isolates showed a high degree of susceptibility to the combinations . The fractional inhibitory concentration (FIC) indices indicated synergism of the combination-partners in a wide range . According to these in vitro results, application of trimethoprim/sulfonamide combinations for the initial therapy of equine respiratory tract infections can be recommended.

Protein Expr Purif, 1995 Apr, 6(2), 176 - 84
Overexpression in Escherichia coli of the fdxA gene encoding Rhodobacter capsulatus ferredoxin II; Armengaud J et al.; Different gene expression systems were tested with the aim of overproducing the 7Fe ferredoxin (FdII) from Rhodobacter capsulatus in Escherichia coli . Plasmids bearing the Ptac, ParaB, fdxA gene, encoding FdII, under the control of the PlacUV5, P phi 10 promoters, were compared for their efficiency to promote the synthesis of recombinant ferredoxin . Using a P phi 10-based expression system, recombinant ferredoxin was obtained in a soluble apoform and accumulated up to 20% of the total cell protein . The ferredoxin polypeptide purified from such cells exhibited the correct molecular mass and no detectable heterogeneity when analyzed by mass spectrometry . When other expression systems were used, the ferredoxin was synthesized in holoform but in relatively smaller amounts (0.2 mg/liter of culture) . Factors such as promoter strength, efficient translation signals, and stability of the recombinant mRNA were shown to have little effect on the amount of 7Fe ferredoxin produced in E . coli . It is inferred that iron-sulfur clusters insertion may be a rate-limiting factor for synthesis of the 7Fe ferredoxin in the enterobacterium.

Tohoku J Exp Med, 1995 Apr, 175(4), 235 - 47
Antibiotic susceptibility of the sputum pathogens and throat swab pathogens isolated from the patients undergoing treatment in twenty-one private clinics in Japan; Watanabe A et al.; Bacteriology of the respiratory isolates from 2,539 patients with respiratory infections in 21 primary care clinics was documented . Of a total of 1,887 strains of potential pathogens recovered from 1,507 patients, 996 were gram-positive and 891 were gram-negative . Major pathogens were Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes . The MIC's against microbial isolates of six antimicrobial agents were determined . Ciprofloxacin and ofloxacin were more active against S . aureus, Moraxella catarrhalis and Pseudomonas aeruginosa, and ampicillin and cefteram were more active against S . pnuemoniae and S . pyogenes than four other antimicrobials tested, respectively, in this experiment . New quinolones and new generation cephems were active against H . influenzae and Enterobacteriaceae . Only one strain of S . aureus was methicillin-resistant . As regards other pathogens, 6.5% of S . pneumoniae and 14.9% of H . influenzae were resistant to ampicillin, and 26.7% of H . influenzae were beta-lactamase-positive . MRSA was found infrequently . But ampicillin-resistant S . pneumoniae and H . influenzae were found in primary care clinics almost as frequently as in intensive-medication-oriented clinics.

Pathol Biol (Paris), 1995 Apr, 43(4), 320 - 3
{Phenotypes of resistance to antibiotics of the most frequently isolated strains in five specialized hospital centers . Multicenter study}; Gabastou JM et al.; Antibiotic susceptibility of 948 bacterial strains isolated from varied samples essentially proceeding from urinary infections in five Paris psychiatric Hospitals was determined by disk diffusion method . E . coli, P . mirabilis, Klebsiella spp., P . aeruginosa et S . aureus are the predominant bacteria . 40% of S . aureus are methicilline resistant . Enterobacteriaceae are progressively becoming resistant to aminopenicillines, but remain sensitive to third generation cephalosporines . They are still susceptible to first generation quinolones . At least, if no resistance of P . aeruginosa to imipeneme has been reported, 30% of strains are resistant to ciprofloxacine . Resistance phenotypes to antibiotics of the strains isolated in patients from psychiatric Hospitals are located between those observed in out patients and in patients from general Hospitals . However, we noticed a worrying evolution of resistance to those encontered in psychiatric Hospitals . Therefore, a multiresistant strains emergence monitoring must be carried out regulary.

Pathol Biol (Paris), 1995 Apr, 43(4), 294 - 9
{Must pefloxacin and norfloxacin be studied separately against bacteria isolated from urinary tract infections by the API-ATB method?}; Soussy CJ et al.; 2113 bacterial strains were isolated from urinary tract infections in 1992 in 133 French pathology laboratories, 2069 strains were tested using the API-ATB method and the UR-14030 system including NFX and an additional test for PFX . Frequencies of susceptible (S), intermediate (I) and resistant (R) strains to PFX and NFX were respectively (%): 83.3; 8.6; 8.1 and 83.1; 9.5; 7; 4 . Overall rate of concordance (C), SS, II and RR, between the two antibiotics reached 92.8, minor discrepancies (Dm), SI, IS, RI and IR, 6.3 and major discrepancies (DM), SR and RS, 0.9 (K = 0.82) . For Enterobacteriaceae (n = 1830), frequencies of strains S, I and R were: 90.4; 5.9 and 3.7 with PFX and 90.4; 6.1 and 3.5 with NFX . Percentages of C, Dm and DM were 95.1; 4.4 and 0.5 respectively . The Lee test showed that results obtained with NFX and PFX were equivalent (p < 0.001) allowing to consider that the test of NFX is sufficient to conclude for susceptibility or resistance to both antibiotics using the API-ATB method and the UR-14030 system . Dm were probably related in some cases to a low level resistance mechanism and to the difference between the higher breakpoints (4 micrograms/ml for PFX and 8 micrograms/ml for NFX) . DM might be due to artefacts related to the bacterial inoculum size or to the antibiotic concentration obtained in the cupules.

Pathol Biol (Paris), 1995 Apr, 43(4), 253 - 7
{In vitro activity of six beta-lactams against 295 strains of enterobacteriaceae and P . aeruginosa isolated from neutropenic patients}; Maugein J et al.; The in vitro activity of two new beta-lactam agents, cefpirome (CPO) and cefepime (FEP), was investigated against 295 Gram-negative bacilli (250 enterobacteriaceae and 45 P . aeruginosa) isolated from neutropenic patients . They were compared with ceftazidime (CAZ), piperacillin-tazobactam (TZP), imipenem (IPM) and cefotaxime (CTX) . All enterobacteriacae were susceptible to IPM, 16 strains were intermediately susceptible or resistant to CAZ (1 strain of E . coli, 4 of Morganella morganii and 11 of Enterobacter . The 250 strains of enterobacteriacea were susceptible to FEP (MIC < 1 mg/l) and only one strain among them was intermediately susceptible to CPO . Among 45 strains of P . aeruginosa, 21 strains were susceptible to CPO, 30 to FEP, 31 to TZP, 32 to CAZ and 34 to IPM . All the strains were inhibited by less than 32 mg/l of FEP and IPM.

Biochemistry, 1995 Mar 21, 34(11), 3569 - 75
Inactivation of the Enterobacter cloacae P99 beta-lactamase by a fluorescent phosphonate: direct detection of ligand binding at the second site; Dryjanski M et al.; The synthesis of a fluorescent beta-lactamase inhibitor, p-nitrophenyl {(dansylamido)methyl}-phosphonate is described . The compound inactivated the class C beta-lactamase of Enterobacter cloacae P99 with stoichiometric release of p-nitrophenol, presumably, as with other phosphonate inhibitors, by phosphonylation of the active site serine . The inhibited enzyme exhibited typical dansyl fluorescence emission at 533 nm with excitation maxima at 345 and 283 nm; the latter excitation peak probably arises from radiationless energy transfer to the dansyl group from aromatic chromophores on the protein-inspection of the crystal structure shows that the closest are tyrosines . The fluorescence of the p-nitrophenyl phosphonate and the inhibited enzyme varied with pH in a very similar fashion, reflecting dissociation of the dimethylammonium ion in the ground state at low pH and of the sulfonamide in the excited state above pH 6 . No perturbation of the fluorescence of the inhibited enzyme due to active site functional groups was observed . This may reflect the distance between the dansyl fluorophore and the phosphonyl group and/or the high pKa's of the protonated active site functional groups in the presence of the phosphonate . The addition of certain small molecular weight N-acyl amino acids, of preferred structure D-RCONHCHR'CO2-, to the inhibited enzyme led to an enhancement of dansyl fluorescence intensity and a blue shift in the emission maximum . This suggested that these molecules bind to the beta-lactamase at a site other than the active site and supports previous kinetic data to this effect {Dryjanski, M., & Pratt, R . F., (1995) Biochemistry 34, preceding paper in this issue}.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemistry, 1995 Mar 21, 34(11), 3561 - 8
Steady-state kinetics of the binding of beta-lactams and penicilloates to the second binding site of the Enterobacter cloacae P99 beta-lactamase; Dryjanski M et al.; Previous research has shown that the class C beta-lactamase of Enterobacter cloacae P99 is able to catalyze the hydrolysis and aminolysis of acyclic depsipeptides . The steady kinetics of these reactions are complicated by the presence of an additional (depsi)peptide binding site in addition to the active site {Pazhanisamy, S., & Pratt, R . F . (1989) Biochemistry 28, 6875-6882} . The present paper presents a steady-state kinetic analysis of the inhibition of depsipeptide hydrolysis by sodium benzylpenicilloate, methyl benzylpenicilloate, 6-aminopenicillanic acid, and 7-aminocephalosporanic acid . The two beta-lactams are considerably poorer substrates than the depsipeptide employed, m-{{(phenylacetyl)glycyl}oxy}benzoic acid . The aim was to determine the relative affinity of these ligands for the active site and the second site . Three types of experiments were employed: (i) measurements of direct inhibition of depsipeptide hydrolysis, (ii) measurements of the effect of an active-site-directed inhibitor, m-(dansylamidophenyl)-boronic acid, on the effectiveness of the ligands as inhibitors, and (iii) measurements of the effect of a preferential second site ligand, N-(phenylacetyl)glycyl-D-phenylalanine, on the effectiveness of the ligands as inhibitors . The results suggest that all four ligands preferentially bind to the active site, with weaker binding at the second site . The necessarily weaker binding of a ligand to the second site when the active site is occupied by a transition-state analog inhibitor was analyzed . Perhaps surprisingly, the intact beta-lactams appeared to bind more firmly to the alternative site than do the flexible penicilloates.(ABSTRACT TRUNCATED AT 250 WORDS)

J Biol Chem, 1995 Mar 17, 270(11), 5729 - 35
Molecular evolution of a class C beta-lactamase extending its substrate specificity; Nukaga M et al.; Enterobacter cloacae GC1, a clinical strain isolated in 1992 in Japan, was found to produce a chromosomal class C beta-lactamase with extended substrate specificity to oxyimino beta-lactam antibiotics, significantly differing from the known E . cloacae beta-lactamases such as the P99 beta-lactamase . The 1560 nucleotides including the GC1 beta-lactamase gene were sequenced, and the amino acid sequence of the mature enzyme comprising 364 amino acids was deduced . A comparison of the amino acid sequence with those of known E . cloacae beta-lactamases revealed the duplication of three amino acids at positions 208-213, i.e . Ala-Val-Arg-Ala-Val-Arg . This duplication was attributed to a tandem duplication of a 9-nucleotide sequence . The chimeric beta-lactamases produced by the chimeric genes from the GC1 and P99 beta-lactamase genes indicated that the extended substrate specificity is entirely attributed to the 3-amino acid insertion . Two mutant beta-lactamases were prepared from P99 beta-lactamase by site-directed mutagenesis, i.e . an Ala-Ala-Ala sequence was inserted before or after the native Ala-Val-Arg at positions 208-210 . These mutant enzymes revealed that the Ala-Val-Arg located from positions 211 to 213 in the GC1 beta-lactamase are the newly inserted residues, and this phenomenon is independent of the characteristics of the amino acids inserted.

