Enterobacteriacea

Bratisl Lek Listy, 1996 Nov, 97(11), 675 - 9
Etiology of bacteraemia in patients with various malignancies: is there association between certain antineoplastic drugs and microorganism?
Balaz M, Demitrovicova A, Spanik S, Drgona L, Krupova I, Grausova S, Kral'ovicova K, Krchnakova A, Trupl J, Kunova A, Krcmery V Jr.
The authors studied a relationship between particular bacterial or fungal organisms isolated from blood cultures and type of malignancy and antineoplastic drugs in 237 cancer patients . Sixty four had acute myelogenous leukemia (AML), 43 non-Hodgkin's lymphoma (NHL) and 140 solid tumors (ST) . All patients had at least one positive blood cultures for one or more microorganism drawn during 1-10 days after cytotoxic chemotherapy, viridans streptococcal bacteremia was more frequently observed in patients with AML (12.5%) and NHL (27.9%) than ST (43%, p < 0.01 and 0.03) . The incidence of anaerobic bacteria was similar in patients with NHL and ST, and in both groups significantly higher (p < 0.05) than in AML . Enterobacteriaceae caused bacteremia less frequently in patients with AML than in those with ST (12.5 vs 27.8%, p < 0.05) . However, the highest incidence of Stenotrophomonas maltophilia bacteremia was seen in patients with AML (6.3% vs 2.3%, p < 0.04 and 0.03) . Concerning fungemia, Candida albicans occurred significantly more frequently in blood cultures in patients with NHL, and molds in patients with AML . Cytarabine and metothrexate seems to be more frequently associated with viridans streptococci, cytarabine and mitoxanthrone with Stenotrophomonas maltophilia, B . fragilis with cisplatin and 5-fluorouracil, Fusarium spp., Mucorales and Aspergillus spp . with acute leukaemia (AL) treated with cytarabine and mitoxantrone . The association of other pathogens with an underlying disease or chemotherapeutic regimen could not be documented . (Tab . 1, Ref . 19.).

Mikrobiologiia, 1996 Nov-Dec, 65(6), 763 - 7
{Comparative characterization of the physico-chemical properties of lipopolysaccharides of Yersinia pestis and R-mutants of enterobacteria}; Gremiakova TA et al.; Electrokinetic potentials (EKP) of the cells of R mutants of Escherichia coli and Salmonella minnesota and cells of Yersinia pestis strains EV (line NIIEG), 358/12 P-, TWJ, Java, and 231 (708) were determined, as well as EKP of lipopolysaccharide (LPS) preparations isolated from these bacteria . The electric characteristics of the cell surfaces of the strains under investigation were demonstrated to correlate with the LPS charge and the reduction extent of their molecules . Acidic hydrolysis of LPS on the cell surface resulted in the leveling of the distinctions in EKP values (their reduction to the same level) . EKP values and the size of LPS micelles of the studied Y . pestis strains corresponded to those of the deep R mutants of enterobacteria, while the aggregation extent of the molecules was higher for Y . pestis.

Dtsch Tierarztl Wochenschr, 1996 Nov, 103(11), 468 - 72
{Inhibition phenomena between Salmonella strains--a new aspect of salmonella infection control in poultry}; Martin G et al.; Freshly hatched chickens show a very high susceptibility to Salmonella infections and control measures are therefore frequently focused on the period shortly after hatching . Experimental investigations using one strain against itself, differentiated by different antibiotic resistance markers, have shown that colonisation with Salmonella prevents the establishment of subsequently inoculated challenge organisms in the chicken gut . The inhibition effect lasts for several days and is detectable even when a challenge dose of 10(8) organisms is used . It is dependent of the breed of bird . Chickens colonised with Salmonella shed a subsequently inoculated challenge strain with significant lower numbers for several weeks than do non colonised control birds . The phenomenon is strain specific but not serovarspecific as has been shown in investigations using different strains of the same and other serovars for colonisation and challenge . The phenomenon shows a large variability between strains . Using other Enterobacteriaceae strains comparable inhibition against Salmonella was not observed . One important topic for further investigation is the capability of Salmonella live vaccines given orally to establish a protection effect, based on the inhibition phenomenon in the first few days of live, developing into a long-lasting immunity when birds reach immunological maturity.

Plasmid, 1996 Nov, 36(3), 183 - 90
Characterization of the stable maintenance of the Shigella flexneri plasmid pHS-2; Rehel N et al.; pHS-2 is a 3-kb plasmid originally isolated from Shigella flexneri infections associated with reactive arthritis in humans . This plasmid is stably maintained in many clinical isolates of Shigella flexneri . The nucleotide sequence of this plasmid displays two closely linked regions that may play a role in the maintenance of this plasmid . One region consists of a 250-bp locus showing a significant homology to the ColE1 cer site . The results indicate that the cer-like site of pHS-2, like the ColE1 cer site, acts as a recA-independent, site-specific recombination site involved in the resolution of multimers, requiring the presence of the host-encoded factors ArgR, PepA, XerC, and XerD . The second region consists of a 36-kDa open reading frame involved in generating resistance to the bactericidal effect of complement, which confers a selective advantage to cells containing this sequence . The results also indicate that pHS-2 can replicate in another species of Enterobacteriaceae (Escherichia coli) and is mobilized by the F plasmid.

Microbiology, 1996 Nov, 142 ( Pt 11), 2995 - 3004
The Bacillus subtilis genes for ribonucleotide reductase are similar to the genes for the second class I NrdE/NrdF enzymes of Enterobacteriaceae; Scotti C et al.; We have cloned and sequenced the nrd (nucleotide reductase) locus of Bacillus subtilis . The locus seems to be organized in an operon comprising four ORFs . The first three encode polypeptides highly similar to the product of the coding sequences characterizing the nrdEF operons of Enterobacteriaceae . The sequencing of the conditional lethal mutation ts-A13, localized in the nrdE cistron, and the lethality of insertional mutations targeted in the internal region of nrdE and nrdF, demonstrated the essential role of this locus . The fourth ORF, ymaB, part of the putative operon, which is not similar to any known protein, is also essential . The regulation of expression of the operon, monitored by lacZ transcriptional fusions, is similar to the regulation of the functionally relevant nrdAB operon of Escherichia coli . The operon was induced by thymidine starvation and its expression was directly or indirectly affected by RecA function . Genetic and functional analysis strongly indicates that in B . subtilis the class I ribonucleotide reductase encoded by this nrd operon is evolutionarily distant from the homologous class I enzyme of Enterobacteria.

J Med Entomol, 1996 Nov, 33(6), 983 - 7
Reservoir competence of Alphitobius diaperinus (Coleoptera:Tenebrionidae) for Escherichia coli (Eubacteriales:Enterobacteriaceae); McAllister JC et al.; Larval and adult lesser mealworms, Alphitobius diaperinus (Panzer), were found to harbor a Congo red-binding strain of Escherichia coli (Migula) Castellani & Chalmers both on the external surface of their body and internally for 12 d . Thereafter, E . coli was not detected, even though the beetles were exposed continuously to a food source inoculated with the bacteria . Lesser mealworm larvae and adults discharge E . coli bacteria in their feces for up to 6 and 10 d, respectively . However, bacteria were no longer detected in their feces after larvae underwent a single molt to the next larval stage . This indicated there was no transstadial transmission of this strain of E . coli . Consumed infected larvae were found to cause more 1-d-old chicks to have positive cloacal swabs for Congo red-binding E . coli than consumed infected adults . The data indicated that the lesser mealworm may play a role in the direct transmission of E . coli and contribute to the spread of this bacteria in broiler production systems . This may be achieved by beetles being directly consumed by chickens or indirectly by spread of the bacteria throughout the broiler house by lesser mealworm feces.

Microb Pathog, 1996 Nov, 21(5), 307 - 18
Monoclonal antibodies against Haemophilus influenzae lipopolysaccharides: clone MAHI 4 binding to a pentasaccharide containing terminal beta-Gal residues and clone MAHI 10 recognizing terminal phosphorylated saccharide residues; Borrelli S et al.; Mouse monoclonal antibodies MAHI 4 and MAHI 10 reactive with Haemophilus influenzae lipopolysaccharide (LPS), were generated by fusing mouse myeloma cells with spleen cells of mice immunized with H . influenzae strain RM.7004-XP-1 . The antibody MAHI 4 reacted in whole-cell enzyme immunoassay (EIA) and colony-dot-immunoblotting with 20 of 123 H . influenzae strains and to a few other human Haemophilus spp . and Neisseria spp., but not to any Bordetella pertussis, B . parapertussis, Aeromonas spp . or Moraxella catarrhalis strains tested . This suggests a specific epitope accessible to recognition in just a few strains . This conclusion was supported by the data on binding of MAHI 4 to only three of 18 H . influenzae LPSs tested, but not to any Haemophilus ducreyi or enterobacterial LPSs . The antibody MAHI 10 bound to 80 of 123 strains of H . influenzae and to a few strains of Neisseria spp . and M . catarrhalis as evaluated by EIA and colony-dot-immunoblotting, which suggests an epitope accessible to recognition in 65% of the H . influenzae strains tested . The antibody MAHI 10 reacted with 10 of 18 H . influenzae LPSs as determined by EIA . By using polysaccharides, obtained after both mild acidic hydrolysis, strong alkali treatment, and dephosphorylation, as inhibitors of the antibodies binding to H . influenzae LPS antigens it was shown that phosphate groups were essential for the binding of MAHI 10 to LPS but they did not affect antigenic recognition by MAHI 4 . None of the monoclonal antibodies bound to isolated lipid A, but the aggregation caused by the fatty acids of lipid A was essential for optimum epitope recognition . Enzymatic treatment of homologous LPSs with galactose-oxidase led to products which were between 20 to 30 times less effective as inhibitors of the binding of the MAHI 4 than the native LPSs . Taken together the results indicate that MAHI 4 has the following pentasaccharide as the epitope Gal beta 1-->2 Hep alpha 1-->2Hep alpha 1-->3Hep alpha 1--> Kdo(P) . These results emphasize the importance of the terminal beta-Gal residue in the definition of the MAHI 4 specificity, and of the terminal phosphorylated saccharide residues of some of the Haemophilus LPSs for the MAHI 10 specificity.

Transfusion, 1996 Nov-Dec, 36(11-12), 989 - 93
Evaluation of swirling, pH, and glucose tests for the detection of bacterial contamination in platelet concentrates; Wagner SJ et al.; BACKGROUND: Although infrequent, episodes of transfusion-associated bacterial sepsis may lead to serious outcomes or death and therefore are of concern . This study evaluates the sensitivity of three surrogate tests for the presence of bacteria in platelet concentrates: cessation of swirling, low extracellular pH, and low plasma glucose levels . STUDY DESIGN AND METHODS: Day 0 platelet concentrates were inoculated with low levels of one of seven bacterial strains and stored with agitation at 20 to 24 degrees C for up to 5 days . In the morning and afternoon of each day of storage, bacterial levels were ascertained by quantitative plate culture, and platelet concentrates were tested for platelet pH, plasma glucose, and swirling . Quantitative and semiquantitative dipstick techniques were used to determine pH and glucose levels . RESULTS: Platelet concentrates had attained stationary phase growth of Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Bacillus cereus, Enterobacter cloacae, Streptococcus mitis, or Staphylococcus epidermidis (> or = 10(7) -10(8) colony-forming units {CFU}/mL) before either the swirling or dipstick methods suggested the presence of bacteria . The sensitivity of swirling and glucose tests for detecting bacterial contamination in platelet concentrates was generally comparable . Although the sensitivity of the pH test was generally similar to that of swirling and glucose tests for most bacteria, platelet concentrates contaminated with E . cloacae had normal pH despite the presence of high levels of bacteria (> or = 10(7)-10(8) CFU/mL) . CONCLUSION: The sensitivity in detection of bacteria in platelet concentrates by the swirling technique or by measuring extracellular pH or plasma glucose is less than the sensitivity reported for microscopy with Gram stain (10(5)-10(6) CFU/mL), fluorescence microscopy with acridine orange stain (10(4)-10(5) CFU/mL), chemiluminescence detection of ribosomal RNA (10(3)-10(4) CFU/mL), and automated bacterial culture (1 CFU/sample volume).

J Bacteriol, 1996 Nov, 178(22), 6623 - 7
Sequence and properties of pentaerythritol tetranitrate reductase from Enterobacter cloacae PB2; French CE et al.; Pentaerythritol tetranitrate reductase, which reductively liberates nitrite from nitrate esters, is related to old yellow enzyme . Pentaerythritol tetranitrate reductase follows a ping-pong mechanism with competitive substrate inhibition by NADPH, is strongly inhibited by steroids, and is capable of reducing the unsaturated bond of 2-cyclohexen-1-one.

Am J Gastroenterol, 1996 Nov, 91(11), 2399 - 405
Bacteriological method for detecting small intestinal hypomotility; Riordan SM et al.; OBJECTIVE: Small intestinal hypomotility is an important cause of small intestinal bacterial overgrowth, yet assessment of small intestinal motility in this setting is problematic . This study was performed to investigate the validity of a bacteriological method for detecting small intestinal hypomotility . METHODS: Twenty-five subjects without previous gastric surgery were studied with (i) concurrent bacteriological analyses of fasting saliva and gastric and proximal small intestinal aspirates, (ii) measurement of gastric pH, and (iii) scintigraphic assessment of small intestinal transit rates of a liquid test meal . The reproducibility of bacteriological analyses of saliva and small intestinal secretions was determined in 12 subjects . RESULTS: Serial bacteriological analyses of saliva and proximal small intestinal secretions yielded reproducible results over time periods of up to 1 month . Eleven subjects were deemed to harbor Enterobacteriaceae of nonsalivary origin in proximal small intestinal secretions . Orocaecal transit, but not gastric emptying, of a liquid test meal was significantly delayed in this group (p = 0.002 and p = 0.84, respectively), suggesting the presence of small intestinal hypomotility . Impaired gastric acidity unlikely confounded assessment of the origin of small intestinal Enterobacteriaceae in any instance . CONCLUSIONS: The presence of Enterobacteriaceae of nonsalivary origin in proximal small intestinal secretions may be taken to reflect the presence of small intestinal hypomotility . The presence of impaired gastric acidity does not confound this approach . Because small intestinal intubation and culture of aspirate are required anyway to accurately diagnose small intestinal bacterial overgrowth, the simple addition of concurrent bacteriological analysis of saliva may allow small intestinal hypomotility to be detected at the same time as the presence or absence of small intestinal bacterial overgrowth itself is established, thus streamlining the investigation of subjects for this disorder and its possible causes.

J Hosp Infect, 1996 Nov, 34(3), 211 - 6
Enterobacter sepsis in the newborn--a growing problem in Karachi; Bhutta ZA; Enterobacter sepsis is commonly recognized as a hospital-acquired infection in childhood . In a five year prospective surveillance of neonatal sepsis at the Aga Khan University Hospital in Karachi, we identified Enterobacter sepsis in 28/292 (10%) cases, with an incidence of 0.7 per thousand births among inborn infants . There was no significant difference in predisposing factors and clinical features between Enterobacter and other infections . Approximately half (47%) of Enterobacter infections presented within 72 h of birth and the associated mortality was 21% . Increasing resistance to commonly used first- and second-line antibiotics over the last five years was noted . Enterobacter infections are emerging as significant pathogens among cases of neonatal sepsis in Karachi.

J Med Microbiol, 1996 Nov, 45(5), 359 - 65
Epidemiological investigation of Pseudomonas aeruginosa nosocomial bacteraemia isolates by PCR-based DNA fingerprinting analysis; Liu Y et al.; Between July 1994 and March 1995, 64 isolates of Pseudomonas aeruginosa were implicated in bacteraemia in 25 cancer patients in five wards of two hospitals . These, together with 24 environmental isolates and one isolate from a bacteraemia in a non-cancer patient were examined by three PCR-based DNA fingerprinting methods: random amplified polymorphic DNA (RAPD), enterobacterial-repetitive intergenic consensus (ERIC)-PCR, and 16S-23S spacer region-based RAPD . These methods were reproducible, discriminatory and showed close agreement; all indicated that 47 isolates that had caused bacteraemia in 19 cancer patients were indistinguishable . Seventeen other isolates that had caused bacteraemia in 10 cancer patients were discriminated into eight further groups, and the 24 environmental and non-cancer patient isolates into further distinct groups . No environmental source of the epidemic strain was found, but it was suspected that the outbreak was related to infusion implants.

Int J Food Microbiol, 1996 Nov, 33(1), 139 - 55
Specific spoilage organisms in breweries and laboratory media for their detection; Jespersen L et al.; The Gram positive bacteria are generally regarded as the most hazardous beer spoilage organisms in modern breweries, especially the lactobacilli: L . brevis, L . lindneri, L . curvatus, L . casei, L . buchneri, L . coryneformis, L . plantarum, L . brevisimilis, L . malefermentans and L . parabuchneri and the pediococci: P damnosus, P . inopinatus and P . dextrinicus . Micrococcus kristinae is the only species within the micrococci relevant to brewing . The Gram negative strictly anaerobic bacteria are apparently increasing in importance and include Pectinatus cerevisiiphilus, Pectinatus frisingensis and Selenomonas lacticifex, reported as obligate beer spoilage organisms: Zymophilus raffinosivorans as a potential beer spoilage organism; Megasphaera cerevisiae as an obligate spoilage organism of low alcohol beer and Zymomonas mobilis as capable of spoiling primed beer . With improved process technology the importance of aerobic bacteria has decreased and the same applies for the Gram negative aerobic bacteria Hafnia protea and Enterobacter cloacae which are capable of surviving beer fermentation . Beer spoilage organisms include several so-called wild yeasts, of which Saccharomyces species are generally considered the most important . Even though the detection of beer spoilage organisms by cultivation in laboratory media does not always provide the specificity and the sensitivity required, the use of selective media and incubation conditions still appears to be the method preferred by breweries . The media used depend on the type of sample, the specificity required and, for detection of wild yeasts, to some extent, the characteristics of the culture yeast . Among the media reported so far no single medium can be used to detect all members within a group of specific beer spoilage organisms and further work on the development of improved substrates are required both for bacteria and wild yeasts.

Int J Food Microbiol, 1996 Nov, 33(1), 103 - 20
Bacterial spoilage of meat and cured meat products; Borch E et al.; The influence of environmental factors (product composition and storage conditions) on the selection, growth rate and metabolic activity of the bacterial flora is presented for meat (pork and beef) and cooked, cured meat products . The predominant bacteria associated with spoilage of refrigerated beef and pork, are Brochothrix thermosphacta, Carnobacterium spp., Enterobacteriaceae, Lactobacillus spp., Leuconostoc spp., Pseudomonas spp . and Shewanella putrefaciens . The main defects in meat are off-odours and off-flavours, but discolouration and gas production also occur . Bacteria associated with the spoilage of refrigerated meat products, causing defects such as sour off-flavours, discolouration, gas production, slime production and decrease in pH, consist of B . thermosphacta, Carnobacterium spp . Luctobacillus spp . Leuconostoc spp . and Weissella spp . Analysis of spoilage as measured by bacterial and chemical indicators is discussed . It is concluded that a multivariate approach based on spectra of chemical compounds, may be helpful in order to analyse spoilage, at least for spoilage caused by lactic acid bacteria . The consequences of bacteria bacteria interactions should be evaluated more.

South Med J, 1996 Nov, 89(11), 1095 - 6
Gas gangrene of the arm due to Enterobacter cloacae in a neutropenic patient; Fata F et al.; Gas gangrene is a life-threatening emergency . Most cases are caused by clostridial infections, but nonclostridial causes are being increasingly recognized . Nonclostridial gas gangrene is most often due to polymicrobial organisms . Early diagnosis and therapy are required, since the disease may rapidly progress to fatal toxemia . We report a case of gangrenous, atraumatic, nonclostridial myonecrosis of the arm due to Enterobacter cloacae in a nondiabetic patient with neutropenia.

Appl Environ Microbiol, 1996 Nov, 62(11), 4121 - 8
Cloning and characterization of a locus encoding an indolepyruvate decarboxylase involved in indole-3-acetic acid synthesis in Erwinia herbicola; Brandl MT et al.; Erwinia herbicola 299R synthesizes indole-3-acetic acid (IAA) primarily by the indole-3-pyruvic acid pathway . A gene involved in the biosynthesis of IAA was cloned from strain 299R . This gene (ipdC) conferred the synthesis of indole-3-acetaldehyde and tryptophol upon Escherichia coli DH5 alpha in cultures supplemented with L-tryptophan . The deduced amino acid sequence of the gene product has high similarity to that of the indolepyruvate decarboxylase of Enterobacter cloacae . Regions within pyruvate decarboxylases of various fungal and plant species also exhibited considerable homology to portions of this gene . This gene therefore presumably encodes an indolepyruvate decarboxylase (IpdC) which catalyzes the conversion of indole-3-pyruvic acid to indole-3-acetaldehyde . Insertions of Tn3-spice within ipdC abolished the ability of strain 299R to synthesize indole-3-acetaldehyde and tryptophol and reduced its IAA production in tryptophan-supplemented minimal medium by approximately 10-fold, thus providing genetic evidence for the role of the indolepyruvate pathway in IAA synthesis in this strain . An ipdC probe hybridized strongly with the genomic DNA of all E . herbicola strains tested in Southern hybridization studies, suggesting that the indolepyruvate pathway is common in this species . Maximum parsimony analysis revealed that the ipdC gene is highly conserved within this group and that strains of diverse geographic origin were very similar with respect to ipdC.

J Clin Microbiol, 1996 Nov, 34(11), 2784 - 90
Epidemiological typing of isolates from an outbreak of infection with multidrug-resistant Enterobacter cloacae by repetitive extragenic palindromic unit b1-primed PCR and pulsed-field gel electrophoresis; Shi ZY et al.; An outbreak of multidrug-resistant Enterobacter cloacae infection lasted for 4 months in a neonatal intensive care unit (NICU) . Forty-six isolates from the NICU and 20 epidemiologically unrelated strains were characterized by pulsed-field gel electrophoresis (PFGE) and repetitive extragenic palindromic unit b1-primed PCR (REPUb1-PCR) typing . The PFGE patterns after XbaI restriction of the bacterial DNA were analyzed by computer software (Gelcompar) using the UPGMA (unweighted pair group method with arithmetic averages) clustering method and the Dice coefficient . The 46 isolates from the NICU were classified by PFGE typing into five clusters: A (further classified into 7 subtypes, A1 to A7), B, C, D, and E . This outbreak was attributed to multiple genetically related strains of cluster A which had a similarity of 85.8% +/- 4.6% . The minor band differences among strains of cluster A were probably due to minor genetic mutations . The type A1 and A3 strains were isolated from the clinical specimens of patients and hands of nurses . It was probable that these outbreak strains were transmitted among patients via the hands of personnel . REPUb1-PCR typing of the 46 isolates also demonstrated five types, in agreement with results obtained by the PFGE technique, but could not detect the minor mutations among the cluster A strains . Twenty epidemiologically unrelated strains were well distinguished by both PFGE and REPUb1-PCR typing . We conclude that PFGE is a highly discriminatory but time-consuming method for epidemiological typing of E . cloacae and that REPUb1-PCR is a more rapid method with good reproducibility and discriminatory power comparable to that of PFGE.

J Biomed Mater Res, 1996 Nov, 32(3), 473 - 9
Effect of calcium phosphate ceramics on gram-negative bacteria resistant to antibiotics; Opalchenova G et al.; This paper discusses the results of an experimental study on the effect of biphase calcium phosphate ceramics (BCPC) on laboratory-isolated polyresistant Gram-negative bacteria . Monitoring of this effect in a dynamical regimen was carried out upon Enterobacter cloacae 313, Klebsiella pneumoniae 227, Serratia marcescens 206, Klebsiella oxytoca 202, as well as on the standard strain Klebsiella pneumoniae 52145 (Institute Pasteur, Paris) . The results show a significant antimicrobial effect of the ceramics . Antimicrobial properties are manifested during direct contact with BCPC and these depend on the quantity and grain size of the particles, as well as on the microbiological characteristics of the test microorganisms, and particularly on their cell size.

J Infect Dis, 1996 Nov, 174(5), 1015 - 20
Characterization of a nosocomial outbreak involving an epidemic plasmid encoding for TEM-27 in Salmonella enterica subspecies enterica serotype Othmarschen; Morosini MI et al.; A ceftazidime-resistant Salmonella enterica subspecies enterica serotype Othmarschen strain, harboring the plasmid-mediated new extended-spectrum beta-lactamase TEM-27, was involved in a nosocomial outbreak (8 patients) at the Pediatric Cardiology Department of the Ramon y Cajal Hospital in Madrid . Genomic DNA polymorphism analysis, using an arbitrarily primed polymerase chain reaction, demonstrated the clonal nature of all Salmonella isolates . The plasmid encoding TEM-27 (pJMM1) was characterized by EcoRI, SacI, and BglI restriction . An identical restriction pattern was found in plasmid from all S . enterica strains . Possible in vivo intergeneric plasmid spread was suggested by the identification of an identical plasmid in Escherichia coli RYC5H and Enterobacter cloacae RYC39737 strains isolated during the outbreak . Results indicate that this outbreak involved dissemination of a single ceftazidime-resistant Salmonella strain and the spread of a single TEM-27-encoding plasmid among different Enterobacteriaceae.

Curr Microbiol, 1996 Nov, 33(5), 334 - 7
Isolation of Ewingella americana from the cultivated mushroom, Agaricus bisporus; Inglis PW et al.; The isolation of Ewingella americana, an unusual Enterobacteriaceae, is reported here for the first time in a non-animal reservoir . Thirty-five strains of E . americana have been recovered from the cultivated mushroom, Agaricus bisporus . The biochemical characteristics of these strains are consistent with previously published descriptions of this species recovered from clinical specimens and from molluscs . DNA reassociation analysis was used to confirm the identity of mushroom-derived E . americana, and restriction fragment length polymorphism was used to reliably differentiate strains that otherwise demonstrated little phenotypic variation.

J Biol Chem, 1996 Oct 25, 271(43), 26582 - 7
Allosteric regulation of the third ribonucleotide reductase (NrdEF enzyme) from enterobacteriaceae; Eliasson R et al.; Enterobacteriaceae contain genes for three separate ribonucleotide reductases: nrdAB code for a class Ia enzyme, active during aerobiosis, nrdDG for a class III enzyme, active during anaerobiosis, and nrdEF for a cryptic class Ib enzyme . The NrdEF enzyme provides the active reductase in other, widely different bacteria . Here, we describe the allosteric regulation of the Salmonella typhimurium NrdEF enzyme . It consists of two tightly bound homodimeric proteins, R1E and R2F . Nucleoside triphosphates (ATP, dATP, dGTP, and dTTP) regulate the substrate specificity by binding to a single site of the R1E protein (one nucleotide per polypeptide) . Regulation is similar to that of the NrdAB enzyme, with one major exception: dATP stimulates reduction of CDP (and UDP) under conditions when dATP strongly inhibits all activity of the NrdAB enzyme . The nrdA-coded R1 protein contains a second binding site for dATP (and ATP) that controls general enzyme activity . All known R1E proteins lack the 50 N-terminal amino acids of R1, and we propose that the activity site is located in this area of the protein . The more sophisticated regulation of NrdAB enzymes of eukaryotes provides protection against the possibly harmful overproduction of dNTPs.

Mutat Res, 1996 Oct 25, 357(1-2), 245 - 53
Identification of a DinB/UmuC homolog in the archeon Sulfolobus solfataricus; Kulaeva OI et al.; To date, eight closely related homologs of the Escherichia coli UmuC protein have been identified . All of these homologs appear to play critical roles in damage-inducible mutagenesis in enterobacteriaceae . Recently, a distantly related UmuC-homolog, DinB, has also been identified in E . coli . Using the polymerase chain reaction together with degenerate primers designed against conserved regions found in UmuC-like proteins, we have identified a new member of the UmuC-superfamily in the archeon Sulfolobus solfataricus . This new homolog shows high sequence similarity to DinB and a lower level of similarity to UmuC . As a consequence, we have called this new gene dbh (dinB homolog) . Analysis of approximately 2.7 kb DNA encompassing the dbh region revealed several open reading frames (orfs) . One, encoding a putative ribokinase, was located immediately upstream of dbh . This orf overlaps the dbh gene by 4 bp suggesting that both proteins might be coordinately expressed . Further upstream of the ribokinase-dbh locus was another orf encoding a potential ATPase homologous to two uncharacterized S . cerevisiae proteins (YD9346.02c and SC38KCXVI_20) and another E . coli DNA repair protein, RuvB . While this is the first report of a UmuC-like homolog in an archeon, we detected additional homologs using protein sequence comparisons in Gram-positive bacteria, cyanobacteria, and among potential human EST products, indicating that UmuC-related proteins comprise a ubiquitous superfamily of proteins probably involved in DNA repair and mutagenesis.

Microb Drug Resist, 1996 Fall, 2(3), 353 - 9
Emergence of resistance to beta-lactam agents in enterobacteriaceae species with group I beta-lactamases in Spain; Colom K et al.; The contribution of induction and stable derepression of chromosomal group I beta-lactamases to beta-lactam antibiotics resistance was studied in clinical isolates of Enterobacteriaceae, collected from patients treated with these antibiotics . Multiple isolates of the same species from the same patient were characterized by different typing methods . Sonicated extracts of cells were assayed for chromosomal and plasmid-mediated beta-lactamases by isoelectric focusing and cloxacillin inhibition studies . The specific beta-lactamase activity, basal and induced with cefoxitin, was determined to differentiate strains with inducible or derepressed production of the enzyme . Induction of beta-lactamases was performed in each strain against the beta-lactams used in the therapy of each patient . Older penicillins resulted in a moderate to strong increase in beta-lactamase activity, whereas the results obtained with first-generation cephalosporins were species dependent . Expanded-spectrum cephalosporins were weak inducers of beta-lactamases . Indeed, the use of cefotaxime for treatment preceded the appearance of strains that produced chromosomal group I beta-lactamases constitutively . These strains showed a remarkable reduction in sensitivity to ureidopenicillins, carboxipenicillins, expanded-spectrum cephalosporins, and monobactams, but not to carbapenems.

Lik Sprava, 1996 Oct-Dec, (10-12), 94 - 7
{The validation of empirical emergency antibacterial therapy in acute pyelonephritis}; Mitchenko MV; As many as 254 patients with acute pyelonephritis were evaluated for the whole range of possible inflammatory process pathogens with the aid of automatic microbiological system {symbol: see text} . Urine from the urinary bladder, renal pelves (as directed) was studied as was biopsy specimen of the kidney . Analysis of species range of the identified organisms showed Escherichia coli, Proteus, and mycoplasma, enterobacter, coccal flora and pseudomonads to be in 27.9%, 15.9%, 14.9%, 8.6%, and 5.5% respectively . Analysis of sensitivity of the discovered bacteria toward a wide range of antibacterial preparations permitted recommending for an urgent antiinflammatory therapy thienam, ophloxacin, cyprophloxacin, pephloxacin, norphloxacin, cephoxitin, and cephtriaxone . The form of the preparation (parenteral or peroral) will be prescribed depending upon the gravity of the course of acute pyelonephritis.

Z Lebensm Unters Forsch, 1996 Oct, 203(4), 326 - 32
Effects of modified atmosphere and vacuum packaging on the growth of spoilage and inoculated pathogenic bacteria on fresh poultry; Ozbas ZY et al.; Fresh chicken breast meats inoculated with Yersinia enterocolitica and Aeromonas hydrophila were packaged in glass jars either containing different compositions of modified atmospheres (MA) (100% CO2; 80% CO2/20% N2), or in vacuo or containing air, and were stored at 3 +/- 1 degrees C and 8 +/- 1 degrees C . The changes in gas composition as well as Y . enterocolitica, A . hydrophila, total aerobic bacterial, total psychotropic, Lactobacilli and Enterobacteriaceae counts were determined after 0, 1, 3, 7, 9, 11 and 14 days of storage . The results show that while the growth of Y . enterocolitica and A . hydrophila were retarded following MA storage, the pathogens were capable of growth in MA and vacuum storage at both temperatures, for the inoculation levels studied . For total aerobic bacterial counts, there were no differences between the values for chicken breast meats kept in different atmospheres . Being packaged in CO2 had the greatest inhibitory effect on the growth of psychotropic aerobic bacteria during the first 3 days . Lactic acid bacteria levels of samples stored in MA conditions and in vacuo increased rapidly when compared to those levels of samples stored in air . It was also found that the effect of MA storage increased at 3 +/- 1 degrees C.

Laryngorhinootologie, 1996 Oct, 75(10), 580 - 3
{Effect of postoperative endonasal mucous membrane care on nasal bacterial flora: prospective study of 2 irrigation methods with NaCl solution after paranasal sinus surgery}; Johannssen V et al.; BACKGROUND: Endonasal irrigation with saline solution is a widely used constituent of mucosal care after sinus surgery . This procedure could explain a repeatedly observed phenomenon: contamination of the endonasal mucosa by facultative skin pathogens from the palm during paranasal sinus irrigation . METHOD: For this reason the effect of nasal rinses with saline solution on the endonasal bacterial flora was investigated (use of so-called nasal douche {Siemens & Co., Bad Ems} compared to rinsing by hand) . In 36 patients (23 m., 13 f., 36 +/- 19.5 years of age) with chronic sinusitis, a total of 288 swabs was collected before, during, and after surgery . The collected specimens were transferred to a Port-A-Cul transport medium and processed within four hours . RESULTS: Two hundred sixty-six cultures of 325 bacterial strains were aerobic (82%), while 59 were anaerobic (18%) . Staphylococcus aureus (33%) and representatives of the Enterobacteriaceae family (31%) were the most common enriched germs . The number of times that enterobacteriaceae could be isolated was significantly (p < 0.05) lower (13%) when a nasal douche was used than when irrigation was done using the palm (38%) . An irrigation technique-related effect was found on neither the spectrum of the pathagonic organisms nor the wound healing process . CONCLUSION: The frequent isolation of enterobacteria in nasal swabs of individuals rinsing by hand constitutes the difference between irrigation by nasal douche and by hand in the postoperative care of the endonasal mucosa . These pathogens can sustain the paranasal sinus system.

APMIS, 1996 Oct, 104(10), 763 - 8
Aminoglycoside resistance mechanisms in Enterobacteriaceae and Pseudomonas spp . from two Danish hospitals: correlation with type of aminoglycoside used; Busch-Sorensen C et al.; Sixty-two aminoglycoside-resistant Gram-negative enteric bacteria were isolated over a 3-year period from two hospitals (Bispebjerg and Esbjerg) among a total of almost 270,000 isolates . These hospitals were selected because of their different aminoglycoside policies during the years investigated . At Bispebjerg Hospital the principal aminoglycoside used was tobramycin, while gentamicin was the first choice at Esbjerg Hospital . Escherichia coli was the most frequently found aminoglycoside-resistant species . Among the 61 aminoglycoside-resistant strains studied, resistance was due to aminoglycoside-modifying enzymes in all except two Xanthomonas maltophilia strains . The ANT(2") enzyme occurred significantly more often at Esbjerg Hospital (p = 0.001), while enzymes of the AAC(3) or AAC(6') moieties were more common, but not significantly so, at Bispebjerg Hospital . The phenotypic pattern of aminoglycoside resistance, as determined by disc diffusion, correlated 100% with the ANT(2") and AAC(3)-V (the two most common enzymes among the isolates) genotype of the organisms as established using DNA probes . Median minimum inhibitory concentrations (MICs) (mg/l) for clinically utilized aminoglycosides were: amikacin (1.6), gentamicin (25.0), kanamycin (50.0), netilmicin (1.6-25.0) and tobramycin (12.5-50.0) . Isolates from Bispebjerg Hospital revealed significantly higher MICs for netilmicin and tobramycin (p < 0.01) as compared to isolates from Esbjerg Hospital.

J Chemother, 1996 Oct, 8(5), 358 - 64
In vitro activity of meropenem against ciprofloxacin-resistant enterobacteriaceae and Pseudomonas aeruginosa; Garcia-Rodriguez JA et al.; The in-vitro susceptibilities of a total of 174 ciprofloxacin-resistant Enterobacteriaceae and Pseudomonas aeruginosa were determined . According to the BSAC and NCCLS breakpoints, meropenem, aztreonam, ceftibuten, ceftazidime, imipenem and cefotaxime were the most active (> 90%) antimicrobial agents tested against Enterobacteriaceae . Susceptibility of these strains to piperacillin/tazobactam, cefpodoxime and cefixime (84.96%) was higher than that to tobramycin, gentamicin and fosfomycin (50-75%) . More than 90% of P . aeruginosa were susceptible to meropenem when both interpretative susceptibility breakpoint criteria were used . Piperacillin, piperacillin/tazobactam and ceftazidime were active against 50-75% of the same strains . Meropenem was the most active antimicrobial tested against all ciprofloxacin-resistant clinical isolates assayed.

J Biochem (Tokyo), 1996 Oct, 120(4), 736 - 44
Gene cloning, purification, and characterization of NfsB, a minor oxygen-insensitive nitroreductase from Escherichia coli, similar in biochemical properties to FRase I, the major flavin reductase in Vibrio fischeri; Zenno S et al.; nfsB, encoding a minor oxygen-insensitive nitroreductase, was isolated by PCR using primers corresponding to two amino acid sequences conserved among the major flavin reductase from Vibrio fischeri and classical nitroreductases from Salmonella typhimurium and Enterobacter cloacae . The gene product, NfsB, was purified to homogeneity from extracts of Escherichia coli cells overexpressing it . NfsB was found to be situated at 13 min on the E . coli map . Biochemical analysis indicated NfsB to be a polypeptide having a calculated molecular weight of 23,904, capable of forming a homodimer and associated tightly with FMN as a prosthetic group . Although it exhibited a lower affinity to the NfsB apoenzyme than FMN, FAD could serve as an effective substitute for FMN . It was also shown that NfsB has a broad electron acceptor specificity and is associated with a low level of the NAD(P)H-flavin oxidoreductase . The NfsB catalysis obeys the ping pong Bi-Bi mechanism . The Km value for NADH varied depending on the second substrate used.

J Trop Pediatr, 1996 Oct, 42(5), 267 - 70
Neonatal meningitis in northern Jordan; Daoud AS et al.; A two-and-a-half year prospective study of neonatal meningitis in the two main referral hospitals in Northern Jordan was carried out to determine the clinical spectrum and particular characteristics of meningitis in the newborn . The 53 cases studied represented an incidence of 1.1 per 1000 live births . The commonest bacterial pathogen isolated was Klebsiella species (40 per cent) followed by Enterobacter (19 per cent) . The mortality rate and neurological sequelae among surviving children were 32 and 39 per cent, respectively, with higher rates among preterm/low birth weight and early onset meningitis groups . Of the presenting clinical features, there was a highly positive association between two risk factors and outcome . A bulging anterior fontanelle was the only significant predictor of mortality (P = 0.009) and altered sensorium was the only predictive of post-meningitis sequelae (P = 0.016) . The need to recognize that Klebsiella species is an increasingly important pathogen; cefotaxime or ceftazidime plus ampicillin are the most appropriate antibiotics to be used initially, and continuous surveillance thereafter have been stressed.

J Periodontol, 1996 Oct, 67(10 Suppl), 1114 - 22
Relationships between periodontal disease and bacterial pneumonia; Scannapieco FA et al.; Bacterial pneumonia is a prevalent and costly infection that is a significant cause of morbidity and mortality in patients of all ages . The continuing emergence of antibiotic-resistant bacteria (e.g., penicillin-resistant pneumococci) suggests that bacterial pneumonia will assume increasing importance in the coming years . Thus, knowledge of the pathogenesis of, and risk factors for, bacterial pneumonia is critical to the development of strategies for prevention and treatment of these infections . Bacterial pneumonia in adults is the result of aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which multiply in the lung and cause infection . It is recognized that community-acquired pneumonia and lung abscesses can be the result of infection by anaerobic bacteria; dental plaque would seem to be a logical source of these bacteria, especially in patients with periodontal disease . It is also possible that patients with high risk for pneumonia, such as hospitalized patients and nursing home residents, are likely to pay less attention to personal hygiene than healthy patients . One important dimension of this personal neglect may be diminished attention to oral hygiene . Poor oral hygiene and periodontal disease may promote oropharyngeal colonization by potential respiratory pathogens (PRPs) including Enterobacteriaceae (Klebsiella pneumoniae, Escherichia coli, Enterobacter species, etc.), Pseudomonas aeruginosa, and Staphylococcus aureus . This paper provides the rationale for the development of this hypothesis especially as it pertains to mechanically ventilated intensive care unit patients and nursing home residents, two patient groups with a high risk for bacterial pneumonia.

