Am J Vet Res, 1996 Jan, 57(1), 39 - 42 Epidemiological characteristics of bovine clinical mastitis caused by Staphylococcus aureus and Escherichia coli studied by DNA fingerprinting; Lam TJ et al.; OBJECTIVE: To study the epidemiology of clinical mastitis caused by Escherichia coli and Staphylococcus aureus by differentiating isolates with DNA fingerprinting techniques, using polymerase chain reaction . DESIGN: Milk samples were collected from cases of clinical mastitis in dairy cows . Escherichia coli and S aureus isolates from these cases were compared within and between cows and herds . SAMPLE POPULATION: Seven dairy herds with an average bulk milk somatic cell count < 150,000/ml, and incidence of cows with clinical mastitis of > 25%/y . PROCEDURE: Chromosomal DNA was isolated from E coli and S aureus strains isolated from cases of clinical mastitis, and amplified by polymerase chain reaction, using enterobacterial repetitive intergenic consensus primers for E coli and a random amplified polymorphic DNA primer for S aureus . Escherichia coli and S aureus strains were identified and differentiated, using their DNA polymorphism pattern . RESULTS: Multiple E coli genotypes were found in each of the herds . Persistent infections with E coli were sporadic . Only a limited number of different S aureus genotypes was found in each of the herds studied . Recurrent cases of S aureus mastitis were found in 25% of quarters with clinical S aureus mastitis . Comparing S aureus isolates from different herds indicated that 1 S aureus genotype was most prevalent . CONCLUSIONS: Because different quarters were infected with different genotypes, it was concluded that E coli is an environmental pathogen, and does not generally spread from quarter to quarter . The hypothesis that S aureus mastitis is a contagious disease, spreading from infected to uninfected quarters, could not be rejected. J Mal Vasc, 1996, 21 Suppl A, 152 - 7 {Treatment of an exposed femorol-popliteal bypass: ex-situ replacement}; Gouny P et al.; From December 1990 to July 1995 we performed 171 sub-inguinal revascularizations including 35 popliteal revascularizations and 146 revascularizations of an artery in the leg or foot . Five cases of infection were observed within a delay of 7 and 25 days after the operation . There were 3 men and 2 women (mean age 78 years) . Four femoro-tibial bypasses were made for critical ischaemia (2 necroses of the toes, one eschar of the heal, one stage III) . There was one femoro-popliteal bypass which was associated with a femoro-femoral for necrosis of the toes . Two bypasses were made with polytetrafluoroethylene, one with Dacron and two with the greater saphenous vein . Signs of sepsis were bleeding in 2 patients who had a venous bypass and septicaemia in 2 patients . Local skin necrosis and/or apparently infected discharge or patent pus were seen in all patients . Staphylococcus aureus was found in 4 patients and Enterobacter cloacae in one . Revascularization was done with an extra-anatomic bypass in 4 patients and with a cryopreserved in situ allograft in 1 . Mortality was 20% and amputation rate was 40% . All exposed bypasses were infected but the severity of the infection varied depending on the causal germ, general signs and ischaemia of the limb . Conservative treatment has its limits: 1) intact anastomoses, 2) absence of bleeding, 3) patent bypass, 4) absence of generalized sepsis . Results of in situ revascularization depend on the virulence of the causal germ . Radical treatment (explanation + extra-anatomic revascularization) still has indications in infected infra-inguinal bypass surgery. Int J Food Microbiol, 1996 Jan, 28(3), 411 - 8 Incidence of histamine-forming bacteria and histamine content in scombroid fish species from retail markets in the Barcelona area; Lopez-Sabater EI et al.; Incidence and diversity of histidine decarboxylating bacteria were determined in samples of tunafish, bonito and mackerel purchased at different retail markets . Histamine-forming bacteria occurred in a low proportion and always accounted for less than 0.1% of the total bacterial load in the fish samples studied . Similarly, histamine content in fish samples also was low ( < 25 ppm) and all of them met current histamine standards established by the European Union . Histamine was found in 83.3% of the tested tunafish samples with an average of 8.9 ppm . In contrast, none of mackerel samples and only 2 out of 12 of bonito showed detectable amounts of histamine . Morganella morganii and Klebsiella oxytoca were the most active histamine formers under experimental conditions, and produced on average 2765 and 1415 ppm of histamine, respectively, after incubation at 37 degrees C for 18 h . Some new histamine formers, such as Plesiomonas shigelloides, Enterobacter intermedium, Serratia marcescens, Serratia plymuthica and Serratia fonticola, have been identified . Especially Plesiomonas shigelloides would have an important role within histidine decarboxylating bacteria because it was the sole histamine former isolated that has frequently been associated with the marine aquatic environment . However, only 8-340 ppm of histamine was formed by these strains in laboratory trials. Genetika, 1996 Jan, 32(1), 140 - 5 {Presence of the binding site for the ribosomal protein L10 in the untranslated leader sequence upstream from the rplJ gene in Thermotoga maritima is evidence for autogenous control of the expression of this gene}; Paton EB et al.; Comparative analysis of the structural organization of an untranslated sequence upstream from the rplJ gene in Thermotoga maritima revealed a potential binding site for the L10 ribosomal protein . The structure of the site detected is highly homologous to that of the 23S rRNA L10 target sequence . Structural organization of the potential mRNA L10 target site detected in T . Maritima is similar to that of mRNA targets of seven species of Enterobacteria and Synechocystis PCC 6803 . Additional elements of structural homology between the mRNA and rRNA L10 targets in T . maritima are also shown . Location of the target site within the rplJ mRNA leader and ability of this region to form alternative conformations show that expression of the rplJ gene is autogenously controlled by the L10 ribosomal protein. APMIS, 1996 Jan, 104(1), 39 - 46 The adherence of oral isolates of Enterobacteriaceae to HeLa cells . An in vitro method using image analysis; Sedgley CM et al.; An in vitro model and an image analysis were designed to improve on existing quantification methods in the assessment of the adherence of Enterobacteriaceae to human epithelial cell monolayers . Adherence to HeLa cell monolayers of three oral isolates and one type strain from each of four species of Enterobacteriaceae over two incubation time periods was examined . Correction for actual cell area and a cube root transformation of the data to stabilize variance were applied . While behaviour varied between strains within species, E . cloacae was the most, and K . pneumoniae the least, adherent species irrespective of the incubation period . Increasing the incubation period from 30 min to 60 min resulted in greater adherence for E . cloacae, E . coli, and C . freundii, but not K . pneumoniae strains . The method permits the reliable measurement and valid analysis of the adherence of Enterobacteriaceae to cultured epithelial cell monolayers. East Afr Med J, 1996 Jan, 73(1), 67 - 71 Antibiotic sensitivity pattern of prevalent bacterial pathogens in Gondar, Ethiopia; Aseffa A et al.; The prevalence and sensitivity pattern of common bacterial isolates from clinical specimens processed over one year in the bacteriology laboratory of a teaching hospital in north-west Ethiopia was investigated . Staphylococcus aureus, Escherichia coli and other enteric Gram-negative rods were the predominant pathogens cultured . Klebsiella species were responsible for a nosocomial outbreak among children in the year . The majority of the strains, irrespective of