J Med Chem, 1995 Mar 17, 38(6), 1022 - 34
Synthesis and biological activity of 7-alkylidenecephems; Buynak JD et al.; Several 7-alkylidenecephalosporins were synthesized and biologically evaluated as beta-lactamase inhibitors . The three beta-lactamase enzymes used in this study included two type C beta-lactamases, derived from Enterobacter cloacae P99 and E . cloacae SC12368, and one type A beta-lactamase, derived from Escherichia coli WC3310 . Of the cephalosporins prepared, compound 7e, the sodium salt of 7-{(Z)-(2'-pyridyl)methylene}cephalosporanic acid sulfone, was found to have excellent inhibitory properties against both type C enzymes . Also, compound 7f, the sodium salt of 7-{(Z)-(tert-butoxycarbonyl)methylene}cephalosporanic acid sulfone showed high activity as an inhibitor of the type A enzyme . The inhibition kinetics of 7e were further explored . The IC50 value of 7e indicated that this compound was approximately 20-fold more active than tazobactam against the enzyme derived from E . cloacae P99 and 167-fold more active than tazobactam against the enzyme derived from E . cloacae SC12368 . A plot of enzymatic activity vs incubation time with stoichiometric amounts of inhibitor reveals a rapid deactivation of the enzyme followed by an extremely slow reactivation . 7e exhibited a second-order rate constant of k3' = 5.3 x 10(6) L/mol.min, and a partition ratio of approximately 20:1 inhibitor:enzyme was determined for this inhibitor . After separation of excess inhibitor with Sephadex filtration, a rate constant of enzyme reactivation was measured at kreactiv = 1.0 x 10(-3) s-1 . Following 24 h of incubation of enzyme with a large excess of inhibitor and sephadex filtration to remove excess inhibitor, the enzyme was able to recover only 43% of its original activity, indicating an irreversible component to the inhibition . Potential mechanisms of inhibition for both 7e and 7f are suggested.

FEMS Microbiol Lett, 1995 Mar 15, 127(1-2), 145 - 9
Iron uptake in Pseudomonas aeruginosa mediated by N-(2,3-dihydroxybenzoyl)-L-serine and 2,3-dihydroxybenzoic acid; Screen J et al.; Pseudomonas aeruginosa is known to have an inducible uptake system for the enterobacterial siderophore enterobactin . In this work we have examined iron transport mediated by the biosynthetic precursor 2,3-dihydroxybenzoic acid and N-(2,3-dihydroxybenzoyl)-L-serine, a breakdown product of enterobactin . Iron complexed with 2,3-dihydroxybenzoyl-L-serine was transported into P . aeruginosa IA1 via a transport system which is energy-dependent and iron-repressible . The rate of transport was not altered by growing the cells in the presence of either pyoverdin or pyochelin, which have been shown previously to induce transport via that system . Growth of the cells in the presence of enterobactin did cause an increase in the rate of transport, indicating that the complex can be transported by the inducible enterobactin uptake system, but also that a separate system must exist . In contrast, transport of iron complexed with 2,3-dihydroxybenzoic acid was neither iron-repressible nor strongly energy-dependent, from which we conclude that there must be a novel mode of transport not characteristic of iron-siderophore transport systems.

Biochem Pharmacol, 1995 Mar 15, 49(6), 763 - 6
Deglycosylation of antiherpesviral 5-substituted arabinosyluracil derivatives by rat liver extract and enterobacteria cells; Machida H et al.; A number of antiherpesviral 5-substituted derivatives of 1-beta-D-arabinofuranosyluracil (araU) were significantly resistant to phosphorolysis by rat liver extract (S-9), but were gradually deglycosylated in a 2% enterobacteria cell suspension . The relative order of the resistance conferred by the different C-5 substituents was: 5-propynyl > 5-(E)-2-bromovinyl > 5-(E)-2-chlorovinyl > 5-methyl > 5-iodo . The 2'-fluoro derivatives of araU were completely resistant to phosphorolysis by both liver extract and enterobacteria, whereas the corresponding ribofuranosyl and 2'-deoxyribofuranosyl nucleosides were easily phosphorolysed by S-9, and were immediately cleaved in a 1% enterobacteria cell suspension . These findings suggest that antiherpesviral 5-substituted araU analogues can be relatively stable in vivo, when injected intravenously, and that degradation of 1-beta-D-arabinofuranosyl-5-(E-2-bromovinyl)uracil (sorivudine) following oral administration is due primarily to the action of enterobacteria.

Proc Natl Acad Sci U S A, 1995 Mar 14, 92(6), 2081 - 5
FimH adhesin of type 1 pili is assembled into a fibrillar tip structure in the Enterobacteriaceae; Jones CH et al.; Type 1 pili are heteropolymeric mannosebinding fibers produced by all members of the Enterobacteriaceae family . The bulk of the fiber is composed of FimA . Two macromolecular complexes responsible for mediating an interaction with mannose-containing receptors were purified from fimA- Escherichia coli by mannose affinity chromatography and ion-exchange chromatography . One complex contained only the mannose-binding adhesin, FimH, associated with FimG, a minor component of the type 1 pilus . In the other complex the FimG-FimH moiety was loosely associated with a chaperone-minor subunit complex (FimC-FimF), possibly representing an intermediate in tip fibrilla assembly . The FimC chaperone has also been shown to form a preassembly complex with FimH that has been purified and characterized previously . Purified FimC did not bind to the FimG-FimH complex but did recognize FimH dissociated from the FimG-FimH complex . Quick-freeze deep-etch electron microscopy revealed that the FimG-FimH complex had a thin fibrillar architecture . High-resolution electron microscopy of type 1 pili revealed that a 16-nm fibrillar tip structure with an architecture identical to that of the FimG-FimH complex was joined end-to-end to the pilus rod . In a fimH- deletion mutant, the tip fibrillae joined to pilus rods were approximately 3 nm in length . The full-length tip fibrilla was restored by complementation with the fimH gene in trans . The bipartite nature of the type 1 pilus was also demonstrated on pili purified from clinical isolates of members of the Enterobacteriaceae family arguing that it is a conserved feature of the type 1 pilus.

Acta Pol Pharm, 1995 Mar-Apr, 52(2), 161 - 71
Susceptibility of gram-negative bacteria isolated from a paediatric hospital environment to antibiotics; Zembrzuska-Sadkowska E et al.; The majority of tested Gram-negative strains isolated from the hospital environment were resistant to 6-14 used antibiotics . The greatest resistance was shown by three strains: Enterobacter cloacae, Proteus mirabilis and Ps . maltophilia, which were resistant to all tested drugs . The most effective antibiotic was gentamicin, at least against half of bacteria belonging to Enterobacteriaceae family, to 90% of strains from Pseudomonas genus and to all other Gram-negative rods . Cephtazidim, cephotaxim, colistin and carbenicillin were effective only to 60-70% of Enterobacteriaceae family strains, whereas ampicillin and tetracycline to 70% of Pseudomonas genus . Other Gram-negative bacilli were more susceptible to antibiotics . Cephalothin was ineffective to all tested strains.

Pediatr Pathol Lab Med, 1995 Mar-Apr, 15(2), 269 - 81
Infections in children with human immunodeficiency virus/acquired immunodeficiency syndrome: an autopsy study of 30 cases in south Florida, 1990-1993; Reik RA et al.; Thirty autopsies performed on infants and children with HIV infection and/or AIDS were reviewed for the presence and type of infection . Twenty-six (87%) demonstrated evidence of infection in addition to HIV at the time of postmortem examination . Pathogenic bacterial infectious were the most frequently encountered, seen in 15 of the cases . Nine of the 15 (60%) were due to gram-negative rods, most commonly Pseudomonas aeruginosa . Infections with gram-negative organisms often involved multiple organ systems and were frequently undiagnosed both pre- and postmortem because of variability in culture results and difficulties in identification both clinically and in tissue sections . Discussion is presented of unusual staining characteristics and filamentous morphology found with these pathogens . Other pathogenic bacteria encountered were Klebsiella pneumoniae, Escherichia coli, Enterobacter sp., and Staphylococcus . Fungal infections due to Candida species were present in nine cases (31%) but were invasive in only two of these . One instance of Aspergillus meningo-encephalitis was noted . Proven viral infections were present in five children (three cytomegalovirus, one herpes simplex, and one adenovirus) . Pneumocystis carinii pneumonia was diagnosed in five of the patients (17%), and one instance of disseminated Mycobacterium avium-intracellulare was encountered.

Acta Obstet Gynecol Scand, 1995 Mar, 74(3), 216 - 9
Sterility of the uterine cavity; Moller BR et al.; In a prospective open study the sterility of the uterine cavity was evaluated in 99 women admitted for hysterectomy . The indications for hysterectomy were in most cases persistent irregular vaginal bleeding and fibromyomas of the uterus . Samples for both aerobic and anaerobic bacteria, Chlamydia trachomatis, yeasts and viruses were taken preoperatively from the apex of the vagina and cervical os . Immediately after hysterectomy the uterus was opened under sterile conditions and samples obtained from the isthmus and fundus of the uterine cavity for microbiological examination . Wet smears were taken from the same sites . Nearly a quarter of all the patients harbored one or more microorganisms in the uterus, mostly Gardnerella vaginalis, Enterobacter and Streptococcus agalactiae . We found that in a significant number of cases, the uterine cavity is colonized with potentially pathogenic organisms which may play a causative role in endometritis . The results indicate that inflammation of the uterine cavity should be evaluated by hysteroscopic examination before hysterectomy is undertaken in patients with persistent irregular vaginal bleeding.