Clin Infect Dis, 1996 Oct, 23(4), 779 - 84
Antimicrobial resistance rates among aerobic gram-negative bacilli recovered from patients in intensive care units: evaluation of a national postmarketing surveillance program; Itokazu GS et al.; We assessed the rates of antimicrobial resistance between 1990 and 1993 in intensive care units in the United States . A standardized microtiter minimal inhibitory concentration panel was used to test approximately 100 consecutive gram-negative aerobic isolates that were recovered primarily from blood, wounds, urine, and pulmonary sites in patients treated in each of 396 intensive care units in 45 states . Amikacin and imipenem were the agents most active against the 33,869 nonduplicate isolates (those recovered only once) tested . Resistance of aerobic gram-negative bacilli to third-generation cephalosporins was found to be an emerging problem . Increases in rates of resistance to ceftazidime among isolates of Klebsiella pneumoniae (from 3.6% to 14.4%; P << .01) and Enterobacter species (from 30.8% to 38.3%; P = .0004) were noted from 1990 to 1993; rates of resistance among Pseudomonas aeruginosa isolates remained stable . Ceftazidime-resistant bacteria were frequently resistant to aminoglycosides and ciprofloxacin . Risk factors for ceftazidime resistance included the number of beds in the hospital, the teaching status of the hospital, and specific body sites from which the isolates were recovered.

Antimicrob Agents Chemother, 1996 Oct, 40(10), 2276 - 9
Plasmid-mediated formaldehyde resistance in Escherichia coli: characterization of resistance gene; Kummerle N et al.; The formaldehyde resistance mechanisms in the formaldehyde-resistant strain Escherichia coli VU3695 were investigated . A large (4.6-kb) plasmid DNA fragment encompassing the formaldehyde resistance gene was sequenced . A single 1,107-bp open reading frame encoding a glutathione- and NAD-dependent formaldehyde dehydrogenase was identified and sequenced, and the enzyme was expressed in an in vitro assay and purified . Amino acid sequence homology studies showed 62.4 to 63.2% identity with class III alcohol dehydrogenases isolated from horse, human, and rat livers . We demonstrated that the resistance mechanism in the formaldehyde-resistant strain E . coli VU3695 and in other formaldehyde-resistant members of the family Enterobacteriaceae is based on the enzymatic degradation of formaldehyde by a formaldehyde dehydrogenase.

Int J Syst Bacteriol, 1996 Oct, 46(4), 1034 - 41
Phenotypic and DNA relatedness between nematode symbionts and clinical strains of the genus Photorhabdus (Enterobacteriaceae); Akhurst RJ et al.; Bacterial strains isolated from wide ranges of nematode hosts and geographic sources and strains isolated from human clinical specimens were used to assess the taxonomic structure of the genus Photorhabdus . The following two methods were used: DNA relatedness and phenotypic characterization . Analysis of the DNA relatedness data revealed that all of the strains studied were congeneric and that the genus Photorhabdus is, on the basis of DNA relatedness data, more homogeneous than the other genus of nematode-symbiotic bacteria, the genus Xenorhabdus . In contrast to previous reports, only two DNA relatedness groups were identified in the genus Photorhabdus . These groups corresponded to the symbiotic strains and the clinical strains . There appeared to be some subgroups within the symbiotic strain group on the basis of the interactions of the strains with nematodes, which corresponded to some extent with the DNA relatedness data . However, there were significant ambiguities in the DNA relatedness data, and this group could not be subdivided on the basis of DNA relatedness data or phenotypic data . The distinct functional differences within and between the DNA relatedness groups of symbiotic Photorhabdus strains indicated that there are biologically significant sub-groups within the genus Photorhabdus that cannot be defined at this time . Further investigation of the taxonomy of Photorhabdus by using different approaches and a suitably wide range of strains is recommended . However, it is clear that the clinical strains form a recognizable subgroup within the genus even though no formal subtaxon can be defined at this time.

FEMS Microbiol Lett, 1996 Oct 1, 143(2-3), 127 - 32
Comparative DNA analysis of Bordetella pertussis clinical isolates by pulsed-field gel electrophoresis, randomly amplified polymorphism DNA, and ERIC polymerase chain reaction; Moissenet D et al.; We used DNA fingerprinting by pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD) and PCR amplification of enterobacterial repetitive intergenic consensus sequences (ERIC-PCR) to compare 15 clinical isolates of Bordetella pertussis recovered between August 1993 and September 1995 from 13 infants and two adults, living in the same geographic area . PFGE produced 10 patterns and made it possible to differentiate all the isolates and to indicate an intrafamilial transmission . RAPD and ERIC-PCR generated banding patterns with small differences and had a poor discriminatory power . During the last 2 years, at Armand-Troussau pediatric hospital, 10 distinct clones of clinical B . pertussis isolates, with a predominant clone including seven strains, could be determined by the PFGE method.

Appl Environ Microbiol, 1996 Oct, 62(10), 3868 - 70
Evaluation of cyclohexenoesculetin-beta-D-galactoside and 8-hydroxyquinoline-beta-D-galactoside as substrates for the detection of beta-galactosidase; James AL et al.; We describe the synthesis of two new substrates for the detection of beta-galactosidase and evaluate their performance in comparison with that of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) . Of 171 Enterobacteriaceae strains that were able to hydrolyze X-Gal, 166 (97.1%) also hydrolyzed cyclohexenoesculetin-beta-D-galactoside whereas only 96 (56.1%) showed evidence of hydrolysis of 8-hydroxyquinoline-beta-D-galactoside . No false-positive results were observed with either substrate.

J Bacteriol, 1996 Oct, 178(20), 5916 - 24
Identification of the galE gene and a galE homolog and characterization of their roles in the biosynthesis of lipopolysaccharide in a serotype O:8 strain of Yersinia enterocolitica; Pierson DE et al.; A clone that complements mutations in Yersinia enterocolitica lipopolysaccharide (LPS) core biosynthesis was isolated, and the DNA sequence of the clone was determined . Three complete open reading frames and one partial open reading frame were located on the cloned DNA fragment . The first, partial, open reading frame had homology to the rfbK gene . The remaining reading frames had homology to galE, rol, and gsk . Analysis of the galE homolog indicates that although it can complement an Escherichia coli galE mutant, its primary function in Y . enterocolitica is not in the production of UDP galactose but, instead, some other nucleotide sugar required for LPS biosynthesis . This gene has been renamed lse, for LPS sugar epimerase . The rol homolog has been demonstrated to have a role in Y . enterocolitica serotype 0:8 O-polysaccharide antigen chain length determination . An additional galE homolog has been identified in Y . enterocolitica by homology to the E . coli gene . The product of this gene has UDP galactose 4-epimerase activity in both E . coli and Y . enterocolitica . This gene is linked to the other genes of the galactose utilization pathway, similar to what is seen in other members of the family Enterobacteriaceae . Although Y . enterocolitica 0:8 strains are reported to have galactose as a constituent of LPS, a strain containing a mutation in this galE gene does not exhibit any LPS defects.

Curr Microbiol, 1996 Oct, 33(4), 261 - 5
Enterobacter kobei sp . nov., a new species of the family Enterobacteriaceae resembling Enterobacter cloacae; Kosako Y et al.; The name Enterobacter kobei sp . nov . is proposed for a group of organisms referred to as NIH Group 21 at the National Institute of Health, Tokyo . The members of this species are Gram-negative, motile rods conforming to the definition of the family Enterobacteriaceae . The DNA relatedness of 23 strains of NIH Group 21 to the representative proposed as the type strain of this species averaged 82% at 70 degrees C, whereas the relatedness to other species within the family Enterobacteriaceae was less than 42% . Because the phenotypic resemblance to Enterobacter cloacae is very close and the DNA relatedness (12-42%) is closer to species of the genus Enterobacter than to other species of the family, the members of NIH Group 21 were placed in the genus Enterobacter . Close phenotypic and genetic relationships were also found between NIH Group 21 and a member of a group of organisms referred to as Enteric Group 69 at the Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA . It is suggested that the latter could be regarded as a subspecific rank of E . kobei, though this is subject to study of further strains . The majority of strains of E . kobei were isolated from clinical specimens . A culture of the type strain (NIH 1485-79) has been deposited in the Japan Collection of Microorganisms as JCM 8580.

J Mol Biol, 1996 Sep 20, 262(2), 258 - 69
Allosteric regulation in a family of enterobacterial aspartate transcarbamylases: intramolecular transmission of regulatory signals in chimeric enzymes; Cunin R et al.; Several enterobacterial aspartate transcarbamylases (ATCases) exhibit a {2(C3):3(r2)} quaternary structure analogous to that of the Escherichia coli enzyme . Despite their conserved quaternary structures, these enzymes present substantial differences in the co-operativity of substrate binding and in their allosteric regulation by nucleotide effectors . A comparison between different enzymatic species provides an opportunity to expand our understanding of the molecular basis of allostery in ATCase . Chimeric ATCases were constructed by exchanging subdomain regions involved in quaternary structural features, such as the r1-c4 regulatory-catalytic subunit interface analyzed in this study, in order to define the involvement of this interface in the several components of allosteric regulation . The r1-c4 interface was found to constitute an essential element for the recognition and the transmission of the ATP regulatory signal in the Serratia marcescens and the Proteus vulgaris ATCases, as it does in the E . coli ATCase . Besides, the specific amino acid composition of the C-terminal region of the regulatory chain and its interactions with the amino acid residues in the 240s loop of the catalytic chain (r1-c4 interactions) were found to modulate the amplitude of the enzyme's response to ATP . The C-terminal region of the regulatory chain did not appear to participate directly in the regulation of the three native ATCases by CTP . Even when CTP acts as an activator, as in the P . vulgaris and S . marcescens ATCases, its signal follows a route distinct from that of the general activator ATP . Synergistic inhibition by CTP and UTP was found to involve the transmission of a specific UTP signal . This signal appeared different in the various ATCases, involving the C-terminal region of the regulatory chain in the E . coli and S . marcescens ATCases but not in the P . vulgaris ATCase.

Pol Merkuriusz Lek, 1996 Sep, 1(3), 216 - 8
{Postoperative wound infections in patients from the surgical department}; Wydmuch Z et al.; The microbiological evaluation of postoperative wound infections is discussed in aspects of risk factors . In analyzed material Enterobacteriaceae and Staphylococci coagulase-positive were detected as a main cause of infection.

Mikrobiol Z, 1996 Sep-Oct, 58(5), 96 - 9
{The use of the polymerase chain reaction method for the identification of representatives of the genus Enterococcus}; Kovalenko NK et al.; The possibility of the use of repetitive extragenic palindrome (REP)-specific primers to PCR-fingerprint analysis of Enterococcus genomes has been shown for the first time . Presence of the similar PCR products, and first of all the fragment 950 bp in size, has been observed in all the strains studied . Differences in PCR-product composition displayed genetical heterogeneity between Enterococcus faecium strains . These data evidence for the wide distribution of the REP, and rather high level of homology of the REP sequences among enterobacterial genomes.

Genetika, 1996 Sep, 32(9), 1184 - 90
{Identification of genes controlling the transition of Salmonella typhimurium bacteria to a non-culturable state}; Romanova IuM et al.; Mutants of Salmonella typhimurium with an impaired process of transition to the nonculturable state were tainted . Mutants were divided into four phenotypic groups . In four mutants (representatives of each phenotypic group), genes with TnPhoA transposon insertions were cloned; these insertions caused a disturbance in the process of mutant cell transition to the nonculturable state . Nucleotide sequences of mutant gene fragments were determined . Comparison of nucleotide sequences obtained with a data bank on DNA nucleotide sequences of enterobacterial genomes allowed the identification of four genes involved in the control of nonculturable form generation in salmonellae.

Klin Lab Diagn, 1996 Sep-Oct, (5), 43 - 5
{Methods of intraspecies differentiation of Enterobacter cloacae by biochemical reactions}; Priamukhina NS et al.; Three methods of intraspecies differentiation of Enterobacter cloacae by biochemical tests were compared on 14 clinical strains of different origin and 1 reference strain of this enterobacterium . The methods employed were the original and modified Old's method of biotyping and a method for assessing the biochemical profile of E . cloacae strains using bioMerieux API 20E system (France) . Modified Old's method was found to be the most convenient for practical studies.

Klin Lab Diagn, 1996 Sep-Oct, (5), 41 - 3
{Modified method of inoculation of hemocultures from patients with suppurative-septic diseases and typhoid-paratyphoid fever}; Iskhakova KhI et al.; A modified method of isolating hemocultures in pyoseptic processes is proposed . It consists in combined use of two known methods: inoculation of the blood by in-depth method and preliminary hemolysis of the blood, and use of commercial medium for assessing the sterility as the nutrient base . High efficacy of the proposed method has been demonstrated in experiments with 17 reference strains of microorganisms . The new approach helped improve the isolation rate of opportunistic enterobacteria, nonfermenting gram-negative bacteria, staphylococci, highly demanding streptococci, and other microorganisms similar in nutrient requirements, as well as the agents of typhoid and paratyphoid fever . This permits unifying the methods of investigation of hemocultures in pyoseptic diseases and typhoid-paratyphoid fevers'.

Klin Lab Diagn, 1996 Sep-Oct, (5), 35 - 9
{A comparative study of the effectiveness of commercial microtest systems for identification of microorganisms of different groups in clinical microbiology}; Skala LZ et al.; Studies of 806 strains of cultures isolated from pathological material demonstrated the possibility of using microtest systems MMTE1 and 2 (ALLERGEN Research and Production Plant in the town of Stavropol) and ENTEROtest 1 and 2 and ENTEROtest 16 for identification of enterobacteria and NEFERMtest, STAPHYtest, STREPTOtest, and ANAEROtest for the identification of respective groups of microorganisms at practical microbiological laboratories (Lachema, Czechia) . The microtest kits are easy to use and fit for mass screenings; they permit simultaneous testing in 9 to 23 biochemical tests . Use of these test kits allows species identification of 63.3 to 80.7% cultures making use of biochemical activity tables and indexes recommended in instructions for the use of microtest kits and 85.6 to 96.1% cultures making use of IDENT computer software . Introduction of microtest kits in the practical activity of microbiological laboratories will appreciably improve the quality of microbiological investigations and allow the use of automated microbiological systems.

Klin Lab Diagn, 1996 Sep-Oct, (5), 29 - 35
{Use of microtest systems for identification of newly isolated clinical strains}; Savitskaia KI et al.; Species appurtenance of 425 clinical strains isolated from various types of material from December 1993 to November 1994 was identified using Lachema (Czechia) Micro-la-test . There were 99 staphylococcal, 139 streptococcal, 119 enterobacterial cultures, and 68 nonfermenting gram-negative bacteria . The microorganisms were characterized completely according to their code in 67.7% cases (STAPHYtest), 54% (STREPTOtest), 25.2% (ENTEROtest), and 22.1% (NEFERMtest) . False-positive reactions in the control were detected in 22.2% (STAPHYtest), 33.3% (STREPTOtest), 11.8% (ENTEROtest), and 41.7% (NEFERMtest) of the number of biochemical characteristics in a plaque . Unclear reactions (+/-) making identification difficult were observed in 100% cases for STAPHYtest, 83.3% for STREPTOtest, 91.7% for ENTEROtest-1, and 58.3% for NEFERMtest . Atypical reactions, not corresponding to the studied species, were observed in 62.5% cases with STAPHYtest, 41.7% with STREPTOtest, 66.7% with ENTEROtest-1, and 58.3% with NEFERMtest . Still, STREPTOtest with the probability of verifying 61.5 to 87.5% of the cultures may be used for identifying the species appurtenance of alpha-hemolytic streptococci.

Diagn Microbiol Infect Dis, 1996 Sep, 26(1), 29 - 33
Timed killing kinetic studies of the interaction between ciprofloxacin and beta-lactams against gram-negative bacilli; Pohlman JK et al.; Timed killing kinetic studies were performed with ciprofloxacin in combination with aztreonam, ceftazidime, piperacillin/tazobactam, and ticarcillin/clavulanic acid against three isolates each of Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa . Each antimicrobial agent in the combination was tested at its MIC and at one-half and one-quarter of its MIC . Colony counts were determined at 0, 3, 5, and 7 hours . Synergy occurred most frequently at 7 hours and, when present, was most likely to occur when ciprofloxacin and the beta-lactam were tested at concentrations equal to their respective MICs . Synergy after 3 hours of incubation was not predictive of a synergestic interaction at 5 or 7 hours . Antagonism was noted in several instances, particularly when ciprofloxacin and the beta-lactam were combined at one-quarter of their respective MICs.

Diagn Microbiol Infect Dis, 1996 Sep, 26(1), 1 - 6
Evaluation of 500 gram negative isolates to determine the number of major susceptibility interpretation discrepancies between the Vitek and MicroScan Walkaway for 9 antimicrobial agents; Rittenhouse SF et al.; Although the Vitek and MicroScan Walkaway are two of the most commonly used automated antimicrobial susceptibility test systems, few studies have been performed comparing discrepancies between these systems . In this study, 500 Gram negative clinical isolates were tested against ampicillin, ampicillin/sulbactam, ticarcillin, ticarcillin/clavulanate, imipenem, ciprofloxacin, norfloxacin, mezlocillin, and piperacillin to determine the number of major interpretation discrepancies between the two systems . The 500 isolates consisted of 100 isolates each of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Enterobacter species . Each isolate was tested simultaneously in both systems using the same standardized inoculum . Eighty-four major discrepancies occurred, of which 48 were reproducible . The reproducible discrepancy rate, for the 4,500 isolate/antimicrobic combinations tested, was 48 of 4500 (1.06%) . The rate for individual antimicrobics varied from 17 of 500 (3.4%) for ampicillin to no discrepancies for ticarcillin or ciprofloxacin . Of the 48 reproducible discrepancies, 44 (92%) were Vitek resistant, MicroScan susceptible . Fifteen (31%) of the Vitek and 21 (44%) of the MicroScan results were confirmed by broth microdilution . Disk diffusion results were in agreement with 15 (31%) of the Vitek and 21 (44%) of the MicroScan results . Twelve (25%) of the broth microdilution and 12 (25%) of the disk diffusion results were intermediate . The broth microdilution and disk diffusion results for the 48 isolates with reproducible discrepancies were in agreement more often with MicroScan . However, there was less very major error comparing the Vitek results for these isolates to the broth microdilution and disk diffusion . Overall, the result of this evaluation indicate that the number of major interpretation discrepancies between the two systems is minimal for the isolate/antimicrobic combinations tested.

Eur J Clin Microbiol Infect Dis, 1996 Sep, 15(9), 736 - 41
Isolation of Bartonella quintana from an HIV-positive patient with bacillary angiomatosis; Schmidt HU et al.; Bartonella quintana was grown from a lysis-centrifugation blood culture of an HIV-positive man who presented with lesions of bacillary angiomatosis in skin and bones . The isolate was identified by sodium dodecylsulfate-polyacrylamide gel electrophoresis, 16S rRNA gene sequencing, and amplification of the enterobacterial repetitive intergenic consensus sequences.

Microbiologia, 1996 Sep, 12(3), 435 - 8
The effect of O-antigen on transformation efficiency in Serratia marcescens; Palomar J et al.; Serratia marcescens is an enterobacterium that exhibits very low efficiency of transformation . According to previous work, neither the bacterium restriction system nor its nuclease production accounts for this low efficiency . Differences in the efficiency of transformation from plasmid DNA were found in wild type of S . marcescens and their O-deficient spontaneous mutant strains . This phenomenon seems to be independent of plasmid size . When electroporation was used, the survival of O-mutants was much lower than those of their parental strains, but the frequencies of transformation among survivors were much higher . This suggests that the presence of the O-antigen is responsible for the low transformation frequencies observed.

Occup Environ Med, 1996 Sep, 53(9), 591 - 4
Interferences of urinary tract infection in the measurement of urinary nitrous oxide; Apostoli P et al.; OBJECTIVES: To investigate the effective role of micro-organisms in producing N2O . METHODS: The N2O in either urine samples inoculated with 24 microbial strains or urine samples from patients with urinary tract infections were measured . RESULTS: Gram negative bacilli generally produced high amounts of nitrous oxide (N2O), whereas Gram positive cocci and yeasts did not . The production of N2O depends on the incubation time and follows exponential kinetics, reaching a plateau at 48 hours . Furthermore, the results of urinocultures agreed well with N2O concentrations found in urine samples: samples negative for bacteria were found to contain very low concentrations of N2O whereas those positive--for example, for Enterobacteriaceae--gave highest N2O values . CONCLUSION: The urinary tract infections caused by Gram negative bacilli are important confounding factors in biological monitoring practices of exposure to inhalation anaesthetics . The current methods adopted to avoid these factors (urine acidification, storage of samples at 4 degrees C) are not good enough because of the relative acid tolerance of some strains and the production of N2O directly into the bladder.

Int J Food Microbiol, 1996 Sep, 32(1-2), 173 - 83
Technological and sensorial evaluation of Lactobacillus strains as starter cultures in fermented sausages; Garriga M et al.; The performance of several lactobacilli strains isolated from naturally fermented sausages as starter cultures was evaluated . Microbiological, physical and chemical changes, in addition to sensorial aspects were studied . From the 12 different strains tested, 10 were capable of leading the fermentation in every batch throughout the process . The monitoring of the inoculated strains was easily carried out by plasmid profiles and by checking the pH rate drop of the sausages, which was slower for the non-inoculated lots . Treatment using natural fermentation resulted in a product where hydrogen sulphide odours, which could be related to the higher content of Enterobacteriaceae throughout the ripening process, diminished its overall acceptability . The lots seeded with different L . sake strains were found to be low in acid in sensory evaluation, correlating with a low lactic acid content . In contrast, the L . plantarum lot gave rise to an overacidified product related to having the highest amount of lactic acid at the end of the process . As a general rule lactobacilli strains isolated from meat origins are good candidates as starter cultures in the manufacture of dry-fermented sausages and produce satisfactory products depending on the specific strains used more than on the species.

Clin Infect Dis, 1996 Sep, 23(3), 454 - 61
Efficacy of cefepime in the treatment of infections due to multiply resistant Enterobacter species; Sanders WE Jr et al.; Cefepime is a new cephalosporin with an enhanced antibacterial potency and spectrum . More rapid penetration into many gram-negative bacilli, targeting of multiple penicillin-binding proteins, and resistance to inactivation by many beta-lactamases account for its activity against organisms that have developed resistance to agents such as ceftazidime, cefotaxime, or ceftriaxone . This study identified 16 patients with 17 infections due to Enterobacter species organisms with reduced susceptibility or resistance to ceftazidime . Most isolates were multiply resistant to other beta-lactam drugs as well, but all were susceptible to cefepime . All 17 infections, which included pneumonia, urinary tract infection, intraabdominal infection, and bacteremia, responded clinically to intravenous cefepime . In particular, cefepime was successfully used in the management of cases of chronic infection that had responded poorly to repeated therapy with imipenem, aminoglycosides, or ciprofloxacin . Eradication of Enterobacter species organisms occurred at 15 (88.2%) of the 17 sites of infection . No emergence of resistance to cefepime was noted.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2173 - 7
Location of N-acetylmuramyl-L-alanyl-D-glutamylmesodiaminopimelic acid, presumed signal molecule for beta-lactamase induction, in the bacterial cell; Dietz H et al.; Using a chromatographic method for the isolation and detection of periplasmic and cytoplasmic muropeptides avoiding radioactive labeling, we found that in the ampD-negative strain JRG582 the anhydromuropeptide N-acetylmuramyl-L-alanyl-D-glutamylmesodiaminopimelic acid (anhMurNAc tripeptide) accumulates not only in the cytoplasm but also in the periplasm . Simultaneously JRG582 carrying the Enterobacter cloacae genes ampC and ampR, which are necessary for the induction of beta-lactamase expression, overproduces beta-lactamase . We confirmed that the transmembrane protein AmpG transports a precursor muropeptide into the cytoplasm and that the formation of the anhMurNAc tripeptide takes place in the cytoplasm . anhMurNAc tripeptide can then be secreted into the periplasm . Therefore, the amount of anhMurNAc tripeptide in the cytoplasm is reduced not only by AmpD but also by transport out of the cell.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2080 - 6
Characterization of IMI-1 beta-lactamase, a class A carbapenem-hydrolyzing enzyme from Enterobacter cloacae; Rasmussen BA et al.; In 1984, a year prior to the U.S . approval of imipenem for clinical use, a wound isolate and a bile isolate of Enterobacter cloacae were obtained from two patients in a California hospital . These isolates were resistant to imipenem, penicillins, and inhibitor combinations; early cephalosporins such as cephalothin, cefamandole, and cefoxitin; and cefoperazone . However, they were susceptible (MICs, < 4 micrograms/ml) to cefotaxime, ceftriaxone, ceftazidime, and moxalactam . Both strains produced an apparent TEM-1 beta-lactamase; an inducible NmcA-type imipenem-hydrolyzing beta-lactamase, IMI-1, with a pl of 7.05; and an inducible beta-lactamase with a pI of 8.1, typical of an E . cloacae AmpC beta-lactamase . Purified IMI-1 hydrolyzed imipenem and benzylpenicillin at modest rates, but more slowly than cephaloridine . The enzyme was inhibited by clavulanic acid and tazobactam . EDTA did not inhibit the cephaloridine-hydrolyzing activity . The beta-lactamase gene encoding IMI-1, imiA1, was cloned from E . cloacae 1413B . Sequence analysis identified the imiA1 gene as encoding a class A serine beta-lactamase . Both the imiA1 DNA and encoded amino acid sequences shared greater than 95% identity with the NmcA gene and its encoded protein . DNA sequence analysis also identified a gene upstream of imiA1 that shares > 95% identity with nmcR and that may encode a regulatory protein . In conclusion, IMI-1, a carbapenem-hydrolyzing beta-lactamase inhibited by clavulanic acid, was identified as a group 2f, class A, carbapenem-hydrolyzing cephalosporinase.

Antimicrob Agents Chemother, 1996 Sep, 40(9), 2029 - 33
A rob-like gene of Enterobacter cloacae affecting porin synthesis and susceptibility to multiple antibiotics; Lee EH et al.; A chromosomal gene of Enterobacter cloacae affecting the synthesis of major outer membrane proteins in E . cloacae and Escherichia coli was cloned by using selection for resistance to cefoxitin in E . coli . The presence of the gene, when plasmid-borne, led to a decrease in the amount of porin F in E . cloacae and the amount of OmpF in E . coli and caused 2- to 32-fold increases in the MICs of chloramphenicol, tetracycline, quinolones, and beta-lactam antibiotics . The gene encoded a 33-kDa protein, similar (83% identity) to the protein Rob involved in the initiation of DNA replication in E . coli, which was called RobA(EC1) by analogy . RobA from E . cloacae was found to inhibit ompF expression at the posttranscriptional level via activation of micF, a gene also apparently present in E . cloacae, as detected by PCR . As with its homolog from E . coli, RobA(EC1) is related to the XylS-AraC class of positive transcriptional regulators, along with MarA and SoxS, which also cause a micF-mediated decrease in the level of ampF expression.

Drugs, 1996 Sep, 52(3), 390 - 405
Combination antimicrobial therapy for bacterial infections . Guidelines for the clinician; Rybak MJ et al.; Therapy with antimicrobial combinations has been used as long as antimicrobials have been available . Combinations of antibiotics are often used to take advantage of different mechanisms of action and/or toxicity profiles . Well established indications for combination antimicrobial therapy include: (a) empirical treatment of life-threatening infections; (b) treatment of polymicrobial infections; (c) prevention of the emergence of bacterial resistance; and (d) for synergism . Disadvantages of combination therapy include: (a) increased expense; (b) increased risk of adverse effects; (c) antagonism; and (d) superinfection . Combination antimicrobial therapy should be considered for the treatment of serious Gram-negative infections caused by Enterobacter cloacae, Pseudomonas aeruginosa and Serratia marcescens, and certain Gram-positive infections caused by Enterococcus spp . and Staphylococcus spp . Selection of agents should be dependent upon local susceptibility patterns, clinical experience, site of infection, potential toxicities and cost.

Chemotherapy, 1996 Sep-Oct, 42(5), 324 - 8
In vitro activity of cefetamet against enterobacteria expressing an SHV-5-type beta-lactamase; Tzouvelekis LS et al.; The in vitro activity of cefetamet against Escherichia coli, Klebsiella pneumoniae and Serratia marcescens strains expressing an SHV-5-type beta-lactamase was evaluated . Most of the examined strains were susceptible to the antibiotic . Cefetamet was found to be considerably more active than ceftazidime and aztreonam . Its activity was comparable to that of cefotaxime . Cefetamet MIC values were related to the quantity of the enzyme expressed . The SHV-5-type enzyme hydrolysed cefetamet with an efficiency (Vmax/Km) similar to that of ceftazidime.

J Clin Microbiol, 1996 Sep, 34(9), 2163 - 9
Epidemiological study of an outbreak due to multidrug-resistant Enterobacter aerogenes in a medical intensive care unit; Arpin C et al.; In 1993, 63 isolates of Enterobacter aerogenes were collected from 41 patients in a medical intensive care unit (ICU) . During the same period, only 46 isolates from 32 patients were collected in the rest of the hospital . All isolates were analyzed by antibiotic resistance phenotype, and 77 representative isolates were differentiated by plasmid restriction analysis, ribotyping, and arbitrarily primed (AP)-PCR . The extended-spectrum beta-lactamases produced by 22 strains were characterized by determination of their isoelectric points and by hybridization of plasmid DNA with specific probes . The isolates were divided into 25 antibiotic resistance phenotypes, either susceptible (group I) or resistant (group II) to aminoglycosides, and exhibited three phenotypes of resistance to beta-lactams: chromosomally derepressed cephalosporinase alone or associated with either extended-spectrum beta-lactamases (mainly of the SHV-4 type) or imipenem resistance . The results of the tests divided the 77 representative isolates (group I, n = 21; group II, n = 56) into 15 plasmid profiles, 14 ribotypes, and 15 AP-PCR patterns . Although the resistant isolates (group II) exhibited different plasmid profiles, ribotyping and AP-PCR analysis demonstrated an identical chromosomal pattern, indicating an epidemiological relatedness . They were mainly found in the medical ICU and occasionally in other units . The susceptible strains (group I) had various and distinct markers and were mainly isolated in units other than the medical ICU . In conclusion, the presence of a nosocomial outbreak in an ICU and the spread of a multidrug-resistant epidemic strain throughout the hospital was confirmed . Ribotyping and AP-PCR represent discriminatory tools for the investigation of nosocomial outbreaks caused by E . aerogenes.

Microbiology, 1996 Sep, 142 ( Pt 9), 2613 - 9
Regulatory systems modulating the transcription of the pectinase genes of Erwinia chrysanthemi are conserved in Escherichia coli; James V et al.; To depolymerize plant pectin, the phytopathogenic enterobacterium Erwinia chrysanthemi produces five isoenzymes of pectate lyases encoded by the five genes pelA, pelB, pelC, pelD and pelE . In Er . chrysanthemi, all genes involved in pectin degradation are specifically controlled by the KdgR repressor and are induced in the presence of a pectin catabolic product, 2-keto-3-deoxygluconate (KDG) . transcription of the pectinase genes is dependent on many environmental conditions . Transcriptional fusions present on low-copy-number plasmids were used to study the regulation of the pel genes in a heterologous host, Escherichia coli . Some physiological regulations that take place in Er . chrysanthemi are conserved in E . coli . The five pel fusions in E . coli are affected by growth phase, catabolite repression and anaerobic growth conditions and are induced in the presence of galacturonate, a sugar whose catabolism leads to the formation of KDG, the inducer of pel transcription in Er . chrysanthemi . Expression of pelE increased with the osmolarity of the culture medium . In contrast, the regulation of pel expression by temperature or nitrogen starvation, observed in Er . chrysanthemi, was not conserved in E . coli, suggesting that the mechanisms responsible for these regulations are specific to Er . chrysanthemi . Analysis of different E . coli mutants allowed some regulators affecting the transcription of the pel genes to be identified . In E . coli, the growth-phase regulation of the pel genes is not dependent on the RpoS sigma factor and the fnr gene is not involved in the increase of pel expression in oxygen-limited conditions . The gene hns, involved in the regulation of numerous genes, appears to affect pel expression but the effects of E . coli hns mutations are not related to osmoregulation . In contrast, this analysis clearly demonstrates the interchangeability of two regulatory systems of E . coli and Er . chrysanthemi: the global control exerted by the catabolite activator protein CAP and the specific regulation mediated by the KdgR repressor.

Appl Environ Microbiol, 1996 Sep, 62(9), 3121 - 7
Genetic relationships among strains of Xanthomonas fragariae based on random amplified polymorphic DNA PCR, repetitive extragenic palindromic PCR, and enterobacterial repetitive intergenic consensus PCR data and generation of multiplexed PCR primers useful for the identification of this phytopathogen; Pooler MR et al.; Genetic relationships among 25 isolates of Xanthomonas fragariae from diverse geographic regions were determined by three PCR methods that rely on different amplification priming strategies: random amplified polymorphic DNA (RAPD) PCR, repetitive extragenic palindromic (REP) PCR, and enterobacterial repetitive intergenic consensus (ERIC) PCR . The results of these assays are mutually consistent and indicate that pathogenic strains are very closely related to each other . RAPD, ERIC, and REP PCR assays identified nine, four, and two genotypes, respectively, within X . fragariae isolates . A single nonpathogenic isolate of X . fragariae was not distinguishable by these methods . The results of the PCR assays were also fully confirmed by physiological tests . There was no correlation between DNA amplification product patterns and geographic sites of isolation, suggesting that this bacterium has spread largely through exchange of infected plant germ plasm . Sequences identified through the RAPD assays were used to develop three primer pairs for standard PCR assays to identify X . fragariae . In addition, we developed a stringent multiplexed PCR assay to identify X . fragariae by simultaneously using the three independently derived sets of primers specific for pathogenic strains of the bacteria.

Pediatrics, 1996 Sep, 98(3 Pt 1), 357 - 61
Nosocomial infections among neonates in high-risk nurseries in the United States . National Nosocomial Infections Surveillance System; Gaynes RP et al.; BACKGROUND: Nosocomial infections result in considerable morbidity and mortality among neonates in high-risk nurseries (HRNs) . PURPOSE: To examine the epidemiology of nosocomial infections among neonates in level III HRNs . METHODS: Data were collected from 99 hospitals with HRNs participating in the National Nosocomial Infections Surveillance system, which uses standard surveillance protocols and nosocomial infection site definitions . The data included information on maternal acquisition of and risk factors for infection, such as device exposure, birth weight category (< or = 1000, 1001 through 1500, 1501 through 2500, and > 2500 g), mortality, and the relationship of the nosocomial infection to death . RESULTS: From October 1986 through September 1994, these hospitals submitted data on 13 179 nosocomial infections . The bloodstream was the most frequent site of nosocomial infection in all birth weight groups . Nosocomial pneumonia was the second most common infection site, followed by the gastrointestinal and eye, ear, nose, and throat sites . The most common nosocomial pathogens among all neonates were coagulase-negative staphylococci, Staphylococcus aureus, enterococci, Enterobacter sp, and Escherichia coli . Group B streptococci were associated with 46% of bloodstream infections that were maternally acquired; coagulase-negative staphylococci were associated with 58% of bloodstream infections that were not maternally acquired, most of which (88%) were associated with umbilical or central intravenous catheters . CONCLUSIONS: Bloodstream infections, the most frequent nosocomial infections in all birth weight groups, should be a major focus of surveillance and prevention efforts in HRNs . For bloodstream infections, stratification of surveillance data by maternal acquisition will help focus prevention efforts for group B streptococci outside the HRN . Within the nursery, bloodstream infection surveillance should focus on umbilical or central intravenous catheter use, a major risk factor for infection.

Curr Microbiol, 1996 Sep, 33(3), 141 - 6
Ultraviolet-B lethal damage on Pseudomonas aeruginosa; Degiorgi CF et al.; Pseudomonas aeruginosa has shown an increased sensitivity compared with that of Escherichia coli and Enterobacter cloacae, when they were exposed to 0.4 kJ/m2 of ultraviolet-B radiation . The rapid decay in cell viability observed in Pseudomonas aeruginosa after the irradiation was influenced by factors such as culture media and the presence of pyocyanine during the irradiation . The radioinduced lethal damage could be prevented by photoreactivating treatment, indicating that pyrimidine dimer formation was the mechanism causing bacterial death . The results indicate that several environmental conditions may act as protective agents against ultraviolet-B-induced damage.

Lett Appl Microbiol, 1996 Aug, 23(2), 104 - 6
Variation in Salmonella core lipopolysaccharide as detected by the monoclonal antibody M105; Mansfield LP et al.; The lipopolysaccharide antigenicity of 22 Salmonella strains (representing nine serogroups) and four non-salmonellae Enterobacteriaceae to the Salmonella genus specific monoclonal antibody M105 was analysed . The monoclonal antibody M105 reacted with all 22 Salmonella strains . Probing SDS-PAGE separated LPS molecules with MAb M105 revealed that the antibody reacted with the core region of all Salmonella serovars . However, no reaction was obtained to the long-chain LPS of serovars O (Salm . adelaide and Salm . ealing), C1 (Salm . infantis, Salm . livingstone and Salm . virchow) or Salm . arizonae . It is plausible that the presence of a second core antigenic type results in the lack of reaction between long-chain LPS and the Salmonella genus specific monoclonal antibody M105.

Eur J Clin Microbiol Infect Dis, 1996 Aug, 15(8), 683 - 5
In vitro activity of trovafloxacin versus ciprofloxacin against clinical isolates; Verbist L et al.; The comparative in vitro activity of trovafloxacin (CP 99,219), a new fluoroquinolone, was evaluated against 511 clinical isolates . MICs of trovafloxacin were fourfold higher than those of ciprofloxacin for 184 Enterobacteriaceae and 110 non-fermentative gram-negative bacilli . However, trovafloxacin was 16-fold more active than ciprofloxacin against 162 gram-positive staphylococci, pneumococci, streptococci, and enterococci, and two- to fourfold more active against Haemophilus influenzae and Moraxella catarrhalis . MICs of trovafloxacin were correspondingly higher for strains with acquired resistance to ciprofloxacin.

Eur J Clin Microbiol Infect Dis, 1996 Aug, 15(8), 678 - 82
In vitro activity and selection of disk content for disk diffusion susceptibility tests with trovafloxacin; Fuchs PC et al.; The activity of the new fluoroquinolone trovafloxacin (CP-99,219) was compared with that of ciprofloxacin and ofloxacin against 517 bacterial isolates representing 50 different species . Against members of the family Enterobacteriaceae, all three drugs showed good in vitro activity . Against most anaerobic bacteria, Staphylococcus, Streptococcus, and Enterococcus species, trovafloxacin was four- to sixteenfold more active than ciprofloxacin . For disk diffusion testing, 10 micrograms trovafloxacin disks gave satisfactory results . Tentative criteria are proposed for use during clinical studies.

Int J Food Microbiol, 1996 Aug, 31(1-3), 221 - 9
Effect of modified atmosphere packaging on the TVB/TMA-producing microflora of cod fillets; Debevere J et al.; Cod fillets (Gadus morhua) were packed under modified atmospheres, with four different gas compositions (60% CO2-10% O2-30% N2, 60% CO2-20% O2-20% N2, 60% CO2-30% O2-10% N2, 60% CO2-40% O2), and stored at 6 degrees C . Plate counts were carried out after 3, 4, 5, 6 and 7 days, to follow the growth of aerobic and anaerobic bacteria, lactic acid bacteria, H2S-producing bacteria and Enterobacteriaceae . The production of total volatile bases (TVB) and trimethylamine (TMA), and the changes in pH of the fillets were measured . Modified atmosphere packaging (MAP) had in general an inhibitory effect on the growth of the microflora but limited inhibition of the production of TVB and TMA . Despite the fact that increased oxygen proportions in the atmosphere contributed in a slightly lower production of TMA, all the samples had a TVB and TMA content high enough to be considered as spoiled after 4 days' storage at 6 degrees C . A total aerobic plate count at 25 degrees C of a 10(6) cfu/g, combined with the presence of only a 10(3) cfu/g of H2S-producing bacteria, which are normally considered as TMAO-reducing organisms in fish, cannot explain the strong increase in TMA . A high cell concentration of more than 10(8) cfu/g of Shewanella putrefaciens is required for production of a TMA level normally found in spoiled fish . This suggests that there could be another type of bacterium in fish, not involved in the spoilage of unpacked fish, which is resistant to 60% CO2, is not H2S-producing, and shows a high TMAO-reducing capacity . This bacterium could be Photobacterium phosphoreum.

