Enterobacteriacea

Surg Today, 1999, 29(9), 963 - 5
Biliary complications after orthotopic liver transplantation in rats; Nosaka T et al.; We recently experienced a high frequency of biliary complications after orthotopic liver transplantation in rats (22 of 25 cases (88%): biloma, 20 cases; biliary peritonitis, 2 cases) . These complications seemed to be rare in general, but some researchers reported such cases and addressed them mainly through rearterialization . The biliary complications we encountered were found to be associated with necrosis of the donor bile duct and an opportunistic infection of Enterobacteriaceae . After administering appropriate antibiotics, the complications significantly diminished (2 of 25 cases (8%), P = 0.0001) . The nonarterialized bile duct, which becomes ischemic soon after liver transplantation, appears to be susceptible to infections . Such opportunistic infections may prevent the development of arterial collaterals, causing bile duct necrosis and the subsequent leakage of bile juice . When biliary complications frequently occur after nonarterialized liver transplantation in rats, the possibility of an opportunistic infection should thus be considered.

S Afr Med J, 1999 Aug, 89(8), 874 - 6
Antibiotic use and infection in snakebite victims; Blaylock RS; OBJECTIVES: To determine the incidence of infection in snakebite patients, the bacterial species involved, and the indication for antibiotics . METHOD: A prospective trial was undertaken at Eshowe Hospital, KwaZulu-Natal, involving 363 snakebite patients (records available for 310 patients) . It was protocol not to give antibiotics unless necrosis was present or anticipated . Bacterial species were identified from necrotic areas and abscesses . A swelling classification was devised . RESULTS: The syndromic presentation included no clinical envenomation (12%), painful swelling (85%), weakness (1.8%), venom ophthalmia (0.6%) and other presentations (0.6%) . There was 1 death, of an 11-year-old with gross swelling and thrombocytopenia . 15.2% of patients received antibiotics . Protocol was broken in 23 patients . None of the patients who did not receive an antibiotic became infected, and hospital stay was not prolonged in this group . Of 20 bacteria isolated, 18 were Gram-negative aerobic enterobacteriaceae . No anaerobes were cultured . CONCLUSIONS: Antibiotics should be reserved for those snakebite patients with necrosis (< 10%) and should cover Gram-negative aerobic bacilli and Gram-positive aerobic cocci.

J Med Microbiol, 1999 Sep, 48(9), 841 - 7
Phylogenetic analysis of Calymmatobacterium granulomatis based on 16S rRNA gene sequences; Kharsany AB et al.; Calymmatobacterium granulomatis is the aetiological agent of granuloma inguinale - a chronic granulomatous genital infection - and is morphologically similar to members of the genus Klebsiella . This study determined the 16S rRNA gene sequence of C . granulomatis and the taxonomic position of the organism in relation to the genus Klebsiella . Genomic DNA was extracted from C . granulomatis-infected monocytes and from frozen and formalin-fixed paraffin wax-embedded tissue biopsy specimens from patients with histologically proven granuloma inguinale . The 16S rDNA was amplified by PCR with broad range oligonucleotide primers . The amplified DNA fragments were cloned into pMOS vector, digested with Bam HI and Pst1 restriction endonucleases, hybridised with a gram-negative bacterial probe (DL04), sequenced in both directions by the automated ALF DNA sequencer, verified on an ABI Prism 377 automated sequencer and analysed with DNASIS and MEGA software packages . Sequence analysis revealed DNA homology of 99% in C . granulomatis from the different sources, supporting the belief that the bacteria in the culture and the biopsy specimens belonged to the same species, although there was some diversity within the species . Phylogenetically, the strains were closely related to the genera Klebsiella and Enterobacter with similarities of 95% and 94% respectively . C . granulomatis is a unique species, distinct from other related organisms belonging to the gamma subclass of Proteobacteria.

Scand J Infect Dis, 1999, 31(3), 287 - 91
Enterobacteriaceae meningitis in adults: a review of 20 consecutive cases 1977-97; Harder E et al.; Enterobacteriaceae are not a frequent cause of meningitis in adults and are seen mainly in neurosurgical patients and on occasion in elderly and debilitated patients . Consequently, most series studied have been small and selected . In order to obtain a clearer clinical picture, we reviewed 20 consecutive cases of Enterobacteriaceae meningitis admitted to the Department of Infectious Diseases, Rigshospitalet, Copenhagen, during the years 1977-97 . They comprised 1.5% of all cases of acute bacterial meningitis admitted to the department . All of the patients were either elderly and/or had 1 or more underlying diseases and predisposing factors . The clinical presentation and cerebrospinal fluid findings were not different from that of acute bacterial meningitis in general . The mortality rate was 40% and correlated with simultaneous bacteraemia . Complications were seen in a further 30% of patients and 25% survived with different sequelae . These high rates may, at least in part, be due to the advanced age and debilitated state of the patients studied . Escherichia coli was the most frequent of the Enterobacteriaceae.

Biosci Biotechnol Biochem, 1999 Jul, 63(7), 1261 - 8
Purification, characterization and gene analysis of N-acetylglucosaminidase from Enterobacter sp . G-1; Matsuo Y et al.; Enterobacter sp . G-1 is a bacterium isolated previously as a chitinase-producing bacterium . We found this bacterium also produced N-acetylglucosaminidase and characterized that in this study . Extracellular N-acetylglucosaminidase of 92.0 kDa was purified near homogeneity by 8.57-fold from Enterobacter sp . G-1 . The optimum temperature and the optimum pH of the purified N-acetylglucosaminidase was 45 degrees C and 6.0, respectively . The N-terminal amino acid sequence of 23 residues of N-acetylglucosaminidase was identified . Based on the N-terminal sequence, we amplified pieces of the DNA fragments by PCR . Using these PCR products as probes, we screened the genomic library and successfully isolated the entire N-acetylglucosaminidase gene (designated nag1) from Enterobacter sp . G-1 . The nucleotide sequence of the nag1 gene was found to consist of 2,655 bp encoding a protein of 885 amino acid residues . Comparison of the deduced amino acid sequence from the nag1 gene found 97.3% identity with chitobiase from Serratia marcescens, 54.4% identity with N,N'-diacetylchitobiase from Vibrio harveyi, and 42.7% identity with N-acetylglucosaminidase (ExoI) from Vibrio furnissii . Enzymatic activity assay of N-acetylglucosaminidase indicated stronger activity toward PNP-GlcNAc than PNP-(GlcNAc)2 or PNP-(GlcNAc)3.

FEMS Microbiol Lett, 1999 Aug 15, 177(2), 305 - 11
Glycosylation of the Enterobacter cloacae outer membrane protein OmpX in eukaryotic cells; de Kort G et al.; The topological model of the Enterobacter cloacae outer membrane protein OmpX showed three putative glycosylation sites . When OmpX was expressed in bacteria that were cultured under aerated conditions, no glycosylation was observed . The coupling of carbohydrate chains to the ompX gene product was also investigated in the eukaryotic baculovirus expression system . For this purpose, a recombinant ompX gene-containing baculovirus was made . Infection of insect cells with this recombinant virus resulted in the production of sufficient amounts of OmpX to study glycosylation . In this system, all potential N-glycosylation sites of OmpX were utilized . Furthermore, it became clear that glycosylated OmpX was retained in the insect cells and was not secreted in the medium . Given the fact that OmpX plays a role in the invasion of E . cloacae in rabbit enterocytes, glycosylation of this protein occurring only under specific conditions may be involved in this process.

Acta Haematol, 1999, 102(1), 7 - 11
Bacteremia by gram-negative bacilli in patients with hematologic malignancies . Comparison of the clinical presentation and outcome of infections by enterobacteria and non-glucose-fermenting gram-negative bacilli; Martino R et al.; To compare the characteristics of bacteremic infections by different aerobic gram-negative bacilli (GNB) in patients with hematologic malignancies, we studied 54 consecutive monomicrobial bacteremias by Enterobacteriaceae (EB), 15 by Pseudomonas aeruginosa, 43 by other non-glucose-fermenting GNB (NGFGNB) and 11 by other GNB . Patients with EB and P . aeruginosa bacteremia usually developed the infection after intensive chemotherapy for leukemia or during a hematopoietic stem cell transplantation, while most infections in outpatients off therapy were due to NGFGNB . A significant proportion of bacteremias by EB (37%) and P . aeruginosa (40%) were accompanied by severe morbidity (septic shock, pneumonia or deep-seated organ infections) vs . only 7% of other NGFGNB (p < 0.01) . Most infections by these latter bacteria were catheter-related bacteremias (80 vs . 2% of EB, p < 0.005), while most EB infections (61%) were uncomplicated bacteremias of unknown source (vs . 14% of other NGFGNB, p < 0.005) . Appropriate antibiotics alone cured 98% of EB and 73% of P . aeruginosa bacteremias but only 26% of other NGFGNB (p < 0.005 for both differences), which were cured by catheter removal in 70%, usually after failure of antibiotic treatment . In conclusion, our results suggest that there are significant differences in the patient populations and clinical characteristics of bacteremic infections by the classic GNB (EB and P . aeruginosa) and the new NGFGNB in adults with hematologic malignancies.

Clin Exp Immunol, 1999 Sep, 117(3), 568 - 73
Anti-lactoferrin antibodies and other types of anti-neutrophil cytoplasmic antibodies (ANCA) in reactive arthritis and ankylosing spondylitis; Locht H et al.; Fifty-five serum samples from patients with reactive arthritis (ReA), 40 from patients with ankylosing spondylitis (AS) and three from patients with chronic sacroiliac joint arthritis were analysed for the presence of ANCA of IgG class by means of enzyme immunosorbent assay using lactoferrin (Lf), myeloperoxidase (MPO) and antigen extracted from azurophil granules ('alpha-antigen') containing proteinase 3 (PR3) as substrate . IgG-ANCA were found in 31 (56%) patients with ReA . Twenty-three (42%) had anti-Lf antibodies, nine (16%) had anti-MPO and eight (15%) had anti-alpha-antigen antibodies, none of which reacted with PR3 . Only six (14%) AS or sacroiliac joint arthritis patients had ANCA (P < 0.001) . Three (7%) had anti-Lf, two (5%) anti-MPO and two (5%) anti-alpha-antigen antibodies . Yersinia and Salmonella bacteria were separated by SDS-PAGE and blots were incubated with serum from rabbits immunized with human Lf . The hyperimmune serum recognized a band of 78 kD from both bacteria which was not seen when preimmune serum was used . The reaction to the 78-kD antigen could be completely inhibited when anti-Lf antibodies were absorbed on Lf coupled to cyanogen bromide-activated Sepharose, possibly indicating cross-reacting epitopes in Lf and enterobacterial antigen.

Braz J Med Biol Res, 1999 Sep, 32(9), 1077 - 81
Phenotyping and genotyping methods applied to investigate the relatedness of Brazilian isolates of Enterobacter cloacae; Darini AL et al.; In order to evaluate the resolving power of several typing methods to identify relatedness among Brazilian strains of Enterobacter cloacae, we selected twenty isolates from different patients on three wards of a University Hospital (Orthopedics, Nephrology, and Hematology) . Traditional phenotyping methods applied to isolates included biotyping, antibiotic sensitivity, phage-typing, and O-serotyping . Plasmid profile analysis, ribotyping, and macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) were used as genotyping methods . Sero- and phage-typing were not useful since the majority of isolates could not be subtyped by these methods . Biotyping, antibiogram and plasmid profile permitted us to classify the samples into different groups depending on the method used, and consequently were not reliable . Ribotyping and PFGE were significantly correlated with the clinical epidemiological analysis . PFGE did not type strains containing nonspecific DNase . Ribotyping was the most discriminative method for typing Brazilian isolates of E . cloacae.

J Biol Chem, 1999 Sep 3, 274(36), 25260 - 5
Inhibition of the broad spectrum nonmetallocarbapenamase of class A (NMC-A) beta-lactamase from Enterobacter cloacae by monocyclic beta-lactams; Mourey L et al.; beta-Lactamases hydrolyze beta-lactam antibiotics, a reaction that destroys their antibacterial activity . These enzymes, of which four classes are known, are the primary cause of resistance to beta-lactam antibiotics . The class A beta-lactamases form the largest group . A novel class A beta-lactamase, named the nonmetallocarbapenamase of class A (NMC-A) beta-lactamase, has been discovered recently that has a broad substrate profile that included carbapenem antibiotics . This is a serious development, since carbapenems have been relatively immune to the action of these resistance enzymes . Inhibitors for this enzyme are sought . We describe herein that a type of monobactam molecule of our design inactivates the NMC-A beta-lactamase rapidly, efficiently, and irreversibly . The mechanism of inactivation was investigated by solving the x-ray structure of the inhibited NMC-A enzyme to 1.95 A resolution . The structure shed light on the nature of the fragmentation of the inhibitor on enzyme acylation and indicated that there are two acyl-enzyme species that account for enzyme inhibition . Each of these inhibited enzyme species is trapped in a distinct local energy minimum that does not predispose the inhibitor species for deacylation, accounting for the irreversible mode of enzyme inhibition . Molecular dynamics simulations provided evidence in favor of a dynamic motion for the acyl-enzyme species, which samples a considerable conformational space prior to the entrapment of the two stable acyl-enzyme species in the local energy minima . A discussion of the likelihood of such dynamic motion for turnover of substrates during the normal catalytic processes of the enzyme is presented.

J Hosp Infect, 1999 Sep, 43(1), 49 - 56
An analysis of hospital-acquired bacteraemia in intensive care unit patients in a university hospital in Kuwait; Jamal WY et al.; An analysis of hospital-acquired bacteraemia among ICU patients was carried out over a two-year period in order to determine the incidence, associated mortality rate and susceptibility pattern of causative pathogens . There was a high incidence of bacteraemia, occurring in 127 (18.4%) of 692 patients . Mortality attributable to nosocomial bacteraemia was 52% of the total 79 deaths from all causes . The highest mortality rate (58.5%) occurred in patients with fungal infections, whilst death from Gram-negative bacteraemia was only 17% . Over 98% of patients had underlying disease . Nearly half (46.8%) of 267 organisms isolated were Gram-positive . In comparison, Gram-negative bacteria accounted for 36.6% and the rest (17.6%) were fungi (mainly Candida albicans) . The majority of the bactereamic episodes were monomicrobial (90.2%) . Coagulase-negative staphylococci (CNS) were the commonest pathogens isolated, representing 32.6% of all organisms . Inducible beta-lactamase producing organism (Enterobacter spp . 9.7%, Serratia marcescens 6.7%, Klebsiella pneumoniae 6% and Pseudomonas aeruginosa 6%) formed the bulk of Gram-negative bacteria . In contrast, Escherichia coli (7.5%) and K . pneumoniae (4%) were the commonest Gram-negative bacteria from hospital-acquired bacteraemia in the general hospital population . The majority (80%) of CNS were resistant to methicillin (MRSE) but susceptible to vancomycin; they were relatively resistant to erythromycin, clindamycin and beta-lactams antibiotics . Whilst Gram-negative organisms were relatively susceptible to imipenem (85%), ciprofloxacin (88%) and amikacin (87%), they had unacceptably low levels of susceptibility to cefuroxime (59.3%), cefotaxime (71%), ceftazidime (60.9%), and piperacillin (51.1%) . This study shows that hospital-acquired bacteraemia in ICU patients carries a poor prognosis . Information regarding the infective agents and their susceptibility in the ICU setting is valuable for the selection of empirical therapy before culture and susceptibility results are known .

Transgenic Res, 1998 May, 7(3), 157 - 63
Biosafety of E . coli beta-glucuronidase (GUS) in plants; Gilissen LJ et al.; The beta-glucuronidase (GUS) gene is to date the most frequently used reporter gene in plants . Marketing of crops containing this gene requires prior evaluation of their biosafety . To aid such evaluations of the GUS gene, irrespective of the plant into which the gene has been introduced, the ecological and toxicological aspects of the gene and gene product have been examined . GUS activity is found in many bacterial species, is common in all tissues of vertebrates and is also present in organisms of various invertebrate taxa . The transgenic GUS originates from the enterobacterial species Escherichia coli that is widespread in the vertebrate intestine, and in soil and water ecosystems . Any GUS activity added to the ecosystem through genetically modified plants will be of no or minor influence . Selective advantages to genetically modified plants that posses and express the E . coli GUS transgene are unlikely . No increase of weediness of E . coli GUS expressing crop plants, or wild relatives that might have received the transgene through outcrossing, is expected . Since E . coli GUS naturally occurs ubiquitously in the digestive tract of consumers, its presence in food and feed from genetically modified plants is unlikely to cause any harm . E . coli GUS in genetically modified plants and their products can be regarded as safe for the environment and consumers.

J Antimicrob Chemother, 1999 Jul, 44(1), 113 - 6
Antimicrobial resistance patterns in urinary isolates from nursing home residents . Fifteen years of data reviewed; Vromen M et al.; The antibiotic resistance patterns of gram-negative bacteria isolated from nursing home patients between 1983 and 1997 were analysed . Escherichia coli was the most prevalent isolate (48%) followed by Proteus spp . (26%) and other Enterobacteriaceae (20%) . During the study period, the susceptibility of E . coli decreased for co-trimoxazole (79% to 62%), increased for nitrofurantoin (79% to 91%) and remained unchanged for amoxycillin (41%) . Susceptibility to norfloxacin, available from 1990, decreased from 87% to 71% . Similar trends were observed when the susceptibilities of all gram-negative urinary pathogens were combined . The changes in susceptibility can probably be attributed to the empirical prescribing practices in the nursing homes studied.

J Food Prot, 1999 Aug, 62(8), 913 - 20
Microbial shelf life determination of vacuum-packaged fresh beef treated with polylactic acid, lactic acid, and nisin solutions; Ariyapitipun T et al.; The effectiveness of polylactic acid, lactic acid, nisin, and combinations of the acids and nisin on extending the shelf-life of raw beef was determined . Fresh beef pieces (5 by 5 by 2.5 cm) were dipped in a solution of 2% low molecular weight polylactic acid (LMW-PLA), 2% lactic acid (LA), 200 IU of nisin per ml, or the combinations of nisin in either 2% LMW-PLA or 2% LA . The samples were then drip-dried, vacuum-packaged, and stored at 4 degrees C for up to 56 days . The beef surface pH values and numbers of psychrotrophic aerobic bacteria, psychrotrophic and mesophilic Enterobacteriaceae, Pseudomonas, and Lactobacillus were determined weekly for 56 days . The average surface pH values of the beef samples treated with 2% LMW-PLA or the combination of 200 IU of nisin per ml and 2% LMW-PLA were significantly reduced to 5.19 and 5.17, respectively, at day 0 (P < or = 0.05), while those decontaminated with 2% LA or 200 IU of nisin per ml in 2% LA solution were significantly decreased from 5.62 to 4.98 and 4.96, respectively . The 2% LMW-PLA, 2% LA, or the combinations of each acid and nisin showed immediate inhibitory effects on psychrotrophic aerobic bacteria (1.94, 2.36, 2.59, and 1.76 log reduction, respectively), psychrotrophic Enterobacteriaceae (1.37, 1.86, 1.77, and 1.35 log reduction, respectively), mesophilic Enterobacteriaceae (1.00, 1.00, 0.82, and 0.68 log reduction, respectively), and Pseudomonas (1.77, 1.57, 1.76, and 1.41 log reduction, respectively) on fresh beef (P < or = 0.05) . The reduction was evident up to 56 days as seen by the numbers of Enterobacteriaceae and Pseudomonas (P < or = 0.05) . Because there was no interaction between treatments and storage times, the data in each period were combined and presented as effect of treatments on overall microbial counts of fresh beef . It was found that 2% LMW-PLA, 2% LA, and the combinations of each acid and nisin significantly lowered the population of the above organisms compared with the untreated control, water, or nisin alone (P < or = 0.05).

Pharmacotherapy, 1999 Aug, 19(8 Pt 2), 120S - 128S; discussion 133S-137S
Successful interventions for gram-negative resistance to extended-spectrum beta-lactam antiobiotics; Rice LB; Antibiotic resistance among nosocomial pathogens in this country's hospitals adds significantly to patient morbidity and mortality, and the cost of health care . Optimism for identifying antimicrobial agents that would "solve the problem" of resistance has been replaced by a much more guarded and realistic view of the battle between humans and pathogenic microorganisms . Efforts now are more appropriately directed toward limiting, rather than completely eliminating, resistance, generally by either infection control or antibiotic control measures, and sometime combinations of the two . Methicillin-oxacillin resistance in Staphylococcus aureus (MRSA) results from the expression of an acquired penicillin-binding protein (PBP 2a) that is not transferable in vitro . In most hospitals, even those with high percentages of MRSA, relatively few resistant clones are identified, suggesting transmission of individual strains throughout the hospital population . Because person-to-person spread is so important in transmission of MRSA, strategies aimed at preventing transmission of the resistant strains are remarkably effective when strictly enforced . Ceftazidime resistance in Enterobacteriaceae results from point mutations within genes that encode widely prevalent and often transferable plasmid-mediated enzymes . In addition, mutations of these genes that allow hydrolysis of cephalosporins usually result in decreased activity against other drugs, including the penicillins and beta-lactamase inhibitors . Effective measures to control ceftazidime-resistant Enterobacteriaceae have as their cornerstone limiting administration of antibiotics that select for the emergence and spread of these mutations, especially ceftazidime . The importance of infection-control techniques in limiting the prevalence of ceftazidime-resistant Enterobacteriaceae is less well established . Methods that are informed by a detailed understanding of the molecular mechanisms of resistance and resistance spread offer the best hope for limiting dissemination of antibiotic-resistant bacteria in a cost-effective manner.

J Clin Microbiol, 1999 Sep, 37(9), 3029 - 30
Rapid detection of methicillin resistance in Staphylococcus aureus isolates by the MRSA-screen latex agglutination test; van Leeuwen WB et al.; The slide agglutination test MRSA-Screen (Denka Seiken Co., Niigata, Japan) was compared with the mecA PCR ("gold standard") for the detection of methicillin resistance in Staphylococcus aureus . The MRSA-Screen test detected the penicillin-binding protein 2a (PBP2a) antigen in 87 of 90 genetically diverse methicillin-resistant S . aureus (MRSA) stock culture strains, leading to a sensitivity of 97% . The three discrepant MRSA strains displayed positive results only after induction of the mecA gene by exposure to methicillin . Both mecA PCR and MRSA-Screen displayed negative results among the methicillin-susceptible S . aureus strains (n = 106), as well as for Micrococcus spp . (n = 10), members of the family Enterobacteriaceae (n = 10), Streptococcus pneumoniae (n = 10), and Enterococcus spp . (n = 10) (specificity = 100%) . Producing the same PBP2a antigen, all 10 methicillin-resistant Staphylococcus epidermidis strains score positived in both the latex test and the mecA PCR . Consequently, the MRSA-Screen test should be applied only after identification of the MRSA strain to the species level to rule out coagulase-negative staphylococci . In conclusion, due to excellent specificity and sensitivity the MRSA-Screen latex test has the potential to be successfully used for routine applications in the microbiology laboratory.

J Clin Microbiol, 1999 Sep, 37(9), 2772 - 6
PCR-Based methods for genotyping viridans group streptococci; Alam S et al.; Standard repetitive extragenic palindromic (REP)-PCR, enterobacterial repetitive intergenic consensus-PCR, and Salmonella enteritidis repetitive element-PCR methods for bacterial strain typing were performed with DNA extracted by boiling members of each of the currently recognized species of human viridans group streptococci . Each of the methods was reproducible . The unique isolates (n = 72) from 15 species of viridans group streptococci were readily distinguishable, with no two isolates showing greater than 90% per cent similarity . The majority of strains exhibited much less than 90% similarity . Isolates identical by REP-PCR were also identical by the other two methods . These PCR-based typing methods, although they do not permit determination of the species of the isolates, are simple to perform and are suitable for clinical and ecological investigations of viridans group streptococci.

Immunology, 1999 Jul, 97(3), 420 - 8
Enterobacterial infection modulates major histocompatibility complex class I expression on mononuclear cells; Kirveskari J et al.; Major histocompatibility complex (MHC) class I expression is reduced in several viral infections, but it is not known whether the same happens during infections caused by intracellular enterobacteria . In this study, the expression of MHC class I antigens on peripheral blood mononuclear cells (PBMC) from 16 patients with Salmonella, Yersinia, or Klebsiella infection was investigated . During or after the acute infection, the expression of MHC class I antigens was markedly decreased in eight patients, all with genotype HLA-B27, and six out of eight with reactive arthritis (ReA) . A significant decrease of monomorphic MHC class I was found in three patients, of HLA-B27 in eight (P<0.05) and of HLA-A2 in two . However, patients negative for the HLA-B27 genotype, or healthy HLA-B27-positive individuals, did not have a significant decrease of MHC class I antigens . During the decreased expression on the cell surface, intracellular retention of MHC class I antigens was observed, whereas HLA-B27 mRNA levels did not vary significantly . This is the first evidence that enterobacterial infection may down-regulate expression of MHC class I molecules in vivo and that down-regulation is predominant in patients with the HLA-B27 genotype.

Science, 1999 Aug 13, 285(5430), 1061 - 6
X-ray structure of the FimC-FimH chaperone-adhesin complex from uropathogenic Escherichia coli; Choudhury D et al.; Type 1 pili-adhesive fibers expressed in most members of the Enterobacteriaceae family-mediate binding to mannose receptors on host cells through the FimH adhesin . Pilus biogenesis proceeds by way of the chaperone/usher pathway . The x-ray structure of the FimC-FimH chaperone-adhesin complex from uropathogenic Escherichia coli at 2.5 angstrom resolution reveals the basis for carbohydrate recognition and for pilus assembly . The carboxyl-terminal pilin domain of FimH has an immunoglobulin-like fold, except that the seventh strand is missing, leaving part of the hydrophobic core exposed . A donor strand complementation mechanism in which the chaperone donates a strand to complete the pilin domain explains the basis for both chaperone function and pilus biogenesis.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 115 - 23
Animal models used to test the interactions between infectious agents and products of cigarette smoked implicated in sudden infant death syndrome; Sayers NM et al.; Animal test systems are reviewed that have relevance to sudden infant death syndrome (SIDS) are reviewed . These test interactions between infectious agents (or their toxins) and products of cigarette smoke . Infectious agents implicated in SIDS include members of the enterobacteria and clostridia, Staphylococcus aureus and Streptococcus pyogenes . Smoking is thought to be the single most preventable cause of SIDS . Tobacco smoke contains many extremely toxic products including cyanide and nicotine . Many animal test systems are available to examine the potency of bacterial toxins and smoke-derived components . These include mice, hamsters, rats and chick embryos . Such systems reveal synergy between bacterial toxins, especially endotoxin and superantigens . They have also demonstrated potentiation of low levels of bacterial toxin by low levels of both nicotine and its primary metabolite, cotinine . These findings suggest a possible causal explanation for the fact that passive exposure to cigarette smoke is a risk factor in sudden infant death syndrome.

FEMS Immunol Med Microbiol, 1999 Aug 1, 25(1-2), 37 - 50
Immunological evidence for a bacterial toxin aetiology in sudden infant death syndrome; Siarakas S et al.; Toxin-specific antibodies to clostridial, enterobacterial and staphylococcal toxins implicated in sudden infant death syndrome were studied in sera from sudden infant death syndrome infants and a comparison group of infants (babies with phenylketonuria) . The results indicated a higher proportion of sera from sudden infant death syndrome infants contained IgA that bound to clostridial and enterobacterial toxins but a higher proportion of sera from the phenylketonuria comparison group contained IgA that bound staphylococcal toxins . The higher proportion of serum samples with IgG and IgM in the healthy comparison babies serum probably indicated immunity in this group of babies to these toxins . The effect of gender and age had a minimal effect on the incidence of these antibodies . The presence of toxin-specific antibodies in sudden infant death syndrome and the of comparison infants suggests that all infants are exposed to these toxins and most babies successfully overcome the toxic challenge . Some infants with predisposing risk factors (temperature change, smoking, infection, immune development, sleeping position, etc.) that could affect the baby's immune competency could succumb to these and possibly other toxins . This immunological evidence further strengthens the view that bacterial toxins are a significant cause of sudden infant death syndrome.

Ophthalmology, 1999 Aug, 106(8), 1500 - 3
Microbiologic analysis of bottled water: is it safe for use with contact lenses?
Penland RL, Wilhelmus KR.
OBJECTIVE: To analyze commercially available bottled water as a possible source of microbial contamination of contact lenses . METHODS: Two different lots of 23 brands of noncarbonated bottled water were tested for coliforms, total bacteria, fungi, and free-living amebae . A sample consisted of three separate 100-ml aliquots from one lot of each brand (46 samples) . Aliquots were vacuum-filtered using a 0.45-microm Nalgene analytical filter unit, and the membrane filter was placed on a filter pad in a Petri dish containing test medium . Plates were examined under a stereomicroscope, and the number of colony-forming units (CFUs) was calculated for each sample . To test for the presence of free-living amebae, three aliquots totaling approximately 3800 ml were concentrated using 8-microm filters, and the filters were placed on non-nutrient agar with live Enterobacter aerogenes . To assess the possibility of contaminating contact lenses, etafilcon lenses were rinsed in 2-ml aliquots of four brands of bottled water and then cultured . RESULTS: Seventeen (37%) of 46 samples, representing 11 (48%) of 23 brands, contained viable micro-organisms . Bacteria, including coliforms, were recovered from 12 samples of 8 brands . Yeasts or molds were recovered from seven samples of five brands . Free-living amebae were isolated from two samples, and fresh-water algae were found in both samples of one brand . Nine (20%) of 46 samples, representing 7 (30%) of the 23 brands, had more than 500 CFUs per ml or contained coliforms . Sterile contact lenses became contaminated when exposed for 1 minute to two of four brands of water from which micro-organisms were recovered . CONCLUSION: Some bottled waters contain high numbers of potential ocular pathogens . Bottled water is not safe for routine use with contact lenses.

Eur J Clin Microbiol Infect Dis, 1999 Jun, 18(6), 414 - 21
Prevalence of aminoglycoside resistance in 20 European university hospitals participating in the European SENTRY Antimicrobial Surveillance Programme; Schmitz FJ et al.; The aim of this study was to analyse the current prevalence of aminoglycoside resistance in Europe and compare the in vitro activity of amikacin, gentamicin, and tobramycin against 7057 bacterial isolates from 20 university hospitals participating in the European SENTRY Antimicrobial Surveillance Programme . Amikacin exhibited better in vitro activity than tobramycin and gentamicin against most gram-negative bacilli in Europe . The resistance levels were 0.4-3% for amikacin, 2-13.1% for gentamicin, and 2.5-15.3% for tobramycin among different members of the family Enterobacteriaceae . Of the Staphylococcus aureus isolates tested, 75% were susceptible to gentamicin . Only 21% of all enterococcal strains tested were fully susceptible to gentamicin . Although intra-country variations in the prevalence of resistance phenotypes in Escherichia coli, Klebsiella spp., and Pseudomonas aeruginosa as well as in staphylococci and enterococci did occur, aminoglycoside resistance rates were generally higher in Italy, Portugal, Spain, Greece, France, the UK, and Poland than in Austria, Belgium, Germany, the Netherlands, and Switzerland . Compared with the 1987-88 data of the European Study Group on Antibiotic Resistance, gentamicin resistance has increased up to 5% in some gram-negative bacterial species . Furthermore, a greater than 10% increase in resistance to gentamicin has been seen in Staphylococcus aureus during the last decade . The reason for this observation is unclear, although changes in antibiotic prescribing patterns that result in increased selective pressure from gentamicin may have contributed to these increased rates of aminoglycoside resistance.

Eur J Clin Microbiol Infect Dis, 1999 Jun, 18(6), 403 - 8
Frequency of occurrence and antimicrobial susceptibility of bacterial pathogens associated with skin and soft tissue infections during 1997 from an International Surveillance Programme . SENTRY Participants Group; Jones ME et al.; The SENTRY Antimicrobial Surveillance Programme was established to provide a coordinated, standardised, international surveillance on antimicrobial resistance . In one part of the programme, isolates from skin and soft tissue infections sent from 20 hospitals in 12 different European countries were investigated in the European coordinating centre . Of 1013 isolates, Staphylococcus aureus and Pseudomonas aeruginosa were the most significant species, constituting almost 50% of the referred isolates . Methicillin resistance in Staphylococcus aureus averaged 22% across Europe, only slightly less than that in isolates derived from blood . Less than 5% of the enterococcal isolates were resistant to vancomycin . Piperacillin/tazobactam was the most active penicillin-derived beta-lactam compound against Pseudomonas aeruginosa, inhibiting 91.3% of the isolates, while ceftazidime and cefepime were the most active cephalosporins, inhibiting 85.8% and 80.3% of the isolates, respectively . Putative extended-spectrum beta-lactamase production was not detected in Escherichia coli and was found in only 5.1% of the Klebsiella pneumoniae isolates . In general, strains of the family Enterobacteriaceae remained mostly susceptible to carbapenems, cefepime, and amikacin.

Biochemistry, 1999 Aug 10, 38(32), 10499 - 510
On the importance of a methyl group in beta-lactamase evolution: free energy profiles and molecular modeling; Bernstein NJ et al.; beta-Lactam antibiotics are generally thought to inhibit their target enzymes, the bacterial cell wall-synthesizing DD-peptidases, because of their resemblance to D-alanyl-D-alanine peptides . Although a favorable conformation of the latter does structurally resemble the beta-lactams with respect to backbone conformation, a significant difference is the presence of a D-methyl substituent on the penultimate alanine residue of the cell wall peptide . A classical beta-lactam antibiotic has a hydrogen in the corresponding position . In the process of evolution of a beta-lactamase from a DD-peptidase, it seems likely that this D-methyl group would be selected against, to ensure that the former enzyme would hydrolyze beta-lactams rather than peptides . In this paper, the effect of the penultimate D-alanine residue (as opposed to a glycine residue) has been examined in peptide substrates of a present-day DD-peptidase and a beta-lactamase . The peptides N-(phenylacetyl)-D-alanyl-D-phenylalanine and N-(phenylacetyl)glycyl-D-phenylalanine were used as a test pair against the DD-peptidase of Streptomyces R61 and the structurally very similar class C beta-lactamase of Enterobacter cloacae P99 . The kinetics of turnover of both of these substrates were determined for both enzymes . To quantify the partitioning of the acyl-enzyme intermediate, the aminolysis by D-phenylalanine of a cognate pair of depsipeptides was also studied . Thus, free energy-reaction coordinate diagrams were constructed for turnover of both peptides by both enzymes . Comparison of these profiles showed that the D-methyl group is preferred over hydrogen by the DD-peptidase at all stages of catalysis (acyl-enzyme and acylation and deacylation transition states), whereas the beta-lactamase selects against the D-methyl group only at the peptide acylation transition state . A process of evolution by uniform dissociation of the methyl group by the beta-lactamase has apparently occurred . These results were explored structurally by computational models of the acylation tetrahedral intermediates . A methyl group pocket on the DD-peptidase, less favorable on the beta-lactamase, was identified . The interaction of the leaving group, the terminal D-alanine residue, with the two enzymes was interesting, since it seemed that different positively charged active site residues were directly associated with the carboxylate, Lys 315 in the beta-lactamase and Arg 285 (rather than His 298) in the case of the DD-peptidase . The problems posed by larger substituents on the penultimate residue of the peptide, and in particular by the heterocyclic substituent present in a bicyclic beta-lactam, were analyzed . Qualitative and quantitative analysis of the models support the proposed importance of the penultimate D-alanine in beta-lactamase evolution.

Biochemistry, 1999 Aug 10, 38(32), 10256 - 61
Structure of the extended-spectrum class C beta-lactamase of Enterobacter cloacae GC1, a natural mutant with a tandem tripeptide insertion; Crichlow GV et al.; A class C beta-lactamase from a clinical isolate of Enterobacter cloacae strain GC1 with improved hydrolytic activity for oxyimino beta-lactam antibiotics has been analyzed by X-ray crystallography to 1.8 A resolution . Relative to the wild-type P99 beta-lactamase, this natural mutant contains a highly unique tandem repeat Ala211-Val212-Arg213 {Nugaka et al . (1995) J . Biol . Chem . 270, 5729-5735} . The 39.4 kDa chromosomal beta-lactamase crystallizes from poly(ethylene glycol) 8000 in potassium phosphate in space group P2(1)2(1)2 with cell dimensions a = 78.0 A, b = 69.5 A, and c = 63.1 A . The crystal structure was solved by the molecular replacement method, and the model has been refined to an R-factor of 0.20 for all nonzero data from 8 to 1.8 A . Deviations of model bonds and angles from ideal values are 0.008 A and 1.4 degrees, respectively . Overlay of alpha-carbon atoms in the GC1 and P99 beta-lactamases results in an rms deviation of 0.6 A . Largest deviations occur in a loop containing Gln120 and in the Omega loop region (200-218) where the three residues 213-215 are disordered . Possibly as a result of this disorder, the width of the opening to the substrate binding cavity, as measured from the 318-324 beta-strand to two loops containing Gln120 and Tyr150 on the other side, is 0.6-1.4 A wider than in P99 . It is suggested that conformational flexibility in the expanded Omega loop, and its influence on adjacent protein structure, may facilitate hydrolysis of oxyimino beta-lactams by making the acyl intermediate more open to attack by water . Nevertheless, backbone atoms in core catalytic site residues Ser64, Lys67, Tyr150, Asn152, Lys318, and Ser321 deviate only 0.4 A (rmsd) from atoms in P99 . A rotation of a potential catalytic base, Tyr150, relative to P99 at pH 8, is consistent with the requirement for a lower than normal pK(a) for this residue.

APMIS, 1999 Jul, 107(7), 703 - 8
An evaluation of susceptibility testing methods for ampicillin-sulbactam using a panel of beta-lactamase-producing bacteria; Siu LK et al.; Bacteria possessing TEM-1-like beta-lactamases are generally regarded as susceptible to ampicillin-sulbactam (SAM), while those harboring OXA-1 enzymes are considered resistant . The current study was undertaken to compare susceptibility testing using various combinations of ampicillin and sulbactam to improve clinical correlation . Members of the Enterobacteriaceae family harboring TEM-1, SHV-1 or OXA-1-like beta-lactamases were tested using the agar dilution method . A substantial proportion of strains harboring OXA-1-like beta-lactamases showed false susceptibility to SAM at the 1:1 ratio or fixed sulbactam concentration of 8 microg/ml . At a fixed sulbactam concentration of 4 microg/ml, the activity of ampicillin-sulbactam appeared to be reduced, with large numbers of TEM-1 producers becoming frankly resistant . Results obtained with the 2:1 ratio exhibited the closest correlation with that obtained by the currently recommended disk diffusion test . However, very major errors were still found between the disk diffusion test and agar dilution test, suggesting the necessity for consideration of a change in criteria for interpretation of disk diffusion test results . In conclusion, SAM susceptibility testing by agar dilution using other than a 2:1 ratio is not recommended and results should be interpreted with caution.

Zhonghua Nei Ke Za Zhi, 1997 Aug, 36(8), 540 - 2
{The antibacterial activity of cefmetazole and other antibiotics to 463 isolates}; Xu Y et al.; We compared the in-vitro antibacterial activity of cefmetazole and other 4 antibiotics against clinical isolates . The minimal inhibitory concentration (MIC) of cefmetazole against 463 isolates was determined by standard (NCCLS) agar dilution testing, and compared with that of cefazolin, cefuroxime, cefotaxime and ceftazidime . The results showed that cefmetazole was the most effective in 5 antibiotics to indole (+)P . vulgaris and M . morganii (MIC(90) 8 mg/L), and cefmetazole had the same activity as cefotaxime (sensitive 82%-100%), but less activity than ceftazidime (sensitive 88%-100%) against E . coli, K . pneumoniae and P . morabilis . To oxacillin-sensitive staphylococci, cefmetazole was highly active, with the MIC 90 of 4 mg/L . Our results indicate that cefmetazole is highly active against Enterobacteriaceae and oxacillin-sensitive staphylococci.