genera, were resistant to tetracycline (> 60%), co-trimoxazole (> 55%) and chloramphenicol (> 45%) . Resistance to ampicillin was seen in > 60% of isolates other than S . aureus . Sensitivity to gentamicin was high (> 89%) among S . aureus, E . coli and Pseudomonas strains . Isolates of Klebsiella, Enterobacter and Proteus were the least sensitive to the aminoglycoside . A multiplicity of antibiograms and predominance of certain multiresistant strains was observed for the prevalent species . Comparison made with reports from elsewhere in Ethiopia indicates that resistance to the commonly available (and cheaper) broad-spectrum antibiotics is a nationwide problem . A suggestion is made to enforce rational drug use before potent antibiotics are introduced under prescriber pressure. Can J Microbiol, 1996 Jan, 42(1), 72 - 5 Levels and identities of nonrhizobial microorganisms found in commercial legume inoculant made with nonsterile peat carrier; Olsen PE et al.; Sixty samples of commercial North American legume inoculants manufactured for sale in 1994 using nonsterile peat as carrier were tested for Rhizobium (or Bradyrhizobium) content and non-Rhizobium biological contaminant load . Products of three major producers of such inoculants for sale in Canada were examined . Viable Rhizobium content varied from 5.6 x 10(5) to 8.1 x 10(9) cells/g, while the contaminant load varied from 1.8 x 10(8) to 5.5 x 10(10) cfu/g . Most of the inoculants contained more nonrhizobial organisms than they did rhizobia . Identifications were made of the most numerous nonrhizobial bacteria occurring in 100 samples of inoculants collected in 1993 and 1994 . The most commonly identified contaminant was Xanthomonas maltophilia . Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacter cloacae were also found at high levels in some products . Contaminant organisms capable of inhibiting rhizobial growth in plate culture were found in the products of all three manufacturers. Int J Syst Bacteriol, 1996 Jan, 46(1), 173 - 82 Phylogeny of the Sphaerotilus-Leptothrix group inferred from morphological comparisons, genomic fingerprinting, and 16S ribosomal DNA sequence analyses; Siering PL et al.; Phase-contrast light microscopy revealed that only one of eight cultivated strains belonging to the Sphaerotilus-Leptothrix group of sheathed bacteria actually produced a sheath in standard growth media . Two Sphaerotilus natans strains produced branched cells, but other morphological characteristics that were used to identify these bacteria were consistent with previously published descriptions . Genomic fingerprints, which were obtained by performing PCR amplification with primers corresponding to enterobacterial repetitive intergenic consensus sequences, were useful for distinguishing between the genera Sphaerotilus and Leptothrix, as well as among individual strains . The complete 16S ribosomal DNA (rDNA) sequences of two strains of "Leptothrix discophora" (strains SP-6 and SS-1) were determined . In addition, partial sequences (approximately 300 nucleotides) of one strain of Leptothrix cholodnii (strain LMG 7171), an unidentified Leptothrix strain (strain NC-1), and four strains of Sphaerotilus natans (strains ATCC 13338T {T = type strain}, ATCC 15291, ATCC 29329, and ATCC 29330) were determined . We found that two of the S . natans strains (ATCC 15291 and ATCC 13338T), which differed in morphology and in their genomic fingerprints, had identical sequences in the 300-nucleotide region sequenced . Both parsimony and distance matrix methods were used to infer the evolutionary relationships of the eight strains in a comparison of the 16S rDNA sequences of these organisms with 16S rDNA sequences obtained from ribosomal sequence databases . All of the strains clustered in the Rubrivivax subdivision of the beta subclass of the Proteobacteria, which confirmed previously published conclusions concerning selected individual strains . Additional analyses revealed that all of the S . natans strains clustered in one closely related group, while the Leptothrix strains clustered in two separate lineages that were approximately equidistant from the S . natans cluster . This finding suggests that the tentative species "L . discophora" needs to be more clearly defined and compared with other species belonging to the genus Leptothrix. Scand J Immunol, 1996 Jan, 43(1), 101 - 8 HLA-B27-restricted cytotoxic T lymphocyte responses to arthritogenic enterobacteria or self-antigens are dominated by closely related TCRBV gene segments . A study in patients with reactive arthritis; Duchmann R et al.; Identification of the T-cell receptors (TCR) used by synovial cytotoxic T lymphocytes (CTL) of patients with reactive arthritis (ReA) may be crucial to better understanding the pathogenetic mechanism underlying the HLA-B27 association of spondylarthropathies . The authors, therefore, sequenced 25 TCRB chains from HLA-B27-restricted CD8+ CTL clones and two clonal lines specific for self- or Yersinia enterocolitica antigen isolated from synovial fluids of 3 HLA-B27+ patients with ReA and PBL of one healthy HLA-B27+ individual . Fourteen non-HLA-B27-restricted CTL served as controls . Both autoreactive and Y . enterocolitica specific HLA-B27-restricted CTL used a highly limited set of VB genes with preferential rearrangement of three closely related VB families (VB 13, 14, 17), suggesting that these families contain a preferred site for contact with the HLA-B27 molecule . In addition, the presence of limited TCRBJ usage, limited heterogeneity in CDR3 sequences and dominant clones from individual donors among these CTL indicate that TCRB chain usage is further restricted by a limited set of peptides bound to the HLA-B27 molecule . Limited TCR usage by SF CTL of ReA patients may lay a basis for therapeutical manipulation of the T-cell response in the spondylarthropathies. Mol Gen Genet, 1995 Dec 20, 249(6), 629 - 36 Regulation of nif gene expression in Enterobacter agglomerans: nucleotide sequence of the nifLA operon and influence of temperature and ammonium on its transcription; Siddavattam D et al.; The nucleotide sequence of a plasmid-borne 3.9 kb XhoI-SmaI fragment comprising the 3'-region of the nifM gene, the nifL and nifA genes and the 5'-region of nifB gene of Enterobacter agglomerans was determined . The genes were identified by their homology to the corresponding nif genes of Klebsiella pneumoniae . A typical sigma 54-dependent promoter and a consensus NtrC-binding motif were identified upstream of nifL . The predicted amino acid sequence of NifL showed close similarities to NifL of K . pneumoniae and Azotobacter vinelandii . However, no histidine residue was found to correspond to histidine-304 of A . vinelandii NifL, which had been proposed to be required for the repressor activity of NifL . The NifA sequence with a putative DNA binding motif (Q(x3) A(x3) G(x5)I) and an ATP binding site in the C-terminal and central domains, respectively, resembles that of other known NifA proteins . The function of the nifL and nifA genes was demonstrated in vivo using a binary plasmid system by their ability to activate a nifH promoter-lacZ fusion at different temperatures and concentrations of NH4+ . Maximal promoter activity occurred at 25 degrees C, and it appears that the sensitivity of NifA to elevated temperatures is independent of NifL . The expression of nifL inhibited promoter activity in the presence of NifA when the initial NH4+ concentration in the medium exceeded 4 mM. Eur J Biochem, 1995 Dec 15, 234(3), 934 - 8 A conserved histidine residue of Escherichia coli outer-membrane phospholipase A is important for activity; Brok RG et al.; Escherichia coli outer-membrane phospholipase A (OMPLA) is thought to be a member of the class of serine hydrolases, having a classical Asp-His-Ser catalytic triad {Horrevoets, A . J . G., Verheij, H . M . & de Haas, G . H . (1991) Eur . J . Biochem . 