Mol Microbiol, 1996 Aug, 21(4), 811 - 21
The FinOP repressor system of plasmid R1: analysis of the antisense RNA control of traJ expression and conjugative DNA transfer; Koraimann G et al.; A key determinant of the frequency of IncF plasmid-mediated DNA transfer between enterobacterial cells is the FinOP system . traJ, a positive regulator of the transfer (tra) genes is controlled at the post-transcriptional level by two negative elements, finP and finO . FinP is a plasmid-specific antisense RNA, whereas finO encodes a proteic co-repressor which is not plasmid specific but exchangeable among F-like plasmids . We designed a traJ-lacZ test system that allowed us to monitor the effects of FinP and various FinP mutants on traJ expression . Furthermore, the introduction of finO into the test system enabled us to assess the function of FinO in the interaction of FinP with its target, the traJ mRNA . In this test system, FinP, expressed from a single-copy plasmid, in the absence of FinO, repressed traJ expression six-fold . When expressed from a pBR322-derived multicopy plasmid FinP repressed traJ expression approx . 2000-fold . This result unambiguously demonstrated that FinP is sufficient to repress traJ expression in a gene dosage-dependent manner . Mutations of finP creating base exchanges either in loop I or loop II of the two stem-loop structures of the antisense RNA led to a dramatic decrease in the repressor activity . In a combined loop I-loop II mutation the repressor activity was almost completely lost, supporting the model that the first critical interaction between the two RNA molecules occurs via 'kissing' of both loops of the RNAs . Addition of finO to the test system enhanced the repression of traJ expression by FinP by up to two orders of magnitude . This effect of FinO on FinP activity in vivo might indicate that FinO, in addition to its function as an RNA stabilizer, promotes complex formation between the target mRNA and the antisense RNA . Such a function of FinO has recently been shown to exist in vitro (van Biesen and Frost (1994) Mol Microbiol 14: 427-436).

J Chemother, 1996 Aug, 8(4), 266 - 9
The origin, by mutation, of high level resistance to ceftazidime and cefotaxime in a clinical isolate of Enterobacter cloacae; Blahova J et al.; Although strains of Enterobacter sp . produce a chromosomal AmpC beta-lactamase, they have been, in general, susceptible to cefotaxime or ceftazidime . But now resistance to ceftazidime has increased in nosocomial Enterobacter strains, reaching the level of 40% . A chromosomal mutation in the amp operon coding the production of AmpC type beta-lactamase may cause a change in the conversion of a susceptible strain of Enterobacter to a highly resistant mutant . The production of AmpC enzyme is inducible and third-generation cephalosporins are weak inducers of AmpC production . Spontaneous mutations (or insertions of transposons) in the regulatory region of amp operon might create constitutive (derepressed) overproducers of large amounts of AmpC molecules . As a consequence, such cells acquire a stable resistance to beta-lactam antibiotics including cefotaxime or ceftazidime . We describe the origin of mutants of a clinical isolate of Enterobacter cloacae that acquired high-level resistance to ceftazidime followed by the resistance to cefotaxime and/or aztreonam due to a second mutation.

Mol Microbiol, 1996 Aug, 21(3), 479 - 89
Intracellular endosymbiotic bacteria of Camponotus species (carpenter ants): systematics, evolution and ultrastructural characterization; Schroder D et al.; Intracellular endosymbiotic bacteria inherent to ants of the genus Camponotus were characterized . The bacteria were localized in bacteriocytes, which are specialized cells of both workers and queen ants; these cells are intercalated between epithelial cells of the midgut . The bacteriocytes show a different morphology from the normal epithelial cells and carry a large number of the rod-shaped Gram-negative bacteria free in the cytoplasm . The bacteria were never observed in the neighbouring epithelial cells, but they were found intracellularly in oocytes, strongly indicating a maternal transmission of the bacteria . The 16S DNA encoding rrs loci of the endosymbionts of four species of the genus Camponotus derived either from Germany (C . herculeanus and C . ligniperdus), North America (C . floridanus) or South America (C . rufipes) were cloned after polymerase chain reaction (PCR) amplification using oligonucleotides complementary to all so far known eubacterial rrs sequences . The DNA sequences of the rrs loci of the four endosymbionts were determined, and, using various genus- and species-specific oligonucleotides derived from variable regions in the rrs sequences, the identity of the bacteria present in the bacteriocytes and the ovarian cells was confirmed by PCR and in situ hybridization techniques . Comparison of the 16S DNA sequences with the available database showed the endosymbiotic bacteria to be members of the gamma-subclass of Proteobacteria . They formed a distinct taxonomic group, a sister taxon of the taxons defined by the tsetse fly and aphid endosymbionts . Within the gamma-subclass, the cluster of the ant, tsetse fly and aphid endosymbionts are placed adjacent to the family of Enterobacteriaceae . The evolutionary tree of the ant endosymbionts reflects the systematic classification and geographical distribution of their host insects, indicating an early co-evolution of the symbiotic partners and a vertical transmission of the bacteria.

Proteins, 1996 Aug, 25(4), 473 - 85
The roles of residues Tyr150, Glu272, and His314 in class C beta-lactamases; Dubus A et al.; Serine beta-lactamases contribute widely to the beta-lactam resistance phenomena . Unfortunately, the intimate details of their catalytic mechanism remain elusive and subject to some controversy even though many "natural" and "artificial" mutants of these different enzymes have been isolated . This paper is essentially focused on class C beta-lactamases, which contain a Tyr (Tyr150) as the first residue of the second conserved element, in contrast to their class A counterparts, in which a Ser is found in the corresponding position . We have modified this Tyr residue by site-directed mutagenesis . On the basis of the three-dimensional structure of the Enterobacter cloacae P99 enzyme, it seemed that residues Glu272 and His314 might also be important . They were similarly substituted . The modified enzymes were isolated and their catalytic properties determined . Our results indicated that His314 was not required for catalysis and that Glu272 did not play an important role in acylation but was involved to a small extent in the deacylation process . Conversely, Tyr150 was confirmed to be central for catalysis, at least with the best substrates . On the basis of a comparison of data obtained for several class C enzyme mutants and in agreement with recent structural data, we propose that the phenolate anion of Tyr150, in conjunction with the alkyl ammonium of Lys315, acts as the general base responsible for the activation of the active-site Ser64 during the acylation step and for the subsequent activation of a water molecule in the deacylation process . The evolution of the important superfamily of penicillin-recognizing enzymes is further discussed in the light of this proposed mechanism.

Mol Cell Probes, 1996 Aug, 10(4), 233 - 46
Diagnostic potential of sefA DNA probes to Salmonella enteritidis and certain other O-serogroup D1 Salmonella serovars; Doran JL et al.; Salmonella enteritidis thin fimbriae, SEF14, were found to be restricted to S . dublin and the predominantly poultry-associated members of the Salmonella O-serogroup D1, S . enteritidis, S . berta, S . gallinarum and S . pullorum, when tested by Western and ELISA analysis from among 90 Salmonella isolates of 42 serovars, as well as from members of several related genera of the Enterobacteriaceae . These five serovars and a single isolate of S . typhi (D1) were also detected by hybridization of genomic DNA from 732 Salmonella isolates of 117 serogroups to gene probes derived from the S . enteritidis sefA (fimbrin gene), sefB (chaperone) or sefC (outer membrane protein) genes encoding proteins involved in SEF14 biosynthesis . None of 250 Enterobacteriaceae or 27 other eubacterial isolates tested hybridized to the sef probes . The sefA, sefB and sefC genes were amplified from these six Salmonella serovars by PCR using primer pairs designed from sefA, sefB or sefC of S . enteritidis . DNA sequencing of sefA genes from these five serovars indicated limited sequence variability among sefA genes and recognition of individual base pairs which could potentially differentiate certain strains of S . enteritidis, S . dublin and S . gallinarum.

J Hosp Infect, 1996 Aug, 33(4), 273 - 8
Killing activity of microwaves in milk; Kindle G et al.; The killing activity of microwaves of 2450 MHz frequency and 600 W power on Pseudomonas aeruginosa, Escherichia coli, Enterobacter sakazakii, Klebsiella pneumoniae, Staphylococcus aureus, Candida albicans, Mycobacterium terrae and poliomyelitis vaccine-virus suspended in five infant formula preparations was investigated . The samples were brought to the boil (85-100 s depending on milk type) . They had reached average temperatures of 82-93 degrees C at this point . Most of the vegetative organisms were killed . In those samples where growth was still detectable after microwave treatment, a significant reduction in viable micro-organisms (at least 5000-fold) was noted . We conclude that microwave beating to the boil is a convenient and fast method to reduce microbial contamination of infant feeds . However, care should be taken to ensure that milk is adequately cooled to the required temperature before it is fed to an infant.

Antimicrob Agents Chemother, 1996 Aug, 40(8), 1953 - 6
Sequencing and analysis of four new Enterobacter ampD Alleles; Ehrhardt AF et al.; Sequences of ampD genes from wild-type, temperature-sensitive, and stably derepressed mutants of the wild-type strain of Enterobacter cloacae 029 and the hyperinducible strain E . cloacae 1194E were determined and compared with the ampD gene of the wild-type strain E . cloacae 14 . Seventy nucleotide differences were found between the wild-type sequences, resulting in 13 amino acid changes . The deduced amino acid changes do not correspond to published AmpC regulation mutations and expand the number of known mutations leading to altered AmpC beta-lactamase expression in members of the family Enterobacteriaceae.

Antimicrob Agents Chemother, 1996 Aug, 40(8), 1914 - 8
Comparison of three different in vitro methods of detecting synergy: time-kill, checkerboard, and E test; White RL et al.; An in vitro method of detecting synergy which is simple to perform, accurate, and reproducible and has the potential for clinical extrapolation is desirable . Time-kill and checkerboard methods are the most widely used techniques to assess synergy but are time-consuming and labor-intensive . The Epsilometer test (E test), a less technically demanding test, has not been well studied for synergy testing . We performed synergy testing of Escherichia coli ATCC 35218, Enterobacter cloacae ATCC 23355, Pseudomonas aeruginosa ATCC 27853, and Staphylococcus aureus ATCC 29213 with various combinations of cefepime or ceftazidime with tobramycin or ciprofloxacin using time-kill, checkerboard, and E test techniques . Time-kill testing was performed against each organism alone and in combinations at one-fourth times the MIC (1/4 x MIC) and 2 x MIC . With checkerboard tests, the same combinations were studied at concentrations ranging from 1/32 x to 4 x MIC . Standard definitions for synergy, indifference, and antagonism were utilized . E test strips were crossed at a 90 degree angle so the scales met at the MIC of each drug alone, and the fractional inhibitory concentrations index was calculated on the basis of the resultant zone on inhibition . All antimicrobial combinations demonstrated some degree of synergy against the test organisms, and antagonism was infrequent . Agreement with time-kill testing ranged from 44 to 88% and 63 to 75% by the checkerboard and E test synergy methods, respectively . Despite each of these methods utilizing different conditions and endpoints, there was frequent agreement among the methods . Further comparisons of the E test synergy technique with the checkerboard and time-kill methods are warranted.

Antimicrob Agents Chemother, 1996 Aug, 40(8), 1801 - 5
Group of peptides that act synergistically with hydrophobic antibiotics against gram-negative enteric bacteria; Vaara M et al.; A synthetic peptide, KFFKFFKFFK {corrected}, consisting of cationic lysine residues and hydrophobic phenylalanine residues was found to sensitize gram-negative bacteria to hydrophobic and amphipathic antibiotics . At a concentration of 3 micrograms/ml, it decreased the MIC of rifampin for smooth, encapsulated Escherichia coli by a factor of 300 . Other susceptible bacterial species included Enterobacter cloacae, Klebsiella pneumoniae, and Salmonella typhimurium, but Pseudomonas aeruginosa was resistant . Similar results were obtained with another synthetic peptide, IKFLKFLKFLK {corrected} . The fractional inhibitory concentration indices for the synergism of these peptides with rifampin, erythromycin, fusidic acid, and novobiocin were very close to those determined for the previously characterized potent outer-membrane-disorganizing agents polymyxin B nonapeptide and deacylpolymyxin B . KFFKFFKFFK {corrected} had direct activity against the gram-positive organism Micrococcus strain ML36, was strongly hemolytic, and was as active on polymyxin-resistant E . coli mutants as on their parent . These three attributes made KFFKFFKFFK {corrected} different from polymyxin derivatives and similar to cationic detergents, such as cetylpyridinium chloride . However, whereas the MIC of cetylpyridinium chloride for E . coli is low (0.5 to 4 micrograms/ml), that of KFFKFFKFFK {corrected} is much higher (30 to 100 micrograms/ml) . Other groups of synthetic peptides studied included polymyxin-like peptides with an intrachain disulfide bridge . Their synergism with antibiotics was less marked . Still other peptides, including KEKEKEKEKE and KKKKKKFLFL, lacked any synergism with the probe antibiotics.

J Clin Microbiol, 1996 Aug, 34(8), 1963 - 9
Adhesive properties and antibiotic resistance of Klebsiella, Enterobacter, and Serratia clinical isolates involved in nosocomial infections; Livrelli V et al.; Intestinal colonization by Klebsiella, Enterobacter, and Serratia (KES) strains is a crucial step in the development of nosocomial infections . We studied the adhesive properties, antibiotic resistance, and involvement in colonization or infection of 103 KES clinical isolates: 30 Klebsiella pneumoniae (29%), 16 Klebsiella oxytoca (15%), 30 Enterobacter aerogenes (29%), 14 Enterobacter cloacae (14%), and 13 Serratia sp . (13%) isolates . Half of them were resistant to several antimicrobial agents, including aminoglycosides and beta-lactam antibiotics . A total of 27 of 30 K . pneumoniae isolates (90%) adhered to the human cell line Intestine-407 (Int-407), while none of the K . oxytoca or E . aerogenes isolates and only 2 of the E . cloacae isolates adhered . Three adhesive patterns were observed for K . pneumoniae: an aggregative adhesion in 57% of the isolates, a diffuse adhesion in only one isolate, and a new pattern, localized adhesion, in 30% of the isolates . While most of the sensitive strains adhered with the aggregative phenotype, the localized pattern was associated with resistant K . pneumoniae isolates producing the CAZ-5 beta-lactamase . Furthermore, 45% of such localized-adhesion isolates were involved in severe infections . The distributions of type 1 and type 3 fimbriae, enteroaggregative E . coli, and cf29, pap, and afa/Dr adhesin-encoding genes were determined by using specific DNA probes . No relationship was found between the adhesive pattern and the production of specific fimbriae, suggesting that several unrecognized adhesive factors are involved . Our study indicates that special adhesive properties associated with resistance to antimicrobial agents could account for the pathogenicity of certain nosocomial strains.

Fortschr Neurol Psychiatr, 1996 Aug, 64(8), 297 - 306
{Bacterial brain abscess--experiences with 67 patients}; Berlit P et al.; Sixty-seven patients with brain abscess were managed over 19 years (1975-1993) . Our series had a 2.5 to 1 male predominance; the age distribution was from 3 days to 81 years . The underlying conditions of hematogenic brain abscesses (n = 33; 49%) included lung infections (n = 16), heart disease (n = 4), sepsis (n = 10), and other foci (n = 3) . Otolaryngologic infections led to the abscess in 10 cases; there were 9 traumatic abscesses . The causes remained unknown in 15 cases . There were 47 solitary abscesses (70%) and 20 multiple abscesses . The most frequent presenting signs and symptoms were neurologic deficits (n = 17), disturbances of consciousness (n = 14), seizures (n = 6), and headaches, meningism and vomiting (n = 13) . Causative organisms were isolated in 39 cases (58%) and included staphylococci (n = 6), streptococci (n = 6), enterobacteriae (n = 2), and anaerobic pathogens (n = 9) . The most reliable laboratory sign of inflammation was an elevated ESR (52/59 patients) . With the advent of computed tomography, burr hole aspiration of the abscess with or without drainage was possible in 30 cases; the mortality in this subgroup was 9% . All 4 patients with surgical excision in the pre CT-era died . The mortality of patients treated with antibiotics only was 62% (18/29) . Overall mortality was 37% (25/67), including 5 cases with post mortem-diagnosis of brain abscess . Good recovery was achieved in 29/42 survivors . Predictors of a poor outcome were the patient's age, the level of consciousness, multiple abscesses, polybacterial cultures, and a hematogenic etiology, but not the size of the abscess.

FEMS Microbiol Lett, 1996 Aug 1, 141(2-3), 221 - 5
Structural studies on the Escherichia coli O101 lipopolysaccharide found in association with F41 and K99 fimbriae; Karamanos Y et al.; In this study it was shown that the O101 lipopolysaccharide isolated from Escherichia coli B41 did not contain an O-specific polysaccharide and that its sugar moiety is probably restricted to the core oligosaccharide . It is characterized by the presence of galactose, glucose, N-acetylglucosamine, heptose and 3-deoxy-D-manno-2-octulosonic acid and the fatty acid composition is typical of an Enterobacteriaceae lipopolysaccharide . Methylation analysis indicated terminal non-reducing galactose and glucose and also 1,2-linked glucose which is a substitution pattern typical of an E . coli lipopolysaccharide core oligosaccharide . The obtained structural information is sufficient to explain the previously observed interactions between the O101 lipopolysaccharide and the K99 lectin.

Epidemiol Infect, 1996 Aug, 117(1), 59 - 67
Detection of pathogenic Yersinia enterocolitica using the multiplex polymerase chain reaction; Harnett N et al.; A multiplex polymerase chain reaction (PCR) was developed to detect the presence of the ail, yst, and virF genes of Yersinia enterocolitica simultaneously, quickly and accurately . The amplified fragment sizes were 356 base-pairs (bp) for the ail gene, 134 bp for the yst gene, and 231 bp for the virF gene . The specificity of the amplified products was confirmed by hybridization with digoxigenin-labelled oligonucleotide probes . Amplification was successful whether the template was derived from a single colony of bacteria, aliquots of boiled bacterial suspensions, from DNA extracted from pure or mixed cultures or from stool specimens . Amplification of the virF gene was also achieved from strains of Y . pseudotuberculosis carrying the 70 kb plasmid but not with preparations from other related Yersinia species or from other members of the family Enterobacteriaceae . The detection limit we established was 5-10 colony forming units per millilitre (cfu/ml) and 1.0 pg of DNA.

J Bacteriol, 1996 Aug, 178(16), 4885 - 93
Organization of the Escherichia coli K-12 gene cluster responsible for production of the extracellular polysaccharide colanic acid; Stevenson G et al.; Colanic acid (CA) is an extracellular polysaccharide produced by most Escherichia coli strains as well as by other species of the family Enterobacteriaceae . We have determined the sequence of a 23-kb segment of the E . coli K-12 chromosome which includes the cluster of genes necessary for production of CA . The CA cluster comprises 19 genes . Two other sequenced genes (orf1.3 and galF), which are situated between the CA cluster and the O-antigen cluster, were shown to be unnecessary for CA production . The CA cluster includes genes for synthesis of GDP-L-fucose, one of the precursors of CA, and the gene for one of the enzymes in this pathway (GDP-D-mannose 4,6-dehydratase) was identified by biochemical assay . Six of the inferred proteins show sequence similarity to glycosyl transferases, and two others have sequence similarity to acetyl transferases . Another gene (wzx) is predicted to encode a protein with multiple transmembrane segments and may function in export of the CA repeat unit from the cytoplasm into the periplasm in a process analogous to O-unit export . The first three genes of the cluster are predicted to encode an outer membrane lipoprotein, a phosphatase, and an inner membrane protein with an ATP-binding domain . Since homologs of these genes are found in other extracellular polysaccharide gene clusters, they may have a common function, such as export of polysaccharide from the cell.

Clin Exp Immunol, 1996 Aug, 105(2), 231 - 7
Yersinia-hsp60-reactive T cells are efficiently stimulated by peptides of 12 and 13 amino acid residues in a MHC class II (I-Ab)-restricted manner; Noll A et al.; Heat shock proteins (hsp) are immunodominant antigens in microbial infections . Previous work from this laboratory demonstrated that Yersinia-hsp60 (Y-hsp60)-reactive CD4+ alpha beta T cells play an important role for resolution of Y . enterocolitica infections in mice . In the present study we identified two epitopes of Y-hsp60 recognized by CD4+ Th1 cell clones . The epitopes comprise 12 (214-225) and 13 (74-86) amino acid (aa) residues of Y-hsp60, and are the first described for MHC class II (I-Ab) molecules . Both epitopes are also recognized by T cells isolated from mesenteric lymph nodes from mice orogastrically infected with yersiniae . Stimulation of T cells with peptides of 12 and 13 aa residues of Y-hsp60 caused highly efficient proliferation compared with longer peptides, full-length recombinant Y-hsp60, or heat-killed Yersinia (HKY) . Incubation of antigen-presenting cells with chloroquine blocked both peptide and HKY-triggered T cell proliferation, whereas cytochalasin B only blocked HKY-induced proliferation and to a lesser extent peptide-induced proliferation . The identified epitopes reside in a region of Y-hsp60 that is conserved between Enterobacteriaceae but highly variable when compared with murine or human hsp60 . Although both epitopes are identical to the related sequence of hsp60 (GroEL) of Escherichia coli, only weak T cell responses were observed upon stimulation with GroEL of E . coli, suggesting that other factors, e.g . flanking amino acid residues, might be important for antigen processing and T cell stimulation in a class II-restricted manner . Furthermore, these observations might be of significance for the rational design of subunit vaccines.

J Ethnopharmacol, 1996 Jul 26, 53(1), 51 - 4
Antibacterial activity of Helichrysum pedunculatum used in circumcision rites; Meyer JJ et al.; Antibacterial assays of Helichrysum pedunculatum showed that dichloromethane extracts are active against all the gram positive bacteria tested, as well as two gram negative bacteria, Enterobacter cloacae and Serratia marcescens . A water extract was effective against Staphylococcus aureus and Micrococcus kristinae, while a methanol extract showed no activity against any of the tested organisms . The antibacterial activity of dichloromethane extract was also investigated by direct bioassay on TLC plates against S . aureus.

Mutat Res, 1996 Jul 22, 354(2), 157 - 70
Construction of a new system for separate expression of mutagenesis proteins: the abilities to promote UV mutagenesis and interchangeability of MucA', MucB, SamA' and SamB proteins in Salmonella typhimurium; Gruz P et al.; The two distinct mucAB and samAB operons originally isolated from the plasmids of Salmonella typhimurium encode proteins engaged in induced mutagenesis . They represent two extreme cases among the so far characterized members of the enterobacterial umuDC family in respect to both the strength and the specificity of their effect . It is suggested that the MucA and SamA proteins are post-translationally processed to MucA' and SamA', respectively, which lack the N-terminal 25 amino acids and are the active species in mutagenesis . For the purpose of characterizing the individual activities of these proteins, we developed a new system for their SOS-independent separate and controllable expression in enterobacteria . Besides the matured forms of MucA', SamA' as well as MucB and SamB proteins we also expressed hybrid HisTag-MucA' and HisTag-SamA' proteins in which a synthetic 24 amino acid HisTag region replaces the natural 25 amino acid N-terminal leader present in the MucA and SamA precursors . In this study, we analyzed the effect of the mutagenesis proteins on the UV mutability of S . typhimurium YG5144 . None of the proteins, if expressed alone, promoted UV mutagenesis . Different combinations of the proteins promoted mutagenesis to different extents in the order MucA' + MucB > SamA' + SamB > or = HisTag-MucA' + MucB > or = SamA' + MucB > MucA' + SamB > HisTag-SamA' + SamB . The mutagenesis enhancing potential of the combinations with MucB protein decreased as the expression of the proteins increased while the mutagenesis enhancing potential of the combinations with SamB protein increased together with the increase in the expression . The artificially expressed MucA' + MucB proteins were as active as their MucAB counterparts expressed from the plasmid pKM101 in promoting UV mutagenesis, but they were remarkably more efficient than their pKM101-born counterparts in promoting spontaneous mutagenesis . We conclude that the MucA'B and SamA'B proteins are partly interchangeable and the functionality of the resulting A' + B complex is largely dependent on the appropriate B-protein.

Cell Immunol, 1996 Jul 10, 171(1), 30 - 40
Effects of a nonapeptide thymic hormone on intestinal intraepithelial lymphocytes in mice following administration of 5-fluorouracil; Inagaki-Ohara K et al.; A significant fraction of murine small intestinal intraepithelial lymphocytes (i-IELs) mature in local sites outside the thymus . However, there is evidence suggesting that extrathymic differentiation of i-IELs is still influenced by the thymus or thymus-derived factors . Facteur thymique serique (FTS), a nonapeptide thymic hormone, is involved in several aspects of intra- and extrathymic T cell differentiation in vivo . In this study, we investigated the effects of FTS on the kinetics of i-IELs in mice following a single administration of 5-fluorouracil (5-FU) . FTS treatment significantly accelerated the recovery in cell number of i-IELs after administration of 5-FU . Flow cytometric analysis revealed that this accelerated recovery was mainly due to a rapid increase in CD8 alpha alpha+ i-IELs . Similar findings were also evident in adult thymectomized (ATX) mice, indicating that FTS treatment caused a rapid recovery of CD8 alpha alpha+ i-IELs following 5-FU administration in the absence of a functional thymus . Furthermore, expression levels of the mRNAs for interleukin-2, interferon-gamma, and transforming growth factor beta 1 in the i-IELs were augmented by FTS treatment . Notably, FTS treatment protected mice from 5-FU-induced lethal toxicity, accompanied with an inhibition of the translocation of Enterobacteriaceae . These results suggest that FTS has an important function in the extrathymic maturation and activation of i-IELs in the small intestine following 5-FU administration, which may contribute at least partly to the protection against 5-FU-induced lethal toxicity.

Microb Drug Resist, 1996 Summer, 2(2), 273 - 6
Diffusion of carbapenems through the outer membrane of enterobacteriaceae and correlation of their activities with their periplasmic concentrations; Cornaglia G et al.; Scarce information is available on the real mechanism by which carbapenemes penetrate in Enterobacteriaceae, although a considerable amount of evidence suggests that in many species of this family the lack of certain outer membrane proteins is associated with the acquisition of resistance to these antibiotics . The existance of specific pathways for the carbapenems has never been demonstrated, although at times it has been postulated in both wild and mutant strains, on the basis of evident discordances between permeability patterns and suceptibility data . By using the Zimmerman and Rosselet technique, which requires the strain under investigation to harbor a suitable beta-lactamase, the permeability of intact Escherichia coli and Enterobacter cloacae cells to meropenem and imipenem was investigated by transferring a constructed vector carrying the carbapenem hydrolyzing CphA metallo-beta-lactamase gene into the parental strains and their porin-deficient mutants . Reduced amounts of nonspecific porins significantly reduced the penetration of both carbapenems . The virtual absence of porins caused the MICs of meropenem to increase, mostly in Enterobacter cloacae, while it did not affected the MICs of imipenem . No evidence of specific porin pathways of the type described in Pseudomonas aeruginosa was found.

Mikrobiol Z, 1996 Jul-Aug, 58(4), 93 - 109
{Rarely encountered, atypical and new species of enterobacteria}; Pokhil SI; The article characterizes "rare", atypical and new individualized representatives of Enterobacteriaceae family . Classification approach is formulated which makes it possible to subdivide enterobacteria into three groups according to frequency of isolation, genetic determination and degree of atypicality . Schemes are presented for differential diagnosis for correct carrying out laboratory investigations and adequate interpretation of bacteriological assays results.

Diagn Microbiol Infect Dis, 1996 Jul, 25(3), 133 - 5
Accurate characterization of ofloxacin susceptibility with Enterobacteriaceae using a modified GNS F6 card and the bioMerieux Vitek System; Doern GV et al.; Routine antimicrobial susceptibility testing of Enterobacteriaceae using the Vitek System (bioMerieux Vitek, Hazelwood, MO) and the GNS-F6 card revealed discrepancies between the activity of ofloxacin and ciprofloxacin, primarily with isolates of Klebsiella pneumoniae . Specifically, during a one-year period, 12% of 618 ciprofloxacin-susceptible isolates were determined to be ofloxacin resistant with the GNS-F6 card . A similar problem, but one of lower magnitude, was observed with Serratia marsescens . That these represented false ofloxacin resistance results was confirmed by comparison of broth microdilution determinations of ofloxacin MICs with F6 results on a collection of 203 fresh clinical isolates of K . pneumoniae and 39 isolates of S . marsescens . The GNS-F6 card was then modified by the manufacturer to include a new formulation of ofloxacin and assessed using a collection of 224 recent clinical isolates of Enterobacteriaceae and Pseudomonas aeruginosa, and 78 stock cultures of enteric Gram-negative bacilli selected specifically because of disproportionately high rates of fluoroquinolone resistance . No ofloxacin false resistant results were observed with this collection when the modified GNS-F6 card was evaluated in comparison to a standardized broth microdilution MIC test . The current clinical version of the Vitek System appears to accurately assess ofloxacin susceptibility.

J Antimicrob Chemother, 1996 Jul, 38(1), 127 - 32
Survey of prevalence of extended spectrum beta-lactamases among enterobacteriaceae; Chanal C et al.; During the first six months of 1990 and 1994 respectively, 3179 and 2721 non-repetitive strains of Enterobacteriaceae were isolated at the teaching hospital of Clermont-Ferrand . Extended-spectrum beta-lactamases were found in 147 isolates, mainly in Klebsiella pneumoniae (n = 73), Enterobacter aerogenes (n = 37) and Proteus mirabilis (n = 15) . TEM-3/CTX-1, SHV-4/CAZ-5 and TEM-24/CAZ-6 were the prevalent enzymes . However, the most frequently involved enzyme in 1990 was TEM-3 (48.6%) whereas in 1994 it was SHV-4 (56.0%) . Two salient features emerged from this study: the high frequency of TEM-3 production in P . mirabilis and the production of SHV-4 enzyme, heretofore observed solely in K . pneumoniae, in two other species, E . aerogenes and Escherichia coli.

Int J Food Microbiol, 1996 Jul, 30(3), 281 - 91
The effect of glucose supplementation on the spoilage microflora and chemical composition of minced beef stored aerobically or under a modified atmosphere at 4 degrees C; Lambropoulou KA et al.; Glucose was added to minced meat (pH 6.0) and stored under aerobic or a modified atmosphere (MA) composed of 80% O2 and 20% CO2 to assess the effects of carbohydrate on the microbial association and the chemical properties of the meat . The type of packaging affected the size and the final composition of the microflora . The microbial composition of the mince without added glucose in air or MA, given in log10 cfu/g respectively, were pseudomonads (9.8 and 7.3), Brochothrix thermosphacta (8.5 and 8.1), lactic acid bacteria (8.8 and 8.7), Enterobacteriaceae (7.2 and 6.1) and yeasts (4.3 and 4.2) . In mince supplemented with 0.2% (w/w) glucose, similar composition and numbers were observed . Glucose, glucose 6-phosphate and lactic acid were consumed at slower rates by the flora on meat stored under MA than by the flora on meat stored in air . The addition of glucose enhanced gluconate production by the flora on meat stored in air . D-lactic and acetic acid were produced in all samples stored under the MA.

Int J Food Microbiol, 1996 Jul, 30(3), 243 - 53
Biochemical characteristics of Enterobacter agglomerans and related strains found in buckwheat seeds; Iimura K et al.; Thirty strains of bacteria were randomly isolated and identified from buckwheat seeds . The phenotypic characteristics of these strains agree well with those of the Enterobacter agglomerans-Erwinia herbicola complex . On the basis of the difference in indole production and gas production from D-glucose, the isolates were divided into 3 phenotypic groups, viz . I, II and III . Twenty two strains were in phenotypic group 1, which is negative for indole production and gas production from D-glucose, and resembles Pantoea agglomerans . All six strains in phenotypic group II, which is positive for indole production and negative for gas production from D-glucose, were identified as Erwinia ananas . Two strains in phenotypic group III, which is negative for indole production and positive for gas production from D-glucose, were identified as Rahnella aquatilis.

J Infect, 1996 Jul, 33(1), 33 - 7
Bacteriuria in a cohort of predominantly HIV-1 seropositive female commercial sex workers in Nairobi, Kenya; Ojoo J et al.; Although significant bacteriuria and urinary tract infection are more common in immunocompetent women than men, studies linking HIV immunosuppression with an increased risk of developing urinary infection have so far only been carried out in men . We therefore examined the relationship between bacteriuria and HIV status and CD4+cell count in a relatively homogeneous cohort of female commercial sex workers (CSW) attending a community clinic in Nairobi . Two hundred and twenty-two women were enrolled, and grouped according to HIV status and CD4 count . Group 1 were HIV seronegative (n = 52); Group 2 were HIV seropositive with CD4 + counts above 500 x 10(6)/l (n = 51); Group 3 were HIV seropositive with CD4 + counts between 201 and 500 x 10(6)/l (n = 67); Group 4 were HIV seropositive with CD4+counts below 200 x 10(6)/l (n = 52) . Clinical signs and symptoms were noted and mid-stream specimens of urine obtained for culture and sensitivity . Overall 23% (50/222) had significant bacteriuria . The rates in each group respectively were 25%, 29%, 19% and 23% and there was no significant association between bacteriuria and HIV status; or between bacteriuria and level of immuno-suppression as indicated by CD4 + count . Overall 19% (30/222) of women had symptoms (frequency; dysuria; loin pain; smelly urine) or signs (fever; loin tenderness) compatible with urinary tract infection . However there was no significant association between symptoms or signs of infection and bacteriuria or HIV status . A typical range of pathogens, predominantly Enterobacteriaceae, were isolated and there were high rates of resistance to commonly used antimicrobials as well as 10% resistance to ciprofloxacin . Although high rates of significant bacteriuria can occur in highly sexually-active women, this appears unrelated to HIV infection or the level of HIV-related immunosuppression and is generally asymptomatic or clinically indistinct.

Zentralbl Bakteriol, 1996 Jul, 284(2-3), 255 - 62
Serological and biochemical properties of the major outer membrane protein within strains of the genus Actinobacillus; Hartmann L et al.; Sarcosyl-extracted outer membrane preparations of organisms of the genus Actinobacillus were investigated with regard to heat-modifiable and serological properties as well as N-terminal amino acid sequencing of the isolated major outer membrane protein (Omp) . The major Omp of Actinobacillus lignieresii was recognized by a monoclonal antibody with specificity towards Proteus mirabilis OmpA . Moreover, N-terminal amino acid sequencing revealed strong homology to OmpA of enterobacteriaceae, on the contrary, no reaction of the Proteus mirabilis OmpA monoclonal antibody was detectable when investigating the outer membrane preparations of Actinobacillus suis and Actinobacillus equuli in Western blot analyses . N-terminal amino acid sequencing of the major Omp of these two species showed homologies to OmpC or OmpF of the enterobacteriaceae . In accordance with these results, a polyclonal antibody with specificity for the major Omp of Pasteurella multocida cross-reacted with the major Omps of Actinobacillus suis and Actinobacillus equuli . The relationship of the major Omp of Pasteurella multocida and OmpC and OmpF had been verified in recent studies.

Zentralbl Bakteriol, 1996 Jul, 284(2-3), 207 - 17
The role of N-actylglucosaminyl-1,6 anhydro N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine for the induction of beta-lactamase in Enterobacter cloacae; Dietz H et al.; The mechanism of beta-lactamase induction in Enterobacter cloacae which is linked to the peptidoglycan recycling, was investigated by HPLC analysis of cell wall fragments in genetically defined cells . It is demonstrated here that the transmembrane protein AmpG transports not only the precursor muropeptide of M-tripeptide (N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid), the D-tripeptide (N-actylglucosaminyl-1,6 anhydro N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid), but also that of M-tetra-peptide (N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine), the D-tetrapeptide (N-actylglucosaminyl-1,6 anhydro N-acetylmuramyl-L-alanyl-D-glutamyl-meso-diaminopimelic acid-D-alanine), into the cytoplasm . These findings indicate that probably also M-tetrapeptide and D-tetrapeptide are signal muropeptides for beta-lactamase induction . In fact, D-tetrapeptide, not D-tripeptide, increases upon imipenem treatment.

Acta Chir Belg, 1996 Jul-Aug, 96(4), 165 - 7
Psoas abscess . A rare complication of Crohn's disease; Cools P et al.; Psoas abscess complicating Crohn's disease is a rare condition . Fever, abdominal tenderness, limb pain and hip contracture are typical signs but only present in half of the cases . Cultures of the pus mostly grow a mixture of enterobacteria . The diagnosis is made by CT-scan . Medical therapy always results in recurrence of the abscess . Resection of the fistula and the affected bowel segment with end-to-end anastomosis is the therapy of choice . A case report is presented, followed by a review of the literature.

Acta Paediatr, 1996 Jul, 85(7), 809 - 13
Concomitant bacteraemia as a risk factor for diarrhoeal disease mortality in Karachi: a case-control study of hospitalized children; Bhutta ZA et al.; The objective of this study was to evaluate risk factors for death due to diarrhoea among hospitalized children at the Aga Khan University Hospital (AKUH), Karachi . We conducted a retrospective case-control study of all diarrhoea deaths at AKUH over the period 1988-93 . For each death, the next two consecutive admissions matched for gender and type of diarrhoea were identified as controls . Data were analysed by univariate methods and logistic regression analysis . A total of 42 deaths and 84 matched controls were identified . Blood cultures at admission were obtained in all deaths and 94% of controls . The rates of isolation of organisms from blood cultures were significantly higher among deaths {38 versus 9%, odds ratio (OR) 6.5, 95% confidence interval (CI) 2.2-19.9}, the majority of which were Gram-negative Enterobacteriaceae (94 versus 57%, Fisher's exact test p < 0.02) . Conditional logistic regression revealed that several clinical and laboratory features of systemic infection were associated with a significantly increased risk of mortality, such as anorexia (OR 3.9, 95% CI 1.4-10.9), drowsiness (OR 4.4, 95% CI 1.3-15.3), respiratory distress (OR 7.0, 95% CI 1.4 36.6), anaemia (OR 5.8, 95% CI 2.0-16.6) and a positive blood culture (OR 8.7, 95% CI 2.5-30.7) . Our data suggest that bacteraemia with Enterobacteriaceae is common among hospitalized malnourished children with diarrhoea and systemic infection may be an important risk factor for mortality.

J Invertebr Pathol, 1996 Jul, 68(1), 65 - 73
Rapid Changes in Thermal Sensitivity of Entomopathogenic Nematodes in Response to Selection at Temperature Extremes
Grewal PS, Gaugler R, Shupe C.
Entomopathogenic nematodes (Rhabditida: Heterorhabditidae, Steinernematidae) are lethal insect parasites that have a symbiotic association with bacteria in the family Enterobacteriaceae . We evaluated the changes in thermal sensitivity of two nematodes Heterorhabditis bacteriophora and Steinernema anomali . The nematodes were genetically selected, together with their respective symbiotic bacteria, at nematodes' reproductive thermal niche breadth extremes, 15° and 30°C, by repeated passage through larvae of the wax moth Galleria mellonella . Nematode virulence (rate of insect mortality), establishment, and reproduction were evaluated after 12 passages (equal to 24-36 generations) . Direct and correlated responses of the selected strains were compared with the ancestral strains, maintained at 25°C, at the selection and novel temperatures . The thermal limits for virulence and establishment were extended in both species and at both selection regimes . The thermal reproductive niche breadth of H . bacteriophora was extended from 15°-30°C to 12°-32°C after selection at either 15° or 30°C, but that of S . anomali remained unchanged . Virulence of S . anomali was enhanced across the entire thermal niche breadth, but H . bacteriophora improved in one portion of the thermal niche and declined in another portion . Enhanced virulence of S . anomali was most likely due to the improvements in growth rate of the symbiotic bacteria, Xenorhabdus sp . Establishment of both species and reproduction of H . bacteriophora improved at most temperatures . S . anomali reproduction showed no direct response to temperature selection, but decrements and/or improvements were evident at novel temperatures . Our results demonstrate that the temperature-specific virulence and thermal niche breadth of entomopathogenic nematodes are malleable . Adaptation to either cold or warm temperature enhanced fitness in both cold and warm environments . S . anomali adapted to novel temperature by enhancing virulence, whereas H . bacteriophora improved fecundity . Trade-offs in fitness were rarely observed.

Antimicrob Agents Chemother, 1996 Jul, 40(7), 1729 - 32
Canadian ciprofloxacin susceptibility study: comparative study from 15 medical centers . Canadian Ciprofloxacin Study Group; Blondeau JM et al.; We tested 4,507 microorganisms, from 15 Canadian medical centers, against ciprofloxacin and several other antimicrobial agents to determine the in vitro susceptibilities . Overall, susceptibility of members of the family Enterobacteriaceae to ciprofloxacin was 97%; Moraxella and Haemophilus spp . had susceptibilities of 98 and 99%, respectively; and P . aeruginosa and S . aureus had susceptibilities of 79 and 96%, respectively.

J Clin Microbiol, 1996 Jul, 34(7), 1811 - 2
Evaluation of L-pyrrolidonyl peptidase paper strip test for differentiation of members of the family Enterobacteriaceae, particularly Salmonella spp; Inoue K et al.; The L-pyrrolidonyl peptidase activities of 1,033 strains of the family Enterobacteriaceae were investigated by the paper strip method to evaluate their usefulness for screening those organisms, especially Salmonella cultures . We also evaluated the usefulness of indole and tryptophan deaminase paper strip tests as supplements to the L-pyrrolidonyl peptidase test for the rapid identification of Salmonella cultures . The paper strip tests are simple, and the results are obtainable within 10 min.