Medicina (B Aires), 1999, 59 Suppl 1, 8 - 16
{In vitro activity of trovafloxacin, of other fluoroquinolones and of related antimicrobials against clinical isolates . Grupo colaborativo WHONET-Argentina}; Rossi A et al.; The in vitro activity of trovafloxacin (TRV) has been evaluated in comparison with that of other antimicrobial agents against 5671 clinical isolates recovered by representative institutions of different provinces in our country . The resistance percentage to gentamicin and third generation cephalosporins among enterobacteriaceae was high: 17% and 16% respectively, with a considerable variation according to the analyzed species . The resistance to ciprofloxacin (CIP) and TRV affected approximately 9% of the isolates, without significant differences between both drugs . Fluoroquinolones (FQ) presented excellent activity on 166 isolates of Salmonella spp., 208 of Shigella flexneri and 76 of Shigella sonnei, where only one S.sonnei isolate was resistant to CIP, but susceptible to TRV . About half the isolates of Salmonella spp . and S.sonnei and almost all S.flexneri isolates were resistant to ampicillin, and more than 60% of Shigella spp . isolates were resistant to trimethoprim-sulfamethoxazole . A 41% of Staphylococcus aureus and 55% of coagulase-negative staphylococci isolates were resistant to oxacillin, presenting a highly associated multi-resistance . The resistance to FQ was also strongly related to oxacillin resistance, but the resistance to TRV was significantly lower than the CIP resistance: 9% vs 57% for S.aureus and 4% vs 41% for coagulase-negative staphylococci . A similar behavior was observed with Enterococcus spp., where 54% of the isolates were resistant to norfloxacin and only 13% were resistant to TRV . Neither Streptococcus pneumoniae (n = 193) nor Haemophilus influenzae (n = 139) isolates presented resistant to TRV.

Eur J Ophthalmol, 1999 Apr-Jun, 9(2), 120 - 4
Bacteriological profile of ophthalmic infections in an Israeli hospital; Mezer E et al.; AIM: To find the optimal antibiotic treatment for ophthalmic infections in an Israeli hospital . METHODS: In a retrospective study from our laboratory, which serves as both a primary and secondary referral center, we analyzed the bacteriological profile and the antibiotic sensitivity of ophthalmic infections using the computerized laboratory reports of 331 consecutive ophthlamic bacteriological cultures from patients with various ophthalmic infections . RESULTS: Microbiological growth was obtained in 113 samples (34.1%) . The most commonly isolated organism was coagulase-negative staphylococcus (19.5%), followed by coagulase-positive staphylococcus (16.8%), Enterobacteriaceae (14.2%), Pseudomonas aeruginosa (13.3%), and streptococcal species (8.9%) . Pseudomonas species were the most common isolates from the lacrimal pathways (20.0%) . Streptococci were the most common isolates cultured from the conjunctiva (27.3%) . Coagulase-positive staphylococcus was the most common isolate from corneal ulcers (33.3%), and coagulase-negative staphylococcus from the vitreous (30.8%) . The overall antibiotic sensitivity of common ophthalmic pathogens was similar to that reported from other parts of the world . CONCLUSIONS: Although essentially similar to previous series, this report from the Middle East differs as follows . Firstly, Pseudomonas species were the most common isolates from the lacrimal pathways . Secondly, the overall rate of streptococcal isolates was lower than in previous reports . Thirdly, streptococcal species were rarely isolated from corneal samples . Although other studies from the region have described the causative organisms of ocular infections in specific ocular sites, this is the first study from the Middle East to summarize the full bacteriological profile of ocular infections in one medical center.

Lett Appl Microbiol, 1999 Jul, 29(1), 37 - 41
Colicin V can be produced by lactic acid bacteria; McCormick JK et al.; Colicin V is a small, proteinaceous bacterial toxin, produced by many strains of Escherichia coli and other members of the Enterobacteriaceae, that fits the definition of class II bacteriocins of Gram-positive bacteria . Export of colicin V is dependent on specific ABC (ATP-binding cassette) secretion proteins which recognize a double-glycine-type leader peptide on the immature colicin V bacteriocin . Replacement of the colicin V leader peptide by a signal peptide from the signal sequence-dependent bacteriocin divergicin A allowed expression of colicin V in lactic acid bacteria . This system may serve as a model for the heterologous expression of other small bacteriocins active against Gram-negative bacteria and other antibacterial peptides from lactic acid bacteria.

J Appl Microbiol, 1999 Jul, 87(1), 131 - 40
Culture-independent quantification of physiologically-active microbial groups in fermented foods using rRNA-targeted oligonucleotide probes: application to pozol, a Mexican lactic acid fermented maize dough; Ampe F et al.; Nine phylogenetic oligonucleotide probes were used to describe at the genus level the microbial community responsible for the spontaneous fermentation of maize, leading to the production of Mexican pozol . Ribosomal RNAs of specific groups and genera, in particular, lactic acid bacteria, were quantified using a culture-independent approach . In the early stage of the fermentation, Lactococcus and Leuconostoc appeared to be the dominant genera . A contrario, these represented minor genera at the end of the fermentation when Lactobacillus dominated the process . In addition, eukaryotes seemed to play a significant role throughout the fermentation and enterobacteria could be detected by this method.

J Chir (Paris), 1999 Mar, 136(1), 15 - 20
{Antibiotic treatment of peritonitis}; Chalfine A et al.; Secondary peritonitis usually results from perforation of a digestive tract organ . The bacterial contamination depends on the site of the perforation (supra or infra mesocolic) and the clinical setting (community or nosocomial) . Although bacteriological specimens have not been proven to be diagnostic in community-acquired peritonitis, they are nevertheless mandatory in the nosocomial setting due to the multiresistant nature of the pathogens . Experimental models have evidenced a biphasic course in peritonitis with microbial synergism between aerobic and anaerobic pathogens . These experimental studies have also evidenced the importance of treating enterobacteria and strict anaerobic pathogens . The treatment of community-acquired peritonitis should be targeted against Gram negative bacilli, strict anaerobic germs and enterococci . Resistant Gram negative bacilli and enterococci are the target bacteria for nosocomial peritonitis . Doses should be adapted to renal function and hemodynamic conditions using antibiotics with proven efficacy on susceptibility tests . The theoretical duration of treatment is a question of debate and should be adapted to each individual case.

Antimicrob Agents Chemother, 1999 Aug, 43(8), 2069 - 73
TEM-24 produced by four different species of Enterobacteriaceae, including Providencia rettgeri, in a single patient; Marchandin H et al.; Four species of members of the family Enterobacteriaceae harboring extended-spectrum beta-lactamase (ESBL) were recovered in a single patient hospitalized in an intensive care unit . Among these isolates, we describe for the first time an ESBL-producing Providencia rettgeri strain . Bacteria from the same species were shown to be genetically related by pulsed-field gel electrophoresis analysis . These strains produced the same TEM derivative ESBL, characterized as TEM-24 . This enzyme had the peculiarity of being encoded by a large conjugative plasmid of 180 kb, never previously described for such an ESBL.

Antimicrob Agents Chemother, 1999 Aug, 43(8), 2051 - 5
Comparative in vitro activities of ciprofloxacin, clinafloxacin, gatifloxacin, levofloxacin, moxifloxacin, and trovafloxacin against Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes clinical isolates with alterations in GyrA and ParC proteins; Brisse S et al.; The in vitro activities of ciprofloxacin, clinafloxacin, gatifloxacin, levofloxacin, moxifloxacin, and trovafloxacin were tested against 72 ciprofloxacin-resistant and 28 ciprofloxacin-susceptible isolates of Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Enterobacter aerogenes . Irrespective of the alterations in GyrA and ParC proteins, clinafloxacin exhibited greater activity than all other fluoroquinolones tested against K . pneumoniae and E . aerogenes.

Appl Environ Microbiol, 1999 Aug, 65(8), 3458 - 63
Production of acylated homoserine lactones by psychrotrophic members of the Enterobacteriaceae isolated from foods; Gram L et al.; Bacteria are able to communicate and gene regulation can be mediated through the production of acylated homoserine lactone (AHL) signal molecules . These signals play important roles in several pathogenic and symbiotic bacteria . The following study was undertaken to investigate whether AHLs are produced by bacteria found in food at temperatures and NaCl conditions commercially used for food preservation and storage . A minimum of 116 of 154 psychrotrophic Enterobacteriaceae strains isolated from cold-smoked salmon or vacuum-packed chilled meat produced AHLs . Analysis by thin-layer chromatography indicated that N-3-oxo-hexanoyl homoserine lactone was the major AHL of several of the strains isolated from cold-smoked salmon and meat . AHL-positive strains cultured at 5 degrees C in medium supplemented with 4% NaCl produced detectable amounts of AHL(s) at cell densities of 10(6) CFU/ml . AHLs were detected in cold-smoked salmon inoculated with strains of Enterobacteriaceae stored at 5 degrees C under an N(2) atmosphere when mean cell densities increased to 10(6) CFU/g and above . Similarly, AHLs were detected in uninoculated samples of commercially produced cold-smoked salmon when the level of indigenous Enterobacteriaceae reached 10(6) CFU/g . This level of Enterobacteriaceae is often found in lightly preserved foods, and AHL-mediated gene regulation may play a role in bacteria associated with food spoilage or food toxicity.

Int J Syst Bacteriol, 1999 Jul, 49 Pt 3, 941 - 51
Complex genomic and phenotypic characterization of the related species Staphylococcus carnosus and Staphylococcus piscifermentans; Pantucek R et al.; On the basis of numerical analysis of 100 phenotypic features, the strains of two species, Staphylococcus carnosus and Staphylococcus piscifermentans, were differentiated into two separate phenons corresponding with the macrorestriction patterns of their genomic DNA, as well as with the results of ribotyping and PCR amplification of enterobacterial repetitive intergenic consensus sequences . One of the S . carnosus strains, the F-2 strain, was shown to be marginal, exhibiting the lowest genomic and phenotypic similarity to the S . carnosus type strain DSM 20501T . Two of the strains studied (strains S . carnosus SK 06 and S . piscifermentans SK 05) were phenotypically convergent, forming a separate phenon . They were phenotypically similar, even though the genomic DNA of one of them was homologous with that of the S . carnosus type strain, whereas that of the other was homologous with the genomic DNA of the S . piscifermentans type strain . In such cases, fingerprinting methods (particularly macrorestriction analysis and ribotyping) served as important correctives, as they allow phenotypically convergent strains to be distinguished on the basis of their genomic profiles . The results of this paper support the proposal for the new species Staphylococcus condimenti as well as the new subspecies Staphylococcus carnosus subsp . utilis.

Lik Sprava, 1999 Jan-Feb, (1), 33 - 5
{The use of the natural mineral saponite for water decontamination}; Hyrin VM et al.; Sorption properties were studied of natural and activated specimens of saponite with respect to poliomyelitis virus, Coxsackie B 1 and B 6 viruses as well as to Enterobacteriaceae group bacteria . With the purpose of comparing the processes of sorption of microorganisms, other minerals were also used, such as bentonite, alunite, glauconite, ceolite . The natural saponite adsorptive properties were found out to undergo changes during the process of thermoactivation . Mechanisms are discussed of a decontaminating effect of thermoactivated saponite in water.

Antonie Van Leeuwenhoek, 1999 Jan-Feb, 75(1-2), 135 - 41
Molecular genetics of carbapenem antibiotic biosynthesis; McGowan SJ et al.; Carbapenems are potent beta-lactam antibiotics with a broad spectrum of activity against both Gram positive and Gram negative bacteria . As naturally produced metabolites, they have been isolated from species of Streptomyces, Erwinia and Serratia . The latter two members of the Enterobacteriaceae have proved to be genetically amenable and a growing body of research on these organisms now exists concerning the genes responsible for carbapenem biosynthesis and the regulatory mechanisms controlling their expression . A cluster of nine carbapenem (car) genes has been identified on the chromosome of Erwinia carotovora . These genes encode the enzymes required for construction of carbapenem and the proteins responsible for a novel beta-lactam resistance mechanism, conferring carbapenem immunity in the producing host . Although sharing no homology with the well known enzymes of penicillin biosynthesis, two of the encoded proteins are apparently similar to enzymes of the clavulanic acid biosynthetic pathway implying a common mechanism for construction of the beta-lactam ring . In addition, a transcriptional activator is encoded as the first gene of the carbapenem cluster and this allows positive expression of the remaining downstream genes in response to a quorum sensing, N-acyl homoserine lactone, signalling molecule.

Eur J Clin Microbiol Infect Dis, 1999 May, 18(5), 330 - 4
Home intravenous antibiotic therapy for patients with infective endocarditis; Huminer D et al.; Although home intravenous antibiotic therapy (HIAT) is increasingly being used for various infectious diseases, outpatient treatment of infective endocarditis (IE) is still uncommon . Recently, the American Heart Association recommended outpatient treatment of endocarditis only for infections with streptococci that are highly susceptible to penicillin . Herein, the experience with HIAT in patients with IE due to a diversity of pathogens is presented . During a 3-year period, 37 patients with IE who were in a stable condition and were cooperative were enrolled in a service for HIAT after completion of diagnostic procedures . Of the 37 patients, 21 were male; mean age was 64.3 years (range 20-87 years); in most cases (26/37), IE involved a native valve . Causative organisms were Streptococcus spp . (20), Staphylococcus spp . (10), Enterococcus spp . (2), Enterobacter spp . (1), and Erysipelothrix rhusiopathiae (1), while three were unknown . The most common antibiotics used were ceftriaxone and vancomycin . Almost three-quarters of the intravenous lines were peripheral . The mean duration of HIAT was 26.2 +/- 8.5 days, with 92% of the patients cured by it . Most complications were minor . Six patients were rehospitalised and two of them required valve replacement . In half of the rehospitalised patients, the complication was unrelated to HIAT . Surprisingly, almost all of the complications necessitating rehospitalisation occurred in patients with streptococcal IE and most involved native valves . HIAT may be suitable for IE due to a diversity of pathogens and involving prosthetic as well as native heart valves, provided there are proper patient and antibiotic selections, good follow-up, and vigilant monitoring of complications.

Mikrobiologiia, 1999 Mar-Apr, 68(2), 149 - 54
{FMN-reductase from Escherichia coli and its effect on the activity of luciferase from marine bacterium Vibrio fischeri}; Mazhul' MM et al.; Interactions of luciferases isolated from Vibrio fischeri 6 and Escherichia coli JM109(pF3) (bearing cloned V . fischeri luxAB genes) with FMN reductase isolated from E . coli JM109 were studied . FMN reductase formed a stable complex with luciferase, suggesting similar properties of the FMN reductases in the taxonomically close families Vibrionaceae and Enterobacteriaceae.

J Food Prot, 1999 Apr, 62(4), 398 - 402
Biogenic amines and sensory changes associated with the microbial flora of Mediterranean gilt-head sea bream (Sparus aurata) stored aerobically at 0, 8, and 15 degrees C; Koutsoumanis K et al.; Changes in the concentrations of tyramine, agmatine, putrescine, cadaverine, spermidine, tryptamine, spermine, histamine, and trimethylamine were studied in parallel with the development of the microbial population during the storage of Mediterranean gilt-head sea bream (Sparus aurata) at three temperatures (0, 8, 15 degrees C) . Changes in sensory scores were also recorded . Pseudomonads and H2S-producing bacteria were the dominant microorganisms . Enterobacteriaceae and lactic acid bacteria were also present in the fish microflora . Among the biogenic amines, putrescine and cadaverine were detected when pseudomonads exceeded 10(6) to 10(7) CFU/g . Histamine was produced only in samples stored at 15 degrees C . Tyramine, tryptamine, agmatine, and trimethylamine were absent regardless of the storage temperature.

Int J Antimicrob Agents, 1999 Jul, 12(2), 129 - 34
Selection of resistant variants of respiratory pathogens by quinolones; Sefton AM et al.; Quinolones are widely used in the treatment of respiratory tract infections . However, some disquiet has been expressed over using quinolones for community-acquired pneumonia since their activity is generally rather poor against Streptococcus pneumoniae . In addition, it is known that resistant variants emerge at a fairly high frequency during exposure of Enterobacteriaceae to quinolones; if this also occurred during quinolone treatment of community-acquired pneumonia it could lead to an increased risk of clinical failure . We therefore determined the selection rate of quinolone-resistant variants for six strains of S . pneumoniae, Haemophilus influenzae and Moraxella catarrhalis with nalidixic acid (except for S . pneumoniae), ciprofloxacin, ofloxacin and levofloxacin . We were only able to select resistant variants at low frequency from two of the six strains of S . pneumoniae with ciprofloxacin: no resistant variants were selected by either ofloxacin or levofloxacin . Variants of H . influenzae and M . catarrhalis with decreased susceptibility to quinolones were produced both with more strains and with a greater frequency; however, these variants still remained susceptible according to the NCCLS guidelines . Our study suggests that resistant variants of S . pneumoniae are relatively unlikely to occur in individuals treated with fluoroquinolones especially if they are given quinolones with enhanced anti-gram-positive activity compared to ciprofloxacin.

FEMS Microbiol Lett, 1999 Jul 1, 176(1), 11 - 5
Penetration of beta-lactamase inhibitors into the periplasm of gram-negative bacteria; Farmer TH et al.; The effectiveness of a beta-lactamase inhibitor/beta-lactam combination against Gram-negative pathogens depends on many interplaying factors, one of which is the penetration of the inhibitor across the outer membrane . In this work we have measured the relative penetrations of clavulanic acid, sulbactam, tazobactam and BRL 42715 into two strains of Escherichia coli producing TEM-1 beta-lactamase, two strains of Klebsiella pneumoniae producing either TEM-1 or K-1, and two strains of Enterobacter cloacae each producing a Class C beta-lactamase . It was shown that clavulanic acid penetrated the outer membranes of all these strains more readily than the other beta-lactamase inhibitors . For the strains of E . coli and K . pneumoniae clavulanic acid penetrated approximately 6 to 19 times more effectively than tazobactam, 2 to 9 times more effectively than sulbactam and 4 to 25 times more effectively than BRL 42715 . The superior penetration of clavulanic acid observed in this study is likely to contribute to the efficacy of clavulanic acid/beta-lactam combinations in combating beta-lactam resistant bacterial pathogens.

Pathol Biol (Paris), 1999 May, 47(5), 437 - 9
Emergence of multidrug-resistant Enterobacter cloacae: nosocomial outbreak or change of microbial ecology?
Honderlick P, Saheb F, Cahen P.
Frequent selection of mutants resistant to extended and broad spectrum cephalosporins in Enterobacter cloacae is observed in hospital . As we noticed an unusual number of isolates of these strains and to answer the question arose whether these Enterobacter had a common source, we retrospectivally studied 56 strains collected in 11 wards of the hospital . Using PFGE with Spe 1 restriction analysis we identified a prevalent clone (11 patients) dispatched in 8 wards . We also obviously proved cross-contamination patients to patients with other clones . PFGE allow us to point out that clonal Enterobacter cloacae has taken place in our hospital, even if there is no real outbreak . A reinforcement of basic hygienic measures and a control of antibiotics prescription seemed very important to jugulate the sudden increase of multiresistant Enterobacter cloacae prevalence.

Mol Microbiol, 1999 Aug, 33(3), 590 - 8
Na+ translocation by the NADH:ubiquinone oxidoreductase (complex I) from Klebsiella pneumoniae; Krebs W et al.; Complex I is the site for electrons entering the respiratory chain and therefore of prime importance for the conservation of cell energy . It is generally accepted that the complex I-catalysed oxidation of NADH by ubiquinone is coupled specifically to proton translocation across the membrane . In variance to this view, we show here that complex I of Klebsiella pneumoniae operates as a primary Na+ pump . Membranes from Klebsiella pneumoniae catalysed Na+-stimulated electron transfer from NADH or deaminoNADH to ubiquinone-1 (0.1-0.2 micromol min-1 mg-1) . Upon NADH or deaminoNADH oxidation, Na+ ions were transported into the lumen of inverted membrane vesicles . Rate and extent of Na+ transport were significantly enhanced by the uncoupler carbonylcyanide-m-chlorophenylhydrazone (CCCP) to values of approximately 0.2 micromol min-1 mg-1 protein . This characterizes the responsible enzyme as a primary Na+ pump . The uptake of sodium ions was severely inhibited by the complex I-specific inhibitor rotenone with deaminoNADH or NADH as substrate . N-terminal amino acid sequence analyses of the partially purified Na+-stimulated NADH:ubiquinone oxidoreductase from K . pneumoniae revealed that two polypeptides were highly similar to the NuoF and NuoG subunits from the H+-translocating NADH:ubiquinone oxidoreductases from enterobacteria.

Arch Latinoam Nutr, 1999 Mar, 49(1), 76 - 80
{Microbiological quality of pasteurized milk creams manufactured in Venezuela}; Szwarcbort de Tamsut L et al.; A total of 100 samples of pasteurized milk creams produced by eleven (11) dairy milk industries were analyzed for the presence of microoganisms . The dairy milk industries were distributed along different places of Venezuela . The samples were analyzed for the presence of mesophilic aerobic bacteria, psychotropic bacteria, Staphylococcus aureus, coliformes, molds and yeasts 75% of the analyzed samples did not reach the international standards for aerobic mesophilic bacteria, similarly, 95% for Staphylococcus aureus, 91% for coliformes and 58% for molds and yeasts, so pathogenic enterobacteria we have found: Salmonella Typhimurium, Shigella sonnei and Escherichia coli enteropathogenic.

Pneumologie, 1999 Apr, 53(4), 199 - 206
{Inpatient treatment costs of exacerbated chronic obstructive lung disease}; Riecke K et al.; Economic aspects are of increasing importance in health care . However, treatment expenditures for most diseases are unknown . We performed a detailed cost analysis for the treatment of the exacerbated chronic obstructive pulmonary disease (ECOPD) in our department . For one year, all patients admitted because of exacerbated chronic obstructive pulmonary disease were included in this study . The workload was assessed for each patient by time keeping . Diagnostic and therapeutic procedures were considered according to the price list of the German hospital association . From 101 patients included into the study, 100 were evaluable . The median duration of inpatient hospitalisation amounted to 18 days (range: 4 to 210 days) . Median total cost was DM 7680.- and mean cost DM 11900.- . This consisted of non-medical cost items (36%), personnel expenditures (29%), laboratory tests (14%), respiratory and cardiovascular laboratory (7%), radiology (5%) and pharmacy cost (7%) . Endoscopy, external diagnostics and medical reports amounted to 2.8% of the expenditure . Treatment cost correlated with the duration of stay, but hardly with lung function and blood gases, these being independent of age and sex, but significantly higher in case of bronchiectasis, enterobacteriae, cor pulmonale or intensive care . The proportion of the pharmacy expenditures was rather small, and hence this is not a primary target for the realisation of major savings.

J Clin Microbiol, 1999 Aug, 37(8), 2488 - 92
Value of enterobacterial repetitive intergenic consensus PCR for study of Pasteurella multocida strains isolated from mouths of dogs; Loubinoux J et al.; Fifty-six Pasteurella multocida strains (40 P . multocida subsp . septica and 16 P . multocida subsp . multocida strains) isolated from the mouths of 56 dogs among the 134 living in a French canine military training center (132e Groupe Cynophile de l'Armee de Terre, Suippes, France) were studied by use of enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) and restriction fragment length polymorphism (RFLP) techniques . Both techniques showed genomic heterogeneity of the strains studied . However, RFLP was more discriminatory than ERIC-PCR for differentiating P . multocida strains . All but three pairs of strains were discriminated by RFLP, suggesting a limited circulation of strains between these dogs living in proximity . Although ERIC-PCR is easier and faster to perform, it cannot be recommended for epidemiological studies of P . multocida strains.

J Clin Microbiol, 1999 Aug, 37(8), 2473 - 8
Comparison of molecular methods for typing Vibrio parahaemolyticus; Marshall S et al.; An outbreak of Vibrio parahaemolyticus gastroenteritis on Canada's west coast in 1997 emphasized the need to develop molecular methods for differentiation and typing of these organisms . Isolates were analyzed by enterobacterial repetitive intergenic consensus sequence (ERIC) PCR, detection of restriction fragment length polymorphisms (RFLP) in rRNA genes (ribotyping), pulsed-field gel electrophoresis (PFGE), and RFLP analysis of the genetic locus encoding the polar flagellum (Fla locus RFLP analysis) . ERIC PCR and ribotyping were the most informative typing methods, especially when used together, while Fla locus RFLP analysis was the least discriminatory . PFGE exhibited good discrimination but suffered from a high incidence of DNA degradation . ERIC PCR and ribotyping will be useful for the evaluation of genetic and epidemiological relationships among V . parahaemolyticus strains.

Arch Pharm Res, 1999 Jun, 22(3), 274 - 8
Expression of the recombinant Klebsiella aerogenes UreF protein as a MalE fusion; Kim KY et al.; Expression of the active urease of the enterobacterium, Klebsiella aerogenes, requires the presence of the accessory genes (ureD, ureE, ureF, and ureG) in addition to the three structural genes (ureA, ureB, and ureC) . These accessory genes are involved in functional assembly of the nickel-metallocenter for the enzyme . Characterization of ureF gene has been hindered, however, since the UreF protein is produced in only minute amount compared to other urease gene products . In order to overexpress the ureF gene, a recombinant pMAL-UreF plasmid was constructed from which the UreF was produced as a fusion with maltose-binding protein . The MBP-UreF fusion protein was purified by using an amylose-affinity column chromatography followed by an anion exchange column chromatography . Polyclonal antibodies raised against the fusion protein were purified and shown to specifically recognize both MBP and UreF peptides . The UreF protein was shown to be unstable when separated from MBP by digestion with factor Xa.

Pharmazie, 1999 Jun, 54(6), 460 - 3
Comparative study on the in vitro antibacterial activity of Australian tea tree oil, cajuput oil, niaouli oil, manuka oil, kanuka oil, and eucalyptus oil; Harkenthal M et al.; To compare the antibacterial activity of the Australian tea tree oil (TTO) with various other medicinally and commercially important essential myrtaceous oils (cajuput oil, niaouli oil, kanuka oil, manuka oil, and eucalyptus oil) the essential oils were first analysed by GC-MS and then tested against various bacteria using a broth microdilution method . The highest activity was obtained by TTO, with MIC values of 0.25% for Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Salmonella choleraesuis, Shigella flexneri, Bacillus subtilis, Listeria monocytogenes, Staphylococcus aureus, S . saprophyticus, and S . xylosus . It is noteworthy that manuka oil exhibited a higher activity than TTO against gram-positive bacteria, with MIC values of 0.12% . Both TTO and manuka oil also demonstrated a very good antimicrobial efficacy against various antibiotic-resistant Staphylococcus species . Pseudomonas aeruginosa was resistant to all essential oils tested, even at the highest concentration of 4%.

Arch Microbiol, 1999 Jul, 172(1), 22 - 30
Genetic basis of enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprint pattern in Sinorhizobium meliloti and identification of S . meliloti employing PCR primers derived from an ERIC-PCR fragment; Niemann S et al.; The enterobacterial repetitive intergenic consensus (ERIC)-PCR method was employed to generate genomic amplification products of Sinorhizobium meliloti strain 2011 . Eleven distinctive PCR fragments obtained in PCR reactions by using the ERIC2 primer were cloned and their partial or complete nucleotide sequences established . DNA sequences that extended past the ERIC2 primer region were not conserved among the 11 PCR fragments and showed no sequence similarity to the enterobacterial ERIC consensus sequence . Thus, repetitive ERIC or ERIC-like sequences seem not to be an integral part of the S . meliloti genome . An amplification product of S . meliloti 2011 was identified which was present in S . meliloti strains but absent in other rhizobial species . Based on the nucleotide sequence information, a pair of PCR primers was designed and used for PCR amplification of sequences of S . meliloti laboratory strains 2011, L5-30, AK631 and 102F34 . Nucleotide sequence analysis of the amplification products revealed a 100% DNA sequence conservation . Database searches showed that the DNA fragment putatively encodes the C-terminal part of a protein displaying similarity to 2-hydroxyacid dehydrogenases of various organisms . The newly designed PCR primers should be useful for the rapid identification of S . meliloti isolates.

Acta Biochim Pol, 1998, 45(4), 1011 - 9
Immunochemical studies on R mutants of Yersinia enterocolitica O:3; Radziejewska-Lebrecht J et al.; Three mutants of Yersinia enterocolitica O:3, namely: YeO3-R1, YeO3-RfbR7 and YeO3-c-trs8-R were classified on the basis of sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS/PAGE) profile of isolated lipopolysaccharides (LPS) as belonging to the Ra- (the first) and the Rc-type (the other two mutants) . Methylation analysis, in addition to 13C and 1H NMR studies of purified core oligosaccharides revealed structures similar to those established previously for the full core of Y . enterocolitica O:3 in the case of the Ra mutant, and identical to that reported for the Rc mutant Ye75R, in the case of the two other mutants . The O-specific sugar, 6d-L-altrose, which forms a homopolymeric O-chain, was present in small amounts in all three LPS preparations, as well as in the core oligosaccha ride preparations along with the Ra and the Rc sugars, characteristic of the Y . enterocolitica O:3 core . This result is in line with genetic data, indicating that it is the inner core region which is the receptor for the O-specific chain in Y . enterocolitica O:3 . This region seems likewise to be the anchoring region for the enterobacterial common antigen (ECA), as shown by SDS/PAGE/Western blot analysis with monoclonal antibodies against ECA . In addition, we also demonstrated that the Ye75R mutant Rc and its parental strain Ye75S, both were ECA-immunogenic strains . So far, ECA-immunogenic strains, i.e . those with LPS-linked ECA, were only identified in E . coli mutants of the R1, R4 and K-12 serotype.

Int J Antimicrob Agents, 1999 May, 11(3-4), 305 - 8
The prevalence of antimicrobial resistance among uropathogens causing acute uncomplicated cystitis in young women; Gupta K et al.; Four hundred and fifty-two urine isolates from women with acute uncomplicated cystitis and a positive urine culture presenting to a sexually transmitted disease clinic were collected during 1989-1991, and 213 specimens were collected over 1995-1997 . The predominant species was Escherichia coli, representing 68% of the isolates; others included Staphylococcus saprophyticus (8%), Group B streptococci (7%), Proteus spp . (6%), Klebsiella spp . (4%) and Enterococcus spp.(3%) . More than 10% of the E . coli isolates were resistant to ampicillin, cephalothin, tetracycline and trimethoprim sulfamethoxazole (TMP SMX ) during both study periods, with the greatest increase in resistance to ampicillin and TMP/SMX between the two periods . Six hundred and four urinary tract infection isolates, including 83% E . coli, 7% S . saprophyticus, 3%, Klebsiella spp . 2% Proteus spp., 2% enterococci, 1% Enterobacter spp . and 2% other organisms, were collected from women with acute cystitis attending a university student health service during 1995 . Among E . coli isolates, 25% were resistant to ampicillin, 24% to tetracycline and 11%, to TMP SMX . Resistance to fluoroquinolones was essentially absent among gram-negative pathogens . Continued evaluation of susceptibility patterns of pathogens causing acute uncomplicated cystitis to traditional as well as new antimicrobials in well defined populations is necessary to ascertain the optimal empiric therapy.

Klin Med (Mosk), 1999, 77(5), 27 - 31
{Population study of antibodies to some potential pathogens of spondyloarthopathies: the study of the Chukotka population}; Guseva IA et al.; The paper presents the results of the study of specific immune response stimulated by some enterobacteria in populations with high incidence of HLA-B27 . A, M and G antibodies to Yersinia, Clebsiella, Salmonella and Campilobacter were studied on 292 plasma samples . The levels of the antibodies varied with anthropological parameters of the examinees (gender, age, nationality) . The presence of the gene HLA-B27 in the genotype levels gender dimorphism of the specific humoral immune response . This may be of importance in pathogenesis of spondyloarthropathies which occur more frequently in men.

Proc Natl Acad Sci U S A, 1999 Jul 6, 96(14), 8110 - 5
The mast cell tumor necrosis factor alpha response to FimH-expressing Escherichia coli is mediated by the glycosylphosphatidylinositol-anchored molecule CD48; Malaviya R et al.; Mast cells are well known for their harmful role in IgE-mediated hypersensitivity reactions, but their physiological role remains a mystery . Several recent studies have reported that mast cells play a critical role in innate immunity in mice by releasing tumor necrosis factor alpha (TNF-alpha) to recruit neutrophils to sites of enterobacterial infection . In some cases, the mast cell TNF-alpha response was triggered when these cells directly bound FimH on the surface of Escherichia coli . We have identified CD48, a glycosylphosphatidylinositol-anchored molecule, to be the complementary FimH-binding moiety in rodent mast cell membrane fractions . We showed that (i) pretreatment of mast cell membranes with antibodies to CD48 or phospholipase C inhibited binding of FimH+ E . coli, (ii) FimH+ E . coli but not a FimH- derivative bound isolated CD48 in a mannose-inhibitable manner, (iii) binding of FimH+ bacteria to Chinese hamster ovary (CHO) cells was markedly increased when these cells were transfected with CD48 cDNA, and (iv) antibodies to CD48 specifically blocked the mast cell TNF-alpha response to FimH+ E . coli . Thus, CD48 is a functionally relevant microbial receptor on mast cells that plays a role in triggering inflammation.

Biochem J, 1999 Jul 15, 341 ( Pt 2), 409 - 13
Peptidase activity of beta-lactamases; Rhazi N et al.; Although beta-lactamases have generally been considered as being devoid of peptidase activity, a low but significant hydrolysis of various N-acylated dipeptides was observed with representatives of each class of beta-lactamases . The kcat/Km values were below 0.1 M(-1) . s(-1), but the enzyme rate enhancement factors were in the range 5000-20000 for the best substrates . Not unexpectedly, the best 'peptidase' was the class C beta-lactamase of Enterobacter cloacae P99, but, more surprisingly, the activity was always higher with the phenylacetyl- and benzoyl-d-Ala-d-Ala dipeptides than with the diacetyl- and alpha-acetyl-l-Lys-d-Ala-d-Ala tripeptides, which are the preferred substrates of the low-molecular-mass, soluble dd-peptidases . A comparison between the beta-lactamases and dd-peptidases showed that it might be as difficult for a dd-peptidase to open the beta-lactam ring as it is for the beta-lactamases to hydrolyse the peptides, an observation which can be explained by geometric and stereoelectronic considerations.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1759 - 60
Sequence of the MIR-1 beta-lactamase gene; Jacoby GA et al.; The complete nucleotide sequence of the plasmid-mediated MIR-1 beta-lactamase gene confirms its relationship to chromosomally located ampC genes of Enterobacter cloacae . blaMIR-1 is not part of a typical gene cassette but does lie near an element that could be involved in its capture on a plasmid.

Antimicrob Agents Chemother, 1999 Jul, 43(7), 1743 - 6
Class C beta-lactamases operate at the diffusion limit for turnover of their preferred cephalosporin substrates; Bulychev A et al.; It has been suggested that class C beta-lactamases have evolved to carry out a metabolic reaction other than hydrolysis of beta-lactam antibiotics . It is demonstrated in the present study that the class C beta-lactamase from Enterobacter cloacae P99 has reached the diffusion limit in its ability to hydrolyze its preferred cephalosporin substrates . The increase in the solution viscosity by addition of a microviscogen (sucrose) caused the decline in the parameter kcat/Km for hydrolysis of cephaloridine and cephalosporin C (approximately 2.5-fold at a relative viscosity of 2.9) . A similar increase in viscosity has no effect on the turnover rate of the poorer substrates cefepime and penicillin G . Addition of a macroviscogen (polyethylene glycol) to the reaction mixture did not change the rate of turnover for any of the substrates tested because in this case the viscogen would not interfere with the motion of small molecules, as was expected . Therefore, it would appear that the driving force behind the evolution of this class C beta-lactamase and, in principle, other enzymes of this class is indeed the functional reaction of this enzyme as a drug resistance factor.

Int J Antimicrob Agents, 1999 Jun, 12(1), 33 - 9
In vitro activity of clinafloxacin against fluoroquinolone resistant Spanish clinical isolates; Lopez-Brea M et al.; The in vitro activity of clinafloxacin against 162 ciprofloxacin-resistant clinical isolates was determined . Isolates were selected when their MIC to ciprofloxacin was 2 mg/l (intermediate) or > 2 mg/l (resistant) . The following strains were tested: 61 Escherichia coli, 12 Klebsiella pneumoniae, 7 Proteus mirabilis, 21 Serratia marcescens, 4 Enterobacter cloacae, 21 Pseudomonas aeruginosa, 21 Staphylococcus . aureus (resistant to methicillin) and 15 Enterococcus spp . Clinafloxacin, ciprofloxacin, ofloxacin and norfloxacin activities were evaluated by agar dilution using Mueller-Hinton agar according to NCCLS recommendations . Of the 162 isolates, 16 (9.8%) were intermediate and 146 (90.1%) resistant to ciprofloxacin . 95 of the 162 strains (58.6%) were susceptible, 27 (16.7%) intermediately susceptible, and 40 strains (24.7%) were resistant to clinafloxacin . The percentage susceptible to clinafloxacin was 65.6% for E . coli, 75% for K . pneumoniae, 71.4% for P . mirabilis, 28.6% for S . marcescens, 75% for E . cloacae, 33.3% for P . aeruginosa, 90.5% for S . aureus and 40% for Enterococcus spp . Clinafloxacin was active against 58.6% of the ciprofloxacin-resistant clinical isolates tested . It was particularly active against S . aureus strains resistant to both ciprofloxacin and methicillin.

An Med Interna, 1999 May, 16(5), 236 - 8
{Urinary tract infection and antibiotic sensitivity in the south of Albacete, Spain}; Atienza Morales MP et al.; OBJECTIVES: Describing the bacteriological map of the urinary tract infections (UTI) in our area including intra and extrahospitalized patients during 1997 . MATERIAL AND METHODS: Descriptive-retrospective study, 12,937 urocultives were carried out in our laboratory: 847 from hospitalized patients and 12,090 from 15 Health Centres . RESULTS: 1,527 positive cultures (12.6%) were obteined from Health Centre patients and 215 (25.3%) from hospitalized patients . Bacterial distribution was similar between them, except enterocci and negative coagulase estafilococci which were more frequent in hospitalized patients . We have observed a high prevalence of Enterobacter sp . (4%) and Pseudomonas sp . (4%) which disagrees with other studies . E.coli (presents in 69% of the positive urocultives) was widespread resistant to quinolones, pipemidic acid and nitrofuration, while it had high sensitivity to fosfomicin, cephuroxim and amoxicilin-clavulanic acid . CONCLUSIONS: The level of resistance to the quinolones is considerable in our area, so clinicians should give them up in empirical treatment and use fosfomicine, cephuroxime or amoxicilin-clavulanic acid.

Kansenshogaku Zasshi, 1999 May, 73(5), 429 - 36
{A trial of povidone-iodine (PVP-I) nasal inhalation and gargling to remove potentially pathogenic bacteria colonized in the pharynx}; Kawana A et al.; OBJECTIVE: Aspiration of potentially pathogenic bacteria (PPB) colonized in the upper airway is a major cause of bacterial pneumonia . We hypothesized that PVP-I nasal inhalation is effective in removing PPB from the upper airway . The aim of this study was to investigate the effectiveness and safety of PVP-I nasal inhalation . METHODS: Patients with asymptomatic PPB (MRSA and/or aerobic GNB i.e . Pseudomonas aeruginosa, Enterobacteriaceae) colonization in the pharynx were enrolled in this study . These patients were divided randomly into two groups as follows: a PVP-I nasal inhalation group (N group) which was asked to inhale 1% PVP-I solution x 2/day nasally by a jet nebulizer and gargling with PVP-I solution x 2/day, and a control group (C group), which was asked to gargle with PVP-I solution x 2/day . The study period was 2 weeks in both groups . RESULTS: Group N consisted of 16 cases, which included 9 (56%) cases with chronic respiratory complications and group C consisted of 14 cases which included 6 (43%) cases with complications . In N and C group, PPB disappearance from the pharynx was observed in 44% and 14% of patients after the study period, respectively . In the patients of group N, without chronic respiratory complication, PPB disappeared in 86% ot the cases . There was no adverse effect correlated with PVP-I nasal inhalation . CONCLUSION: We conclude that PVP-I nasal inhalation is a safe procedure for removing PPB from the upper airway, and this method may contribute to preventing bacterial pneumonia.

Eur J Clin Microbiol Infect Dis, 1999 Apr, 18(4), 305 - 9
Antibacterial activity of moxifloxacin (Bay 12-8039) against aerobic clinical isolates, and provisional criteria for disk susceptibility tests; Barry AL et al.; Moxifloxacin (Bay 12-8039), ciprofloxacin, and levofloxacin were compared in vitro against 1074 clinical isolates gathered from different medical centers throughout North America during the winter months of 1997 . Moxifloxacin E tests and broth microdilution tests gave comparable results . Moxifloxacin was particularly potent against respiratory pathogens such as Haemophilus influenzae and Streptococcus pneumoniae . Ciprofloxacin was the most potent study drug against the family of Enterobacteriaceae and Pseudomonas spp . For tests of 5 microg moxifloxacin disks, zone size criteria of < or = 17 mm for resistant (MIC > or = 8 microg/ml) and > or = 21 mm for susceptible (MIC < or = 2 microg/ml) are provisionally proposed for use while clinical trials are under way.