198, 247-253} . To identify the histidine residue that is important for catalytic activity, the four histidine residues in E . coli OMPLA that are conserved in other enterobacterial OMPLA enzymes were replaced by cysteine residues using PCR-directed, site-specific mutagenesis . The resulting mutant proteins were all well expressed and displayed heat modifiability, indicating that they were properly folded . Enzyme assays showed that only the His142Cys mutant protein was lacking enzymatic activity . In addition, a His142Gly mutant protein appeared to be inactive . These results show that His142 is important for the enzymatic activity of OMPLA. Mol Gen Genet, 1995 Dec 15, 249(5), 526 - 32 Site-specific mutagenesis in Enterobacter agglomerans: construction of nif B mutants and analysis of the gene's structure and function; Siddavattam D et al.; A novel technique was developed which may be generally well suited to the site-specific construction of mutations in Enterobacter agglomerans . The method is based on the observation that E . agglomerans can be cured of a plasmid of the incompatibility group IncQ by cultivation on citrate-containing medium . To test the applicability of this technique, we inserted a kanamycin cassette into the cloned nifB gene, transferred it into E . agglomerans, and selected for recombinants in which the wild-type nifB was replaced by the mutated gene by growing transformants on citrate medium with kanamycin . The nifB- mutants with the kanamycin cassette inserted in either orientation showed a nif- phenotype . Further, we determined the nucleotide sequence of nifB . A typical sigma 54-dependent promoter and a consensus NifA binding site were found upstream of nifB . Activation of this promoter by both heterologous and homologous NifA proteins was observed in vivo . The predicted amino acid sequence of the NifB protein showed strong similarity to the NifB sequences of other diazotrophic bacteria . The typical clustering of cysteine residues at the N-terminal end indicates its involvement in Fe-Mo cofactor biosynthesis. J Hosp Infect, 1995 Dec, 31(4), 305 - 17 Changing patterns of susceptibilities of blood, urinary and respiratory pathogens in Hong Kong; Ho P et al.; The incidence and antimicrobial susceptibility of organisms isolated from blood, urine and respiratory specimens at a teaching hospital in Hong Kong were studied retrospectively from 1986-1993 . The incidence of Gram-positive bacteraemia, particularly coagulase-negative staphylococci (CNS), increased significantly from 33.6 to 47.3% (P < 0.001) while that of Gram-negative bacteraemia fell from 60.0 to 47.0% (P < 0.001) . Among blood isolates, methicillin resistance of CNS increased from 17.0 to 58.0% (P < 0.001) and cefuroxime resistance of Enterobacter spp . increased from 21.0 to over 50% (P < 0.01) . Among urinary isolates, cefuroxime resistance of Klebsiella spp . (11.0 to 24.0%, P < 0.001) and Enterobacter spp . (32.0 to 75.0%, P < 0.001) increased . Nalidixic acid resistance among Gram-negative urinary isolates, except Proteus mirabilis, rose by three- to sixfold . For Streptococcus pneumoniae, isolated from the respiratory tract, penicillin resistance increased dramatically (2 to 18%, P < 0.001) . For respiratory isolates of Haemophilus influenzae, ampicillin resistance increased from 17.0 to 29.0% (P < 0.001) . These data are useful in guiding empirical treatment of nosocomial infections. Poult Sci, 1995 Dec, 74(12), 1948 - 60 Utilization of fermented flocculated poultry sludge as a feed constituent for pigs; Fransen NG et al.; Flocculated poultry sludge was mixed with 3% molasses and was flow-therm pasteurized for 5 min at a core temperature of 95 C . The sludge was subsequently cooled to between 20 and 25 C and fermented with Lactobacillus plantarum as starter culture . Three groups of eight 8- to 10-wk-old, individually housed fattening pigs (Hypor) were fed according to a fixed scheme correlated with age . One control group received a restricted ration of commercial compound feed (Group A) . The other control group was provided "nearly ad libitum" access to the same commercial compound feed (Group C) . The experimental group received the same amount of commercial compound feed as Group A, but the diet was supplemented with fermented sludge, at an inclusion rate of 19 to 28% of the total ration (DM basis) . The pigs fed the sludge-containing diet and those receiving the compound pig feed "nearly ad libitum" showed comparable growth results . It was concluded that the net energy (NEpig) level of .68 g DM of sludge was comparable to the NEpig level of 1 g compound pig feed (88% DM) . A decrease in colony counts of Enterobacteriaceae in the intestinal tract of the pigs, was regarded as positive, as it might lower the risk of disturbance of the gut flora by enteropathogenic bacteria such as Escherichia coli and Salmonella . No adverse effects on health and performance were observed as a result of the feeding of pasteurized and subsequently fermented flocculated poultry sludge to fattening pigs . It is concluded that this sludge can serve as a valuable feed constituent as long as it is processed properly. J Antimicrob Chemother, 1995 Dec, 36(6), 975 - 85 In-vivo transfer of resistance plasmids in rat, human or pig-derived intestinal flora using a rat model; Nijsten R et al.; Germ-free rats associated with either rat- (RIF), human- (HIF) or pig-(PIF) derived Enterobacteriaceae-free intestinal flora were used for in vivo experiments to detect transfer of antibiotic resistance . Transfer of resistance was observed most frequently from the porcine donor strain to acceptor strain Escherichia coli K12, showing the highest number of transconjugants in the faeces of HIF-rats . The rats associated with the human donor strain and E . coli K12 as acceptor showed transconjugants less frequently . Only the HIF-rats yielded transconjugants on each sampling day and none at all could be isolated from the PIF-rats . Almost no transconjugants were found in the faeces of rats associated with the pig donor strain and a wild human E . coli strain as acceptor . Factors such as the nature of the donor and recipient strains as well as the origin of the intestinal flora seemed to have an influence on plasmid transfer . Transferability was highest in the HIF-rats and could be increased by administration of lincomycin . This study showed that in vivo transfer of resistance plasmids is possible in rats associated with intestinal floras of different origins . The human intestinal flora seemed to permit better transfer of resistance than that derived from the pig or the rat. Hybridoma, 1995 Dec, 14(6), 557 - 62 Monoclonal antibodies directed against unique and common determinants on the lipopolysaccharide molecule of Salmonella serogroups A, B, and D; Merkulova TI et al.; A panel of monoclonal antibodies (MAbs) directed against lipopolysaccharide (LPS) of Salmonella serogroups A, B, and D was generated . Nine most productive hybrid clones were selected from several fusions of mouse myeloma cells with splenocytes from BALB/c mice, immunized with the corresponding heat-killed bacteria . The MAbs were characterized by enzyme immunoassay, Western blot analysis, and dot-immunoblotting with LPS and whole bacteria of Salmonella serogroups A-E and some other representatives of the Enterobacteriaceae family . Seven MAbs were reactive with the sole Salmonella strain used as an immunogen; one MAb, SD:10D9H, reacted with the five major serogroups of Salmonella species (A, B, D, E1, and E2); and one MAb, SA:5D12A, reacted with Salmonella serogroups A-E and a rough strain of S . cholerae-suis . None of the MAbs reacted with LPS of E . coli 055:B5 or whole bacteria of E . coli K12, Klebsiella pneumoniae, or Proteus vulgaris . The typical ladder-like patterns of bands were observed after immunoblotting of MAbs against electrophoretically resolved LPS from Salmonella serogroups A-E, which thus confirmed their LPS-directed specificity . MAbs affinity constants were determined by noncompetitive enzyme immunoassay using serial dilutions of both