J Struct Biol, 1996 Jul-Aug, 117(1), 73 - 6
Crystallization and preliminary X-ray diffraction analysis of UDP-N-acetylglucosamine enolpyruvyltransferase of Enterobacter cloacae; Sack S et al.; Single crystals of UDP-N-acetylglucosamine enolpyruvyltransferase of Enterobacter cloacae have been grown by vapor diffusion using phosphate buffer as the precipitant . The crystals belong to the monoclinic space group C2 with a = 86.9 A, b = 155.9 A, c = 83.8 A, beta = 91.6 degrees . Assuming two monomers per asymmetric unit, the solvent content of these crystals is 63% . Flash-frozen crystals diffract to beyond 2 A resolution.

Occup Environ Med, 1996 Jul, 53(7), 484 - 7
Bacterial and fungal flora of dust deposits in a pig building; Martin WT et al.; OBJECTIVE--The purpose of the study was to investigate the bacterial and fungal flora of dust deposits in a newly built pig grower finisher building . Viable bacterial counts and microbial species found in a barn which had never housed pigs were compared with those in a barn housing 144 pigs . METHODS--The quantitative streak plate method was used to measure viable bacterial counts on nutrient agar or sheep blood agar . Viable bacterial counts of the dust deposits were expressed as the number of colony forming units (CFUs)/mg of dust . Gram positive cocci and Gram negative bacilli were identified by an automated system . Identifications with a confidence interval > 90% were accepted at the species level . Fungi were identified to the genus level with slide culture preparations on cereal agar . RESULTS--The lowest viable bacterial count (4.8 x 10(4)/mg of dust) was found in the barn with no pigs . In the barn with pigs the highest viable bacterial count (2.1 x 10(6)/mg of dust) was in dust from the top of a partition close to pig activity . Six species of bacteria or fungi were found in dust from the room with no pigs, whereas 22 different microorganisms were detected in dust from the room with pigs . With the exception of Enterobacter agglomerans no other species of the family Enterobacteriaceae was found in dust deposits in this new pig building . Twelve species of Gram positive bacteria were found in the room housing pigs . CONCLUSIONS--The pig is not only a source but also a disperser of airborne bacteria in pig buildings . Speciation of the microbial flora in dust from the pig building suggests that many of the microorganisms were either of human or environmental origin . Nevertheless as some of these microorganisms are known opportunistic pathogens or allergens and because of the documented increased incidence of chronic respiratory symptoms in pig workers, precautions to reduce inhalation of microbial or dust particles by pig workers seem prudent.

Scand J Immunol, 1996 Jul, 44(1), 71 - 9
Bacteria-specific T-cell clones are selective in their reactivity towards different enterobacteria or H . pylori and increased in inflammatory bowel disease; Duchmann R et al.; In the present study the authors investigated the T-cell response to different enterobacteria or Helicobacter pylori and tested the hypothesis that the frequency of bacteria-specific T cells is increased in the intestine of patients with active inflammatory bowel disease (IBD), i.e . Crohn's disease (CD) and ulcerative colitis (UC) . The analysis of a large panel of T-cell clones (Tc) (n = 888) from peripheral blood, non-inflamed and inflamed intestine from IBD patients and control individuals shows that both peripheral blood and intestinal T-cell clones were selectively stimulated by either Salmonella typhimurium, Yersinia enterocolitica 03, Escherichia coli or Helicobacter pylori sonicates, that only < 3% of all bacteria-reactive Tc were crossreactive and that proliferation to bacterial sonicates was inhibited by anti-MHC class II antibody . In addition, bacteria-specific Tc from IBD patients were more frequently isolated from inflamed intestine than from peripheral blood (P = 0.0039) or non-inflamed intestine . These data, from a large number of T-cell clones, are the first systematic analysis describing the response of individual T cells towards different bacterial species (ssp.) . They show that T cells with specificity for distinct antigens or superantigens that are characteristic for a defined bacteria ssp . are present in normal, and increased in inflamed, IBD-intestine . These bacteria-specific Tc may play a role in IBD pathogenesis.

J Bacteriol, 1996 Jul, 178(13), 3962 - 6
A simple gel electrophoretic method for analyzing the muropeptide composition of bacterial peptidoglycan; Young KD; The muropeptide composition of bacterial peptidoglycan is currently most efficiently determined by reverse-phase high-pressure liquid chromatography (HPLC) . Though sensitive, the HPLC procedure is technically demanding and has been applied to a relatively small number of bacterial strains and species . We have found that fluorescence-assisted carbohydrate electrophoresis (FACE) is a simple, rapid method by which reducing muropeptides from multiple peptidoglycan samples can be visualized . Individual reducing muropeptides were covalently labeled with the fluorescent molecule 8-aminonaphthalene-1,3,6-trisulfonic acid, after which they were separated by electrophoresis through a 35% polyacrylamide gel and visualized by exposure to UV light . FACE detected the appropriate numbers of reducing muropeptides in the proper proportions for four bacteria: Escherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, and Yersinia enterocolitica . As little as 2 to 5 pmol per muropeptide was detected when the intensity of the fluorescent signal was measured with a charge-coupled device camera, at a level of sensitivity between 50 and 250 times higher than that of the classic HPLC technique . Thus, FACE may be used to identify interesting peptidoglycan samples prior to more-extensive analysis by HPLC, or FACE may eventually replace HPLC for some applications.

Lett Appl Microbiol, 1996 Jul, 23(1), 55 - 60
Repetitive element sequence-based PCR for species and strain discrimination in the genus Listeria; Jersek B et al.; Repetitive element sequence-based PCR (rep-PCR) was used to generate DNA fingerprints for Listeria spp . Two primer sets (REP 1R-I REP 2-I and ERIC 1R ERIC 2) used in respectively REP- and ERIC-PCR revealed that bacteria of the genus Listeria possess short repetitive extragenic palindromic elements and enterobacterial repetitive intergenic consensus sequences . Specific band profiles obtained by ERIC-PCR enabled the identification of Listeria species . With both REP- and ERIC-PCR the L . monocytogenes serotypes 1/2a, 1/2b, 1/2c, 3b and 4b could be clearly distinguished from each other . Within the serotype 1/2a, REP-PCR showed a higher discriminative potential than ERIC-PCR and a comparable discriminative potential as RAPD combining 3-4 primers.

Am J Med, 1996 Jun 24, 100(6A), 90S - 95S
Current and future management of serious skin and skin-structure infections; Schwartz R et al.; The purpose of this study was to compare in a randomized, open-label clinical study, the efficacy and safety of cefepime (1 g every 12 hours) with that of ceftazidime (1 g every 8 hours) in patients with serious skin and skin-structure infections . Of 298 patients enrolled in the study, 130 with serious skin and skin-structure infections were evaluable . Demographics and underlying medical conditions were comparable in both groups . The most common infections were cellulitis, abscesses, ulcers, and postoperative wound infections . The most common pathogens isolated were Staphylococcus aureus, group A streptococci, Enterobacteriaceae, and Pseudomonas aeruginosa . Duration of therapy in the 93 patients treated with cefepime was 3-18 days and in the 37 ceftazidime-treated patients was 4-16 days . Pathogen bacteriologic response rates were high: 92% (124 of 135) of pathogens were eradicated by cefepime and 95% (55 of 58) by ceftazidime . Clinical response rates were satisfactory in 88% (82 of 93) of cefepime-treated patients and in 89% (33 of 37) of ceftazidime-treated patients . Adverse events occurred with similar frequency in both groups . Events probably related to study drugs affected 3% (6 of 198) of patients treated with cefepime and 4% (4 of 100) of ceftazidime-treated patients . Cefepime, a new parenteral cephalosporin administered every 12 hours, is an extremely well tolerated and effective alternative to ceftazidime given every 8 hours for the treatment of serious skin and skin-structure infections.

Am J Med, 1996 Jun 24, 100(6A), 52S - 59S
Clinical applications of a new parenteral antibiotic in the treatment of severe bacterial infections; Holloway WJ et al.; Cephalosporins are one of the mainstays of antibiotic therapy, and third-generation cephalosporins are first-line agents for the treatment of many types of serious infections, including those of nosocomial origin . Gaps in activity of currently available third-generation cephalosporins such as cefotaxime, cefoperazone, ceftriaxone, and ceftazidime, and increasing reports of gram-negative bacilli resistance to some of these agents, especially Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterobacter spp., make it necessary to investigate new compounds . Cefepime, a fourth-generation cephalosporin with a wide range of activity against gram-positive and gram-negative bacteria, including multi-resistant strains of Enterobacteriaceae, was evaluated in comparison with ceftazidime for the treatment of serious infections in hospitalized patients . Ceftazidime is a commonly prescribed third-generation cephalosporin used for empiric treatment of serious infections such as pneumonia, urinary tract infection, and skin and skin-structure infection . This investigation was an open, randomized comparative study involving 882 patients in North America . Cefepime 2 g every 12 hours demonstrated similar efficacy to that of ceftazidime 2 g every 8 hours for the treatment of pneumonia and urinary tract infection (including cases associated with concurrent bacteremia), and skin and skin-structure infections . The bacteriologic responses were generally >85% . The most common pathogens isolated were Escherichia coll, Streptococcus pneumoniae, P . aeruginosa, K . pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and Streptococcus, group B . Overall, approximately 94% of pathogens isolated in pretreatment cultures were susceptible to cefepime and ceftazidime . Cefepime and ceftazidime were well tolerated; only 3% of patients in each group discontinued therapy because of an adverse event . The most common adverse events were headache, diarrhea, nausea, vomiting, pruritus, and rash . The results of this study indicate that cefepime is a promising, effective, and safe single-agent therapy for serious infections in hospitalized patients.

Am J Med, 1996 Jun 24, 100(6A), 3S - 12S
Impact of changing pathogens and antimicrobial susceptibility patterns in the treatment of serious infections in hospitalized patients; Jones RN; The selection of drug-resistant pathogens in hospitalized patients with serious infections such as pneumonia, urinary tract infections (UTI), skin and skin-structure infections, and primary or secondary bacteremia has generally been ascribed to the widespread use of antimicrobial agents . Issues of concern regarding gram-negative bacilli include the expression of extended spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumonias and constitutive resistance in some Enterobacteriaceae caused by Bush group 1 beta-lactamases . Current concerns with gram-positive pathogens are increasing multidrug resistance in methicillin-resistant Staphylococcus aureus, enterococci, and coagulase-negative staphylococci, and increasing incidence of penicillin-resistant Streptococcus pneumoniae . Contemporary treatment strategies for pneumonia in hospitalized patients mandate early empiric therapy for the most likely gram-positive and gram-negative pathogens . Newer beta-lactams, such as fourth-generation cephalosporins, may be useful in the treatment of pneumonia, including those cases associated with bacteremia . Combination beta-lactam/beta-lactamase inhibitor drugs, an aminoglycoside co-drug, or a carbapenem may also be indicated . The initial treatment of UTI in the hospital setting also may be empirically treated with the newer cephalosporins, combination broad-spectrum penicillins plus an aminoglycoside, a quinolone, or a carbapenem . Current problems in treating UTI include the emergence of extended spectrum beta-lactamase-producing Escherichia coli, the tendency of fluoroquinolones both to select for resistant strains of major UTI pathogens and to induce cross-resistance among different drug classes, and beta-lactam and vancomycin resistance of enterococci and coagulase-negative staphylococci . Treatment of skin and skin-structure infections is complicated by the coexistence of gram-positive and gram-negative infections, which may be drug resistant . Both fourth-generation beta-lactams and carbapenems may have in vitro activity against these pathogens; however, where these drugs--with their increased spectra and lower affinity for beta-lactamases and less susceptibility to beta-lactamase hydrolysis--fit into the therapeutic armamentarium remains to be determined . Initial clinical studies appear to be promising, nonetheless . The ability of both nosocomial and community-acquired pathogens to develop resistance to powerful broad-spectrum agents presents a great challenge for prescribing patterns and in the development of new drugs to be relatively resistant to inactivation.

Am J Med, 1996 Jun 24, 100(6A), 20S - 25S
Comparative susceptibilities of Klebsiella species, Enterobacter species, and Pseudomonas aeruginosa to 11 antimicrobial agents in a tertiary-care university hospital; Fekete T et al.; The in vitro activity of cefepime was compared versus that of 10 antimicrobial agents commonly used in the treatment of serious infections caused by common aerobic gram-negative bacteria: aztreonam, cefoperazone, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, piperacillin, ticarcillin-clavulanic acid, and tobramycin . We tested 30 clinical isolates representing a cross section of Klebsiella and Enterobacter species and Pseudomonas aeruginosa collected at our tertiary-care university hospital . The most potent beta-lactams were imipenem and cefepime, which demonstrated significant activity against the majority of strains in all 3 genera of bacteria tested, as did ciprofloxacin and tobramycin . Ceftazidime was active against Pseudomonas aeruginosa but was less potent against Klebsiella and Enterobacter spp . Cefoperazone and ceftriaxone were less active than ceftazidime against Pseudomonas aeruginosa . Cefepime was found to be highly active against many resistant organisms that traditionally have been difficult to treat.

Proc Natl Acad Sci U S A, 1996 Jun 11, 93(12), 5854 - 9
Similarities and dissimilarities of phage genomes; Blaisdell BE et al.; Genomic similarities and contrasts are investigated in a collection of 23 bacteriophages, including phages with temperate, lytic, and parasitic life histories, with varied sequence organizations and with different hosts and with different morphologies . Comparisons use relative abundances of di-, tri-, and tetranucleotides from entire genomes . We highlight several specific findings . (i) As previously shown for cellular genomes, each viral genome has a distinctive signature of short oligonucleotide abundances that pervade the entire genome and distinguish it from other genomes . (ii) The enteric temperate double-stranded (ds) phages, like enterobacteria, exhibit significantly high relative abundances of GpC = GC and significantly low values of TA, but no such extremes exist in ds lytic phages . (iii) The tetranucleotide CTAG is of statistically low relative abundance in most phages . (iv) The DAM methylase site GATC is of statistically low relative abundance in most phages, but not in P1 . This difference may relate to controls on replication (e.g., actions of the host SeqA gene product) and to MutH cleavage potential of the Escherichia coli DAM mismatch repair system . (v) The enteric temperate dsDNA phages form a coherent group: they are relatively close to each other and to their bacteria} hosts in average differences of dinucleotide relative abundance values . By contrast, the lytic dsDNA phages do not form a coherent group . This difference may come about because the temperate phages acquire more sequence characteristics of the host because they use the host replication and repair machinery, whereas the analyzed lytic phages are replicated by their own machinery . (vi) The nonenteric temperate phages with mycoplasmal and mycobacterial hosts are relatively close to their respective hosts and relatively distant from any of the enteric hosts and from the other phages . (vii) The single-stranded RNA phages have dinucleotide relative abundance values closest to those for random sequences, presumably attributable to the mutation rates of RNA phages being much greater than those of DNA phages.

Zentralbl Bakteriol, 1996 Jun, 284(1), 67 - 74
An economic approach to the MIC; Chapuis C et al.; The determination of the Inhibitory Concentration in Diffusion (ICD) is proposed as an alternative to the agar dilution Minimal Inhibitory Concentration (MIC) that is time-consuming and cumbersome for routine use . Based on the technique of the disk diffusion test, it consists in calculating a continuous variable, the ICD, corresponding to the antibiotic concentration in the agar at the edge of the inhibition zone . Six antibiotics were tested (ampicillin, cefotaxime, erythromycin, gentamicin, nalidixic acid and rifampicin) each against 17 to 51 strains of enterobacteria, Staphylococcus aureus and Enterococcus spp . and six other antibiotics (cefsulodin, ceftazidime, imipenem, piperacillin, ticarcillin and tobramycin), against 13 to 25 strains of Pseudomonas aeruginosa . A total of 284 antibiotic-strain combinations were tested . Three different antibiotic charges were obtained for each antibiotic by cutting commercial disks in two and four equal pieces . The ICD was calculated for each strain from the size of inhibition zones around a full disk, a half and a quarter of a disk . Concurrently, the MIC was performed, using a conventional agar dilution method . There was a good correlation between the two methods and reproducibility for the ICD proved to be correct . This reliable technique is very efficient both in terms of laboratory time and cost of materials and could be proposed for widespread use in clinical laboratories.

Childs Nerv Syst, 1996 Jun, 12(6), 318 - 22
Abscedation of posterior fossa dermoid cysts; Tekkok IH et al.; Dermoid cysts of the posterior fossa are uncommon . When associated with a dermal sinus, these cysts are often diagnosed during early childhood . The main risk of such an association is contamination of the cyst leading to abscedation of the dermoid itself or formation of daughter abscesses within the cerebellar hemisphere . We recently treated a 20-month-old girl who had a congenital dermal sinus leading to an intradural dermoid cyst . In addition to the midline dermoid cyst, computerized tomography revealed an enhancing lesion extending into the adjacent left cerebellar hemisphere . Suboccipital craniectomy was undertaken after 2 days of external ventricular drainage, and the infected dermoid and adjacent cerebellar abscess were excised . Cultures of the operative specimen revealed Corynobacterium aquaticum, Enterobacter sakazakii and Enterobacter cloacae, requiring 6 weeks of intravenous antibiotic therapy consisting of ceftriaxone, penicillin and gentamicin . A diligent literature search revealed only 24 sporadic cases reported over a period of 56 years . All 24 cases were in children (mean age 17 months), and one-third were in infants under the age of 1 year . All but 1 of these patients underwent posterior fossa surgery, with mortality and morbidity rates of 13% and 10%, respectively . Eleven (40%) children had suppuration within the cerebellar parenchyma, while the rest had abscedation of the dermoid cyst alone . Among the cases reviewed S . aureus was the most common agent, occurring with a probability of 64% . Key issues for appropriate management of these benign lesions are discussed.

FEMS Immunol Med Microbiol, 1996 Jun, 14(2-3), 129 - 34
Comparison of random amplified polymorphic DNA analysis and enterobacterial repetitive intergenic consensus-PCR for epidemiological studies of Salmonella; Millemann Y et al.; Discrimination of 70 Salmonella strains previously studied by ribotyping was realized by RAPD and ERIC-PCR analysis . RAPD results on the 56 S . typhimurium isolates did not closely match those of ribotyping . With ERIC-PCR, two fingerprints only were obtained . For the 14 S . enteritidis strains, a helpful discrimination was obtained with RAPD analysis, while ERIC-PCR resulted in a single fingerprint.

Clin Infect Dis, 1996 Jun, 22(6), 958 - 64
Chlamydia pneumoniae as a cause of community-acquired pneumonia in hospitalized patients in Berlin; Steinhoff D et al.; The incidence of community-acquired pneumonia due to Chlamydia pneumoniae was evaluated in a 1-year prospective study of 236 hospitalized patients with 237 manifestations of pneumonia . The microbiological diagnosis was based on results of cultures of blood and sputum or bronchoalveolar lavage fluid and results of complement fixation tests and indirect immunofluorescence of acute- and convalescent-phase sera for C . pneumoniae, Mycoplasma pneumoniae, Legionella species, Coxiella burnetii, and respiratory viruses . Diagnosis of acute C . pneumoniae infection was made on the basis of the results of microimmunofluorescence of paired serum samples . A microbiological diagnosis was obtained in 160 cases (67.5%) . C . pneumoniae was the causative agent in 27 patients (11.4%) . The following organisms were the other etiologic agents of pneumonia: Streptococcus pneumoniae, 30 cases (12.7%) (bacteremia occurred in 53.3%); Mycoplasma pneumoniae, 22 (9.3%); respiratory viruses, 22 (9.3%); and Enterobacteriaceae, 18 (7.6%) . The prevalence of C . pneumoniae antibody in our study population was 47.5% . As has been increasingly reported in recent years and confirmed by this study, C . pneumoniae appears to be a common etiologic agent of community-acquired pneumonia and upper respiratory tract infection in Germany.

Res Microbiol, 1996 Jun, 147(5), 393 - 403
Epidemiology of Salmonella enterica serotype Enteritidis infections in southern Italy during the years 1980-1994; Nastasi A et al.; Increased frequency of identification of Salmonella enterica serotype Enteritidis as a causative agent of sporadic and epidemic cases of infection in humans, along with isolation in many parts of the world of strains belonging in a large proportion to a few phage types, has made phage typing alone inadequate for epidemiological investigations . In southern Italy the epidemic increase in isolation of S . enterica serotype Enteritidis that has been observed since 1990 has been associated in approximately 80% of isolates with phage type 4 (PT-4), in agreement with the epidemiological observations from other European countries . We have applied polymerase chain reaction (PCR) ribotyping in association with phage typing to a sample of non-outbreak strains and to all the outbreak strains sent for identification and typing to the Southern Italy Centre for Enterobacterial Pathogens between 1980 and 1994 from hospital and public health laboratories . This technique identified 15 distinct profiles among the 405 strains examined . Whereas a single profile (PCR ribotype a1) appeared to be closely related to PT-8, and to characterize a high percentage of the strains circulating during the early non-epidemic years (1980-1985), 11 patterns were recognizable within PT-4, and 5 within PT-1 . Some of these apparently emerged after 1990 . This subdivision enabled attribution of the epidemic circulation of PT-4 to multiple clones of S . enterica serotype Enteritidis.

Pediatr Pol, 1996 Jun, 71(6), 523 - 7
{Analysis of blood of children hospitalized in the Children Memorial Health Institute between July 1992 and November 1995}; Lopaciuk U et al.; A total number of 6840 blood cultures were taken from 1753 patients hospitalized in the Children's Memorial Health Institute since 07.1992 to 11.1995 . Among 6840 blood samples 679 (10.2%) were culture positive and 745 microorganisms were detected; 83.5% Gram(+) bacteria, 9.1% Enterobacteriaceae rods, 1.6% nonfermenters, anaerobes - 3.1% and yeast 2.1% . Fifty two percent of all isolated strains were represented by CoNS . These bacteria were isolated mainly from children hospitalized in cardiology, cardiosurgery, neurosurgery, gastroenterology departments and dialysis unit . We found 68% methicillin resistant strains of CoNS . S . aureus was isolated from blood of children on parenteral nutrition, peritoneal fluid from patients on CAPD, and from blood of children with osteomyelitis/arthritis . Fourty percent of the S . aureus strains were methicillin resistant . Nonfermenters and Enterobacteriaceae rods were isolated predominantly from ICU and gastroenterology department . High percentage of these strains were multiresistant to various antibiotics: penicillins, I and II generations cephalosporins, aminoglycosides and others.

J Clin Microbiol, 1996 Jun, 34(6), 1512 - 8
Serological diagnosis of ovine enzootic abortion by comparative inclusion immunofluorescence assay, recombinant lipopolysaccharide enzyme-linked immunosorbent assay, and complement fixation test; Griffiths PC et al.; Since the 1950s, serological diagnosis of ovine enzootic abortion (OEA), caused by strains of Chlamydia psittaci, has been based mainly on the complement fixation test (CFT), which is neither particularly sensitive nor specific since antibodies to other chlamydial and enterobacterial pathogens may be detected . In this study . a recombinant enzyme-linked immunosorbent assay (rELISA) (medac, Hamburg, Germany), based on a unique chlamydial genus-specific epitope of Chlamydia trachomatis L2 lipopolysaccharide, was evaluated for sensitivity and specificity as a primary screening assay for OEA by comparison with the CFT . A comparative inclusion immunofluorescence assay (IFA), in which antibody titers to C . psittaci and Chlamydia pecorum were examined, was used as the reference test for 573 serum samples from four flocks . Reactivity to C . pecorum was measured since inapparent intestinal infections by C . pecorum are believed to be common in British flocks . In detecting positive sera from an abortion-affected flock, in which a C . pecorum infection was also suggested by IFA, the rELISA outperformed the CFT with significant evidence for increased sensitivity (P = 0.003) . In two flocks in which C . pecorum infections alone were suggested by IFA, the rELISA and CFT were prone to detect low levels of false-positive results, but the values were not significant . The rELISA provided results in one flock in which sera that were anticomplementary could not be resolved by the CFT . In another flock in which abortion had not occurred but infection by both chlamydial species was suspected, no significant difference was found between the sensitivities of the rELISA and CFT . The rELISA could not differentiate ovine C . psittaci and C . pecorum infections but was shown to be a more sensitive primary screening test for OEA than was the CFT, particularly where abortion had occurred and even when antibodies due to additional inapparent infection(s) by C . pecorum were present.

J Clin Microbiol, 1996 Jun, 34(6), 1474 - 80
Molecular epidemiology of Enterobacter aerogenes acquisition: one-year prospective study in two intensive care units; Davin-Regli A et al.; To evaluate the respective contributions of patient-to-patient transmission and endogenous acquisition of Enterobacter aerogenes isolates, we conducted a prospective epidemiologic study in two intensive care units (ICUs) between May 1994 and April 1995 . We collected a total of 185 E . aerogenes isolates: 130 from 51 patients in a surgical ICU (SICU), 45 from 26 patients in a medical ICU (MICU), and 10 from the environments in these two ICUs . All isolates were typed by random amplification of polymorphic DNA and enterobacterial repetitive intergenic consensus PCR . Among the 175 clinical isolate, we observed 40 different profiles by random amplification of polymorphic DNA and 36 different profiles by enterobacterial repetitive intergenic consensus PCR . We identified a ubiquitous and prevalent clone, corresponding to 58% of SICU and 41% of MICU clinical isolates . Three epidemiologically related strains were specific to each ICU and represented 17% of SICU and 24% of MICU clinical isolates; unique type strains represented 17 and 29% of SICU and MICU clinical isolates, respectively, and E . aerogenes strains which were spread to a limited degree and which were isolated less than five times during the 1-year study period represented 8 and 6% of SICU and MICU clinical isolates, respectively . Our results show that E . aerogenes is acquired in the ICU in three different ways: patient-to-patient spread of a prevalent or an epidemiologically related strain, acquisition de novo of a strain from patients' own flora, and acquisition of a nonendemic strain followed by occasional patient-to-patient transmission . The findings point out the importance of patient-to-patient transmission in E . aerogenes acquisition and suggest that changes in E . aerogenes ecology in the hospital have taken place during the past decade.

Antimicrob Agents Chemother, 1996 Jun, 40(6), 1564 - 8
In vitro and in vivo evaluations of LB20304, a new fluoronaphthyridone; Oh JI et al.; In vitro activity of LB20304 against 1,231 clinical isolates was evaluated and compared with those of ciprofloxacin, sparfloxacin, lomefloxacin, and ofloxacin . LB20304 demonstrated the most potent activity against gram-positive bacteria . It was 32- to 64-fold more active than ciprofloxacin against methicillin-susceptible Staphylococcus aureus, methicillin-resistant S . aureus, methicillin-resistant Staphylococcus epidermidis, and Streptococcus pneumoniae (penicillin G resistant) . LB20304 was also highly active against most members of the family Enterobacteriaceae . Its activity was more potent than those of sparfloxacin, ofloxacin, and lomefloxacin and comparable to that of ciprofloxacin . The protective activities of LB20304 against systemic infections caused by gram-positive bacteria in mice were superior to those of ciprofloxacin and sparfloxacin . Against infections by gram-negative bacteria, LB20304 was slightly less active than ciprofloxacin.

Diabetes Care, 1996 Jun, 19(6), 638 - 41
Diabetic foot infections . Bacteriology and activity of 10 oral antimicrobial agents against bacteria isolated from consecutive cases; Goldstein EJ et al.; OBJECTIVE: To study the relative frequency of bacterial isolates cultured from community-acquired foot infections and assess their comparative in vitro susceptibility to sparfloxacin, levofloxacin, and eight other commonly used oral antimicrobial agents . RESEARCH DESIGN AND METHODS: This is a prospective study in which the infected wounds of 25 consecutive diabetic patients seen by one of the authors were cultured as they entered the hospital . Isolates were stored and tested for susceptibility to 10 oral antimicrobial agents using the agar dilution method . RESULTS: Staphylococcus aurcus was the most common isolate (76% of patients), including methicillin-resistant S . aurcus (MRSA) in 5 of 25 (20%) patient wounds . Streptococci, enterococci, Enterobacteriaceae, and anaerobes were also present in > or = 40% of patient wounds . Sparfloxacin and levofloxacin were the most active agents tested with activity against > or = 88% of isolates . Isolates resistant to sparfloxacin and levofloxacin included MRSA, enterococci, and some anaerobes . When analyzed by prior exposure to antibiotics, patients who had previously received oral antibiotics were more likely to have MRSA, enterococci, and Pseudomonas aeruginosa isolated and less likely to have Enterobacteriaceae and anaerobes isolated from their wounds . CONCLUSIONS: MRSA and enterococci are now a common cause of diabetic foot infections, and the increased prevalence may be due to antimicrobial use . These wounds may require use of combined antimicrobial therapy for initial outpatient management . The new fluoroquinolones, sparfloxacin and levofloxacin, were the most active oral agents tested.

Lett Appl Microbiol, 1996 Jun, 22(6), 393 - 6
The survival benefit of short-chain organic acids and the inducible arginine and lysine decarboxylase genes for Escherichia coli; Guilfoyle DE et al.; The short-chain organic acids (SCOAs), acetic and propionic acids, are used widely as food preservatives . The production of these two acids plus butyric acid in the colon by anaerobes serves as a mechanism for controlling the numbers of enterobacteria (which can be pathogens) in this organ . It has been found in this study that the acid tolerance of cells initially grown at near neutral pH (6.5) to a lethal pH of 3.5 is enhanced by their exposure to 0.1% propionate or butyrate . The data also indicate that the inducible arginine and lysine decarboxylases are important for the survival of Escherichia coli exposed to a combination of mildly acidic pH (5.5) and 0.5% butyrate . This study suggests that the presence of SCOAs could trigger an adaptive survival response which may be important in the survival of food-borne pathogens.

Ann Rheum Dis, 1996 Jun, 55(6), 363 - 9
Role of enteric bacteria in the pathogenesis of rheumatoid arthritis: evidence for antibodies to enterobacterial common antigens in rheumatoid sera and synovial fluids; Aoki S et al.; OBJECTIVE: To study antibodies to Escherichia coli O:14, which expresses large amounts of enterobacterial common antigen (ECA), and their corresponding antigen molecules in serum and synovial fluid samples from patients with rheumatoid arthritis (RA) . METHODS: Enzyme linked immunosorbent assay (ELISA) was used to measure antibodies to heat killed E coli O:14 in serum and synovial fluid samples from patients with RA and control subjects including healthy donors and patients with osteoarthritis . ELISA was also used to perform absorption analyses of antibodies to E coli O:14 with several enteric bacteria and their lipopolysaccharide (LPS) . In addition, antigenic molecules reacting with E coli O:14 antibodies from patients with RA were examined using immunoblot analysis and N-terminal amino acid analysis . RESULTS: Compared with control subjects, patients with RA showed significantly increased titres of antibodies against heat killed E coli O:14 in 33 of 83 serum samples (39.8%) and 38 of 58 joint fluid samples (65.5%) . Absorption analyses with enteric bacteria and their LPS resulted in the reduction of antibody titres to heat killed E coli O:14 in serum and synovial fluid samples from the RA patients . In addition, immunoblot analysis of the samples from RA patients revealed not only a ladder-like banding pattern equivalent to ECA associated with LPS, but also two clear bands of bacterial outer membrane proteins of 35 kDa (Omp A) and 38 kDa (Omp C), having amino acid sequence homology with those of other Enterobacteriaceae . CONCLUSION: These results suggest that some patients with RA are sensitised to antigens common to Enterobacteriaceae, and this may prove relevant to the future development of immunotherapy for RA . Furthermore, this sensitisation to antigens found commonly in Enterobacteriaceae may have a key role in the pathogenesis of human RA similar to that described previously in our animal model.

Infect Immun, 1996 Jun, 64(6), 2019 - 23
Identification of a domain in Rck, a product of the Salmonella typhimurium virulence plasmid, required for both serum resistance and cell invasion; Cirillo DM et al.; Rck is encoded on the Salmonella typhimurium virulence plasmid and is a member of a family of related 17- to 19-kDa outer membrane proteins of Enterobacteriaceae, including Ail (Yersinia enterocolitica) and PagC (S . typhimurium) . Structural models for these proteins predict eight membrane-spanning domains alternating with hydrophilic inner and outer loops . When expressed in Escherichia coli, Rck and Ail, but not PagC, confer high-level resistance to the bactericidal activity of complement as well as the ability to adhere to and invade mammalian cell lines . To identify functional domains of Rck, we made and screened random mutations in Rck for decreased bioactivity . We found that a single amino acid substitution (glycine to aspartic acid) in the putative third outer loop greatly reduced Rck-mediated serum resistance and eukaryotic cell invasion . We then constructed two chimeric proteins between Rck and PagC . Substitution of the C-terminal half of Rck with the corresponding PagC fragment containing both the third and the fourth outer loops abolishes the Rck-mediated serum resistance and invasion phenotypes . Substitution of Rck with a smaller C-terminal portion of PagC containing the fourth outer loop did not affect the invasive phenotype or serum resistance . These data reveal that the third putative outer membrane loop region is important for the virulence-associated properties of the Rck protein and suggest a similarity between the mechanism of serum resistance and epithelial cell invasion involving the same domain of Rck.

FEMS Microbiol Lett, 1996 Jun 1, 139(2-3), 229 - 34
Characterization of a novel SHV beta-lactamase variant that resembles the SHV-5 enzyme; Prinarakis EE et al.; An SHV type beta-lactamase frequently found in enterobacteria isolated in Greek hospitals was analyzed . The enzyme (SHV-5a) conferred resistance to ceftazidime and aztreonam . The DNA sequence of the structural gene was determined . The deduced amino acid sequence showed that positions 70-73 were occupied by the active site tetrad Ser-Thr-Phe-Lys . As in SHV-5, Ser-238 and Lys-240 were present . However, one deletion (Gly-54) and three substitutions (Arg-140 for Ala, Asn-192 for Lys and Val-193 for Leu) differentiate SHV-5a beta-lactamase from SHV-5 . Asn-192 and Val-193 have been reported to date only in the R974 plasmid-mediate SHV-1 beta-lactamase . Hydrolysis studies with SHV-5a and SHV-5 showed that the enzymes behaved similarly . Additional evidence that they are functionally indistinguishable was provided by the similar MICs of beta-lactams when the enzymes were expressed under isogenic conditions . The sequence differences, however, indicate that they are derived from different ancestors.

Am J Clin Pathol, 1996 Jun, 105(6), 774 - 81
Clinical evaluation of the BacT/Alert and isolator aerobic blood culture systems; Engler HD et al.; The BacT/Alert (BTA) (Organon Teknika, Durham, NC) and Isolator 10 (ISO) (Wampole Laboratories, Cranbury, NJ) blood culture systems were evaluated for their ability to detect aerobic and facultatively anaerobic microorganisms in blood of adult patients . For each culture 8 mL of blood was inoculated into both the aerobic standard BTA bottle and the ISO tube . Of 7,259 paired culture sets, 1,168 organisms were recovered, and 667 (57.1%) of these were considered clinically significant . This represented 540 clinically significant positive cultures from 266 patients . Of the significant isolates, 410 were recovered by both systems, 108 by BTA only and 149 by ISO only (P <.025) . Overall, the BTA detected 77.7% of the significant isolates, whereas ISO detected 83.8% . The ISO recovered significantly more isolates of Staphylococcus aureus (P = .0001), coagulase-negative Staphylococcus spp (P <.01), and non-Enterobacteriaceae gram-negative rod species (P <.0025), whereas the BTA detected significantly more isolates of Streptococcus spp (P <.0025) . Growth of S aureus (P <.0025), Enterococcus spp (P <.0025), and Streptococcus spp (P <.0075) was detected earlier by the BTA when laboratory coverage was available during the first shift only (7:30 AM to 4:00 PM), and additionally of Enterobacteriaceae (P <.0005) and other gram-negative rod species (P <.0001) if coverage was extended to 12:00 AM . Yeasts were detected more rapidly by the ISO (P <.0025) . The ISO contamination rate (5.9%) was six times that of the BTA . Taking into account its ability to rapidly detect most organisms, its automated and thus labor-saving features, and the minimal contamination rate associated with its use, the BTA appears to be a reliable alternative to the ISO as a blood culturing system, although improvement in detection of staphylococci and non-Enterobacteriaceae gram-negative rods would be desirable.

J Mol Biol, 1996 May 10, 258(3), 447 - 56
Distribution of restriction enzyme recognition sequences on broad host range plasmid RP4: molecular and evolutionary implications; Wilkins BM et al.; IncP alpha plasmids, exemplified by RP4, are remarkable for their broad host range . They contain strikingly few cleavage sites for many commonly used type II restriction enzymes but an overabundance of sites for certain enzymes that target G + C-rich sequences . To identify factors responsible for these distributions, the recently compiled nucleotide sequence of RP4 was analysed to determine the frequency of tetra- and hexanucleotide motifs in the 49 kb plasmid backbone . This is defined as the sectors encoding basic plasmid functions . The overabundant restriction targets in RP4 are concentrated in the backbone and contain overlapping copies of CGGC/GCCG, identified as the most abundant tetranucleotide motif in the plasmid . Motif frequencies in the RP4 backbone are shown to be similar to those in Pseudomonas aeruginosa, a natural host of RP4, with the notable exception that a number of 6-bp palindromes are underrepresented in the plasmid . It is proposed that 6-bp palindromes were counterselected as type II restriction enzyme recognition sequences . Conjugative transfer of RP4 and R751 (IncP beta) is unusually sensitive to restriction compared to enterobacterial plasmids of the IncFII and IncI1 groups, implying that IncP plasmids experienced particularly strong selection for loss of restriction targets . Pseudomonas spp . of rRNA homology group I specify many type II restriction enzymes that target 6-bp palindromes and are candidates for the evolutionary hosts of IncP alpha plasmids.

Nature, 1996 May 2, 381(6577), 77 - 80
Mast cell modulation of neutrophil influx and bacterial clearance at sites of infection through TNF-alpha; Malaviya R et al.; Although mast cells have been implicated in a variety of inflammatory conditions including immediate hypersensitivity and interstitial cystitis, their physiological role in the body is unknown . We investigated the role of mast cells in host defence against bacterial infections using a well characterized mast-cell-deficiency mouse model . We report here that mast cells, which are selectively located at portals of bacterial entry, are important to host defence . Mast-cell-deficient WBB6F1-W/Wv mice (W/Wv) were up to 20-fold less efficient in clearing enterobacteria than control WBB6F1 +/+ (+/+) mice or mast-cell-reconstituted W/Wv (W/Wv+MC) mice . With higher bacteria inocula, only W/Wv mice died (80%) . The limited bacterial clearance in W/Wv mice directly correlated with impaired neutrophil influx . The mast-cell chemoattractant TNF-alpha was implicated in the neutrophil response because TNF-alpha was locally released only in +/+ and W/Wv+MC mice, TNF-alpha-specific antibodies blocked over 70% of the neutrophil influx, and purified mast cells released TNF-alpha upon incubation with bacteria . Additionally, the type-1 fimbrial subunit, FimH, was the necessary enterobacterial component for mast-cell activation and neutrophil influx because an isogenic FimH- mutant evoked a limited neutrophil response in +/+ mice compared to wild-type bacteria.

Genetica, 1996 May, 97(3), 363 - 78
How is osmotic regulation of transcription of the Escherichia coli proU operon achieved? A review and a model; Gowrishankar J et al.; The proU operon in enterobacteria encodes a binding-protein-dependent transporter for the active uptake of glycine betaine and L-proline, and serves an adaptive role during growth of cells in hyperosmolar environments . Transcription of proU is induced 400-fold under these conditions, but the underlying signal transduction mechanisms are incompletely understood . Increased DNA supercoiling and activation by potassium glutamate have each been proposed in alternative models as mediators of proU osmoresponsivity . We review here the available experimental data on proU regulation, and in particular the roles for DNA supercoiling, potassium glutamate, histone-like proteins of the bacterial nucleoid, and alternative sigma factors of RNA polymerase in such regulation . We also propose a new unifying model, in which the pronounced osmotic regulation of proU expression is achieved through the additive effects of at least three separate mechanisms, each comprised of a cis element {two promoters P1 and P2, and negative-regulatory-element (NRE) downstream of both promoters} and distinct trans-acting factors that interact with it: stationary-phase sigma factor RpoS with P1, nucleoid proteins HU and IHF with P2, and nucleoid protein H-NS with the NRE . In this model, potassium glutamate may activate proU expression through each of the three mechanisms whereas DNA supercoiling has a very limited role, if any, in the osmotic induction of proU transcription . We also suggest that proU may be a virulence gene in the pathogenic enterobacteria.