J Antimicrob Chemother, 1999 May, 43(5), 703 - 6
In-vitro antimicrobial activity of a carbapenem, MK-0826 (L-749,345) and provisional interpretive criteria for disc tests; Fuchs PC et al.; The in-vitro activity of MK-0826, a new oral carbapenem, was compared with that of imipenem by broth microdilution susceptibility tests against 545 bacterial isolates . MK-0826 had significantly greater activity against Enterobacteriaceae and poorer activity against Pseudomonas aeruginosa and many gram-positive species . MK-0826 disc diffusion tests were also performed according to the NCCLS procedure and tentative interpretive criteria were determined for possible susceptible MIC breakpoints of < or = 4.0 and < or = 2.0 mg/L.

J Food Prot, 1999 Jun, 62(6), 615 - 8
Antimicrobial resistance of bacterial flora associated with bovine products in South Africa; Manie T et al.; The administration of subtherapeutic doses of antibiotics to livestock introduces selective pressures that may lead to the emergence and dissemination of resistant bacteria . This study determined the antibiotic-resistance spectra of the microbial flora found on freshly slaughtered and retail beef and in unpasteurized and pasteurized packaged milk . Staphylococci, Enterobacteriaeae, and isolates from total aerobic plate counts were tested for resistance to vancomycin, streptomycin, methicillin, tetracycline, and gentamicin using the disc diffusion susceptibility test and resistance to penicillin was determined by using oxacillin . A larger proportion of resistance to most antibiotics, except for vancomycin, was displayed by isolates from abattoir samples . The incidence of multiple antibiotic resistance (MAR) pathogenic bacteria is also higher in the abattoir . Resistance genes lost because of lack of selective pressure or resistant flora being replaced by more sensitive flora during processing is the reason for the lower incidence of MAR pathogenic bacteria among retail samples . These resistant bacteria can be transferred to humans through the consumption of rare or raw beef and unpasteurized milk, thus rendering the resultant food-related infections difficult to treat . The present findings clearly demonstrate that antibiotic-resistant bacteria in beef and milk pose a serious problem in South Africa.

Antibiot Khimioter, 1999, 44(3), 15 - 8
{Investigation and identification of the antimicrobial component of the drug "Tomatol"}; Vorob'ev AA et al.; Antimicrobial activity of Tomatol against laboratory strains of Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538-P and Candida albicans ATCC 885-653 as well as against clinical isolates of Enterobacter spp., Streptococcus spp., Staphylococcus spp., Klebsiella spp . and Escherichia spp . was tested . Tomatol was shown to have a broad antimicrobial spectrum including gram-positive and gram-negative organisms and Candida . The TLC investigation demonstrated that the Tomatol antimicrobial component was that of a complex of organic acids such as succinic, citric, tartaric and others.

J Antimicrob Chemother, 1999 Jan, 43(1), 119 - 26
Risk of resistance related to antibiotic use before admission in patients with community-acquired bacteraemia; Pedersen G et al.; We analysed the association of antibiotic therapy before admission and antibiotic resistance of blood isolates in a total of 1717 community-acquired bacteraemias in the County of Northern Jutland during 1992-96 . Antibiotics had been prescribed to 14% of the patients during the 30 days before admission and to 37% during the 6 months . The most frequently prescribed antibiotics within 30 days were ampicillin (28%), penicillin G (27%), sulphonamides and/or trimethoprim (16%) and macrolides (14%) . The most frequent blood isolates were Escherichia coli (33%), other Enterobacteriaceae (8%), Streptococcus pneumoniae (23%) and Staphylococcus aureus (10%) . Of the 575 isolates of E . coli, 425 (74%), 432 (75%) and 518 (90%) were susceptible to ampicillin, sulphonamides and trimethoprim, respectively . Previous antibiotic prescriptions were strongly associated with resistance to ampicillin, sulphonamides and trimethoprim in E . coli . The association was less pronounced for S . aureus and enteric rods other than E . coli . Antibiotic prescriptions within the last 3 months predicted antibiotic resistance, and this should be taken into account when selecting empirical antibiotic therapy of severe community-acquired infections.

J Antimicrob Chemother, 1999 Jan, 43(1), 71 - 7
The post-exposure response of Enterobacteriaceae to ceftibuten; MacKenzie FM et al.; The responses of ten isolates of Enterobacteriaceae to ceftibuten exposure were monitored by measuring several parameters . Post-antibiotic effect (PAE), control-related effective regrowth time (CERT) and post-antibiotic sub-MIC effect (PA-SME) were determined by bacterial enumeration carried out either by impedance in combination with viable counting (IMP/VC) or by impedance in combination with bioluminescence (IMP/BIOL) . Kill curves were carried out by bioluminescence, viable counting and direct microscopy and post-exposure morphology was established . Ceftibuten primarily provoked filamentation . Over 24 h, kill of up to 3.6 log10 was evident by viable counting and direct microscopy at and above the MIC . Minimal kill, of up to 0.26 log10, was shown by bioluminescence . PAE was found to be method dependent, with statistical differences established by Student's t-test . PAE values of up to 0.48 h and 1.47 h (by IMP/BIOL and IMP/VC respectively) were not concentration dependent above 1 x MIC . CERT values were not method dependent, with values of up to 1.71 h also showing a lack of concentration dependence above 1 x MIC . PA-SME may reflect the situation in vivo more accurately than either PAE or CERT . In PAE and CERT studies the antibiotic is eliminated almost immediately, whereas in vivo there is gradual decrease in antibiotic levels . These persisting levels are reflected more accurately by PA-SME . Compared with PAE and CERT, significantly longer values, of up to 7.27 h, were obtained by PA-SME, although this parameter was also found to be method dependent . The results of the PA-SME studies, which may be the most clinically relevant pharmacodynamic parameter, confirm the appropriateness of the current once- or twice-daily dosing schedules despite the lack of PAE.

J Antimicrob Chemother, 1999 Jan, 43(1), 55 - 60
Markedly different rates and resistance profiles exhibited by seven commonly used and newer beta-lactams on the selection of resistant variants of Enterobacter cloacae; Chan WC et al.; Seven beta-lactam antibiotics (cefepime, cefoperazone, ceftazidime, ceftriaxone, cefamandole, imipenem and meropenem) were tested for their potential to select resistance in standard and clinical strains of Enterobacter cloacae (n = 9) . The strains were subcultured daily with the test antibiotics at doubling concentrations starting at 0.125 x MIC . Development of resistance throughout the passages was detected by a disc diffusion test . Ceftazidime, ceftriaxone and cefamandole selected resistance at a faster rate than cefoperazone, cefepime and meropenem . Imipenem did not select resistance in the nine strains tested and was the only antibiotic that eradicated all the strains during selection . The resistance patterns of strains selected by meropenem, cefepime and the other cephalosporins were markedly different, although cross-resistance to the early generation cephalosporins was common . The resistance phenotypes of most strains remained stable upon serial passages in antibiotic-free medium . The findings of this study highlight the importance of the choice of antibiotic for therapy not only on the basis of its antibacterial activity, but also on its potential to select resistance to itself and other antibiotics.

Can J Microbiol, 1999 Feb, 45(2), 162 - 71
Phenol degradation by an enterobacterium: a Klebsiella strain carries a TOL-like plasmid and a gene encoding a novel phenol hydroxylase; Heesche-Wagner K et al.; Although phenol catabolism is described for many different microorganisms, there is no example for such a pathway in an enterobacterial strain . Here we characterize a Klebsiella oxytoca strain that grows on phenol as the only source of carbon and energy . As the key enzyme of phenol degradation, phenol hydroxylase was purified to apparent homogeneity . Compared with other phenol hydroxylases, the Klebsiella enzyme differs with respect to several properties: (i) SDS-PAGE and gel-filtration analysis of the purified protein revealed that the enzyme is a monomer with a molecular mass of 156 kDa; (ii) steady-state kinetic measurements resulted in a K(m) value of 0.22 mM for phenol; and (iii) the enzyme is both dependent on NADPH/FAD and sensitive to EDTA . Further degradation of catechol, the reaction product of phenol hydroxylase, may occur via the effective meta-fission pathway often located on TOL or TOL-like plasmids . Such a plasmid was prepared from the Klebsiella strain and further characterized . The given data demonstrate that the isolated strain exhibits all characteristics of an efficient phenol-degrading microorganism.

Pediatr Pulmonol, 1999 Jun, 27(6), 432 - 4
Nosocomial transmission of penicillin-resistant Streptococcus pneumoniae; Cimolai N et al.; Two patients were found to harbor intermediate-level penicillin-resistant Streptococcus pneumoniae in a pediatric hospital setting . For the first patient, the bacterium was isolated from a tracheal aspirate, and for the second patient, a positive blood culture was found a short time after the index case . Two molecular typing techniques (enterobacterial repetitive intergenic consensus sequence polymerase chain reaction, and repetitive sequence-based polymerase chain reaction) demonstrated homology among these isolates, which suggests person-to-person spread . We propose the need for institution-based infection control precautions that will limit the spread of penicillin-resistant pneumococci.

Exp Anim, 1999 Apr, 48(2), 101 - 6
Establishment of specific pathogen-free rabbit colonies with limited-flora rabbits associated with conventional rabbit flora, and monitoring of their cecal flora; Yanabe M et al.; In the present study we attempted to establish specific-pathogen-free (SPF) rabbit breeding colonies with two groups of limited-flora (LF) rabbits, both ex-germfree rabbits, and their offspring . Two groups of LF rabbits associated with cecal flora of conventional (CV) rabbits produced in a previous study {Exp . Animals, submitted}, were transferred to individual barrier rooms and some of the LF rabbits were accommodated in isolators to maintain the basic flora for SPF rabbits . The composition of the cecal flora of LF rabbits was stable for a long period; bacteroides remained predominant and clostridia dominant . From the SPF rabbits, different types of bacteria, e.g., enterobacteriaceae and streptococci, which could not be isolated in the isolator were detected at a low population level at an early stage in the establishment of the SPF colonies, but the basic composition of the cecal flora was mainly bacteroidaceae and clostridia and did not change over a long period, and the floral composition became similar to that of CV rabbits . The fertility and weaning rates of the SPF rabbits were satisfactory for a SPF rabbit colony . In addition, these SPF colonies were free of more than one year rabbit-specific pathogens.

J Clin Microbiol, 1999 Jul, 37(7), 2165 - 9
Most Enterobacter aerogenes strains in France belong to a prevalent clone; Bosi C et al.; The aim of this study was to determine the distribution in France of the Enterobacter aerogenes prevalent clone isolated in the hospitals of the Marseille area (A . Davin-Regli, D . Monnet, P . Saux, C . Bosi, R . Charrel, A . Barthelemy, and C . Bollet, J . Clin . Microbiol . 34:1474-1480, 1996) . A total of 123 E . aerogenes isolates were collected from 23 hospital laboratories and analyzed by random amplification of polymorphic DNA and enterobacterial repetitive intergenic consensus-PCR to determine their epidemiological relatedness . Molecular typing revealed that 21 of the 23 laboratories had isolated this prevalent clone harboring the plasmid encoding for extended-spectrum beta-lactamase of the TEM-24 type . Most isolates were susceptible only to imipenem and gentamicin . Their dissemination seems to be clonal and was probably the result of the general use of broad-spectrum cephalosporins and quinolones . Four isolates showed an alteration of their outer membrane proteins, causing decrease of susceptibility to third-generation cephalosporins and imipenem and leading to the critical situation of having no alternative therapeutic . The large dissemination of the E . aerogenes prevalent clone probably results from its good adaptation to the antibiotics administered in France and the hospital environment, particularly in intensive care units.

J Med Microbiol, 1999 Jun, 48(6), 559 - 67
Phenotypic and genotypic typing of food and clinical isolates of Enterobacter sakazakii; Nazarowec-White M et al.; Enterobacter sakazakii, designated a unique species in 1980, has been implicated as the causative organism in a rare but severe form of neonatal meningitis . Dried infant formula milk has been identified as a potential source of the organism . E . sakazakii isolates from dried infant formula available in Canada and clinical isolates obtained from Canadian hospital culture collections were characterised by phenotypic (biotype and antibiograms) and genotypic (ribotyping, random amplification of polymorphic DNA and pulsed-field gel electrophoresis) methods . Three biotypes and four antibiogram patterns were observed in the 18 isolates examined . Ribotyping with the Dupont Riboprinter microbial identification system divided the 18 isolates into 10 ribotypes . Three isolates from the same hospital had indistinguishable ribotyping patterns although each was isolated in a different year, as did three food isolates from one company . Pulsed-field gel electrophoresis (PFGE) and random amplification of polymorphic DNA (RAPD) profiles indicated minor differences between the isolates that were indistinguishable by ribotyping . PFGE (with the restriction endonucleases Xba1 and Spe1) and RAPD gave discrete patterns that enabled easy comparison of E . sakazakii isolates, with a high degree of discrimination . The discriminatory index showed RAPD and PFGE were shown to be the most discriminatory typing schemes for E . sakazakii, followed by ribotyping, biotyping and antibiograms.

Khirurgiia (Mosk), 1999, (5), 41 - 4
{Small intestine intubation for treatment of patients with peritonitis and intestinal obstruction}; Petrov VP et al.; The analysis of 36 case records of patients with peritonitis (n = 12) and intestinal obstruction (n = 24) is presented . Nasogastrointestinal intubation of the small bowel was used in combined treatment . The aims, indications and contraindications for the intubation are formulated . Bacteriologic and biochemical parameters of bowel content were studied . It was established that the quantity of enterobacteria and unfermenting gram-negative bacteria was increased in intestinal paresis, the alkaline phosphatase, amylase, bilirubin, transaminase, a potassium content were increased as well . For the tube to function from the first hours after its introduction it should be periodically properly washed with sodium hypochlorite in concentration 300 mg/l.

Mol Plant Microbe Interact, 1999 Jun, 12(6), 499 - 507
Mutation in a gene required for lipopolysaccharide and enterobacterial common antigen biosynthesis affects virulence in the plant pathogen Erwinia carotovora subsp . atroseptica; Toth IK et al.; Spontaneous bacteriophage-resistant mutants of the phytopathogen Erwinia carotovora subsp . atroseptica (Eca) SCRI1043 were isolated and, out of 40, two were found to exhibit reduced virulence in planta . One of these mutants, A5/22, showed multiple cell surface defects including alterations in synthesis of outer membrane proteins, lipopolysaccharide (LPS), enterobacterial common antigen (ECA), and flagella . Mutant A5/22 also showed reduced synthesis of the exoenzymes pectate lyase (Pel) and cellulase (Cel), major virulence factors for this pathogen . Genetic analysis revealed the pronounced pleiotropic mutant phenotype to be due to a defect in a single gene (rffG) that, in Escherichia coli, is involved in the production of ECA . We also show that while other enteric bacteria possess duplicate homologues of this gene dedicated separately to synthesis of LPS and ECA, Eca has a single gene.

J Microbiol Methods, 1999 May, 36(1-2), 129 - 38
Microbiological study of the dripping waters in Altamira cave (Santillana del Mar, Spain); Laiz L et al.; The culturable microbial populations in dripping waters from Altamira cave were studied and compared with those of the ceiling rock . Water communities have low proportions of gram-positive bacteria, and are mainly composed of gram-negative rods and cocci (Enterobacteriaceae and Vibrionaceae), while those of ceiling rocks are mainly Streptomyces spp . The community differences are probably related to environmental cave conditions: high humidity, relatively low and stable temperature, water pH close to neutrality and nature of the organic matter . All these factors seem to favor colonization and long-term growth of actinomycetes over other heterotrophic bacteria on ceiling rocks.

Drugs, 1999 May, 57(5), 743 - 50
Practical recommendations for the drug treatment of bacterial infections of the male genital tract including urethritis, epididymitis and prostatitis; Joly-Guillou ML et al.; Bacterial infections of the male genital tract in young men (<35 years old) are primarily caused by sexually transmissible bacteria like Chlamydia trachomatis, Neisseria gonorrhoeae but also Mycoplasma or Haemophilus spp . In men aged over 35 years, Enterobacteriaceae are more frequently involved in urethritis, epididymitis and prostatitis . The traditional treatments suggested like tetracyclines or erythromycin are less effective since bacterial resistance is increasingly frequent, particularly in N . gonorrhoeae . Moreover, patient compliance with these drug treatments are frequently not well observed . New therapies including short term therapy with fluoroquinolones or azalides (e.g . azithromycin) are very effective and easy to use and thus eliminate any problem of compliance . However, we have to be vigilant for the emergence of resistant strains to these agents.

Acta Chir Belg, 1999 Apr, 99(2), 85 - 6
Rupture of the spleen associated with Enterobacter cloacae; Peiper M et al.; A 58-year-old male, with abdominal pain but no signs of sepsis, was admitted as a medical emergency . During hospitalization, spontaneous splenic rupture was diagnosed and splenectomy successfully performed . A smear revealed presence of Enterobacter cloacae on the splenic surface; histopathology demonstrated granulocytous infiltration of the spleen.

J Antimicrob Chemother, 1999 Apr, 43(4), 497 - 501
Efficacy of beta-lactam and inhibitor combinations in a diffusion chamber model in rabbits; Georgopoulos A et al.; Using a diffusion chamber in rabbits, we evaluated therapy with the combination of ceftriaxone plus the beta-lactamase inhibitor tazobactam in comparison with ceftriaxone alone . One sensitive and one resistant strain of Escherichia coli, Enterobacter cloacae and Klebsiella pneumoniae were inoculated into one of the six diffusion chambers, implanted in the same animal . In order to simulate pharmacokinetics in humans, both substances were administered in decreasing doses . Ceftriaxone was given 0, 2, 4 and 6 h after infection in dosages of 45, 35, 25 and 15 mg/kg of body weight, while tazobactam was administered either in one dose at 0 h, or divided into two doses at 0 and 1 h or 0 and 4 h, or divided into three doses at 0, 1 and 4 h after infection . The ratio of ceftriaxone:tazobactam was fixed at 8:1 . Ceftriaxone, in combination with tazobactam, given in one dose immediately after infection showed a significant reduction in bacterial count . All other combinations of ceftriaxone and tazobactam did not differ from ceftriaxone in monotherapy . Co-administration of the beta-lactamase inhibitor tazobactam significantly enhanced the activity of ceftriaxone against all three tested species.

Appl Environ Microbiol, 1999 Jun, 65(6), 2513 - 9
Role of pfkA and general carbohydrate catabolism in seed colonization by Enterobacter cloacae; Roberts DP et al.; Enterobacter cloacae A-11 is a transposon mutant of strain 501R3 that was deficient in cucumber spermosphere colonization and in the utilization of certain carbohydrates (D . P . Roberts, C . J . Sheets, and J . S . Hartung, Can . J . Microbiol . 38:1128-1134, 1992) . In vitro growth of strain A-11 was reduced or deficient on most carbohydrates that supported growth of strain 501R3 but was unaffected on fructose, glycerol, and all amino acids and organic acids tested . Colonization by strain A-11 was significantly reduced (P </= 0.05) for cucumber and radish seeds compared to that of strain 501R3, but colonization of pea, soybean, sunflower, and sweet corn seeds was not reduced . Pea seeds released several orders of magnitude more total carbohydrates and amino acids than cucumber and radish seeds and approximately 4,000-fold more fructose . Fructose was the only carbohydrate detected in the seed exudates which supported wild-type levels of in vitro growth of strain A-11 . Soybean, sunflower, and sweet corn seeds also released significantly greater amounts of fructose and total carbohydrates and amino acids than cucumber or radish seeds . The exogenous addition of fructose to cucumber and radish seeds at quantities similar to the total quantity of carbohydrates released from pea seeds over 96 h increased the populations of strain A-11 to levels comparable to those of strain 501R3 in sterile sand . Molecular characterization of strain A-11 indicated that the mini-Tn5 kanamycin transposon was inserted in a region of the genome with significant homology to pfkA, which encodes phosphofructo kinase . A comparison of strain A-11 with Escherichia coli DF456, a known pfkA mutant, indicated that the nutritional loss phenotypes were identical . Furthermore, the pfkA homolog cloned from E . cloacae 501R3 complemented the nutritional loss phenotypes of both E . coli DF456 and E . cloacae A-11 and restored colonization by strain A-11 to near wild-type levels . These genetic and biochemical restoration experiments provide strong evidence that the quantities of reduced carbon sources found in seed exudates and the ability of microbes to use these compounds play important roles in the colonization of the spermosphere.

Diagn Microbiol Infect Dis, 1999 May, 34(1), 65 - 72
Bacterial pathogens isolated from patients with skin and soft tissue infections: frequency of occurrence and antimicrobial susceptibility patterns from the SENTRY Antimicrobial Surveillance Program (United States and Canada, 1997) . SENTRY Study Group (North America); Doern GV et al.; As part of the SENTRY Antimicrobial Surveillance Program, 1562 bacterial isolates were recovered from hospitalized patients with skin and soft tissue infections (SSTIs) in 30 United States (U.S.) and 8 Canadian medical centers between October and December, 1997 . The overall rank order of recovery of the six most common pathogens was Staphylococcus aureus (42.6%) > Pseudomonas aeruginosa (11.3%) > Enterococcus spp . (8.1%) > Escherichia coli (7.2%) > Enterobacter spp . (5.2%) > beta-hemolytic streptocci (5.1%) . With one exception, essentially the same order was observed in both the U.S . and Canada . The single exception was the Enterococcus group, which were the third most common isolate in the U.S . (9.6%), but the seventh most common isolate in Canada (3.7) . Of note, 24.0% of S . aureus isolates were oxacillin resistant; vancomycin was uniformly active . Vancomycin resistance among Enterococcus spp . (16.5%) was observed only in the U.S . Several antimicrobial agents remained broadly active for SSTI isolates of P . aeruginosa, including meropenem, amikacin, tobramycin, and piperacillin with or without tazobactam . Imipenem resistance (MICs, > or = 8 micrograms/mL) was observed in 11.9% of isolates of P . aeruginosa and ceftazidime, and cefepime had equivalent activity (85.2% and 85.8% susceptible, respectively) . Numerous beta-lactams, aminoglycosides and fluoroquinolones were broadly active against E . coli SSTI isolates (i.e . < 5% resistance) . Extended-spectrum beta-lactamase production was uncommon both with E . coli and Klebsiella spp . in both nations . Cefepime, imipenem, and meropenem; the aminoglycosides; and fluoroquinolones were conspicuously more active against Enterobacter spp . than other agents tested . High-level, stably derepressed Amp C beta-lactamase production was commonly observed in this group (26.8%), but cefepime generally retained activity against these ceftazidime-resistant organisms . The results of this study serve to define the most common bacterial causes of SSTIs in North America, elucidate patterns of antimicrobial resistance and can be used as a basis for making initial empiric antimicrobial management decisions in hospitalized patients with such infections.

Proc Natl Acad Sci U S A, 1999 May 25, 96(11), 6456 - 61
A new pathway for the secretion of virulence factors by bacteria: the flagellar export apparatus functions as a protein-secretion system; Young GM et al.; Biogenesis of the flagellum, a motive organelle of many bacterial species, is best understood for members of the Enterobacteriaceae . The flagellum is a heterooligomeric structure that protrudes from the surface of the cell . Its assembly initially involves the synthesis of a dedicated protein export apparatus that subsequently transports other flagellar proteins by a type III mechanism from the cytoplasm to the outer surface of the cell, where oligomerization occurs . In this study, the flagellum export apparatus was shown to function also as a secretion system for the transport of several extracellular proteins in the pathogenic bacterium Yersinia enterocolitica . One of the proteins exported by the flagellar secretion system was the virulence-associated phospholipase, YplA . These results suggest type III protein secretion by the flagellar system may be a general mechanism for the transport of proteins that influence bacterial-host interactions.

Pol Arch Med Wewn, 1998 Oct, 100(4), 321 - 30
{Asymptomatic bacteriuria in women diagnosed with systemic lupus erythematosus (SLE)}; Koseda-Dragan M et al.; The aims of our research were: estimation of asymptomatic bacteriuria (a.b.) incidence in population of women with systemic lupus erythematodes (SLE), evaluation its clinical significance and examination of bacterial colonisation of nostrils and pharynx in SLE patients with a.b . 85 women aged 24-77 (mean 49.3) with mean SLE duration 7.8 (range 1-32) years were examined . All of them fulfilled ARA criteria for the classification of SLE . Among group of patients with a.b . were counted women who had significant bacteriuria > or = 10(4) in ml urine in two cultures . Asymptomatic bacteriuria was found in 14 cases of 85 women with SLE (16.5%) . In two following urine cultures bacteria from family Enterobacteriaceae were dominated: the same types of bacteria were in 85.7%--bacteriuria persistens, in others 14.3% were observed change of bacteria--bacteriuria transistens . In 9 from 14 patients with (64.3%) a.b . very massive growth of Staphylococcus aureus in culture from vestibulae of the nose swab was, in other cultures very massive growth of physiological flora was seen . All patients with a.b . were in clinical remission of SLE and they had no clinical symptoms of infection in urinary tract in 5 months of observation . However clinical significance of asymptomatic bacteriuria and pathogenic bacteria colonisation of nostrils as a precedence to symptomatic infections needs further investigations.

Nahrung, 1999 Apr, 43(2), 126 - 8
Safety and quality of fresh water crayfish Procambarus clarkii in the river Nile; Elmossalami MK et al.; Fresh water crayfish Procambarus clarkii which recently appeared in River Nile and its resources all over Egypt was microbiologically and chemically evaluated in order to determine its safety and quality as human food . The average aerobic plate and Enterobacteriaceae counts/g were 1.6 x 10(8) and 3.5 x 10(5), and the coliforms and E . coli were isolated from 100% and 40% of the examined samples respectively . However, Salmonellae could not be isolated from any of the examined samples . 20% of the samples were safe for human consumption, while 33.33% were marginally acceptable and 46.67% were unacceptable . The mean gross weight, yield of meat, moisture, fat, protein, ash and caloric values were 27.71 g, 12.37%, 82.19%, 0.59%, 15.6%, 1.51% and 283.3 KJ (67.71 Kcal) respectively . Recommended rules for its safety were mentioned.

Genetika, 1999 Jan, 35(1), 5 - 16
{Microcins--peptide antibiotics of enterobacteria: genetic control of the synthesis, structure, and mechanism of action}; Khmel' IA; A general survey of the poorly studied peptide antibiotics, microcins, which are produced by enterobacteria and effect gram-negative bacteria is conducted . In most cases, plasmid genes are responsible for microcin synthesis and the host cell immunity to the produced microcin . A complex system of plasmid and chromosomal genes is involved in the production and immunity to microcins . The chemical structure of three studied microcins is unusual . It was shown that peptides of the microcin molecules are synthesized on ribosomes and often modified posttranslationally . New types of posttranslational modifications were revealed in the biosynthesis of the microcin B17 . These modifications are related to the formation of the thiazole and oxazole rings in its molecule; plasmid genes are responsible for these modifications . It was demonstrated that the smallest gene (21 bp) of all known genes controls the synthesis of the heptapeptide contained in the microcins of the C type.

J Chemother, 1999 Apr, 11(2), 97 - 102
Extended-spectrum beta-lactamase producing strains of Enterobacter cloacae transferring resistance to cefotaxime and ceftazidime; Blahova J et al.; Transferability of ceftazidime resistance and of extended-spectrum beta-lactamase (ESBL) production was recorded in three strains of Enterobacter cloacae from Frankfurt University Clinics . All three strains were resistant to rifampicin, carbenicillin, cephaloridine, cefotaxime, ceftazidime, aztreonam, imipenem and meropenem . They transferred directly determinants of resistance to carbenicillin and cephaloridine to Escherichia coli K-12 No . 185 nal+ recipient strain . All transconjugant colonies also contained determinants of resistance to cefotaxime, ceftazidime and aztreonam . In the second cycle of transfers, determinants of resistance to carbenicillin, cephaloridine, cefotaxime, ceftazidime and aztreonam were transferred en bloc to the recipient Escherichia coli K-12 No . 3110 rif+ indicating that the "transfer factor" (tra+) mediating the process of conjugational transfer had also been co-transferred . Double-disk diffusion test showed the same pattern of production of ESBLs both in original strains and in transconjugants . Transfer of cefotaxime, ceftazidime and aztreonam was accompanied by the transfer of ESBL production.

J Clin Microbiol, 1999 Jun, 37(6), 1758 - 63
Survey of extended-spectrum beta-lactamases in clinical isolates of Escherichia coli and Klebsiella pneumoniae: prevalence of TEM-52 in Korea; Pai H et al.; Two hundred ninety isolates of Escherichia coli were investigated for the production of extended-spectrum beta-lactamases (ESBLs) . Fourteen (4.8%) of the 290 strains were found to produce ESBLs . Each of the 14 strains produced one or two ESBLs, as follows: 10 strains produced TEM-52, 1 strain produced SHV-2a, 1 strain produced SHV-12, 1 strain produced a CMY-1-like enzyme, and 1 strain expressed SHV-2a and a CMY-1-like enzyme . Another two strains for which the MICs of ceftazidime and cefoxitin were high, were probable AmpC enzyme hyperproducers . Because of the high prevalence of TEM-52 in E . coli isolates, we further investigated the TEM-type ESBLs produced by Klebsiella pneumoniae in order to observe the distribution of TEM-52 enzymes among Enterobacteriaceae in Korea . All TEM enzymes produced by 12 strains of K . pneumoniae were identified as TEM-52 . To evaluate the genetic relatedness among the organisms, ribotyping of TEM-52-producing E . coli and K . pneumoniae was performed . The ribotyping profiles of the organisms showed similar but clearly different patterns . In conclusion, TEM-52 is the most prevalent TEM-type ESBL in Korea.

Int J Syst Bacteriol, 1999 Apr, 49 Pt 2, 899 - 905
Erwinia pyrifoliae sp . nov., a novel pathogen that affects Asian pear trees (Pyrus pyrifolia Nakai)
Kim WS, Gardan L, Rhim SL, Geider K.
A novel pathogen from Asian pears (Pyrus pyrifolia Nakai) was analysed by sequencing the 16S rDNA and the adjacent intergenic region, and the data were compared to related Enterobacteriaceae . The 16S rDNA of the Asian pear pathogen was almost identical with the sequence of Erwinia amylovora, in contrast to the 16S-23S rRNA intergenic transcribed spacer region of both species . A dendrogram was deduced from determined sequences of the spacer regions including those of several related species such as Erwinia amylovora, Enterobacter pyrinus, Pantoea stewartii subsp . stewartii and Escherichia coli . Dendrograms derived from 121 biochemical characteristics including Biotype 100 data placed the Asian pear pathogen close to Erwinia amylovora and more distantly to other members of the species Erwinia and to the species Pantoea and Enterobacter . Another DNA relatedness study was performed by DNA hybridizations and estimation of delta Tm values . The Asian pear strains constituted a tight DNA hybridization group (89-100%) and were barely related to strains of Erwinia amylovora (40-50%) with a delta Tm in the range of 5.2-6.8 . The G + C content of DNA from the novel pathogen is 52 mol% . Therefore, it is proposed that strains isolated from Asian pears constitute a new species and the name Erwinia pyrifoliae is suggested; the type strain is strain Ep 16/96T (= CFBP 4172T = DSM 12163T).

Int J Dermatol, 1999 Apr, 38(4), 270 - 4
Bacteriologic and immunologic aspects of gram-negative folliculitis: a study of 46 patients; Neubert U et al.; BACKGROUND: Gram-negative folliculitis is an infection with gram-negative rods that most often occurs as a complication of prolonged broad-spectrum antibiotic therapy in patients suffering from acne and rosacea . METHODS: The bacteriologic and immunologic findings are reported in 46 patients, 39 men and 7 women, aged 16-79 (median, 28) years, with gram-negative folliculitis . Hypersensitivity reactions to various microbial recall antigens as well as granulocyte functions were evaluated . Quantitative measurements of serum levels of immunoglobulin M, G, A, and E, total complement activity, complement factors C3 and C4, and alpha-1-antitrypsin were performed . RESULTS: The gram-negative organisms most frequently cultivated from nares, facial skin, and pustules were Klebsiella spp., Escherichia coli, Enterobacter spp., and Proteus spp . In all patients, deviations of one or more immune parameters were detected, including lowered serum concentrations of immunoglobulin M and alpha-1-antitrypsin, and elevated levels of immunoglobulin E . The humoral and cellular parameters were not influenced by isotretinoin therapy of gram-negative folliculitis . CONCLUSIONS: These findings suggest that gram-negative folliculitis is not only a complication of long-lasting antibiotic treatment of acne and rosacea, but might be an entity of its own . Immunologic factors may play a critical role in the pathogenesis of gram-negative folliculitis.

Mol Microbiol, 1999 May, 32(3), 569 - 80
Substrate-specific binding of hook-associated proteins by FlgN and FliT, putative chaperones for flagellum assembly; Fraser GM et al.; During flagellum assembly by motile enterobacteria, flagellar axial proteins destined for polymerization into the cell surface structure are thought to be exported through the 25-30 A flagellum central channel as partially unfolded monomers . How are premature folding and oligomerization in the cytosol prevented? We have shown previously using hyperflagellated Proteus mirabilis and a motile but non-swarming flgN transposon mutant that the apparently cytosolic 16 . 5 kDa flagellar protein FlgN facilitates efficient flagellum filament assembly . Here, we investigate further whether FlgN, predicted to contain a C-terminal amphipathic helix typical of type III export chaperones, acts as a chaperone for axial proteins . Incubation of soluble radiolabelled FlgN from Salmonella typhimurium with nitrocellulose-immobilized cell lysates of wild-type S . typhimurium and a non-flagellate class 1 flhDC mutant indicated that FlgN binds to flagellar proteins . Identical affinity blot analysis of culture supernatants from the wild-type and flhDC, flgI, flgK, flgL, fliC or fliD flagellar mutants showed that FlgN binds to the flagellar hook-associated proteins (HAPs) FlgK and FlgL . This was confirmed by blotting artificially expressed individual HAPs in Escherichia coli . Analysis of axial proteins secreted into the culture medium by the original P . mirabilis flgN mutant demonstrated that export of FlgK and FlgL was specifically reduced, with concomitant increased release of unpolymerized flagellin (FliC), the immediately distal component of the flagellum . These data suggest that FlgN functions as an export chaperone for FlgK and FlgL . Parallel experiments showed that FliT, a similarly small (14 kDa), potentially helical flagellar protein, binds specifically to the flagellar filament cap protein, FliD (HAP2), indicating that it too might be an export chaperone . Flagellar axial proteins all contain amphipathic helices at their termini . Removal of the HAP C-terminal helical domains abolished binding by FlgN and FliT in each case, and polypeptides comprising each of the HAP C-termini were specifically bound by FlgN and FliT . We suggest that FlgN and FliT are substrate-specific flagellar chaperones that prevent oligomerization of the HAPs by binding to their helical domains before export.

Mayo Clin Proc, 1999 May, 74(5), 519 - 28
The aminoglycosides; Edson RS et al.; Despite the introduction of newer, less toxic antimicrobial agents, the aminoglycosides continue to serve a useful role in the treatment of serious enterococcal, mycobacterial, and gram-negative bacillary infections . Gentamicin, because of its low cost, remains the aminoglycoside of choice in hospitals with low levels of resistance among Enterobacteriaceae and Pseudomonas aeruginosa . Typically, it is administered in combination with beta-lactam antibiotics, but it may also be used as monotherapy for urinary tract infections or tularemia . Amikacin is useful against gentamicin-resistant gram-negative bacilli and also in the treatment of infections caused by susceptible Nocardia and nontuberculous mycobacteria . Streptomycin serves an important role in the treatment of multidrug-resistant tuberculosis and may be useful in the treatment of some gentamicin-resistant enterococcal infections . Despite an alarming increase in aminoglycoside-resistant enterococci, most institutions have noted little change in patterns of resistance among gram-negative bacilli . Although the development of newer, less toxic aminoglycosides is unlikely in the near future, single daily dosing regimens have been proposed as a convenient, cost-effective strategy . In selected patients, this novel approach seems to be as safe and effective as traditional, multidose regimens.

Scand J Gastroenterol, 1999 Mar, 34(3), 264 - 9
Protective effect of lactosucrose on intracolonic indomethacin-induced small-intestinal ulcers in rats; Honda K et al.; BACKGROUND: Little is known about the role of intestinal microflora in the development of indomethacin-induced enteropathy . The aim of this study was to evaluate the effects of lactosucrose, an indigestible oligosaccharide, on intestinal microflora and on indomethacin-induced enteropathy in rats . METHODS: Male Wistar rats were fed either sucrose (SC) or lactosucrose (LS) for 2 weeks . Indomethacin (24 mg/kg/ day) was administered into the colon twice, 24 h apart, and intestinal ulcers in SC and LS groups were compared macroscopically . In another experiment the bacterial composition in the mid-small-intestinal segment was determined in both groups before and after treatment with indomethacin . RESULTS: After indomethacin treatment small-intestinal ulcers were less severe in the LS than in the SC group (ulcer index: median, 0.13 (range, 0.05-0.19) versus 0.23 (0.13-0.34); P < 0.05) . Total bacterial count did not differ significantly between the two groups . Indomethacin increased the number of Enterobacteriaceae in both groups, but the increase was less in the LS group . The number of streptococci was also significantly increased in the SC group but not in the LS group . CONCLUSION: These results suggest that LS has some protective effects on indomethacin-induced enteropathy and that this protective effect is in part due to the maintenance of intestinal microflora.

Transplantation, 1999 Apr 27, 67(8), 1138 - 44
Pulmonary infiltrates in liver transplant recipients in the intensive care unit; Singh N et al.; BACKGROUND: A frequent dilemma is discerning the likelihood of pneumonia and the need for empiric antibiotic therapy in liver transplant recipients with pulmonary infiltrates in the intensive care unit (ICU) . METHODS: We performed a prospective, observational study of consecutive liver transplant recipients developing pulmonary infiltrates in the ICU . RESULTS: Of 90 consecutive liver transplant patients in the ICU over a 3-year period, 44% (40) developed pulmonary infiltrates . The etiologies were pneumonia (38%, 15 of 40), pulmonary edema (40%, 16 of 40), atelectasis (10%, 4 of 40), adult respiratory distress syndrome (8%, 3 of 40), contusion (3%, 1 of 40), and unknown (3%, 1 of 40) . Pneumonia was due to methicillin-resistant Staphylococcus aureus in 27% (4 of 15), Pseudomonas aeruginosa (27%, 4 of 15), invasive aspergillosis (20%, 3 of 15), and Enterobacter cloacae, Serratia marcescens, Pneumocystis carinii pneumonia, and unknown (7%, 1 of 15) in one each . None of the patients had cytomegalovirus or herpes simplex virus pneumonia . Seventy-five percent of methicillin-resistant Staphylococcus aureus and all Aspergillus pneumonias, but only 14% of the Gram-negative pneumonias, occurred within 30 days of transplantation . Twenty-seven percent of the pneumonias occurred >365 days after transplantation; all of these were in patients with recurrent viral hepatitis C virus or hepatitis B virus, disseminated posttransplant lymphoproliferative disorder, or late rejection . Of patients with pneumonia, 87% were ventilated and 40% had bacteremia . Clinical pulmonary infection score (Pugin score) >6 (73% vs . 6%, P = 0.0001), abnormal temperature (73% versus 28%, P = 0.005), and creatinine level >1.5 mg/dl (80% versus 50%, P = 0.05) were predictors of pneumonia versus other etiologies of pulmonary infiltrates . Overall mortality in patients with pulmonary infiltrates was 28% (11 of 40); pneumonia as etiology (P = 0.06), creatinine level >1.5 mg/dl (P = 0.028), higher blood urea nitrogen (P = 0.017), and worse APACHE neurological score (P = 0.04) were predictors of poor outcome . CONCLUSIONS: Our data have implications not only for identifying pneumonia as a potential cause of pulmonary infiltrates, but for the likely etiology of the pneumonia and thus the selection of empiric antibiotic therapy in critically ill liver transplant recipients . Pugin score >6 in patients with pulmonary infiltrates warrants antimicrobial therapy . Early onset within 30 days after transplantation raises the spectra of aspergillosis.