LPS as antigen (coating the plate) and antibodies . On the base of the results obtained, the presumed epitopes for each of the MAbs were discussed . The usefulness of MAbs generated for diagnostic and protective purposes was declared. FEMS Immunol Med Microbiol, 1995 Dec, 12(3-4), 213 - 16 The production of neuraminidase and fucosidase by Helicobacter pylori: their possible relationship to pathogenicity; Dwarakanath AD et al.; The pathogenicity of enterobacteria often correlates with their production of neuraminidase (sialidase) . Forty-nine Helicobacter pylori isolates have therefore been examined for their production of neuraminidase and other glycosidases . All 49 isolates produced considerable neuraminidase (median 228 IU/microg protein, interquartile range 121-370), pH optimum 7.5 . Nine of the 49 also produced fucosidase (median 23 IU/microg protein, interquartile range 12-39), pH optimum 7.0 . Production of these enzymes did not correlate with bacterial Cag A expression or duodenal ulceration . Neutrophils exposed to neuraminidase show increased adherence to endothelium so the neuraminidase production by H . pylori could partly explain the predominant neutrophil inflammatory infiltrate seen in H . pylori-associated gastritis . Inhibition of this enzyme by use of neuraminidase-inhibitors could be a useful therapeutic approach. J Dairy Sci, 1995 Dec, 78(12), 2745 - 52 Antigenic crossreactivity and lipopolysaccharide neutralization properties of bovine immunoglobulin G; Tomita GM et al.; We investigated a possible mechanism by which immunization against core and lipid A determinants of lipopolysaccharide reduced clinical cases of mastitis and symptoms commonly associated with heterologous Gram-negative IMI . The IgG fraction of sera from cows immunized with either Escherichia coli J5 bacterin, E . coli J5 lipopolysaccharide conjugate vaccine, or unimmunized controls was purified by precipitation with caprylic acid and ammonium sulfate . The degree of IgG crossreactivity with Gram-negative bacteria that were isolated from clinical quarters was greater than that with Gram-positive isolates of Staphylococcus aureus . The highest magnitude of crossreactivity was against smooth strain E . coli isolates, followed by heterologous species of Enterobacter, Serratia, and Klebsiella isolates . Serum IgG from cows immunized with conjugate was highly crossreactive to E . coli J5, E . coli O111:B4, Serratia marcescens, Klebsiella pneumoniae, and Salmonella typhimurium lipopolysaccharides . The magnitude of antibody crossreactivity with lipopolysaccharides coincided with the ability of IgG to suppress the mitogenic effect of lipopolysaccharides on bovine lymphocytes. Jpn J Antibiot, 1995 Dec, 48(12), 1899 - 905 {Antimicrobial activities of clavulanic acid/ticarcillin against clinical isolates}; Koguchi M et al.; In order to investigate antimicrobial activities of clavulanic acid/ticarcillin (CVA/TIPC) against Escherichia coli, Enterobacter spp . and Pseudomonas aeruginosa in 1992 and 1994, beta-lactamase activities were analyzed and minimum inhibitory concentrations (MICs) were determined including those of the control drugs . The results are as follows; 1 . Compared to a report in 1980, the MIC distributions of CVA/TIPC against E . coli and P . aeruginosa did not show large differences . We found, however, that CVA/TIPC-resistant strains increased among Enterobacter spp . 2 . Almost all of CVA/TIPC-resistant strains of Enterobacter spp . were also resistant to cephems and new quinolones, thus they were multiple drug resistant . 3 . CVA/TIPC showed strong antimicrobial activities against penicillinase producing E . coli. Kansenshogaku Zasshi, 1995 Dec, 69(12), 1329 - 35 {Survey bacterial isolates from blood samples during 1987-1993 in our department}; Takagi T et al.; We analyzed the changes in frequency of bacterial isolates from the blood samples in our department from May 1987 to December 1993 . 565 isolates from 4887 samples (11.6%) were detected . Among the detected microorganisms, the rate of gram-positivecocci (GPC) was much higher than the other kinds of the isolates each year . Especially, 80-90% of GPC were occupied by only 2 kinds of microorganisms, coagulase negative Staphylococci (CNS) and S . aureus . Among gram-negative-rods (GNR), constant increase of S . marcescens and transient increase of Enterobacter and P . aeruginosa were recognized . In 30 cases (5.3%), 2-3 kinds of microorganisms were isolated concomitantly, and in 55 cases (9.7%), the microorganisms, which was mainly caused by CNS, S . aureus and Candida, was isolated from both blood samples and the tip of the IVH catheter concomitantly . 42.5% of the bacterial positive cases in 1933 underwent 2 more kinds of the indwelling catheters and 48.3% were administrated antibiotics . Most of the cases had underlying diseases including mainly malignant tumor (leukemia, solid tumor), cerebrovascular diseases, and multiple injuries. Lett Appl Microbiol, 1995 Dec, 21(6), 398 - 401 Ascorbate as an induction inhibitor of beta-lactamase in a strain of Enterobacter cloacae; Shoeb HA et al.; The effect of ascorbate and anaerobiosis of beta-lactamase content (constitutive and inducible) in relation to the susceptibility of a standard strain of Enterobacter cloacae to ampicillin was studied . Enterobacter cloacae ATCC 13047 showed increasing susceptibility to ampicillin when incubated anaerobically in the presence of increasing concentrations of ascorbic acid . The inducible beta-lactamase activity in the cell-free extracts of Ent . cloacae decreased when the bacterium was grown aerobically in the presence of ascorbic acid . Under anaerobic growth conditions, however, ascorbic acid abrogated the induction of the enzyme completely . On the other hand, the constitutive enzymatic activity was markedly decreased as the bacterium was grown anaerobically . Thus under these growth conditions ascorbate-anaerobiosis, the total beta-lactamase level in the presence of ampicillin as inducer fell below the basal constitutive activity observed in the absence of ampicillin. Crit Care Nurs Clin North Am, 1995 Dec, 7(4), 667 - 74 Antibiotic prophylaxis in the critical care setting; Goldman MP; The prevention of infection in critically ill patients is a difficult and often frustrating task . Selective digestive decontamination may be a useful means of preventing infections in specific patient populations; however, not all critical care patients will benefit . In this article, mechanisms of antimicrobial resistance are discussed along with the consideration of specific measures to deal with this growing dilemma . Concerns about specific microorganisms, such as vancomycin-resistant enterococcus and multidrug-resistant Enterobacter species, are addressed . It is clear that the use of antimicrobial agents is not the only solution to the problem of infection in critically ill patients. Arch Dis Child, 1995 Dec, 73(6), 549 - 51 Effects of nicotine on bacterial toxins associated with cot death; Sayers NM et al.; Toxins produced by staphylococci and enterobacteria isolated from the nasopharynx of cases of sudden infant death syndrome (SIDS) have a lethal effect when injected into chick embryos . If the toxins are progressively diluted the lethal effect disappears, but certain combinations of toxins show synergy so that if sublethal doses are mixed a highly lethal effect is produced . In this paper it is shown that nicotine at very low concentrations (less than that produced in man by 0.05 cigarettes) potentiates the lethal action of certain SIDS associated bacterial toxins and markedly potentiates the lethal action of synergistic combinations of bacterial toxins . These results could explain, at least in part, why parental smoking increases the risk of SIDS . They also provide further support for the common bacterial toxin hypothesis of cot death. J Bacteriol, 1995 Dec, 177(24), 7245 - 54 Evidence suggesting cis action by the TnaC leader peptide in regulating transcription attenuation