J Appl Bacteriol, 1996 May, 80(5), 465 - 70
Control of microbiological quality and shelf-life of catfish (Clarias gariepinus) by chemical preservatives and smoking; Efiuvwevwere BJ et al.; Fresh catfish (Clarias gariepinus) were subjected to different concentrations of sodium benzoate or potasium sorbate and smoked traditionally before evaluation for microbiological, chemical and organoleptic characteristics during ambient tropical storage . Unsmoked fish samples showed diverse microflora (Enterobacter, Escherichia, Serratia, Bacillus, Staphylococcus, Streptococcus, Penicillium, Aspergillus and Achlya genera) while smoked samples were dominated by Gram-positive bacterial flora (Bacillus, Staphylococcus and Streptococcus) and spoilage moulds (Penicillium verrucosum, Aspergillus flavus and Achlya spp.) . Significant reduction in microbial population occurred in most samples following smoking with samples subjected to 0.4% (w/v) potassium sorbate showing the lowest microbial load and maximum shelf-stability . However, marked microbial increase occurred after day 4 of storage in control and benzoate-treated samples . Changes in pH were marginal but decreased after day 12 of storage . Moisture content decreased sharply after smoking and remained low after day 4 of storage . Overall, potassium sorbate treatment (0.4% w/v) was most effective in controlling microbial quality and extended the shelf-life of the samples by 8 d.

Mikrobiol Z, 1996 May-Jun, 58(3), 94 - 103
{Species of enterobacteria new to medicine}; Pokhil SI; The paper presents main biological characteristics of six new species of enterobacteria, which may cause a number of infectious processes in man: Moellerella wisconsensis, Koserella trabulsii . Leclercia adecarboxylata . Escherichia fergusonii . Rahnella aquatilis, Enterobacter asburiae . The characteristics presented allow the bacteriologists of the laboratory of health services to isolate and to identify the above-mentioned enterobacteria.

Mikrobiol Z, 1996 May-Jun, 58(3), 38 - 44
{The cellular fatty acid composition of bacteria in the family Vibrionaceae}; Vasiurenko ZP et al.; It is shown that strains of Vibrio cholerae of serovar O1, biovar eltor, subtype Ogawa, museum strains V . cholerae of serovar O1 and NAG-vibrios (isolated from various sources: sea, river and sewage water, canal water and people) possess identical composition of cell fatty acids with prevailing hexadecenoic, hexadecanoic and octadecenoic acids . Being identical, fatty acid profiles of V . parahaemolyticus and V . alginolyticus, are close to that of V . cholerae differing from the latter mainly by the higher content of dodecanoic acid . Similarity of Aeromonas sp . and Vibrio strains in the fatty acid composition proves phylogenetic relation-ship of these bacteria . Fatty acid composition of Plesiomonas shigelloides cells characterized by the presence of methylenhexadecanoic acid as well as by similarity with Vibrio and Aeromonas by the content of most fatty acids confirms a supposition of R . R . Colwell on the intermediate status of genus Plesiomonas between the families Enterobacteriaceae and Vibrionaceae . Independent of the growth medium, the strains Vibrio . Aeromonas and Plesiomonas preserved a fatty-acid profile, inherent in them, with variations mainly in the content of fatty acids with the odd number of carbon atoms . Allowing for relative stability of fatty acid composition and its peculiarity in certain taxonomic groups of the studied bacteria, the above test may be used as additional objective criterion to identify the representatives of Vibrionaceae family.

Mol Microbiol, 1996 May, 20(4), 725 - 39
The hmu locus of Yersinia pestis is essential for utilization of free haemin and haem--protein complexes as iron sources; Hornung JM et al.; Yersinia pestis strains utilize haem and several haem-protein complexes as sole sources of iron . In this study, the haemin uptake locus (hmu) of Y . pestis KIM6+ was selected from a genomic library by transduction into an Escherichia coli siderophore synthesis (entC) mutant . Recombinant plasmids containing a common 16 kb BamHI insert were isolated that allowed E . coli entC to use haemin as an iron source . An 8.6 kb region of this insert was found to be essential for haemin utilization and encoded at least five proteins with molecular masses of 79/77, 44, 37, 35, and 30/27.5 kDa . A 10.9 kb Clal fragment containing the hmu locus showed varying degrees of homology to genomic DNA from Yersinia pseudotuberculosis, Yersinia enterocolitica, and other genera of Enterobacteriaceae . An E . coli hemA aroB strain harbouring cloned hmu genes used haemin as both an iron and porphyrin source but only on iron-poor medium, suggesting that haemin uptake is tightly iron regulated . Additionally, haemoglobin and myoglobin were used as iron sources by an E . coli entC (pHMU2.2) strain . Deletion of the hmu locus from Y . pestis KIM6+ chromosome generated a mutant that grew poorly on iron-depleted medium containing free haemin as well as mammalian haem-protein complexes including haemoglobin, haemoglobin-haptoglobin, myoglobin, haem-haemopexin, and haem-albumin unless it was complemented with cloned hmu genes.

FEMS Immunol Med Microbiol, 1996 May, 14(1), 25 - 9
Molecular epidemiological tools for Salmonella Dublin typing; Kerouanton A et al.; A total of 32 strains of Salmonella Dublin recovered from cattle were differentiated by electrophoretic typing of their esterases (zymotyping), restriction fragment length polymorphism of ribosomal DNA (ribotyping), arbitrarily primed PCR (AP-PCR) using five primers, PCR based on repetitive extragenic palindromic sequences (REP-PCR) and PCR based on enterobacterial repetitive intergenic consensus sequences (ERIC-PCR) . ERIC-PCR and REP-PCR each gave one type, zymotyping gave three, AP-PCR gave five and ribotyping gave seven types . Combination of ribotyping and AP-PCR produced a total of 11 types, whereas 14 different types were obtained by all five methods . Thus a combination of several methods enhanced the discrimination of cattle-adapted strains among the genotypically homogeneous serovar Salmonella Dublin.

Cent Afr J Med, 1996 May, 42(5), 147 - 50
Prevalence, antimicrobial properties and beta-lactamase production of haemolytic enterobacteria in patients with diarrhoea and urinary tract infections in Legos, Nigeria; Kesah CN et al.; OBJECTIVE: To determine the prevalence, antimicrobial properties and beta-lactamase production of haemolytic enterobacteria in patients with diarrhoea and urinary tract infections in Lagos, Nigeria . DESIGN: Hospital based prospective study . SUBJECTS: Total of 324 patients comprising 194 diarrhoeal and 130 urinary tract infection (UTI) cases . MAIN OUTCOME MEASURES: Production of haemolysms . beta-lactamase and antibiograms of isolates . RESULTS: 186 (57.41 pc) of the 324 clinical specimens screened were positive for enterobacteria, out of which 29 (15.59 pc) were haemolytic . Proteus vulgaris (2.78 pc) Klebsiella spp . (1.85pc) . Escherichia coli (1.23 pc) . Pseudomonas spp . (0.93 pc) . Yersinia enterocolitics and Morganella morganii (0.62 pc) . Salmonella spp . Vibrio cholerae and Proteus mirabilis (0.31pc) were the haemolytic enterobacteria Isolated . The susceptibilities of haemolytic bacteria to eight antibotics determined by disc-agar diffusion technique revealed that all 29 (100 pc) haemolytic isolates were sensitive to gentamycin and streptomycin but showed varied susceptibilities to the other drugs . Eleven (37.9 pc) of the 29 isolates produced beta-lactamase . CONCLUSION: We conclude that gentamycin and streptomycin are effective drugs against haemolytic isolates from diarrhoea and UTI cases.

Zh Mikrobiol Epidemiol Immunobiol, 1996 May-Jun, (3), 91 - 3
{The anticomplement activity of the commercial strain of Bacillus cereus IP 5832 and of enterobacteria when cocultured}; Brudastov IuA et al.; Bacillus cereus production strain IP 5832 of the preparation "Bactisubtil" has been characterized with respect to its anticomplementary activity (ACA) and the parameters of its heterogeneity in the process of adaptation to trypticase-soybean medium and during cultivation in anaerobic conditions have been determined . The cultivation of B.cereus strain IP 5832 jointly with Escherichia coli, Enterobacter cloacae and Klebsiella pneumoniae strains, isolated in enteric disbiosis, affects ACA in different ways, which leads to structural changes in the populations of these enterobacteria, characterized by an increase of their heterogeneity with respect to ACA.

Zh Mikrobiol Epidemiol Immunobiol, 1996 May-Jun, (3), 88 - 90
{The antilysozymal activity and species characteristics of the microflora of the female reproductive tract during pregnancy}; Cherkasov SV et al.; The results of the study of the species composition and the antilysozyme activity of the microflora the reproductive tract of pregnant women are presented . Changes in the microflora of the reproductive system of pregnant women have been registered . These changes are characterized by the increased proportion of staphylococci in biotopic samples of the reproductive tract and the isolation of enterobacterial strains with high antilysozyme activity.

Zh Mikrobiol Epidemiol Immunobiol, 1996 May-Jun, (3), 84 - 6
{The effect of drug preparations on the expression of the persistence properties of uropathogenic strains of enterobacteria}; Chelpachenko OE et al.; The results of experiments on the study of the influence of antibiotics, agents used in pathogenetic therapy and phytopreparations on the persistence properties of uropathogenic bacteria have demonstrated that medicinal remedies produce different effects on the persistence factors of microorganisms (inhibiting, stimulating, neutral) . The method of the selection of optimum medicinal remedies inhibiting the persistence factors of bacteria with the aim of ensuring the effective therapy of pyelonephritis has been developed.

Res Microbiol, 1996 May, 147(4), 297 - 309
Evaluation of an expert system linked to a rapid antibiotic susceptibility testing system for the detection of beta-lactam resistance phenotypes; Vedel G et al.; Interpretive reading of antibiotic disc agar diffusion tests indicates the resistance mechanisms, if any, expressed by a bacterium . An expert system for determining resistance mechanisms using rapid automated antibiotic susceptibility tests has been developed . The beta-lactam susceptibility of each of 300 strains of clinically significant species of enterobacteria, displaying natural and acquired resistance mechanisms, was determined by disc agar diffusion and by a rapid automated method of susceptibility testing associated with an expert system . For every strain, the conclusion of the expert analysis of the automated test was compared with the commonly accepted interpretation of disc agar diffusion tests . Of the 300 strains studied, 275 were similarly interpreted (91.7% agreement) . The susceptible and naturally beta-lactam-resistant phenotypes (wild phenotypes) were equally recognized by both methods . Similarly, the results of the two methods concurred for most of the acquired resistance phenotypes . However, for 25 strains (8.3%) the results diverged . The expert system proposed an erroneous phenotype (5 strains), several phenotypes including the correct one (17 strains), or no phenotype (1 strain) . For 2 strains the natural resistance mechanism was not detected at first by the automated method but was subsequently deduced by the expert analysis according to bacterial identification . These results demonstrate that satisfactory interpretive reading of automated antibiotic susceptibility tests is possible in 4 to 5 hours but requires careful selection of the antibiotics tested as phenotypic markers.

Jpn J Antibiot, 1996 May, 49(5), 509 - 16
{Antibacterial activities of combination uses of isepamicin and beta-lactams in vitro against clinically isolated strains . Part 3 . The results against Pseudomonas aeruginosa}; Deguchi K et al.; We investigated antibacterial activities of combination uses of isepamicin (ISP) and beta-lactams in vitro against Pseudomonas aeruginosa, and the following conclusions were obtained . 1 . ISP + piperacillin, ISP + ceftazidime, ISP + aztreonam, ISP + imipenem and ISP + panipenem against P . aeruginosa showed strong combined effects . 2 . The minimum inhibitory concentrations (MICs) of these combinations were low and dependent on concentrations of ISP . And strong antibacterial activities were observed at ISP concentrations of sub-MIC levels . These results were similar to the results of previous reports, parts 1 and 2 . 3 . Concentrations of ISP sufficient to lower MIC90 values when by combined with beta-lactam agents were 4 approximately 8 micrograms/ml . These effects made it possible to lower the ISP dose to 400 mg at a single dose and the enhancement of activities by combinations resulted in strong antibacterial activities against multiple drug resistant stains at sub-MIC levels of ISP . Strong antibacterial activities were also obtained against beta-lactams-resistant strains of ISP-susceptible strains when ISP was combined with beta-lactam agents . 4 . All results reported in parts 1 approximately 3 indicated that no antagonisms were produced by combining ISP + penicillins, ISP + cephems, ISP + monobactams and ISP + carbapenems against Staphylococcus aureus, Enterobacteriaceae and P . aeruginosa . These combinations showed strong antibacterial activities that were enhanced synergistically with wider spectra.

Am J Health Syst Pharm, 1996 May 1, 53(9), 1024 - 7
Serum bactericidal activity of ceftizoxime and ceftriaxone against pathogens associated with community-acquired and nosocomial pneumonias; Belliveau PP et al.; The serum bactericidal activities of ceftizoxime and ceftriaxone against organisms commonly implicated in community-acquired and nosocomial pneumonias were studied . Ceftizoxime 1 g (as the sodium salt) every 12 hours for two doses and ceftriaxone 1 g (as the sodium salt) every 24 hours for two doses were administered to 20 healthy volunteers in a crossover fashion . Blood samples were drawn immediately before and 2,4,6,8,10, and 12 hours after the second ceftizoxime dose and immediately before and 8,12,16,18,20, and 24 hours after the second ceftriaxone dose . Serum drug concentrations were determined by validated high-performance liquid chromatography . Serum bactericidal titers were determined in duplicate for each serum sample against four clinical isolates of each of the following organisms: Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Serratia marcescens . The median duration of serum bactericidal activity during the dosage interval was significantly different between antimicrobial regimens only for S . pneumoniae (92% of the dosage interval for ceftizoxime, versus 100% for ceftriaxone) . This difference does not appear to be clinically important since ceftizoxime provides adequate serum bactericidal activity for more than 50% of the dosage interval and its effectiveness against pneumococcal pneumonia has been supported in clinical trials . The ceftriaxone and ceftizoxime regimens did not differ significantly in their duration of serum bactericidal activity against six of the seven organisms tested.

Pathology, 1996 May, 28(2), 167 - 72
An evaluation of the in vitro activity of piperacillin/tazobactam; Daley D et al.; Tazobactam is a new, irreversible inhibitor of bacterial beta-lactamases of staphylococci, plasmid-mediated beta-lactamases of the TEM and SHV types found in Escherichia coli and Klebsiella species and beta-lactamases of anerobes such as Bacteroides species . Its combination with piperacillin, a broad spectrum ureido-penicillin, would be expected to improve the activity of piperacillin against staphylococci, TEM and SHV beta-lactamase producing Gram negative bacteria and anerobes . Minimal inhibitory concentrations (MIC) of piperacillin/tazobactam were determined for 1952 individual patient isolates of Gram positive and negative bacteria causing significant infections and compared with MIC values for cefotaxime, ceftazidime, ciprofloxacin, imipenem, ticarcillin/clavulanic acid . MICs were determined by agar dilution (NCCLS 1990 and 1992) . Piperacillin/tazobactam had excellent activity against methicillin susceptible staphylococci, Streptococcus pneumoniae, Haemophilus influenzae, enterococci and organisms of the Bacteroides fragilis group . It was also active against the majority of Enterobacteriaceae and Pseudomonas aeruginosa isolates tested . It was not active against extended spectrum beta-lactamase (ESBL) producing Klebsiella species and some high level TEM and SHV beta-lactamase producing E . coli and Klebsiella species . Activity against Gram negative organisms capable of producing chromosomally mediated beta-lactamases was good, since in most organisms tested, the enzymes were not induced in sufficient quantities to cause antibiotic resistance . However some Enterobacter species were derepressed hyperproducing mutants; these isolates showed resistance to piperacillin/tazobactam since tazobactam does not inhibit these Class I beta lactamases . Activity was superior to ticarcillin/clavulanic acid for Gram negative rods . Imipenem was the most active agent against ESBL producing Klebsiella species . Piperacillin/tazobactam has a suitable spectrum of activity in vitro to suggest its use in monotherapy of mixed anerobic infections, mixed respiratory infections such as aspiration pneumonia and, in combination with an aminoglycoside, it would provide Gram positive as well as Gram negative cover of febrile episodes in immunosuppressed patients.

J Antimicrob Chemother, 1996 May, 37 Suppl A, 135 - 44
Comparative efficacy of sparfloxacin versus ciprofloxacin in the treatment of complicated urinary tract infection; Naber KG et al.; A total of 686 adult patients with complicated urinary tract infections were enrolled in a double-blind, randomised, multicentre study to compare sparfloxacin (200 mg loading dose on day 1 followed by 100 mg daily) with ciprofloxacin (500 mg orally twice daily) for 10 to 14 days . Urinary tract infection was defined as pyuria and bacteriuria (cfu > or = 10(5)/mL) . Evaluations were performed at four time-points . The clinical efficacy of the two antibacterial agents was equivalent at the end of treatment: clinical cure in 88.6% of the intent-to-treat population and 87.3% in the evaluable population treated with sparfloxacin compared to 85.4% and 84.8% of the intent-to-treat and evaluable populations, respectively, treated with ciprofloxacin . The clinical results were also equivalent at follow-up . The bacteriological efficacy of the two agents was not equivalent . At the end of treatment, bacteriological cure was observed in 72.6% of the intent-to-treat and 72.1% of the evaluable populations treated with sparfloxacin and in 81.4% and 80.8% of the intent-to-treat and evaluable populations, respectively, treated with ciprofloxacin . The difference was primarily because of a higher number of persisting pathogens, which included Enterobacteriaceae other than Escherichia coli, Pseudomonas aeruginosa and enterococci, which exhibited moderate susceptibility to sparfloxacin . Tolerability was similar in the two treatment groups.

J Clin Microbiol, 1996 May, 34(5), 1299 - 302
Polymorphism in Brucella strains detected by studying distribution of two short repetitive DNA elements; Mercier E et al.; Thirty-four Brucella reference or field strains representing all the species and biovars were studied by repetitive element sequence-based PCR, a PCR using primers complementary to two enterobacterial short repetitive sequences: repetitive extragenic palindromic and enterobacterial repetitive intergenic consensus sequences . All the stains showed a positive amplification, suggesting that the Brucella genome contains such sequences . Repetitive extragenic palindromic PCR was less discriminating than enterobacterial repetitive intergenic consensus PCR in terms of distinguishing strains, but a combination of the two methods was able to distinguish all the isolates, except for some strains belonging to biovars 3 and 9 of Brucella abortus . Repetitive element sequence-based PCR appears to be a simple and useful method for the study of brucellosis epidemiology.

Infect Control Hosp Epidemiol, 1996 May, 17(5), 281 - 5
Gram-negative bacteremia in open-heart-surgery patients traced to probable tap-water contamination of pressure-monitoring equipment; Rudnick JR et al.; OBJECTIVE: To determine the cause(s) of an outbreak of gram-negative bacteremia (GNB) in open-heart-surgery (OHS) patients at hospital A . DESIGN: Case-control and cohort studies and an environmental survey . RESULTS: Nine patients developed GNB with Enterobacter cloacae (6), Pseudomonas aeruginosa (5), Klebsiella pneumoniae (3), Serratia marcescens (2), or Klebsiella oxytoca (1) following OHS; five of nine patients had polymicrobial bacteremia . When the GNB patients were compared with randomly selected OHS patients, having had the first procedure of the day (8 of 9 versus 12 of 27, P = .02), longer cardiopulmonary bypass (median, 122 versus 83 minutes, P = .01) or cross-clamp times (median, 75 versus 42 minutes, P = .008), intraoperative dopamine infusion (9 of 9 versus 15 of 27, P = .01), or exposure to scrub nurse 6 (6 of 9 versus 4 of 27, P = .001) were identified as risk factors . When stratified by length of the procedure, only being the first procedure of the day and exposure to scrub nurse 6 remained significant . First procedures used pressure-monitoring equipment that was assembled before surgery and left open and uncovered overnight in the operating room, whereas other procedures used pressure-monitoring equipment assembled immediately before the procedure . At night, operating rooms were cleaned by maintenance personnel who used a disinfectant-water solution sprayed through a hose connected to an automatic diluting system . Observation of the use of this hose documented that this solution could have contacted and entered uncovered pressure-monitoring equipment left in the operating room . Water samples from the hose revealed no disinfectant, but grew P aeruginosa . The outbreak was terminated by setting up pressure-monitoring equipment immediately before the procedure and discontinuing use of the hose-disinfectant system . CONCLUSIONS: This outbreak most likely resulted from contamination of uncovered preassembled pressure-monitoring equipment by water from a malfunctioning spray disinfectant device . Pressure-monitoring equipment should be assembled immediately before use and protected from possible environmental contamination.

Antimicrob Agents Chemother, 1996 May, 40(5), 1289 - 93
Differences in the resistant variants of Enterobacter cloacae selected by extended-spectrum cephalosporins; Fung-Tomc JC et al.; The rates of development of resistance to ceftriaxone, ceftazidime, cefepime, and cefpirome in 10 strains of Enterobacter cloacae were determined by daily transfer for 7 days to fresh medium containing twofold serial dilutions of the antibiotics . Development of resistance to ceftriaxone was the most rapid; this was followed by ceftazidime, cefpirome, and cefepime . Resistant variants selected by ceftriaxone and ceftazidime were cross-resistant and produced very high levels of beta-lactamase . On the other hand, resistant variants selected by cefepime and cefpirome often had moderately high levels of beta-lactamase and diminished levels of the 39- to 40-kDa porin protein.

S Afr Med J, 1996 May, 86(5), 542 - 5
Intravenous immunoglobulin prophylaxis in neonates on artificial ventilation; Adhikari M et al.; The efficacy of the prophylactic use of intravenous immunoglobulin (Ig) was evaluated in a double-blind placebo-controlled trial of 21 pairs of ventilated neonates weighing more than 1,500 g . Each infant received 0.4 g/kg/day of intravenous Ig or a similar volume of placebo daily for 5 days . Criteria used to assess the efficacy of intravenous Ig were the number of infections, the duration of ventilation therapy and time to clinical recovery . There were no significant differences in the treated and placebo groups with regard to the frequency of positive blood cultures (28.6% and 14.3%), endotracheal cultures (57.1% and 66.7%) and abnormal white cell counts (52.4% and 57.1%) . On entry to the study there was no significant difference in IgG levels between the treated (974.5 mg/dl; SD 575.3) and placebo groups (818 mg/dl; SD 516.9) . However, on day 6 the treated group had a mean level of 1,400.3 mg/dl (SD 426.7) versus 710.9 mg/dl (SD 377.4) in the placebo group (P < 0.05) . Clinical improvement occurred within 3 days in both groups . Ventilatory support was required for 11.8 days (SD 8.3) in the treated and 11.8 days (SD 7.3) in the placebo group . Both groups required 3-4 antibiotic treatments over a period of 14-15 days . Two patients died in the treated and 4 in the placebo group, with 1 infant in each group developing bronchopulmonary dysplasia . The patients who recovered did so within 14 days . Analyses of subgroups of patients with different diagnoses revealed no differences except a trend suggesting fewer infections in term babies treated with intravenous Ig . The organisms cultured in the intravenous Ig groups were Pseudomonas, Klebsiella, Escherichia coli and Staphylococcus and in the placebo group Pseudomonas, Klebsiella and Enterobacter . The above has shown that, except for a trend in the older neonates, intravenous Ig is not of prophylactic benefit in ventilated neonates . Newer adjuncts in immunotherapy such as hyperimmune gammaglobulin or monoclonal antibodies may prove of greater value in the treatment of neonatal sepsis.

Clin Diagn Lab Immunol, 1996 May, 3(3), 351 - 4
A monoclonal antibody reactive with a common epitope of Moraxella (Branhamella) catarrhalis lipopolysaccharides; Oishi K et al.; A hybrid cell line producing a monoclonal antibody (MAb) against Moraxella (Branhamella) catarrhalis lipopolysaccharide (LPS) was established . The specificity of the MAb 1B12 to purified rough LPSs from six strains of M . catarrhalis was ascertained by enzyme-linked immunosorbent assay (ELISA), competitive-inhibition ELISA, and immunoblotting . MAb 1B12 bound to live bacterial cells and culture supernatants from a total of 34 strains of M . catarrhalis, including 12 strains with different LPS serotypes . No cross-reactions with smooth and rough LPSs from selected enterobacterial and nonenterobacterial strains, with other respiratory pathogens, or with Neisseria species were observed . These data suggest that MAb 1B12 recognizes a common epitope of M . catarrhalis LPS which differs from serotype determinants.

Clin Diagn Lab Immunol, 1996 May, 3(3), 309 - 14
Characterization of a monoclonal antibody specific for Brucella smooth lipopolysaccharide and development of a competitive enzyme-linked immunosorbent assay to improve the serological diagnosis of brucellosis; Weynants V et al.; The reactivity of monoclonal antibody (MAb) 12G12 was analyzed in regard to the main biovars of Brucella species and some members of the families Enterobacteriaceae and Vibrionaceae which present serological cross-reactions with the smooth lipopolysaccharide (S-LPS) of Brucella species . This MAb was strictly directed against the common specific epitope of the Brucella S-LPS . It recognized all of the smooth Brucella strains and biovars except B . suis biovar 2 . In order to improve the specificity of the serological diagnosis of brucellosis, a competitive enzyme-linked immunosorbent assay (cELISA) was developed with the horseradish peroxidase-conjugated MAbs 12G12 and S-LPS of B . melitensis Rev1 . The specificity of the cELISA was analyzed with 936 serum samples from healthy cattle . The assay was evaluated with sera from heifers (n = 18) experimentally infected with B . abortus 544 . After infection, the performance of the cELISA was in agreement with those of the complement fixation test and the rose Bengal plate test . Finally, the specificity of the assay was also evaluated in regard to false-positive serological reactions by using sera from heifers experimentally infected with Yersinia enterocolitica 0:9 (n = 4) and with field sera presenting false-positive reactions (n = 74) . The specificity of the cELISA was greater than the specificities of the complement fixation test and the rose Bengal plate test . Indeed, the new assay detected only 31 of the 101 false-positive serum samples detected by at least one serological test.

Microbiology, 1996 May, 142 ( Pt 5), 1133 - 40
Actin-related proteins in Anabaena spp . and Escherichia coli; Guerrero-Barrera AL et al.; Actin has been described in all eukaryotic cells as the major microfilament cytoskeletal protein . Although prokaryotic cells do not have a cytoskeleton, proteins related to the latter have been found in different prokaryotic species . We have found prokaryotic actin-related proteins in the enterobacterium Escherichia coli and in the cyanobacteria Anabaena cylindrica and Anabaena variabilis . They were identified by the following criteria: (1) by cross-reaction with a fluorescent conjugated anti-actin (rat-brain) mAb by Western blot analysis (in total cellular extracts); (2) specific binding of acetone powder and soluble cellular extracts to DNase I; and (3) specific binding of cells and total cellular extracts to phalloidin . In E coli, specific binding of phalloidin labelled with rhodamine to cells was detected by spectrofluorometry . In total cellular extracts, three bands of 60, 43 and 35 kDa were weakly recognized by the mAb by Western blot analysis; this recognition increased when phalloidin was added to the extracts . Furthermore, three polypeptides of kDa were isolated by binding to DNase I, showing pI values of 6.7, 6.65 and 6.6, less acidic than all reported actin pI values . In A . cylindrica and A . variabilis, specific binding of phalloidin labelled with rhodamine to cells was also detected by spectrofluorometry . In total and soluble cellular extracts, the mAb recognized two bands of 45 and 40 kDa by Western blot analysis, but only the first was purified by binding to DNase I, and it showed three isoforms of pI values 6.8, 6.5 and 6.4 . These results suggest the presence, in prokaryotes, of proteins with similar biochemical characteristics to eukaryotic actin.

Biochem J, 1996 May 1, 315 ( Pt 3), 745 - 51
The role of residues glutamate-50 and phenylalanine-496 in Zymomonas mobilis pyruvate decarboxylase; Candy JM et al.; Several enzymes require thiamine diphosphate (ThDP) as an essential cofactor, and we have used one of these, pyruvate decarboxylase (PDC; EC 4.1.1.1) from Zymomonas mobilis, as a model for this group of enzymes . It is well suited for this purpose because of its stability, ease of purification, homotetrameric subunit structure and simple kinetic properties . Crystallographic analyses of three ThDP-dependent enzymes {Muller, Lindqvist, Furey, Schulz, Jordan and Schneider (1993) Structure 1, 95-103} have suggested that an invariant glutamate participates in catalysis . In order to evaluate the role of this residue, identified in PDC from Zymomonas mobilis as Glu-50, it has been altered to glutamine and aspartate by site-directed mutagenesis of the cloned gene . The mutant proteins were expressed in Escherichia coli . Here we demonstrate that substitution with aspartate yields an enzyme with 3% of the activity of the wild-type, but with normal kinetics for pyruvate . Replacement of Glu-50 with glutamine yields an enzyme with only 0.5% of the catalytic activity of the wild-type enzyme . Each of these mutant enzymes has a decreased affinity for both ThDP and Mg2+ . It has been reported that the binding of cofactors to apoPDC quenches the intrinsic tryptophan fluorescence {Diefenbach and Duggleby (1991) Biochem . J . 276, 439-445} and we have identified the residue responsible as Trp-487 {Diefenbach, Candy, Mattick and Duggleby (1992) FEBS Lett . 296, 95-98} . Although this residue is some distance from the cofactor binding site, it lies in the dimer interface, and the proposal has been put forward {Dyda, Furey, Swaminathan, Sax, Farrenkopf and Jordan (1993) Biochemistry 32, 6165-6170} that alteration of ring stacking with Phe-496 of the adjacent subunit is the mechanism of fluorescence quenching when cofactors bind . The closely related enzyme indolepyruvate decarboxylase (from Enterobacter cloacae) has a leucine residue at the position corresponding to Phe-496 but shows fluorescence quenching properties that are similar to those of PDC . This suggests that the fluorescence quenching is due to some perturbation of the local environment of Trp-487 rather than to a specific interaction with Phe-496 . This latter hypothesis is supported by our data: mutation of this phenylalanine to leucine, isoleucine or histidine in PDC does not eliminate the fluorescence quenching upon addition of cofactors.

Biochemistry, 1996 Apr 16, 35(15), 4923 - 8
Characterization of a Cys115 to Asp substitution in the Escherichia coli cell wall biosynthetic enzyme UDP-GlcNAc enolpyruvyl transferase (MurA) that confers resistance to inactivation by the antibiotic fosfomycin; Kim DH et al.; The antibiotic fosfomycin inhibits bacterial cell wall biosynthesis by inactivation of UDP-GlcNAc enolpyruvyl tranferase (MurA) . Prior work has established that Cys115 of Escherichia coli and Enterobacter cloacae MurA is the active site nucleophile alkylated by fosfomycin and implicated this residue in the formation of a covalent phospholactyl-enzyme adduct derived from substrate, phosphoenolpyruvate (PEP) . On the basis of sequencing information from putative MurA homolog from Mycobacterium tuberculosis, we generated a C115D mutant of E . coli MurA that was highly active but fully resistant to time-dependent inhibition by fosfomycin . Fosfomycin still bound to the active site of C115D MurA, as established by the observed reversible competitive inhibition by fosfomycin . Fosfomycin still bound to the active site of C115D MurA, as established by the observed reversible competitive inhibition vs PEP . In contrast to the broad pH-independent behavior of wild-type (WT) MurA, C115D mutant activity titrated across the pH range examined (pH 5.5-9) with an apparent pKa approximately 6, with kcatC115D ranging from approximately 10kcatWT at pH 5.5 to <0.1kcatWT at pH9.0 . Km(PEP)115D was relatively constant in the pH range examined and increased approximately 100-fold relative to Km(PEP)WT . A fosfomycin-resistant C115E mutant with -1% activity of the C115D mutant was found to follow a pH dependence similar to that observed for C115D MurA . The contrasting pH dependences of WT and C115D MurA was also observed in the reaction with the pseudosubstrate, (Z)-3-fluorophosphoenolpyruvate, strongly suggesting a role for Cys/Asp115 as the general acid in the protonation of C-3 of PEP during MurA-catalyzed enol ether transfer . The difference in nucleophilicity between the carboxylate side chains of Asp115 and Glu115 and the thiolate group of Cys115 suggests that covalent enzyme adduct formation is not required for catalytic turnover and, furthermore, provides a chemical rationale for the resistance of the C115D and C115E mutants to fosfomycin inactivation.

Science, 1996 Apr 5, 272(5258), 107 - 9
Asymmetries generated by transcription-coupled repair in enterobacterial genes; Francino MP et al.; Although certain replication errors occur at different frequencies on each of the complementary strands of DNA, it remains unclear whether this bias is prevalent enough during chromosome replication to affect sequence evolution . Here, nucleotide substitutions in enteric bacteria were examined, and no difference in mutation rates was detected between the leading and lagging strands, but in comparing the coding and noncoding strands, and excess of C-->T changes was observed on the coding strand . This asymmetry is best explained by transcription-coupled repair on the noncoding strand . Although the vast majority of mutations are thought to arise from spontaneous errors during replication, this result implicates DNA damage as a substantial source of mutations in the wild.

Infect Control Hosp Epidemiol, 1996 Apr, 17(4), 222 - 6
Loss of antimicrobial susceptibility in aerobic gram-negative bacilli repeatedly isolated from patients in intensive-care units; Manian FA et al.; OBJECTIVE: To study the loss of antimicrobial susceptibility in repeat (same patient, same bacterial species, and same site) aerobic gram-negative bacilli (AGNB) isolated from individual patients during their stay in the intensive-care unit (ICU) . SETTING: A 792-bed, tertiary-care community hospital with a total of 107 adult, pediatric, and neonatal ICU beds . METHOD: An observational prospective study performed November 1992 through mid-July 1993 . RESULTS: Of 594 consecutive AGNB from 287 ICU patients, 117 isolates (20%) from 55 patients (19%) were repeat isolates, with the majority obtained from respiratory secretions (83%) . Pseudomonas aeruginosa and Enterobacter species accounted for 61% of the isolates . Forty-two (36%) of the repeat isolates from 24 patients (44%) had > or = 4-fold increase in minimum inhibitory concentration to at least one antibiotic and no longer were considered fully susceptible based on National Committee on Clinical Laboratory Standards criteria . Loss of antimicrobial susceptibility often developed within several (median 8) days and was associated only infrequently with simultaneous transition from colonization to infection in the individual patient . Use of certain beta-lactam antibiotics was associated with increasing resistance to several other antibiotics in the same class . Concurrent use of beta-lactams and aminoglycosides did not prevent loss of antimicrobial susceptibility to the former in repeat isolates . CONCLUSION: We conclude that loss of antimicrobial susceptibility in repeat AGNB isolated from ICU patients is common, usually is not associated with transition from colonization to infection, and often is associated with prior use of antibiotics . Minimizing antibiotic use in ICU patients should help reduce the risk of antimicrobial resistance in repeat AGNB isolates.

Appl Environ Microbiol, 1996 Apr, 62(4), 1214 - 9
Degradation of pentaerythritol tetranitrate by Enterobacter cloacae PB2; Binks PR et al.; A mixed microbial culture capable of metabolizing the explosive pentaerythritol tetranitrate (PETN) was obtained from soil enrichments under aerobic and nitrogen-limiting conditions . A strain of Enterobacter cloacae, designated PB2, was isolated from this culture and was found to use PETN as a sole source of nitrogen for growth . Growth yields suggested that 2 to 3 mol of nitrogen was utilized per mol of PETN . The metabolites pentaerythritol dinitrate, 3-hydroxy-2,2-bis-{(nitrooxy)methyl}propanal, and 2,2-bis-{(nitrooxy)methyl}-propanedial were identified by mass spectrometry and 1H-nuclear magnetic resonance . An NADPH-dependent PETN reductase was isolated from cell extracts and shown to liberate nitrite from PETN, producing pentaerythritol tri- and dinitrates which were identified by mass spectrometry . PETN reductase was purified to apparent homogeneity by ion-exchange and affinity chromatography . The purified enzyme was found to be a monomeric flavoprotein with a M(r) of approximately 40,000, binding flavin mononucleotide noncovalently.

Hum Exp Toxicol, 1996 Apr, 15(4), 329 - 34
Bacterial reduction of N-oxides of tobacco-specific nitrosamines (TSNA); Atawodi SE et al.; 1 . Contrary to established metabolic pattern, a recent investigation of NNK metabolism produced in rat urine higher levels of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) than their N-oxides, suggesting that reconversion of N-oxides could occur after urine formation . 2 . To verify the possible role of bacteria in the reduction of NNK-N-oxide and NNAL-N-oxide to their respective parent compounds, NNK and NNAL, in smokers with urinary tract infection (UTI), the N-oxides were isolated from the urine of rats treated with {5-3H}NNK and individually incubated at 37 degrees C with ten bacterial species in sterile human urine under different pH regimens . After incubation with the bacteria, aliquots of culture media were analyzed by high pressure liquid chromatography (HPLC) with radiochemical detection . 3 . Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae and Proteus mirabilis possessed varying capacity to regenerate NNK and NNAL from their N-oxides while others showed no detectable reductive capability within 24 h . 4 . This result constitutes the first experimental evidence that in tobacco users with concomitant UTI, bacterial regeneration of the procarcinogenic NNK and NNAL from their N-oxides could occur in the bladder leading to increased carcinogen burden in these individuals.

Diagn Microbiol Infect Dis, 1996 Apr, 24(4), 191 - 6
Clinical comparison of the BACTEC 9000 Standard Anaerobic/F and Lytic/F blood culture media; Hollick GE et al.; An 8-month prospective, volume controlled, comparison of Standard Anaerobic/F media with a new anaerobic high blood volume lytic medium (Lytic/F) was performed . A total of 2,092 compliant sets, consisting of an aerobic resin bottle or standard aerobic bottle, Standard Anaerobic/F, and Lytic/F bottle were evaluated . A total of 220 (10.6%) positive specimens were detected from the paired anaerobic bottles . These consisted of 194 true positive and 26 false positive bottles . Of 207 total organisms isolated, 122 were considered clinically significant . A comparison of significant organism recovery revealed 79 isolates in both anaerobic bottles, 7 isolates in the standard Anaerobic/F bottle only, and 36 isolates in the Lytic/F bottle only (p < 0.001) . The lytic/F bottle detected significantly more Enterobacteriaceae (p < 0.005) and Streptococci (p < 0.05) . There were 24 false positive Standard Anaerobic/F bottles and 2 false positive Lytic/F bottles (p < 0.001) . When both bottles were positive the Standard Anaerobic/F bottle was positive 12 hours earlier in 1 instance whereas the Lytic/F bottle was positive 12 hours earlier in 8 instances . The mean time for detection in the Standard Anaerobic/F bottle was 18.2 hours versus 13.2 hours for the Lytic/F bottle . The new Lytic/F anaerobic blood culture media was found to be superior to Standard Anaerobic/F media for both total organism recovery and time to organism detection.

Int J Food Microbiol, 1996 Apr, 29(2-3), 297 - 309
Influence of unsliced delicatessen meat freshness upon bacterial growth in subsequently prepared vacuum packed slices; Holley RA et al.; Unsliced beef pastrami, reformulated ham and bologna held at 6 degrees C were sliced 21, 17, 12 or 7 days before or at the assigned manufacturer's best before date and vacuum packaged . Packages of sliced meats were held at 6 degrees C for another 7, 12, 17 or 21 days, opened and analyses made for total bacteria, lactic acid bacteria, Enterobacteriaceae and Brochothrix thermosphacta . The maximum storage interval was 42 days; half this period unsliced, the remainder as repacked slices . Numbers of bacteria on pastrami were significantly greater than on ham and bologna (pastrami > ham > bologna) with the lactic acid bacteria dominating in all products . As unsliced meats approached their best before date, insignificant increases were generally noted for numbers of lactic bacteria, Enterobacteriaceae and B . thermosphacta . During subsequent storage of slices under vacuum, numbers of total and lactic bacteria increased exponentially at the same rate while B . thermosphacta growth was significantly slower . Numbers of Enterobacteriaceae remained low and were essentially unchanged during sliced meat storage . Within the context of study storage parameters, shelf-life appeared to be determined by length of time after slicing and repackaging rather than by best before date of the unsliced meat . Packages of sliced meat prepared from wholesale unsliced meats with 21 days left until their best before date or from unsliced meats with 12 days left until the best before date showed similar bacterial levels 21 days later . It was probable that the localization of bacterial growth at the meat surface-packaging film interface of the unsliced meats yielded slices with initially lowered bacterial content when repackaged and sampled from the uppermost slice . When Enterobacteriaceae and B . thermosphacta were absent from unsliced meats, extension of sliced meat package shelf-life beyond the best before date of the parent meat was possible . However, these bacterial groups were not always undetected.

Eur J Clin Microbiol Infect Dis, 1996 Apr, 15(4), 281 - 5
Predominant pathogens found in the European Prevalence of Infection in Intensive Care Study; Spencer RC; A one-day point prevalence of infection analysis was undertaken in 1417 intensive care units (ICUs) (10,038 patients) in 17 western European countries . The prevalence of ICU-acquired infection was 20.6% (2064 patients), representing almost half the cases of infection . Pneumonia was the most commonly reported infection (46.9%), followed by infection of the lower respiratory tract (17.8%), urinary tract (17.6%), and blood (13.0%) . Staphylococcus aureus was the most frequently isolated organism (30.1%), followed by Pseudomonas aeruginosa (28.7%), coagulase-negative staphylococci (19.1%), yeasts (17.1%), and enterococci (11.7%) . As a group, the Enterobacteriaceae were the most commonly isolated organisms (34.4%) . The study also revealed that resistance to antimicrobial agents is common among Staphylococcus aureus, Pseudomonas aeruginosa, and coagulase-negative staphylococci.