Rev Esp Enferm Dig, 1999 Feb, 91(2), 105 - 16
Bacteremia caused by digestive system endoscopy; Barragan Casas JM et al.; AIM: to evaluate bacteremias caused during endoscopic examination of the digestive tract . PATIENTS AND METHODS: prospective study of randomly selected patients who underwent digestive system endoscopic examination . Emergency endoscopic examinations were excluded . RESULTS: a total of 102 patients were analyzed . Of 44 patients who underwent gastroscopy, 11 (25%) subsequently had positive blood culture, and Staphylococcus spp and Streptococcus spp were isolated . Of 30 patients who underwent colonoscopy, 3 (10%) had positive blood cultures, and Staphylococcus spp were isolated . Of 28 patients who underwent endoscopic retrograde cholangiopancreatography, 11 (39.2%) had positive blood cultures, and Escherichia coli, Morganella morganii, Staphylococcus spp and Streptococcus spp were isolated . No deaths, endocarditis or other septic phenomena were attributed to bacteremia . CONCLUSIONS: the incidence of bacteremia ranged from 10% to 39% depending on the type of endoscopy . The microorganisms that were isolated most frequently were Staphylococcus spp and Streptococcus spp . Gram-negative bacilli and enterobacteria were isolated in patients who had undergone endoscopic retrograde cholangiopancreatography.

APMIS, 1999 Apr, 107(4), 437 - 44
Direct antimicrobial susceptibility testing in bacteriuria; Bronnestam R; A method for diagnosis of bacteriuria using semiquantitative culture in combination with direct susceptibility testing is described . Susceptibility testing with the breakpoint method was performed by means of a multiple inoculation technique . A simple biochemical typing on solid media of lactose-fermenting Enterobacteriaceae strains and aesculin testing of Enterococcus strains were performed simultaneously . Staphylococcus and Streptococcus strains were tested for susceptibility using the conventional disc diffusion technique . The results of the direct susceptibility test and the disc diffusion test were compared in a study of 983 consecutively positive urine cultures: 6624 susceptibility tests from 882 specimens with one microorganism revealed complete agreement in 6343 cases (95.8%); the discrepant results were 15 very major errors (0.2%), 84 major errors (1.3%) and 182 minor errors (2.7%) . The direct susceptibility test revealed 42 more cases of bacteriuria with enterococci in combination with Enterobacteriaceae strains compared to the conventional method . 59% of all positive urine cultures were completed, including the susceptibility test report, within 24 h after arriving at the laboratory . The diagnostic costs were approximately the same as for the conventional method.

J Med Microbiol, 1999 May, 48(5), 433 - 41
Cross-reactivity between six Enterobacteriaceae complete lipopolysaccharide core chemotypes; Nnalue NA et al.; To gain insight into the value of lipopolysaccharide (LPS) core determinants for cross-protective immunisation the serological relationships between six complete (LPS) core types from Enterobacteriaceae were investigated . Hyperimmune sera were raised in mice by repeated immunisation with heat-killed strains of Salmonella choleraesuis (Ra core type) or Escherichia coli (core types R1, R2, R3, R4 and K12) and characterised for reactivity with complete and incomplete core chemotypes by ELISA and immunoblotting . Three sera (anti-Ra, anti-R2 and anti-R3) reacted strongly with 3-5 different complete core types whereas the other three (anti-R1, anti-R4 and anti-K12) reacted strongly only with their homologous core types in these assays . Two approaches were used to examine further the structural bases for cross-reactivity between these cores . By the first approach the anti-complete-core sera were tested for cross-reactivity with truncated forms of the Salmonella species core (incomplete cores) derived from core-defective mutants . By the second approach, antisera raised against some core-defective mutants were tested for cross-reactivity with complete cores . The results of these investigations revealed that several pair-wise combinations of core types can be used as immunogens to elicit immune responses that recognise all six core types and that the major determinants which mediate cross-reactivity between complete cores are localised in the outer core region.

J Antimicrob Chemother, 1999 Mar, 43 Suppl A, 3 - 23
In-vitro susceptibility of 1982 respiratory tract pathogens and 1921 urinary tract pathogens against 19 antimicrobial agents: a Canadian multicentre study . Canadian Antimicrobial Study Group; Blondeau JM et al.; A total of 3903 pathogens from 48 Canadian medical centres were tested against 19 antimicrobial agents . Five agents showed activity against > or = 90% of all 1982 respiratory tract pathogens tested (ciprofloxacin, 90%; cefoperazone, 91%; ticarcillin/clavulanate, 92%; ceftazidime and imipenem, 93% each) . Nine agents had > or = 90% activity against Enterobacteriaceae from respiratory tract infection (cefotaxime and ticarcillin/clavulanate, 90% each; aztreonam, ceftizoxime and ceftriaxone, 91% each; ceftazidime, 93%; ciprofloxacin, 97%; imipenem and netilmicin, 98% each) . Similarly, five agents had activity against > or = 90% of all 1921 urinary tract pathogens tested (ciprofloxacin and ticarcillin/clavulanate, 90% each; cefoperazone and netilmicin, 91% each; imipenem, 99%) . Nine agents had > or = 95% activity against Enterobacteriaceae from urinary tract infection (ciprofloxacin, 95%; cefotetan, 97%; aztreonam, cefotaxime, ceftazidime, ceftizoxime, ceftriaxone and netilmicin, 98% each; imipenem, 99%) . Seventeen agents had activity against > or = 95% of Staphylococcus aureus strains . Susceptibility of Pseudomonas aeruginosa isolates ranged from 2% to 91%.

Antimicrob Agents Chemother, 1999 May, 43(5), 1281 - 4
An SHV-derived extended-spectrum beta-lactamase in Pseudomonas aeruginosa; Naas T et al.; A clinical isolate of Pseudomonas aeruginosa RP-1 produced the extended-spectrum beta-lactamase (ESBL) SHV-2a . Its gene was expressed from a composite promoter made of the -35 region derived from the left inverted repeat of IS26 and the -10 region from the blaSHV-2a promoter itself . The DNA sequences immediately surrounding blaSHV-2a were homologous to plasmid pMPA2a from Klebsiella pneumoniae KpZU-3, while further away and 3' to the blaSHV-2a gene, a sequence corresponding to the left end of Tn1721 was detected, thus indicating a likely enterobacterial origin of this ESBL gene.

Wiad Lek, 1998, 51(11-12), 504 - 12
{Bacterial infections in cancer patients: what should we treat them with when the result of antibiogram is not yet known?}; Pysz M; Cancer patients are prone to bacterial infections, which frequently on account of severity require prompt administration of antibiotics--even before the result of antibiogram is known . 500 antibiograms obtained from cultures taken from 307 cancer patients treated in General Hospital no . 2, Bielsko-Biala during 1991-1995 were analyzed . Marked diversity in isolated bacterial strains was found, the dominant pathogens being Gram positive species (mainly Staphylococci and Streptococci, which constituted 46.2% of all isolated strains) . The most frequent Gram negative species were Escherichia coli, Proteus spp., Klebsiella spp . and Enterobacter spp . Analysis of antibiotic efficiency suggests that cancer patients in case of infection should be treated empirically as follows: 1 . Moderate infection--monotherapy with broad spectrum antibiotic, covering also Gram positive bacteria--such as ciprofloxacin . 2 . Severe infection--combination therapy consisting of two antibiotics: one with activity against Gram positive bacteria such as cloxacillin, erythromycin, cefazolin, cephalexin, clindamycin--the other with activity against Gram negative bacteria, such as aminoglycoside (e.g., netilmicin, amikacin) or third generation cephalosporine (e.g., cefotaxime, ceftriaxone).

Med Dosw Mikrobiol, 1998, 50(3-4), 215 - 22
{Estimation of mean molecular weight of Enterobacteriaceae lipopolysaccharides using gas chromatography for determination of fatty acids}; Ziolkowski A et al.; In the paper, we propose a method for estimation of the mean molecular weight of lipopolysaccharide, which is important for accuracy of endotoxin activity investigation . In our study, it was assumed that lipid A portion in Enterobacterial lipopolysaccharide is substituted by four 3-hydroxytetradecanoic acid residues . Lipopolysaccharides of S, Ra, Rc and Re chemotypes being laboratory preparations as well as purchased from Sigma were investigated . Fatty acids were determined by of gas chromatography as methyl esters according to the procedure described by Wollenweber and Rietschel . Mean molecular weight was calculated by the formula: MMW = {formula: see text} . A high agreement between the estimated and the theoretical molecular weight values was demonstrated in the case of Salmonella minnesota R595 (Re) LPS preparation . As expected, LPS heterogeneity increase together with enlargement of polysaccharide chain length which is visible in electrophoregrams also . Except for LPS mean molecular weight estimation, the method allows its detection in various preparations and samples, distinguishing of R and S LPS forms as well as the determination of mean length of O-specific chain in lipopolysaccharides which structures are known.

Pediatr Int, 1999 Apr, 41(2), 157 - 61
Enterobacter aerogenes outbreak in a neonatal intensive care unit; Loiwal V et al.; BACKGROUND: Enterobacter aerogenes, a Gram-negative bacterium, is an important, although infrequent, cause of nosocomial bacteremia in the hospitalized pediatric and neonatal population . Enterobacter aerogenes was isolated for the first time in our neonatal intensive care unit (NICU) from blood culture of a 5-day-old neonate; 12 more cases were discovered in the next 70 days . The present report summarizes the clinico-bacteriological spectrum and outcome of the affected neonates . Efforts made to find the source of infection and curb the outbreak are also presented . METHODS AND RESULTS: Thirteen newborns, including seven preterms, acquired E . aerogenes septicemia . Perinatal risk factors were present in all the neonates . The mean birthweight of affected infants was 1880 +/- 540 g . Symptoms appeared at a mean age of 3.5 +/- 1.5 days (range 3-8 days) . The clinical presentation was indistinguishable from septicemia caused by other Gram-negative organisms . Complications encountered included sclerema, bleeding diathesis, meningitis and shock . The organism, isolated from blood in all and from the cerebrospinal fluid in two cases, was found to be resistant to all antibiotics in the first five cases, but turned sensitive to gentamicin, cefotaxime and amikacin during the latter half of the epidemic . The bacterium in the last case (no . 13) was again found to be resistant to all the antibiotics . Overall mortality was 46.2%; the mean interval between onset of symptoms and death being 2.3 +/- 1.8 days . The organism was traced to the rubber pipe attached to a foot-operated suction machine in the NICU . The neonatal unit was temporarily closed, fumigated and reopened with strict instructions to follow proper hand washing protocol and ensure cohort nursing of infected infants . CONCLUSIONS: Enterobacter aerogenes is capable of causing nosocomial outbreaks of septicemia in NICU . Low birthweight infants with associated perinatal risk factors appear to be predisposed . The sensitivity patterns of the isolates highlight the capability of E . aerogenes to acquire or lose resistance to antibiotics rapidly during treatment . A high mortality rate coupled with a short interval between onset of symptoms and death, suggested high virulence of the strain.

Monaldi Arch Chest Dis, 1999 Feb, 54(1), 11 - 7
Community-acquired pneumonia in adults: a multicentric observational AIPO study; Logroscino CD et al.; The aim of this study was to obtain reliable data about the current aetiology (i.e . the frequency of the individual pathogens) of community-acquired pneumonia (CAP) while surveying the diagnostic and therapeutic behaviour of Italian chest physicians, compared with existing guidelines, and to test the usefulness of the current severity "criteria" or score as a predictor of disease outcome and guide for appropriate hospitalization . A prospective multicentre observational trial was carried out between October 1994 and February 1996 by the Italian Association of Hospital Pneumologists (AIPO) study group on respiratory infections . A total of 613 consecutive patients suffering from CAP were enrolled in 25 centres throughout Italy . Clinical, radiological and microbiological data were collected and patients were followed-up until complete resolution or death . Aetiological tests were not carried out in 204 patients . In the remaining 409 cases, the aetiology was defined by serological and quantitative microbiological tests in 184 (44.9%) patients . A total of 194 strains of pathogen were detected . The most frequently detected micro-organism was Streptococcus pneumoniae (18.5% of pathogen strains) but, unlike in other series of patients, high percentages of intracellular pathogens (32.5%, all with serological confirmation, mostly due to Chlamydia pneumoniae (13.4%) and of Gram-negative enterobacteria and Pseudomonas aeruginosa (12.5%) were also found . Antibiotic treatment differed from that recommended in American Thoracic Society guidelines, with a greater use of third-generation cephalosporins . Overall, a higher rate of hospitalization and a lower death rate than in other comparable studies was observed.

Am J Vet Res, 1999 Apr, 60(4), 501 - 6
Seroprevalence of antibodies against gram-negative core antigens in rabbits, using an Escherichia coli J5 antigen-capture enzyme-linked immunosorbent assay; Ruble RP et al.; OBJECTIVE: To determine the seroprevalence of antibodies to gram-negative core antigens (GNCA) in specific-pathogen-free (SPF) rabbits (ie, free of Pasteurella multocida) and rabbits of undefined bacterial status (conventional) . SAMPLE POPULATION: Serum samples were obtained from 7 groups of rabbits . The SPF rabbits comprised 2 adult groups and 1 immature group, whereas the 4 groups of conventional rabbits were all adults . PROCEDURE: A seroprevalence survey was conducted on rabbit sera for antibodies against GNCA, using an Escherichia coli J5 antigen-capture ELISA . RESULTS: Collective geometric mean titer (GMT) of adult rabbits was 1:6,463 . The GMT of each of the 6 groups of adult rabbits was 1:956, 1:1,133, 1:4,525, 1:5,338, 1:7,669, and 1:25,600 . Titers of populations differed significantly . CONCLUSION: Data analysis revealed there were anti-GNCA antibodies in rabbits . Similar to other species, the prevalence of IgM and IgG anti-GNCA antibodies increased with age . The IgG response was more marked than the IgM response . The SPF rabbits had lower IgG anti-GNCA titers than conventional rabbits, indicating possible cross-reactive epitopes between P multocida and Enterobacteriaceae . Rabbits with the highest anti-GNCA titers were those used in polyclonal antibody production, possibly stemming from endotoxin contamination of antigen or adjuvant . CLINICAL RELEVANCE: The possible cross-reactive antibodies directed at homologous wall components of Pasteurellaceae and Enterobacteriaceae could prove to be a possible heterotypic vaccination strategy for the protection of rabbits against pasteurellosis . Investigators should determine whether antigen impurity (endotoxin contamination) influences epitope focus during polyclonal antibody production and whether it affects sera variability among rabbits.

Microbiology, 1999 Jan, 145 ( Pt 1), 115 - 25
Structure and function of a cysBJIH gene cluster in the purple sulphur bacterium Thiocapsa roseopersicina; Haverkamp T et al.; A gene cluster containing homologues of the genes cysB, cysJI and cysH was found in the genome of the sulphur-oxidizing purple bacterium Thiocapsa roseopersicina . The nucleotide sequence indicated four open reading frames encoding homologues of 3'-phosphoadenylylsulphate (PAPS) reductase (CysH), sulphite reductase flavoprotein (CysJ) and haem protein (CysI) subunits, and a transcriptional regulator (CysB) . Genes cysJIH are separated by a short cis-active intergenic region from cysB which is transcribed divergently . cysB encodes a polypeptide of 35.9 kDa consisting of 323 amino acid residues with 40% identity to the CysB regulator from enterobacteria . cysH encodes a protein with 239 amino acid residues and a calculated mass of 27.7 kDa; cysJ encodes a protein with 522 amino acid residues and a mass of 57.8 kDa; and cysI encodes a protein with 559 amino acid residues and a mass of 62.3 kDa . The cysJIH gene products have been expressed and used for complementation of cys mutants from Escherichia coli Biochemical analysis . The gene product CysH is a thioredoxin-dependent PAPS reductase (EC 1.8.99.4) . It was repressed under photoautotrophic growth using hydrogen sulphide as electron donor and derepressed under conditions of sulphate deficiency . Products of the cysJI genes were identified as the two subunits of NADPH-sulphite reductase (EC 1.8.1.2) . cysJ encoded the flavoprotein, with > or = 39% identity to the protein from E . coli, and cysI encoded the haem protein, with > or = 53% identity . A cysI clone was used to complement the corresponding mutant from E . coli and to express enzymically active methylviologen-sulphite reductase.

Mol Microbiol, 1999 Mar, 31(5), 1417 - 28
Identification of UreR binding sites in the Enterobacteriaceae plasmid-encoded and Proteus mirabilis urease gene operons; Thomas VJ et al.; The closely related Proteus mirabilis and Enterobacterlaceae plasmid-encoded urease genes are positively regulated by the AraC-like transcriptional activator UreR . In the presence of the effector molecule urea, UreR promotes transcription of ureD, the initial gene in the urease operon, and increases transcription of the divergently transcribed ureR . Here, we identify UreR-specific binding sites in the ureRp-ureDp intergenic regions . Recombinant UreR (rUreR) was expressed and purified, and gel shift and DNase I protection assays were performed with this protein . These analyses indicated that there are two distinct rUreR binding sites in both the plasmid-encoded and P . mirabilis ureRp-ureDp intergenic regions . A consensus binding site of TA/GT/CA/TT/GC/TTA/TT/AATTG was predicted from the DNase I protection assays . Although rUreR bound to the specific DNA binding site in both the presence and the absence of urea, the dissociation rate constant k-1 of the rUreR-DNA complex interaction was measurably different when urea was present . In the absence of urea, the dissociation of the protein-DNA complexes, for both ureRp and ureDp, was complete at the earliest time point, and it was not possible to determine a rate . In the presence of urea, dissociation was measurable with a k-1 for the rUreR-ureRp interaction of 1.2 +/- 0.2 x 10(-2) s-1 and a k-1 for the rUreR-ureDp interaction of 2.6 +/- 0.1 x 10(-3) s-1 . This corresponds to a half-life of the ureRp-rUreR interaction of 58 s, and a half-life of the ureDp-rUreR interaction of 4 min 26 s . A model describing a potential role for urea in the activation of these promoters is proposed.

J Appl Microbiol, 1999 Jan, 86(1), 29 - 35
New types of antimicrobial compounds produced by Lactobacillus plantarum; Niku-Paavola ML et al.; New types of antimicrobial compounds were identified in the culture filtrate of Lactobacillus plantarum VTT E-78076 . Activity was detected in the low molecular mass fraction separated by gel chromatography . This fraction totally inhibited the growth of the Gram-negative test organism, Pantoea agglomerans (Enterobacter agglomerans) VTT E-90396 . Characteristic compounds from this fraction were identified by GC/MS-analysis and the identification was confirmed using pure commercial reference compounds in identical chromatographs and in antimicrobial tests . The active fraction included benzoic acid (CAS 65-85-0), 5-methyl-2,4-imidazolidinedione (CAS 616-03-5, methylhydantoin), tetrahydro-4-hydroxy-4-methyl-2H- pyran-2-one (CAS 674-26-0, mevalonolactone) and 3-(2-methylpropyl)-2,5-piperazinedione (CAS 5845-67-0, cyclo(glycyl-L-leucyl)) . These compounds in concentrations of 10 ppm inhibited growth of the test organism by 10-15% when acting separately, but 100% when all were applied together with 1% lactic acid . The inhibition was 40% by 1% lactic acid alone . The compounds were also active against Fusarium avenaceum (Gibberella avenacea) VTT-D-80147 . The inhibition was 10-15% by separate compounds in concentrations of 10 ppm and maximally 20% in combinations . Fungal growth was not inhibited by lactic acid . Inhibition by unfractionated Lact . plantarum culture filtrate was 37% and by the low molecular mass fraction, 27%.

J Appl Microbiol, 1999 Mar, 86(3), 429 - 38
Effect of elevated oxygen and carbon dioxide on the surface growth of vegetable-associated micro-organisms; Amanatidou A et al.; The impact of a novel type of Modified Atmosphere (MA), referred to as high O2-MA, on micro-organisms associated with the spoilage of minimally-processed vegetables was studied . Pure cultures of Pseudomonas fluorescens, Enterobacter agglomerans, Aureobacterium strain 27, Candida guilliermondii, C . sake, Salmonella typhimurium, Salm . enteritidis, Escherichia coli, Listeria monocytogenes, Leuconostoc mesenteroides var . mesenteroides, Lactobacillus plantarum and Lactococcus lactis were cultured on an agar-surface model system and incubated at 8 degrees C under an atmosphere composed of O2 (80 or 90%, balanced with N2), CO2 (10 or 20%, balanced with N2), or a combination of both gases . In general, exposure to high O2 alone did not inhibit microbial growth strongly, while CO2 alone reduced growth to some extent in most cases . Consistently strong inhibition was observed only when the two gases were used in combination . With minimally-processed vegetables, where CO2 levels of around 20% or above cannot be used because of physiological damage to the produce, the combined treatment of high O2 and 10-20% CO2 may provide adequate suppression of microbial growth, allowing a safe, prolonged shelf-life.

Drugs, 1999 Mar, 57(3), 363 - 73; discussion 374
Moxifloxacin; Balfour JA et al.; Moxilloxacin is a new fluoroquinolone antibacterial agent with a broad spectrum of activity, encompassing gram-negative and gram-positive bacteria . It has improved activity against gram-positive species (including staphylococci, streptococci, enterococci) and anaerobes compared with ciprofloxacin . This is offset by slightly lower activity against pseudomonal species and Enterobacteriaceae . In common with other fluoroquinolones, moxifloxacin attains good penetration into respiratory tissues and fluids and its bioavailability is substantially reduced by coadministration with an antacid or iron preparation . However, moxifloxacin does not interact with theophylline or warfarin . In clinical trials in patients with community-acquired pneumococcal pneumonia (CAP), acute exacerbations of chronic bronchitis (AECB) or acute sinusitis, moxifloxacin 400 mg once daily achieved bacteriological and/or clinical success rates of approximately 90% or higher . Moxifloxacin was as effective as amoxicillin 1 g 3 times daily and clarithromycin 500 mg twice daily in CAP and as effective as clarithromycin in AECB . In patients with sinusitis, a 7-day course of moxifloxacin 400mg once daily was as effective as a 10-day course of cefuroxime axetil 250mg twice daily . In contrast to some other fluoroquinolones, moxifloxacin appears to have a low propensity for causing phototoxic and CNS excitatory effects . The most common adverse events are gastrointestinal disturbances.

Biotechnol Bioeng, 1998 Apr 5, 58(2-3), 303 - 5
Uncoupled glycerol distribution as the origin of the accumulation of 3-hydroxypropionaldehyde during the fermentation of glycerol by enterobacter agglomerans CNCM 1210
Barbirato F, Soucaille P, Camarasa C, Bories A.
Batch fermentation of glycerol to 1,3-propanediol (1,3PPD) by Enterobacter agglomerans CNCM 1210 showed the lethal accumulation of 3-hydroxypropionaldehyde (3-HPA) when performed under initial substrate content higher than 40 g/L . Assigned to the inhibition by the NAD/NADH ratio of the 3-HPA converting enzyme: 1,3PPD dehydrogenase, intracellular assays were conducted in an attempt to identify the metabolic mechanisms involved in the increase of that ratio . An overflow metabolism through the 1,3PPD formation pathway was established, while a catabolic limitation in the oxidative branch at the level of glyceraldehyde-3-phosphate dehydrogenase occurred . Uncoupled activities of synthesis and consumption of reducing equivalents are thus suspected to provoke the increase of the NAD/NADH ratio and the subsequent accumulation of 3-HPA .

Cent Afr J Med, 1998 Nov, 44(11), 283 - 6
Significance of polymicrobic bacteriuria in a teaching hospital in Trinidad; Orrett FA; OBJECTIVE: To compare microbial prevalence (mixed versus pure), define microbial combination in mixed urine cultures among inpatients and outpatients and to identify factors that might allow a more objective interpretation of polymicrobic urine cultures . DESIGN: Case series . SETTING: The study involved inpatients (hospitalized) and outpatients (those attending outpatient clinics and the accident and emergency department) of the San Fernando General Hospital in southern Trinidad . MAIN OUTCOME MEASURES: Prevalence rates of bacterial isolates in mixed and pure cultures of urine specimens were determined using standard techniques and Kirby-Bauer disc diffusion methodology . RESULTS: The results obtained showed that of 5,089 urine specimens, 1,491 (29.3%) yielded positive cultures . Of these positive cultures, 524 (35.1%) revealed significant polymicrobic bacteriuria . Eighty five percent yielded two organisms, 13.2% had three organisms and 1.8% had four organisms . Repeat cultures in 157 patients revealed the same organisms in only 57.3% of them . Almost all of the repeat cultures were from patients with in-dwelling Foley catheters . E . coli was the most common single isolate (42.8%), while Klebsiella, Enterobacter and Proteus organisms were most often encountered in mixed cultures . All isolates were relatively sensitive to routinely used antibiotics for urinary pathogens . CONCLUSION: The prevalence rate of polymicrobic bacteriuria at our institution was 10.2% . More than 65% of positive cultures were from patients with Foley catheters on open drainage (inpatients) and closed drainage (outpatients) . Most were men with out-flow obstruction who either refused surgery, were unfit for surgery, or had to wait long periods to be booked for surgery . No cases developed bacteremia secondary to bacteriuria . All urinary isolates were susceptible to routinely used antimicrobial agents.

Pediatrics . 1999 Apr;103(4):e39.
Nosocomial infections in pediatric intensive care units in the United States . National Nosocomial Infections Surveillance System; Richards MJ et al.; OBJECTIVES: To describe the epidemiology of nosocomial infections in pediatric intensive care units (ICUs) in the United States . BACKGROUND: Patient and ICU characteristics in pediatric ICUs suggest the pattern of nosocomial infections experienced may differ from that seen in adult ICUs . METHODS: Data were collected between January 1992 and December 1997 from 61 pediatric ICUs in the United States using the standard surveillance protocols and nosocomial infection site definitions of the National Nosocomial Infections Surveillance System's ICU surveillance component . RESULTS: Data on 110 709 patients with 6290 nosocomial infections were analyzed . Primary bloodstream infections (28%), pneumonia (21%), and urinary tract infections (15%) were most frequent and were almost always associated with use of an invasive device . Primary bloodstream infections and surgical site infections were reported more frequently in infants aged 2 months or less as compared with older children . Urinary tract infections were reported more frequently in children >5 years old compared with younger children . Coagulase-negative staphylococci (38%) were the most common bloodstream isolates, and aerobic Gram-negative bacilli were reported in 25% of primary bloodstream infections . Pseudomonas aeruginosa (22%) was the most common species reported from pneumonia and Escherichia coli (19%), from urinary tract infections . Enterobacter spp . were isolated with increasing frequency from pneumonia and were the most common Gram-negative isolates from bloodstream infections . Device-associated infection rates for bloodstream infections, pneumonia, and urinary tract infections did not correlate with length of stay, the number of hospital beds, or season . CONCLUSIONS: In pediatric ICUs, bloodstream infections were the most common nosocomial infection . The distribution of infection sites and pathogens differed with age and from that reported from adult ICUs . Device-associated infection rates were the best rates currently available for comparisons between units, because they were not associated with length of stay, the number of beds in the hospital, or season.

Appl Environ Microbiol, 1999 Apr, 65(4), 1781 - 5
Different strategies for molecular differentiation of Mycobacterium bovis strains isolated in Sardinia, Italy; Sechi LA et al.; Different genetic markers were used to analyze 22 Mycobacterium bovis strains isolated from cattle in Sardinia and one human isolate . IS6110 DNA fingerprinting differentiated the strains into six patterns, whereas with enterobacterial repetitive consensus sequence primers produced seven clusters . PCR ribotyping followed by digestion with HaeIII and PvuII produced five and seven patterns, respectively . PCR with the (GTG)5 oligonucleotide primer showed the best discriminatory power, generating eight clusters among the strains analyzed.

Hum Reprod Update, 1998 Nov-Dec, 4(6), 891 - 903
Seminal tract infections: impact on male fertility and treatment options; Keck C et al.; Bacterial and viral infections of the genital tract may be important aetiological factors for male infertility . Infectious processes may lead to deterioration of spermatogenesis, impairment of sperm function and/or obstruction of the seminal tract . Detection of bacteria in semen does not necessarily signify infection since bacteriospermia may represent contamination, colonization or infection . Reported prevalence of Ureaplasma urealyticum in human semen varies from 10 to 40% . Enterobacteria can even be found in up to 90% of semen samples depending on the sensitivity of detection methods used . Chlamydia trachomatis is the most frequent sexually transmitted bacterial organism in industrialized countries . It is suggested that its main influence is due to sexual transmission resulting in tubal disease and subsequent infertility in the female partner rather than a direct influence on male reproductive functions . The effect of leukocytospermia on male fertility is controversial . This is probably due to different detection methods, different populations studied and to the fact that leukocyte subtypes in semen may have different functions . In addition to potentially negative effects, leukocytes may even have protective effects on spermatozoa . Only recently have amplification methods been established to detect viruses in semen with high sensitivity and specificity . It is unclear if these infections significantly contribute to male infertility.

Yonsei Med J, 1998 Dec, 39(6), 514 - 9
The characteristics of extended-spectrum beta-lactamases in Korean isolates of Enterobacteriaceae; Pai H; Extended-spectrum beta-lactamases (ESBLs) in gram-negative organisms have been implicated as the enzymes responsible for resistance to oxyimino-cephalosporins . The incidence of ESBL-producers in Korean isolates of Escherichia coli and Klebsiella pneumoniae were in the range of 4.8-7.5% and 22.5-22.8%, respectively . The ESBL-producing isolates revealed variable levels of resistance to cefotaxime, ceftazidime and aztreonam . They also showed the elevated MIC values of non-beta-lactam antibiotics . SHV-12 and SHV-2a were the enzymes most frequently found in K . pneumoniae strains, but TEM-52 was the most prevalent in E . coli isolates . About 15% of ESBL-producing isolates of Enterobacteriaceae produced CMY-1 enzyme, which conferred resistance to cephamycins such as cefoxitin as well as oxyimino-cephalosporins . Thus, the most common types of ESBLs in Korea are TEM-52, SHV-12 SHV-2a, and CMY-1.

J Commun Dis, 1998 Sep, 30(3), 147 - 52
Neonatal sepsis in hospital born babies; Kaushik SL et al.; Incidence of neonatal sepsis in a study carried out among hospital born babies was found to be 5.3 per cent significantly high (10.9%) amongst low birth weight compared to (3.1%) normal birth weight babies . Sepsis related mortality also exceeded significantly in low birth weight babies . Positive cultures were obtained in 36.7 per cent of babies with sepsis . The organisms identified were Staphylococcus pyogenes (40%), E . coli (27.5%), Klebsiella spp . (15%), Staphylococcus epidermidis (10%) and Enterobacter spp . (7.5%) . Gram negative bacilli predominated in early onset (< 72 hrs . of life) and gram positive cocci in late onset . Mortality with early onset culture positive neonatal sepsis was significantly high compared to late onset . The bacterial isolates obtained were found to be resistant to routinely used antibiotics (penicillin, ampicillin and gentamycin) . Third generation cephalosporins and aminoglycosides (netilmycin) were found to be effective in treatment of neonatal sepsis.

Eur J Biochem, 1999 Feb, 259(3), 747 - 55
The cyclic structure of microcin J25, a 21-residue peptide antibiotic from Escherichia coli; Blond A et al.; Microcin J25 (MccJ25) is the single representative of the immunity group J of the microcin group of peptide antibiotics produced by Enterobacteriaceae . It induces bacterial filamentation in susceptible cells in a non-SOS-dependent pathway {R . A . Salomon and R . Farias (1992) J . Bacteriol . 174, 7428-7435} . MccJ25 was purified to homogeneity from the growth medium of a microcin-overproducing Escherichia coli strain by reverse-phase HPLC . Based on amino acid composition and absolute configuration determination, liquid secondary ion and electrospray mass spectrometry, extensive two-dimensional NMR, enzymatic and chemical degradations studies, the structure of MccJ25 was elucidated as a 21-residue peptide, cyclo(-Val1-Gly-Ile-Gly-Thr- Pro-Ile-Ser-Phe-Tyr-Gly-Gly-Gly-Ala-Gly-His-Val-Pro-Glu-Tyr-Phe21- ) . Although MccJ25 showed high resistance to most of endoproteases, linearization by thermolysin occurred from cleavage at the Phe21-Val1 bond and led to a single peptide, MccJ25-L . While MccJ25 exhibited remarkable antibiotic activity towards Salmonella newport and several E . coli strains (minimal inhibitory concentrations ranging between 0.01 and 0.2 microgram.mL-1), the thermolysin-linearized microcin showed a dramatic decrease of the activity, indicating that the cyclic structure is essential for the MccJ25 biological properties . As MccJ25 is ribosomally synthesized as a larger peptide precursor endowed with an N-terminal extremity, the present study shows that removal of this extension and head-tail cyclization of the resulting propeptide are the only post-translational modifications involved in the maturation of MccJ25, that appears as the first cyclic microcin.

Acta Otorrinolaringol Esp, 1999 Jan-Feb, 50(1), 15 - 9
{Antimicrobial therapy in chronic suppurative otitis media}; De Miguel Martinez I et al.; A randomized study was made of 125 patients with chronic middle ear infection . The most frequently isolated microorganisms were: Pseudomonas aeruginosa, Staphylococcus aureus and Enterobacteriaceae . Ciprofloxacin is very active against the microorganisms usually isolated and it has been shown to provide effective therapy in ear infections . In order to study the effectiveness of ciprofloxacin in chronic otitis media, we selected four different treatment groups: oral ciprofloxacin (500 mg/12 h); 0.5 and 0.2% topical solutions of ciprofloxacin (3 drops/8 h), and oral ciprofloxacin plus 0.2% topical solution . Topical polymyxin and neomycin were used as controls . Topical ciprofloxacin (0.2%) was the most effective regimen of those tested for the treatment of chronic otitis media.

Mayo Clin Proc, 1999 Mar, 74(3), 290 - 307
The penicillins; Wright AJ; The penicillin family of antibiotics remains an important part of our antimicrobial armamentarium . In general, these agents have bactericidal activity, excellent distribution throughout the body, low toxicity, and efficacy against infections caused by susceptible bacteria . The initial introduction of aqueous penicillin G for treatment of streptococcal and staphylococcal infections was an important pharmacologic landmark . The emergence of penicillinase-producing Staphylococcus aureus prompted the development of the penicillinase-resistant penicillins (for example, methicillin, oxacillin, and nafcillin), in which an acyl side chain prevented disruption of the beta-lactamase ring . Subsequently, the aminopenicillins (ampicillin, amoxicillin, and bacampicillin) were developed because of the need for gram-negative antimicrobial activity . Their spectrum initially included Escherichia coli, Proteus mirabilis, Shigella, Salmonella, Listeria, Haemophilus, and Neisseria . The search for a penicillin with additional antimicrobial activity against the Enterobacteriaceae and Pseudomonas aeruginosa led to the development of the carboxypenicillins (carbenicillin and ticarcillin) and the ureidopenicillins (mezlocillin, azlocillin, and piperacillin) . Finally, the combination of a beta-lactamase inhibitor (clavulanic acid, sulbactam, or tazobactam) and an aminopenicillin, ticarcillin, or piperacillin has further extended their antibacterial spectra by inhibiting certain beta-lactamases (non-group 1) of resistant bacteria . The development of an ideal penicillin that is rapidly bactericidal, nonsensitizing, nontoxic, bioavailable, and resistant to beta-lactamases and that has a high affinity for penicillin-binding proteins remains the goal.

Zentralbl Veterinarmed B, 1999 Feb, 46(1), 37 - 45
Measurement of the residual contamination of post-weaning facilities for pigs and related risk factors; Madec F et al.; A survey was designed in France to assess residual contamination in post-weaning rooms within the 2 h prior to restocking when all the pigs of the previous batch had been removed (all in-all out) and after application of the 'in use' cleaning procedures . The protocol was based on the results of a pilot study and was considered 'a good compromise' . Special agar plates (Rodac plates) with a prominent agar medium surface were prepared and used to collect the bacteria . They were applied by impression onto the floors and the partitions between the pens . In all, 24 plates were applied per room . The culture medium was VRBG which mainly permits the growth of enterobacteria . The plates were incubated for 24 h (37 degrees C) and the Colony-Forming Units (CFU) counted . After sampling, measurements were made and information collected from the farmer to obtain potential explanations for the resulting microbiological data . The same scientist sampled 129 post-weaning rooms with slatted floors . Of the 3045 plates, 18.4% were negative and 12.8% were heavily colonized (> 300 CFU) . A score combining six criteria based on the counts was produced, and indicated a wide spread of the rooms . The profile of circumstances associated with the different levels of the score was extracted . The following points should be respected to achieve low residual contamination: removal of the slurry from the pit below the slatted floor; damping to be started soon after pig removal; prolonged damping; thorough washing; disinfecting soon after washing; and attention to the recommended dosage of disinfectant . Smooth surfaces were found to be less contaminated than rough ones . It is concluded that cleaning and disinfecting operations must not be considered as minor tasks and should clearly be integrated into the process of pig production.

Infect Immun, 1999 Apr, 67(4), 1736 - 42
Lipopolysaccharides (LPS) of oral black-pigmented bacteria induce tumor necrosis factor production by LPS-refractory C3H/HeJ macrophages in a way different from that of Salmonella LPS; Kirikae T et al.; Some lipopolysaccharide (LPS) preparations from S- or R-form members of the family Enterobacteriaceae and oral black-pigmented bacteria (Porphyromonas gingivalis and Prevotella intermedia) are known to activate LPS-refractory C3H/HeJ macrophages . When contaminating proteins are removed from R-form LPS of Enterobacteriaceae by repurification, however, this ability is lost . In the present study, we investigated the capacity of LPS from P . gingivalis, P . intermedia, Salmonella minnesota, and Salmonella abortusequi to induce production of tumor necrosis factor (TNF) in gamma interferon-primed C3H/HeJ macrophages before and after repurification . P . abortusequi S-LPS was fractionated by centrifugal partition chromatography into two LPS forms: SL-LPS, having homologous long O-polysaccharide chains, and SS-LPS having short oligosaccharide chains . Prior to repurification, all LPS forms except SL-LPS induced TNF production in both C3H/HeJ and C3H/HeN macrophages . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that repurification removed contaminating protein from the preparations, and repurified SS-LPS and S . minnesota Ra-LPS no longer stimulated TNF production in C3H/HeJ macrophages, although C3H/HeN macrophages remained responsive . In contrast, repurified oral bacterial LPS retained the capacity to induce TNF production in C3H/HeJ macrophages . Oral bacterial LPS preparations also were not antagonized by excess inactive, repurified SL-LPS; Ra-LPS; Rhodobacter sphaeroides lipid A, a competitive LPS antagonist, or paclitaxel, an LPS agonist, and they were comparatively resistant to polymyxin B treatment . Nevertheless, oral bacterial LPS was less toxic to D-galactosamine-treated C3H/HeN mice than was LPS from Salmonella . These findings indicate that the active molecule(s) and mode of action of LPS from P . gingivalis and P . intermedia are quite different from those of LPS from Salmonella.

Antibiot Khimioter, 1998, 43(11), 28 - 33
{Etiotropic antibiotic therapy and immunotherapy of patients with pyo-inflammatory processes}; Vasina TA et al.; A 3-year experience was reviewed in the treatment of patients with pyoinflammatory processes (PIP) which developed during the postoperative period in 387 persons with closed injury and multiple penetrating wounds of the chest and stomach complicated by massive hemorrhage . When the PIP was localized in the abdominal cavity, enterobacteria and bacteroides were the main pathogens: 49.4 +/- 2.1 and 32.8 +/- 1.4 per cent, respectively . When the PIP was localized in the thoracic cavity, the most frequent pathogens were staphylococci, Pseudomonas aeruginosa, and enterobacteria: 26.5 +/- 1.4, 24.6 +/- 1.4 and 13.3 +/- 0.8 per cent, respectively . In all the cases high variability of the antibiotic susceptibility of the isolates and predominance of the strains resistant to 5 or more drugs were observed . A suppressive effect of thienam on the immune system was revealed . The immunocorrection in parallel with the antibiotic therapy made it possible to prevent further development of immune deficiency and to recover the bactericidal potency of the phagocyting cells . The use of various physiochemical methods in complex treatment of PIPs is substantiated.

J Mol Evol, 1999 Apr, 48(4), 398 - 407
Synonymous nucleotide divergence and saturation: effects of site-specific variations in codon bias and mutation rates; Berg OG; The synonymous divergence between Escherichia coli and Salmonella typhimurium is explained in a model where there is a large variation between mutation rates at different nucleotide sites in the genome . The model is based on the experimental observation that spontaneous mutation rates can vary over several orders of magnitude at different sites in a gene . Such site-specific variation must be taken into account when studying synonymous divergence and will result in an apparent saturation below the level expected from an assumption of uniform rates . Recently, it has been suggested that codon preference in enterobacteria has a very large site-specific variation and that the synonymous divergence between different species, e.g., E . coli and Salmonella, is saturated . In the present communication it is shown that when site-specific variation in mutation rates is introduced, there is no need to invoke assumptions of saturation and a large variability in codon preference . The same rate variation will also bring average mutation rates as estimated from synonymous sequence divergence into numerical agreement with experimental values.