in the tryptophanase operon of Escherichia coli; Gish K et al.; Expression of the tryptophanase (tna) operon in Escherichia coli is regulated by catabolite repression and transcription attenuation . Elevated levels of tryptophan induce transcription antitermination at one or more Rho factor-dependent termination sites in the leader region of the operon . Induction requires translation of a 24-residue coding region, tnaC, located in the 319-nucleotide transcribed leader region preceding tnaA, the structural gene for tryptophanase . In the present paper, we show that two bacterial species that lack tryptophanase activity, Enterobacter aerogenes and Salmonella typhimurium, allow tryptophanase induction and tna operon regulation when they carry a plasmid containing the E . coli tna operon . The role of tnaC in induction was examined by introducing mutations in a 24-nucleotide segment of tnaC of E . coli surrounding and including the crucial Trp codon 12 . Some mutations resulted in a noninducible phenotype; these mostly introduced nonconservative amino acid substitutions in TnaC . Other mutations had little or no effect; these generally were in third positions of codons or introduced conservative amino acid replacements . A tryptophan-inserting, UGA-reading glutamine suppressor tRNA was observed to restore partial regulation when Trp codon 12 of tnaC was changed to UGA . Stop codons introduced downstream of Trp codon 12 in all three reading frames established that induction requires translation in the natural tnaC reading frame . Our findings suggest that the TnaC leader peptide acts in cis to prevent Rho-dependent termination. J Bacteriol, 1995 Dec, 177(24), 7011 - 8 A system to generate chromosomal mutations in Lactococcus lactis which allows fast analysis of targeted genes; Law J et al.; A system for generating chromosomal insertions in lactococci is described . It is based on the conditional replication of lactococcal pWV01-derived Ori+ RepA- vector pORI19, containing lacZ alpha and the multiple cloning site of pUC19 . Chromosomal AluI fragments of Lactococcus lactis were cloned in pORI19 in RepA+ helper strain Escherichia coli EC101 . The frequency of Campbell-type recombinants, following introduction of this plasmid bank into L . lactis (RepA-), was increased by combining the system with temperature-sensitive pWV01 derivative pVE6007 . Transformation of L . lactis MG1363 (pVE6007) with the pORI19 bank of lactococcal chromosomal fragments at the permissive temperature allowed replication of several copies of a recombinant plasmid from the bank within a cell because of the provision in trans of RepA-Ts from pVE6007 . A temperature shift to 37 degrees C resulted in loss of pVE6007 and integration of the pORI19 derivatives at high frequencies . A bank of lactococcal mutants was made in this way and successfully screened for the presence of two mutations: one in the monocistronic 1.3-kb peptidoglycan hydrolase gene (acmA) and one in the hitherto uncharacterized maltose fermentation pathway . Reintroduction of pVE6007 into the Mal- mutant at 30 degrees C resulted in excision of the integrated plasmid and restoration of the ability of ferment maltose . The integration plasmid (pMAL) was rescued by using the isolated plasmid content of a restored Mal+ colony to transform E . coli EC101 . Nucleotide sequencing of the 564-bp chromosomal fragment in pMAL revealed an internal part of an open reading frame of which the translated product showed significant homology with ATP-binding proteins MalK of E . coli, Salmonella typhimurium, and Enterobacter aerogenes and MsmK of Streptococcus mutans . This combined use of two types of conditional replicating pWV01-derived vectors represents a novel, powerful tool for chromosomal gene inactivation, targeting, cloning, and sequencing of the labelled gene. Am J Respir Crit Care Med, 1995 Dec, 152(6 Pt 1), 1825 - 34 The role of intragastric acidity and stress ulcus prophylaxis on colonization and infection in mechanically ventilated ICU patients . A stratified, randomized, double-blind study of sucralfate versus antacids; Bonten MJ et al.; This study evaluates the effects of sucralfate and antacids on intragastric acidity, colonization of stomach, oropharynx and trachea, and the incidence of ventilator-associated pneumonia (VAP) in mechanically ventilated patients in intensive care units . We conducted a prospective randomized double-blind trial in which patients were stratified on initial gastric pH . Intragastric acidity was measured with computerized, continuous intragastric monitoring . The diagnosis of VAP was established with protected specimen brush and/or bronchoalveolar lavage . The study included consecutive eligible patients with mechanical ventilation and nasogastric tube . Interventions: After stratification on initial intragastric pH into two groups, patients from both groups were randomly assigned to receive either antacids (a suspension of aluminum hydroxide and magnesium hydroxide), 30 mL every 4 h, or sucralfate, 1 g every 4 h . Continuous intragastric pH monitoring was performed in 112 patients (58 antacids, 54 sucralfate) . Using predetermined criteria, colonization of stomach, oropharynx, and trachea, and the incidence of VAP were assessed . Altogether, 141 patients were included (74 receiving antacids, 67 sucralfate) and continuous intragastric pH monitoring was performed in 112 patients, with a mean of 75 h per patient . The median pH and the percentage of time with a pH < 4.0 were calculated from each measurement . No significant differences in median pH values (4.7 +/- 2.2 and 4.5 +/- 2.0 for antacids and sucralfate, respectively) were observed . Median pH values were higher in patients with gastric bacterial colonization than in noncolonized patients (5.5 +/- 2.1 and 3.3 +/- 2.0, p < 0.01), but colonization of oropharynx and trachea was not related to intragastric acidity . Thirty-one patients (22%) developed VAP, with a similar incidence in both treatment groups . In addition, antibiotic use, duration of hospitalization, and mortality rates were similar in both groups . Enteral feeding did not change intragastric acidity significantly but increased gastric colonization with Enterobacteriaceae, without influencing oropharyngeal and tracheal colonization . Antacids and sucralfate had a similar effect on intragastric acidity, colonization rates, and incidence of VAP . Intragastric acidity influenced gastric colonization but not colonization of the upper respiratory tract or the incidence of VAP . Therefore, it is unlikely that the gastropulmonary route is important for the development of VAP. Plasmid, 1995 Nov, 34(3), 223 - 8 Self-transmissible nif plasmid (pEA9) of Enterobacter agglomerans 339: molecular cloning and evidence for the existence of similar nif clusters on dissimilar plasmids in Enterobacter strains; Steibl HD et al.; A cosmid library was generated to the 200-kb self-transmissible nif plasmid pEA9 isolated from Enterobacter agglomerans 339 . The cosmid clone identified to contain the complete nif cluster was used to determine the nif gene organization and the physical map . The restriction pattern and nif gene organization of this nif cluster showed remarkable similarities to the nif cluster identified on the 110-kb plasmid pEA3 of Enterobacter agglomerans 333 . Nucleotide sequence of several randomly selected regions of the nif cluster of pEA9 showed 96% similarity when compared to the known sequences of the nif cluster of pEA3 . However, the homology ended abruptly at the flanking regions of the nif clusters and no similarity could be detected with the rest of the DNA of these plasmids . This reveals the existence of similar nif clusters on dissimilar plasmids, implying the horizontal transfer of the entire nif gene cluster. Zhonghua Nei Ke Za Zhi, 1995 Nov, 34(11), 764 - 6 {A randomized control study on the treatment of 123 cases of bacterial infections with cefteram and cefaclor}; Li G et al.; To evaluate the efficacy and the safety of cefteram in bacterial infections, a randomized control study of cefteram and cefaclor on the treatment of 123 patients with respiratory and urinary tract infections was carried out . The result showed that the effective and bacterial eradication rates were 92.1% and 91.4% for cefteram . 