Mol Cell Probes, 1996 Apr, 10(2), 117 - 22
Polymerase chain reaction of bacterial genomes with single universal primer: application to distinguishing mycobacteria species; Bahrmand AR et al.; The polymerase chain reaction with a single universal primer (UP-PCR) was applied to bacterial strains and mycobacteria isolates alongside conventional methods . A universal protocol of preparation of PCR samples from cultures representing Escherichia coli, Enterobacter aerogenes, Serratia marcescens, Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Mycobacterium tuberculosis, Mycobacterium bovis, and several non-tuberculous mycobacteria was found to be reproducible and efficient with these organisms . The bands of UP-PCR products observed in an agarose gel after electrophoresis were species-specific and provided an efficient means of distinguishing bacterial species . The applicability of this approach to mycobacteria identification was assessed by comparing the DNA bands obtained for different strains . Three reference strains and 22 clinical isolates of M . tuberculosis and M . bovis produced very similar DNA banding patterns . They comprised a triplet of prominent and several minor fragments within the 200-500 base pair (bp) size range and were the easiest to interpret . The DNA profiles of unrelated mycobacteria clearly differed from each other when subjected to electrophoretic analysis and correlated well with results of culture method . The method provides a real promise of its application in clinical studies as a simple assay for distinguishing between tubercle bacilli.

J Chemother, 1996 Apr, 8(2), 122 - 9
Piperacillin/tazobactam in the treatment of hospitalized patients with urinary tract infections: an open non-comparative and multicentered trial; Sifuentes-Osornio J et al.; The aim of this multicentered, prospective and open study was to determine the clinical and bacteriological efficacy and safety of piperacillin/tazobactam (4g/500 mg IV tid) in the treatment of 79 adult patients with complicated urinary tract infections (UTI) requiring hospitalization . Forty-seven women and 32 men (mean age 54.2 years, and range 21-91) from 4 Argentinean and 6 Mexican hospitals were enrolled . Sixty-one clinically and bacteriologically evaluable patients were treated for a mean of 9.1 days (range 5-15) . A favorable clinical response was seen in 83.6% and 80% at early and late assessment, respectively . Bacteriological eradication was achieved in 85.3% and 80% at early and late estimation, respectively . Escherichia coli was isolated in 33 cases, Klebsiella pneumoniae in 8, Enterococcus spp . in 7, Proteus mirabilis in 6, Pseudomonas aeruginosa in 3, Enterobacter spp . and Morganella morganii in 2 . While 21% of all the clinical isolates were resistant to piperacillin, none of them was initially resistant to piperacillin/tazobactam . However, one female patient with a persistent UTI caused by E . coli developed resistance to piperacillin/tazobactam during treatment . A 64-year-old man with frontal meningioma developed purulent meningitis due to Enterobacter cloacae after neurosurgery . He was initially treated with ciprofloxacin, rifampin and amikacin and because of persistence of fever, he was moved to piperacillin/tazobactam . After 5 days of therapy, he developed coma secondary to intracranial hemorrhage and died . By then, the platelet count was normal (220,000/microliters), but the prothrombin time (19.5 seconds) and the partial thromboplastin time (63 seconds) were significantly prolonged . Our data suggest that piperacillin/tazobactam is a reliable therapy for complicated, non-complicated, community or hospital-acquired UTI.

Aust Vet J, 1996 Apr, 73(4), 137 - 40
Equine neonatal septicaemia: 24 cases; Raisis AL et al.; Equine neonatal septicaemia was confirmed in 24 foals hospitalised at the Rural Veterinary Centre between 1989 and 1992 with suspected septicaemia . Septicaemia was confirmed by culture of bacteria from blood of live foals and tissues obtained at necropsy of foals that died or were euthanased . Pathogenic bacteria isolated were predominantly Enterobacteriaceae (including Escherichia coli and Salmonella serovars) and Actinobacillus equuli . Clinical manifestations of septicaemia included signs of depression, dehydration, abnormalities in body temperature and manifestations of localised infection including diarrhoea, pneumonia, and septic arthritis . Most common haematological abnormalities were neutropenia and increase of circulating band neutrophils . Survival rate of foals with confirmed septicaemia was 70.8% . Survival was found to be less likely in the presence of pneumonia, severe signs of depression, marked haematological changes or septic arthritis at the time of admission . Seven foals were confirmed to have septic arthritis without concurrent septicaemia . Of these, 4 had multiple joint involvement . Bacteria isolated from infected joints were predominantly Salmonella serovars . Four foals with septic arthritis failed to survive, due to multiple joint infection, which was unresponsive to treatment . The clinical and haematological abnormalities present in foals with confirmed septicaemia and septic arthritis were consistent with those observed in other studies . The bacterial isolates from foals with confirmed septicaemia were similar to those isolated in other studies . In contrast, the bacteria isolated from foals with septic arthritis without concurrent septicaemia were different from other studies.

Br J Rheumatol, 1996 Apr, 35(4), 359 - 63
Prediction of diagnosis in acute and subacute oligoarthritis of unknown origin; Kvien TK et al.; A total of 146 consecutive patients between 18 and 60 yr of age with oligoarthritis of unknown origin (< or = 6 active joints, < or = 8 weeks duration) were examined by a variety of clinical, laboratory and microbiological investigations, and followed longitudinally for 24 weeks . Reactive arthritis was diagnosed in 46 patients (19 induced by Chlamydia trachomatis, 27 by enterobacteria), 62 had undifferentiated arthritis, eight other inflammatory arthritic diseases, 15 acute sarcoid arthritis and 15 non-inflammatory joint diseases . Group differences were found for many baseline variables, but with considerable overlap between the groups . A set of four clinical and laboratory variables (elevated CRP, genitourinary symptoms, metatarsophalangeal joint involvement . HLA B27) could predict reactive arthritis with a sensitivity of 69.2% and a specificity of 93.5% . A wide range of clinical and laboratory examinations are required to determine the final diagnosis in oligoarthritis, but individual and sets of clinical and laboratory measures may give helpful clues for the correct diagnosis.

J Bacteriol, 1996 Apr, 178(7), 1895 - 902
Distribution of the rol gene encoding the regulator of lipopolysaccharide O-chain length in Escherichia coli and its influence on the expression of group I capsular K antigens; Dodgson C et al.; The rol (cld) gene encodes a protein involved in the expression of lipopolysaccharides in some members of the family Enterobacteriaceae . Rol interacts with one or more components of Rfc-dependent O-antigen biosynthetic complexes to regulate the chain length of lipopolysaccharide O antigens . The Rfc-Rol-dependent pathway for O-antigen synthesis is found in strains with heteropolysaccharide O antigens, and, consistent with this association, rol-homologous sequences were detected in chromosomal DNAs from 17 different serotypes with heteropolysaccharide O antigens . Homopolymer O antigens are synthesized by a pathway that does not involve either Rfc or Rol . It was therefore unexpected when a survey of Escherichia coli strains possessing mannose homopolymer O8 and O9 antigens showed that some strains contained rol . All 11 rol-positive strains coexpressed a group IB capsular K antigen with the O8 or O9 antigen . In contrast, 12 rol-negative strains all produced group IA K antigens in addition to the homopolymer O antigen . Previous research from this and other laboratories has shown that portions of the group I K antigens are attached to lipopolysaccharide lipid A-core, in a form that we have designated K(LPS) . By constructing a hybrid strain with a deep rough rfa defect, it was shown that the K40 (group IB) K(LPS) antigen exists primarily as long chains . However, a significant amount of K40 antigen was surface expressed in a lipid A-core-independent pathway . The typical chain length distribution of the K40 antigen was altered by introduction of multicopy rol, suggesting that the K40 group IB K antigen is equivalent to a Rol-dependent O antigen . The prototype K30 (group IA) K antigen is expressed as short oligosaccharides (primarily single repeat units) in K(LPS), as well as a high-molecular-weight lipid A-core-independent form . Introduction of multicopy rol into the K30 strain generated a novel modal pattern of K(LPS) with longer polysaccharide chains . Collectively, these results suggested that group IA K(LPS) is also synthesized by a Rol-dependent pathway and that the typically short oligosaccharide K(LPS) results from the absence of Rol activity in these strains.

Ned Tijdschr Geneeskd, 1996 Mar 23, 140(12), 654 - 8
{Problems in the use, cleaning and maintenance of nebulization equipment in the home situation}; Struycken VH et al.; OBJECTIVE . To determine whether jet nebulizers used at home for the treatment of children with asthma are used optimally . DESIGN . Descriptive . SETTING . Outpatient clinic for child pulmonary diseases of the Academic Hospital/Sophia Children's Hospital Rotterdam and outpatient clinic for child diseases of the Baronie Hospital Breda, the Netherlands . METHOD . Thirty-nine children aged 0-13 years and their parents were interviewed at home, and medication cup, saline and aerosol were cultured for bacterial analysis . The pressures of the compressor and nebulizer were measured with a manometer, and the particle size of the aerosol of 10 jet nebulizers was measured by laser technique . RESULTS . The suppliers of the nebulizer did not provide clear instructions on user-related aspects and technical maintenance of the jet nebulizer . Many patients used damaged and poorly functioning, contaminated jet nebulizers . Contamination by potentially pathogenic micro-organisms was present in 50% of the saline, medication cups and aerosols (Klebsiella, Enterobacter, Pseudomonas, Serratia, Escherichia coli) . The operating pressure of compressor and nebulizer was below the requirements in more than 50% of the jet nebulizers . In addition, we found that the aerodynamic mass median diameter increased considerably as the nebulizer became older . In 6/10 nebulizers the particle size was below 5 microns . CONCLUSION . A periodical checkup of user-related aspects and technical quality of jet nebulizers is necessary . The quality of the instruction to users about the procedure for cleaning and maintenance of the jet nebulizer should be improved.

Biochemistry, 1996 Mar 19, 35(11), 3604 - 13
Beta-secondary and solvent deuterium kinetic isotope effects on beta-lactamase catalysis; 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 depsipeptide substrate, m-{{(phenylacetyl)glycyl}-oxy}benzoic acid, and of a beta-lactam substrate, penicillanic acid, by three typical class A beta-lactamases and a class C beta-lactamase . The isotope effects on alkaline hydrolysis of these substrates have been used as a frame of reference . The effect of the transition state conformation of the substrates in determining the beta-secondary isotope effects has been explicitly considered . The inverse beta-secondary isotope effects on both V/K and V for the class A enzymes with both substrates indicate transition states where the carbonyl group of the scissile bond has become tetrahedral and therefore reflect typical acyl-transfer transition states . The solvent isotope effects indicate that enzyme deacylation (as reflected in V for the Staphylococcus aureus PC1 beta-lactamase) may be a classical general-base-catalyzed hydrolysis but that there is little proton motion in the enzyme acylation transition state (as revealed by V/K) for the TEM beta-lactamase and Bacillus cereus beta-lactamase I . These results provide kinetic support for the conjecture made on structural grounds that class A beta-lactamases employ an asymmetric double-displacement mechanism . The isotope effects on V/K for the class C beta-lactamase of Enterobacter cloacae P99 suggest an acyl-transfer transition state for the penicillin, although, as for the class A enzymes, without significant proton motion . On the other hand, the V/K transition state for depsipeptide does not seem to involve covalent chemistry . Suggestive of this conclusion are the measured beta-secondary isotope effect of 1,002 +/- 0.012 and the inverse solvent isotope effect . These results provide an example of a significant difference between the kinetics of turnover of a beta-lactam and a depsipeptide by a beta-lactamase . The V transition state for both substrates with the P99 beta-lactamase probably involves acyl-transfer (deacylation) where the conformation of the acyl-enzyme is closely restricted . The conformations of acyl-enzymes of the PC1 and P99 beta-lactamases correlate to the (different) dispositions of general base catalysts at their active sites.

Biochemistry, 1996 Mar 19, 35(11), 3595 - 603
Kinetics and mechanism of the hydrolysis of depsipeptides catalyzed by the beta-lactamase of Enterobacter cloacae P99; Xu Y et al.; The steady-state kinetics and mechanism of the hydrolysis and aminolysis of a series of acyclic depsipeptides, catalyzed by the class C beta-lactamase of Enterobacter cloacae P99, have been studied in order to more firmly establish the nature of the transition states involved . The class C beta-lactamase of Enterobacter cloacae P99 was employed . The depsipeptide substrates contained a constant acyl group, (phenylacetyl)glycyl, and chemically different leaving groups, m-carboxyphenoxide, m-carboxythiophenoxide, 3-carboxyl-4-nitrophenoxide, lactate, and thiolactate . Evaluation of the steady-state kinetic parameters and the effect of the alternative nucleophile methanol on these parameters and on the product distribution showed that deacylation was largely rate-determining to turnover of the aryl esters under conditions of substrate saturation, while acylation was rate-determining to the alkyl esters . The earlier conclusion {Govardhan & Pratt (1987) Biochemistry 26, 3385-3395} that acylation largely limited the turnover of the aryl esters was shown to be an artifact of phosphate buffer inhibition . The aminolysis of both the aryl the alkyl esters by D-phenylalanine was influenced by binding of the substrate at a second binding site on the acyl-enzyme intermediate . A study of inhibiton of the hydrolysis of (phenylacetyl)-glycyl-D-thiolactate by the aminolysis product (phenylacetyl)glycyl-D-phenylalanine indicated that the second binding site is also available for ligands to bind the free enzyme and to the noncovalent Michaelis complex with this substrate . It is likely that penicillin-recognizing enzymes in general, both beta-lactamases and DD-peptidases, possess an extended substrate-binding site into which a variety of small ligands may bind at any point along the reaction coordinate and, to a greater or lesser extent depending on circumstances, affect catalysis.

Vet Rec, 1996 Mar 9, 138(10), 223 - 6
Detection of antibodies to Salmonella enteritidis in sera and yolks from experimentally and naturally infected chickens; Desmidt M et al.; An indirect enzyme-linked immunosorbent assay (ELISA) based on the lipopolysaccharide (LPS) of Salmonella enteritidis phage type 4, was developed for the detection of antibodies to salmonella . Sera and yolks from chickens infected experimentally with S enteritidis showed strong positive reactions . Cross-reactions occurred with sera from chickens inoculated with S typhimurium or S gallinarum . Cross-reactions were weak with sera from chickens infected with five strains of other Enterobacteriaceae . The ELISA was tested with sera and yolks from commercial poultry flocks which were bacteriologically negative for salmonella or infected with salmonella serotypes belonging to serogroup D or to other serogroups . The serological reactions were strong in most flocks infected with S enteritidis and were weaker in flocks infected with S typhimurium . In some flocks infected with these serotypes no antibodies were detected . The correct setting of the cut-off value of the optical density in the ELISA makes it possible to discriminate between chickens which are infected with S enteritidis and chickens which are not infected with S enteritidis.

Southeast Asian J Trop Med Public Health, 1996 Mar, 27(1), 63 - 70
Pyruvate: ferredoxin oxidoreductase from Entamoeba histolytica recognized by a monoclonal antibody; Thammapalerd N et al.; A mouse monoclonal antibody, Eh208C2-2 MAb, raised against whole cell antigens of Entamoeba histolytica trophozoites of the pathogenic strain HM-1: IMSS and polyclonal antisera (PAb) against membrane antigens of E . histolytica trophozoites of strain HTH-56: MUTM were screened against a cDNA library of the pathogenic strain, SFL3 . The monoconal antibody detected many phage plaques expressing an E . histolytica protein . The DNA sequence encoding the protein was approximately 55% identical, over 1,100bp, to Trichomonas vaginalis pyruvate: ferredoxin oxidoreductase (PFOR) and pyruvate: flavodoxin oxidoreductase from Klebsiella pneumoniae, Anabaena variabilis and Enterobacter agglomerans . Two of seven clones detected by mouse polyclonal antisera also encoded this protein . Two others encoded Entamoeba Hsp70, another encoded Entamoeba alkyl-hydroperoxide reductase and the remaining two were unidentified sequences . Entamoeba PFOR is an abundant, antigenic protein which may be a useful target for the development of protective host immune responses against invasive amebiasis.

Jpn J Antibiot, 1996 Mar, 49(3), 279 - 88
{Antibacterial activities of combination uses of isepamicin and beta-lactams in vitro against clinically isolated strains . Part 2 . The results against enterobacteriaceae}; Deguchi K et al.; We investigated antibacterial activities of combination uses of isepamicin (ISP) and beta-lactams in vitro against Klebsiella pneumoniae and Enterobacter cloacae, and the following conclusions were obtained . 1 . ISP+cefazolin, ISP+cefotiam and ISP+flomoxef against K . pneumoniae and ISP+piperacillin, ISP+ceftazidime, ISP+aztreonam, ISP+imipenem and ISP+panipenem against E . cloacae showed strong combined effects . 2 . The minimum inhibitory concentrations (MICs) of these combinations were low due to the dependence of ISP concentrations . Strong antibacterial activities were observed at sub-MIC levels of ISP . These combined effects were stronger than those against Staphylococcus aureus described in the first report at sub-MIC levels of ISP . 1/4 MIC approximately 1/8 MIC of ISP showed enhanced activities of beta-lactams . Similarly strong combined effects were observed against both beta-lactam-sensitive and -resistant strains.

J Clin Microbiol, 1996 Mar, 34(3), 564 - 8
Molecular epidemiology of Klebsiella pneumoniae producing SHV-5 beta- lactamase: parallel outbreaks due to multiple plasmid transfer; Prodinger WM et al.; Over a period of 22 months, 32 patients treated in three independent intensive care units of the Innsbruck University Hospital were infected with extended-spectrum beta-lactamase-producing members of the family Enterobacteriaceae (30 Klebsiella pneumoniae isolates, 1 Klebsiella oxytoca isolate, and 1 Escherichia coli isolate) . As confirmed by sequencing of a bla gene PCR fragment, all isolates expressed the SHV-5-type beta-lactamase . Genomic fingerprinting of epidemic strains with XbaI and pulsed-field gel electrophoresis grouped 20 of 21 isolates from ward A into two consecutive clusters which included 1 of 3 ward B isolates . All six K . pneumoniae isolates from ward C formed a third cluster . Stool isolates of asymptomatic patients and environmental isolates belonged to these clusters as well . Additionally, 2,600 routine K . pneumoniae isolates from the surrounding provinces (population, 900,000) were screened for SHV-5 production . Only one of six nonepidemic isolates producing SHV-5 beta-lactamase was matched with the outbreak strains by genomic fingerprinting . Plasmid fingerprinting, however, revealed the epidemic spread of a predominant R-plasmid, with a size of approximately 80 kb, associated with 29 of the 30 K . pneumoniae isolates . This plasmid was also present in the single K . oxytoca and E . coli isolates from ward C and in three nonepidemic isolates producing SHV-5 . Our results underline that strain typing exclusively on the genomic level can be misleading in the epidemiological investigation of plasmid-encoded extended-spectrum beta-lactamases . Our evidence for multiple events of R-plasmid transfer between species of the family Enterobacteriaceae in this nosocomial outbreak stresses the need for plasmid typing, especially because SHV-5 beta-lactamase seems to be regionally spread predominantly via plasmid transfer.

Clin Infect Dis, 1996 Mar, 22(3), 430 - 6
Outbreak of multiply resistant enterobacteriaceae in an intensive care unit: epidemiology and risk factors for acquisition; Lucet JC et al.; A prospective study was initiated in an intensive care unit (ICU) where extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBLPE) were endemic . From July 1990 to July 1991, patients hospitalized for > or = 5 days were screened for ESBLPE acquisition by means of weekly rectal sampling and clinical cultures . Baseline characteristics and various ICU procedures in 62 cases of ESBLPE were compared with those for 205 patients without ESBLPE, with use of Cox's model . Risk for acquiring ESBLPE (Klebsiella pneumoniae in most cases) increased during the ICU stay, from 4.2% in the first week to 24% in the fourth week . Baseline characteristics were not different between the two groups . Urinary catheterization (P = .04) and arterial catheterization (P = .03) were independent risk factors for acquiring ESBLPE and probably reflected frequency of health care manipulations . The first site of ESBLPE acquisition was the digestive tract in 58 of the 62 patients; 28 infections developed in 22 patients, and these followed or occurred simultaneously with rectal colonization in 18 of those 22 . DNA macrorestriction analysis suggested that the same strain was responsible for most cases . In conclusion, ESBLPE acquisition depends on length of stay in the ICU and the use of invasive procedures . Colonization is a prerequisite for infection.

Clin Infect Dis, 1996 Mar, 22(3), 424 - 9
The epidemiology of chest and leg wound infections following cardiothoracic surgery; L'Ecuyer PB et al.; The occurrence of wound infections following cardiothoracic surgery has significant implications . However, the epidemiology of all chest and leg wound infections is infrequently described, and the effects on morbidity, mortality, and cost of care remain undefined . We identified 182 superficial and deep chest and leg infections in 163 patients following 1,554 coronary artery bypass graft (CABG), valve, and CABG/valve procedures over 30 months . The overall infection rate was 11.7%; infections of specific sites involved in the 1,554 procedures occurred at the following rates: 3.1%, superficial chest wounds; 2.3%, deep chest wounds; 4.6%, superficial leg wounds; and 2.2%, deep leg wounds . Chest infection rates were similar for all procedures . Multiple infections occurred in 9.8% of patients and were associated with female sex, diabetes, and prolonged surgery (P < .05) . Purulent drainage and fever were more common in chest infections; erythema and pain were more common in leg infections (P < .05) . Staphylococcus aureus (32.9%), coagulase-negative staphylococci (27.4%), and Enterobacteriaceae (26.0%) were identified most commonly . Enterobacteriaceae were more commonly isolated from leg wounds (P < .05) . Adverse outcomes included reexploration (20.9%), flap surgery (12.3%), and death (4.3%) . All adverse outcomes were more commonly associated with deep chest infections (P < .05), but superficial chest and leg infections also had a substantial impact on cardiothoracic surgery-related morbidity . Studies are needed to define site-specific risk factors so that the full potential of prevention and control measures can be realized.

Antimicrob Agents Chemother, 1996 Mar, 40(3), 616 - 20
Characterization of beta-lactamase gene blaPER-2, which encodes an extended-spectrum class A beta-lactamase; Bauernfeind A et al.; Plasmidic extended-spectrum beta-lactamases of Ambler class A are mostly inactive against ceftibuten . Salmonella typhimurium JMC isolated in Argentina harbors a bla gene located on a plasmid (pMVP-5) which confers transferable resistance to oxyiminocephalosporins, aztreonam, and ceftibuten . The beta-lactamase PER-2 (formerly ceftibutenase-1; CTI-1) is highly susceptible to inhibition by clavulanate and is located at a pI of 5.4 after isoelectric focusing . The blaPER-2 gene was cloned and sequenced . The nucleotide sequence of a 2.2-kb insert in vector pBluescript includes an open reading frame of 927 bp . Comparison of the deduced amino acid sequence of PER-2 with those of other beta-lactamases indicates that PER-2 is not closely related to TEM or SHV enzymes (25 to 26% homology) . PER-2 is most closely related to PER-1 (86.4% homology), an Ambler class A enzyme first detected in Pseudomonas aeruginosa . An enzyme with an amino acid sequence identical to that of PER-1, meanwhile, was found in various members of the family Enterobacteriaceae isolated from patients in Turkey . Our data indicate that PER-2 and PER-1 represent a new group of Ambler class A extended-spectrum beta-lactamases . PER-2 so far has been detected only in pathogens (S . typhimurium, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis) isolated from patients in South America, while the incidence of PER-1-producing strains so far has been restricted to Turkey, where it occurs both in members of the family Enterobacteriaceae and in P . aeruginosa.

Genetics, 1996 Mar, 142(3), 1037 - 43
Site-specific codon bias in bacteria; Smith JM et al.; Sequences of the gapA and ompA genes from 10 genera of enterobacteria have been analyzed . There is strong bias in codon usage, but different synonymous codons are preferred at different sites in the same gene . Site-specific preference for unfavored codons is not confined to the first 100 codons and is usually manifest between two codons utilizing the same tRNA . Statistical analyses, based on conclusions reached in an accompanying paper, show that the use of an unfavored codon at a given site in different genera is not due to common descent and must therefore be caused either by sequence-specific mutation or sequence-specific selection . Reasons are given for thinking that sequence-specific mutation cannot be responsible . We are unable to explain the preference between synonymous codons ending in C or T, but synonymous choice between A and G at third sites is largely explained by avoidance of AG-G (where the hyphen indicates the boundary between codons) . We also observed that the preferred codon for proline in Enterobacter cloacea has changed from CCG to CCA.

Genetics, 1996 Mar, 142(3), 1033 - 6
Synonymous nucleotide divergence: what is "saturation"?
Smith JM, Smith NH.
The nucleotide divergence at synonymous third sites between two lineages will increase with time since the latest common ancestor, up to some saturation level . The "null-hypothesis divergence" is defined as the percentage of difference predicted at synonymous third sites, allowing for amino acid composition and codon bias, but assuming that codon bias is the same at all sites occupied by a given amino acid, when equilibrium has been reached between forward and backward substitutions . For two highly expressed genes, gapA and ompA, in the enterobacteria, the estimated values of the null-hypothesis divergence are 39.3 and 38.15%, respectively, compared to estimated values of saturation divergence of 19.0 and 25.4% . A possible explanation for this discrepancy is that different codons for a given amino acid are favored at different sites in the same gene.

Mol Microbiol, 1996 Mar, 19(5), 949 - 63
Expression of Shigella sonnei lipopolysaccharide in Vibrio cholerae; Viret JF et al.; Making use of a newly designed mobilizable suicide vector, the genetic determinants encoding Shigella sonnei lipopolysaccharide (LPS) were stably integrated into the chromosome of the live attenuated Vibrio cholerae vaccine strain CVD103-HgR . Expression studies showed that the production of complete S . sonnei O-polysaccharide (O-PS)-bearing LPS was limited in bivalent recombinant strains that were also proficient in the synthesis of the host-encoded Inaba O-PS . Conversely, high amounts of LPS carrying S . sonnei O-PS are produced in monovalent Inaba-deficient derivatives, even in those strains which do not co-express the compatible R1 LPS core . Thus, the non-enterobacterial V . cholerae LPS core efficiently acts as a receptor for covalent binding of S . sonnei O-PS provided that competition with the host O-PS is avoided . Expression of the R1 core interferes with cell division in recombinant V . cholerae without affecting other physiological properties of vaccine strain CVD103-HgR . Both monovalent and bivalent strains stimulated high serum-antibody titres specific for their respective O-serotype(s) when administered to rabbits . The potential of V . cholerae as an expression carrier for heterologous O-serotypes is discussed.

J Biochem (Tokyo), 1996 Mar, 119(3), 468 - 74
Prolyl aminopeptidase is also present in Enterobacteriaceae: cloning and sequencing of the Hafnia alvei enzyme-gene and characterization of the expressed enzyme; Kitazono A et al.; The Hafnia alvei prolyl aminopeptidase gene (hpap) was cloned and sequenced, the expressed enzyme (HPAP) was purified to homogeneity and thoroughly characterized . An open reading frame of 1,281 bp was found to code for the enzyme, resulting in a protein of 427 amino acids with a molecular weight of 48,577 . HPAP resembles the Aeromonas sobria enzyme, having 45% identity and the same distinctive properties with respect to size and substrate specificities . Both enzyme show similar chromatographic behavior, and HPAP could be purified following the procedure previously described for the Aeromonas enzyme . HPAP was found to be resistant to diisopropylphosphofluoridate as are most of the prolyl aminopeptidases hitherto described . In spite of this similarity, no inhibition by 1 mM p-chloromercuribenzoate solution could be detected . Significant inhibition was, however, observed when the enzyme was incubated with 3,4-dichloroisocoumarin . This study confirms the presence of two types of prolyl aminopeptidases, of which the Hafnia and Aeromonas enzymes constitute one group and the Bacillus, Neisseria, and Lactobacillus enzymes the other, and describes the cloning of the first prolyl aminopeptidase gene from an Enterobacteriaceae.

Mol Biol Evol, 1996 Mar, 13(3), 451 - 61
Sequence heterogeneities among 16S ribosomal RNA sequences, and their effect on phylogenetic analyses at the species level; Cilia V et al.; We have analyzed what phylogenetic signal can be derived by small subunit rRNA comparison for bacteria of different but closely related genera (enterobacteria) and for different species or strains within a single genus (Escherichia or Salmonella), and finally how similar are the ribosomal operons within a single organism (Escherichia coli) . These sequences have been analyzed by neighbor-joining, maximum likelihood, and parsimony . The robustness of each topology was assessed by bootstrap . Sequences were obtained for the seven rrn operons of E . coli strain PK3 . These data demonstrated differences located in three highly variable domains . Their nature and localization suggest that since the divergence of E . coli and Salmonella typhimurium, most point mutations that occurred within each gene have been propagated among the gene family by conversions involving short domains, and that homogenization by conversions may not have affected the entire sequence of each gene . We show that the differences that exist between the different operons are ignored when sequences are obtained either after cloning of a single operon or directly from polymerase chain reaction (PCR) products . Direct sequencing of PCR products produces a mean sequence in which mutations present in the most variable domains become hidden . Cloning a single operon results in a sequence that differs from that of the other operons and of the mean sequence by several point mutations . For identification of unknown bacteria at the species level or below, a mean sequence or the sequence of a single nonidentified operon should therefore be avoided . Taking into account the seven operons and therefore mutations that accumulate in the most variable domains would perhaps increase tree resolution . However, if gene conversions that homogenize the rRNA multigene family are rare events, some nodes in phylogenetic trees will reflect these recombination events and these trees may therefore be gene trees rather than organismal trees.

Infection, 1996 Mar-Apr, 24(2), 144 - 6
Etiological agents and predisposing factors of intracranial abscesses in a Greek university hospital; Sofianou D et al.; The bacteriology for 21 patients with brain abscesses is presented and correlated with their predisposing conditions . Chronic otomastoiditis was the most common predisposing factor, and the overall most frequent infected sites were the frontal and temporal regions . Gram-negative non-sporeforming anaerobes of the genus Bacteroides and Fusobacterlum followed by aerobic streptococci were the predominant pathogens . Enterobacteria were only identified in postcraniotomy abscesses, while a substantial number of fastidious species was detected in suppurations related to congenital heart disease . Altogether, anaerobes alone were recovered in seven patients, aerobes alone in six, and mixed aerobes and anaerobes in four patients . These findings confirm the predominant role of anaerobes in the etiology of intracranial suppurations.

Arq Neuropsiquiatr, 1996 Mar, 54(1), 75 - 81
{Neonatal bacterial meningitis: prospective study of the long-term outcome of 55 children}; Jornada Krebs VL et al.; Fifty-five infants who presented bacterial neonatal meningitis were prospectively studied to analyze the frequency and the type of sequelae . All the infants were full term newborns . There were 38 boys and 17 girls; the age of disease onset varied from 3 to 28 days . The causative organism was represented mainly by enterobacteriae . The median time of follow-up was 5 years . The frequency of neurologic sequelae was 63.7%, represented mainly by neuropsychomotor development delay (58.2%), hydrocephaly (45.5%) and convulsions (34.5%) . Severe motor abnormalities ocurred in 23.6% of children (quadriplegia, diplegia, hemiparesia and ataxia) . Convulsions in the acute phase of the disease and the positive cerebrospinal fluid culture were highly associated to sequelae . The school performance, obtained in 25 children, showed presence of disabilities in 48% of cases, which were significantly associated to mental retardation.

Zh Mikrobiol Epidemiol Immunobiol, 1996 Mar-Apr, (2), 91 - 4
{Microbiological monitoring of suppurative-septic hospital infections in newborn infants and puerperae}; Musina LT et al.; The microbiological monitoring of obstetric institutions revealed essential changes in the microbiological structure of hospital purulent septic infections in newborns and parturient women during the period of 1987-1992 . An increase in the role of gram-negative microflora, mainly the representatives of the family Enterobacteriaceae, was registered . The specific proportion of gram-negative microorganisms in the etiology of hospital infections increased from 43.7% to 95.1% in newborn infants and from 33.3% to 61.3% in parturient women, which differently affected on the structure of the main nosological forms of these diseases.

Zh Mikrobiol Epidemiol Immunobiol, 1996 Mar-Apr, (2), 17 - 20
{The wound microflora of patients with gunshot injuries to the extremities during a mass hospitalization}; Men'shikov DD et al.; The dynamic study of the microflora of bullet wounds in 32 patients was carried out . In cases of mass hospitalization coccal microflora (staphylococci and streptococci) was mainly isolated from wounds, at the period of treatment hospital infections with enterobacteria, Pseudomonas and Enterococcus occurred . Before cleaning the wound a decrease in the contamination rate for all microbial species was observed . As the disease progressed an increase in the amount of antibiotic-resistant bacterial strains was registered . The results of sanitary microbiological investigations made in the wards where the wounded patients were treated correspond to the structure of the causative agents of purulent processes in patients.

Chemotherapy, 1996 Mar-Apr, 42(2), 90 - 9
Bactericidal activity, morphological alterations, and synergistic interactions of rufloxacin, a new fluoroquinolone, alone and in combination with its N-desmethylate D derivative (MF 922); Marchese A et al.; The in vitro activity of rufloxacin, alone and in combination with its metabolite (MF 922) against common respiratory and urinary tract pathogens and anaerobes was assessed . No synergistic interaction between rufloxacin and MF 922 was observed by the checkerboard technique against aerobic bacteria . When the time-kill system was employed, 24 synergistic interactions were noted out of 30 tests performed (80%), of which 14 (100%) were with Enterobacteriaceae isolates, 2 with Moraxella catarrhalis (50%), 4 with Haemophilus influenzae (100%), 2 with Staphylococcus aureus (50%) and 2 with Streptococcus pneumoniae and Streptococcus pyogenes (50%) . Synergism was found with all Bacteroides fragilis irrespectively of the method used . Rufloxacin alone or in combination with MF 922, at concentrations achieved in vivo, induced morphological alterations in all the pathogens analyzed with the exception of M . catarrhalis and H . influenzae . Towards S . pyogenes and S . pneumoniae, the same levels of rufloxacin and MF 922 were capable of inducing only bacteriostatic rather than bactericidal effect, followed by reversible morphological modifications . The presence of 50% human serum in the test media did not affect the results.

Chemotherapy, 1996 Mar-Apr, 42(2), 100 - 6
Comparative in vitro activity of cefodizime and other antibiotics against pathogens recently isolated in Italy; Nicoletti G et al.; In the present study we tested the susceptibility to cefodizime on 1,985 selected nosocomial pathogens isolated in five laboratories . Moreover, we evaluated the epidemiology of the resistance of the tested strains to cefodizime and to other antibiotics clinically available in Italy . The susceptibility to cefodizime was determined with both MIC (microdilution method) and the agar diffusion method (Kirby-Bauer) . The Kirby-Bauer method was used to compare the antibiotics . Cefodizime was equivalent in activity to ceftazidime and ceftriaxone and was more active than piperacillin and amoxicillin + clavulanic acid . The activity of gentamicin (where tested) was generally comparable to that of cefodizime; ciprofloxacin had lower percentages of resistance against some species of Enterobacteriaceae and staphylococci.

Enferm Infecc Microbiol Clin, 1996 Mar, 14(3), 171 - 6
{Clinical relevance of gram-negative bacteria having inducible chromosomic beta-lactamase at an intensive care unit}; Navarro F et al.; BACKGROUND: The aim of the study was to determine the frequency of third-generation cephalosporins and aztreonam resistance in gram-negative bacteria with inducible chromosomal beta-lactamase (beta Lac-ind) after beta-lactam therapy in the medical-surgical intensive care unit (ICU) at a university-affiliated hospital . PATIENTS AND METHODS: We studied 34 infections in 29 patients admitted to the ICU . All were infected by strains with beta Lac-ind and all were treated with beta-lactam antibiotics . Susceptibility was determined by disc-diffusion . The beta-lactamase activity of those strains showing constitutive beta-lactamase overproduction were characterized by isoelectrofocusing . When this derepression occurred during the therapy, the strains were compared by genomic macrorestriction (PGFE) . RESULTS: In 29 out of 34 infections the initial strains was susceptible . In 11 cases, the culture were not negativized in spite of their susceptible pattern . In 4 cases there was derepression during therapy . In 5 cases the initial strains were derepressed . The microorganisms isolated more frequently were Pseudomonas aeruginosa (22 cases) and Enterobacter cloacae (5 cases) . The beta-lactamase activity detected correspond well with a betaLac-ind . In those cases with derepression during therapy, the initial susceptible strain and the resistant strain were identical by PGFE.

Biochem J, 1996 Mar 1, 314 ( Pt 2), 457 - 61
Phosphonamidate analogues of dipeptides with carboxypeptidase A and beta-lactamase-inhibitory activity: elucidation of the mechanism of beta-lactamase inhibition by electrospray mass spectrometry; Payne DJ et al.; A series of phosphonamidate compounds with different P1' amino acid residues have been shown to be irreversible inactivators of the serine beta-lactamase from Enterobacter cloacae P99 . The efficiency of inhibition (based on k2/K values) of P99 by these derivatives, ordered in decreasing potency, is: beta-phenyl-beta-Ala > L-Phe > beta-Ala > Gly > D-Phe > D-Pro > D-thiazolidine . The D- and L-Phe compounds also inhibit carboxypeptidase A . The proline and thiazolidine derivatives were phosphonamidate methyl esters, whereas the others were salts of diacids . Electrospray mass spectrometry showed that equimolar mixtures of the P99 enzyme with each of the following derivatives, Gly, D-Phe, L-Phe, beta-Ala and beta-phenyl-beta-Ala, effected efficient adduct formation (70-95% of enzyme modified), illustrating the particularly active nature of some of these compounds . All the primary amino acid derivatives gave a similar mass increment, which suggests the displacement of the variable P1' part of the molecule . This observation provides evidence that the compounds phosphonylate the active-site serine, with the phosphonamidate bond as the scissile bond and the amino acid as the leaving group . The thiazolidine derivative (phosphonamidate methyl ester) also appeared to work by the same mechanism . The comparable proline derivatives caused lower than expected mass shifts of 227-229, and therefore it is proposed that with these compounds both the amino acid and the phosphonamidate ester methoxy group were displaced at the phosphorus atom during the inhibition process . Therefore, electrospray mass spectrometry has provided both a measure of potency and a rationale for the mechanism of inhibition of P99 by these compounds.

J Med Microbiol, 1996 Mar, 44(3), 211 - 4
Experimental endogenous septicaemia caused by Klebsiella pneumoniae and Escherichia coli in mice; Hirakata Y et al.; Multi-resistant Klebsiella pneumoniae have recently occurred in several nosocomial outbreaks of septicaemia . An animal model resembling the pathophysiology of these infections in man would be very useful . A new model of endogenous septicaemia caused by K . pneumoniae and Escherichia coli strains in mice has been established . The mortality rate of conventional ddY mice given cyclophosphamide (CY) or fluorouracil (5-FU), each 200 mg/kg intraperitoneally, every other day was 70 and 100%, respectively . Pseudomonas aeruginosa septicaemia was observed in all dead mice treated with CY, whereas Enterobacteriaceae, including K . pneumoniae, were isolated from 90% of mice given 5-FU . Specific-pathogen-free mice, decontaminated with ampicillin and ceftazidime, were given multi-resistant K . pneumoniae CF504, CF514 or E . coli CF604, or CF614 carrying CAZ-1/TEM-5 plasmid by oral inoculation . Subsequent dosing with 5-FU induced lethal septicaemia caused by the inoculated strains in most of these mice, whereas CY did not regularly induce septicaemia . This model with 5-FU is considered to resemble closely the situation observed in man and to be beneficial for investigating pathophysiology and therapeutic strategies.

Burns, 1996 Mar, 22(2), 158 - 61
Visceral injuries, wound infection and sepsis following electrical injuries; Haberal M et al.; Visceral injuries, wound infection and sepsis were investigated in 226 inpatients who sustained electrical burns over a period of 15 years . Four patients who sustained thoracic and abdominal organ injuries were noted in this series . The patients had injuries of the small intestine, stomach, colon and the lung . All the patients received operative treatment . Two of them died of sepsis . Injuries to the internal organs should always be considered following high-voltage injuries, and they should be managed as early as possible . The data concerning wound infection and sepsis following electrical injuries were evaluated in three consecutive 5-year periods . Over this period of 15 years, different antibiotic regimens were used for prophylaxis and treatment . Most patients in the current series had been contaminated or infected by various pathogens prior to admission . Long-lasting administration of prophylactic antibiotics in these patients showed no improvement in controlling the sepsis . After 1987, most of the microorganisms were eliminated following more effective antimicrobial therapy . The progressive decrease in infection frequency of species such as Pseudomonas aeruginosa, Proteus mirabilis and Enterobacter cloacae, appeared to be causally related to the changes in the general therapeutic protocol which included new antibiotics . The infections caused by E . coli and Staphylococcus aureus showed a rather steady state . A marked increase in frequency of negative wound cultures was also noted between the years 1989 and 1993 . A gradual decrease in mortality rates was observed from the first to the last 5-year period, whereas mortality rates due to sepsis showed a gradual but slower decline . Sepsis (142 patients comprising 62.8 per cent of the total mortality rate) was the most frequent complication resulting in death.