Appl Microbiol Biotechnol, 1999 Jan, 51(1), 79 - 84
Efficient expression of mosquito-larvicidal proteins in a gram-negative bacterium capable of recolonization in the guts of Anopheles dirus larva; Khampang P et al.; The gram-negative bacterium, An11/2 G1, isolated from the guts of Anopheles dirus mosquito larvae, was identified as Enterobacter amnigenus . The E . amnigenus was able to recolonize in the gut of An . dirus larva but not in those of Aedes aegypti and Culex quinquefasciatus larvae . It was able to float in water for a longer period than Bacillus thuringiensis subsp . israelensis and Bacillus sphaericus . These are desirable characteristics for a delivery vehicle of mosquito-larvicidal toxins for the control of mosquito larvae, and E . amnigenus was therefore used as a host to express the cryIVB gene of B . thuringiensis subsp . israelensis and the binary toxin genes of B . sphaericus . The recombinant E . amnigenus produced a high level of CryIVB protein, which was toxic to larvae of Ae . aegypti and An . dirus . Another E . amnigenus producing the 51-kDa protein of B . sphaericus was toxic to larvae of An . dirus and Cx . quinquefasciatus . The recombinant plasmids were stable in E . amnigenus without the presence of selective pressure for at least 23 generations . The recombinant E . amnigenus should represent a desirable biological agent for controlling mosquito larvae.

Int J Antimicrob Agents, 1999 Jan, 11(1), 59 - 64
The effect of new disinfectant substances on the metabolism of Enterobacter cloacae; Majtan V et al.; The antimicrobial mechanism of 16 new commercially manufactured disinfectant substances on an Enterobacter cloacae strain was studied . The substances tested represent 11 quaternary ammonium salts (QAS) and five combinated QAS with other ingredients . The antimicrobial efficacy was characterized by influencing the growth of bacterial cells expressed by MIC and ED50 values as well as by the inhibition of the incorporation rate of {14C} adenine and {14C} leucine . The disinfectants are divided into three groups according to their efficacy . The first group comprised substances with strong inhibitory effect (MIC 0.006-0.048 mg l(-1)) such as triquart, topax 91, benzalkonium chloride, neoquat S, ID 213, and antibacteric P . The second group represented substances with good antibacterial efficacy (MIC 0.048-0.15 mg l(-1)), and the third group were substances with MIC values up to 0.195-0.39 mg l(-1) . Cetrimide had low activity (MIC 3.12-6.25 mg l(-1)) . The effect of substances studied on the biosynthetic processes expressed by R values (IC50 Ade:IC50 Leu) showed that these values were < 1 except ADL 007 . Much lower IC50 Ade and IC50 Leu values of the disinfectant substances studied suggested interference of these substances with nucleic acid synthesis and proteins synthesis which was expressed by inhibition of both precursors . All substances except cetrimide caused an inhibition of the endogenous respiration . The highest inhibition was caused by benzalkonium chloride . This affected the respiration significantly in the presence of intermediators of the Krebs' cycle (glycerol, aspartate) . The tested substance suppressed the growth of E . cloacae probably through interference with energy-yielding and energy-requiring processes of the cells.

Int J Antimicrob Agents, 1999 Jan, 11(1), 7 - 12
Combination antibiotic therapy versus monotherapy for gram-negative bacteraemia: a commentary; Chow JW et al.; Whether combination antimicrobial therapy is more efficacious than monotherapy for gram-negative bacteraemia remains controversial . Although there are theoretical advantages to combination therapy that are buttressed by in vitro and animal studies, the data from studies of patients with gram-negative bacteraemias have been conflicting . A review of selected clinical studies suggests that combination therapy is associated with improved outcome typically only in severely ill patients and its efficacy may be further limited to those with Pseudomonas aeruginosa, Klebsiella spp . or Enterobacter spp . bacteraemia.

Zhonghua Jie He He Hu Xi Za Zhi, 1997 Aug, 20(4), 208 - 11
{The clinical manifestation and drug sensitive tests of lower respiratory tract infection by enterobacter cloacae . The Pulmonary Infection and Fibrosis Group, Thoracic Society Shanghai Medical Association}
{Postoperative management . Critical care in intra-abdominal infection after surgical intervention}
Montravers P, Lepers S, Popesco D.

Service C d'Anesthesie-Reanimation, Groupe Hospitalier Sud-Salouel, Amiens . pmontrav@planete.net

UNDERESTIMATED FREQUENCY: Post-operative intraabdominal infections usually appear as abscesses or injury of the bowel, either alone or in combination . These complications of frequently underestimated frequency are characterized by high mortality . Improvement of their prognosis is obtained by early recognition of the complication and a multidisciplinary approach . ALARM SIGNS: In a patient who recently underwent abdominal surgery, the onset of abnormal signs must be considered as an alarm which imposes ruling out intraabdominal complications . Unexplained multiple organ failure or septic shock in the post-operative period of intraabdominal surgery must lead to considering explorative laparotomy . THERAPEUTICS: Etiologic treatment must be ideal and total from the first reoperation . Antibiotic therapy administered from the surgical reoperation must be different from previous treatments . This treatment is aimed at eradicating enterobacteriaceae, non-fermenting Gram negative aerobes, Gram positive cocci, anaerobes and fungi.

Bull Math Biol, 1999 Jan, 61(1), 85 - 111
Bayesian predictive identification and cumulative classification of bacteria; Gyllenberg M et al.; In this paper we give a mathematically precise formulation of an old idea in bacterial taxonomy, namely cumulative classification, where the taxonomy is continuously updated and possibly augmented as new strains are identified . Our formulation is based on Bayesian predictive probability distributions . The criterion for founding a new taxon is given a firm theoretical foundation based on prediction and it is given a clear-cut interpretation . We formulate an algorithm for cumulative classification and apply it to a large database of bacteria belonging to the family Enterobacteriaceae . The resulting taxonomy makes microbiological sense.

Neurosurgery, 1999 Mar, 44(3), 636 - 42; discussion 642-3
Long-term remission of malignant brain tumors after intracranial infection: a report of four cases; Bowles AP Jr et al.; OBJECTIVE: This report describes four patients with malignant brain tumors in whom regression or cure seems to be related to infection with bacteria . METHODS: An analysis of the four clinical cases reported and a review of the literature produced a comprehensive body of both experimental and clinical data concerning the antineoplastic properties of bacteria . RESULTS: Although direct oncolytic effects from bacteria have been suggested, immune adjuvant responses to tumor suppression are emphasized . In one of our patients, infiltration of numerous granulocytes and lymphocytes into the tumor at the time of initial surgery was observed, suggesting that a spontaneous immune reaction had begun . Also, in two other patients, tumor aggression occurred in association with a bacterial process that was not in direct contact with the tumor . In three of the cases described, Enterobacter aerogenes was recovered from the microbial cultures . Whether the presence of this organism was coincidental or whether this organism plays an important role in tumor defense is not known; however, a specific cross-reactive immunological attack to the tumor is suggested . CONCLUSION: The case histories presented in conjunction with the relevant literature reviewed support the concept that microbial infections may influence immune responses in brain tumor defense.

Curr Microbiol, 1999 Apr, 38(4), 217 - 23
Fingerprinting of mixed bacterial strains and BIOLOG gram-negative (GN) substrate communities by enterobacterial repetitive intergenic consensus sequence-PCR (ERIC-PCR); Di Giovanni GD et al.; PCR-based genomic fingerprinting by use of enterobacterial repetitive intergenic consensus primers (ERIC-PCR) was evaluated for its use in fingerprinting DNA of mixed Gram-negative bacterial strains and BIOLOG Gram-negative (GN) microplate substrate communities . ERIC-PCR fingerprints of six different pure bacterial strains and a combined mixture of the strains were compared with fingerprints obtained by two more established methods: amplified ribosomal DNA restriction analysis (ARDRA) and random amplified polymorphic DNA analysis (RAPD-PCR) . The ERIC-PCR fingerprint of the mixed strains was highly reproducible and was more species-specific and representative of the individual strain fingerprints than the ARDRA and RAPD-PCR fingerprints, respectively . ERIC-PCR fingerprinting of model and rhizosphere BIOLOG GN substrate communities also provided clearly distinguishable fingerprints . Results of this study suggest that ERIC-PCR represents a rapid and highly discriminating method for fingerprinting DNA of mixed Gram-negative bacterial strains and BIOLOG GN substrate communities.

Pediatr Emerg Care, 1999 Feb, 15(1), 40 - 2
Etiology of septic arthritis in children: an update for the 1990s; Luhmann JD et al.; OBJECTIVE: To establish the etiology of septic arthritis in children after implementation of HIB immunization guidelines . METHODS: A retrospective review of all charts with a discharge diagnosis of septic arthritis (ICD-9: 711) from January 1991 to December 1996 at St . Louis Children's Hospital was conducted . RESULTS: Sixty-four patients (male = 58%) were identified, whose median age was 6.0 years . Twenty-one children (33%) were misdiagnosed on initial presentation . An organism was isolated in 38 (59%) of cases . The predominant organisms were Staphylococcus aureus (10 isolates), Group A Streptococcus (4), Enterobacter species (4), Kingella kingae (3), Neisseria meningitides (3), Streptococcus pneumoniae (2), Neisseria gonorrhoeae (2), Candida (2), Staphylococcus epidermidis (2) . The only isolate of Haemophilus influenzae type B was in 1992 in an unimmunized 14 month old . CONCLUSIONS: These data confirm Staphylococcus aureus as a frequent pathogen and suggest that H influenzae type B is no longer the predominant isolate in young children with septic arthritis . In addition, early septic arthritis in children is frequently misdiagnosed on initial evaluation.

Folia Microbiol (Praha), 1998, 43(6), 683 - 6
Type I beta-lactamases of Enterobacter cloacae and resistance to beta-lactam antibiotics; Tejedor-Junco MT et al.; The interaction of type-I beta-lactamases from Enterobacter cloacae with diverse beta-lactam compounds was examined . The ability of penicillin and cefoxitin to induce beta-lactamase production in this strain was assessed . The effect of beta-lactamase inhibitors was measured on beta-lactamase extracts and on intact cells . E . cloacae 78 strain is a stably derepressed mutant showing limited susceptibility to a number of antibiotics except imipenem . Imipenem would therefore be the appropriate choice for therapy of infections caused by stably derepressed mutants of Enterobacter sp . producing type-I beta-lactamases.

Folia Microbiol (Praha), 1998, 43(6), 563 - 82
Colicins--exocellular lethal proteins of Escherichia coli; Smarda J et al.; Colicins are toxic exoproteins produced by bacteria of colicinogenic strains of Escherichia coli and some related species of Enterobacteriaceae, during the growth of their cultures . They inhibit sensitive bacteria of the same family . About 35% E . coli strains appearing in human intestinal tract are colicinogenic . Synthesis of colicins is coded by genes located on Col plasmids . Until now more than 34 types of colicins have been described, 21 of them in greater detail, viz . colicins A, B, D, E1-E9, Ia, Ib, JS, K, M, N, U, 5, 10 . In general, their interaction with sensitive bacteria includes three steps: (1) binding of the colicin molecule to a specific receptor in the bacterial outer membrane; (2) its translocation through the cell envelope; and (3) its lethal interaction with the specific molecular target in the cell . The classification of colicins is based on differences in the molecular events of these three steps.

Kekkaku, 1999 Jan, 74(1), 19 - 25
{Evaluation of Mycobacterium kansasii isolates from a clinical laboratory in a city hospital}; Tazawa S et al.; Fifteen isolates of Mycobacterium kansasii in Showa University Fujigaoka Hospital between 1982 and 1995 were investigated . Comparing by gender, 13 were isolated from male patients and only two were isolated from female patients . The average of cases was 48 years old and 14 out of 15 cases (93%) were isolated from respiratory tract specimens . The rate of the smear- and culture-positives was 64%, which was significantly higher than that (26%) of M . avium complex (p < 0.01 by chi 2 test) . All 4 isolates were susceptible to rifampicin (10 micrograms/ml) by drug susceptibility testing using Ogawa egg medium, and only 1 was resistant to ethambutol (2.5 micrograms/ml) . Seven out of 10 patients whose medical record was available were diagnosed as pulmonary infection with M . kansasii . Two out of 4 patients with primary infection type had underlying diseases such as diabetes mellitus and leukemia, while the remaining two patients did not have any underlying disease . Two out of 3 patients with secondary infection type had a medical history of tuberculosis and the remaining 1 patient had infected pulmonary cyst . Such as Pseudomonas aeruginosa, Enterobacter aerogenes and Flavobacterium spp., and Branhamella catarrhalis, associated with M . kansasii, bacteria more than 10(7) cfu/ml were isolated from the sputa of 3 patients with leukemia, infected pulmonary cyst and post-tuberculosis, respectively . M . kansasii, Stenotrophomonas maltophilia (10(7) cfu/ml) and Candida albicans were detected from the sputum of 1 patient with nephrosis, for which steroid (predonin) and antibiotics (piperacillin and latamoxef) were administrated, however, this patient was not diagnosed as a case of M . kansasii infection . These findings suggest the fact that M . kansasii inhabits among compromised hosts of a city hospital.

J Appl Microbiol, 1999 Feb, 86(2), 221 - 5
Study of the micro-organisms associated with the fermented bread (khamir) produced from sorghum in Gizan region, Saudi Arabia; Gassem MA; Traditional bread (khamir) was made from sorghum flour of two local varieties, Bayadh and Hamra . The bread was prepared by mixing the sorghum flour with water and spices (onion, garlic, lemon juice and fenugreek) in a 1:0.8 (w/w) ratio and fermented for 24 h at 30 degrees C . Two other fermentations were carried out using an inoculum from the previous fermentation . The micro-organisms were isolated from different plates and identified using different characterization systems . Both total bacterial populations and lactic acid bacteria increased with fermentation time and reached the highest number at 16 h (first fermentation) and at 8 h (second and third fermentation) . The content of lactic acid was increased with time to reach 1.2%, but the increase was higher for the second and third fermentations (1.6% each) . The pH dropped with time from 6.77 to 4.35 in the first fermentation and from 6.65 to 4.18, and 6.57-3.93, in the second and third fermentations, respectively . The microorganisms, which were isolated and characterized during the 24 h fermentation, included: bacteria (Pediococcus pentosaceus, Lactobacillus brevis, Lact . lactis subsp . lactis, Lact . cellobiosus, Klebsiella oxytoca, Kl . pneumoniae, Enterobacter aerogenes, Ent . sakazakii, Serratia marcescens and Ser . odourifera), moulds (Penicillium sp., Rhizopus sp., Aspergillus niger, Alternaria sp., Fusarium sp . and Mucor sp.) and yeasts (Candida parapsilosis, C . orvegnsis and Rhodotorula glutinis).

Antimicrob Agents Chemother, 1999 Mar, 43(3), 686 - 9
Many class I integrons comprise distinct stable structures occurring in different species of Enterobacteriaceae isolated from widespread geographic regions in Europe; Martinez-Freijo P et al.; Three sizes of inserted regions of DNA (800, 1,000, and 1,500 bp) were shown to be common among class I integrons in unrelated clinical isolates of Enterobacteriaceae from different European hospitals . Sequencing showed that 800-bp inserted regions comprised identical sequences including aacA4, that 1,000-bp inserted regions included aadA, and that 1,500-bp inserted regions included dfrI and aadA1, irrespective of host species and geographic origin . In addition promoter sequences were mostly identical for each size class . These data suggest that inserted gene cassettes and promoter regions of integrons are conserved and stable, with resistance genes transferred more often as part of the entire integron structure than as individual gene cassettes.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 630 - 3
Use of an isogenic Escherichia coli panel to design tests for discrimination of beta-lactamase functional groups of Enterobacteriaceae; Ehrhardt AF et al.; A study was designed to determine if an isogenic panel of Escherichia coli strains containing many different beta-lactamases could be used for the preliminary screening of a large number of beta-lactam agents to identify which might be most useful in the development of a definitive test for specific beta-lactamases found among the members of family Enterobacteriaceae . The susceptibilities of 46 strains, comprising the isogenic panel, to expanded-spectrum cephalosporins, cephamycins, and aztreonam were determined in the presence and absence of beta-lactamase inhibitors in broth microdilution tests . The results indicated that strains producing extended-spectrum beta-lactamases (ESBLs) could be distinguished from strains producing other Bush-Jacoby-Medeiros functional group 2 or group 1 beta-lactamases . For strains producing group 1 beta-lactamases, cefpodoxime and ceftazidime MICs were > or = 4 micrograms/ml and addition of clavulanate did not reduce the MICs more than fourfold . For strains producing group 2 enzymes other than ESBLs, cefpodoxime and ceftazidime MICs were < or = 2 micrograms/ml . With a single exception (ceftazidime for the strain producing SHV-3), among strains producing ESBLs, cefpodoxime and ceftazidime MICs were > or = 4 micrograms/ml and addition of clavulanate reduced the MICs by more than eightfold . Cephamycins could also be used to discriminate between strains producing group 1 beta-lactamases and ESBLs, since only the former required cefotetan concentrations as high as 8 micrograms/ml or cefoxitin concentrations of > 16 micrograms/ml for inhibition . Other cephalosporins provided some discrimination between the various beta-lactamase producers, although they were not as reliable as either cefpodoxime or ceftazidime . These results indicate the utility of an isogenic panel for identification of candidate drugs among many for further testing with clinical isolates of the family Enterobacteriaceae to determine the best agents for detection of specific beta-lactamases in this family.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 543 - 8
Structure-function studies of Ser-289 in the class C beta-lactamase from Enterobacter cloacae P99; Trepanier S et al.; Site-directed mutagenesis of Ser-289 of the class C beta-lactamase from Enterobacter cloacae P99 was performed to investigate the role of this residue in beta-lactam hydrolysis . This amino acid lies near the active site of the enzyme, where it can interact with the C-3 substituent of cephalosporins . Kinetic analysis of six mutant beta-lactamases with five cephalosporins showed that Ser-289 can be substituted by amino acids with nonpolar or polar uncharged side chains without altering the catalytic efficiency of the enzyme . These data suggest that Ser-289 is not essential in the binding or hydrolytic mechanism of AmpC beta-lactamase . However, replacement by Lys or Arg decreased by two- to threefold the kcat of four of the five beta-lactams tested, particularly cefoperazone, cephaloridine, and cephalothin . Three-dimensional models of the mutant beta-lactamases revealed that the length and positive charge of the side chain of Lys and Arg could create an electrostatic linkage to the C-4 carboxylic acid group of the dihydrothiazine ring of the acyl intermediate which could slow the deacylation step or hinder release of the product.

Antimicrob Agents Chemother, 1999 Mar, 43(3), 460 - 4
In vivo activities of peptidic prodrugs of novel aminomethyl tetrahydrofuranyl-1 beta-methylcarbapenems; Weiss WJ et al.; A series of novel aminomethyl tetrahydrofuranyl (THF)-1 beta-methylcarbapenems which have excellent broad-spectrum antibacterial activities exhibit modest efficacies against acute lethal infections (3.8 mg/kg of body weight against Escherichia coli and 0.9 mg/kg against Staphylococcus aureus) in mice when they are administered orally . In an effort to improve the efficacies of orally administered drugs through enhanced absorption by making use of a peptide-mediated transport system, several different amino acids were added at the aminomethyl THF side chains of the carbapenem molecules . The resulting peptidic prodrugs with L-amino acids demonstrated improved efficacy after oral administration, while the D forms were less active than the parent molecules . After oral administration increased (3 to 10 times) efficacy was exhibited with the alanine-, valine-, isoleucine-, and phenylalanine-substituted prodrugs against acute lethal infections in mice . Median effective doses (ED50s) of < 1 mg/kg against infections caused by S . aureus, E . coli, Enterobacter cloacae, or penicillin-susceptible Streptococcus pneumoniae were obtained after the administration of single oral doses . Several of the peptidic prodrugs were efficacious against Morganella morganii, Serratia marcescens, penicillin-resistant S . pneumoniae, extended-spectrum beta-lactamase-producing Klebsiella pneumoniae, and E . coli infections, with ED50s of 1 to 14 mg/kg by oral administration compared with ED50s of 14 to > 32 mg/kg for the parent molecules . In general, the parent molecules demonstrated greater efficacy than the prodrugs against these same infections when the drugs were administered by the subcutaneous route . The parent molecule was detectable in the sera of mice after oral administration of the peptidic prodrugs.

Epidemiol Infect, 1998 Dec, 121(3), 587 - 98
High turnover rate of Escherichia coli strains in the intestinal flora of infants in Pakistan; Adlerberth I et al.; The Escherichia coli flora of infants in developed countries is dominated by one or a few strains which persist for prolonged periods of time, but no longitudinal studies have been performed in developing countries . To this end, we studied the rectal enterobacterial flora in 22 home-delivered Pakistani infants during their first 6 months of life . Three colonies were isolated and species typed on each of 11 sampling occasions . E . coli isolates were strain typed using electromorphic typing of cytoplasmic enzymes, and their O serogroups were determined . There was a very rapid turnover of enterobacterial strains in the rectal flora of individual infants . On average, 8.5 different E . coli strains were found per infant, and several biotypes of other enterobacteria . Less than 50% of the infants were colonized with E . coli from their mothers, but strains of maternal origin were four times more likely to persists in the infants' flora than other E . coli strains . Enterobacteria other than E . coli were always of non-maternal origin, and Enterobacter cloacae and Klebsiella pneumoniae biotypes recovered from contaminated feeds were later identified in the infants' rectal flora . An early colonization with klebsiella or enterobacter was significantly associated with diarrhoea during the neonatal period, although these bacteria were not likely to be the cause of the disease . The results suggest that poor hygienic conditions result in an unstable and diverse enterobacterial flora, which may influence infant health.

J Food Prot, 1999 Feb, 62(2), 146 - 51
Decontamination of beef carcass surface tissue by steam vacuuming alone and combined with hot water and lactic acid sprays; Castillo A et al.; Hot beef carcass surface regions (outside round, brisket, and clod) contaminated with feces spread over a 5-cm2 (1-in2) area were cleaned using a steam-vacuum spot-cleaning system alone or combined with subsequent sanitizing treatments of hot water (95 degrees C at the nozzle), or warm (55 degrees C) 2% lactic acid spray, or combinations of these two sanitizing methods . These treatments were compared for effectiveness in reducing aerobic plate counts (APC) and counts of Enterobacteriaceae, total coliforms, thermotolerant coliforms, and Escherichia coli . All treatments significantly reduced the numbers of each group of bacteria on beef carcass surfaces . However, reductions obtained by steam vacuuming were significantly smaller than those obtained by a combination of steam vacuuming with any sanitizing treatment . No differences in bacterial reductions were observed between different carcass surface regions . Steam vacuuming reduced the number of different indicator organisms tested by ca . 3.0 log cycles but also spread the bacterial contamination to areas of the carcass surface adjacent to the contaminated sites . This relocated contamination after steam vacuuming was most effectively reduced by spraying with hot water and then lactic acid . This combined treatment consistently reduced the numbers of Enterobacteriaceae, total and thermotolerant coliforms, and E . coli to undetectable levels (<1.0 log10 CFU/cm2) on areas outside the initial 5-cm2 inoculated areas.

Mol Microbiol, 1999 Jan, 31(2), 557 - 67
Analysis of the SlyA-controlled expression, subcellular localization and pore-forming activity of a 34 kDa haemolysin (ClyA) from Escherichia coli K-12; Ludwig A et al.; Escherichia coli K-12 harbours a chromosomal gene, clyA (sheA, hlyE), that encodes a haemolytic 34 kDa protein . Recombinant E . coli overexpressing the cloned clyA gene accumulated this haemolysin in the periplasm and released only very small amounts of it into the external medium . The secretion of ClyA was confined to the log phase and paralleled by the partial release of several other periplasmic proteins . Sequencing of ClyA revealed the translational start point of the clyA gene and demonstrated that the clyA gene product is not N-terminally processed during transport . The transcription of clyA from its native promoter region was positively controlled by SlyA, a regulatory protein found in E . coli, Salmonella typhimurium and other Enterobacteriaceae . SlyA-controlled transcription started predominantly 72 bp upstream from clyA, as shown by primer extension . The corresponding putative promoter contains an unusual -10 sequence (TATGAAT) that is separated from a conventional -35 sequence by a GC-rich spacer . Site-directed deletion of the G in the -10 sequence abrogated the SlyA requirement for strong ClyA production, whereas a reduction in the G + C content of the spacer diminished the capability of SlyA to activate the clyA expression . Osmotic protection assays and lipid bilayer experiments suggested that ClyA forms stable, moderately cation-selective transmembrane pores that have a diameter of about 2.5-3 nm.

Mol Microbiol, 1999 Jan, 31(2), 473 - 87
The sodium ion translocating glutaconyl-CoA decarboxylase from Acidaminococcus fermentans: cloning and function of the genes forming a second operon; Braune A et al.; Glutaconyl-CoA decarboxylase from Acidaminococcus fermentans (clostridal cluster IX), a strict anaerobic inhabitant of animal intestines, uses the free energy of decarboxylation (delta G(o) approximately -30 kJ mol-1) in order to translocate Na+ from the inside through the cytoplasmic membrane . The proton, which is required for decarboxylation, most probably comes from the outside . The enzyme consists of four different subunits . The largest subunit, alpha or GcdA (65 kDa), catalyses the transfer of CO2 from glutaconyl-CoA to biotin covalently attached to the gamma-subunit, GcdC . The beta-subunit, GcdB, is responsible for the decarboxylation of carboxybiotin, which drives the Na+ translocation (approximate K(m) for Na+ 1 mM), whereas the function of the smallest subunit, delta or GcdD, is unclear . The gene gcdA is part of the 'hydroxyglutarate operon', which does not contain genes coding for the other three subunits . This paper describes that the genes, gcdDCB, are transcribed in this order from a distinct operon . The delta-subunit (GcdD, 12 kDa), with one potential transmembrane helix, probably serves as an anchor for GcdA . The biotin carrier (GcdC, 14 kDa) contains a flexible stretch of 50 amino acid residues (A26-A75), which consists of 34 alanines, 14 prolines, one valine and one lysine . The beta-subunit (GcdB, 39 kDa) comprising 11 putative transmembrane helices shares high amino acid sequence identities with corresponding deduced gene products from Veillonella parvula (80%, clostridial cluster IX), Archaeoglobus fulgidus (61%, Euryarchaeota), Propionigenium modestum (60%, clostridial cluster XIX), Salmonella typhimurium (51%, enterobacteria) and Klebsiella pneumoniae (50%, enterobacteria) . Directly upstream of the promoter region of the gcdDCB operon, the 3' end of gctM was detected . It encodes a protein fragment with 73% sequence identity to the C-terminus of the alpha-subunit of methylmalonyl-CoA decarboxylase from V . parvula (MmdA) . Hence, it appears that A . fermentans should be able to synthesize this enzyme by expression of gctM together with gdcDCB, but methylmalonyl-CoA decarboxylase activity could not be detected in cell-free extracts . Earlier observations of a second, lower affinity binding site for Na+ of glutaconyl-CoA decarboxylase (apparent K(m) 30 mM) were confirmed by identification of the cysteine residue 243 of GcdB between the putative hellces VII and VIII, which could be specifically protected from alkylation by Na+ . The alpha-subunit was purified from an overproducing Escherichia coli strain and was characterized as a putative homotrimer able to catalyse the carboxylation of free biotin.

J Dairy Sci, 1999 Jan, 82(1), 80 - 5
Recurrent clinical mastitis caused by Escherichia coli in dairy cows; Dopfer D et al.; In this study, the occurrence of persistent intramammary infections caused by Escherichia coli with recurrent episodes of clinical mastitis caused by E . coli are described for a cohort of 300 Dutch dairy herds . Calculations on the recurrent episodes were based on data collected by dairy farmers . The genotype of the E . coli strains was determined by means of a polymerase chain reaction using enterobacterial repetitive intergenic consensus (ERIC) primers, resulting in a DNA fingerprint . Quarters in which the same E . coli genotype was found were considered to be persistently infected . In 4.77% of all episodes of clinical mastitis caused by E . coli, persistent intramammary infections caused by the same E . coli genotype were found . Based on the occurrence of the same genotypes, we concluded that, in 2.98% of all episodes, transmission of E . coli strains among quarters within one cow might have occurred . In 13.04% of all episodes of clinical mastitis caused by E . coli in the study, different E . coli genotypes were isolated from recurrent episodes of clinical mastitis within the same cow, indicating that these cows were highly susceptible to recurrent intramammary infections caused by E . coli.

Microb Drug Resist, 1998 Winter, 4(4), 289 - 99
Antibiotic resistance in Escherichia coli of the normal intestinal flora of swine; Sunde M et al.; Twelve hundred enterobacterial Escherichia coli isolates of porcine origin were screened phenotypically for antibiotic resistance . The bacteria were isolated from 10 herds of swine with different histories of exposure to antimicrobial agents for therapeutic purposes . The bacterial isolates were part of the normal bacterial flora of the intestines of the animals because they were isolated from healthy individuals . The strains were tested for phenotypic antibiotic resistance against sulfonamides, trimethoprim, streptomycin, ampicillin, neomycin, chloramphenicol, and tetracycline . Resistance against streptomycin was found to be most common, followed by resistance against sulfonamides and tetracycline . The highest number of resistant bacteria was found in herds where the use of antimicrobial agents was considered to be high . A selection of multiresistant bacterial isolates were further genetically characterized by hybridization with probes specific for the antibiotic resistance genes; sulI, sulII, dfrI, dfrIIb, dfrIX, and the class A, B, C, and D tetracycline resistance determinants . A PCR was developed and used for detection of the strA-strB gene pair encoding streptomycin resistance in gram-negative bacteria . The strA-strB gene pair was the most frequent resistance determinant in the isolates examined . This study indicates that nonpathogenic E . coli from swine may represent a considerable reservoir of antibiotic resistance genes that might be transferable to pathogens.

J Clin Microbiol, 1999 Mar, 37(3), 544 - 7
Comparison of agar dilution, disk diffusion, MicroScan, and Vitek antimicrobial susceptibility testing methods to broth microdilution for detection of fluoroquinolone-resistant isolates of the family Enterobacteriaceae; Steward CD et al.; Fluoroquinolone resistance appears to be increasing in many species of bacteria, particularly in those causing nosocomial infections . However, the accuracy of some antimicrobial susceptibility testing methods for detecting fluoroquinolone resistance remains uncertain . Therefore, we compared the accuracy of the results of agar dilution, disk diffusion, MicroScan Walk Away Neg Combo 15 conventional panels, and Vitek GNS-F7 cards to the accuracy of the results of the broth microdilution reference method for detection of ciprofloxacin and ofloxacin resistance in 195 clinical isolates of the family Enterobacteriaceae collected from six U.S . hospitals for a national surveillance project (Project ICARE {Intensive Care Antimicrobial Resistance Epidemiology}) . For ciprofloxacin, very major error rates were 0% (disk diffusion and MicroScan), 0.9% (agar dilution), and 2.7% (Vitek), while major error rates ranged from 0% (agar dilution) to 3.7% (MicroScan and Vitek) . Minor error rates ranged from 12.3% (agar dilution) to 20.5% (MicroScan) . For ofloxacin, no very major errors were observed, and major errors were noted only with MicroScan (3.7% major error rate) . Minor error rates ranged from 8.2% (agar dilution) to 18.5% (Vitek) . Minor errors for all methods were substantially reduced when results with MICs within +/-1 dilution of the broth microdilution reference MIC were excluded from analysis . However, the high number of minor errors by all test systems remains a concern.

Mol Microbiol, 1999 Jan, 31(1), 319 - 29
The structural and functional organization of H-NS-like proteins is evolutionarily conserved in gram-negative bacteria; Bertin P et al.; The structural gene of the H-NS protein, a global regulator of bacterial metabolism, has been identified in the group of enterobacteria as well as in closely related bacteria, such as Erwinia chrysanthemi and Haemophilus influenzae . Isolated outside these groups, the BpH3 protein of Bordetella pertussis exhibits a low amino acid conservation with H-NS, particularly in the N-terminal domain . To obtain information on the structure, function and/or evolution of H-NS, we searched for other H-NS-related proteins in the latest databases . We found that HvrA, a trans-activator protein in Rhodobacter capsulatus, has a low but significant similarity with H-NS and H-NS-like proteins . This Gram-negative bacterium is phylogenetically distant from Escherichia coli . Using theoretical analysis (e.g . secondary structure prediction and DNA binding domain modelling) of the amino acid sequence of H-NS, StpA (an H-NS-like protein in E . coli), BpH3 and HvrA and by in vivo and in vitro experiments (e.g . complementation of various H-NS-related phenotypes and competitive gel shift assay), we present evidence that these proteins belong to the same class of DNA binding proteins . In silico analysis suggests that this family also includes SPB in R . sphaeroides, XrvA in Xanthomonas oryzae and VicH in Vibrio cholerae . These results demonstrate that proteins structurally and functionally related to H-NS are widespread in Gram-negative bacteria.

Mol Microbiol, 1999 Jan, 31(1), 133 - 42
Transient transcriptional activation of the Incl1 plasmid anti-restriction gene (ardA) and SOS inhibition gene (psiB) early in conjugating recipient bacteria; Althorpe NJ et al.; The ardA gene of the enterobacterial plasmid CollbP-9 acts to alleviate restriction of DNA by type I systems, while psiB inhibits induction of the bacterial SOS response . Both genes are transferred early in a round of bacterial conjugation as part of the plasmid leading region . We report here that ardA and psiB are transcribed transiently after their conjugative transport into the recipient cell . Transcript levels, monitored by competitive reverse transcription-polymerase chain reaction (RT-PCR) amplification of RNA templates, started to increase about 5 min after the initiation of conjugation in a cell population and probably before the first round of plasmid transfer was completed . Genetic evidence is given that the expression of ardA and psiB is activated when the genes enter the recipient cell on the transferring plasmid strand . It is proposed that these and other leading region genes function to promote the establishment of the immigrant plasmid in the new host and are expressed by transcription from promoters active only in single-stranded DNA.

Mol Microbiol, 1999 Jan, 31(1), 89 - 101
When drug inactivation renders the target irrelevant to antibiotic resistance: a case story with beta-lactams; Lakaye B et al.; By challenging the efficiency of some of our most useful antimicrobial weapons, bacterial antibiotic resistance is becoming an increasingly worrying clinical problem . A good antibiotic is expected to exhibit a high affinity for its target and to reach it rapidly, while escaping chemical modification by inactivating enzymes and elimination by efflux mechanisms . A study of the behaviour of a beta-lactamase-overproducing mutant of Enterobacter cloacae in the presence of several penicillins and cephalosporins showed that the minimum inhibitory concentration (MIC) values for several compounds were practically independent of the sensitivity of the target penicillin binding protein (PBP), even for poor beta-lactamase substrates . This apparent paradox was explained by analysing the equation that relates the antibiotic concentration in the periplasm to that in the external medium . Indeed, under conditions that are encountered frequently in clinical isolates, the factor characterizing the PBP sensitivity became negligible . The conclusions can be extended to all antibiotics that are sensitive to enzymatic inactivation and efflux mechanisms and must overcome permeability barriers . It would be a grave mistake to neglect these considerations in the design of future antibacterial chemotherapeutic agents.

J Clin Microbiol, 1999 Mar, 37(3), 766 - 8
ABC medium, a new chromogenic agar for selective isolation of Salmonella spp; Perry JD et al.; We describe a new chromogenic agar medium, ABC medium (alphabeta-chromogenic medium), which includes two substrates, 3, 4-cyclohexenoesculetin-beta-D-galactoside and 5-bromo-4-chloro-3-indolyl-alpha-D-galactopyranoside, to facilitate the selective isolation of Salmonella spp . This medium exploits the fact that Salmonella spp . may be distinguished from other members of the family Enterobacteriaceae by the presence of alpha-galactosidase activity in the absence of beta-galactosidase activity . A total of 1, 022 strains of Salmonella spp . and 300 other gram-negative strains were inoculated onto this medium . Of these, 1,019 (99.7%) strains of Salmonella spp . produced a characteristic green colony, whereas only 1 strain (0.33%) of non-Salmonella produced a green colony . A total of 283 stool samples were cultured onto desoxycholate citrate (DC) agar and ABC medium by direct inoculation and after selective enrichment in selenite broth . Overall, the sensitivity and specificity were superior for ABC medium (100 and 90.5%, respectively) than for DC agar (88 and 26.9%, respectively) . We conclude that ABC medium offers a high degree of specificity for the detection of Salmonella spp . in stool samples.

Biosci Biotechnol Biochem, 1998 Dec, 62(12), 2357 - 63
Alanine dehydrogenase from Enterobacter aerogenes: purification, characterization, and primary structure; Chowdhury EK et al.; Alanine dehydrogenase {EC 1 . 4 . 1 . 1} was purified to homogeneity from a crude extract of Enterobacter aerogenes ICR 0220 . The enzyme had a molecular mass of about 245 kDa and consisted of six identical subunits . The enzyme showed maximal activity at about pH 10.9 for the deamination of L-alanine and at about pH 8.7 for the amination of pyruvate . The enzyme required NAD+ as a coenzyme . Analogs of NAD+, deamino-NAD+ and nicotinamide guanine dinucleotide served as coenzymes . Initial-velocity and product inhibition studies suggested that the deamination of L-alanine proceeded through a sequential ordered binary-ternary mechanism . NAD+ bound first to the enzyme, followed by L-alanine, and the products were released in the order of ammonia, pyruvate, and NADH . The Km were 0.47 mM for L-alanine, 0.16 mM for NAD+, 0.22 mM for pyruvate, 0.067 mM for NADH, and 66.7 mM for ammonia . The Km for L-alanine was the smallest in the alanine dehydrogenases studied so far . The enzyme gene was cloned into Escherichia coli JM109 cells and the nucleotides were sequenced . The deduced amino acid sequence was very similar to that of the alanine dehydrogenase from Bacillus subtilis . However, the Enterobacter enzyme has no cysteine residue . In this respect, the Enterobacter enzyme is different from other alanine dehydrogenases.

Drugs, 1999 Jan, 57(1), 81 - 91
Biliary tract infections: a guide to drug treatment; Westphal JF et al.; Initial therapy of acute cholecystitis and cholangitis is directed towards general support of the patient, including fluid and electrolyte replacement, correction of metabolic imbalances and antibacterial therapy . Factors affecting the efficacy of antibacterial therapy include the activity of the agent against the common biliary tract pathogens and pharmacokinetic properties such as tissue distribution and the ratio of concentration in both bile and serum to the minimum inhibitory concentration for the expected micro-organism . Antimicrobial therapy is usually empirical . Initial therapy should cover the Enterobacteriaceae, in particular Escherichia coli . Activity against enterococci is not required since their pathogenicity in biliary tract infections remains unclear . Coverage of anaerobes, in particular Bacteroides spp., is warranted in patients with previous bile duct-bowel anastomosis, in the elderly and in patients in serious clinical condition . In patients with acute cholecystitis or cholangitis of moderate clinical severity, monotherapy with a ureidopenicillin--mezlocillin or piperacillin--is at least as effective as the combination of ampicillin plus aminoglycoside . In severely ill patients with septicaemia, an antibacterial combination is preferable . Therapy with aminoglycosides, mostly for Pseudomonas aeruginosa-related infections, should not exceed a few days because the risk of nephrotoxicity seems to be increased during cholestasis . Relief of biliary obstruction is mandatory, even if there is clinical improvement with conservative therapy, because cholangitis is most likely to recur with continued obstruction . Emergency invasive therapy is reserved for patients who fail to show a clinical response to antibacterial therapy within the first 36 to 48 hours or for those who deteriorate after an initial clinical improvement . Immediate surgery is indicated for gangrenous cholecystitis and perforation with peritonitis . Long-term administration of antibacterials is required for recurrent cholangitis, as seen in bile duct-bowel anastomosis . Oral cotrimoxazole (trimethoprim/sulfamethoxazole) is the preferred agent . Wound infection rates after biliary tract surgery can be significantly reduced by preoperative administration of prophylactic antibacterials . Newer generation beta-lactams have not proven to be of greater benefit than older agents such as cefuroxime or cefazolin . Antibacterial prophylaxis before endoscopic retrograde cholangiopancreatography (ERCP) should be reserved for patients with obstructive jaundice, since the risk of infectious complications seems to be strongly associated with this clinical condition . Failure to achieve full biliary drainage is the most important factor in predicting septicaemia, and prophylaxis should be prolonged until the bile duct is unobstructed . Piperacillin, cefazolin, cefuroxime, cefotaxime and ciprofloxacin are effective for this indication.