83.3% and 85.2% for cefalor . Adverse reactions were mainly gastrointestinal reactions, occurring in 4.6% of the cefteram group and 9.4% of the cefaclor group . Study of minimum inhibitory concentration displayed high antibacterial activity of cefteram for enterobacteriaceae and other Gram-negative organisms and its activity was higher than that of gentamyicin and ciprofloxacin for E . coli . It is concluded that cefteram was effective and safe in the treatment of respiratory and urinary tract infections. J AOAC Int, 1995 Nov-Dec, 78(6), 1531 - 7 Detection of Salmonella spp . in eggs: DNA analyses, culture techniques, and serology; Burkhalter PW et al.; A polymerase chain reaction (PCR) method for direct detection of Salmonella spp . in whole-shell eggs is described . The method does not require isolating strains . Preenrichment, rapid DNA isolation, and a nested PCR system targeting the invA gene enabled detection of the genus Salmonella . The specific nested PCR product of 283 base pairs was formed from all 21 serovars, including 43 Salmonella strains tested . No PCR product was formed from 56 non-Salmonella enterobacteriacea and other bacterial strains tested . Experiments with artificially contaminated eggs showed a detection limit of about 10(3)-10(4) colony-forming units (cfu)/egg before and about 1-10 cfu/egg after preenrichment . In analysis of 180 single eggs from 4 flocks and 36 pools of 5 eggs each from another 4 flocks from the same producer, Salmonella spp . were detected in 5 of 90 eggs from 2 different flocks . Determination of anti-Salmonella antibodies in eggs yielded positive results for 2 additional and the 2 PCR-positive flocks . In contrast, classical selective culture detected Salmonella spp . in only 1 of 100 eggs in one flock when 100 eggs from each flock were analyzed. Infection, 1995 Nov-Dec, 23(6), 384 - 7 In vitro activity of cefpirome against selected clinical enterobacterial isolates with beta-lactamase-mediated resistance; Tzouvelekis LS et al.; Previous studies have shown that there is a high incidence of resistance to cephalosporins among enterobacteria isolated in Greek hospitals . This resistance is mainly due to either the derepression of chromosomal cephalosporinases or the acquisition of plasmids coding for SHV-5 type beta-lactamase . In the present study the activity of cefpirome against a number of enterobacteria (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Enterobacter aerogenes and Serratia marcescens) possessing the mechanisms mentioned above was examined . Cefpirome was found active against all the strains characterized by stable derepression of chromosomal class-C enzymes . The antibiotic was less potent against strains expressing SHV-5 type beta-lactamase due to its hydrolysis by the enzyme . Also cefpirome exhibited good activity against E . aerogenes strains with reduced susceptibility to imipenem . These in vitro data suggest that cefpirome might be useful in treating infections caused by these resistant microorganisms that are frequently encountered in Greek hospitals. Infection, 1995 Nov-Dec, 23(6), 339 - 43 Biochemical profiles and serotypes of nosocomial Enterobacter cloacae strains in Northern Norway: biochemical identification problems with commercial test systems; Andersen BM; During a period of 2 years, 118 strains of Enterobacter cloacae were collected consecutively in connection with nosocomial infections in Northern Norway; identified by conventional methods and by the API 20E system . The API 20E profile 3305573 predominated and was present in 73 of 118 strains . Among 96 serotyped strains, 73 were serotypable, 20 nontypable and two polyagglutinable . Predominating serotypes were 3 (29 strains), 8 (21 strains) and 23 (nine strains) . When the API 20E profiles of the 118 strains were read in the new ATB (automated computer-assisted) 20E data base system, 97 of 118 (82.2%) strains were identified as E . cloacae . The 118 strains were tested in the new ATB Rapid ID 32E and ATB ID 32E (ATB system, bioMerieux, France) systems . Only 69 of 118 (58.5%) strains were identified as E . cloacae in both systems . The ATB Rapid ID 32E identified 97 of 118 strains (82.2%), and the ATB ID 32E only 80 of 118 strains (67.8%) . Among 73 serotypable strains, the ATB Rapid ID 32E identified 79.5% as E . cloacae, while the ATB ID 32E identified only 64.4% . Among 40 serotypable strains with API 20E profile 3305573, all 40 were identified as E . cloacae by the ATB Rapid ID 32E, while only 27 (67.5%) by the ATB ID 32E system . Further improvements may increase the value of biochemical identification of E . cloacae in diagnostic work. J Antimicrob Chemother, 1995 Nov, 36(5), 757 - 71 Laboratory assessment of antibacterial activity of zwitterionic 7-methoxyimino cephalosporins; Pechere JC et al.; Zwitterionic 7-methoxyimino cephalosporins (cefpirome, cefepime, cefclidin, DQ2556, FK037 and SCE2787) possess a variable substitution at C3 which contains a quarternary nitrogen . These cephalosporins display low affinities for Class I beta-lactamase and rapid penetration through the outer membrane of Gram-negative bacilli, so that an increased number of periplasmic beta-lactam molecules interact with PBP's per unit of time . As a consequence, the new zitterionic compounds remain active against some, but not all, ceftazidime-resistant Enterobacteriaceae producing high levels of Class I beta-lactamase or Bush type 2b beta-lactamases . Antipseudomonas activities are generally similar to that of ceftazidime except that cefclidin is more active . The new zwitterionic compounds, especially cefpirome and FK037, express greater antistaphylococcal potency than does ceftazidime . A variety of animal models including meningitis and endocarditis have confirmed the potential of these compounds in-vivo . On the basis of structural and antibacterial characteristics, the expression 'forth generation' is acceptable to describe the zwitterionic 7-methoxyimino cephalosporins. Br Vet J, 1995 Nov-Dec, 151(6), 643 - 58 Salmonella fimbriae: novel antigens in the detection and control of salmonella infections; Thorns CJ; Fimbriae are thin, proteinaceous surface organelles produced by members of the Enterobacteriaceae, including most salmonellas . A number of fimbrial antigens expressed by strains of Salmonella enteritidis and S . typhimurium have now been described and characterized . However, their functions are still poorly understood, although some evidence indicates they have a role in bacterial survival in the host or external environment . Diagnostic tests based on the detection of fimbriae or specific antibodies against them have recently been developed and applied successfully to the rapid and specific identification of S . enteritidis infections . The role of salmonella fimbriae in future generations of live vaccines either as protective antigens or as the carriers of heterologous antigens is also discussed. Antimicrob Agents Chemother, 1995 Nov, 39(11), 2580 - 2 First characterization of inhibitor-resistant TEM (IRT) beta-lactamases in Klebsiella pneumoniae strains; Lemozy J et al.; Two clinical strains of Klebsiella pneumoniae, TP 01 and TP 02, presented resistance to amoxicillin-clavulanate and were fully susceptible to cephalothin . These strains produced two beta-lactamases, SHV-1 and a TEM enzyme with a pI of 5.2 . The previously described changes Arg-244-->Cys and Arg-244-->Ser in IRT-1 and IRT-2 (A . Belaaouaj, C . Lapoumeroulie, M . M . Canica, G . Vedel, P . Nevot, R . Krishnamoorthy, and G . Paul, FEMS Microbiol . Lett . 