J Bacteriol, 1995 Mar, 177(6), 1624 - 6
The amino acid sequence of Lrp is highly conserved in four enteric microorganisms; Friedberg D et al.; Lrp (leucine-responsive regulatory protein) is a global regulator of metabolism in Escherichia coli (J . M . Calvo and R . G . Matthews, Microbiol . Rev . 58:466-490, 1994) . The lrp genes from three other enteric microorganisms, Enterobacter aerogenes, Klebsiella aerogenes, and Salmonella typhimurium, were cloned and sequenced . An analysis of these sequences and of the previously determined sequence from E . coli indicated that the vast majority of changes were synonymous rather than nonsynonymous changes . Nucleotide changes occurred at 89 of 492 positions but resulted in amino acid changes at only 2 of 164 positions . This analysis suggests that the Lrp amino acid sequence is highly adapted for function and that almost all amino acid changes lead to a protein that functions less well than the wild-type protein.

J Bacteriol, 1995 Mar, 177(6), 1595 - 609
Genetic and molecular characterization of the polar flagellum of Vibrio parahaemolyticus; McCarter LL; Vibrio parahaemolyticus possesses two alternate flagellar systems adapted for movement under different circumstances . A single polar flagellum propels the bacterium in liquid (swimming), while multiple lateral flagella move the bacterium over surfaces (swarming) . Energy to rotate the polar flagellum is derived from the sodium membrane potential, whereas lateral flagella are powered by the proton motive force . Lateral flagella are arranged peritrichously, and the unsheathed filaments are polymerized from a single flagellin . The polar flagellum is synthesized constitutively, but lateral flagella are produced only under conditions in which the polar flagellum is not functional, e.g., on surfaces . This work initiates characterization of the sheathed, polar flagellum . Four genes encoding flagellins were cloned and found to map in two loci . These genes, as well as three genes encoding proteins resembling HAPs (hook-associated proteins), were sequenced . A potential consensus polar flagellar promoter was identified by using upstream sequences from seven polar genes . It resembled the enterobacterial sigma 28 consensus promoter . Three of the four flagellin genes were expressed in Escherichia coli, and expression was dependent on the product of the fliA gene encoding sigma 28 . The fourth flagellin gene may be different regulated . It was not expressed in E . coli, and inspection of upstream sequence revealed a potential sigma 54 consensus promoter . Mutants with single and multiple defects in flagellin genes were constructed in order to determine assembly rules for filament polymerization . HAP mutants displayed new phenotypes, which were different from those of Salmonella typhimurium and most probably were the result of the filament being sheathed.

Gastroenterology, 1995 Mar, 108(3), 860 - 4
Molecular genetic evidence of bacterial colonization of cholesterol gallstones; Swidsinski A et al.; BACKGROUND/AIMS: Cholesterol gallstone formation is believed to be unrelated to the presence of bacteria because attempts to culture potentially causative bacteria from surgically removed cholesterol stones have failed . However, the formation of gallbladder gallstones takes years . Embedded bacteria may be damaged or killed . The aim of this study was to search for bacterial DNA sequences in cholesterol stones with negative bacterial culture . METHODS: Bacterial gene fragments were amplified in vitro from DNA extracted from cholesterol gallbladder stones . Comparative 16S ribosomal RNA sequence analysis was used for identification . RESULTS: Gallstones with cholesterol content between 70% to 90% harbored bacterial DNA (16 of 17 patients) . No bacterial DNA was found in the gallstones with cholesterol content of > 90% (3 patients) . Three bacterial groups typical for gallstone colonization were identified . Propionibacteria-related DNA was found in the stones of 9 patients (45%) . Enterobacterial type sequences were obtained in 5 patients (25%) . A more heterogenous sequence collection was retrieved from 7 patients (35%) and could be assigned to the major bacterial line of gram-positive bacteria with a low DNA guanine and cytosine content . CONCLUSIONS: Most cholesterol gallstones harbor bacterial DNA . It is important to determine the actual role of these microorganisms in gallstone formation.

Am J Clin Pathol, 1995 Mar, 103(3), 320 - 3
Evaluation of the automated Bact-Alert system for pediatric blood culturing; Pickett DA et al.; The Organon Teknika BacT/Alert (Organon Teknika, Durham, NC), using the Pedi-BacT 20 mL aerobic bottle (BPBCS) was compared to the Wampole Isolator (WI) 1.5 Microbial tube (Wampole Laboratories, Cranbury, NJ), for detection and recovery of pediatric pathogens . The BPBCS continuously monitors culture bottles for changes in CO2 concentrations, while WI cultures are examined twice daily for appearance of colonial growth on agar media . Of 5,175 paired blood cultures, 383 pathogens were recovered from 606 positive cultures . There were 272 pathogens recovered by both systems, 64 from BPBCS only, and 47 from WI only . Overall recovery rates were 88% for BPBCS and 83% for WI . There was no significant difference between the two systems in detection or times to positivity of staphylococci, Enterobacteriaceae, or pseudomonads . Trends toward better recovery of streptococci (20 vs . 10) and fastidious microaerophiles (3 vs . 0) were found with BPBCS, whereas more slowly growing pathogens (Rochalimaea henselae {1}, Mycobacterium avium-intracellulare {1}) were recovered by WI only, but because of their lower frequency did not achieve statistical significance . Detection of Haemophilus influenzae (14.9 hours in WI vs . 45.4 hours in BPBCS) was faster with WI . False positive plus contaminant cultures were detected in 5.9% BPBCS versus 1.5% WI . BPBCS offers detection of bacteremia at a rate comparable to WI with advantages of automation.

Infect Immun, 1995 Mar, 63(3), 989 - 93
Pasteurella multocida produces a protein with homology to the P6 outer membrane protein of Haemophilus influenzae; Kasten RW et al.; An antibody specific for a 16-kDa outer membrane protein of a rabbit strain of Pasteurella multocida was used to probe representatives of all 16 somatic serotypes of P . multocida, as well as the vaccine strains CU and M9, and all were shown to express the protein . The gene encoding this protein was cloned and sequenced and found to have extensive sequence homology with the gene encoding the P6 protein of Haemophilus influenzae . The protein in P . multocida has been designated P6-like . The gene encoding the P6-like protein was used to probe members of the family Pasteurellaceae and other gram-negative bacteria . Representatives of all 16 somatic serotypes (as well as the vaccine strains CU and M9) of P . multocida hybridized with the P6-like gene under conditions of high stringency . The DNA from H . influenzae hybridized weakly with the P6-like gene under these conditions, but Pasteurella haemolytica (representatives of A and T biotypes), Bordetella bronchiseptica, B . avium, Actinobacillus suis, A . suis-like, A . lignieresii, A . ureae, A . rossii, A . pleuropneumoniae, A . equuli, and various members of the family Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium) did not hybridize detectably . Under conditions of lower stringency, the P6-like gene also hybridized strongly with DNA from P . multocida, H . influenzae, and A . rossii but weakly with DNA from P . haemolytica and members of the genus Actinobacillus . These results suggest that the P6-like protein of P . multocida might be useful as an immunizing product to protect poultry from avian cholera . This suggestion stems from (i) our finding that the P6-like protein in P . multocida is widely distributed among all the somatic serotypes and (ii) the previous work of others demonstrating that the P6 protein of H . influenzae elicits a protective immune response in animal models of human disease.

Infect Immun, 1995 Mar, 63(3), 903 - 10
A porin from Klebsiella pneumoniae: sequence homology, three-dimensional model, and complement binding; Alberti S et al.; A recombinant plasmid containing ompK36, the gene coding for the Klebsiella pneumoniae outer membrane protein OmpK36, was constructed by transposon mutagenesis and subcloning . Clones were identified in a cosmid library in Escherichia coli on the basis of their reaction with antiserum against the OmpK36 protein and by the presence in gel electrophoretic analysis of a band in E . coli outer membranes migrating with a mobility corresponding to 36 kDa . The ompK36-encoded protein exhibited characteristic properties of porins, such as heat modifiability and resistance to trypsin . The sequence of the gene revealed that OmpK36 is a close relative of the enterobacterial porin family, with a high degree of homology with E . coli OmpC, PhoE, and OmpF . On the basis of the structures of OmpF and PhoE porins, determined previously by X-ray analysis, it appears likely that the three-dimensional structure of OmpK36 also contains the motif of a 16-stranded beta-barrel, with long loops on one end and short turns on the other . Like the OmpC porin from E . coli, OmpK36 contains a long insertion in loop 4 . The results of a binding study of complement component C1q to OmpK36 and the analysis of the OmpK36 model suggest that C1q binding sites are covered by the lipopolysaccharide core in the native porin.

Infect Immun, 1995 Mar, 63(3), 818 - 24
Molecular cloning and characterization of the nontypeable Haemophilus influenzae 2019 rfaE gene required for lipopolysaccharide biosynthesis; Lee NG et al.; The lipooligosaccharide (LOS) of nontypeable Haemophilus influenzae (NTHi) is an important factor in pathogenesis and virulence . In an attempt to elucidate the genes involved in LOS biosynthesis, we have cloned the rfaE gene from NTHi 2019 by complementing a Salmonella typhimurium rfaE mutant strain with an NTHi 2019 plasmid library . The rfaE mutant synthesizes lipopolysaccharide (LPS) lacking heptose, and the rfaE gene is postulated to be involved in ADP-heptose synthesis . Retransformation with the plasmid containing 4 kb of NTHi DNA isolated from a reconstituted mutant into rfaE mutants gave wild-type LPS phenotypes . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis confirmed the conversion of the rfaE mutant LPS to a wild-type LPS phenotype . Sequence analysis of a 2.4-kb BglII fragment revealed two open reading frames . One open reading frame encodes the RfaE protein with a molecular weight of 37.6 kDa, which was confirmed by in vitro transcription and translation, and the other encodes a polypeptide highly homologous to the Escherichia coli HtrB protein . These two genes are transcribed from the same promoter region into opposite directions . Primer extension analysis of the rfaE gene revealed a single transcription start site at 37 bp upstream of the predicted translation start site . The upstream promoter region contained a sequence (TA AAAT) homologous to the -10 region of the bacterial sigma 70-dependent promoters at an appropriate distance (7 bp), but not sequence resembling the consensus sequence of the -35 region was found . These studies demonstrate the ability to use complementation of defined LPS defects in members of the family Enterobacteriaceae to identify LOS synthesis genes in NTHi.