J Bacteriol, 1996 Mar, 178(6), 1623 - 30
Aeromonas salmonicida possesses two genes encoding homologs of the major outer membrane protein, OmpA; Costello GM et al.; Two homologs of the outer membrane protein OmpA were identified in Aeromonas salmonicida by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and amino-terminal sequence analyses . An A . salmonicida genomic DNA library was constructed by using lambda GEM-11 and recombinant phage carrying both genes ompAI and ompAII) selected by immunoscreening . A 5.0-kb BamHI fragment containing the two genes in tandem was subcloned in pBluescript and used for further subcloning and sequencing of the genes . The encoded proteins (Mr = 33,564 and 32,536 for mature OmpAI and OmpAII, respectively) had only 64% identity with each other and otherwise had the highest level of homology to OmpA proteins from the members of the family Enterobacteriaceae . Based on the Escherichia coli OmpA model, an eight-stranded amphipathic beta-barrel model for the membrane assembly of the N-terminal half of OmpAI and OmpAII was predicted . Most variation between the two proteins was localized to the predicted surface loops and periplasmic turns, while the transmembrane strands and C-terminals domains were highly conserved . Expression of ompAI and ompAII separately in E . coli indicated that both genes could be independently transcribed from their own promoters and that both gene products were assembled into the E . coli outer membrane . A survey of different Aeromonas spp . by PCR revealed that possession of two tandem ompA genes was widespread among this genus . This is the first report of any bacterial species possessing two genes for homologs of this major outer membrane protein.

J Toxicol Environ Health, 1996 Feb 23, 47(3), 299 - 309
Inactivation of glutaraldehyde by reaction with sodium bisulfite; Jordan SL et al.; The microbiocidal activity of glutaraldehyde was inactivated by reaction with sodium bisulfite via formation of a proposed glutaraldehyde-bisulfite complex . High-performance liquid chromatography (HPLC) analysis of 2% (0.2M) alkaline glutaraldehyde indicated complete loss of glutaraldehyde at a 2.2:1 molar ratio of sodium bisulfite to glutaraldehyde . Neither 1.7% (0.17 M) sodium bisulfite alone nor the glutaraldehyde-bisulfite complex was microbiocidal when tested against Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, and Polybac Polyseed BOD seed inoculum . Bacterial inhibition tests indicated that the glutaraldehyde-sodium bisulfite complex had no effect on the growth of sewage microorganisms at concentrations as high as 50-100 ppm (5 x 10(-4)-1 x 10(-3) M), with an IC50 of 230-440 ppm (2.3 x 10(-3)-4.4 x 10(-3) M), based on glutaraldehyde concentration . A 28-close bottle test showed a 5-d biodegradation of 48% and 51%, and a 15-d biodegradation of 57% and 63% for 3:1 and 2.2:1 bisulfite to glutaraldehyde molar ratios, respectively . Acute aquatic toxicity testing with Daphnia magna demonstrated an LC50 of 41-109 ppm (4.1 x 10(-4)-10.9 x 10(-4) M) and a no-observed-effect concentration (NOEC) of 16 ppm (1.6 x 10(-4) M) for the proposed glutaraldehyde-bisulfite complex (based on glutaraldehyde concentration), approximately 10-fold higher than found for glutaraldehyde alone, indicating that the proposed glutaraldehyde-bisulfite complex is less toxic to the environment than glutaraldehyde.

Biochemistry, 1996 Feb 20, 35(7), 2104 - 11
Modifying the specificity and activity of the Enterobacter cloacae P99 beta-lactamase by mutagenesis within an M13 phage vector; Siemers NO et al.; A library of Enterobacter cloacae P99 beta-lactamase mutants was produced to investigate the importance of residues 286-290 for substrate binding and catalysis and to characterize mutants with altered specificities and activities for various 3'-substituted cephalosporins . This region of the enzyme is a component of the active site that has not been implicated as participating in the catalytic mechanism but, based on molecular modeling, should contact the 3' substituents of cephalosporins . Random mutagenesis was carried out within an M13 phage vector by hybridization mutagenesis, and the phage library could be highly enriched for active beta-lactamase genes by incubation of infected bacteria with beta-lactam antibiotics . The mutants were characterized by Michaelis-Menten kinetic analyses with several cephalosporin substrates and spanned a 25-fold range of k(cat), 24-fold range of K(m), and 6-fold range of k(cat)/K(m) values . All five amino acid positions were found to be permissive to substitution, but the active mutant proteins carried substitutions that likely maintained the structure of the region . Serine 287 was the least permissive to change, requiring small, uncharged residues for retention of catalytic activity . The variation of Michaelis-Menten kinetic parameters observed in these enzymes was shown to be significant in the context of in vitro cytotoxicity assays with the cephalosporin-doxorubicin prodrug C-Dox and is suitable for experiments to probe the relationship between enzyme kinetics and efficacy in enzyme-prodrug approaches to targeted therapy.

J Immunol, 1996 Feb 15, 156(4), 1490 - 6
Mast cells process bacterial Ags through a phagocytic route for class I MHC presentation to T cells; Malaviya R et al.; The pivotal role of mast cells in allergic reactions and inflammatory processes is well established and recent studies have suggested that mast cells may also have a role in specific immune responses . Because mast cells have been shown to phagocytose and kill enterobacteria, we wished to determine whether they could also process bacterial Ags for presentation to T cells . Using a model system in which a well-characterized T cell epitope is expressed within bacteria as a fusion protein, we demonstrate in this paper that mast cells are indeed capable of processing bacterial Ags for presentation through class I MHC molecules to T cell hybridomas after phagocytic uptake of live bacteria . Processing occurs from a number of Gram-negative enterobacteria including Salmonella typhimurium and Escherichia coli . Parallel assays show that processing of the model Ag from enterobacteria by mast cells is similar in efficiency to processing by peritoneal macrophages . Consistent with earlier observations demonstrating a function of the bacterial fimbrial protein FimH in promoting bacterial binding to mast cells, the magnitude of the Ag processing response of E . coli is influenced by bacterial expression of FimH . Taken together, these observations extend the range of cell types capable of the phagocytic pathway of Ag processing and suggest that mast cells may have a previously unrecognized role in the induction of specific immune responses to bacteria.

Vet Microbiol, 1996 Feb, 48(3-4), 207 - 21
Characterisation of monoclonal antibodies specific to SEF 21 fimbriae of Salmonella enteritidis and their reactivity with other Salmonellae and Enterobacteria; Sojka MG et al.; A panel of monoclonal antibodies (mAbs) specific to type 1 (SEF 2) fimbriae of S . enteritidis was produced using crude and HPLC purified preparations of SEF 21 fimbriae . Sixteen mAbs were selected by indirect ELISA using both purified SEF 21 antigen and whole cells of S . enteritidis . Eight mAbs were confirmed by immunoprecipitation assay to react specifically with SEF 21 fimbriae . These mAbs were further characterised for their reactivity patterns by the "whole cell" ELISA and latex agglutination test with a number of strains of Salmonella and other enterobacteria . Not all SEF 21 mAbs reacted in both ELISA and latex agglutination tests with whole bacterial cells . mAb 611 was the only one suitable for use in both tests . Unexpectedly these mAbs reacted with the type 1 fimbriae of many of the tested strains of enterobacteria . mAb 721 reacted with most strains of Salmonella (89.1%) and enterobacteria (71.4%) tested . mAb 611 reacted with 61%-75% of strains of Salmonella and with 6.9%-17.6% of enterobacteria in ELISA and latex tests respectively . These mAbs will be useful reagents for further characterisation of type 1 fimbriae expressed by members of the family Enterobacteriaceae.

Microbiology, 1996 Feb, 142 ( Pt 2), 277 - 88
The gene cluster directing O-antigen biosynthesis in Yersinia enterocolitica serotype 0:8: identification of the genes for mannose and galactose biosynthesis and the gene for the O-antigen polymerase; Zhang L et al.; The rfb gene cluster of Yersinia enterocolitica serotype O:8 (YeO8) strain 8081-c was cloned by cosmid cloning . Restriction mapping, deletion analysis and transposon mutagenesis showed that about 19 kb of the cloned DNA is essential for the synthesis and expression of the YeO8 O-side-chain in Escherichia coli . Deletion analysis generated a derivative that expressed semi-rough LPS, a phenotype typical of an rfc mutant lacking the O-antigen polymerase . The deletions and transcomplementation experiments allowed localization of the rfc gene to the 3'-end of the rfb gene cluster . The deduced YeO8 Rfc did not share significant amino acid sequence similarity with any other protein, but its amino acid composition and hydrophobicity profile are similar to those of identified Rfc proteins . In addition, the codon usage of the rfc gene is similar to other rfc genes . Nucleotide sequence analysis identified three other genes upstream of rfc . Two of the gene products showed 60-70% identity to the RfbM and RfbK proteins that are biosynthetic enzymes for the GDPmannose pathway of enterobacteria . The third gene product was about 50-80% identical to the bacterial GalE protein, UDPglucose 4-epimerase, which catalyses the epimerization of UDPglucose to UDPgalactose . Since mannose and galactose are both present in the YeO8 O-antigen repeat unit, the above three genes are likely to belong to the rfb gene cluster . A gene similar to the gsk gene downstream of rfc, and genes similar to adk and hemH upstream of the rfb gene cluster, were recognized . Thus the rfb gene cluster of YeO8 is located between the adk-hemH and gsk loci, and the order is adk-hemH-rfb-rfc-gsk in the chromosome . Also in other Yersinia spp., the locus downstream of the hemH gene is occupied by gene clusters associated with LPS biosynthesis.

FEMS Microbiol Lett, 1996 Feb 1, 136(1), 91 - 7
Crucial domains are conserved in Enterobacteriaceae porins; Simonet V et al.; With the recent resolution of the crystal structures of several bacterial porins, it is worthwhile to define the generality of their organization throughout the Enterobacteriaceae . The distribution of specific epitopes was analysed among various Gram-negative bacterial porins using anti-peptide antibodies specific to exposed, transmembrane spanning, or pore-forming regions of Escherichia coli porins . Anti-peptide antibodies which recognized the exposed epitopes indicated a great variability among the bacterial porins analysed . Interestingly, an antigenic site located in the internal loop L3 constricting the pore diameter was present in the majority of the bacterial porins tested . Two epitopes located in domains involved in subunit interaction were also highly conserved . The presence of these common peptides suggested a conservation of specific regions involved in the functional organization of the enterobacterial porins.

Poult Sci, 1996 Feb, 75(2), 191 - 6
Effect of hatching cabinet sanitation treatments on Salmonella cross-contamination and hatchability of broiler eggs; Bailey JS et al.; Four trials were conducted to evaluate the efficacy of hatcher air sanitation utilizing ultraviolet light (UV), ozone, or hydrogen peroxide on bacterial populations, the spread of Salmonella, and hatchability of broiler eggs . The UV light (254 nm, 146 mu W/s) and ozone (0.2 or 0.4 ppm) treatments were continuously applied through the last 3 d of hatch, the hydrogen peroxide treatment (2.5%) was administered 1 or 2 min of each 10 min at rates of 500 or 100 mL/h . Hatchability was not significantly reduced by sanitizing treatments when compared with the untreated control (94 vs 95.6%) . As compared to controls, all sanitizing treatments reduced 75 to 99% of the total bacteria, Enterobacteriaceae, and Salmonella in the hatching cabinet air samples . The use of hydrogen peroxide resulted in greater reduction of bacteria than ozone or UV light . Only hydrogen peroxide significantly reduced Salmonella levels on eggshell fragments . Significant reductions in the number of Salmonella-positive chicks occurred using the ozone and hydrogen peroxide treatments . Hydrogen peroxide significantly reduced the magnitude of Salmonella colonization in chicken ceca . These trials demonstrated that the spread of bacteria can be effectively reduced in the hatching cabinet by air sanitization using UV light, ozone, and hydrogen peroxide . The potential to reduce bacterial cross contamination in the hatcher is achievable without depressing hatchability.

Pediatr Infect Dis J, 1996 Feb, 15(2), 117 - 22
A prospective study of Gram-negative bacteremia in children; Levy I et al.; BACKGROUND: Hospital- and community-acquired Gram-negative bacteremia is a significant cause of mortality and morbidity in pediatric medical centers . Gram-negative organisms are isolated in > 50% of pediatric patients with bacteremia . OBJECTIVES: To analyze clinical and epidemiologic variables associated with Gram-negative bacteremia in a tertiary children's medical center . METHODS: A 6-year prospective study of children with Gram-negative bacteremia in a tertiary care children's medical center in Israel . RESULTS: Three hundred seventy-four episodes of Gram-negative bacteremia were studied during 6 years . The predominant isolates were Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which accounted for 109, 81 and 79 episodes (26, 20 and 19%), respectively . Of all episodes 43% occurred in neonates and infants younger than 2 years and 47% were hospital-acquired . Underlying conditions mainly acute leukemia and lymphoma, were present in 55% of the patients . Urinary tract infection followed by lower respiratory tract infection were the most common identified sources of bacteremia . Central intravenous catheters were associated with 53% of the episodes . The crude mortality was 11.4% . Increased mortality was significantly associated with acute leukemia, neutropenia, hospital-acquired infections and previous corticosteroid therapy (P = 0.03, 0.003, 0.006 and 0.01, respectively) . Increased antibiotic resistance of hospital-acquired vs community-acquired isolates was noted; 44 to 77% resistance of nosocomial Klebsiella and Enterobacter sp . to second and third generation cephalosporins and 18% were resistant to amikacin . CONCLUSIONS: Klebsiella pneumoniae is currently the most common organism causing Gram-negative bacteremia in children . Because of the relatively high resistance of Gram-negative organisms to second and third generation cephalosporins, we suggest that empiric antibiotic therapy for Gram-negative bacteremia include a combination of an aminoglycoside and an anti-Pseudomonas beta-lactam.

Mol Microbiol, 1996 Feb, 19(4), 659 - 66
The initiation mess?
Herrick J, Kohiyama M, Atlung T, Hansen FG.
This review concerns the mechanisms which control initiation of chromosome replication in enterobacteria with respect to cell growth . Initiation control is commonly separated into positive and negative regulatory mechanisms . Four main points are advanced concerning these different aspects of initiation control . (i) The average concentration of the initiator protein DnaA is proportional to the origin concentration, i.e . the origin per cell mass ratio and, thus, inversely proportional to the very often used term of the 'initiation mass' . (ii) The time of initiation of chromosome replication in the cell cycle is set by DnaA protein accumulating to a threshold level, which in concert with a number of other factors allows for a co-operative formation of the initiation complex . (iii) The time of initiation is not determined by the interaction with these other factors or by the transient interaction between newly replicated origins (oriC) and the cell surface . (iv) The aberrant initiation phenotype observed in various mutants, including dnaA (ts) mutants, might be due to a defective preinitiation DnaA-oriC interaction or it might be due to a defect in the protection of newly initiated origins from reinitiation . Many of these points are discussed and evaluated in view of recent developments concerning the regulation of chromosome replication in Escherichia coli.

J Mass Spectrom, 1996 Feb, 31(2), 138 - 49
Acid and base hydrolysis of lipid A from Enterobacter agglomerans as monitored by electrospray ionization mass spectrometry: pertinence to detoxification mechanisms; Wang Y et al.; Lipopolysaccharides (LPS), which are endotoxins found in the cell wall of Gram-negative bacteria, are common components of organic dusts that cause or contribute to symptoms associated with organic dust diseases . The lipid A subgroup within LPS is believed to be responsible for the toxicity . Acid and base treatments, which can be effective detoxification methods, were performed on lipid A from Enterobacter agglomerans (EA), a bacterium commonly found in field cotton . Negative-ion electrospray ionization mass spectrometry was employed to characterize the post-treatment structural changes to lipid A . Acid treatment (1% acetic acid, 100 degrees C) hydrolyzed the ester side-chains of lipid A . It was found that the ester-linked palmitoyl group was the most labile to acid hydrolysis . Hydrolysis of the palmitoyl moiety conformed to pseudo-first-order chemical reaction kinetics with a rate constant for decomposition of heptacyl-lipid A from Enterobacter agglomerans of approximately 3.3 x 10(-3) min-1 . An order of lability of lipid A acyl side-chains to acid hydrolysis was also deduced: R4' (palmitoyl) > R1' (myristoyl or hydroxymyristoyl) > R3 (hydroxymyristoyl at position 3) > R1 (oxymyristoyl group at position 3') > R2' (lauroyl) . Base treatment (0.05 M NaOH in 95% EtOH, 65 degrees C) was shown to be more effective at cleaving ester-linked side-chains . In addition, mass spectral evidence suggests that opening of the pyranose rings of the disaccharide backbone of lipid A and/or removal of the phosphoryl groups may be occurring during base treatment . This study sheds light on mechanistic aspects of treatment procedures leading to the detoxification of endotoxins.

J Clin Microbiol, 1996 Feb, 34(2), 463 - 5
Enterobacter cloacae producing a Shiga-like toxin II-related cytotoxin associated with a case of hemolytic-uremic syndrome; Paton AW et al.; Two Shiga-like toxin-producing organisms were isolated from the feces of an infant with hemolytic-uremic syndrome by PCR followed by colony blot hybridization . One strain was identified as Escherichia coli OR:H9, while the other was identified as Enterobacter cloacae . Both isolates were highly cytotoxic for Vero cells, and Southern hybridization analysis of chromosomal DNA indicated that both contained a single slt-II-related gene and that these genes were located on similarly sized restriction fragments . Nucleotide sequence analysis indicated that the toxin encoded by the E . cloacae slt-II-related gene was very similar to Shiga-like toxin II variants from E . coli, differing from the most closely related toxin by 3 residues in the A subunit.

Pathol Biol (Paris), 1996 Feb, 44(2), 138 - 40
{Practical use of cefepime in an University hospital . Retrospective study of 35 cases}; Gerard A et al.; The authors report a retrospective study of 35 patients treated with cefepime (Axepim) . This patients were either hospitalized in a medical or in a surgical ICU or were febrile neutropenic patients . The non neutropenic group was put on cefepime for nosocomial pneumonia or miscellaneous sepsis . When recovered, Enterobacteriaceae were the most frequent pathogens . Clinical cure rate for the patients treated with cefepime was 83% . Cefepime is a safe and effective empirical treatment for serious infections and nosocomial infections in particular.

Pathol Biol (Paris), 1996 Feb, 44(2), 99 - 105
{Specificities of antibacterial activity of zwitterionic 7-methoxyimino cephems (cephalosporins of fourth generation}; Pechere JC; Zwitterionic 7-methoxyimino cephalosporins possess a variable substitution at C3 which contains a quaternary nitrogen . These cephalosporins display low affinities for class I beta-lactamase and rapid penetration through the outer membrane of Gram negative bacilli . Hence, they remain active against some, but not all, ceftazidime-resistant Enterobacteriaceae . Antipseudomonas activities are generally similar to that of ceftazidime except that cefelidin is more active . The new zwitterionic compounds express greater antistaphylococcal potency than does ceftazidime . On the basis of structural and antibacterial characteristics the expression "forth generation" is acceptable to describe the wzitterionic 7-methoxyimino cephalosporins.

Can J Microbiol, 1996 Feb, 42(2), 201 - 6
Restriction analysis of actinomycetes chromosomal DNA; Novella IS et al.; Actinomycetes DNAs were digested with restriction enzymes to study the presence of methylated bases . Analysis showed that the enterobacterial Dam and Dcm systems are absent . Methylation at the internal cytosine in CCGG sequences, typical of eukaryotes, was also absent . We also tested 18 restriction endonucleases recognizing six base pair sequences (all of which were inhibited by methylation) . Results showed a higher number of restriction sites for enzymes recognizing CG-rich sequences (CG endonucleases) than for enzymes recognizing AT-rich sequences (AT endonucleases) . Restriction patterns with CG endonucleases were quite uniform, with the remarkable exception of XhoI, which yielded a small number of DNA bands . The study performed with AT endonucleases allowed differentiation of three groups of enzymes based on different degrees of chromosomal sensitivity . One group (BclI and BglII) produced restriction patterns with more abundant restriction sites than expected, a second group (ClaI, EcoRI, and EcoRV) yielded the predicted number of DNA fragments, and the third group (HpaI, HindIII, XbaI, and DraI) produced an unexpectedly low number of fragments . Some individual cases of resistance to particular enzymes could be explained by the presence of restriction-modification systems with the same specificity.

Can J Microbiol, 1996 Feb, 42(2), 196 - 201
Isolation and modulation of growth of a colonization-impaired strain of Enterobacter cloacae in cucumber spermosphere; Roberts DP et al.; Enterobacter cloacae A-46 was isolated for use in an environmental containment strategy for genetically modified derivative strains with enhanced biocontrol activity . The population of E . cloacae A-46, a transposon mutant of the plant-beneficial bacterium E . cloacae 501R3, increased 10-fold (significant increase at P < or = 0.05) in cucumber spermosphere when applied to cucumber seeds along with casamino acids . In contrast, strain A-46 was incapable of proliferation in cucumber spermosphere in the absence of casamino acids . Populations of strain A-46 also failed to increase in corn, cowpea, sunflower, and wheat spermospheres in the absence of casamino acids, while populations of strain 501R3 increased 3162-, 512-, 1698-, and 93-fold, respectively . In addition, the persistence of strain A-46 in corn, cucumber, and sunflower rhizospheres and in natural soil was greatly reduced compared with the parental strain 501R3.

J Chemother, 1996 Feb, 8 Suppl 2, 57 - 62
In vitro activity of fourth generation cephalosporins against enterobacteriaceae producing extended-spectrum beta-lactamases; Sanders CC; The in vitro activity of fourth generation cephalosporins against Enterobacteriaceae that produce extended-spectrum beta-lactamases (ESBLs) has not been extensively studied . From an examination of the data available in the published literature and from studies performed in the author's laboratory, several trends are apparent . Introduction of any ESBL into Escherichia coli significantly reduces activity . The precise impact of an ESBL on activity varies greatly with the specific ESBL present . Derivatives of SHV-1 tend to decrease activity more than derivatives of TEM-1 or TEM-2 although there is great variation within both of the major types of ESBLs . Activity of fourth generation cephalosporins against clinical isolates of ESBL-producing Enterobacteriaceae is significantly greater than that of ceftazidime . However, cefotaxime shows activity similar to that of fourth generation cephalosporins against certain strains . The value of fourth generation cephalosporins in treating infections due to ESBL-producing Enterobacteriaceae is currently unknown as there are no clinical data available that address this issue.

Jpn J Antibiot, 1996 Feb, 49(2), 175 - 93
{Antimicrobial activities of meropenem against clinically isolated strains}; Deguchi K et al.; In order to evaluate antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates in 1993 . The results were as follows; 1 . Antimicrobial activities of MEPM against Gram-positive bacteria were stronger than those of cephems (CEPs), were approximately equal to those of panipenem (PAPM), and were weaker than those of imipenem (IPM) . 2 . Carbapenems showed strong antimicrobial activities against Enterobacteriaccae, glucose non-fermentative Gram-negative rods and Bacteroides fragilis group that were multiple drug resistant including the third generation CEPs . Antimicrobial activities of MEPM against these organisms were stronger than those of IPM and PAPM . 3 . MIC-ranges of MEPM against Enterobacteriaceae and Haemophilus influenzae were lower than those of IPM and PAPM . We observed that MEPM had better permeability into the cells of H . influenzae, higher affinities to 3 to 5 different penicillin-binding protein and high stability against beta-lactamase than those of IPM and PAPM.

J Antimicrob Chemother, 1996 Feb, 37(2), 285 - 93
Comparative activity of piperacillin/tazobactam against 5625 isolates from hospitalised patients . Multicentre Study Group; Verbist L et al.; The comparative activities of piperacillin/tazobactam and other antibiotics against 5625 Gram-negative and Gram-positive bacteria freshly isolated from hospitalized patients was examined . The percentage of Enterobacteriaceae susceptible to piperacillin/tazobactam, ceftazidime, imipenem and ciprofloxacin was very similar and varied from 81% to 84% in the Enterobacteriaceae with inducible type 1 beta-lactamases and from 93 to 97% in the non-inducible organisms . Piperacillin/tazobactam was similar in activity to ceftazidime against Pseudomonas aeruginosa and more active than imipenem or ciprofloxacin . Piperacillin/tazobactam is more active than ceftazidime against Gram-positive bacteria (staphylococci, enterococci) and seems to be a promising antibiotic for nosocomial infections.

J Antimicrob Chemother, 1996 Feb, 37(2), 233 - 42
Quantitative comparison in vitro of mutational antibiotic resistance of Enterobacter spp . using a spiral plater; Yu CM et al.; The presence of spontaneous mutational antibiotic resistance among 18 bacteremic isolates of Enterobacter spp . to cefotaxime, ceftazidime, gentamicin, amikacin, ciprofloxacin, and trimethoprim-sulfamethoxazole was determined quantitatively in vitro using a spiral plater . Each drug was delivered using the device and the agar plates were inoculated in radial streaks . The degree of resistance was estimated by dividing the antimicrobial concentration required to inhibit 90% of the colonies growing in the area beyond the MIC by the MIC itself . The degree of resistance to third-generation cephalosporins and aztreonam was statistically significantly greater than that to co-trimoxazole, imipenem, and ciprofloxacin (P < 0.01); the latter three antibiotics showed virtually no mutational resistance . An intermediate level of resistance was induced by aminoglycosides, and mutational resistance to piperacillin varied between this and the higher levels observed for the cephalosporins . By providing a simple and efficient means of detecting spontaneous mutational resistance, the spiral plater may prove useful in identifying those antimicrobial agents which induce few or no mutants and therefore may be more likely to be successful in treating infections due to Enterobacter spp.

J Med Microbiol, 1996 Feb, 44(2), 89 - 98
Investigation of outbreaks of Enterobacter aerogenes colonisation and infection in intensive care units by random amplification of polymorphic DNA; Davin-Regli A et al.; During a 4-month period, 41 isolates of Enterobactor aerogenes were cultured from different specimens from a 14-bed intensive care unit (ICU1) . These were obtained from 12 patients out of a total of 187 patients admitted to the ICU . Sixteen E . aerogenes isolates were cultured from another ICU (ICU2) 6 months later . Six non-outbreaks associated strains were included as controls and all the isolates were compared by random amplification of polymorphic DNA (RAPD), with three different 10-mer oligonucleotide primers . RAPD fingerprinting with primer AP12h was as discriminatory as the combined results from all three primers and defined 22 different patterns for the 41 isolates from the ICU1 . In nine instances, isolates with indistinguishable RAPD patterns were detected in two-to-five patients over a 3-15-day period, suggesting patient-to-patient transmission . During their stay in ICU1, patients harboured one-to-12 distinguishable isolates . Isolates from ICU2 were indistinguishable by RAPD analysis with the three different primers . These findings suggest that the cluster of colonisations and infections in ICU1 was a 'false outbreak', consisting of successive patient-to-patient transmission of different E . aerogenes strains . In contrast, the outbreak on ICU2 probably involved the extensive spread of a single strain.

Am J Trop Med Hyg, 1996 Feb, 54(2), 219 - 23
The midgut bacterial flora of wild Aedes triseriatus, Culex pipiens, and Psorophora columbiae mosquitoes; Demaio J et al.; The midgut bacterial flora of wild-caught Aedes triseriatus, Culex pipiens, and Psorophora columbiae mosquitoes was investigated . Dissected midgut contents were examined using quantitative aerobic bacterial cultures . Individual colonies (n = 134) were subcultured and identified to species . Midgut bacterial counts changed dramatically during mosquito development . A 280-1,100-fold decrease in the bacterial population occurred between the larval stage and pupal emergence, whereas a subsequent 70-16,000-fold increase occurred after blood-feeding . Bacterial identifications revealed a complex flora with up to nine genera identified during any stage of development . Species most frequently isolated were Serratia marcescens, Klebsiella ozonae, Pseudomonas aeruginosa, and Enterobacter agglomerans . The presence of genetically well-characterized bacteria in the midgut flora of mosquitoes may provide a means of expressing novel genetic products in vector species.

Am J Trop Med Hyg, 1996 Feb, 54(2), 214 - 8
Bacterial population dynamics in three anopheline species: the impact on Plasmodium sporogonic development; Pumpuni CB et al.; The functional role of bacteria in the midgut of adult mosquitoes is unknown . In this study, we examined the population dynamics of midgut bacteria of laboratory reared Anopheles stephensi, An . gambiae, and An . albimanus . Mosquito midguts were dissected under sterile conditions and examined for the presence of bacteria using standard microbiologic techniques . Ninety percent and 73% (n = 30) of newly emerged An . gambiae and An . stephensi, respectively, harbored bacteria . In contrast, only 17% (n = 23) of An . albimanus harbored any bacteria . The bacterial population increased 11-40-fold in the presence of a blood meal, but then decreased to pre-blood meal levels in 3-5 days . Pseudomonas cepacia, Enterobacter agglomerans, and Flavobacterium spp . were found in all three anopheline species . Midgut bacteria were acquired both transtadially and through the sugar meal . Transtadial transmission was demonstrated by successfully passaging Escherichia coli HS5 from the larval to the adult stage . However, midgut bacteria were acquired more efficiently through the sugar meal than through transtadial passage . An increase in midgut bacterial counts after mosquitoes were exposed to a bacteria/sugar suspension significantly reduced oocyst infection rates and densities in Plasmodium falciparum-infected mosquito cohorts . Since bacteria occur naturally in wild mosquitoes, it may be possible to modify anopheline vector competence using introduced or indigenous bacteria.

Pediatr Nephrol, 1996 Feb, 10(1), 55 - 7
Bacteremia in a pediatric hemodialysis unit secondary to Enterococcus fecalis; Hymes LC et al.; Bacteremia is often a serious and recurring problem in children with hemodialysis catheters . We report an outbreak of Enterococcus bacteremia in a pediatric hemodialysis unit occurring from June 1992 to June 1993 . During this period, 18 episodes of bacteremia occurred in eight children; 11 infections were polymicrobial . Enterococcus fecalis was associated with 13 infections in five patients (8 polymicrobial) . Other pathogens included Enterobacter cloacae (5 infections), Staphylococcus (3), Staphylococcus epidermidis (2), and Klebsiella pneumoniae (2) . All Enterococcus infections occurred in patients with dual-lumen subclavian venous catheters . Skin and catheter sites were culture negative, except in one patient . Rectal swabs were positive for Enterococcus in five patients . Enterococcus was not isolated from any source within the unit . Serotypes of all Enterococcus isolates were different, except for 2 isolates in the same patient . Starting in June 1993, catheters were flushed after dialysis with vancomycin or ampicillin . Since initiating this procedure, further episodes of Enterococcus bacteremia have not occurred . A questionnaire sent to other pediatric hemodialysis units failed to identify Enterococcus among 26 cases of bacteremia . In conclusion: (1) Enterococcus is an unusual pathogen for hemodialysis-related bacteremia in children; (2) patients with dialysis catheters were predisposed to this infection; (3) a common source for Enterococcus could not be identified by either culture or by serotyping; (4) flushing catheters with antibiotics after dialysis was effective prevention.

J Bacteriol, 1996 Feb, 178(3), 823 - 30
A Bacteroides thetaiotaomicron outer membrane protein that is essential for utilization of maltooligosaccharides and starch; Reeves AR et al.; Previous studies suggested that the first step in utilization of starch by Bacteroides thetaiotaomicron was binding of the polysaccharide to the cell surface, followed by translocation of the polysaccharide across the outer membrane into the periplasm . In this study, we report the molecular characterization of a gene that encodes an outer membrane protein that is essential for utilization of both maltooligosaccharides and starch . The gene, susC, encoded a protein of 115.3 kDa . Antibodies were raised against SusC, and the outer membrane location of SusC could be confirmed by Western blot (immunoblot) analysis . SusC had a possible signal sequence of between 20 and 39 amino acids, depending on which N-terminal methionine initiates the start of the protein . It also had some features typical of well-characterized outer membrane proteins from members of the family Enterobacteriaceae, such as a terminal phenylalanine residue and a region in the amino portion of the protein thought to be involved in stabilizing the protein in the outer membrane . The amino acid sequence, together with results of gene disruption experiments, suggested that SusC was not an amylolytic enzyme . Transcriptional fusion experiments, using beta-glucuronidase as a reporter group, showed that expression of susC was maltose regulated at the transcriptional level . This is the first molecular characterization of a B . thetaiotaomicron outer membrane protein involved in maltooligosaccharide and starch utilization.

Lakartidningen, 1996 Jan 17, 93(3), 148 - 51, 154
{Increased antibiotic resistance of intestinal bacteria}; Hanberger H et al.; A survey of bacterial resistance rates in four intensive care units (ICU) at a Swedish university hospital showed an increase of ampicillin resistant enterococci from 3.2 percent 1993 to 17.7 percent 1994 . This increase of ampicillin-resistant enterococci was due to an increase of Enterococcus faecium with chromosomal ampicillin resistance . The survey also showed a relative high level of cefalosporine resistance, at the ICUs, among Enterobacter spp and to some extent among Escherichia coli and Klebsiella spp . A simultaneously performed survey of all blood isolates from the four hospitals in the county revealed the same development of resistance but the resistance rates were lower compared with the ICUs . To reduce the spread of resistant bacterial isolates there is a need for decreased and optimized antibiotic consumption as well as isolation of patients infected with resistant isolates.

Ned Tijdschr Geneeskd, 1996 Jan 6, 140(1), 31 - 4
{Systemic fat necrosis and septic arthritis in acute pancreatitis}; Reijnierse JE et al.; Systemic fatty necrosis secondary to acute pancreatitis was diagnosed in a 47-year-old man with high fever and painful nodules on the arms and the upper legs . This was complicated by fatal septic shock, septic arthritis and extensive soft tissue infections with Enterobacter cloacae, which was unsuccessfully treated with several antibiotic regimens, and from which the patient died.

Med Dosw Mikrobiol, 1996, 48(3-4), 169 - 75
{Microbiological evaluation of ciprofloxacin efficacy for treatment of urinary tract infections}; Kalisz J et al.; An attempt has been undertaken to evaluate the aetiology of urinary tract infections in a large group of patients and to determine the resistance to ciprofloxacin during therapy, and the efficacy of the drug in treating of urinary tract infections . 52 patients with urinary tract infections were treated with ciprofloxacin . Ciprobay by BAYER was used in coated 500 mg tablets twice a day and intravenous solutions in 200 mg dosages every 12 hours for 10-14 days depending on the clinical condition . Microbiological tests were made according to general methods . Sensitivity evaluation to ciprofloxacin was done using E-tests by AB Biodisk and dilution tests . The most common a etiology of urinary tract infections were Gram-negative Enterobacteriaceae rods, mainly E . coli . Ciprofloxacin gave the best results against Enterobacteriaceae rods (100% eradications) . In other infections, effective therapy was possible after determining of the sensitivity in vitro . S . haemolyticus bacteria tended significantly towards resistance to ciprofloxacin during therapy.

Immunobiology, 1996-97, 196(5), 550 - 66
An unique CD4+CD8+ intestinal intraepithelial lymphocyte specific for DnaK (Escherichia coli HSP70) may be selected by intestinal microflora of rats; Kimura Y et al.; We have previously shown an age-associated increase in unique CD4+CD8+ intestinal intraepithelial lymphocytes (i-IEL) in rats . To elucidate the potential causes of the increase in CD4+CD8+ i-IEL with age, we analyzed the specificity of the CD4+CD8+ i-IEL and influence of intestinal microflora on the increase in this subset in aged rats . The purified CD4+CD8+ i-IEL proliferated in response to DnaK {Escherichia coli (E . coli) HSP70} in the presence of mitomycin-c (MMC)-treated syngeneic spleen cells . The proportion of CD4+CD8+ T cells in whole i-IEL were significantly increased in aged rats fed commercial (CL-2) diet but not in those fed home-made (purified) diet under conventional condition . No CD4+CD8+ i-IEL were detected in aged rats under germfree condition, irrespective of diet feeding . A larger number of Enterobacteriaceae, especially E . coli, were detected in the intestinal contents and feces from aged rats with CD4+CD8+ i-IEL compared with those from aged rats fed without CD4+CD8+ i-IEL . The unique CD4+CD8+ i-IEL population specific for E . coli HSP may be associated with long term exposure to intestinal E . coli in aged rats.

Rev Laryngol Otol Rhinol (Bord), 1996, 117(3), 179 - 82
{Bacteriology of the nose and sinuses}; Stoll D et al.; The authors, on the basis of 140 cases, analyze the bacterial flora of essentially chronic rhino-sinusitis observed in hospital consultations at the Pellegrin Hospital, the referral centre of the Aquitaine region . Samples taken in the operating theatre from 100 cases, by aspiration and mucosal biopsy, were studied in aerobic and anaerobic media . The results marked by the scarcity of sterile samples and of anaerobic germs, evidence the predominance of an aerobic flora, with in particular Haemophilus influenzae, Staphylococcus aureus and beta-hemolytic Streptococci . No significant difference was recorded between the bacteriology of acute sinusitis as against chronic sinusitis . The flora of sinusitis appear to depend more on the age factor than on the pathogenic type . Branhamella catharralis is present only in patients under 30 . The enterobacteria appear in the adult 30-50 year-old age group and, as from the age of 50, are combined by Pseudomonas aeruginosa, which account for 18% of the strains . These two types of germs then appear to be predominant over the Staphylococci and the Haemophilus.

Acta Otolaryngol Suppl, 1996, 523, 130 - 2
Comparative bacteriology of the surface of normal and pathological palatine tonsils in children; Endo LH et al.; There are only few studies on the normal bacteriology of tonsils . The purpose of this study was to acquire knowledge about the normal microflora: patients without recurrent tonsillitis (RT) and without tonsil hypertrophy (TH) and to compare these results with the pathological microflora: patients who have recurrent tonsillitis and/or tonsillar hypertrophy . We did 132 cultures of tonsil surface obtained from normal children and 96 cultures from pathological surfaces during the summer and in the winter . Comparing normal and pathological groups, we found Neisseria spp and Enterobacteria spp more frequently in the normal group . There are differences in the surface microflora of tonsils from normal persons and from individuals with tonsillitis.

Verh Dtsch Ges Pathol, 1996, 80, 267 - 71
{Primary biliary cirrhosis--cellular mechanisms and role of enterobacterial antigens}; Lobeck H et al.; The nature of primary biliary cirrhosis (PBC) is still unknown . In this study the diagnostic value of the expression of MHC proteins and adhesion molecules in bile duct epithelia, the different amount of inflammatory cells around the bile ductules and the evidence of enterobacterial antigens were tested in liver tissue of patients with PBC, chronic hepatitis B and C, autoimmune hepatitis and cellular or ductopenic liver transplant rejection . There was a significant difference according MHC and adhesion molecules between PBC and rejections at the one and the cases of chronic hepatitis at the other hand . According to inflammatory infiltrate there was no difference . The enterobacterial antigen lipid-A was found more often in centrolobular hepatocytes of PBC/PSC cases but not in the portal bile duct region . The possible pathogenetic role of enterobacterial antigens in the disease are discussed.

Immunobiology, 1996, 196(4), 399 - 414
Stimulation of splenocytes in C3H/HeJ mice with Porphyromonas gingivalis lipid A in comparison with enterobacterial lipid A; Ogawa T et al.; Porphyromonas gingivalis 381 lipid A induced strong mitogenic response in splenic B cells separated from LPS-non-responsive C3H/HeJ mice as well as LPS-responsive C3H/HeN mice, by using a magnetic cell sorting system . The lipid A also exhibited mitogenic activity in splenic T cells . P . gingivalis lipid A induced lower production of interleukin-1 beta (IL-1 beta) in splenic macrophage cultures and exhibited a comparable IL-6 producing activity in splenic B cells of C3H/HeN mice as compared to Escherichia coli-type synthetic lipid A (compound 506) and monophosphoryl lipid A from Salmonella minnesota Re 595 (MLA) . Furthermore, P . gingivalis lipid A, but not compound 506 nor MLA, induced low IL-1 beta and high IL-6 production in C3H/HeJ mice . C3H/HeJ T cells in response to P . gingivalis lipid A stimulation resulted in definite IL-2 mRNA and its production, whereas IL-4 response was scarcely active in both C3H/HeN and C3H/HeJ T cells . P . gingivalis lipid A increased tyrosine, serine/threonine phosphorylation of proteins with various major induced bands in splenic B cells of both C3H/HeN and C3H/HeJ mice . Thus, P . gingivalis lipid A stimulated the splenic immunocytes of C3H/HeJ as well as C3H/HeN mice.