120:75-80, 1994) were found in TEM enzymes from the TP 01 and TP 02 strains, respectively . This is the first report of inhibitor-resistant TEM (IRT) in species other than Escherichia coli from the family Enterobacteriaceae. J Clin Microbiol, 1995 Nov, 33(11), 2856 - 8 Controlled clinical evaluation of BACTEC Plus Aerobic/F and BacT/Alert Aerobic FAN bottles for detection of bloodstream infections; Pohlman JK et al.; A total of 7,190 blood culture sets were obtained from adult patients with a suspected bloodstream infection . A 20-ml sample of blood was distributed equally between the aerobic FAN bottle which was monitored in the BacT/Alert system and a Plus Aerobic/F bottle which was monitored in the BACTEC 9240 system . A total of 988 positive cultures were obtained from 483 patients; however, only 453 positive cultures from 173 patients met the criteria for volume ( > or = ml per bottle) and clinical significance on the basis of concurrent case review required for data analysis . There were 25 and 68 false positives from the FAN and Plus Aerobic/F bottles, respectively . There were no statistically significant differences between systems in the number of positive cultures or septic episodes by species; however, the total number of Enterobacteriaceae and Pseudomonas aeruginosa isolates combined was significantly greater in the FAN bottle (P = 0.04) . Detection times did not differ significantly between systems for positive cultures; however, episodes of Staphylococcus aureus bacteremia were detected significantly more rapidly from the FAN bottle (P = 0.005) . There was no significant difference between systems in the detection of bloodstream infections in patients receiving antibiotics at the time of blood culture. Chemotherapy, 1995 Nov-Dec, 41(6), 477 - 86 A multicenter comparative study of the in vitro activity of fleroxacin and other antimicrobial agents; Markowitz SM et al.; The in vitro activity of fleroxacin was determined by broth microdilution against 2,079 recent bacterial isolates and compared to the activities of ciprofloxacin, ofloxacin, lomefloxacin, cefaclor, cefuroxime, cefixime, ceftriaxone, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole (TMP-SMX), and, as appropriate, erythromycin and oxacillin . Most Enterobacteriaceae were inhibited by the quinolones at a concentration of < or = 1 microgram/ml; MIC90s of fleroxacin, ciprofloxacin, ofloxacin, and lomefloxacin were 0.25, 0.5, 1 and 1 micrograms/ml, respectively . Fleroxacin was 2-fold more active than ciprofloxacin against Providencia stuartii and Serratia marcescens . Aside from the quinolones, ceftriaxone and TMP-SMX were the most active antibiotics against the Enterobacteriaceae, with MIC90s of 8 and 16 micrograms/ml, respectively . Ciprofloxacin was more active against Pseudomonas aeruginosa than the other quinolones, while fleroxacin was more active against Stenotrophomonas maltophilia: 17.7, 11.2, 20.0, and 22.4% of P . aeruginosa were resistant to fleroxacin, ciprofloxacin, ofloxacin, and lomefloxacin, respectively . Moraxella catarrhalis and Haemophilus influenzae were uniformally susceptible to all antibiotics tested, as were the majority of oxacillin-susceptible staphylococci . The MIC90s of the quinolones and of the beta-lactam antibiotics for oxacillin-resistant staphylococci were 8- to 256-fold higher than for oxacillin-susceptible staphylococci . The beta-lactam antibiotics, TMP-SMX, and erythromycin were more active than the quinolones against streptococci; all antibiotics were poorly active against enterococci . Fleroxacin is active against a broad range of gram-negative bacilli and against oxacillin-susceptible staphylococci and should prove useful for such infections . However, its use cannot be recommended for infections due to oxacillin-resistant staphylococci, streptococci, or enterococci. Appl Environ Microbiol, 1995 Nov, 61(11), 4131 - 4 Orally administered bovine lactoferrin inhibits bacterial translocation in mice fed bovine milk; Teraguchi S et al.; Feeding of bovine milk to mice induced a high incidence of bacterial translocation from the intestines to the mesenteric lymph nodes, and the bacteria involved were mainly members of the family Enterobacteriaceae . Supplementation of the milk diet with bovine lactoferrin or a pepsin-generated hydrolysate of bovine lactoferrin resulted in significant suppression of bacterial translocation . Our findings suggest that this ability of lactoferrin to inhibit bacterial translocation may be due to its suppression of bacterial overgrowth in the guts of milk-fed mice. J Bacteriol, 1995 Nov, 177(22), 6411 - 21 Molecular cloning, mapping, and regulation of Pho regulon genes for phosphonate breakdown by the phosphonatase pathway of Salmonella typhimurium LT2; Jiang W et al.; Two pathways exist for cleavage of the carbon-phosphorus (C-P) bond of phosphonates, the C-P lyase and the phosphonatase pathways . It was previously demonstrated that Escherichia coli carries genes (named phn) only for the C-P lyase pathway and that Enterobacter aerogenes carries genes for both pathways (K.-S . Lee, W . W . Metcalf, and B . L . Wanner, J . Bacteriol . 174:2501-2510, 1992) . In contrast, here it is shown that Salmonella typhimurium LT2 carries genes only for the phosphonatase pathway . Genes for the S . typhimurium phosphonatase pathway were cloned by complementation of E . coli delta phn mutants . Genes for these pathways were proven not to be homologous and to lie in different chromosomal regions . The S . typhimurium phn locus lies near 10 min; the E . coli phn locus lies near 93 min . The S . typhimurium phn gene cluster is about 7.2 kb in length and, on the basis of gene fusion analysis, appears to consist of two (or more) genes or operons that are divergently transcribed . Like that of the E . coli phn locus, the expression of the S . typhimurium phn locus is activated under conditions of Pi limitation and is subject to Pho regulon control . This was shown both by complementation of the appropriate E . coli mutants and by the construction of S . typhimurium mutants with lesions in the phoB and pst loci, which are required for activation and inhibition of Pho regulon gene expression, respectively . Complementation studies indicate that the S . typhimurium phn locus probably includes genes both for phosphonate transport and for catalysis of C-P bond cleavage. Curr Microbiol, 1995 Nov, 31(5), 287 - 90 Isolation of Ewingella americana from mollusks; Muller HE et al.; Twenty-three of 2446 strains of Enterobacteriaceae isolated from mollusks were identified as Ewingella americana both biochemically and by DNA hybridization with strain S6/1111 . The biochemical characteristics of the new strains showed few differences from previously reported strains obtained from human clinical specimens . These are the first strains of E . americana isolated from animals. FEMS Microbiol Lett, 1995 Oct 15, 132(3), 259 - 62 Membrane hyperpolarisation by valinomycin and its limitations for bacterial viability assessment using rhodamine 123 and flow cytometry; Porter J et al.; The ionophore, valinomycin, was investigated as a possible means of bacterial viability assessment using the fluorescent membrane potential dye rhodamine 123 . Membrane hyperpolarisation in Escherichia coli, Pseudomonas fluorescens, Enterobacter aerogenes and Arthrobacter globiformis was examined during exponential growth and during stress by brief starvation in a high sodium, low potassium buffer using flow cytometric analysis of rhodamine 123 uptake . Dye uptake was variable both between species and amongst cells from the same culture . Exponential phase cells showed no increase in dye uptake due to valinomycin treatment . Stressed P . fluorescens cells responded to valinomycin treatment by increased dye uptake, while stressed E . coli and A . globiformis cells showed no response . Approximately 50% of stressed Eb . aerogenes cells responded to valinomycin . The results demonstrate the limitations of rhodamine dye for viability analysing the viability of diverse bacterial communities and underline the degree of cell heterogeneity in batch cultures. Biochim Biophys Acta, 1995 