Lett Appl Microbiol, 1995 Mar, 20(3), 160 - 3
Oligonucleotide probes specific for the genus Salmonella and for Salm . typhimurium; Olsen JE et al.; Synthetic oligonucleotides have been deduced and synthesized based on the sequence of a salmonella-specific polynucleotide probe . Two oligonucleotide probes, ST4 and ST15rev hybridized to 93 and 92 strains respectively out of 93 strains of Salmonella analysed . ST4, however, cross hybridized to one of the 28 strains of 16 genera of Enterobacteriaceae tested . Based on sequence alignment, in 16 strains of Salmonella, of a 114 base pair region, a Salm . typhimurium specific oligonucleotide probe, ST22, was identified . In colony hybridization, this probe detected all 47 strains of Salm . typhimurium analysed without hybridization to 94 strains of other Salmonella serotypes and to 26 strains of non-Salmonella bacteria.

Clin Infect Dis, 1995 Mar, 20(3), 712 - 4
Bacteremia due to vancomycin-dependent Enterococcus faecium; Green M et al.; A recipient of small-bowel and liver transplants developed recurrent fever and polymicrobial bacteremia due to multiply resistant Enterobacter cloacae and an inducible VanB strain of Enterococcus faecium while receiving therapy with amikacin, imipenem, and vancomycin . These organisms could not be subcultured onto blood agar but did grow around the vancomyin disk on a direct-susceptibility test plate . Additional testing confirmed the strain as E . faecium, which would not grow in the absence of vancomycin . Growth around a disk containing D-alanyl-D-alanine was demonstrated . Spontaneous vancomycin-independent revertants were obtained at a frequency of approximately 1 x 10(-6) . Two classes of vancomycin-independent revertants were obtained: one that was constitutively vancomycin resistant and one that was nonconstitutively vancomycin resistant . We hypothesize that the normal D-ala ligase is not expressed in the vancomycin-dependent strain; thus survival of these strains is dependent on expression of the VanB ligase, which produces a depsipeptide precursor that is resistant to vancomycin binding . This is the second reported case involving a clinically important vancomycin-dependent enterococcal strain . Awareness of the existence of these strains is important, especially when clinical and microbiological data are consistent with infection due to a fastidious or nutritionally-deficient organism.

Jpn J Antibiot, 1995 Mar, 48(3), 421 - 6
{Beta-lactamase production of clinically isolated bacteria}; Deguchi K et al.; We examined beta-lactamase productions by clinically isolated strains of bacteria . The results were as follows; 1 . It appears that beta-lactamases produced by strains of five species of Staphylococcus spp . are mostly penicillinase (90%) . Source of beta-lactamase producing strains of Haemophilus influenzae (23%) and all of Moraxella subgenus Branhamella catarrhalis: strains (100%) are "High & Low producer" strains . 2 . A large proportion of beta-lactamase producing strains of Enterobacteriaceae and Bacteroides fragilis group appeared to be "High producer" 3 . beta-lactamase producing abilities are different among glucose non-fermentative Gram-negative rods . It appears that some of the strains appeared to be "High producers".

Can J Microbiol, 1995 Mar, 41(3), 217 - 26
Protection against bacteriocin 28b in Serratia marcescens is apparently not related to the expression of an immunity gene; Viejo MB et al.; The gene encoding bacteriocin 28b from Serratia marcescens N28b (bss gene) has been cloned in Escherichia coli and its nucleotide sequence has been determined . The genetic determinants coding for other well-characterized bacteriocins from enterobacteria (colicins) are located in plasmids and they have always been shown to contain a gene responsible for immunity located downstream from the bacteriocin structural gene . In some cases there is another gene located downstream from the immunity gene, which is responsible for bacteriocin release . Analysis of bacteriocin 28b release and the sensitivity to this bacteriocin of E . coli strains harbouring recombinant plasmids containing the bss gene showed that bacteriocin 28b is not released from the cell in these strains and that their phenotypic insensitivity is not associated with any region close to the structural gene . The nucleotide sequence of the region downstream from the bss gene contains two putative open reading frames transcribed in the opposite direction to the bss gene . These open reading frames apparently encode proteins that seem not to be involved in bacteriocin immunity or release . Moreover, a S . marcescens N28b genomic library was screened and no immunity gene was found . Therefore, bacteriocin 28b differs greatly from the bacteriocins from other enterobacteria, and in the following senses it is unique: firstly, the gene encoding bacteriocin 28b seems to be located on the chromosome, and secondly, insensitivity to this bacteriocin in S . marcescens N28b is not associated with the expression of an immunity gene.

J Appl Bacteriol, 1995 Mar, 78(3), 281 - 9
Selective action of inhibitors used in different culture media on the competitive microflora of Salmonella; Arroyo G et al.; The action of 12 inhibitors employed in the culture media used to detect the presence of Salmonella in food on 24 bacterial strains including contaminating Gram-positive bacteria common in water and food, Gram-negative bacteria, especially Enterobacteriaceae and Pseudomonadaceae, which are components of the competitive microflora, and six Salmonella serotypes was tested . Two liquid culture media (AR 5 and AE 1) were used . Series of tubes containing increasing concentrations of each inhibitor were inoculated with the test strains and incubated at 37 degrees C until growth was verified spectrophotometrically (24-48 h) . The results showed that the inhibitors were effective against the Gram-positive contaminating microflora . They did not preferentially inhibit the competitive microflora of Salmonella, chiefly Enterobacteriaceae, and were ineffective against the Pseudomonas strains, which can tolerate concentrations higher than those customarily employed in culture media.

FEMS Microbiol Lett, 1995 Mar 1, 126(3), 233 - 9
Cloning and nucleotide sequence of the signal peptidase II (lsp)-gene from Staphylococcus carnosus; Witke C et al.; Staphylococcus carnosus TM300 is able to synthesize at least seven lipoproteins with molecular masses between 15 and 45 kDa; the proteins are located in the membrane fraction . It can be concluded that this strain also posesses the enzymes involved in lipoprotein modification and prolipoprotein signal peptidase (signal peptidase II) processing . The gene encoding the prolipoprotein signal peptidase, lsp, from Staphylococcus carnosus TM300 was cloned in Escherichia coli and sequenced . The deduced amino acid sequence of the Lsp showed amino acid similarities with the Lsp's of S . aureus, Enterobacter aerogenes, E . coli, and Pseudomonas fluorescens . The hydropathy profile reveals four hydrophobic segments which are homologous to the putative transmembrane regions of the E . coli signal peptidase II . E . coli strains carrying lsp of S . carnosus exhibited an increased globomycin resistance.

Pathol Biol (Paris), 1995 Mar, 43(3), 208 - 14
{In vitro antibacterial activity of piperacillin-tazobactam in combination with netilmicin or amikacin against Enterobacteriaceae resistant to amoxicillin}; Duez JM et al.; The antibacterial in vitro activity of piperacillin and tazobactam (in a concentration ratio of 8/1) was studied in combination with netilmicin or amikacin by a microtiter checkerboard assay against 162 strains of Enterobacteriaceae . These strains were selected for their resistance pattern to beta-lactam antibiotics and their beta-lactamases were characterized by the mean of isoelectric focusing in comparison with reference strains . A comparison of the MICs of piperacillin, alone and in combination, assessed the efficacy of tazobactam as beta-lactamase inhibitor, particularly when a TEM-1 beta-lactamase was produced . When the strains were sensitive to the aminoglycosides (111 netilmicin-sensitive ones and 131 amikacin-sensitive ones), we observed 55% of synergistic effects and 45% of additions with the combinations piperacillin-tazobactam-netilmicin or amikacin . A synergistic effect was usually encountered with P . mirabilis, P . vulgaris, M . morganii and with the strains of E . coli, E . cloacae and S . marcescens which produced a cephalosporinase only . Among the 51 strains that were intermediate or resistant to netilmicin, 8 ones were inhibited by piperacillin-tazobactam-netilmicin at therapeutic levels (3 synergisms, 5 additions) . Among the 31 strains that were intermediate or resistant to amikacin, 24 ones (18 synergisms, 6 additions) were inhibited by piperacillin-tazobactam-amikacin at therapeutic concentrations . In most of the cases, the combination of piperacillin-tazobactam with an aminoglycoside enhanced the antibacterial activity of these agents by decreasing the concentrations necessary to inhibit the strains.

Zh Mikrobiol Epidemiol Immunobiol, 1995 Mar-Apr, (2), 101 - 4
{The efficacy of using an immune lactoglobulin preparation for correcting intestinal dysbacteriosis in newborn infants}; Kushnareva MV et al.; The comparative study of the effectiveness of immune immunoglobulin and bifidumbacterin for the correction of dysbiotic microflora in the intestine of premature born children with infectious inflammatory diseases . Immune lactoglobulin was administered orally to 37 children in a dose of 500 mg/kg twice a day for 1-3 weeks . The preparation facilitated the rapid and stable normalization of disturbances in the intestinal biocenosis in 86.5% of newborns . The elimination of opportunistic lactose-negative enterobacteria, Pseudomonas aeruginosa hemolytic forms of Escherichia from the digestive tract and the stimulation of the multiplication of lactic acid bacteria were noted . The treatment of newborns with immune lactoglobulin was found to give a more pronounced corrective effect with respect of intestinal microflora than the use of bifidumbacterin according to the traditional scheme.

Diagn Microbiol Infect Dis, 1995 Mar, 21(3), 153 - 68
Comparative antimicrobial activity of piperacillin-tazobactam tested against more than 5000 recent clinical isolates from five medical centers . A reevaluation after five years; Marshall SA et al.; Piperacillin combined with tazobactam at a fixed concentration (4 micrograms/ml) and a ratio (8:1) was tested against 5,029 aerobic isolates and 447 fastidious organisms, including anaerobes . Among the Enterobacteriaceae, > 95% inhibition was shared only by imipenem (99.1% at < or = 4 micrograms/ml), and some newer cephalosporins (95.1% - 99.8% at < or = 8 micrograms/ml), and piperacillin-tazobactam (95.8% at < or = 16/4 micrograms/ml) . Piperacillin-tazobactam was the most active agent tested against nonenteric Gram-negative bacilli (93.5% at < or = 8 micrograms/ml) . Ampicillin-sulbactam was the most active agent against staphylococci (95.0% at < or = 8 micrograms/ml), followed by imipenem (91.8%), piperacillin-tazobactam (89.3% at < or = 8/4 micrograms/ml), and cefepime (86.2% at < or = 8 micrograms/ml) . Against the enterococci, only ampicillin (93.0% at < or = 8 micrograms/ml) with or without sulbactam, piperacillin (91.0% at < or = 16 micrograms/ml) with or without tazobactam, and imipenem (91.0%) had acceptable activity . Piperacillin-tazobactam and imipenem were the most active drugs tested against all aerobic isolates, inhibiting 93.5% of isolates each . Piperacillin-tazobactam inhibited all fastidious isolates tested, including Haemophilus influenzae (MIC90, 0.094/4 micrograms/ml), Moraxella catarrhalis (MIC90, 0.064/4 micrograms/ml), Neisseira gonorrhoeae (MIC90, < or = 0.016/4 micrograms/ml), and Streptococcus pneumoniae (all MICs, < or = 4/4 micrograms/ml) . Against the anaerobic isolates, the most broad-spectrum antimicrobial agents tested were imipenem (100.0%), piperacillin-tazobactam (99.5% at < or = 32/4 micrograms/ml), metronidazole (98.4% at < or = 8 micrograms/ml), and ticarcillin-clavulanic acid (95.1% at < or = 32/2 micrograms/ml) . These results are nearly identical to a previous study involving the same five medical centers in 1989 . Piperacillin-tazobactam appears to remain a highly effective beta-lactamase inhibitor combination with a wide empiric spectrum and potency in teaching hospitals.