Scand J Infect Dis, 1996, 28(6), 601 - 8
A 6-month prospective study of hospital-acquired bacteremia in Copenhagen county; Jensen AG et al.; During a 6-month period, 892 positive blood cultures were detected in the Copenhagen County hospitals . 302 (34%) were regarded as contaminations, and of the remaining cases 419 (71%) were community-acquired and 171 (29%) hospital-acquired, giving incidence rates of 6.8/1,000 admissions and 2.8/1,000 admissions, respectively . Both frequency and rate of hospital-acquired bacteremia were lower compared to most other studies . E . coli was more commonly found in community-acquired infections, while coagulase-negative staphylococci were the organisms most often considered as a contaminant . The main causative organisms in hospital-acquired infections were S . aureus (n = 37) and E . coli (n = 34) . The proportion of polymicrobial bacteremias in this study was lower compared to most other studies (8%) . E . coli from hospital-acquired infections were resistant to ampicillin in 42% of cases, but other Enterobacteriaceae showed higher percentage of resistance to beta-lactam antibiotics . S . aureus was penicillin-resistant in 92% of cases, but no methicillin-resistant strains were isolated . The frequency of antibiotic resistance was low compared to reports from other countries . A total of 136 hospital-acquired cases were followed prospectively . 61% of the patients were male and 46% were > or = 60 years of age . Most patients had predisposing diseases, 90% had foreign body and/or recent surgery performed, and 74 (54%) had an intraveneous catheter . The portal of entry was known in 132 (97%) of the cases, the most common being the urinary tract (42%), followed by an intravenous catheter (30%) . The prevalence of urinary tract catheters gave an increased number of cases with E . coli bacteremia . The mortality was 16%.

Scand J Infect Dis Suppl, 1996, 101, 33 - 43
Are all beta-lactams created equal?
Livermore DM.
beta-Lactams are the largest antibiotic family, but are readily compromised by resistance . The result has been a cat-and-mouse game between chemists and bacteria, with the compounds repeatedly modified to overcome emergent resistance . With penicillins, it is possible to obtain spectrum, or beta-lactamase stability, but difficult to combine both . In general, it is better to protect a labile penicillin with an inhibitor, though this strategy is limited by the absence of good inhibitors of AmpC beta-lactamases . Combining spectrum and beta-lactamase stability proved easier with cephalosporins, but it is difficult to cover enterobacteria, anaerobes, non-fermenters and staphylococci with a single compound, and enterococci are consistently resistant . Carbapenems allow the broadest spectrum of available beta-lactams . Less equal or predictable than initial spectrum is how rapidly resistance emerges . This point is especially important pertinent to beta-lactamases; PBP changes compromise all beta-lactams . Spread of plasmidic beta-lactamases destroyed the utility of penicillin G against staphylococci and that of anti-gram-negative penicillins against enterobacteria . Resistance to 'beta-lactamase-stable' cephalosporins has recently spread in enterobacteria, mediated by hyperproduction of AmpC beta-lactamases and extended-spectrum TEM and SHV types . Carbapenems were launched shortly after 3rd-generation cephalosporins, but beta-lactamase-mediated resistance has emerged more slowly . Nevertheless, recent reports of zinc carbapenems in gram-negative bacteria from Japan are disturbing.

Scand J Infect Dis Suppl, 1996, 101, 17 - 20
Antimicrobial susceptibility and extended-spectrum beta-lactamases of Hong Kong isolates of enterobacteriaceae; Lyon DJ et al.; High levels of resistance to extended-spectrum cephalosporins have been reported in the Western Pacific area but data on the prevalence of extended-spectrum beta-lactamases (ESBLs) is more scanty . 370 Hong Kong blood culture isolates of Enterobacteriaceae isolated in the years 1990 and 1995 were evaluated for resistance to 15 antibiotics and the presence of ESBLs . 1995 isolates showed increased levels of resistance for beta-lactams, trimethoprim, ciprofloxacin and aminoglycosides . The proportion of E . coli harbouring ESBLs was 1/61 (1.6%) in 1990 and 2/77 (2.6%) in 1995 . The prevalence in Klebsiella spp . rose from 1/36 (2.8%) in 1990 to 5/49 (10.2%) in 1995 . ESBLs were found most frequently in Enterobacter spp . and were present in 7/29 (24.1%) of 1990 isolates and 5/22 (22.7%) of 1995 isolates . ESBLs may not be detectable in routine susceptibility testing and appropriate screening methods such as double disc screening tests are necessary to accurately determine ESBL prevalence.

Probl Tuberk, 1996, (4), 41 - 3
{Changes in the microflora of the sputum and the bronchoalveolar fluid in patients with acute and protracted pneumonias}; Landyshev SIu; A quantitative technique was used to microbiological study of sputum in 110 patients with acute pneumonia and 56 with advanced pneumonia, in 38 of them, their bronchoalveolar lavage fluid was simultaneously examined . In acute pneumonia, Pneumococcus was most commonly (71.8%) cultured, frequently in combination with other microorganisms, mainly with Neisseria and Enterobacteriaceae . These patients were found to have higher pneumococcal cultivation rates (83.0%) in the bronchoalveolar lavage fluid . Following 3 weeks of etiotropic therapy, the pneumococcal cultivation rates dropped to 10.8% . Pneumococcus also occupied the leading place (69.6%) in the etiology of advanced pneumonia, Mycoplasma pneumoniae was detected by the indirect immunofluorescence test in 28.5% of patients . After 3-week therapy, the cultivation rates for Pneumococcus decreased to 23.0%, its association with other microbes being more frequently observed . At the same time there was a rise in the detection rate of Mycoplasma antigen, which could cause advanced pneumonia.

Med Pr, 1996, 47(5), 445 - 53
{Influence of vapours of paint and toxic dusts on mucous membranes of the upper airways in paint and varnish factory workers}; Pospiech L et al.; Macroscopic, cytologic and bacteriologic conditions of mucous membranes of the upper airways in workers (n = 146) of the Polifarb Factory, Wroclaw, exposed to dusts and solvent vapours used in the paint and varnish production was estimated . In 89% of the workers, pathologic changes in throat mucous membranes were observed . Three types of macroscopic changes were distinguished . In workers with the shortest period of employment, laryngeal oedema congestion alteration was diagnosed, and atrophic changes with medium intensity were observed in workers employed for a long period . It was found that cytologic changes in the nose mucous membrane depended on the duration of exposure . Inflammation cytograms appeared during the first period of exposure to the substances discussed . The longer period of exposure, the more clear features of metaplasia squamous epithelium . The composition of the nose and throat bacterial flora changed according to the length of employment . An increased growth of G(-) genera Enterobacter, Klebsiella, Proteus, Escherichia and Candida fungi was found in workers with long period of employment.

Antibiot Khimioter, 1996, 41(9), 57 - 9
{Chronic osteitis--modern therapy}; Vittver V et al.; The results of the clinical trials with ofloxacin in the treatment of osteitis are presented . The drug was used according to 3 regimens: 200 mg thrice a day, 200 mg twice a day and 400 mg once a day for 6 to 24 months . The disease diagnosis was based on the bacteriological investigation of the biopsy specimens and hemocultures . The isolates were shown to be susceptible to ofloxacin . The majority of the patients (78 per cent) was treated with ofloxacin after the preliminary surgical operations . The treatment was started with the ofloxacin intravenous administration in a dose of 400 mg followed by the drug oral use in the same dose once a day for at least 14 days . The most frequent causative agents were: Staphylococcus aureus (52 per cent of the cases) and Staph.epidermidis (13.7 per cent of the cases) which were eradicated in 91.7 and 93.9 per cent of the cases respectively when the ofloxacin MICs were 0.26 and 0.22 mg/l respectively . The number of the gram-negative isolates on the whole amounted to 72.56 per cent and that of the gram-negative isolates amounted to 27.46 per cent of all the pathogens . As for the latter Pseudomonas aeruginosa and Enterobacter spp . were the most frequent (11.14 and 5.4 per cent respectively) . The eradication of the pathogens amounted to 80.6 and 94.43 per cent respectively when the drug MICs were 1.78 and 0.42 mg/l respectively . The regimen with the drug oral use in a dose of 400 mg once a day proved to be the most expedient . It provided the complete therapeutic effect, minimum cost and maximum comfort for the patients.

Diagn Microbiol Infect Dis, 1996 Jan, 24(1), 53 - 7
Two investigational glycylcyclines, DMG-DMDOT and DMG-MINO . Antimicrobial activity studies against gram-positive species; Johnson DM et al.; DMG-DMDOT (CL-331,002 OR CL-331,928) and DMG-MINO (CL-329,998 or CL-344,677) are two new semisynthetic tetracyclines called glycylcyclines, with a broad spectrum of activity and includes Enterobacteriaceae, Gram-positive cocci, JK diphtheroids, and Bacillus cereus . Potent activity was demonstrated against all Streptococcus spp . strains {minimum inhibitory concentrations} (MIC90S) 0.06-0.25 micrograms/ml) and staphylococci (oxacillin susceptible ans resistant; MIC90S 0.12-2 micrograms/ml) . Both glycylcyclines (MIC90, 0.06 micrograms/ml) were more potent than minocycline (MIC90 8 micrograms/ml) against Enterococcus faecium, many of which were vancomycin resistant (116 strains) . Organisms with minocycline MICs at > or = 8 micrograms/ml (Staphylococcus aureus, enterococci, beta-hemolytic streptococci, and pneumococci) had glycylcycline MIC results ranging from 0.06 to 0.5 micrograms/ml (e.g., apparent use against existing tetracycline-resistance phenotypes) . Drugs in this class appear promising for therapy of infections caused by Gram-positive species now testing resistant to contemporary antimicrobial agents, and further development of compounds in this class is encouraged.

Microbiol Immunol, 1996, 40(10), 773 - 5
Detection and identification of Yersinia pestis by polymerase chain reaction (PCR) using multiplex primers; Tsukano H et al.; A PCR method for detection of Yersinia pestis-virulence determinants by the use of multiplex primers was developed . Four pairs of oligonucleotide primers were designed from each gene of three kinds of virulent plasmids and a chromosomal DNA; 60-Md plasmid-located gene (caf1)encoding Y.pestis-specific capsular antigen fraction 1, a Y.pestis-specific region of a yopM gene encoded on 42-Md virulent plasmid, a plasminogen activator gene (pla) encoded on Y.pestis-specific 7-Md plasmid and an invasin protein gene (inv) encoded on chromosomal DNA . This multiplex-primer system was specific for the detection of Y.pestis among pathogenic Yersinia species and other enterobacteriaceae having antigens common to Y.pestis . Since this method is simple and safe, it will be useful to identify and confirm Y.pestis in cases of emergency and for the surveillance of epidemics.

Bacteriol Virusol Parazitol Epidemiol, 1996 Jan-Jun, 41(1-2), 33 - 6
{Enterobacteria of the genera Salmonella, Shigella and Yersinia with an etiological role in acute diarrheal disease}; Vaida T et al.; In a study made during 5 years, from 1990 to 1994 on 8363 subjects with acute diarrhoea disease, we found 486 cases (5,81%) in which the etiologic agent was belonging to a species of enterobacteria; as follows: Shigella (69,13%), Salmonella (27,78%) and Yersinia enterocolitica (3,08%), and which were isolated predominantly in children with ages ranging from 6 months to 7 years . The serogroups of Shigella most often isolated were Shigella sonnei, in 196 patients (35,11%) . Regarding the cases with Salmonella, in most of the cases Salmonella enteritidis was isolated (60,74%) followed by Salmonella typhimurium and other Salmonellae from the serogroup BO (23,70%) . In the last 2 years (1993 and 1994), in 12 cases Yersinia enterocolitica was isolated; together with Salmonella enteritidis and Salmonella typhimurium, they could cause infections associated with consume of infected food.

Vet Res, 1996, 27(6), 607 - 12
Prevalence of microorganisms in dead mink kits from Aleutian-disease-infected and non-infected farms; Martino PE et al.; Bacterial and fungi were isolated from different tissues (brain, liver, heart) taken from 81 dead newborn mink originating from Aleutian disease (AD) infected and AD-non-infected farms . Of the 123 isolates obtained, 96% were bacterial isolates (predominantly Gram-negative) and 4% were fungi . The prevalence of microorganisms appeared less common in kits from AD-non-infected farms (55%) than from AD-infected farms (73%), although the difference was not significant . The liver was the most highly infected site in both groups and generally was only infected by one microorganism species . Proteus spp (23%), Escherichia coli (16%), Staphylococcus aureus (11%) and Enterobacter cloacae (9%) were the most frequently isolated germs . These findings are similar to those of other studies but the role of these microorganisms as specific pathogens or secondary invaders remains controversial.

Ann Biol Clin (Paris), 1996, 54(6), 243 - 52
Advances in immunochemical detection of microorganisms; Hock B; Immunology and microbiology have been linked together since their infancies . The discovery more than 100 years ago that antibodies (Abs) constitute one of the pillars of the body's defense against bacteria and viruses led immediately to the development of serological tests for diagnosis and identification of microorganisms . More recent approaches are based on immunoassay technology, which does not require cross-linking of antigens by Abs . High sensitivity results from the use of labels, such as fluorescent dyes or enzymes, for the detection of antigen binding by Abs . As an example, the quantification of members of the Enterobacteriaceae in drinking water using enzyme immunoassays (Elisa) is presented, which is now available as a DIN standard . Related techniques such as dipstick or dot blot tests originated from the necessity of shortening the analysis time . Immunofluorescence flow cytometry represents the most sophisticated development of this technology to date . A major technological leap is expected from immunosensors, miniaturized measuring devices that selectively detect their targets and provide concentration-dependent signals . When Abs as part of the receptor unit bind their ligands, there is a variation in optical properties, electric charge, mass, or heat, which can be detected directly, ie without tracers, by a variety of transducers . Since sensitivity is directly related to the affinity of the ligand binding, high sensitivity excludes reversibility . Immunochemical methodology is still limited by the availability of selective and sensitive Abs . Future progress will be significantly accelerated by the application of recombinant techniques for Ab production . The main emphasis is directed toward the generation of recombinant Ab libraries, as they are already available for the generation of anti-HIV Ab fragments . It is not surprising therefore that immunochemical methodology, together with PCR-based techniques, belongs to the most promising branch of modern diagnosis.

Med Dosw Mikrobiol, 1996, 48(1-2), 87 - 94
{Evaluation of antibacterial and antitoxic activity of normal human immunoglobulin for intravenous use (IVIG)}; Bucholc B et al.; In the present study, human immunoglobulins for intravenous use (IVIG), were tested for contents of diphtheria antibodies, antistreptolysin O, antistaphylolysin and antibody level of endotoxin of B . pertussis, enterobacterial common antigen and group B Streptococci . It was shown that all examined immunoglobulin preparation contained antibodies against all tested antigens . Our investigation revealed differences between IVIG preparations and IVIG lots . Basing on these results, we know that the biological activity of Bioglobulin is the same as biological activity of other IVIG preparations produced by foreign manufactures.

Med Dosw Mikrobiol, 1996, 48(1-2), 61 - 70
{The study of drug resistance in aerobic and anaerobic bacterial flora to selected antibacterial drugs}; Michalska W et al.; The aim of the study to determine the resistance to certain antibacterial drugs of the aerobic and anaerobic bacterial flora isolated from patients operated on for acute abdominal infections . The resistance was investigated by the disc diffusion method . Among the isolated aerobes Enterobacteriaceae, Enterococcus spp, Pseudomonas spp . Staphylococcus spp were most frequent, and in the group of anaerobes the most frequent were Bacteroides spp, Peptostreptococcus spp and Peptococcus spp . The sensitivity to ciprofloxacin, gentamicin and cefoperazone was tested in 492 aerobic strains, and the sensitivity of cefuroxime was tested in 387 strains . In the group of anaerobes the sensitivity to ciprofloxacin and cefoperazone was tested in 239 strains, and in 187 and 176 strains the sensitivity to cefuroxime and metronidazole respectively was tested . Only 94 aerobic strains and 32 anaerobic strains were additionally tested for augmentin, ceftriaxone, ceftazidime, imipenem, clindamycin and doxycycline . Imipenem was found to be the most active drug against aerobic and anaerobic bacteria . Clindamycin showed a very high activity against anaerobes but was significantly less active against aerobes . Only a small proportion of the tested aerobic strain (11.2%) were resistant to ciprofloxacin, while most anaerobic strains (66.5) were resistant to this antibiotic . Metronidazole was active against about 100% of anaerobes . Augmentin had a high activity against gram-positive cocci and was less active against gram-negative rods and anaerobes . A high proportion of aerobic and anaerobic strains were resistant to ceftriaxone, ceftazidime, cefuroxime and doxycycline . Gentamicin showed a sufficient activity against the tested aerobic strains (33.9% were resistant).

Med Dosw Mikrobiol, 1996, 48(1-2), 31 - 7
{Evaluation of the usefulness of the latex test for detection and identification of O-antigens of Yersinia enterocolitica and Yersinia pseudotuberculosis}; Jagielski M et al.; In the study latex reagents of own production were used, in which latex of 0.9 microns particle diameter was coated with globulins salted out from rabbit sera against Y . enterocolitica groups 03, 05, 06, 08 and 09, and Y . pseudotuberculosis groups I and III . The study was carried out with five standard strains of Y . enterocolitica representing groups 03, 05, 06, 08 and 09, two standard strains of Y . pseudotuberculosis representing group antigens I and III, and 110 strains identified as Yersinia organisms, including 83 strains of Y . enterocolitica, 12 - Y . pseudotuberculosis, 7 - Y . frederiksenii, 4 - Y . intermedia, 2 - Y . kristensenii, and 2 strain of unknown species . Besides that, 54 laboratory strains of Enterobacteriaceae not belonging to Yersinia genus were studied . Latex test was done with bacterial suspensions of 6 x 10(8) cell/ml density of standard Yersinia strains and laboratory strains of Enterobacteriaceae, and with 110 Yersinia strains cultured in broth and peptone water media with tryptophan 0.1% . It was found that the prepared latex reagents reacted in the agglutination test on slide only with the suspensions of homologus . Yersinia organisms but not with suspensions of other Enterobacteriaceae . Among 83 strains identified as Y . enterocolitica 24 belonged to group 03, 19 to 05, 10 to 06, 2 to 08, 2 to 09 . In the 12 strains identified as Y . pseudotuberculosis 9 belonged to group I and 2 to group III . The study showed that the latex reagents prepared by us can be used for identification of O-antigen of Yersinia organism immediately in liquid media.

Indian J Med Res, 1996 Jan, 103, 58 - 61
Nosocomial infection due to enterobacter cloacae in a tertiary care hospital in northern India; Banerjee G et al.; A total of 151 Enterobacter cloacae strains isolated from clinical samples (n = 139) and the hospital environment (n = 12) at a tertiary care hospital in northern India during January to October 1993, were analysed . The maximum isolations were during May (n = 24), June (n = 23) and July (n = 22) . Urinary tract infection (n = 56) was the most common complication of E . cloacea infection followed by wound infection (42), respiratory tract infection (23) and bacteraemia/septicaemia (18) . The frequency of resistance to different drugs was ampicillin 77.4 per cent, cotrimoxazole 79.5 per cent, gentamicin 57.5 per cent, cefotaxime 47 per cent and ofloxacin 36 per cent . Sixty three (41.7%) strains exhibited resistance to multiple drugs . Environmental isolates from bed, hospital diet, hand swab and water from a leaking drain pipe in a ward showed the same resistance pattern . A single index strain could not be identified using phage and biotyping, indicating that a variety of strains were responsible for the nosocomial infection . Adoption of strict aseptic measures and repair of the pipe brought down the infection rate.

J Basic Microbiol, 1996, 36(5), 351 - 4
Phylogenetic relationships of entomopathogenic nematophilic bacteria: Xenorhabdus spp . and Photorhabdus sp; Suzuki T et al.; Phylogenetic relationships of Xenorhabdus spp . and Photorhabdus sp . were investigated on the basis of 16S rRNA gene sequences . Xenorhabdus spp . and Photorhabdus sp . were grouped together with Proteus vulgaris and Arsenophonus nasoniae . This group was distant from other members of the family Enterobacteriaceae . Xenorhabdus japonicus, previously proposed as a new species, was nearly located to Xenorhabdus nematophilus . Signature nucleotides of X . japonicus were identified that distinguish it other members of the family Enterobacteriaceae.

Annu Rev Microbiol, 1996, 50, 213 - 57
Regulation of pectinolysis in Erwinia chrysanthemi; Hugouvieux-Cotte-Pattat N et al.; Erwinia chrysanthemi is an enterobacterium that causes various plant diseases . Its pathogenicity results from the secretion of pectinolytic enzymes responsible for the disorganization of the plant cell wall . The E . chrysanthemi strain 3937 produces two pectin methylesterases, at least seven pectate lyases, a polygalacturonase, and a pectin lyase . The extracellular degradation of the pectin leads to the formation of oligogalacturonides that are catabolized through an intracellular pathway . The pectinase genes are expressed from independent cistrons, and their transcription is favored by environmental conditions such as presence of pectin and plant extracts, stationary growth phase, low temperature, oxygen or iron limitation, and so on . Moreover, transcription of the pectin lyase gene responds to DNA-damaging agents . The differential expressions of individual pectinase genes presumably reflect their role during plant infection . The regulation of pel genes requires several regulatory systems, including the KdgR repressor, which mediates the induction of all the pectinolysis genes in the presence of pectin catabolites . KdgR also controls the genes necessary for pectinase secretion and other pectin-inducible genes not yet characterized . PecS, a cytoplasmic protein homologous to other transcriptional regulators, can bind in vitro to the regulatory regions of pectinase and cellulase genes . The PecT protein, a member of the LysR family of transcriptional regulators, represses the expression of some pectinase genes and also affects other metabolic pathways of the bacteria . Other proteins involved in global regulations, such as CRP or HNS, can bind to the regulatory regions of the pectinase genes and affect their transcription.

Biochimie, 1996, 78(4), 277 - 87
Comparative analysis of the cya locus in enterobacteria and related gram-negative facultative anaerobes; Trotot P et al.; Comparison of the cya loci (cya codes for adenylyl cyclase (AC)) from a variety of phylogenetically divergent facultative anaerobic Gram-negative bacteria reveals conserved sequence features . The entire locus structure in enterobacteria is preserved, including two major promoters (a conserved cya strong promoter, P2, and a divergent promoter for a heme biosynthetic operon, hemCD) present in the upstream region of the cya gene . The region between hemC and cya is much longer in Proteus mirabilis than in other enterobacteria, and lacks the P1 upstream cya promoter . In Aeromonas hydrophila the cya promoter (the strong P2 promoter in E coli) is preserved, including a putative GATC methylation site situated immediately downstream from the -10 box . Each cya frame analyzed uses TTG as the translation start codon and is preceded by an unusual ribosome binding site . This suggests that a lower translation efficiency of the cya transcript could be the result of some selection pressure . This has been substantiated by in vitro mutagenesis and by selection of up mutations which all map at the cya ribosome binding site . In enterobacteria the cyaY frame is the only conserved reading frame downstream of cya, with the orientation opposite to that of cya . This organization is not preserved in Aeromonas . Experiments involving fusions with the lacZ gene demonstrated that cyaY is expressed . Finally, comparison of the different polypeptide sequences of ACs permits discussion of important features of the catalytic and regulatory centers of the protein.

Scand J Infect Dis, 1996, 28(3), 293 - 6
A hospital outbreak of high-level beta-lactam-resistant Enterobacter spp.: association more with ampicillin and cephalosporin therapy than with nosocomial transmission; Walder M et al.; We studied an 8 month outbreak of a 7-fold increased isolation rate of high-level beta-lactam-resistant Enterobacter spp . from clinical infections (20 patients, 22 isolates: 20 E . cloacae, 2 E . aerogenes) . In a case-control analysis the occurrence of resistant Enterobacter spp . was found to be associated with treatment with multiple antibiotics (p = 0.03), broad-spectrum beta-lactam agents (p = 0.0001) including ampicillin (p = 0.04), and cephalosporins (cefuroxime and cefotaxime, p = 0.004) . Biochemical fingerprinting and pulsed-field gel electrophoresis (PFGE) typing showed no identity between the resistant isolates, indicating that neither cross-infection nor nosocomial transmission from a common source was the immediate cause of the problem . The outbreak was not paralleled by the overall Enterobacter spp . isolation rate or the antibiotic usage pattern in the hospital . Thus, the underlying cause of the outbreak remained obscure.

Acta Microbiol Immunol Hung, 1996, 43(1), 19 - 24
Microbial pathogenicity factors as parts of global regulatory networks . (A short review); Hacker J; Pathogenic bacteria differ from non-pathogenic isolates by the expression of so-called virulence or pathogenicity factors, including adherence molecules, toxins, capsules and others . The majority of the genes encoding pathogenicity factors are not expressed constitutively, but rather undergo environmental regulation or random regulatory events . In enterobacteria, such virulence associated genes are often corregulated with determinants influencing metabolic properties . By analyzing the structure and regulation of genes which are essential for the urovirulence of pathogenic Escherichia coli, we were able to show that genes coding for alfa haemolysin, cytotoxic necrotizing factor I and P fimbriae are located on large instable DNA regions, termed "pathogenicity islands" . These islands also comprise regulatory genes which are able to activate adherence specific genes that are not part of those islands . In addition, pathogenicity islands are associated with tRNA loci . One of these tRNA genes, which codes for a minor leucin tRNA and is therefore termed leuX, acts as a global regulator . It influences the expression of various genes of pathogenic E . coli, including adherence specific loci, enterobactin genes, flagella specific gene clusters and determinants involved in serum resistance.

Antimicrob Agents Chemother, 1996 Jan, 40(1), 105 - 9
Serum bactericidal activities and comparative pharmacokinetics of meropenem and imipenem-cilastatin; Dreetz M et al.; The pharmacokinetics and serum bactericidal activities (SBAs) of imipenem and meropenem were investigated in a randomized crossover study . Twelve healthy male volunteers received a constant 30-min infusion of either 1 g of imipenem plus 1 g of cilastatin or 1 g of meropenem . The concentrations of the drugs in serum and urine were determined by bioassay and high-pressure liquid chromatography . Pharmacokinetic parameters were based on an open two-compartment model and a noncompartmental technique . At the end of infusion, the mean concentrations of imipenem and meropenem measured in serum were 61.2 +/- 9.8 and 51.6 +/- 6.5 mg/liter, respectively; urinary recoveries were 48.6% +/- 8.2% and 60.0% +/- 6.5% of the dose in 12 h, respectively; and the areas under the concentration-time curve from time zero to infinity were 96.1 +/- 14.4 and 70.5 +/- 10.3 mg.h/liter, respectively (P < or = 0.02) . Imipenem had a mean half-life of 66.7 +/- 10.4 min; that of meropenem was 64.4 +/- 6.9 min . The volumes of distribution at steady state of imipenem and meropenem were 15.3 +/- 3.3 and 18.6 +/- 3.0 liters/70 kg, respectively, and the mean renal clearances per 1.73 m2 were 85.6 +/- 17.6 and 144.6 +/- 26.0 ml/min, respectively . Both antibiotics were well tolerated in this single-dose administration study . The SBAs were measured by the microdilution method of Reller and Stratton (L . B . Reller and C . W . Stratton, J . Infect . Dis . 136:196-204, 1977) against 40 clinically isolated strains . Mean reciprocal bactericidal titers were measured 1 and 6 h after administration . After 1 and 6 h the median SBAs for imipenem and meropenem, were 409 and 34.9 and 97.9 and 5.8, respectively, against Staphylococcus aureus, 19.9 and 4.4 and 19.4 and 4.8, respectively, against Pseudomonas aeruginosa, 34.3 and 2.2 and 232 and 15.5, respectively, against Enterobacter cloacae, and 13.4 and 2.25 and 90.7 and 7.9, respectively, against Proteus mirabilis . Both drugs had rather short biological elimination half-lives and a predominantly renal route of elimination . Both carbapenems revealed high SBAs against clinically important pathogens at 1 h; meropenem had a higher SBA against E . cloacae and P . mirabilis, and the SBA of imipenem against S . aureus was greater than the SBA of meropenem.

Acta Med Croatica, 1996, 50(1), 37 - 44
Bone and joint infections caused by gram-negative bacteria; Kucisec-Tepes N; Infections of the bones and joints caused by gram-negative bacteria from the family Enterobacteriaceae account for 10%-15% . This family usually cause opportunistic infections, due to a low virulence factor, host and environmental factors . Gram-negative bacteria cause osteomyelitis, infectious arthritis and Reiter's syndrome . The family Enterobacteriaceae belong to the physiological flora of man and cause opportunistic and hospital infections . In order to reach an accurate etiologic diagnosis, it is therefore important for the samples for bacteriologic examination to be properly taken . The quality of samples depends on the type, time and method of sampling, duration of the disease prior to sampling, and antimicrobial therapy . Essential samples are bone biopsy, synovial fluid aspirate and blood culture . Improper interpretation of bacterial isolates and failure to exclude colonization are the most common errors encountered in daily routine.

Ann Urol (Paris), 1996, 30(3), 131 - 8
Transurethral laser therapy and urinary tract infections; Miller J et al.; To date transurethral laser ablation of the prostate (TULAP) in benign prostatic hyperplasia (BPH) is the commonest form of transurethral laser surgery . The invention of the so-called "sidefire" laser fibre was the prerequisite condition for effective transurethral laser ablation of the prostate . Since the first transurethral laser ablation in human BPH was performed by Costello in September 1990, a multitude of urologists have adopted this technique . In the meantime, a great many studies have been carried out and a lot of data have been published . The initial, to some extent euphoric, enthusiasm of some urologists as well as some patients, especially in the USA and Europe, has turned into a more critical reflection . There is no doubt at all that TULAP is a feasible alternative treatment method with reasonable results . Especially in the high-risk patient, there is neither severe blood loss nor an uptake of irrigation fluid . It is also beneficial to allow unlimited treatment in patients on anticoagulant medication . Nevertheless, the value of TULAP in comparison to transurethral electroresection of the prostate (TURP), generally accepted as the "gold-standard" in the surgical therapy of BPH, remains unclear . A final assessment will only be possible when further data on mortality, short and long term morbidity and outcome with this method have been presented . Strong evidence exists that the operation can be performed without blood loss and uptake of irrigation fluid . A further advantage seems to be preservation of sexual function, especially anterograde ejaculation in the majority of patients, in comparison to the "gold-standard" TURP . In most studies, the value of TULAP is further compared with regard to the elimination of obstruction by means of pressure-flow-studies . The aspect most frequently neglected by all investigators to date is the frequency and severity of urinary tract infections (UTI) in patients in whom TULAP is performed . Basically, UTI in the form of cystitis, ascending infections such as male adnexitis or pyelonephritis, prostatitis of the remaining parts of the prostate and catheter-induced urethritis are associated with transurethral surgery in general . Certain data indicate an age-related frequency of UTI . From a rate of approximately 1% of UTI in infants, the frequency rises to 30% in the 8th decade of life . According to these data, one can expect that in a study of TULAP in high risk patients, most of whom are elderly, a large number present for surgery with a preexisting UTI . Other data demonstrate that after 4.5 days 50% and more of patients with an indwelling catheter develop an ascending UTI, although a closed urinary drainage system has been used . In most cases enterobacteriaceae, in 80% Escherichia coli, are detected . Especially in TULAP, a period of prolonged catheterisation has to be expected in the majority of patients . The risk of UTI in the perioperative phase is therefore expected to be higher . There are several higher risks and possibilities of complications in transurethral surgery in patients with UTI . Taking this into account, all our patients routinely undergo low dose antibiotic prophylactic treatment . The frequency of infections of the remaining parts of the prostate after prostatic surgery is strongly correlated to the flow characteristics in the prostatic urethra and to the amount of destruction of the prostatic tissue . Here are further reasons for a higher risk of infection after TULAP . Due to the fact that the prostatic tissue is not removed by a clear cut, but coagulated by laser beam, a rough surface due to tissue necrosis results . This is an ideal culture medium for bacteria aggravated by the disturbed laminar flow in the prostatic urethra, which favours an intraprostatic reflux of infected urine . There is evidence that UTI are the most important factor of morbidity during the first weeks after TULAP because of their bothersome symptoms.(ABSTRACT TRUNCATED)

Ann Urol (Paris), 1996, 30(3), 118 - 23
{Urinary infection in urolithiasis patients in the Epirus district (northeastern Greece)}; Giannakopoulos X et al.; The relationship between renal stones and urinary tract infection is frequent but not well-known . In this study, urinary tract infection was found in 12% of renal stone formers . It is four times more common in females than in males . Urea splitting bacteria (Proteus, Klebsiella, Staphylococcus and Pyocyaneus) lead to stone formation . They were identified in 72% of cases . Proteus was predominant and the organism most frequently found in staghorn stone formers . Other non urea-splitting bacteria (E . coli, Enterobacter, Streptococcus) were observed in 25% to 30% of cases . The percentage of the various bacteria varies according to the degree of resistance to therapy and the patients sex.

Khirurgiia (Mosk), 1996, (2), 64 - 6
{Treatment of appendiceal peritonitis}; Tarshis VE et al.; The results of treatment of 223 patients with acute appendicitis, complicated with advanced (51) and local (172) peritonitis have been analysed . Antibacterial treatment was conducted with account to the results of bacteriological analysis of the peritoneal exudate . Enterobacteria and non-spore anaerobic microorganisms, sensitive to the 2d and 3d generation cephalosporins, aminoglycosides and metronidazole, were prevailing . Non-use of abdominal drains and provisional wound sutures made it possible to decrease the duration of in-hospital period to 12.7 days (15.4 days in general peritonitis; 11.8 days local peritonitis) . The mortality rate was 0.4%.

Chemotherapy, 1996 Jan-Feb, 42(1), 1 - 10
Cefetamet pivoxil: comparable evaluation with other orally available antibiotics against selected species of respiratory pathogens; Speciale A et al.; Cefetamet pivoxil, the prodrug ester of cefetamet, is a new third-generation cephalosporin with a broad spectrum of activity . The in vitro activity of cefetamet was superior to that of cefaclor, ceftibuten, amoxicillin plus clavulanic acid, and amoxicillin alone when tested against 403 strains of freshly isolated upper and lower respiratory tract pathogens . Cefetamet killed 100% Haemophilus influenzae and H . parainfluenzae, including beta-lactamase-producing strains, at < or = 0.25 mg/l, Streptococcus pyogenes and S . pneumoniae at < or = 0.5 mg/l, S . agalactiae at < or = 0.1 mg/l, and streptococci at < or = 2.0 mg/l . Moreover, at < or = 4 mg/l (breaking point), cefetamet was also highly effective against Escherichia coli (94%), Klebsiella pneumoniae (92%), K . oxytoca (91%) and, at 1 mg/l, against Moraxella catarrhalis (90%), including beta-lactamase-producing strains . Furthermore, time-killing analyses at 4 x MIC demonstrated that cefetamet was bactericidal against beta-lactamase-producing H . influenzae, M . catarrhalis, and K . pneumoniae within 6 h and S . pneumoniae within 4 h . Hydrolysis studies confirmed cefetamet's stability to TEM1 and SHV1, the most common enterobacterial beta-lactamases.

J Clin Microbiol, 1996 Jan, 34(1), 179 - 81
Evaluation of new computer-enhanced identification program for microorganisms: adaptation of BioBASE for identification of members of the family Enterobacteriaceae; Miller JM et al.; We report the use of BioBASE, a computer-enhanced numerical identification software package, as a valuable aid for the rapid identification of unknown enteric bacilli when using conventional biochemicals . We compared BioBASE identification results with those of the Centers for Disease Control and Prevention's mainframe computer to determine the former's accuracy in identifying both common and rare unknown isolates of the family Enterobacteriaceae by using the same compiled data matrix . Of 293 enteric strains tested by BioBASE, 278 (94.9%) were correctly identified to the species level; 13 (4.4%) were assigned unacceptable or low discrimination profiles, but 8 of these (2.7%) were listed as the first choice; and 2 (0.7%) were not identified correctly because of their highly unusual biochemical profiles . The software is user friendly, rapid, and accurate and would be of value to any laboratory that uses conventional biochemicals.

J Clin Microbiol, 1996 Jan, 34(1), 126 - 9
Comparative evaluation of BACTEC aerobic Plus/F and Septi-Chek Release blood culture media; Rohner P et al.; The BACTEC 9240 (Becton Dickinson, Sparks, Md.) automated blood culture system is based on the continuous monitoring of CO2 production by means of a fluorescent sensor attached to the bottom of culture vials . We compared the performance of the BACTEC aerobic Plus/F medium to that of the Septi-Chek Release medium (Becton Dickinson, Sparks, Md.), a manual biphasic blood culture system . Sets consisting of BACTEC aerobic Plus/F and Septi-Chek Release vials inoculated with similar volumes (7 +/- 2 ml) were evaluated . In the laboratory, systems were equipped and analyzed according to the manufacturer's recommendations . The BACTEC and Septi-Chek vials were incubated at 35 degrees C for 5 days . A total of 6,116 compliant sets were obtained from 1,972 adult patients (3.1 cultures per patient) . Of these, 731 (12%) were culture positive, including 612 (10%) that yielded at least one pathogen, and 143 (2%) were considered to be contaminated . Of the 672 pathogenic organisms detected, 524 were isolated from the BACTEC aerobic Plus/F medium and 574 were isolated from the Septi-Chek Release medium, 428 organisms grew in both media, 96 organisms grew only in the BACTEC aerobic Plus/F medium, and 146 organisms grew only in the Septi-Chek Release medium (P = 0.001) . Haemophilus spp . were isolated more often (P = 0.03) from the BACTEC aerobic Plus/F medium; however, more Streptococcus anginosus organisms (P = 0.02), members of the Enterobacteriaceae family (P < 0.03), and gram-negative anaerobes (P = 0.03) were isolated from the Septi-Chek Release medium . Pathogenic organisms were detected significantly earlier (P < 0.0001) with the BACTEC aerobic Plus/F medium in conjunction with the BACTEC 9240 instrument than with the Septi-Chek Release medium.

J Clin Microbiol, 1996 Jan, 34(1), 68 - 70
Epidemiological typing of Flavimonas oryzihabitans by PCR and pulsed-field gel electrophoresis; Liu PY et al.; Flavimonas oryzihabitans has emerged as a potential nosocomial pathogen in recent years . The typing method for characterization of this species has never been reported before . Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based PCR were used to generate DNA fingerprints for 14F . oryzihabitans isolates obtained from eight episodes of nosocomial infections during a 2-year period . Both techniques successfully classified these clinical isolates into eight distinct genotypes, thus indicating that all of these episodes of infections were independent . In contrast, repeated isolates from the same patient were assigned to identical genotypes . The reproducibility of both techniques was good . Therefore, we conclude that both PFGE and ERIC-PCR have comparable reproducible and discriminatory powers for the typing of F . oryzihabitans and may be useful for clarifying the epidemiology of this species; however, ERIC-PCR has the advantages of both speed and simplicity.

What Is Prokaryote?, What Is Functional Genomics?, What Is Environmental Microbiology?, What Is Genome?, What Is Dna?, s, Microbes, n, Microbe, e, Bacterium, e, Microorganisms, i, Bacteriology, i, Haemophilus, o, Microbial, s, Escherichia coli, r, Bacillus, o, Microbiological, i, Staphylococcus aureus, n, Saccharomyces yeast, c, Antibiotics, i, Cell suspensions, o, Haemophilus, e, Bacteriological, c, Yeasts, o, Staphylococcus, c, Salmonella typhimurium, i, Streptomycin, n, Escherichia coli, c, Yeasts, n, Gram positive, s, S. cerevisiae, a, Streptococci, i, Haemophilus

Scientific Publications - Work Done by Microbiology Reader Bioscreen C
Agricultural Microbiology Anaerobic Microbiology Antimicrobial Susceptibility Artificial Atmosphere Bioassay of Antibiotics Biofilm Microbiology Bioreactor Technology Biotechnology Cell Biology Clinical Microbiology Environmental Microbiology Experiments with Yeast	Fermentation Food Microbiology Functional Genomics Gene Technology Growth Media Development Growth Rate and Lag Time Industrial Microbiology Medical/Pharmaceutical Field Microbiological Assay Microbiological Research Microbiology of Cosmetics go to a specific theme...	Military Microbiology Molecular Microbiology Mutagenicity and Genotoxicity Oral Microbiology Patents Postantibiotic Studies Soil Microbiology Spore Microbiology Veterinary Microbiology Waste/Wastewater Treatment Water Microbiology Wine Microbiology

� 2005 Transgalactic Ltd (manufacturer of Bioscreen C software) | Privacy Statement | P.O. Box 1393, 00101 Helsinki, Finland, phone: +358 9 85172920, fax: +358 9 8749481, e-mail: microbiology@bionewsonline.com

Last modified: May 25, 2005