Presse Med, 1999 Jan 9, 28(1), 20 - 8
{Optimizing antibiotic therapy in a hospital setting}; Guerin JM; Optimal use of antibiotics in hospitalized patients raises several problems . i) Does the patient really have an infection treatable with antibiotics? Currently, there are no clinical or biological data which can resolve this question with sufficient sensitivity and specificity . ii) Are microbial samples warranted before starting treatment? All bacteria isolated from cerebrospinal, ascitis, pleural or articular fluids are pathogens whereas a quantitative assessment is required for bacteria isolated from the upper or lower respiratory tract . iii) If an antibiotic is needed should a single drug or a multiple drug regimen be prescribed? Twenty years ago two-drug regimens were necessary . Synergism and better spectrum were the keystones of two-drug therapy . Today, single-drug regimens are sufficient except in case of Staphylococcus, Pseudomonas or some Enterobacteriacae infections . iv) Which administration route is best? In hospitalized patients, the parenteral route is generally used with a rapid switch to oral administration, usually within 48 hours . v) How long should the antibiotics be given? Treatment duration depends on the bacteria, the patient and the organ involved . vi) How can resistance be avoided? Rotating between antibiotics has been proposed to reduce the emergence of multidrug resistant bacteria, although this concept remains to be validated by controlled studies.

Eur J Pediatr, 1999 Jan, 158(1), 67 - 70
Necrotising enterocolitis: is there a relationship to specific pathogens?
Peter CS, Feuerhahn M, Bohnhorst B, Schlaud M, Ziesing S, von der Hardt H, Poets CF.
Outbreaks of necrotising enterocolitis (NEC) have often been related to specific pathogens such as Enterobacteriaceae . This relationship, however, remains uncertain because of the retrospective nature of the studies addressing this issue . We performed a prospective study to investigate whether there is indeed an association between NEC and specific pathogens . Between April 1993 and March 1997, stools of neonates of < 36 weeks admitted to our neonatal unit were investigated for bacteria in weekly intervals . Clinical and bacteriological data from each infant who developed NEC were compared with those from two control infants matched for gestational age and date of admission . Eighteen infants developed 19 episodes of NEC (clinical signs + air in portal vein); 8 of these had laparotomy; two died . Occurrences of NEC were homogeneously distributed over the 4-year study period . The only significant differences in the clinical course prior to NEC were a more severe stage of respiratory distress syndrome {median 2 (0-4) vs . 0 (0-3), P < 0.05} and a higher proportion of infants who had only been formula fed (63 vs . 32%, P < 0.05) in the cases . Within the last week prior to NEC, potentially pathogenic bacteria were identified in stools of all cases and 79% of controls (P < 0.05) . However, there was no significant difference in the occurrence of specific pathogens or groups of pathogens in cases compared with controls . CONCLUSION: Although gut colonisation with potential pathogens appeared to be a prerequisite for the development of NEC, there were no specific bacteria associated with this disease if data from infants with NEC were compared with those from time- and gestational age-matched controls.

Zh Mikrobiol Epidemiol Immunobiol, 1998 Nov-Dec, (6), 8 - 11
{Experimental evaluation of the antibacterial activity of tomato pulp oil extract}; Vorob'ev AA et al.; The antibacterial action of the oil extract obtained from tomato pulp has been studied with the use of museum strains Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 5638-P and Candida albicans ATCC 885-653, recommended for the determination of the antibacterial activity of medicinal preparations (State Pharmacopoeia, edition XI), as well as Enterobacter, Streptococcus, Staphylococcus, Klebsiella and Escherichia clinical strains . As revealed in this study, tomato pulp oil extract produces a wide-spectrum antibacterial effect on Gram-positive and Gram-negative microorganisms and on fungi of the genus Candida . The study has determined that this antibacterial action is linked with the presence of a complex of organic acids (succinic, citric, tartaric, etc.).

Diagn Microbiol Infect Dis, 1998 Dec, 32(4), 281 - 7
Multicenter survey of the in vitro activity of four expanded-spectrum beta-lactams against consecutive contemporary clinical isolates; Fuchs PC et al.; A survey of the in vitro susceptibility of consecutive clinical bacterial isolates to cefotaxime, ceftazidime, cefpodoxime, and aztreonam was conducted at 10 North American medical centers during the first quarter of 1997 . All four drugs had good activity against Enterobacteriaceae and fastidious Gram-negative bacteria and poor activity against enterococci and methicillin-resistant staphylococci . No significant trends in susceptibility to cefotaxime or ceftazidime were observed when compared with a previous similar survey . The use of cefpodoxime MIC > 2.0 micrograms/mL as a marker for extended-spectrum beta-lactamase production by Escherichia coli and Klebsiella spp . had good sensitivity, but the specificity was very poor for E . coli . Thus, at least for E . coli, this screening test seems to be of questionable value unless used to indicate the need for additional tests such as clavulanic acid inhibition . Disk diffusion zone diameters correlated well with the MICs for all four drugs and support the current interpretive criteria.

Intern Med, 1998 Dec, 37(12), 1014 - 8
Changes in the incidence and etiological patterns of bacteremia associated with acute leukemia over a 25-year period; Funada H et al.; During the 25-year period from 1972-1996, 360 episodes of bacteremia occurred in 248 (45%) of a total of 548 patients with acute leukemia on our hematology ward, with the rate of occurrence remaining almost unchanged . Patients with acute nonlymphocytic leukemia, however, had a significant decrease in the incidence of bacteremia during the last 5-year period . Gram-negative bacilli decreased in relative frequency from 64% for the first 15-year period to 40% for the last 5-year period, whereas gram-positive cocci increased from 24% to 51% . Escherichia coli and Enterobacter cloacae somewhat decreased in frequency, whereas coagulase-negative staphylococci and streptococci had considerable increases . In contrast, Pseudomonas aeruginosa was isolated at a relatively constant frequency, forming one of the top two pathogens throughout the study period . Despite the shift toward gram-positive cocci, therefore, P . aeruginosa remains a key organism in considering the initial empiric antibiotic regimen and infection prevention during neutropenia.

Biochemistry, 1999 Feb 2, 38(5), 1469 - 77
Beta-secondary and solvent deuterium kinetic isotope effects on catalysis by the Streptomyces R61 DD-peptidase: comparisons with a structurally similar class C beta-lactamase; Adediran SA et al.; Beta-secondary and solvent deuterium kinetic isotope effects have been determined for the steady-state kinetic parameters V/K and V for turnover of a series of acyclic substrates by the DD-peptidase of Streptomyces R61 and the class C beta-lactamase of Enterobacter cloacae P99 . Although these enzymes are evolutionarily related and have very similar tertiary and active site structure, they are functionally very different-the former efficiently catalyzes the hydrolysis of beta-lactams but not acyclic peptides while vice versa applies to the latter . The measured kinetic isotope effects reveal both similarities and differences in the steady-state transition states for turnover of the various substrates by these enzymes . In most cases, inverse beta-secondary isotope effects were observed, reflecting typical acyl-transfer transition states . With one substrate, however, m-{{(phenylacetyl)glycyl}oxy}benzoic acid, isotope effects on V/K of very close to unity were obtained for both enzymes . These were interpreted in terms of acylation transition state conformations where the extent of beta-CH hyperconjugation was similar to that in the free substrate . Differences in deacylation transition states (V) between the two enzymes with this substrate were interpreted in terms of different acyl-enzyme conformations . Solvent deuterium kinetic isotope effects on V/K were uniformly small, some even inverse, for both enzymes and with all substrates tested . At face value, this suggests the counterintuitive conclusion that little proton transfer occurs in acylation transition states in all of these instances . Closer analysis, however, suggests that for ester and amide (and probably beta-lactam) substrates, this result probably arises from an increase in proton fractionation factors on substrate binding being offset by their decrease in the acylation transition state . The former event derives from proton rearrangement on substrate binding and the latter, presumably, from general acid/base catalysis . This result may be general to all beta-lactam-recognizing enzymes . The solvent isotope effects also suggest that, at least for the P99 beta-lactamase, the acylation transition state of a thioester substrate does not involve proton transfer . This can be interpreted in terms of the rate-determining breakdown of a tetrahedral intermediate where no protonation of the leaving thiolate is required . Deacylation transition states of both enzymes appear to involve significant proton transfer, presumably arising from general acid/base catalysis.

Microb Ecol, 1999 Feb, 37(2), 129 - 139
Comparison of Parental and Transgenic Alfalfa Rhizosphere Bacterial Communities Using Biolog GN Metabolic Fingerprinting and Enterobacterial Repetitive Intergenic Consensus Sequence-PCR (ERIC-PCR); Di Giovanni GD et al.; > Abstract Rhizosphere bacterial communities of parental and two transgenic alfalfa (Medicago sativa L.) of isogenic background were compared based on metabolic fingerprinting using Biolog GN microplates and DNA fingerprinting of bacterial communities present in Biolog GN substrate wells by enterobacterial repetitive intergenic consensus sequence-PCR (ERIC-PCR) . The two transgenic alfalfa expressed either bacterial (Bacillus licheniformis) genes for alpha-amylase or fungal (Phanerochaete chrysosporium) genes for Mn-dependent lignin peroxidase (Austin S, Bingham ET, Matthews DE, Shahan MN, Will J, Burgess RR, Euphytica 85:381-393) . Cluster analysis and principal components analysis (PCA) of the Biolog GN metabolic fingerprints indicated consistent differences in substrate utilization between the parental and lignin peroxidase transgenic alfalfa rhizosphere bacterial communities . Cluster analysis of ERIC-PCR fingerprints of the bacterial communities in Biolog GN substrate wells revealed consistent differences in the types of bacteria (substrate-specific populations) enriched from the rhizospheres of each alfalfa genotype . Comparison of ERIC-PCR fingerprints of bacterial strains obtained from substrate wells to substrate community ERIC-PCR fingerprints suggested that a limited number of populations were responsible for substrate oxidation in these wells . Results of this study suggest that transgenic plant genotype may affect rhizosphere microorganisms and that the methodology used in this study may prove a useful approach for the comparison of bacterial communities.

J Mol Evol, 1999 Feb, 48(2), 142 - 50
Physical and genetic map of the genome of Buchnera, the primary endosymbiont of the pea aphid Acyrthosiphon pisum; Charles H et al.; The genome of Buchnera, an endosymbiotic bacterium of the pea aphid Acyrthosiphon pisum, was characterized by pulse-field gel electrophoresis (PFGE) as a circular DNA molecule of 657 kb . The enzymes I-CeuI, CpoI, ApaI, SmaI, NaeI, SacII, MluI, FspI, and NruI were used to cleave the DNA of Buchnera into fragments of suitable size for PFGE analysis . A physical map of the Buchnera genome, including restriction fragments from seven of these enzymes, was constructed using double cutting, partial digestion, and hybridization with linking fragments, and 29 genes and operons were localized on the map . In addition, the genomic map of Buchnera was compared with those of Escherichia coli and Haemophilus influenzae . The gene order in Buchnera is more similar to that of E . coli than to H . influenzae . The dramatic shrinkage of the Buchnera genome compared with those of other members of the closely related Enterobacteriaceae family is discussed in terms of evolution under the influence of the intracellular symbiotic association.

Infect Control Hosp Epidemiol, 1999 Jan, 20(1), 37 - 42
Prevalence and risk factors for nosocomial infections in four university hospitals in Switzerland; Pittet D et al.; OBJECTIVE: To determine the prevalence and risk factors for nosocomial infections (NIs) in four Swiss university hospitals . DESIGN AND SETTING: A 1-week period-prevalence survey conducted in May 1996 in medical, surgical, and intensive-care wards of four Swiss university hospitals (900-1,500 beds) . Centers for Disease Control and Prevention definitions were used, except that asymptomatic bacteriuria was not categorized as NI . Study variables included patient demographics, primary diagnosis, comorbidities, exposure to medical and surgical risk factors, and use of antimicrobials . Risk factors for NIs were determined using logistic regression with adjustment for length of hospital stay, study center, device use, and patients' comorbidities . RESULTS: 176 NI were recorded in 156 of 1,349 screened patients (11.6%; interhospital range, 9.8%-13.5%) . The most frequent NI was surgical-site infection (53; 30%), followed by urinary tract infection (39; 22%), lower respiratory tract infection (27; 15%), and bloodstream infection (23; 13%) . Prevalence of NI was higher in critical-care units (25%) than in medical (9%) and surgical wards (12%) . Overall, 65% of NIs were culture-proven; the leading pathogens were Enterobacteriaceae (44; 28%), Staphylococcus aureus (20; 13%), Pseudomonas aeruginosa (17; 11%), and Candida species (16; 10%) . Independent risk factors for NI were central venous catheter (CVC) use (odds ratio {OR}, 3.35; 95% confidence interval {CI95}, 2.91-3.80), admission to intensive care (OR, 1.75; CI95, 1.30-2.21), emergency admission (OR, 1.57; CI95, 1.15-2.00), impaired functional status (Karnofsky index 1-4: OR, 2.56; CI95, 1.953.17), and McCabe classification of ultimately fatal (OR, 2.50; CI95, 2.04-2.96) or rapidly fatal (OR, 2.25; CI95, 1.52-2.98) underlying condition . CONCLUSIONS: According to the results of this survey, NIs are frequent in Swiss university hospitals . This investigation confirms the importance of CVCs as a major risk factor for NI . Patient comorbidities must be taken into account to adjust for case mix in any study comparing interhospital or intrahospital infection rates.

Appl Environ Microbiol, 1999 Feb, 65(2), 862 - 4
Exopolysaccharide-producing bacteria from sugar beets; Tallgren AH et al.; Six hundred microorganisms were isolated from sugar beets collected from different parts of Finland to study their slime production . A total of 170 of them produced exopolysaccharides, of which 35% were heteropolysaccharides . The yield of heteropolysaccharides from sucrose was lower than that of dextrans . Five isolates, which were chosen for closer study, were identified as Leuconostoc mesenteroides (two species), Rahnella aquatilis (two species), and Enterobacter amnigenus.

Appl Environ Microbiol, 1999 Feb, 65(2), 698 - 706
Chemical and sensory changes associated with microbial flora of Mediterranean boque (Boops boops) stored aerobically at 0, 3, 7, and 10 degreesC; Koutsoumanis K et al.; The development of a microbial population and changes in the physicochemical and sensorial characteristics of Mediterranean boque (Boops boops), called gopa in Greece, stored aerobically at 0, 3, 7, and 10 degreesC were studied . Pseudomonads and Shewanella putrefaciens were the dominant bacteria at the end of the storage period, regardless of the temperature tested . Enterobacteria and Brochothrix thermosphacta also grew, but their population density was always 2 to 3 log10 CFU g-1 less than that of pseudomonads . The concentration of potential indicators of spoilage, glucose and lactic acid, decreased while that of the alpha-amino groups increased during storage . The concentrations of these carbon sources also decreased on sterile fish blocks inoculated with strains isolated from fish microbial flora . The organic acid profile of sterile fish blocks inoculated with the above-mentioned bacteria and that of naturally spoiled fish differed significantly . An excellent correlation (r = -0.96) between log10 counts of S . putrefaciens or Pseudomonas bacteria with freshness was observed in this study.

Int J Food Microbiol, 1998 Dec 8, 45(2), 135 - 42
The spoilage flora of vacuum-packaged, sodium nitrite or potassium nitrate treated, cold-smoked rainbow trout stored at 4 degrees C or 8 degrees C; Lyhs U et al.; The spoilage flora of vacuum-packaged, salted, cold-smoked rainbow trout fillets, with or without the addition of nitrate or nitrite, stored at 4 degrees C and 8 degrees C, was studied . Of 620 isolates, lactic acid bacteria were the major fraction (76%), predominating in all samples of spoiled product . However, the phenotypical tests used were insufficient to identify the lactic acid bacteria to the species level . Gram-positive, catalase-positive cocci, gram-negative, oxidase-negative rods and gram-negative, oxidase-positive rods were found in 6%, 16% and 2% of the samples, respectively . Of 39 gram-positive, catalase-positive cocci, 29 were identified as staphylococci and 10 as micrococci . Eighty-five isolates were found to belong to the family Enterobacteriaceae, with 45 of those being Serratia plymuthica . Eleven isolates from the nitrate treated samples stored at 8 degrees C were identified as Pseudomonas aeruginosa . The occurrence of P . aeruginosa and staphylococci in the nitrate-containing samples, stored at 8 degrees C, may cause problems with respect to the safety of the product . The types of lactic acid and other bacteria in the spoilage flora were generally reduced by the addition of nitrate or nitrite to fillets.

Ann Trop Paediatr, 1998 Dec, 18(4), 279 - 83
Neonatal meningitis in Addis Ababa: a 10-year review; Gebremariam A; In a hospital population-based retrospective study of neonatal meningitis, 55 cases were identified over a period of 10 years . The prevalences of meningitis for preterm and term newborns were 3.66 and 0.97 per 1000, respectively (22/6465 vs 33/36638; p < 0.01) . The overall prevalence was 1.37 per 1000 live births . Twenty-two (40%) babies with meningitis died, more preterm than term (13/22 vs 9/33; p < 0.05) . Known maternal risk factors for neonatal meningitis were observed in 15 (27%) babies . The risk factors were more common in preterm than in term newborns (10/22 vs 5/33; p < 0.05) . The common causative organisms were Klebsiella pneumoniae, Escherichia coli and Enterobacter spp . which together accounted for 67% of all CSF isolates . These organisms were evenly distributed between early- and late-onset meningitis, and among term and preterm newborns . Seven of 33 (21%) of the surviving newborns developed neurological complications . The short-term sequelae were hydrocephalus, spastic paresis and seizures.

Int J Food Microbiol, 1998 Nov 24, 45(1), 43 - 53
Update on media for isolation of Enterobacteriaceae from foods; de Boer E; Testing for 'total' Enterobacteriaceae, coliforms and Escherichia coli as marker organisms in foods and detection of specific pathogens of the family Enterobacteriaceae, including pathogenic E . coli, Salmonella, Shigella and Yersinia spp . is widely applied in many food control laboratories . This review describes some recent developments in culture media for these organisms . Methods for enumeration of E . coli include the standard MPN technique, a membrane-filter method and the use of media containing chromogenic and fluorogenic indicators for beta-D-glucuronidase (GUD) activity . Shiga toxin-producing E . coli O157 strains usually do not ferment sorbitol and are GUD-negative . These characteristics are used in selective media for these organisms, such as cefixime tellurite sorbitol MacConkey agar . For the detection of salmonellae, motility enrichment in Modified Semisolid Rappaport-Vassiliadis (MSRV) medium shows equal or better results than the use of standard Rappaport-Vassiliadis broth . Addition of nitrofurantoin to diagnostic semisolid salmonella agar and to xylose lysine desoxycholate agar favours the isolation of S . enteritidis . Recently developed salmonella media use different selective and diagnostic properties, such as acid formation from propylene glycol, glucuronate fermentation, fermentation of glycerol and addition of Tergitol 4 as selective agent . The isolation of Shigella spp . from foods is rather difficult and further evaluation of suggested isolation systems and the development of more effective methods for the isolation of this pathogen are needed . Yersinia enterocolitica includes both pathogenic and nonpathogenic biotypes and serogroups . As no single procedure will recover all pathogenic strains of Y . enterocolitica, the use of two isolation procedures in parallel is recommended.

Mem Inst Oswaldo Cruz, 1998 Nov-Dec, 93(6), 823 - 6
Haemolymph and fat body metallo-protease associated with Enterobacter cloacae infection in the bloodsucking insect, Rhodnius prolixus; Feder D et al.; Analysis of zymograms with SDS-polyacrilamide gel electrophoresis containing gelatin as substrate, and performed on samples of haemolymph or fat body taken from Rhodnius prolixus inoculated or not with Enterobacter cloacae, demonstrated distinct patterns of protease activities: (i) in the haemolymph two proteases were induced in insects inoculated with bacteria; (ii) two proteases were detected in the fat bodies derived from non-inoculated controls or insect inoculated with sterile culture medium; (iii) haemolymph and fat body had both the same apparent molecular weights proteases (46 and 56 kDa); and (iv) these enzymes were characterized as metallo-proteases . The association of these enzymes in Rhodnius infected with bacteria was discussed.

J Biol Chem, 1999 Feb 5, 274(6), 3300 - 7
Identification of an RcsA/RcsB recognition motif in the promoters of exopolysaccharide biosynthetic operons from Erwinia amylovora and Pantoea stewartii subspecies stewartii; Wehland M et al.; The regulation of capsule synthesis (Rcs) regulatory network is responsible for the induction of exopolysaccharide biosynthesis in many enterobacterial species . We have previously shown that two transcriptional regulators, RcsA and RcsB, do bind as a heterodimer to the promoter of amsG, the first reading frame in the operon for amylovoran biosynthesis in the plant pathogenic bacterium Erwinia amylovora . We now identified a 23-base pair fragment from position -555 to -533 upstream of the translational start site of amsG as sufficient for the specific binding of the Rcs proteins . In addition, we could detect an RcsA/RcsB-binding site in a corresponding region of the promoter of cpsA, the homologous counterpart to the E . amylovora amsG gene in the operon for stewartan biosynthesis of Pantoea stewartii . The specificity and characteristic parameters of the protein-DNA interaction were analyzed by DNA retardation, protein-DNA cross-linking, and directed mutagenesis . The central core motif TRVGAAWAWTSYG of the amsG promoter was found to be most important for the specific interaction with RcsA/RcsB, as evaluated by mutational analysis and an in vitro selection approach . The wild type P . stewartii Rcs binding motif is degenerated in two positions and an up-mutation according to our consensus motif resulted in about a 5-fold increased affinity of the RcsA/RcsB proteins.

J Med Microbiol, 1999 Jan, 48(1), 73 - 7
Analysis of mutations to gyrA in quinolone-resistant clinical isolates of Enterobacter cloacae; Dekitsch C et al.; The gyrA subgenes of a quinolone-resistant Enterobacter cloacae clinical isolate (ofloxacin MIC, 16 mg/L) and of a control, E . cloacae NCTC 10005 (ofloxacin MIC, 0.03 mg/L), were amplified by polymerase chain reaction (PCR) and sequenced . The resistant isolate had mutations at the codons for amino acids 83, 89 and 90 . The first of these mutations led to replacement of serine-83 by tyrosine, whereas the other mutations were silent . Digestion of PCR-amplified DNA fragments with the restriction enzyme HinfI detected mutations at the same site in gyrA in six further quinolone resistant E . cloacae isolates.

J Med Microbiol, 1999 Jan, 48(1), 67 - 71
Antibiotic resistance patterns among blood culture isolates in a Danish county 1981-1995; Kristensen B et al.; All episodes of bacteraemia during a 15-year period (1981-1995) in the County of Northern Jutland, Denmark, were analysed with regard to antibiotic resistance . A total of 8840 isolates from 7938 episodes of bacteraemia was identified . Over time, no changes in bacterial aetiology were noted . Three isolates of Staphylococcus aureus were methicillin resistant (0.2%) and six were gentamicin resistant (0.4%) . Among coagulase-negative staphylococci a 14% increase in resistance to penicillin was observed (95% confidence intervals, CI: 2-26%) . Likewise, the frequency of resistance to methicillin, gentamicin and erythromycin increased, the corresponding figures being 38% (CI: 26-50%), 26% (CI: 14-38%) and 32% (CI: 16-50%), respectively, whereas a 14% decrease in resistance to streptomycin was recorded (CI: 4-24%) . A 20% (CI: 2-37%) increase of coagulase-negative staphylococci resistant to three or more antibiotics was observed . The frequency of ampicillin resistance increased by 9% among Escherichia coli (CI: 4-13%) and by 10% (CI: 6-14%) in all Enterobacteriaceae . Among Enterobacteriaceae the level of resistance to third-generation cephalosporins, carbapenems, aminoglycosides and fluoroquinolones remained low (<1%) . The frequency of resistance to three or more antibiotics remained fairly stable among Enterobacteriaceae, although a slight increase was noted among E . coli (5%; CI: 0-10%) The recommended regimen for empirical antibiotic treatment in this region (a combination of penicillin G or ampicillin and an aminoglycoside) provided an overall coverage of 94% (CI: 94-95%), although a slight decrease was noted at the end of the period . In conclusion, acquired antibiotic resistance was maintained at a low level compared with most other European countries and regions during the 15-year period studied.

Cent Eur J Public Health, 1998 Nov, 6(4), 296 - 9
Qualitative identification of volatile metabolites from two fungi and three bacteria species cultivated on two media; Kiviranta H et al.; Two fungal species, Aspergillus fumigatus and Penicillium brevicompactum and three bacteria, Klebsiella pneumoniae, Enterobacter agglomerans and Streptomyces albus were cultivated on two media, malt extract agar and dichloran glycerol agar . The volatile metabolite samples from the cultures were adsorbed on Tenax TA and analyzed qualitatively by thermal desorption gas chromatography and with a mass selective detector . Various hydrocarbons, alcohols, ketones, esters and terpenes were identified . The production was highly dependent on both the medium and the microbial species . 2-Methyl-1-propanol, 2-methyl-1-butanol and 3-methyl-1-butanol were the most commonly produced substances . The bacterial species did not produce any hydrocarbons that were characteristic to the fungi (e.g . methyl-1,3-pentadiene, 1-octene and 1,3-octadiene or 8-carbon alcohols 1-octen-3-ol and 3-octanol) . Instead, K . pneumoniae and E . agglomerans produced 3-hydroxy-2-butanone and 1-hydroxy-2-propanone, which were not produced by the fungi . Geosmin and a large number of sesquiterpenes were produced by S . albus.

Zentralbl Hyg Umweltmed, 1998 Dec, 201(4-5), 387 - 403
{Emissions and immisions of bio-aerosols from a duck fattening unit}; Seedorf J et al.; In a field study emissions and immissions (receptor exposition) of bioaerosols emitted from and near a duck fattening house (25 m distance) were investigated . Within the livestock building mean concentrations of 3,342,289 CFU m-3 for airborne total mesophilic bacteria were determined . Total dust and endotoxin yields were 1.9 mg m-3 and 7,132.4 ng m-3, respectively . Additionally, enterobacteria, mesophilic and thermotolerante fungi as well as mesophilic actinomycetes were detectable . Measurements of immissions have shown, that downwind in the rear of the house a mean total germ concentration of 10,007 CFU m-3 was measurable in contrast to the upwind side of the building, where no airborne mesophilic bacteria were found . Higher concentrations downwind were generally determined for total dust, mesophilic fungi and actinomycetes, too, but not so for endotoxins . A supporting application of a numeric dispersion model confirmed the immissions for total mesophilic bacteria near by the duck fattening house . From this viewpoint immission predictions can be made in future for varying input data, i.e . wind conditions, of different components of bioaerosols.

Curr Opin Rheumatol, 1999 Jan, 11(1), 68 - 74
Rheumatologic manifestations of gastrointestinal disorders; Braun J et al.; There are many different rheumatic symptoms of gastrointestinal (GI) disorders and a whole range of GI symptoms that occur in rheumatologic disorders . Spondyloarthropathies (SpA) are closely related to the GI tract . Bacterial DNA has been detected in peripheral but not the sacroiliac joints of patients, including enterobacteria; the significance of this finding is not clear yet because antibiotic therapy seems not to be effective . The synovial lymphocyte proliferation of reactive arthritis (ReA) patients to the 60-kD heat-shock protein of Yersinia plays a major role in the immune response . Anti-Klebsiella antibodies are associated with gut lesions in SpA; their significance for the pathogenesis of SpA remains uncertain . ReA patients seem to have an impaired TH1-cytokine response, which might contribute to disease persistence . HLA B27-positive subjects seem to have a low tumor necrosis factor-alpha secretor status, possibly leading to diminished immune responses against certain microbes . In patients with Whipple's disease, Tropheryma whippelii can be cultured from gut biopsy specimens when interleukin-4 is added . The gene for hemochromatosis has been identified . Hepatitis C virus DNA can be found in many patients with cryoglobulinemia . Treatment with interferon-alpha might help in some patients . Effective treatment for primary biliary cirrhosis with ursodeoxycholic acid is not helpful for rheumatic symptoms . The severity of esophageal dysfunction in systemic sclerosis does not correlate with symptoms . GI symptoms do, although not frequently, occur in vasculitides.

J Chromatogr B Biomed Sci Appl, 1998 Dec 11, 720(1-2), 59 - 64
Assay of nicotinamide deamidase activity using high-performance liquid chromatography; Oishi M et al.; A rapid, simple and reproducible method has been developed for the determination of nicotinamide deamidase activity using high-performance liquid chromatography (HPLC) . Nicotinic acid (NA) liberated from nicotinamide (NAA) after a 15-min enzyme reaction was determined directly by HPLC without further separation steps . Both NA, the product, and NAA, the substrate were separated by reversed-phase ion-pair isocratic chromatography and detected at 261 nm . The present method could be applied to the measurement of deamidase activity in crude cell extracts prepared from several bacterial strains . The Michaelis constant of nicotinamide deamidase in Enterobacter agglomerans was 36 microM for NAA . This method is useful for the measurement of nicotinamide deamidase from various sources.

Rheum Dis Clin North Am, 1998 Nov, 24(4), 883 - 94, xi-xii
Animal models of human leukocyte antigen B27-linked arthritides; Khare SD et al.; The major histocompatibility complex class I allele human leukocyte antigen (HLA) B27 is strongly associated with human spondyloarthropathies . To date, 12 subtypes of HLA-B27 are known and most of them are linked with human spondyloarthropathies in different ethnic populations . Although these subtypes differ from each other by a few amino acids, the have an identical B pocket in the base of the antigen-binding groove . Considering the structure of HLA-B27 subtypes and their peptide binding specificity, it is important to consider their role as antigen-presenting molecules . Many B27-linked diseases begin after an infection with an enterobacteria, suggesting a role for environmental antigens in addition to an HLA-B27 molecule . To delineate the role of infection, studies have been carried out in animal models of reactive arthritidis . More recently, transgenic animal models have been used to understand the handling of environmental antigens by HLA-B27 molecule . This article discusses some of these transgenic and nontransgenic animal models of human diseases.

Gene, 1999 Jan 8, 226(1), 35 - 40
Molecular organization of the xcp gene cluster in Pseudomonas putida: absence of an xcpX (gspK) homologue; de Groot A et al.; A DNA fragment containing xcp (gsp) gene homologues, required for extracellular protein secretion by the general secretory pathway (GSP) in various Gram-negative bacteria, was cloned from Pseudomonas putida (Pp) strain WCS358 and sequenced . The results presented here and those previously reported (de Groot, A., Krijger, J.-J., Filloux, A., Tommassen, J., 1996 . Characterization of type II protein secretion (xcp) genes in the plant growth-stimulating Pseudomonas putida, strain WCS358 Mol . Gen . Genet . 250, 491-504) complete the sequence of the xcp gene cluster of Pp . Unlike that of Pseudomonas aeruginosa (Pa), the xcp gene cluster of Pp contains a gspN homologue . More surprisingly, in contrast to all known gsp gene clusters, the xcpX (gspK) homologue is not found . In addition, genes flanking the xcp cluster of Pp are not related to those flanking the xcp genes of Pa . Overall, the xcp gene products of Pp are as much related to those of Pa as to gsp gene products of enterobacterial species, suggesting that the xcp clusters of Pp and Pa have evolved separately.

J Bacteriol, 1999 Jan, 181(2), 593 - 9
Motility of Helicobacter pylori is coordinately regulated by the transcriptional activator FlgR, an NtrC homolog; Spohn G et al.; sigma54 is the subunit of bacterial RNA polymerase that transcribes from promoters with enhancer elements bound by enhancer-binding proteins . By computer searches of Helicobacter pylori genomic sequences, chromosomal gene disruption, and RNA analyses, we have identified sigma54-recognized promoters that regulate transcription of flagellar basal body and hook genes, as well as the enhancer-binding protein FlgR (flagellum regulator), a transactivating protein of the NtrC family . We demonstrate that FlgR is required for bacterial motility and transcription of five promoters for seven basal body and hook genes . In addition, FlgR acts as a repressor of transcription of the sigma28-regulated flaA flagellin gene promoter, while changes in DNA topology repress transcription of the sigma54-regulated flaB flagellin gene promoter . Our data indicate that regulation of flagellar gene expression in H . pylori shows similarities with that in enterobacteriaceae and Caulobacter.

J Med Microbiol, 1998 Jun, 47(6), 499 - 504
A cluster of cases of infections due to Aeromonas hydrophila revealed by combined RAPD and ERIC-PCR; Davin-Regli A et al.; Two polymerase chain reaction (PCR)-based methods were used for epidemiological typing of Aeromonas hydrophila . Random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) were applied to an outbreak involving seven patients . The epidemiological situation appeared complex; with the exception of two clinical isolates, all gave unique patterns with both techniques . These methods demonstrated nosocomial transmission in one unit and permitted the study to exclude a common environmental source in the hospital . The coincidental clustering of patients infected with A . hydrophila probably resulted from an increased prevalence of aeromonads in waters during summer, although no single RAPD or ERIC-PCR pattern was found among both clinical and environmental samples . RAPD and ERIC-PCR proved to be effective for the epidemiological study of A . hydrophila strains.

J Food Prot, 1998 Dec, 61(12), 1644 - 8
Postprocess contamination of flexible pouches challenged by in situ immersion biotest; Song YS et al.; Packages were evaluated for leaks by determining microbial penetration through microchannels as a function of test organism concentration, location in a retort, and microchannel diameter and length . A flexible pouch was used in an in situ immersion biotest coupled with a state-of-the-art retort . Microchannel diameters of 10 to 661 microm with 3- and 6-mm lengths were created by placing tungsten wires in vacuum heat-sealed flexible pouches . After removing the wires, these pouches were subsequently heat processed under pressure . They were then biotested in cooling water containing 10(3) and 10(6) CFU of motile Enterobacter aerogenes per ml for 30 min and were dried immediately after manual unloading . After incubation at 37 degrees C for 3 days, they were visually examined for contamination . The high-temperature retorting process was shown to decrease microchannel diameters by an average of 20% . Generally, the smaller the microchannel diameter, the greater the percent shrinkage . Statistical analysis of the biotesting data showed that microchannel diameter and length had strong effects on microbial penetration (P < 0.01) . Microbial concentration had a borderline significant effect (P < 0.05), but the effect of package location in the retort was not significant . At conservative conditions, such as a 3-mm microchannel length and a cooling water contamination level of 10(6) CFU/ml, the selected microorganism can penetrate microchannels with diameters as small as 7 microm . However, the minimum microchannel diameter for penetration could be as large as 46 microm at practical conditions of 6-mm microchannel length and contamination levels of 10(3) CFU/ml.

J Food Prot, 1998 Dec, 61(12), 1623 - 8
Prevalence and genetic variability of Arcobacter species in mechanically separated turkey; Manke TR et al.; A survey for Arcobacter spp . and Arcobacter butzleri in mechanically separated turkey was conducted during the winter of 1995 and summer and fall of 1996 . Arcobacter spp . and A . butzleri were identified by polymerase chain reaction and species-specific oligonucleotide probes . Arcobacter spp . were isolated from 77% (303 out of 395) of the mechanically separated turkey samples with 74% (223 out of 303) of these samples positive for A . butzleri . Of the 121 A . butzleri isolates tested, 86 different patterns were evident following amplification of enterobacterial repetitive intergenic consensus sequences . The extent of genetic polymorphism indicated multiple sources of contamination.

Acta Microbiol Immunol Hung, 1998, 45(3-4), 433 - 46
Investigation of the presence of different broad-spectrum beta-lactamases among clinical isolates of Enterobacteriacae; Nagy E et al.; Chromosomal or plasmid-encoded beta-lactamases are the most frequent causes of resistance to broad-spectrum beta-lactam antibiotics in clinical isolates of Gram-negative bacteria . Different screening methods can be used for their detection during routine laboratory work, while molecular biological methods may help in the detection of the genetic background of the phenotypic resistance . Clinical isolates of Klebsiella pneumoniae (170) and Enterobacter cloaceae (82) were obtained from different parts of Hungary, whereas those of Serratia marcescens (15) were isolated in our Department from a nosocomial outbreak . Disk diffusion and the Etest were used to screen inducible Class C beta-lactamase and plasmid-mediated extended spectrum beta-lactamases (ESBLs) among clinical isolates of Enterobacteriaceae . Single-strand conformation polymorphism (SSCP) analysis of the PCR products obtained after using SHV-specific primers revealed the presence of SHV-2 and SHV-5 ESBL among 170 K . pneumoniae strains in 12 and 3 cases, respectively . The results of the screening methods and the PCR-SSCP analysis suggested that 14 of the 15 S . marcescens strains not only produced the Class C, inducible chromosomal beta-lactamase, but also acquired a plasmid-mediated SHV-2-type ESBL . One strain isolated from the environment during the outbreak was genetically related to the other isolates, as demonstrated by the different typing methods, but it did not produce ESBL . The in vivo transfer of SHV-2 gene was assumed from an SHV-2 positive K . pneumoniae strain present in the same ward, in the same patient and at the same time . A very high prevalence of the stable derepressed mutants of E . cloaceae was confirmed among the Hungarian isolates . Seventy seven per cent of the strains produced high amounts of beta-lactamase without induction being responsible for their resistance to third-generation cephalosporins . Nineteen per cent of the strains were inducible when cefoxitin or imipenem was used, as confirmed by direct measurement of the MICs with the Etest.

Acta Microbiol Immunol Hung, 1998, 45(3-4), 341 - 8
Potential role of microbiological agents in sudden infant death syndrome; Csukas Z et al.; The potential role of microbiological agents was investigated in 10 cases of Sudden Infant Death Syndrome in Budapest between September 1996 and December 1997 . Autopsy, histological examination and microbiological tests were performed on samples of blood, cerebrospinal fluid, pharyngeal and bronchial samples from infants under six months died suddenly, without previous diseases . The multifactorial pathomechanism of SIDS was suggested by detection of Parainfluenza Type virus antigen, isolation of toxin producing Staphylococcus aureus, Enterobacteriaceae and Candida albicans strains in large number of more samples of the same infant.

Curr Med Chem, 1998 Dec, 5(6), 441 - 56
Beta-lactamase inhibitors: agents to overcome bacterial resistance; Maiti SN et al.; The extensive use of beta-lactam antibiotics in hospitals and community has created major resistance problems leading to increased morbidity, mortality and health-care costs . Resistance is most often mediated by -lactamases, which have emerged in both gram-positive and gram-negative bacteria . A novel approach to countering bacterial beta-lactamases is the delivery of a beta-lactam antibiotic in combination with a beta-lactamase inhibitor . Several such combinations are currently available, containing inhibitors clavulanic acid, sulbactam and tazobactam . These inhibitors are not, however, active against all beta-lactamases and the AmpC chromosomal enzymes that are hyperproduced by some enterobacteria and pseudomonas are a particular gap . Moreover, genes for these AmpC enzymes have begun to escape to plasmids . Consequently, there is a growing need for new broad-spectrum beta-lactamase inhibitors . This review offers an overview of synthetic beta-lactamase inhibitors, emphasizing information on their structures, and highlighting their activity against various beta-lactamases, particularly AmpC enzymes . Effective inhibition of AmpC enzymes are to be found among the penems and monobactams, but none of these has yet proved suitable for pharmaceutical development.

Ann Pharm Fr, 1998, 56(6), 244 - 9
{Enzymatic resistance to imipenem in gram-negative bacilli: NMC-A, an original carbapenemase}; Boyer-Mariotte S; Carbapenems such as imipenem are beta-lactam antibiotics usually stable to the hydrolytic activity of beta-lactamases . Nevertheless, resistance to imipenem by production of carbapenemases has been described in few species of Gram negative bacilli . This mechanism of resistance remains exceptional in Enterobacteriaceae . These carbapenemases are principally metallo-enzymes that possess a zinc ion in their active site . Enterobacter cloacae strain NOR-1, is resistant to imipenem by production of an inducible chromosomal beta-lactamase which is not a metallo-enzyme but an Ambler class A beta-lactamase . This enzyme displays a strong hydrolytic activity against carbapenems but also against cephamycins which has never been previously observed for beta-lactamases of this class . These properties suggest that NMC-A possesses an original tridimensional structure of its active site allowing hydrolysis of molecules generally protected by the configuration of their lateral chain . Crystallographic study of this enzyme will permit to understand its mechanism of action and serve the development of new beta-lactams stable to b-lactamase hydrolytic activity.