Klin Lab Diagn, 1995 Mar-Apr, (2), 40 - 2
{The colicin selection of the S forms of representatives in the Enterobacteriaceae family}; Babkov VV et al.; A method based on a lower sensitivity of S forms to colicines, in comparison with R forms, was used for the selection of S forms of bacteria from dissociated cultures of E . coli O.124:K72, S . sonnei, and S . flexneri . The cultures are inoculated in nutrient agar from the external segment of the zone of bacterial growth suppression by colicines D, E1, and V+m, where the content of S forms is relatively higher at the expense of death of R forms . The content of S forms in the resultant cultures of different strains was 1.7 to 31.1 times higher that in the initial cultures.

FEMS Immunol Med Microbiol, 1995 Mar, 11(1), 5 - 12
Anti-bacteroides lipopolysaccharide IgG levels in healthy adults and sepsis patients; Allan E et al.; Members of the genus Bacteroides greatly outnumber enterobacteria in the human colon and therefore represent a vast potential pool of biologically active LPS . An enzyme-linked immunosorbent assay was developed to estimate the distribution of IgG levels to LPS from B . fragilis, B . vulgatus, B . thetaiotaomicron and to a mixture of rough LPS from three enterobacteria and Pseudomonas aeruginosa in sera from 641 adult blood donors . By inhibition ELISA some cross-reactivity was demonstrated between the different anti-bacteroides LPS IgG, but with very little between the anti-bacteroides LPS IgG and the anti-enterobacterial/Pseudomonas LPS IgG . Serum IgG was measured daily over 5-9 day periods in 12 sepsis patients (6 survivors, 6 non-survivors) and in a healthy individual . In all patients IgG levels fluctuated to a greater extent than levels in a healthy subject . Variations all followed similar overall trends and indicated that exposure to bacteroides LPS had occurred . In 5 out of 6 survivors, IgG levels were rising at the end of the period, while 4 of the 6 non-survivors showed falls, with an exception showing increasing levels to B . fragilis LPS . In 5 out of 6 non-survivors, IgG levels against B . fragilis LPS were substantially higher than those against the other LPSs . In this small sample some trends in antibody kinetics have been recognised which suggest bacteroides LPS may be significant in sepsis, and indicate that this study should be extended.

J Med Microbiol, 1995 Mar, 42(3), 181 - 5
Influence of various immunosuppressive agents on the occurrence of endogenous bacteraemia in mice; Hirakata Y et al.; The influence of six immunosuppressive agents on the occurrence of endogenous bacteraemia in mice was evaluated . The mortality rates in conventional ddY mice given cyclophosphamide (CY), fluorouracil (5-FU), methotrexate (MTX), cisplatin (CDDP) or FK-506 intraperitoneally, or dexamethasone (DXM) subcutaneously were 70, 100, 100, 100, 0 and 0%, respectively . Pseudomonas aeruginosa was isolated from 70% of mice treated with CY but from only 10% of mice treated with 5-FU and 30% treated with MTX . Enterobacteria were isolated from 90% of mice treated with 5-FU . Specific-pathogen-free (SPF) mice fed P . aeruginosa were also treated with these agents . All mice in the CY, 5-FU, MTX and CDDP groups died whereas mice treated with DXM and FK-506 showed 20% and 0% mortality, respectively . Pure cultures of P . aeruginosa were obtained from all of the mice treated with CY . Polymicrobial bacteraemia with P . aeruginosa and enterobacteria occurred in 5, 25, 5 and 5% of mice treated with 5-FU, MTX, CDDP and DXM, respectively . Enterobacterial bacteraemia was observed in 70% of mice treated with CDDP and in 5% of the DXM group . Different types of bacteraemia were induced by different immunosuppressive agents . The mechanism of immunosuppression may affect the frequency of bacteraemia and the causative organism.

Proc Natl Acad Sci U S A, 1995 Feb 28, 92(5), 1664 - 8
A genetic locus of enterocyte effacement conserved among diverse enterobacterial pathogens; McDaniel TK et al.; Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E . coli O157:H7 are intestinal pathogens that profoundly damage the microvilli and subapical cytoskeleton of epithelial cells . Here we report finding in EPEC a 35-kbp locus containing several regions implicated in formation of these lesions . DNA probes throughout this locus hybridize to E . coli O157:H7 and other pathogens of three genera that cause similar lesions but do not hybridize to avirulent members of the same species . The EPEC locus and a different virulence locus of uropathogenic E . coli insert into the E . coli chromosome at the identical site and share highly similar sequences near the point of insertion.

Vet Rec, 1995 Feb 18, 136(7), 169 - 72
A survey of the incidence of Salmonella species and Enterobacteriaceae in poultry feeds and feed components; Veldman A et al.; Between July 1990 and April 1991 the rate of contamination with Salmonella species of poultry feeds and feed components used by the Dutch feed industry was surveyed . Ten per cent of 360, 10 g samples of poultry feeds were found to be contaminated . Mash feeds, mostly used for layer-breeders, were far more frequently (21 per cent) contaminated than pelleted feeds (1.4 per cent) . The rate of contamination of 130 samples of fish meal was 31 per cent, of 83 samples of meat and bone meal 4 per cent, 58 samples of tapioca 2 per cent and of 15 samples of maize grits 27 per cent . Twenty-eight serotypes of salmonellae were isolated, but no Salmonella enteritidis was found, despite the occurrence of an epidemic in poultry caused by this serotype since 1987 . The serotypes isolated most frequently were not the same as those encountered in poultry flocks . The Enterobacteriaceae isolated from the feedstuffs were predominantly thermotrophic . They were shown to be useful markers of the rate of contamination with salmonellae and of the efficiency of decontamination of the feedstuffs by pelletisation.

Schweiz Med Wochenschr, 1995 Feb 11, 125(6), 201 - 6
{Antibiotic treatment of urinary tract infections in hospitalized children}; Bianchetti MG et al.; From 1980 to 1991 237 patients (aged 1 week to 15 years) with moderate to severe urinary tract infection had been treated at the Department of Pediatrics University of Berne, Switzerland . Bacterial etiology, antimicrobial in vitro susceptibility tests, and drug management were retrospectively analyzed . 266 bacterial pathogens were isolated from these patients . Escherichia coli was the most frequent etiologic agent (203), followed by Enterococcus (21), Klebsiella (20), Proteus (12), Pseudomonas (6), Enterobacter (2) and Serratia (2) . The overall in vitro susceptibility of these isolates was 61% for aminopenicillins, 80% for co-amoxiclav, 83% for co-trimoxazole and 92% for aminoglycosides . Aminoglycosides were ineffective in vitro only against enterococci . However, since all enterococcal strains were always sensitive to aminopenicillins, none of the pathogens was concomitantly resistant to both aminoglycosides and aminopenicillins . Parenteral therapy had been given initially in 141 patients (59%); aminopenicillin and aminoglycoside in 105, and aminopenicillin alone in 36 cases (cefuroxime instead of aminopenicillin in some patients with suspected allergy to penicillin) . 96 patients (41%) were initially treated with oral antibiotics (cotrimoxazole, aminopenicillin or co-amoxiclav) . The initial antimicrobial regimen had to be modified in 31 cases (13%) . In children with moderate to severe urinary tract infection prompt sterilization of urine and kidneys will prevent or suppress renal tissue lesions . The in vitro susceptibility results observed in the pathogens isolated in the patients prompt us to suggest that the above mentioned goal can only be achieved by an initial regimen consisting of an aminopenicillin and an aminoglycoside compound administered parenterally.

Adv Ther, 1995 Mar-Apr, 12(2), 83 - 101
The selection and use of cephalosporins: a review; Klein NC et al.; Cephalosporins are among the most frequently prescribed antibiotics as a result of their broad spectrum of microbiologic activity, favorable pharmacokinetics, low incidence of adverse reactions, and proven clinical efficacy for a wide variety of infections . Cephalosporins differ in their gram-positive, gram-negative, and anaerobic spectra, serum half-lives, penetration of the cerebrospinal fluid, and resistance to beta-lactamases . The first-generation and some second-generation agents maintain excellent activity against streptococci and staphylococci, while the third-generation agents have expanded gram-negative coverage . Two third-generation cephalosporins, ceftazidime and cefoperazone, are active against Pseudomonas . Ceftizoxime has become the workhorse third-generation cephalosporin . The fourth-generation agent cefepime provides excellent activity against gram-positive and gram-negative pathogens, including antibiotic-resistant Enterobacteriaceae . A major dilemma facing the practitioner is how to select the "right" cephalosporin for a particular patient, as no one drug will satisfy all clinical needs . This review describes a practical approach to selecting an appropriate cephalosporin for common infectious disease problems.

J Trop Med Hyg, 1995 Feb, 98(1), 25 - 8
Antibiotic availability and multiresistant coliforms in a rural Ugandan hospital; Murdoch DA et al.; Twenty-seven strains of coliforms (Enterobacteriaceae) isolated at Kisiizi Hospital, Uganda, were tested for their sensitivity to antibiotics . Sixteen of the 18 patient strains were identified as Escherichia coli, but biochemical analysis, serotyping, plasmid profile and antibiogram showed them to be heterogeneous . Resistance was very common to the antibiotics available in the community (ampicillin, chloramphenicol, tetracycline and trimethoprim), but was much less frequent for the agents used only in the hospital (gentamicin, ciprofloxacin and nitrofurantoin) . A correlation was noted between the presence of large plasmids (150 kb or larger) and resistance to amoxicillin in patient strains of E . coli . The nine strains of coliform from the water supply were more heterogeneous and less resistant . The availability of antibiotics in the community seems linked to the development of multiresistant coliforms, which in a Ugandan context are very difficult to treat, and even more difficult to prevent.

J Bacteriol, 1995 Feb, 177(3), 799 - 804
Identification and characterization of an outer membrane protein, OmpX, in Escherichia coli that is homologous to a family of outer membrane proteins including Ail of Yersinia enterocolitica; Mecsas J et al.; We previously reported that a region of the Escherichia coli chromosome at 18 min increased E sigma E activity when cloned in multicopy (J . Mecsas, P . E . Rouviere, J . W . Erickson, T . J . Donohue, and C . A . Gross, Genes Dev . 7:2618-2628, 1993) . In the present report, we identify and characterize the gene responsible for the increase in E sigma E activity . This gene is in a monocistronic operon with two promoters and a rho-independent terminator . Sequence analysis of this gene indicated that it encodes an outer membrane protein which is 83% identical to OmpX in Enterobacter cloacae, leading us to name this gene ompX . There are four other proteins that are homologous to OmpX . Several of these proteins, Ail of Yersinia enterocolitica and Rck and PagC of Salmonella typhimurium, have properties that allow bacteria to adhere to mammalian cells, survive exposure to human serum, and/or survive within macrophages . We therefore characterized strains deleted for ompX for their growth phenotypes, E sigma E activity, serum resistance, and adherence to mammalian cells . No differences in growth rates, serum resistance, or adherence to mammalian cells were observed; however, E sigma E activity was dependent on expression of OmpX in certain strain backgrounds.

Ann Intern Med, 1995 Feb 1, 122(3), 179 - 86
Continuous aspiration of subglottic secretions in preventing ventilator-associated pneumonia; Valles J et al.; OBJECTIVE: To determine whether continuous subglottic aspiration prevents nosocomial pneumonia in mechanically ventilated patients . DESIGN: A randomized, controlled, blinded study . SETTING: Medical-surgical intensive care unit . PATIENTS: 190 patients who were admitted to the intensive care unit during a 33-month period and whose condition suggested the need for prolonged intubation (> 3 days) . INTERVENTION: 76 patients were randomly allocated to receive continuous aspiration of subglottic secretions, and 77 control patients were allocated to receive usual care . MEASUREMENTS: The numbers of cases of ventilator-associated pneumonia, ventilated days, days in intensive care unit, and deaths were recorded . The amount of subglottic secretions aspirated daily and surveillance cultures in the subglottic secretions were also obtained periodically . Etiologic diagnosis was based on the quantitative culture of secretions obtained by protected specimen brush or bronchoalveolar lavage . RESULTS: The incidence rate of ventilator-associated pneumonia was 19.9 episodes/1000 ventilator days in the patients receiving continuous aspiration of subglottic secretions and 39.6 episodes/1000 ventilator days in the control patients (relative risk, 1.98; 95% CI, 1.03 to 3.82) . This difference was due to a significant (P < 0.03) reduction in the number of gram-positive cocci and Haemophilus influenzae organisms in the patients receiving continuous aspiration . However, no differences were observed in the number of Pseudomonas aeruginosa or Enterobacteriaceae organisms . Episodes of ventilator-associated pneumonia occurred later in patients receiving continuous aspiration (12.0 +/- 7.1 days) than in the control patients (5.9 +/- 2.1 days) (P = 0.003) . The same microorganisms isolated from protected specimen brush or bronchoalveolar lavage cultures in patients with ventilator-associated pneumonia were previously isolated from cultures of subglottic secretions in 85% of cases . No significant differences in outcome were found . CONCLUSIONS: The incidence of nosocomial pneumonia in mechanically ventilated patients can be significantly reduced by using a simple method that decreases the chronic microaspirations through the cuff of endotracheal tubes.

East Afr Med J, 1995 Feb, 72(2), 116 - 20
Bacteraemia in patients presenting with fever; Petit PL et al.; In three studies, in Ghana and Kenya, blood from 639 patients admitted with fever was cultured . Standard treatments were antimalarials (54-100%) and antibiotics (39-90%) . According to the criteria in use, however, only 10-31% had malaria alone; of those who received antibiotics, 66% were diagnosed with malaria, gastrointestinal infections, post-operative recuperations, circulatory problems, central nervous system disorders or FUO, and did not need antibiotics at the first encounter . For those with wounds and abscesses (8%), generalised antibiotic treatment can also be questioned . Bacteraemia was found in 71 (11.3%) patients; in the HIV patients, however, 5 (23%) of 22 had bacteraemia . This is a minimum incidence, since culture techniques were not optimal for the isolation of fastidious microorganisms . The most prevalent organisms isolated were Salmonella, Klebsiella/Enterobacter and S . aureus . Resistance (intrinsic and extrinsic) in the Gram- bacteria was high: 31-100% were resistant to amoxycillin, 0-80% to cotrimoxazole, 15-95% to chloramphenicol and 9-15% to gentamicin . The need for cultures and sensitivity tests for patients with prolonged or undiagnosed fever is stressed . Specific treatment should be given only when infections, whether malarial or bacterial, have been positively diagnosed.

Mol Microbiol, 1995 Feb, 15(3), 553 - 9
AmpD, essential for both beta-lactamase regulation and cell wall recycling, is a novel cytosolic N-acetylmuramyl-L-alanine amidase; Jacobs C et al.; In enterobacteria, the ampD gene encodes a cytosolic protein which acts as a negative regulator of beta-lactamase expression . It is shown here that the AmpD protein is a novel N-acetylmuramyl-L-alanine amidase (E.C.3.5.1.28) participating in the intracellular recycling of peptidoglycan fragments . Surprisingly, AmpD exhibits an exclusive specificity for substrates containing anhydro muramic acid . This anhydro bond is mainly found in the peptidoglycan degradation products formed by the periplasmic lytic transglycosylases and thus might behave as a 'recycling tag' allowing the enzyme to distinguish these fragments from the newly synthesized peptidoglycan precursors . The AmpD substrate (or substrates) which accumulates in the absence of the corresponding enzymatic activity acts as an intracellular positive effector for beta-lactamase expression and might represent an element of a communication network between the chromosome and the cell wall peptidoglycan.

J Hosp Infect, 1995 Feb, 29(2), 135 - 42
Infection after colorectal surgery: a randomized trial of prophylaxis with piperacillin versus sulbactam/piperacillin . West of Scotland Surgical Infection Study Group; Stewart M et al.; Antibiotics used for prophylaxis in elective colorectal surgery should be effective against the organisms contaminating the soft tissues and isolated from postoperative infections . These are usually the enterobacteriaceae commensal to the colon . However, staphylococcal and anaerobic infections are not uncommon . Piperacillin has been used as antibiotic prophylaxis and been shown to be as efficacious as an aminoglycoside with metronidazole . Piperacillin is susceptible to many beta-lactamases and we have therefore conducted a study to assess the efficacy of adding sulbactam, a beta-lactamase inhibitor, to piperacillin for prophylaxis in elective colorectal surgery . Three hundred and seventy-nine patients were randomized to receive a single dose of piperacillin 4 g intravenously (iv) (group P, n = 192) or piperacillin 4 g with sulbactam 2 g iv (group SP n = 187) . Fifty-three patients were withdrawn from analysis leaving 168 evaluable patients in group P and 158 patients in group SP . Postoperative infective complications occurred in 91 (28%) patients, 55 (33%) in group P and 36 (23%) in group SP (chi 2 = 4.0 P < 0.05) . Surprisingly Staphylococcus aureus was isolated from wound infections in 22 patients (12 in group P and 10 in group SP) which represents 24% of those patients who developed infective morbidity . We conclude that sulbactam improves the efficacy of piperacillin as prophylaxis in elective colorectal surgery but does little to protect against staphylococcal wound infection.

Insect Mol Biol, 1995 Feb, 4(1), 15 - 22
Mycetome endosymbionts of tsetse flies constitute a distinct lineage related to Enterobacteriaceae; Aksoy S et al.; Tsetse flies (Diptera: Glossinidae) harbour two morphologically different endosymbionts intracellularly associated with gut tissue: a primary (P) and a secondary (S) organism . The P-endosymbiont is a gram-negative rod, 8-10 microns in size, and resides intracellularly within specialized cells, mycetocytes which are organized into an organelle (mycetome), in the anterior portion of the gut . The S-endosymbiont is a smaller (1-2 microns) gram-negative rod and is harboured in the epithelial sheath cells in midgut . Phylogenetic characterization of S-endosymbionts from taxonomically distant insects including tsetse flies has shown that they are related to the free-living bacterium, Escherichia coli, and are members of the family Enterobacteriaceae within the gamma-3 subdivision of Proteobacteria . In this study, a polymerase chain reaction (PCR) based assay was designed utilizing the conserved sequences of 16S rDNA in order to phylogenetically characterize the mycetome-associated P-endosymbionts directly from tsetse mycetome tissue . Analysis from five species of flies representing the three major subgenera of genus Glossina indicates that P-endosymbionts constitute a distinct lineage within the gamma-3 subdivision of Proteobacteria . Mycetome endosymbiont phylogeny appears to parallel the classic taxonomic assignments independently developed for their insect host species . This suggests an ancient association for this symbiosis, which may have subsequently radiated with time, giving rise to the current species of tsetse flies and their modern-day endosymbionts . Based on endosymbiont phylogeny, the fusca flies constitute the most ancient subgenus, followed by the morsitans and palpalis groups.

Acta Odontol Scand, 1995 Feb, 53(1), 49 - 54
The prevalence of Staphylococcus aureus, Enterobacteriaceae species, and Candida species and their relation to oral mucosal lesions in a group of 79-year-olds in Göteborg; Ohman SC et al.; A subject sample comprising 100 persons (47 men and 53 women) 79 years of age and selected on a statistical basis (representing all persons of that age living in Goteborg) was the object of a general medical, clinical, and microbiologic study of the prevalence of microorganisms in the oral cavity known to cause opportunistic infections . A high prevalence of diseases and frequent medications were recorded among the participants . Staphylococcus aureus was present in five patients and Enterobacteriaceae species in only one individual . Candida albicans was not found in any samples from the palatal mucosa of the 25 individuals without dentures . Of 36 healthy denture wearers C . albicans was found in 9 (25%) . In 39 persons with denture stomatitis C . albicans was obtained in 11 (28%) of the samples from the mucosa, 29 (74%) from the dentures, and 10 (26%) from the angulus oris . The prevalence of S . aureus, enteric rods, and C . albicans was low in the elderly population and, when present, correlated with the presence of dentures . No association with the patients' general health or drug use was obtained.