Arch Microbiol, 1998 Dec, 171(1), 1 - 5
The anaerobic degradation of L-serine and L-threonine in enterobacteria: networks of pathways and regulatory signals; Sawers G; The mechanisms controlling the biosynthesis and degradation of l-serine and l-threonine are remarkably complex . Their metabolism forms a network of pathways linking several amino acids, central primary metabolites such as pyruvate, oxaloacetate and 3-phosphoglycerate, and C1 metabolism . Studies on the degradation of these amino acids in Escherichia coli have revealed the involvement of fascinating enzymes that utilise quite diverse catalytic mechanisms . Moreover, it is emerging that both environmental and metabolic signals have a major impact in controlling enzyme synthesis This is exemplified by the anaerobically regulated tdc operon, which encodes a metabolic pathway for the degradation of serine and threonine . Studies on this pathway are beginning to provide insights into how an organism adapts its genetic makeup to meet the physiological demands of the cell.

J Biotechnol, 1998 Dec 11, 66(2-3), 211 - 7
Heterologous phi X174 gene E-expression in Ralstonia eutropha: E-mediated lysis is not restricted to gamma-subclass of proteobacteria; Schroll G et al.; E-lysis of Ralstonia eutropha H16, which belongs to the beta-subclass, was undertaken to verify whether transmembrane tunnel formation is possible in bacteria which do not belong to the enterobacteriaceae . For this purpose, a new gene E expression plasmid, pKG12, with two origins of replication, oriV and oriT, from plasmid pRP4, chloramphenicol and kanamycin resistance genes and a casette composed of lambda cI857 and lambda pR gene E was constructed . Temperature upshift of R . eutropha H16 (pKG12) from 28 to 45 degrees C during exponential growth resulted in lysis of the strain with features characteristic of E-mediated lysis of Escherichia coli . The cytoplasmic contents released can easily be separated from the still intact envelope fraction by centrifugation or filtration . As R . eutropha H16 represents an important industrial organism, E-mediated lysis could facilitate procedures for the recovery of intracellular mediators or products like polyhydroxyalkanoates.

Appl Microbiol Biotechnol, 1998 Nov, 50(5), 568 - 72
Isolation and characterization of Enterobacter cloacae capable of metabolizing asparagine; Nawaz MS et al.; A gram-negative, rod-shaped bacterium capable of utilizing L-asparagine as its sole source of carbon and nitrogen was isolated from soil and identified as Enterobacter cloacae . An intracellularly expressed L-asparaginase was detected and it deaminated L-asparagine to aspartic acid and ammonia . High-pressure liquid chromatography analysis of a cell-free asparaginase reaction mixture indicated that 2.8 mM L-asparagine was hydrolyzed to 2.2 and 2.8 mM aspartic acid and ammonia, respectively, within 20 min of incubation . High asparaginase activity was found in cells cultured on L-fructose, D-galactose, saccharose, or maltose, and in cells cultured on L-asparagine as the sole nitrogen source . The pH and temperature optimum of L-asparaginase was 8.5 and 37-42 degrees C, respectively . The half-life of the enzyme at 30 degrees C and 37 degrees C was 10 and 8 h, respectively.

J Pharmacol Exp Ther, 1998 Dec, 287(3), 854 - 9
Antitumor necrosis factor therapy in rat chronic granulomatous colitis: critical dose-timing effects on outcome; Videla S et al.; Inhibition of tumor necrosis fact (TNFalpha) is of potential benefit in the treatment of chronic inflammatory conditions . However, TNFalpha plays an important role in host defenses against infection, and blocking TNFalpha production may also have adverse effects . We tested the efficacy and safety of anti-TNFalpha therapy in experimental colitis induced by trinitrobenzenesulfonic acid . We cultured colonic wall specimens for bacterial growth and measured native TNFalpha protein synthesis in colonic tissue at days 0, 1, 4, 10 and 18 after induction of colitis . Anti-TNFalpha therapy (monoclonal g1 immunoglobulin, 15 mg/kg i.p., every third day) was started on either day 4 or day 10 after induction of colitis . On day 18, we measured the release of inflammatory mediators and scored colonic lesions . In acute lesions, several species of the common flora were grown, including Streptococcus, Staphylococcus, Bacteroides, clostridia and enterobacteria . In chronic lesions, only enterobacteria, clostridia and lactobacilli were isolated . TNFalpha production by inflamed colonic tissue was increased in both acute and chronic lesions . Anti-TNFalpha therapy induced a significant decrease in the release of inflammatory mediators and histopathological remission when treatment started on day 10 . However, anti-TNFalpha therapy increased eicosanoid release and lesion scores when treatment started on day 4 . In conclusion, acute colonic lesions showed polymicrobial infection . Anti-TNFalpha therapy induced remission of chronic intestinal inflammation, but early treatment did not prove effective.

Biochem Mol Biol Int, 1998 Dec, 46(5), 1027 - 41
A six-domain structural model for Escherichia coli translation initiation factor IF2 . Characterisation of twelve surface epitopes; Mortensen KK et al.; The Escherichia coli translation initiation factor IF2 is a 97 kDa protein which interacts with the initiator fMet-tRNAfMet, GTP and the ribosomal subunits during initiation of protein biosynthesis . For structural and functional investigations of the factor, we have raised and characterised monoclonal antibodies against E . coli IF2 . Twelve epitopes have been localised at the surface of the protein molecule by three different methods: Interactions of the monoclonal antibodies with nested deletion mutants of IF2, comparison of the relative location of the epitopes in a competition immunoassay and cross-reactivity analyses of the monoclonal antibodies towards IF2 from Salmonella typhimurium, Klebsiella oxytoca, Enterobacter cloacae, Proteus vulgaris, and Bacillus stearothermophilus . These data are combined with predicted secondary structure and discussed in relation to a six-domain structural model for IF2 . The model describes IF2 as a slightly elongated molecule with a structurally compact C-terminal domain, a well-conserved central GTP-binding domain, and a highly charged, solvent exposed N-terminal with protruding alpha-helical structures.

Mikrobiol Z, 1998 Jul-Aug, 60(4), 88 - 92
{The characteristics of the causative agents of suppurative-inflammatory complications in hemophiliacs}; Fedorovskaia EA et al.; Morphological-cultural and physiological-biochemical properties of 24 strains of microorganisms agents of pyo-inflammatory complications of different localization in patients with hemophilia have been studied . Microorganisms strains presented by the following species: Staphylococcus aureus, S . epidermidis, S . saprophyticus, Proteus vulgaris, P . morganii, Hafnia alvei, Serratia marcescens, have been identified . It was found out that in monoculture staphylococci prove to be the leading etiological agent (60.9%), gram-negative enterobacteria (52.2%) and bacterial associations (8.7%) occur more rarely . Special attention was paid to the study of resistance of antibiotics, circulation and pathogenicity factors that had a direct effect on the main disease severity . It was ascertained that high activity of enzymes and presence of pathogenicity factors were the peculiarities of microorganisms isolated from pyo-septic sites in patients with hemophilia . All the strains possessed multiple resistance to antibiotics.

Med Dosw Mikrobiol, 1998, 50(1-2), 77 - 87
{The role of rotaviruses in digestive tract infections of hospitalized children with diarrhoea at the Health Care Consortium in Sokoł Podlaski}; Nieminska-Gromada B et al.; The aim of the study was a trial of establishing of the frequency of rotavirus infection and mixed bacterial-viral infections in children treated for diarrhoea in a hospital in the period from July 1 1996 to June 30 1997 . Moreover, an attempt was made at establishing of the frequency of rotavirus colonization of the digestive tract in healthy newborns born in that hospital during the period of that study . The studies were done on feces samples from 169 children with diarrhoea from 4 days to 13 years, and from 30 healthy peers . In all samples rotaviruses were sought along with pathogenic Enterobacteriaceae Tests for rotaviruses were done with Slidex-Rota Kit 2 (Bio-Merieux) and for EPEC with the EPEC latex test (Biomex) . In all, rotaviruses were found in 88 ill children (52.1%) including mixed bacterial-viral infections in 10 (5.1%) children . In 9 children beside rotaviruses enteropathogenic E . coli (EPEC) were disclosed, and in 1 child S . enteritidis . Moreover, in 1 child (0.6%) culture yielded simultaneously S . sonnei and E . coli 0127 . No rotaviruses were found in any 30 healthy newborns, but from one of them E . coli 018 was cultured . The second most frequent aetiological factor in diarrhoea were EPEC organisms found in 17 (10.0%) children, the third factor were S . enteritidis strains in 6 children (3.6%) . In one case S . sonnei and E . coli 0127 were obtained from faces . Rotavirus infection was most frequent in children aged from 2 months to 3 years, and EPEC infection in children up to 2 years . The incidence was highest in winter/spring, with peak in April when 27 cases of rotavirus diarrhoea were noted.

Med Dosw Mikrobiol, 1998, 50(1-2), 63 - 8
{Bacterial flora in pharyngitis and tonsillitis}; Radosz-Komoniewska H et al.; The aim of the study was a microbiological analysis of pharyngeal swabs obtained from 158 patients with the diagnosis of pharyngitis and purulent exudates from the tonsillar crypts of 10 patients treated for chronic purulent tonsillitis . Beta haemolytic streptococci groups A, B, C and G were isolated from 30% of the patients . The most frequently isolated were Streptococcus pyogenes--12% of patients and Streptococcus group C--10.7% . Other streptococci were isolated less frequently: Streptococcus group B--44%, group G--2.5% . The majority of isolated bacteria belonged to potential pathogenic flora (70% patients) . Staphylococcus aureus (37%) and Haemophilus spp . (36%) were isolated most frequently . Other bacteria were isolated in the following sequence: Moraxella catarrhalis--22%, Streptococcus pneumoniae--17% and Gram-negative rods from the Enterobacteriaceae family--6% . One case of Plaut-Vincent tonsillitis was diagnosed . Aerobic and anaerobic bacteria were isolated from purulent exudates from the tonsillar crypts of 10 patients treated for chronic purulent tonsillitis . The isolated anaerobic bacteria belonged to genus of Prevotella, Fusobacterium, Peptostreptococcus and Gemella.

Med Dosw Mikrobiol, 1998, 50(1-2), 41 - 6
{Evaluation of in vitro susceptibility of hospital bacterial isolates to piperacillin and tazocin (piperacillin/tazobactam}; Birawska I et al.; Due to increasing frequency of infections caused by pathogens that are resistant to beta-lactam antibiotics, combinations of such antibiotics and beta-lactamase inhibitors were introduced into therapy in last few years . Tazobactam is the most potent beta-lactamase inhibitor . The purpose of the study was to evaluate in vitro susceptibility to piperacillin and piperacillin with tazobactam of 256 isolates cultured from biological samples obtained from 203 patients . The biological materials obtained were as follows: urine (44.9%), post-operative and post-traumatic wound swabs (27.3%), BAL (12.1%), blood (6.6%), drain swabs and other (5.5%) . The isolates predominantly found were Escherichia coli (22.3%), Pseudomonas aeruginosa (16.0%), Staphylococcus aureus MSSA (13.7%), Proteus mirabilis (11.7%) and other . There were 95.5% of strains found susceptible to piperacillin with tazobactam and only 4.3% resistant ones . On the other hand, piperacillin only susceptible strains were 59.4% and resistant ones in 40.6% . Great differences in susceptibility to examined antimicrobial agents were observed in Enterobacteriaceae family and Staphylococcus (MSS) genus . There were no differences in susceptibility to piperacillin and tazobactam and piperacillin alone in anaerobic Enterobacteriaceae strains and non-fermenting Gram-negative bacilli.

Med Dosw Mikrobiol, 1998, 50(1-2), 31 - 9
{Occurrence of extended spectrum beta-lactamases (ESBL) and inducible beta-lactamases (IBL) in clinical strains of gram-negative rods}; Rokosz A et al.; This study was undertaken to check the situation concerning the occurrence of Gram-negative rods producing extended-spectrum beta-lactamases (ESBL) and inducible beta-lactamases (IBL) in clinical specimens from patients hospitalized in National Clinical Hospital No . 1 in Warsaw . Such determinations were not performed in this hospital so far . During three months (April-June, 1997) 200 strains of Gram-negative rods were cultured . The strains were identified in automatic ATB system using strips with biochemical tests: ID 32 E for enteric rods and ID 32 GN for non-fermenting rods . ESBL-producing strains were detected with double disc diffusion test according to Jarlier et al . (1988) . Clavulanate was applied as the inhibitor of beta-lactamases (AMO/CLAV disc) . Inducible beta-lactamases were determined using double disc method according to Sanders and Sanders (1979) . Cefoxitin was the inductor of these beta-lactamases . 82 strains (41% of all strains) belonging to Enterobacteriaceae family, 92 strains (46%) of Pseudomonadaceae rods and 26 strains (13%) of other Gram-negative rods were isolated . 30 ESBL-producing strains (15% of all strains) and 45 strains (22.5%) with IBL activity were detected . The obtained results confirm the necessity of continuous and reliable monitoring of ESBL--and IBL--producing strains among Gram-negative rods isolated from clinical materials . The aims of such procedure are the control and prevention of their dissemination within a hospital as well as the avoidance of therapeutic failures.

Br J Fam Plann, 1998 Oct, 24(3), 95 - 7
A review of bacteriological culture of removed intrauterine contraceptive devices; Lewis R; A retrospective review of clinical and microbiological data was made, over an 18 month period, of intrauterine contraceptive devices removed and sent for examination . An association with symptoms at time of removal was found for Streptococcus agalactiae, Streptococcus milleri, enterobacteria and obligate anaerobes . Thirty four per cent of IUDs yielded one or more Actinomycesspecies spp but no correlation with symptoms was found . In the small group of symptomatic patients who were followed up, no difference in outcome was observed between those who were treated with antibiotics and those who were notPIP: Although the bacterial flora of the vagina and ectocervix are known to vary considerably between individuals, they remain rather constant over time in a given person . Findings are presented from a study conducted to relate the results of a simple qualitative bacteriological protocol, applied to removed IUDs received in the laboratory between January 1994 and October 1995, to the clinical presentations and outcome of the patients from whom they were taken . 218 IUDs removed from 217 women were examined during the study period, of which 123 were included in the study . Highly diverse culture results were obtained from the IUDs . An association with symptoms at time of removal was found for Streptococcus agalactiae, S . milleri, enterobacteria, and obligate anaerobes . 34% of IUDs yielded one or more Actinomyces species, but no correlation with symptoms was found . In the small group of symptomatic patients who were followed up, no difference in outcome was observed between those who were treated with antibiotics and those who were not . When IUDs are removed from women experiencing symptoms potentially related to their IUD use and sent for culture, the results should be awaited before beginning therapy on the basis of only clinical symptoms .

J Clin Microbiol, 1999 Jan, 37(1), 103 - 9
Typing of Listeria monocytogenes strains by repetitive element sequence-based PCR; Jersek B et al.; Listeria monocytogenes strains possess short repetitive extragenic palindromic (REP) elements and enterobacterial repetitive intergenic consensus (ERIC) sequences . We used repetitive element sequence-based PCR (rep-PCR) to evaluate the potential of REP and ERIC elements for typing L . monocytogenes strains isolated from humans, animals, and foods . On the basis of rep-PCR fingerprints, L . monocytogenes strains were divided into four major clusters matching origin of isolation . rep-PCR fingerprints of human and animal isolates were different from those of food isolates . Computer evaluation of rep-PCR fingerprints allowed discrimination among the tested serotypes 1/2a, 1/2b, 1/2c, 3b, and 4b within each major cluster . The index of discrimination calculated for 52 epidemiologically unrelated isolates of L . monocytogenes was 0.98 for REP- and ERIC-PCR . Our results suggest that rep-PCR can provide an alternative method for L . monocytogenes typing.

Arch Pediatr, 1998 Nov, 5(11), 1216 - 20
{Bacteriologic surveillance of nosocomial septicemia and bacteremia in a pediatric hospital}; Gayvallet-Montredon N et al.; BACKGROUND: Nosocomial bloodstream infections in pediatrics are an important cause of morbidity and mortality . To identify pathogens causing nosocomial bloodstream infections, evaluate associated risk factors and take preventive measures, we conducted a prospective study from January 1995 to December 1995 at Saint-Vincent-de-Paul Hospital (Paris) . PATIENTS AND RESULTS: All patients hospitalized more than 48 hours were included in the study . During this period, we recorded 21 bloodstream infections in 20 children . The incidence rate of nosocomial bloodstream infection was 1/1,000 admissions . Sixteen children were hospitalized in surgery, three in medical intensive care unit; the median day onset of infection was approximately 20 days . Recorded risk factors were: surgery, invasive procedures, central catheterization, bladder catheters, parenteral nutrition, device, endotracheal tube, antibiotic therapy before infection . The number of risk factors ranged from zero to six per patient . The most common isolated pathogens were in ten cases Gram positive cocci: five methicillin-sensible Staphylococcus aureus, four methicillin-resistant coagulase-negative staphylococci and one Streptococcus milleri . Other bacteria were seven enterobacteria, three Pseudomonas sp and three Candida sp . In 11 cases, the same bacteria as in bloodstream infection could be found: in three urine samples, in two tracheal samples, in two gastro-intestinal samples, two puncture sites, one device, and one umbilical catheter . CONCLUSION: In our study, 6.2% of positive blood culture were due to a nosocomial infection . We confirm the importance of Gram positive cocci, and particularly of methicillin-resistant coagulase negative staphylococci.

Gynecol Obstet Invest, 1999, 47(1), 42 - 4
Urinary bacterial flora of women with urethral syndrome and interstitial cystitis; Haarala M et al.; The aerobic and anaerobic bacterial flora in the first voided and in the midstream urine of healthy females (n = 5) and female patients with either urethral syndrome (US) (n = 5) or interstitial cystitis (IC) (n = 14) were studied . Bacteria were grown on media enabling isolation of fastidious and aerobic as well as obligatory anaerobic species . In healthy females only gram-positive rods were found whereas US patients also harbored streptococci . Patients with IC presented also with Enterobacteriae and anaerobic bacteria . Five IC patients with severe symptoms were treated with metronidazole; 2 out of 3 patients with anaerobic bacteria in the pretreatment specimens had no anaerobes after metronidazole therapy and in 1 patient streptococci disappeared after the therapy . One patient with severe symptoms and Bacteroides fragilis in the midstream urine became symptom-free after 2 weeks of metronidazole treatment . Although there is uncertainty whether the US and IC are not related to an infectious etiology, the bacterial flora in urethral and in midstream urine in these conditions differs considerably from that of healthy females.

Hum Reprod, 1998 Nov, 13(11), 3128 - 31
Febrile morbidity in severe and critical ovarian hyperstimulation syndrome: a multicentre study; Abramov Y et al.; The objective of this study was to define the incidence of febrile morbidity and its causes in severe and critical ovarian hyperstimulation syndrome (OHSS) . For this purpose, we reviewed the medical records of all OHSS patients hospitalized in 16 out of 19 tertiary medical centres in Israel between January 1987 and December 1996 . Febrile morbidity was defined as at least one episode of temperature rise above 38 degrees C lasting > or =24 h . A total of 2902 patients (3305 hospitalizations) with OHSS was identified, of whom 196 had severe, and 13 critical, OHSS . Among the 209 patients investigated the incidence of febrile morbidity was 82.3%, of which 20.5% was attributed to urinary tract infection, 3.8% to pneumonia, 3.3% to upper respiratory tract infection, 2.0% to intravenous line phlebitis, 1.0% to cellulitis at an abdominal puncture site, 1.0% to postoperative wound infections and 0.5 % to gluteal abscess at the site of progesterone injection . Non-typical organisms were frequently isolated, such as Pseudomonas, Proteus, Klebsiella and Enterobacter species . No infectious aetiology was found in 105 patients (50.2%) . Hypoglobulinaemia was recorded in most patients, while ascitic and pleural fluids aspirated from these patients contained high globulin concentrations . We conclude that infection-related febrile morbidity in severe and critical OHSS is high, and may be attributed to some degree of immunodeficiency associated with loss of plasma globulins to the third space . However, non-infection-related febrile morbidity is even higher and may be attributed to endogenous pyrogenic mechanisms.

Microbios, 1998, 94(379), 133 - 43
Characterization of arylamine N-acetyltransferase in Enterobacter aerogenes; Tsou MF et al.; N-acetyltransferase (NAT) activity was determined by incubation of purified Enterobacter aerogenes enzyme with 2-aminofluorene (2-AF) as the substrate, followed by high pressure liquid chromatography assays . The NAT activity from E . aerogenes was 0.58 +/- 0.08 nmol/min/mg protein for 2-AF . The values of apparent K(m) and Vmax were 0.72 +/- 0.14 mM and 2.45 +/- 0.29 nmol/min/mg protein, respectively, for 2-AF . The optimal pH value for the enzyme activity was 7.5 for the 2-AF tested . The optimal temperature for enzyme activity was 37 degrees C for the 2-AF substrate . The molecular weight of NAT from E . aerogenes was 44.9 kD . Among a series of divalent cations and salts, Zn2+, Ca2+, and Fe2+ were demonstrated to be the most potent protease inhibitors, and only ethylenediaminetetraacetic acid significantly protected the NAT . Iodoacetamide, in contrast to other agents, markedly inhibited NAT.

J Bacteriol, 1998 Dec, 180(24), 6743 - 8
Superimposition of tyrR protein-mediated regulation on osmoresponsive transcription of Escherichia coli proU in vivo; Gowrishankar J et al.; Osmotic regulation of proU expression in the enterobacteria is achieved, at least in part, by a repression mechanism involving the histone-like nucleoid protein H-NS . By the creation of binding sites for the TyrR regulator protein in the vicinity of the sigma70-controlled promoter of proU in Escherichia coli, we were able to demonstrate a superposed TyrR-mediated activation by L-phenylalanine (Phe), as well as repression by L-tyrosine, of proU expression in vivo . Based on the facts that pronounced activation in the presence of Phe was observed even at a low osmolarity and that the affinity of binding of TyrR to its cognate sites on DNA is not affected by Phe, we argue that H-NS-mediated repression of proU at a low osmolarity may not involve a classical silencing mechanism . Our data also suggest the involvement of recruited RNA polymerase in the mechanism of antirepression in E . coli.

Can J Microbiol, 1998 Sep, 44(9), 833 - 43
Isolation and characterization of ACC deaminase genes from two different plant growth-promoting rhizobacteria; Shah S et al.; We have recently proposed that one way that plant growth-promoting rhizobacteria (PGPR) stimulate plant growth is through the activity of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which causes a lowering of plant ethylene levels resulting in longer roots . As part of an effort to understand the role of this enzyme in PGPR, the genes for ACC deaminase from two PGPR, Enterobacter cloacae CAL2 and UW4, have been isolated . These genes are highly homologous to the ACC deaminase genes from Pseudomonas strains 6G5 and F17 and similar to the ACC deaminase gene from Pseudomonas sp . strain ACP . The region downstream (i.e., at the 3'-terminal end) of the strain UW4 ACC deaminase gene has a potential hairpin-like transcription termination site . The regions upstream of the strains UW4 and CAL2 ACC deaminase genes contain putative ribosome-binding sites; however, the promoter sequences have not yet been identified . Southern hybridization experiments suggest that there is a single copy of the ACC deaminase gene in Enterobacter cloacae strains UW4 and CAL2 and that there may be several different types of ACC deaminase genes in different microbes . The cloned ACC deaminase gene can be expressed in Escherichia coli enabling this bacterium to grow on ACC as a sole source of nitrogen and confers upon both Escherichia coli and Pseudomonas spp . strains that are transformed with this gene the ability to promote the elongation of the roots of canola seedlings.

Eur J Epidemiol, 1998 Oct, 14(7), 701 - 10
Serotype and phage type distribution of salmonellas from human and non-human sources in Italy in the period 1973-1995; Fantasia M et al.; According to the data collected at the Rome-based National Reference Centre for Enterobacteria, 266,547 Salmonella strains isolated from human sources (226,513) and from non human sources (40,034) were characterised in Italy during the period 1973-1995 . The serotype of all isolates, and the antibiotype and phage type of selected isolates were determined . Human-source isolations grew from 4372 in 1973 to 12,310 in 1995: non-human source isolations, from 339 in 1973 to 3459 in 1995 . Salm.Typhimurium ranked first in the list of the most common serotypes isolated from both sources in the period 1973-1988 except in the years 1975 and 1976 when it was overtaken by Salm . Wien . Since 1983 Salm . Enteritidis has been among the top ten isolates from animals, and ranked first in the list of isolates from humans in 1988 and from non human sources in 1991 . During the last years the number of multidrug-resistant strains, mostly belonging to phage types 104 and 193 of Salm . Typhimurium has been rising . Salmonella strains have also been isolated from numerous extraintestinal infections, almost exclusively caused by Salm . Enteritidis and Typhimurium.

J Burn Care Rehabil, 1998 Nov-Dec, 19(6), 512 - 5
Is the limulus amebocyte lysate the sole predictor of septic episodes in major thermal injuries?
Heggers JP, Goodheart R, Carino E, McCoy L, Ramirez RJ, Maness C.
Septic episodes in thermal injuries are usually hallmarked by a series of physiologic parameters that include tachypnea, prolonged paralytic ileus, hyperthermia or hypothermia, altered mental status, thrombocytopenia, leukocytosis or unexplained leukopenia, acidosis, and hyperglycemia . Recent studies with polycystic kidney disease have clearly indicated that the limulus amebocyte lysate (LAL) assays were predictive of fungal infections in this patient population . Because both bacteria and fungi produce lipopolysaccharide that can be identified with the LAL assay, we randomly assayed sequential sera of 45 patients with major thermal injuries for positivity in the LAL assay, with use of the QCL-1000 kit (BioWhittaker, Walkersville, Md) . The average burn size of this patient population was 63.43% total body surface area . The average age of the patient was 6.2 years . The sex distribution included 30 males and 15 females . The infectious agents included gram-positive cocci and gram-negative rods, and 14 patients had concomitant fungal infections . Eighty-five percent of the patients tested were positive for endotoxin, with levels ranging from < 0.1 EU/mL to > 1.0 EU/mL . The predominant organism isolated before or on the date the serum was drawn was Pseudomonas aeruginosa (51%), followed by Klebsiella pneumoniae (15%) . The remaining 34% were a variety of Enterobacteriaceae . Of the 14 patients who yielded a fungus, 3 had negative LAL assays . Two patients with an elevated LAL grew only Staphylococcus epidermidis in the bloodstream and the wounds . These data clearly indicate that the LAL assay cannot be relied on as the sole predictor of septic episodes; however, it can be an adjunctive test to confirm sepsis when the other parameters have been considered.

Am J Nephrol, 1998, 18(6), 485 - 9
A cluster of bloodstream infections and pyrogenic reactions among hemodialysis patients traced to dialysis machine waste-handling option units; Jochimsen EM et al.; From June 17 through November 15, 1995, ten episodes of Enterobacter cloacae bloodstream infection and three pyrogenic reactions occurred in patients at a hospital-based hemodialysis center . In a case-control study limited to events occurring during October 1-31, 1995, seven dialysis sessions resulting in E . cloacae bacteremia or pyrogenic reaction without bacteremia were compared with 241 randomly selected control sessions . Dialysis machines were examined, dialysis fluid and equipment were cultured, and E . cloacae isolates were genotyped by pulsed-field gel electrophoresis . Each dialysis machine had a waste-handling option (WHO) through which dialyzer-priming fluid was discarded before each dialysis session; in 7 of 11 machines, one-way check valves designed to prevent backflow from the WHO into patient bloodlines were dysfunctional . In the case-control study, case sessions were more frequent when machines with >/=1 dysfunctional check valves were used . E . cloacae with identical pulsed-field gel electrophoresis patterns were isolated from case patients, dialysis fluid, station drains, and WHO units . Our investigation shows that bloodstream infections and pyrogenic reactions were caused by backflow from contaminated dialysis machine WHO units into patient bloodlines . The outbreak was terminated when WHO use was discontinued, check valves were replaced, and dialysis machine disinfection was enhanced.

Microbiology, 1998 Nov, 144 ( Pt 11), 3003 - 9
Porin alteration and active efflux: two in vivo drug resistance strategies used by Enterobacter aerogenes; Mallea M et al.; Enterobacter aerogenes is among the five most frequently isolated nosocomial pathogens in France, and this bacterium also shows increasing multidrug resistance . In this study, various E . aerogenes strains isolated from hospital units were characterized for their outer-membrane proteins, antibiotic susceptibilities (inhibition diameters and MICs) and resistance mechanisms associated with modification of envelope permeability (porin alteration and active efflux) . Diminished outer-membrane permeability due to porin alterations was found in conjunction with the expression of an enzymic barrier in resistant isolates . Interestingly, changes in the functional expression of porins appeared to play a special role in susceptibility to cefepime . An active efflux to quinolones was also identified . Simultaneous changes in envelope permeability, i.e . a porin deficiency (in) and an efflux mechanism (out), were clearly evident in two clinical strains.

Jpn J Antibiot, 1998 Sep, 51(9), 551 - 60
{Antimicrobial activity of carbapenem antibiotics against gram-negative bacilli}; Kinoshita S et al.; Antimicrobial activities of meropenem (MEPM), imipenem (IPM), panipenem (PAPM), ceftazidime (CAZ), cefozopran (CZOP), aztreonam (AZT), norfloxacin (NFLX) and tetracycline (TC) against clinically isolated Gram-negative bacilli {271 strains of Enterobacteriaceae and 242 strains non-fermentative Gram-negative bacteria (NFB)} were investigated . Among carbapenem antibiotics, MEPM showed the lowest MIC90, which activity was about four-hold higher than those of IPM and PAPM . The activity of IPM was equal or slightly superior to that of PAPM . Resistance to IPM (> 16 micrograms/ml) was observed in 3 strains of Enterobacteriaceae (1.1%) and 14 strains of NFB (5.8%) . It is conceivable that these strains produce metallo-beta-lactamase . Referring to the correlation among MICs of MEPM, IPM and PAPM, 3 strains in 3 species of Enterobacteriaceae showed cross resistance to carbapenems; while 14 strains of NFB showed cross resistance to MEPM and IPM, 15 strains to MEPM and PAPM, and 29 strains to IPM and PAPM, and all of these strains were Pseudomonas aeruginosa . Fifteen of 29 strains of IPM-resistant and 77 of 92 strains of PAPM-resistant P . aeruginosa were susceptible to MEPM . Thirty-three strains (12%) of the Enterobacteriaceae were resistant to CAZ and AZT (> or = 32 micrograms/ml) and these were considered as ESBL-producing strains.

Eur J Pharm Sci, 1999 Jan, 7(2), 153 - 60
Synthesis and antimicrobial activity of some novel 2,5- and/or 6-substituted benzoxazole and benzimidazole derivatives; Oren I et al.; A new series of 2,5- and/or 6-substituted benzoxazoles (7a-f), benzimidazoles (8a-g) holding cyclohexyl or cyclopentyl moieties at position 2 and 5- or 6-substituted-2-cyclohexylaminomethylbenzoxazoles (9a, b) was synthesized in order to determine their antimicrobial activities and feasible structure-activity relationships . The synthesized compounds were tested in vitro against three Gram-positive, two Gram-negative bacteria and the yeast Candida albicans in comparison with several control drugs . Microbiological results showed that the synthesized compounds were possessing a broad spectrum of antibacterial activity against the tested microorganisms . 5-Chloro-2-(2-cyclohexylethyl)benzimidazole (8g) was found as the most active compound against the screened Gram-positive bacteria strains at a minimum inhibitory concentration (MIC) value of 12.5 microg/ml . However, it exhibited lower antibacterial potency than the compared control drugs . On the other side, compounds 7-9 indicated significant antibacterial activity against the Gram-negative enterobacter Pseudomonas aeruginosa having MIC values of 50 microg/ml, providing either the same effect as tetracycline or higher activity than streptomycin, but showing less potency than the compared control drug gentamycin . Moreover, the synthesized compounds also possessed antimycotic activity against the yeast C . albicans showing MIC values between 25-50 microg/ml.

Syst Appl Microbiol, 1998 Aug, 21(3), 346 - 52
Phosphate starvation-independent 2-aminoethylphosphonic acid biodegradation in a newly isolated strain of Pseudomonas putida, NG2; Ternan NG et al.; A strain of Pseudomonas putida that utilized the biogenic organophosphonate 2-aminoethylphosphonic acid as sole carbon and energy, nitrogen and phosphorus source contained 2-aminoethylphosphonic acid: pyruvate aminotransferase and phosphonoacetaldehyde hydrolase (phosphonatase) activities which were inducible by the presence of 2-aminoethylphosphonic acid in the culture medium, regardless of the phosphate status of the cells . Neither of these activities were induced in their phosphate-free or phosphate-replete medium in the absence of 2-aminoethylphosphonic acid . Alkaline phosphatase activity was induced in phosphate limited medium, however, indicating a phosphate-starvation inducible response . In Enterobacter aerogenes IFO 12010, 2-aminoethylphosphonate: pyruvate aminotransferase and phosphonatase activities were induced only when cells were both phosphate limited and supplied with 2-aminoethylphosphonic acid as sole phosphorus source for growth . Neither enzyme activity was induced in phosphate-replete medium, or in medium where both 2-aminoethylphosphonic acid and inorganic phosphate were supplied as sources of phosphorus . The results point to the presence of a substrate inducible 2-aminoethylphosphonic acid biodegradation pathway in the isolated strain of Pseudomonas putida . Uniquely, therefore, the pathway is not under pho regulon control in this strain.

Plant Foods Hum Nutr, 1998, 52(1), 37 - 47
Microbial populations associated with the retting of melon pods (Colocynthis citrullus L.) during seed recovery; Offonry SU et al.; The traditional process for the retting of melon pulp and microbiological characteristics in the recovery of melon seeds (Colocynthis citrullus L.) were investigated . Melon pods were sliced open and exposed for seven days . The pulp underwent a natural fermentation that was characterized by the growth of microorganisms to 10(8)-10(10) cfu/g . The pH fluctuated between 4.8 and 5.1 with a lactic acid content of 0.72% . Bacillus subtilis, B . polymyxa, Lactobacillus fermentum, L . brevis and Streptococcusfaecalis were the predominant microorganisms but, significant contributions were made by Staphylococcus saprophyticus and Enterobacter cloacae . Penicillium, Aspergillus and Rhizopus species including the yeasts, Saccharomyces cerevisiae, Candida krusei and Deboromyces hansenii were isolated from the fermentation . Growth of microorganisms was completely inhibited in antibiotic-treated samples indicating that the melon pods were the main source of microorganisms for the fermentation.

J Med Microbiol, 1998 Jul, 47(7), 629 - 42
Natural antibiotic susceptibility of Providencia stuartii, P . rettgeri, P . alcalifaciens and P . rustigianii strains; Stock I et al.; The natural antibiotic susceptibility of 38 Providencia rettgeri, 35 P . stuartii, 23 P . alcalifaciens and 20 P . rustigianii strains was examined . MIC values were determined by a microdilution procedure and evaluated by a table calculation programme . P . stuartii was the least susceptible Providencia sp . and was naturally resistant to tetracyclines, some penicillins, older cephalosporins, sulphamethoxazole and fosfomycin and to antibiotics to which other species of Enterobacteriaceae are also resistant . It was naturally sensitive to modern penicillins and cephalosporins, carbapenems and aztreonam, but its susceptibility to aminoglycosides and quinolones was difficult to assess . P . alcalifaciens and P . rustigianii strains were the most susceptible Providencia spp . They were naturally sensitive or intermediate to tetracyclines and sensitive to aminoglycosides and quinolones . Susceptibility to sparfloxacin, biapenem and sulphamethoxazole permitted the discrimination of P . alcalifaciens and P . rustigianii strains . The natural antibiotic susceptibility of P . rettgeri strains was between that of P . stuartii and that of the other providenciae . P . rettgeri was resistant to tetracyclines and fosfomycin, but more susceptible to aminoglycosides, quinolones, fosfomycin and numerous beta-lactam antibiotics than P . stuartii . A database is described of the natural antibiotic susceptibilities of Providencia spp . It can be used for the validation of antibiotic susceptibility test results of these micro-organisms.

Appl Environ Microbiol, 1998 Dec, 64(12), 4743 - 7
Purification and characterization of gallic acid decarboxylase from pantoea agglomerans T71
Zeida M, Wieser M, Yoshida T, Sugio T, Nagasawa T.
Oxygen-sensitive gallic acid decarboxylase from Pantoea (formerly Enterobacter) agglomerans T71 was purified from a cell extract after stabilization by reducing agents . This enzyme has a molecular mass of approximately 320 kDa and consists of six identical subunits . It is highly specific for gallic acid . Gallic acid decarboxylase is unique among similar decarboxylases in that it requires iron as a cofactor, as shown by plasma emission spectroscopy (which revealed an iron content of 0.8 mol per mol of enzyme subunit), spectrophotometric analysis (absorption shoulders at 398 and 472 nm), and inhibition of the enzyme activity by 2,2'-bipyridyl, o-phenanthroline, and EDTA . Another interesting feature of this strain is the fact that it contains a tannase, which is used together with the gallic acid decarboxylase in a two-enzyme resting cell bioconversion to synthesize valuable pyrogallol from readily available tannic acid.

Antimicrob Agents Chemother, 1998 Dec, 42(12), 3304 - 8
Efficacies of cefepime, ceftazidime, and imipenem alone or in combination with amikacin in rats with experimental pneumonia due to ceftazidime-susceptible or -resistant Enterobacter cloacae strains; Mimoz O et al.; The antibacterial activities of human regimens of cefepime, ceftazidime, and imipenem alone or in combination with amikacin against an isogenic pair of Enterobacter cloacae strains (wild type and its corresponding derepressed cephalosporinase mutant) were compared by using our nonlethal model of pneumonia with 180 immunocompetent rats . Compared with untreated animals, all beta-lactam-treated rats, except those inoculated with the mutant isolate and receiving ceftazidime, had significantly lower bacterial counts in their lungs 60 h after the onset of therapy . Although the combination of a beta-lactam and amikacin was more bactericidal than each corresponding antimicrobial agent alone, true synergy was noted only with cefepime and imipenem against the constitutive derepressed strain.

Antimicrob Agents Chemother, 1998 Dec, 42(12), 3296 - 300
An ampD gene in Pseudomonas aeruginosa encodes a negative regulator of AmpC beta-lactamase expression; Langaee TY et al.; The ampD and ampE genes of Pseudomonas aeruginosa PAO1 were cloned and characterized . These genes are transcribed in the same orientation and form an operon . The deduced polypeptide of P . aeruginosa ampD exhibited more than 60% similarity to the AmpD proteins of enterobacteria and Haemophilus influenzae . The ampD product transcomplemented Escherichia coli ampD mutants to wild-type beta-lactamase expression.

Enferm Infecc Microbiol Clin, 1998 Oct, 16(8), 364 - 6
{Enterobacter amnigenus . An unusual human pathogen}; Capdevila JA et al.; BACKGROUND: Enterobacter amnigenus is a bacteria with doubtful pathogenicity . The observation of a patient with a well-documented E . amnigenus infection has prompted us to review the pathology caused by this microorganism . METHODS: Retrospective evaluation of the clinical charts of patients with any isolate positive for E . amnigenus over a period of 46 months . Based on the clinical data, presence or absence of other causal microorganisms and/or alternative diagnosis, E . amnigenus was classified as definitive, probable, or improbable cause of infection . RESULTS: We analyzed 15 E . amnigenus isolates, representing 0.97 of 10,000, the total bacterial isolates in our laboratory for this period, and 0.52% of those corresponding to Enterobacter sp . We were able to clinically evaluate E . amnigenus in 7 patients, in whom infection by this microorganism was classified as definitive in 4, probable in 1, and improbable in 2 . Antibiotic susceptibility studies showed a resistance level of 83% to ampicillin, 75% to cefazoline and cefoxitine, and 33% to amoxicillin-clavulanic acid . All isolates were susceptible to third-generation cephalosporins, aztreonam, ciprofloxacin, cotrimoxazole and aminoglycosides . CONCLUSIONS: E . amnigenus cause well-documented bacterial infection in man . Thus, isolation of this microorganism should not be considered as a contaminant or simple colonizer . The clinical behavior and antimicrobial susceptibility of E . amnigenus is similar to that of E . cloacae, a taxonomically-related species.