Antimicrob Agents Chemother, 1995 Feb, 39(2), 549 - 52
Effect of inflammation on intraocular penetration of intravenous ofloxacin in albino rabbits; Gatti G et al.; The effect of inflammation on the intraocular penetration of ofloxacin was studied in 20 albino rabbits (New Zealand White) . Inflammation was induced in the left eye by inoculation of a suspension of 10(9) CFU of heat-killed Staphyloccus epidermidis per 0.1 ml of saline solution (0.9%) in the midvitreous cavity . The other eye was kept as a control . Twenty-four hours following inoculation, ofloxacin was administered in the marginal ear vein at a dose of 15 mg/kg over 20 min with an infusion pump . Animals were sacrificed at different times up to 24 h following drug administration . Ofloxacin levels were determined in aqueous humor, vitreous humor, and serum by a bioassay . Inflammation was scored on the basis of perilimbal and corneal reactions and vitreoretinal statuses . Inflammation had a relevant effect on intraocular penetration of ofloxacin, with levels in the ocular fluids of the inflamed eye markedly exceeding the ones of the control eye . In the uninflamed eye, the levels were rapidly decaying below assay sensitivity and were no longer detectable at approximately 5 h following drug administration while they were still detectable in both ocular fluids of the inflamed eye at 24 h . Ofloxacin levels in the ocular fluids of the inflamed eye were superior to the MIC for several of the bacteria which commonly cause endophthalmitis, including Staphylococcus epidermidis, Staphylococcus aureus, most members of the family Enterobacteriaceae, Haemophilus influenzae, and strains of Pseudomonas aeruginosa.

Antimicrob Agents Chemother, 1995 Feb, 39(2), 350 - 5
Relative importances of outer membrane permeability and group 1 beta-lactamase as determinants of meropenem and imipenem activities against Enterobacter cloacae; Cornaglia G et al.; The roles of outer membrane permeability and Bush group 1 beta-lactamase activity in determining Enterobacter cloacae susceptibility to either meropenem or imipenem were investigated . A beta-lactamase-deficient strain was obtained by mutagenesis from a clinical isolate of E . cloacae, and a porin-deficient strain was selected from this mutant with cefoxitin . Both strains were transformed with the plasmid pAA20R, which contained the gene coding for the carbapenem-hydrolyzing CphA beta-lactamase, and the carbapenem permeability coefficients were measured by the Zimmermann and Rosselet technique (W . Zimmermann and A . Rosselet, Antimicrob . Agents Chemother . 12:368-372, 1977) . The permeability coefficient of meropenem was roughly half that of imipenem in the normally permeable strain and almost seven times lower than that of imipenem in the porin-deficient strain . In the porin-deficient strain, the virtual absence of porins caused the MICs of meropenem to increase from 8 to 16 times, while it did not affect the MICs of imipenem . Conversely, the beta-lactamase affected imipenem but not meropenem activity: meropenem showed a similar activity in the parent strain and in the beta-lactamase-deficient mutant with both a low- and high-density inoculum, whereas imipenem was 16 times less active against the parent strain when the high-density inoculum was used . It is concluded that outer membrane permeability and stability to group 1 beta-lactamase have different impacts on the activities of meropenem and imipenem against E . cloacae.

Am J Vet Res, 1995 Feb, 56(2), 188 - 92
Cortical bone concentrations of enrofloxacin in dogs; Duval JM et al.; Cortical bone concentrations of enrofloxacin were determined over time in dogs after SC administration of the drug . Nineteen healthy adult dogs were anesthetized and were given 2.5 or 5.0 mg of enrofloxacin/kg of body weight, SC . Serial serum and bone samples were obtained for determination of enrofloxacin concentrations at intervals until 8 hours after drug administration . Cortical bone samples were procured by surgical disarticulation of successive second phalanges . Additional cortical bone samples were taken from long bones in 4 dogs . Mean +/- SD peak serum enrofloxacin concentration was 0.54 +/- 0.10 micrograms/ml for the 2.5 mg/kg dosage and 0.97 +/- 0.34 micrograms/ml for the 5.0-mg/kg dosage . Serum concentration was significantly higher than bone concentration for each dosage . Mean peak bone concentrations reached 29% of peak serum values: 0.15 +/- 0.09 micrograms/g and 0.29 +/- 0.09 micrograms/g for 2.5-mg/kg and 5.0-mg/kg dosages, respectively . Serum concentration for the 5.0-mg/kg dosage was significantly greater than that for the 2.5-mg/kg dosage for all times, whereas bone concentrations for the 5.0-mg/kg dosage were significantly higher at all times after 180 minutes . For the duration of the study, cortical bone concentrations of enrofloxacin at either dosage exceeded the minimum inhibitory concentration (MIC) for the Enterobacteriaceae, but reliably exceeded the MIC for Staphylococcus sp only at the 5.0-mg/kg dosage.(ABSTRACT TRUNCATED AT 250 WORDS)

J Clin Microbiol, 1995 Feb, 33(2), 364 - 70
Comparison of Crystal Enteric/Nonfermenter system, API 20E system, and Vitek AutoMicrobic system for identification of gram-negative bacilli; Robinson A et al.; A comparative evaluation of the Crystal Enteric/Nonfermenter system (Crystal; Becton Dickinson, Cockeysville, Md.), API 20E (API; bioMerieux Vitek, Inc., Hazelwood, Mo.), and the Vitek GNI card (Vitek; bioMerieux Vitek) was performed with 512 clinical isolates of gram-negative bacilli, including 381 members of the family Enterobacteriaceae and 131 nonenteric bacilli . With supplemental testing, API, Crystal, and Vitek correctly identified to the genus and species level 505 (98.6%), 489 (95.5%), and 494 (96.5%) of the 512 isolates, respectively . Supplemental testing, as specified by the manufacturer, was required to identify 119 (23.2%), 18 (3.5%), and 5 (1.0%) of the isolates with the three systems, respectively . Of the 381 isolates from the family Enterobacteriaceae, API and Crystal correctly identified 90.3 and 91.6% by 18 to 24 h without supplemental testing, respectively, and Vitek identified 92.4 and 96.1% following 10 and 18 h of incubation, respectively . Of the 131 nonenteric organisms, API and Crystal correctly identified 28.2 and 93.9% by 18 to 24 h without supplemental testing, respectively, and Vitek identified 84.0% by 10 h and 93.9% by 18 h . Errors in identification with each system were infrequent and appeared to be randomly distributed among the genera evaluated . The three systems were comparable in accuracy when either a weighted clinical laboratory profile of organisms or a group of selected isolates in a stress test sample was evaluated (P > 0.05) . There were no significant differences between the three systems in their ability to identify either the isolates in the weighted group or those in the stress test (P > 0.05) . Crystal compared favorably with API and Vitek, which have established track records in clinical laboratories, and is acceptable for the identification of members of the Enterobacteriaceae and nonenteric bacilli in a clinical microbiology laboratory.

J Clin Microbiol, 1995 Feb, 33(2), 313 - 7
Comparison of BacT/Alert with Signal blood culture system; Rohner P et al.; The BacT/Alert (Organon Teknika Corp., Durham, N.C.) is an automated blood culture system . It is based on the detection of CO2 by means of a colorimetric sensor internally attached to the bottom of culture bottles . The aerobic and anaerobic media of this system were compared with one bottle of the Signal system (Oxoid Ltd., Hampshire, United Kingdom) . At bedside, 20 ml of blood was drawn from each adult patient . The two BacT/Alert bottles were inoculated with 5 ml of blood each; the Signal bottle was inoculated with 10 ml . A total of 5,284 sets (2,483 patients; 2.1 cultures per patient) consisting of three bottles each were evaluated, of which 781 sets (14.8%) revealed microorganisms (n = 892); 642 of these were considered to be pathogenic . Significantly more (P < 0.0001) pathogens were isolated from the two BacT/Alert bottles together (n = 584) than from the single Signal bottle (n = 515) . Escherichia coli (P = 0.007), gram-negative bacteria other than members of the family Enterobacteriaceae or Pseudomonas spp . (P = 0.006), and yeasts (P = 0.02) were isolated more often from both or either BacT/Alert bottle . Comparing the systems in terms of 388 different organisms per septic episode, the difference between BacT/Alert and Signal was significant for the total number of septicemia cases (P = 0.003) . More contaminants grew in the BacT/Alert system (173 versus 116; P = 0.0001) . False-positive indications were more frequent in the BacT/Alert system, 198 (3.7%) aerobic bottles and 57 (1.1%) anaerobic bottles, than in the Signal bottles, 24 (0.5%) bottles . Pathogens could be detected significantly earlier (P < 0.0001) in the BacT/Alert system than in the Signal system . The BacT/Alert instrument with two bottles allowed earlier detection as well as the isolation of more microorganisms than the manual, one-bottle Signal system.

Enferm Infecc Microbiol Clin, 1995 Feb, 13(2), 80 - 4
{Presentation, diagnosis and treatment of pyogenic liver abscess: analysis of a series of 63 cases}; Corbella X et al.; BACKGROUND: The aim of this study was to know the clinical, etiopathogenic and microbiologic characteristics of pyogenic liver abscesses (PLA) . METHODS: A retrospective analysis of the cases of PLA diagnosed from 1978 to 1992 in the Internal Medicine, Infectious Disease, and Gastrointestinal Surgery Departments of the Hospital de Bellvitge in Barcelona, Spain was performed . RESULTS: A total of 63 cases of PLA (43 males and 20 females, mean age 54 +/- 19 years) were analyzed . The most frequent clinical and analytical data included fever (92%), leucocytosis (84%) and abnormal levels of alkaline phosphatase (81%) . The PLA were single in 65% and multiple in 35% . Echography was diagnostic in 91% of the cases . A positive culture of the abscess was obtained in 40 cases, being monomicrobial in 27 cases (67.5%) . Eleven of the 13 polymicrobial cultures were from single PLA . The most frequent bacteria found were the enterobacteria (44%) followed by the microaerophilic streptococci (28%) and the anaerobes (17%) . The PLA was of biliary origin in 31.8%, contiguous in 12.7% and unknown in 38% . Percutaneous drainage was performed in 34 patients (54%) . Mortality attributable to the abscess was 3% . CONCLUSIONS: The clinical presentation of pyogenic liver abscess has not varied over time . There has, however, been a change with respect to its epidemiology and therapeutic management . At present, the possibility of rapid diagnosis and image guided percutaneous drainage offers a better prognosis for this disease.

Unfallchirurgie, 1995 Feb, 21(1), 50 - 3
{Microbial sensitivity spectrum of framycetin . Comparison with the 1972 to 1993 resistance status}; Knothe H et al.; Framycetin was tested against a variety of isolates of grampositive and gramnegative bacteria . The in-vitro activity of Framycetin against Staphylococcus aureus, Enterobacteriaceae, Pseudomonas aeruginosa as well as Pseudomonas fluorescens is today still favourable.

Res Microbiol, 1995 Feb, 146(2), 175 - 82
Shedding of antibiotic-resistant members of the family Enterobacteriaceae in healthy residents of France and Jordan; Chachaty E et al.; We compared the frequency of shedding of members of the family Enterobacteriaceae resistant to ampicillin, tetracycline, chloramphenicol, kanamycin, gentamicin and ceftazidime in 83 French residents of the Paris urban area and in 101 subjects in Jordan, 64 of whom resided in the urban area of Irbid, 15 in rural areas, and 22 of whom had a nomadic lifestyle . There was no significant difference between these populations regarding (i) the percentages of subjects with strains resistant to any of the antimicrobial agents tested and (ii) the proportions of total counts of organisms of the Enterobacteriaceae resistant to these agents . The simultaneous shedding of strains resistant to ampicillin, chloramphenicol, tetracycline and kanamycin was significantly associated with (i) exposure to antibiotic treatment during the six months preceding the study and (ii) the presence of many children at home.

Res Microbiol, 1995 Feb, 146(2), 167 - 74
Results of passive and active immunization directed against ferric aerobactin in experimental enterobacterial infections in mice and chickens; Le Roy D et al.; Production of aerobactin has been reported to be a virulence factor in members of the family Enterobacteriaceae . To investigate the protection afforded by humoral immunity directed towards aerobactin in infectious diseases caused by aerobactin-producing strains, we tested the efficacy of mAbAERO1, a murine monoclonal antibody directed to ferric aerobactin, which, in vitro, was found to impair the growth of aerobactin-dependent strains of Enterobacteriaceae under iron-limited conditions . The mortality of mice experimentally infected with the aerobactin-producing strains Escherichia coli V2019 (LD50 = 3.5 x 10(5) CFU/mice) or Klebsiella pneumoniae Caroli (LD50 = 1.3 CFU/mice) was not reduced when 1 mg of mAbAERO1 was injected intravenously 1 h before or 1 h after bacterial challenge . Nor was mortality reduced after challenge with either E . coli V2019 or K . pneumoniae Caroli, even though the active immunization of mice with purified FeAero (ferric aerobactin) conjugated with thyroglobulin as followed by a rise in systemic anti-FeAero antibodies . Lastly, chicks born of hens immunized with FeAero showed evidence of antibody transmission towards FeAero, but were not protected when challenged with E . coli MT78, an aerobactin-producing strain highly virulent for chickens . Therefore, under the experimental conditions tested, humoral immunity against aerobactin appeared to play only a minor role in protection against infections caused by aerobactin-producing members of the family Enterobacteriaceae . However, other experimental models should be tested to confirm these observations.

J Chemother, 1995 Feb, 7(1), 8 - 11
Different biological conditions influencing bacterial adherence assay; Pessina A et al.; Adherence of bacteria to animal cells is considered the first step in the pathogenesis of many infectious diseases . The most suitable techniques developed in vitro to check the capacity of bacteria to adhere to different tissues use monolayers of established cell lines . We studied the influence of incubation time (1, 2, 3 hours), cell substrates (Hep-2, H-407) and the number of bacteria per cell (1, 10, 100, 1000) on the adherence index (number of adherent bacteria per cell determined by microscopic count) of the fimbriated Escherichia coli 454 strain, Proteus rettgeri 25 and Enterobacter cloacae 10 . The data were analyzed with different statistical methods and the results evidenced that all the conditions considered affect either the end-point of the test or the adherence index . Our observations indicate that the different methods used make it impracticable to compare many data from the literature and suggest the need to search for more homogeneity in this type of assay.

Diagn Microbiol Infect Dis, 1995 Feb, 21(2), 69 - 75
A prolonged outbreak of exfoliative toxin A-producing Staphylococcus aureus in a newborn nursery; Mackenzie A et al.; An outbreak of erythromycin-resistant, exfoliative toxin-producing Staphylococcus aureus infection in a neonatal unit is described . The organism was coagulase positive but staphyloslide negative, and this unusual phenotype facilitated early recognition of the organism in the routine laboratory . In the initial outbreak there were 77 probable or confirmed cases, with a peak attack rate of 66% . Increased infection control measures were put in place and attempts were made to identify a staff carrier . No carriers were found and the major outbreak subsided . Sporadic cases occurred over the following 10 months, until May 1992, when a colonized staffperson was discovered . She was treated and no further cases occurred . The causative organism was subjected to typing by phage, enterobacterial repetitive intergenic consensus sequence polymerase chain reaction, and pulsed-field gel electrophoresis with two separate enzymes . The phage typing and genomic tests confirmed the presence of the same clone in the unit for 9 months . The organism possessed genes encoding exfoliative toxin A as determined by polymerase chain reaction.

Diagn Microbiol Infect Dis, 1995 Feb, 21(2), 105 - 10
Antimicrobial activity of 11 newer and investigational drugs tested against aerobic isolates from spontaneous bacterial peritonitis; Sader HS et al.; The in vitro susceptibility of 124 aerobic bacterial pathogens isolated from patients with spontaneous bacterial peritonitis (SBP) were tested against 11 antimicrobial agents, including parenteral or oral cephalosporins and fluoroquinolones . Most SBP isolates were Gram-negative organisms, and Escherichia coli and Klebsiella pneumoniae were responsible for 63% of the episodes evaluated . The fluoroquinolones (ciprofloxacin and ofloxacin) and the "fourth-generation" cephalosporin cefpirome were the most active agents against the Gram-negative bacteria . Commonly used cefotaxime and cefotaxime-desacetylcefotaxime (DES-CTX) combinations were also very active against Gram-negative bacteria with only few Enterobacter cloacae isolates being resistant (minimum inhibitory concentrations > 32 micrograms/ml) . All streptococci were susceptible to cefotaxime, cefpirome, and cefdaloxime and to the cefotaxime-DES-CTX combinations, whereas only ofloxacin demonstrated acceptable activity against the enterococci . The widest spectrum of activity versus SBP isolates was found for ofloxacin (98% susceptibility) among the fluoroquinolones . For the beta-lactams, the widest spectrum of activity was demonstrated by cefpirome and the 2:1 cefotaxime-DES-CTX combination (93% susceptibility) . These results indicate that the role of ofloxacin and newer parenteral or orally administered cephalosporins in the treatment of prophylaxis of SBP should be further evaluated.

Eur J Epidemiol, 1995 Feb, 11(1), 33 - 8
Molecular characterization of trimethoprim resistance in salmonellas isolated in Sicily, 1985-1988; Agodi A et al.; The occurrence of trimethoprim (Tp) resistance in salmonellas isolated from humans and water samples in Sicily between 1985 and 1988 has been investigated and the Tp resistance mechanisms have been further characterized on the basis of hybridization with probes for the dihydrofolate reductase (DHFR) genes types I, II, IV and V . Of 765 strains examined, high level (> 1000 mg/l) resistance to Tp was identified in 23 strains (3%) . In 22 of these strains, such resistance was associated with resistance to sulphonamides . Six serovars with Tp-resistant strains were identified, Salmonella typhimurium (14 strains), S . enteridis (2), S . agona (2), S . mbandaka (2), S . virchow (2), S . indiana (1) . In all strains with high level Tp resistance, resistance to this antimicrobial was plasmid-encoded, in most strains by plasmids with MWs ranging from 70-100 MDa . On the basis of restriction endonuclease analysis, four different categories of Tp resistance plasmids were identified in Tp-resistant strains of S . typhimurium . Hybridization with the DHFR I probe was observed in three strains of Tp-resistant S . typhimurium and two strains of Tp-resistant S . enteritidis; in contrast, in none of the strains tested was there any detectable hybridization with the probes for DHFR types II, IV and V . It is concluded that the DHFR type I resistance mechanism, common in Tp-resistant enterobacteria in many European countries, is relatively uncommon in Tp-resistant salmonellas isolated in Sicily . Furthermore, the DHFR V resistance mechanism, previously identified in strains of Shigella sonnei isolated in Sicily and associated with travellers from Sri Lanka, has not yet appeared in salmonellas in Sicily.

Gene, 1995 Jan 11, 152(1), 53 - 7
Conservation of cis-acting elements within the tor regulatory region among different Enterobacteriaceae; Jourlin C et al.; The Escherichia coli (Ec) torCAD operon encoding the trimethyl amine N-oxide (TMAO) reductase system is induced by both TMAO and anaerobiosis . The tor regulatory regions from bacteria related to Ec have been amplified by the polymerase chain reaction (PCR) using degenerate oligodeoxyribonucleotide primers based on conserved sequences of the tor products . The amplified regions from Salmonella enteritidis and Sa . typhimurium (St) were the same size as that from Ec and showed 82% identity with it . Interestingly, four boxes of a 10-nucleotide motif (5'-CTGTTCATAT) were found in direct repeat at the same location in the tor regulatory region of the three species . Although the amplified fragment from Shigella sonnei (Ss) was highly homologous to the Ec corresponding segment, the first tor box was missing . In Ec, the St and Ss tor promoters were still regulated by both TMAO and anaerobiosis, but their transcriptional activities were significantly lower than that of the Ec tor promoter . Deletion of the two first boxes of the Ec tor regulatory region inactivated the tor promoter while deletion of the region just upstream from the tor boxes led to a significant decrease in tor expression . Our results strongly suggest that the tor boxes, as well as specific sequences outside the tor boxes, play an important role in the expression of the tor operon.

FEBS Lett, 1995 Jan 2, 357(1), 103 - 8
Pilins of fimbrial adhesins of different member species of Enterobacteriaceae are structurally similar to the C-terminal half of adhesin proteins; Girardeau JP et al.; The structural relatedness of pilins and the C-terminal half of adhesin proteins in different member species of Enterobacteriaceae was deduced from their two-dimensional sequence analysis using the hydrophobic cluster analysis (HCA) and secondary structure predictions from the profile network Hei-Delberg program (PHD) . Despite a large evolutionary distance between the two protein families, we show that pilins and the C-terminal domain of adhesins have a similar folding that can serve as modules for pilus assembly.

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