Arch Orthop Trauma Surg, 1998, 118(1-2), 32 - 6
Teicoplanin in the prevention of infection in total hip replacement; Nehrer S et al.; Perioperative antibiotic prophylaxis has been shown to be effective in reducing postoperative wound infections . The rising incidence of infections secondary to methicillin-resistant strains of Staphylococcus aureus . S . epidermidis and S . enterococcal prompted us to administer Teicoplanin to infection in elective total joint arthroplasty . In 111 patients Teicoplanin was given in a single intravenous dose of 10 mg/kg prior to surgery . In the postoperative period no deep infection of the prosthetic device was found in a 14-month follow-up . In two patients the following organisms were isolated from superficial infections of the wound: S . epidermidis (methicillin-sensitive), Pseudomonas aeruginosa, and Enterobacter sp . In no patient was revision surgery necessary . The serum concentration of Teicoplanin was within the therapeutic range during surgery, and tissue levels of Teicoplanin in cancellous (6.2 mg/kg, range 3.8-10.9 mg/kg) and cortical (7.1 mg/kg, range 2.6-12.1 mg/kg) bone during surgery in 16 patients exceeded the minimum inhibitory concentration of 90% (MIC90) of methicillin-resistant strains reported for methicillin-resistant strains . In our experience a single dose regimen of Teicoplanin is a safe and effective method of antibiotic prophylaxis in hip joint replacement, particularly when methicillin-resistant bacteria are present.

Clin Ther, 1998 Sep-Oct, 20(5), 885 - 900
Etiology, susceptibility, and treatment of acute bacterial exacerbations of complicated chronic bronchitis in the primary care setting: ciprofloxacin 750 mg b.i.d . versus clarithromycin 500 mg b.i.d . Bronchitis Study Group; Anzueto A et al.; Although controversial, antimicrobial therapy for the treatment of acute exacerbations of chronic bronchitis (AECB) appears beneficial in patients with a history of repeated infections, those who have comorbid illnesses, and those with marked airway obstruction . In a community-based, open, randomized trial, the efficacy and safety of ciprofloxacin (CIP) 750 mg and clarithromycin (CLA) 500 mg, each given twice daily for 10 days, were compared in 2180 patients with AECB (1083 CIP, 1097 CLA) . Patients were >40 years of age and had complicated/severe AECB episodes defined as at least three episodes within the past year, at least three comorbid conditions, previous failed antibiotic treatment for AECB within the previous 2 to 4 weeks, or community susceptibility data indicating a high number of resistant pathogens . Significant bacterial isolates (>10(5) colony-forming units per milliliter) from homogenized sputa were identified . Susceptibility to a range of antimicrobials was determined by the microbroth dilution technique . The majority of patients were white (83%) and were current or previous smokers (81%) . Mean patient age was 62 years . A history of at least three AECB episodes in the previous year was reported by 54% of CIP-treated patients and 53% of CLA-treated patients . Of 777 primary isolates positively identified and cultured from 673 patients, the bacterial pathogens isolated and their incidence included Haemophilus species, 28%; Moraxella catarrhalis, 18%; Enterobacteriaceae, 18%; Staphylococcus aureus, 17%; Streptococcus pneumoniae, 7%; and Pseudomonas aeruginosa, 4% . Beta-lactamase production was found in 38% of Haemophilus influenzae, 10% of Haemophilus parainfluenzae, and 85% of M catarrhalis isolates . Thirty-four percent of S pneumoniae isolates were resistant to penicillin (minimum inhibitory concentration > or =0.12 mg/L) . Among the 673 patients who were valid for clinical assessment and had a pretherapy pathogen isolated, clinical success and overall bacteriologic eradication rates at the end of therapy were 93% and 98% for CIP versus 90% and 96% for CLA . The differences between CIP and CLA did not reach statistical significance . Superinfections were reported significantly more frequently in CLA-treated (3%) versus CIP-treated patients (1%) . Eradication rates for specific organisms for CIP and CLA, respectively, were Haemophilus species, 99% and 93%; M catarrhalis, 99% and 100%; S pneumoniae, 91% and 92%; and Enterobacteriaceae, 100% and 95% . Drug-related adverse events occurred in 12% of CIP-treated patients and 10% of CLA-treated patients . CIP 750 mg b.i.d . had a higher (but not statistically significant) clinical and bacteriologic cure rate than CLA 500 mg b.i.d . in the treatment of patients with bacteriologically proven complicated/severe AECB . The causative bacterial pathogens of AECB appear to be evolving, with a predominance of gram-negative and other resistant organisms observed . Thus antibiotic therapy for at-risk patients with AECB should include agents that have activity against gram-negative pathogens.

Drugs, 1998 Nov, 56(5), 895 - 928
Ofloxacin . A reappraisal of its use in the management of genitourinary tract infections; Onrust SV et al.; Ofloxacin is an established fluoroquinolone agent which achieves good concentrations in genitourinary tract tissues and fluids . It has good in vitro activity against most Enterobacteriaceae, Staphylococcus saprophyticus, methicillin-susceptible S . aureus, Neisseria gonorrhoeae, Chlamydia trachomatis and Haemophilus ducreyi, intermediate activity against Ureaplasma urealyticum and most enterococci, but limited or no in vitro activity against enterococci, Serratia marcescens, Pseudomonas aeruginosa and many anaerobes . However, high concentrations achieved in the urine ensure its activity against most urinary tract pathogens . Ofloxacin demonstrates consistent efficacy in a broad range of urinary tract infections, achieving bacteriological response rates in excess of 80% in uncomplicated and 70% in complicated infections . The efficacy of ofloxacin was similar to that of all comparators tested including other fluoroquinolones, cephalosporins and cotrimoxazole (trimethoprim/sulfamethoxazole) . Ofloxacin is also effective as a single-dose regimen in the treatment of uncomplicated gonorrhoea, as a 7-day regimen in uncomplicated C . trachomatis infections, and as monotherapy in uncomplicated pelvic inflammatory disease (PID) . Again, ofloxacin demonstrated similar efficacy to alternative treatments in each type of infection . The availability of an intravenous formulation and near-complete oral bioavailability allow ofloxacin to be administered as a sequential regimen without loss of activity . The tolerability and drug interaction profile of ofloxacin is consistent with that of other fluoroquinolones . The most commonly reported adverse events with ofloxacin are gastrointestinal, neurological and dermatological . It was associated with a lower incidence of photosensitivity and tendinitis and higher incidence of some neurological events than some other fluoroquinolones . Ofloxacin seems to have a lower propensity to interact with xanthines than other fluoroquinolones . Conclusion: ofloxacin has established efficacy in the treatment of a wide variety of urinary tract infections, although, like other fluoroquinolones, it should be used rationally to preserve its activity . Currently, ofloxacin also holds an important place among fluoroquinolones in the treatment of C . trachomatis infections and uncomplicated PID, although its acceptance as monotherapy in PID is likely to depend on clarification of the causative role of anaerobic pathogens in this infection.

J Clin Pathol, 1998 Aug, 51(8), 614 - 6
Changes in nature and antibiotic resistance of bacteria causing peritonitis in cirrhotic patients over a 20 year period; Dupeyron C et al.; AIM: To assess all clinically and bacteriologically documented episodes of spontaneous bacterial peritonitis diagnosed in a single unit over a 20 year period, to identify changes in the nature and antibiotic resistance of the causative bacteria . SETTING: A specialist liver disease unit in a tertiary care centre . MATERIAL: Cultured ascitic fluid obtained in the course of 240 consecutive episodes of clinically and bacteriologically proven spontaneous bacterial peritonitis . Patient recruitment remained stable during the 20 year period in terms of the number of cirrhotic patients admitted and the severity of their condition . RESULTS: 78.7% of isolates were Enterobacteriaceae (Escherichia coli in 51%) and 19% were Gram positive cocci . Until 1979 all the Enterobacteriaceae had the wild phenotype, compared with only 50% at the end of the study period . Since 1993, 22% of Enterobacteriaceae have been resistant to third generation cephalosporins . Methicillin resistant staphylococci were only isolated after 1989 . CONCLUSIONS: Changes in the epidemiology and antibiotic resistance of bacteria causing spontaneous bacterial peritonitis must be monitored for optimal treatment.

Clin Infect Dis, 1998 Nov, 27(5), 1204 - 9
Risk factors for Enterobacter septicemia in a neonatal unit: case-control study; Fok TF et al.; Thirty cases of Enterobacter aerogenes or Enterobacter cloacae septicemia diagnosed over a 32-month period in a tertiary care neonatal unit were enrolled in a case-control study . Each case patient was matched with two controls (patients occupying the cots nearest the case patient when the latter developed septicemia) . Of the 32 perinatal characteristics evaluated, 11 were identified by univariate analysis to be significantly associated with the infection . These included parents being residents of the Vietnamese refugee camps, respiratory distress syndrome, necrotizing enterocolitis, umbilical arterial catheterization, umbilical venous catheterization, bladder catheterization, mechanical ventilation, antibiotic treatment, peripheral venous catheterization, nasogastric intubation, and parenteral nutrition . Multivariate analysis, however, showed that preceding bladder catheterization and ongoing parenteral nutrition were the only independent risk factors for enterobacter septicemia . Strict aseptic technique in the preparation of parenteral nutrition fluid and avoidance of bladder catheterization are measures that may reduce the risk of enterobacter sepsis for newborns.

Dakar Med, 1997, 42(2), 123 - 6
{Sensitivity profiles of enterobacteria isolated at th Fann University Hospital Center, Dakar}; Sow AI et al.; This study concerns 180 strains of Enterobacteria isolated at Fann University Teaching Hospital (Dakar, Senegal) . The susceptibility to antibiotics was tested by disc diffusion test (antibiogram) and by dilution method determining the minimum inhibitory concentration (MIC) . All of the species present more resistant profile to beta-lactams (> 55%); however ceftriaxon and aztreonam present the lower MIC 50 (< 0.06 microgram/ml) . Fluoroquinolon inhibits more than 90% of the strains of E . Coli and Proteus . Chloramphenicol is active on Salmonella, but ceftriaxon, aztreonam and the fluoroquinolon present good alternatives . Cotrimoxazole is active only on 54% of Shigella strains.

Acta Paediatr, 1998 Oct, 87(10), 1070 - 4
Control of an outbreak of a highly beta-lactam-resistant Enterobacter cloacae strain in a neonatal special care unit; Finnstrom O et al.; Two successive outbreaks of colonization and infection with Enterobacter cloacae resistant to third generation cephalosporins (cephalosporin-resistant E . cloacae, CREC) and involving 15 infants occurred within 12 months in a neonatal special care unit . Isolates of clinical significance were obtained from four infants (urine 2 cases, blood, pleural drainage) . According to epidemiological typing using computerized biochemical fingerprinting and pulsed-field gel electrophoresis (PFGE) the same CREC strain was found in both outbreaks . The origin of the strain and its reservoir between the two outbreaks remained unknown . Emphasizing strict barrier nursing of the infants had little or no impact on the presence and transmission of the strain in the unit . In contrast, replacing ampicillin plus cefotaxime as standard empiric therapy with penicillin G plus netilmicin plus consequent cohorting of newborns and staff promptly halted both the outbreaks . During a 5-y follow-up after the last episode, the choice of antibiotics for empirical treatment has varied, and no further outbreaks of CREC have been seen, with the exception of two sporadic cases.

Zh Mikrobiol Epidemiol Immunobiol, 1998 Sep-Oct, (5), 54 - 7
{Antibodies to bacterial antigens and autoantigens in pregnant women with kidney diseases}; Ivanova OV et al.; The levels of antibodies (Ab) to bacterial antigens of gram-negative enterobacteria (Reglicolipid), Streptococcus agalactiae polysaccharide, Staphylococcus aureus teichoic acid, native and denatured DNA and renal proteins in healthy pregnant women and in those with renal pathology (chronic and gestation pyelonephritis) were studied . The study revealed that the combination of an elevated levels of Ab to bacterial antigens with the elevated titers of Ab to DNA and renal proteins is indicative of acute inflammation in kidneys, and but the combination of an elevated levels of Ab bacterial antigens with the low level of Ab to DNA and renal proteins is indicative of healthy carrier state with respect to a given infective agent.

Drugs Exp Clin Res, 1998, 24(3), 139 - 51
Antimicrobial activity of fluoroquinolones and other antibiotics on 1,116 clinical gram-positive and gram-negative isolates; Mascellino MT et al.; A total of 1,116 clinically isolated strains belonging to Staphylococcus aureus (200), Staphylococcus epidermidis (200), Streptococcus pneumoniae (20), Escherchia coli (200), Klebsiella spp . (177), Serratia marcescens (22), Pseudomonas aeruginosa (224), Haemophilus influenzae (35) and Salmonella (38) from the Department of Infectious Diseases, La Sapienza University in Rome (Italy) were tested against three fluoroquinolones (ofloxacin, ciprofloxacin and levofloxacin) and 10 other antibiotics (augmentin, ampicillin, cefaclor, cefixime, cefotaxime, cotrimoxazole, gentamicin, minocycline, oxacillin and vancomycin) . Fluoroquinolones inhibited essentially about 100% of H . influenzae, Salmonella and S . pneumoniae, more than 75% of Staphylococcus including methicillin-resistant strains, and about 90% of Enterobacteriaceae and 50% of P . aeruginosa . Minimal inhibitory concentration values ranged from < 0.015 to > 32 micrograms/ml for Klebsiella, S . aureus and epidermidis, E . coli and P . aeruginosa; from < 0.015 to 2 micrograms/ml for Salmonella; from 0.03 to 16 micrograms/ml for Serratia; from < 0.015 to 1 microgram/ml for Haemophilus; and from 0.5 to 2 micrograms/ml for S . pneumoniae . Levofloxacin and to a lesser extent ofloxacin and ciprofloxacin, generally exhibited a greater activity than the other agents against both Gram-positive and Gram-negative bacteria . Regarding the distribution of resistant strains in Italy, we found a peculiar pattern of resistance as far as E . coli and P . aeruginosa were concerned . Quality control parameters are also summarized . S . epidermidis resulted as a new emergent pathogen especially in immunocompromised patients and its level of sensitivity has been modified over the last few years . In fact, the percentage of resistant strains to antibiotics or the percentage of methicillin-resistant isolates (in our study 35%), has gradually increased . Levofloxacin and ofloxacin showed good activity against staphylococcal strains compared with the majority of other antibiotics . These results suggest that the newer quinolones are promising antimicrobial agents for various infections.

Antibiot Khimioter, 1998, 43(10), 36 - 41
{Efficacy of lomefloxacin in treatment of nonspecific inflammatory diseases and in prophylaxis of postoperative complications in urology}; Derevianko II et al.; Clinical and bacteriological efficacies of lomefloxacin and ofloxacin were comparatively estimated in the treatment of 104 urologic patients with nonspecific inflammatory diseases and in 36 urologic patients for prophylaxis of inflammatory complications after surgical interventions . The majority of the urinary tract pathogens i.e . Enterobacteriaceae spp . and gramnegative nonfermenting bacteria were highly susceptible to both the fluoroquinolones . The clinical and bacteriological efficacies of lomefloxacin amounted to 94.4 and 80.7 per cent and those of ofloxacin to 92 and 79.2 per cent respectively . The prophylactic use of lomefloxacin and ofloxacin was efficient in 94.7 and 94.1 per cent of the cases respectively . The antibacterial prophylaxis in urologic patients should be applied not only at the period of surgical interventions but also during the early postoperative period.

J Med Microbiol, 1998 Nov, 47(11), 1019 - 21
Analysis of neomycin, kanamycin, tobramycin and amikacin resistance mechanisms in gentamicin-resistant isolates of Enterobacteriaceae; Adwan K et al.; Twenty-four gentamicin-resistant isolates of Enterobacteriaceae, obtained from the clinical laboratories of three health centres in Nablus, Palestine, were tested for susceptibility to neomycin, kanamycin, tobramycin and amikacin . Resistance rates were 29.2% for neomycin, 58.3% for kanamycin, 45.8% for tobramycin and 8.3% for amikacin . Fourteen (58.3%) isolates were noted to be multiresistant, i.e., resistant to gentamicin and two or more other aminoglycosides; resistance to gentamicin, kanamycin and tobramycin was the most common pattern of multiple resistance . This pattern implies the involvement of adenyltransferase ANT(")-I activity . Plasmid profiles and curing experiments suggested a plasmid localisation of gentamicin, neomycin, kanamycin and tobramycin resistance genes . However, a chromosomal location is proposed for plasmid-deficient strains . Cross-resistance in two isolates to all aminoglycosides tested suggested membrane impermeability to aminoglycosides as the mechanism of resistance.

J Med Microbiol, 1998 Nov, 47(11), 987 - 92
PCR methods and plasmid profile analysis for characterisation of Histophilus ovis strains; Appuhamy S et al.; The value of polymerase chain reaction (PCR)-based DNA fingerprinting and plasmid profile analysis for differentiation of Histophilus ovis isolates was assessed . Nineteen isolates of H . ovis were typed by PCR-ribotyping, repetitive extragenic palindromic element (REP)-PCR and enterobacterial repetitive intergenic consensus (ERIC)-PCR . These methods distinguished five types by PCR-ribotyping, 11 types by REP-PCR and seven types by ERIC-PCR . The ribotyping method produced a relatively simple pattern and a small number of distinct types and was useful for differentiation of H . ovis from the phenotypically similar organism, Haemophilus somnus . REP- and ERIC-PCR both produced complex banding patterns, but increased the discrimination between strains . Plasmids were found in 12 of the 19 isolates and there were four different plasmid profiles . A combination of the PCR methods and plasmid profile analysis provided a high resolution typing method for H . ovis.

J Pediatr, 1998 Nov, 133(5), 640 - 4
Enterobacter cloacae and Pseudomonas aeruginosa polymicrobial bloodstream infections traced to extrinsic contamination of a dextrose multidose vial; Archibald LK et al.; OBJECTIVE: To identify risk factors for polymicrobial bloodstream infections (BSIs) in neonatal intensive care unit (NICU) patients during an outbreak of BSIs . DESIGN: During an outbreak of BSIs, we conducted a retrospective cohort study, assessed NICU infection control practices and patient exposure to NICU healthcare workers (HCWs), and obtained cultures of the environment and HCW hands . PATIENTS: During the period May 3 to 7, 1996, 5 infants contracted BSIs caused by both Enterobacter cloacae and Pseudomonas aeruginosa, and one infant contracted a BSI caused by E cloacae only . For each pathogen, all isolates were identical on DNA typing . RESULTS: Infants exposed to the following were more likely than nonexposed infants to have BSI: umbilical venous catheters (6/14 vs 0/7, P = .05), total parenteral nutrition given simultaneously with a dextrose/electrolyte solution (6/12 vs 0/9, P = .02), or one HCW (5/7 vs 1/13, P = .007) . Neither environmental nor HCW hand cultures yielded the outbreak pathogens . Quality control cultures of intravenous solution bags were negative . CONCLUSIONS: We speculate that a dextrose multidose vial became contaminated during manipulation or needle puncture and that successive use of this contaminated vial for multiple patients may have been responsible for BSIs . Aseptic techniques must be employed when multidose vial medications are used . Single-dose vials should be used for parenteral additives whenever possible to reduce the risk of extrinsic contamination and subsequent transmission of nosocomial pathogens.

Folia Microbiol (Praha), 1998, 43(4), 438 - 40
Gentamicin resistance in clinical strains of Enterobacteriaceae associated with reduced gentamicin uptake; Adwan K et al.; Seven strains of Enterobacteriaceae resistant to gentamicin obtained as representatives of the predominant resistance profiles in the clinical laboratories of Rafeidia and Al-Watani Hospitals in Nablus (Palestine) were included . Five strains showed a broad aminoglycoside resistance profile but contained no evidence of gentamicin acetylation, adenylation, or phosphorylation . Gentamicin uptake in two tested strains was significantly reduced, compared to that of gentamicin-sensitive E . coli (MIC, 0.5 microgram/mL) . These strains are likely resistant due to a relative reduction of the amount of gentamicin and other aminoglycosides entering the bacterial cell . Two strains showed evidence of adenyltransferase ANT(2")-I activity.

Mol Gen Mikrobiol Virusol, 1998, (3), 22 - 6
{Study of antigenic determinants of Yersinia pestis lipopolysaccharide using monoclonal antibodies}; Fedorova VA et al.; Species- and genus-specific antigenic determinants of total serological activity of plague agent lipopolysaccharide (LPS) were detected for the first time with a panel of monoclonal antibodies (MAb) in Y . pestis core polysaccharide in the R-form . MAb specifically bind radicals on one or several monosaccharides of core LPS . Galactose, fucose, and mannose contain common antigenic determinants for enterobacteria; glucosamine, glucose, ribose, xylose, and 2-ketodeoxyoctanoic acid (KDO) contain determinants for Y . pestis and Y . pseudotuberculosis; and epitopes differentiating the two latter agents by the carbohydrate component are localized on glucosamine, mannose, xylose, and KDO . Epitopes common for the Enterobacteriaceae family and species-specific epitopes, two of which are identic to core polysaccharide radicals, are situated on Y . pestis lipid A.

J Infect, 1998 May, 36(3), 279 - 85
The molecular and clinical epidemiology of enterobacteriaceae-producing extended-spectrum beta-lactamase in a tertiary care hospital; D'Agata E et al.; To describe the epidemiology of Enterobacteriaceae-producing extended-spectrum beta-lactamase (EP-ESBL) in a non-outbreak setting, and to define the risk factors associated with colonization, a 5-month surveillance study was initiated . Ten of 333 patients were colonized with EP-ESBL, as defined by isoelectric focusing . Klebsiella sp . and Escherichia coli were the species most commonly harbouring these plasmid-mediated enzymes . Of the 16 SHV-producing isolates, 10 were SHV-3-like (pI 7.0) and six were SHV-5-like (pI 8.2) . All isolates were resistant to ceftriaxone . Ceftazidime resistance was detected in 50% and 100% of SHV-3-like and SHV-5-like producing isolates, respectively . One patient was colonized with four different SHV-5-like producing Enterobacteriaceae . These isolates carried plasmids that were indistinguishable by restriction endonuclease analysis, indicating broad plasmid transfer within the patient . By logistic regression, haemodialysis was a strong risk factor for colonization with EP-ESBL, suggesting that, in our hospital, horizontal transmission is an important mechanism of dissemination of these resistant pathogens.

Microb Pathog, 1998 Oct, 25(4), 189 - 96
Shigella infection as observed in the experimentally inoculated domestic pig, Sus scrofa domestica; Maurelli AT et al.; The domestic pig, Sus scrofa domestica, was investigated as a potential animal model for shigellosis . We examined the effects of pig age, pig breed and antibiotic pretreatment upon Shigella infection . Shigella dysenteriae, and Shigella flexneri (both virulent and avirulent strains) were utilized . Our results indicated that young (4-week-old), conventionally re ared, domestic pigs were routinely, but briefly, colonized (average=3.5+/-2.5 days) following oral or gavage administration ofS . flexneri, as determined by direct rectal cultures . The duration of S . dysenteriae colonization was significantly shorter . Inoculation of younger (2 days) or older (9 weeks) pigs with S . flexneri had no significant effect on infection duration . Similarly, infection of 4-week-old pigs with virulent and avirulent strains of S . flexneri had no effect upon the duration of infection, nor did the use of a swine-passaged S . flexneri isolate . Marked clinical, histopathological (gross and microscopic) and immunoIhistopathological signs of disease were absent in all infections . However, in instances where microscopic histopathological evidence was used to correctly identify infected pigs, tonsillar lesions were the consistently noted criteria . The tonsils are believed to be an important portal of entry for Salmonella choleraesuis, another member of the Enterobacteriaceae and a prevalent pig pathogen . Taken altogether, our results indicate that the domestic pig is unsuitable as a model for shigellosis .

Scand J Infect Dis, 1998, 30(4), 411 - 6
The effects of the morphological response of Enterobacteriaceae to cephalosporins on PAE and CERT; Mackenzie FM et al.; PAE and CERT values of cefaclor, loracarbef and cefuroxime (0.1-100 x MIC) were established for 8 E . coli, 3 K . pneumoniae and 2 P . mirabilis isolates . Cell enumeration was by impedance (IMP) monitoring in combination with either bioluminescence (BIOL) or viable counting (VC) . Morphology was determined by interference contrast microscopy . After 2 h exposure to cefaclor, loracarbef and cefuroxime; concentration-dependent differences in counts were seen by BIOL and VC, varying from a mean value of 0.07 x log10 after exposing the P . mirabilis isolates to 0.1 x MIC cefaclor to a mean value of 2.24 x log10 after exposing the E . coli strains to 100 x MIC cefuroxime . Higher concentrations gave rise to fragile morphological forms including spheroplasts and lower concentrations to less fragile forms such as long bacilli . The longest PAE and CERT values were obtained after exposing the E . coli strains to 100 x MIC cefaclor with mean values of 4.07 and 4.87 h, respectively . Corresponding values were PAE and CERT values of 2.17 and 2.60 h for 100 x cefuroxime and 3.45 and 2.91 h for 100 x MIC loracarbef . By the Student's t-test, PAE values determined by IMP/BIOL and IMP/VC were found to be significantly different, whereas CERT values were found not to be significantly different . PAE and CERT are concentration dependent and vary with specific antibiotic/organism combinations.

Gig Sanit, 1998 Sep-Oct, (5), 25 - 30
{Sanitary and microbiological assessment of marketable fish of the Volga-Caspian Sea region}; Lartseva LV; Opportunistic microbes, such as aeromonads, enterobacteria, and pseudomonads, which are responsible for spoiling fish during its storage and processing and capable to initiate pathological processes of fishes are common in the Volga-Caspian Sea region . Investigations demonstrated that it is necessary to develop new procedures for processing fish products, to carry out studies on regulation of microbiological criteria for assessing fish quality . This makes it necessary to make a bacteriological control of fish at all stages of its production.

West Afr J Med, 1998 Jul-Sep, 17(3), 136 - 9
Bacteria causing septicaemia in neonates with tetanus; Egri-Okwaji MT et al.; 105 consecutively admitted neonates with tetanus were screened for sepsis to determine the prevalence of sepsis in neonatal Tetanus (NNT) patients and identify the bacterial pathogens causing septicaemia in them . The presence of omphalitis, poor colour, hypothermia and hyperthermia were found to be sensitive predictors of septicaemia in NNT patients . 50 bacterial pathogens were isolated from 50 babies . Klebsiella pneumoniae (20.7%), and Enterobacter cloacae (19.0%) were the leading gram negatives, while staphylococcus aureus (19.2%) was the prevalent gram positive organism isolated . Antimicrobial susceptibility profile heavily favours ofloxacin but a combination of cloxacillin and gentamicin is recommended as first line . Ceftazidime with about 60% susceptibility across board is the favoured cephalosporin.

J Bacteriol, 1998 Nov, 180(22), 5875 - 84
Accumulation of the enterobacterial common antigen lipid II biosynthetic intermediate stimulates degP transcription in Escherichia coli; Danese PN et al.; In Escherichia coli, transcription of the degP locus, which encodes a heat-shock-inducible periplasmic protease, is controlled by two parallel signal transduction systems that each monitor extracytoplasmic protein physiology . For example, the heat-shock-inducible sigma factor, sigmaE, controls degP transcription in response to the overproduction and folded state of various extracytoplasmic proteins . Similarly, the CpxA/R two-component signal transduction system increases degP transcription in response to the overproduction of a variety of extracytoplasmic proteins . Since degP transcription is attuned to the physiology of extracytoplasmic proteins, we were interested in identifying negative transcriptional regulators of degP . To this end, we screened for null mutations that increased transcription from a strain containing a degP-lacZ reporter fusion . Through this approach, we identified null mutations in the wecE, rmlAECA, and wecF loci that increase degP transcription . Interestingly, each of these loci is responsible for synthesis of the enterobacterial common antigen (ECA), a glycolipid situated on the outer leaflet of the outer membrane of members of the family Enterobacteriaceae . However, these null mutations do not stimulate degP transcription by eliminating ECA biosynthesis . Rather, the wecE, rmlAECA, and wecF null mutations each impede the same step in ECA biosynthesis, and it is the accumulation of the ECA biosynthetic intermediate, lipid II, that causes the observed perturbations . For example, the lipid II-accumulating mutant strains each (i) confer upon E . coli a sensitivity to bile salts, (ii) confer a sensitivity to the synthesis of the outer membrane protein LamB, and (iii) stimulate both the Cpx pathway and sigmaE activity . These phenotypes suggest that the accumulation of lipid II perturbs the structure of the bacterial outer membrane . Furthermore, these results underscore the notion that although the Cpx and sigmaE systems function in parallel to regulate degP transcription, they can be simultaneously activated by the same perturbation.

Eur J Pediatr, 1998 Oct, 157(10), 843 - 5
Ciprofloxacin in preterm neonates: case report and review of the literature; van den Oever HL et al.; We report the use of ciprofloxacin in a preterm boy suffering from an invasive multiple resistant Enterobacter cloacae infection . The treatment was effective, after other antibiotics failed, and no adverse effects were observed during 3 years of follow up . The literature on compassionate ciprofloxacin use in 28 preterm or low birth weight infants is reviewed . Ciprofloxacin has been used to treat neonatal pneumonia, meningitis and septicaemia and was effective in all cases . Side-effects were limited to dental dyschromia and one observation on the emergence of resistance . Pharmacokinetics of ciprofloxacin were studied in seven preterm infants; iv doses ranging from 4 to 40 mg/kg per day revealed adequate serum peak concentrations (0.98-5.7 mg/l) but trough-peak ratios were high (median ratio: 32%), suggesting slower elimination in preterm infants as compared to older children . CSF concentrations were 0.10-1.45 mg/l . CONCLUSION: Ciprofloxacin treatment of preterm or low birth weight infants may be effective and without severe side effects in infections with bacteria resistant to other antibiotics

J Zoo Wildl Med, 1998 Sep, 29(3), 288 - 94
Antimicrobial susceptibility of bacteria isolated from pinnipeds stranded in central and northern California; Johnson SP et al.; Over a 2-yr period (1994-1995), the antimicrobial susceptibilities of 129 bacterial isolates recovered from live stranded California sea lions (Zalophus californianus), harbor seals (Phoca vitulina), and northern elephant seals (Mirounga angustirostris) were studied . Nineteen genera of bacteria were isolated from various sites of inflammation; abscesses and umbilici were the most common sites . Seventy-two percent of the bacterial isolated were gram negative, and the Enterobacteriaceae (Escherichia coli, Proteus spp., Klebsiella spp., Salmonella spp.) accounted for 75% of the gram-negative isolates . All of the gram-positive isolates were either Enterococcus spp . or Staphylococcus aureus . Multiple drug resistance was present in all but one of the bacterial isolates . The gram-positive bacteria were most susceptible to amoxicillin-clavulanic acid (77% of 36 isolates) and least susceptible to lincomycin (18% of 11 isolates) . The gram-negative bacteria were most susceptible to amikacin (91% of 91 isolates) and least susceptible to clindamycin (3% of 109 isolates).

Enferm Infecc Microbiol Clin, 1998 Aug-Sep, 16(7), 307 - 11
{Pyogenic hepatic abscesses: 16 years experience in its diagnosis and treatment}; Jimenez E et al.; BACKGROUND: The aim of the present was to know the epidemiologic characteristics and clinico-biological variables presented by pyogenic hepatic abscesses and to evaluate the different therapeutic alternatives with special emphasis on percutaneous drainage . METHODS: A historical retrospective review of the hepatic abscesses diagnosed and treated in the authors' hospital over a 16.5 year period was carried out . RESULTS: A total of 44 cases of pyogenic hepatic abscesses were collected representing a rate of 0.088% of the hospital admissions . The mean age of the patients was 61.8 years . Thirty-four percent were cryptogenetic, being followed in frequency by those of biliary, post abdominal surgery and venoportal origin . Fever and right hypochondrial pain were the most frequent clinical manifestations, accompanied by an elevation in VSG and leucocytosis being the most common analytical alterations . Ultrasonography and CAT were found to be valuable in the diagnosis and treatment . The microorganism responsible was identified in 48% of the cases, with enterobacteria being the greatest number isolated . Fifty-two percent of the abscesses were treated with percutaneous drainage (73% if only patients post 1984 are considered), with minimum complications and a reduction in the number of days of hospitalization in comparison with surgical treatment . CONCLUSIONS: The presentation of a pyogenic hepatic abscess may be unspecific . Imaging techniques (echography and CAT) provide the main support in both the diagnosis and treatment . Percutaneous drainage plus early empiric antibiotherapy are the treatment of choice in pyogenic hepatic abscesses.

APMIS, 1998 Sep, 106(9), 917 - 20
Correlation of in vitro susceptibility testing results for amoxicillin-clavulanate and ampicillin-sulbactam using a panel of beta-lactamase-producing Enterobacteriaceae; Siu LK et al.; Correlation between in vitro susceptibility results for amoxicillin-clavulanate (AMC) and ampicillin-sulbactam (SAM) was studied using 136 clinical and control strains of Enterobacteriaceae harboring TEM-1, SHV-1 or OXA-1-like beta-lactamases . Determination of minimal inhibitory concentration of antibiotics was performed by agar dilution . The beta-lactamases were initially characterized using isoelectric focusing . Further identification was done by DNA hybridization with or without prior PCR amplification . All strains sensitive to SAM were found to be sensitive also to AMC . In contrast, among those susceptible to AMC, only 50% were sensitive to SAM while 36% gave intermediate results and 14% were resistant . Major differences were found solely among SHV-producers while minor differences occurred mostly among TEM-producers . This phenomenon is probably related to the differential activities of clavulanate and sulbactam against various beta-lactamases . In conclusion, testing of Enterobacteriaceae isolates for susceptibility to AMC and SAM should be performed and reported individually to avoid erroneous designation of susceptibility.

Oral Microbiol Immunol, 1998 Oct, 13(5), 315 - 21
Antimicrobial susceptibility of oral isolates of Enterobacter cloacae and Klebsiella pneumoniae from a southern Chinese population; Sedgley CM et al.; The antibiotic susceptibilities of 59 Enterobacter cloacae and 39 Klebsiella pneumoniae human oral isolates collected from a southern Chinese population in Hong Kong were investigated for their susceptibility to eight antibiotics: ampicillin, cephalothin, cefuroxime, ceftazidime, ciprofloxacin, gentamicin, tetracycline and trimethoprim/sulfamethoxazole using the E-Test method for direct quantification of minimum inhibitory concentrations . Most strains were sensitive to all antibiotics except ampicillin and cephalothin . Ampicillin resistance was exhibited by 82% of K . pneumoniae and 69% of E . cloacae isolates . Eighty-eight percent of E . cloacae isolates were resistant to cephalothin . Several strains fell within the intermediate category of sensitivity for ampicillin (E . cloacae and K . pneumoniae), cefuroxime (E . cloacae) and tetracycline (K . pneumoniae) . Comparison with other Hong Kong data suggests that resistance rates to cefuroxime, ceftazidime, ciprofloxacin, gentamicin, tetracycline and trimethoprim/sulfamethoxazole exhibited by the oral isolates are generally lower than in enterobacters and Klebsiella spp . isolated from urine, skin and soft tissues in Hong Kong populations.

Biosci Biotechnol Biochem, 1998 Sep, 62(9), 1774 - 7
Molecular cloning, sequencing and characterization of the genes for adenosylcobalamin-dependent diol dehydratase of Klebsiella pneumoniae; Tobimatsu T et al.; Klebsiella pneumoniae and some of the other Enterobacteriaceae form both diol dehydratase and glycerol dehydratase in response to growth substrates . To compare these enzymes produced by the same bacterium, the pdd genes of K . pneumoniae encoding adenosylcobalamin-dependent diol dehydratase were cloned and sequenced . The sequential three open reading frames (pddA, pddB, and pddC genes) encoded polypeptides of 554, 228, and 174 amino acid residues with predicted molecular weights of 60,379(alpha), 24,401(beta), and 19,489(gamma), respectively . The deduced amino acid sequences of the subunits were 84-100% and 54-71% identical with those reported for diol dehydratases and glycerol dehydratases, respectively.

Biochim Biophys Acta, 1998 Nov 8, 1442(2-3), 148 - 60
The PecT repressor interacts with regulatory regions of pectate lyase genes in Erwinia chrysanthemi; Castillo A et al.; Erwinia chrysanthemi is a broad host range phytopathogenic enterobacterium responsible for soft-rot disease of many plant species . The pecT gene encodes a repressor that negatively regulates the expression of virulence factors, such as pectinases, motility or exopolysaccharide synthesis . The cloned pecT gene was overexpressed using a phage T7 system . The purification of PecT involved the use of a TSK-heparin column and delivered the PecT protein that was purified to near homogeneity . The purified repressor displayed a 34 kDa apparent molecular mass . Gel-filtration experiments revealed that the PecT protein is a dimer . Band-shift assays demonstrated that the tetramer of the PecT protein could specifically bind in vitro to the regulatory regions of the pectate lyase genes with variable affinities . In addition, we demonstrated that PecT represses its own synthesis by interacting independently with two 200 bp regions, R1 and R2, located from -382 to -632 and -17 to -234, respectively, from the distal P1 promoter and from -465 to -715 and -100 to -317 from the P2 proximal promoter . We propose a model that explains the regulation exerted by PecT on its target genes and that integrates the phenotype obtained with a PecT overproducing pec-1 mutant or a pecT mutant.

J Clin Pathol, 1998 Jul, 51(7), 537 - 8
Candida albicans blastoconidia in peripheral blood smears from non-neutropenic surgical patients; Berrouane Y et al.; An 80 year old woman developed fever 11 days after volvulus surgery . A peripheral blood smear showed numerous yeast cells--both extraleucocytic and intraleucocytic--as well as leucoagglutination . The fungal elements included blastospores, pseudohyphae, and germ tubes . Two days later, blood cultures yielded Candida albicans, Enterobacter aerogenes, and Staphlococcus aureus . The patient had no medical history of immunodeficiency . Several reports indicate that fungal elements may be detected in peripheral blood smears from patients who have a severe intestinal disease.

Appl Environ Microbiol, 1998 Nov, 64(11), 4317 - 20
Metal accumulation and vanadium-induced multidrug resistance by environmental isolates of Escherichia hermannii and Enterobacter cloacae; Hernandez A et al.; Contaminated soils from an oil refinery were screened for the presence of microorganisms capable of accumulating either nickel, vanadium, or both metals . Three strains of bacteria that belonged to the family Enterobacteriaceae were selected . Two of them were Escherichia hermannii strains, and outer membrane profile (OMP) analysis showed that they were similar to a strain of clinical origin; the other one was an Enterobacter cloacae strain that differed from clinical isolates . The selected bacteria accumulated both nickel and vanadium . Growth in the presence of vanadium induced multidrug resistance phenotypes in E . hermannii and E . cloacae . Incubation with this metal changed the OMP profile of E . hermannii but did not produce variations in the expression of the major OMPs of E . cloacae.

Appl Environ Microbiol, 1998 Nov, 64(11), 4276 - 82
Physiological diversity of the rhizosphere diazotroph assemblages of selected salt marsh grasses; Bagwell CE et al.; Rhizosphere diazotroph assemblages of salt marsh grasses are thought to be influenced by host plant species and by a number of porewater geochemical parameters . Several geochemical variables can adversely affect plant productivity and spatial distributions, resulting in strong zonation of plant species and growth forms . This geochemically induced stress may also influence the species compositions and distributions of rhizosphere diazotroph assemblages, but little is currently known about these organisms . The diversity and key physiological features of culturable, O2-tolerant rhizosphere diazotrophs associated with the tall and short growth forms of Spartina alterniflora and with Juncus roemerianus were examined . A total of 339 gram-negative strains were isolated by a root stab culture approach and morphologically and physiologically characterized by using API and BIOLOG tests . Eighty-six distinct groups composed of physiologically similar strains were identified . Of these groups, 72% were shown to be capable of N2 fixation through molecular analyses, and a representative strain was chosen from each diazotroph group for further characterization . Cluster and principal-components analysis of BIOLOG data allowed the designation of physiologically distinct strain groupings . Most of these groups were dominated by strains that were not identifiable to species on the basis of API or BIOLOG testing . Representatives of several families including the Enterobacteriaceae, Vibrionaceae, Azotobacteraceae, Spirillaceae, Pseudomonadaceae, and Rhizobiaceae were recovered, as well as strains with no clear taxonomic affiliations . This study identifies numerous potentially important physiological groups of the salt marsh diazotroph assemblage.

Eur J Clin Microbiol Infect Dis, 1998 Aug, 17(8), 566 - 9
Improved recovery of antibiotic-stressed microorganisms on inclusion of saponin in aerobic blood culture media; Elliott TS et al.; The recovery rates and times to detection of microorganisms isolated from two similar blood culture media, one containing saponin, were compared . A total of 2117 blood cultures were analysed in a prototype automated blood culture system . Significantly more gram-positive organisms (P<0.05) and gram-negative organisms (P<0.05), including Enterobacteriaceae (P<0.05) were recovered from the lytic medium . Average time to detection in the lytic medium was 15.8 h, compared to 22.7 h in the other medium (P<0.001) . The improved recovery of microorganisms was most pronounced in blood samples obtained from patients being treated with antibiotics at the time of venesection . In vitro experiments on antibiotic affected bacteria confirmed the protective effect of saponin.

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