Oct 5, 1258(3), 225 - 7 Occurrence of a furan fatty acid in marine bacteria; Shirasaka N et al.; A fatty acid containing a furan ring was detected in the cellular lipids of marine bacteria, Shewanella putrefaciens, Marinomonas comunis, Enterobacter agglomerans, Pseudomonas fluorescens, etc., which were isolated from the intestinal liquor of fishes . Analytical data indicated that the fatty acid was 10,13-epoxy-11-methyloctadeca-10, 12-dienoic acid . Therefore, we propose that furan fatty acids detected in marine fish are derived not only from marine plants but also from intestinal bacteria of fishes. Microb Drug Resist, 1995 Fall, 1(3), 195 - 202 Molecular epidemiology of integron-associated antibiotic resistance genes in clinical isolates of enterobacteriaceae; Sallen B et al.; The epidemiology of integron-mediated antibiotic-resistant genes in clinical enterobacteria from a single location was investigated . Forty-nine isolates (kindly provided by Dr . D . Sirot, Clermont-Ferrand, France) were selected for transferable resistance to aminoglycosides or to other antibiotics . Total DNA prepared from these strains was screened for the presence of conserved segments of integrons by PCR . The nature and frequency of inserted resistance gene cassettes were determined by direct nucleotide sequencing and were related to the resistances expressed by the strain . Integron hot-spots were present in 59% of the strains from 6 species, in either one or two copies . For amplicons sequenced, one or two antibiotic-resistant genes were found in various combinations, and were always expressed at the phenotypic level . They included the aminoglycoside resistance genes ant(3")-Ia and aac(6')-Ib (75%), as well as dhfr-I,-VII (21.4%) and blaOXA-1 (3.6%) . Almost half of the transferable resistance to aminoglycosides (53%) was mediated by integron hot-spots in strains characterized at the nucleotide level . The proportion rose to 100% for the AAC(6')-I resistance profile . This study emphasizes the important contribution of integrons to aminoglycoside resistance within enterobacteria from a clinical setting. Plant Foods Hum Nutr, 1995 Oct, 48(3), 185 - 92 Studies on samh seeds (Mesembryanthemum forsskalei Hochst) growing in Saudi Arabia: 2: Chemical composition and microflora of samh seeds; Al-Jassir MS et al.; The chemical composition of samh seeds have been investigated . Proximate analysis showed a composition of 22.25% protein, 5.7% moisture, 5.6% fat, 4.0% ash, 9.7% crude fiber, and the remainder being total carbohydrates . Mineral element analysis revealed that potassium, magnesium, sodium and calcium were present as the major elements . Iron, manganese, zinc and copper were found at lower levels . However, lead was not detected in the samh seeds . Gas-liquid chromatographic analysis of the methylester of the fatty acids of the samh seeds oil revealed the presence of fourteen fatty acids . Linoleic and oleic acids were the principle unsaturated fatty acids . While palmitic acid was the main saturated fatty acid . Amino acid analysis of the samh seeds showed the presence of seventeen amino acids including eight essential amino acids . Glutamic acid, arginine, and aspartic acid were the major amino acids . Cystine and proline were present in trace amounts . These results some of which have not been reported elsewhere indicate the high nutritional potential of Saudi samh seeds . The total aerobic bacterial count and total sporeformers of seeds were 19 x 10(7) and 5 x 10(4) cfu/g respectively, thus the enterobacteriaceae, B cereus and yeast and molds were 5 x 10(2), 1 x 10(2) and 7 x 10(2) respectively . The seeds were Staph . free and the samh extract had no antimicrobial effect. Zhonghua Bing Li Xue Za Zhi, 1995 Oct, 24(5), 285 - 7 {A pathological comparison between Hirschsprung's enterocolitis and neonate necrotizing enterocolitis}; Zhang Z et al.; Autopsy records of 9 cases of neonate Hirschsprung's enterocolitis (HD) and 16 cases of neonate necrotizing enterocolitis (NEC) were analysed . It was found that the NEC lesions were more extensive than HD lesions, the bleeding and inflammation in NEC were also more serious than in HD . From our 21 animal experiments in which we tried to clarify the pathogenesis of Hirschsprung's enterocolitis and NEC, our preliminary hypothesis fro the development of Hirschsprung's enterocolitis being: the distal segment was first obstructed, causing the proximal segment to expand, the increase of pressure within the bowel resulted in ischemia of the intestines, increased bacterial multiplication in the retained feces and bacterial infiltration of the intestinal mucosa . The above being the major cause of HD . When the neonate is in asphyxia or shock, ischemia of the intestines and immunoallergic reactions occur, due to the lack of IgA in the mucosa, the multiplication and infiltration of pathogenic enterobacteria in the intestinal wall results in NEC. Clin Infect Dis, 1995 Oct, 21(4), 915 - 23 Molecular epidemiology of an SHV-5 extended-spectrum beta-lactamase in enterobacteriaceae isolated from infants in a neonatal intensive care unit; Venezia RA et al.; Klebsiella oxytoca that produced extended-spectrum beta-lactamase (ESBL) and were resistant to ceftazidime were isolated from infants in a neonatal intensive care unit (NICU) . During a 30-week period, 3 infants developed infections and an additional 60 infants were colonized with these bacteria . The molecular typing data suggested transmission of a single strain of ceftazidime-resistant K . oxytoca among 48 of the 63 infants . The ESBL of 46 of the 48 similar isolates, 14 of the remaining 15 isolates, and 6 other Enterobacteriaceae appeared to be associated with a conjugative plasmid of approximately 85 kb . The ESBL gene was cloned, and DNA sequencing confirmed that the ESBL was an SHV-5 . Hybridization data suggested that the SHV-5 gene was transmitted to other Enterobacteriaceae in vivo . The spread of the ESBL was reduced through adherence to infection control practices. J Vet Diagn Invest, 1995 Oct, 7(4), 506 - 8 Evaluation of a commercial automated system and software for the identification of veterinary bacterial isolates; Patten VH et al.; A commercial gram-negative bacterial autoidentification plate was originally developed using bacterial isolates of human origin . Three veterinary diagnostic laboratories conducted a 2-phase trial to enhance the database for veterinary use . The first phase consisted of testing the plate with 447 bacterial isolates of veterinary origin and incorporating that data into the existing database . Emphasis was placed on the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, since the Pseudomonas taxon was quite complete . The second phase of the trial consisted of evaluating the enhanced database using 270 clinical veterinary isolates normally encountered in veterinary laboratories . For the Actinobacillus, Bordetella, Pasteurella and Enterobacteriaceae groups, 72% of the bacterial isolates were identified correctly to genus and 85% to species after 18 hours incubation . All identifications in phase 1 and phase 2 were confirmed using conventional methods. New Microbiol, 1995 Oct, 18 Suppl, 19S - 31S {Preclinical evaluation of meropenem, a new parenteral carbapenem}; Edwards JR; Meropenem is a new carbapenem antibiotic that is stable to human renal dehydropeptidase-I (DHP-I) and exhibits potent bactericidal activity against almost all clinically significant aerobic and anaerobic bacteria . Activity is achieved through rapid entry into bacteria, resisting hydrolysis by all serine-based beta-lactamases, both of chromosomal or plasmid origin, and high affinity for vital penicillin binding proteins . The antibacterial spectrum of meropenem has been investigated extensively in a world-wide programme of studies . The results from all of these studies are consistent and identify in vitro differences between meropenem and imipenem . Both agents demonstrate high activity against Gram-positive aerobes with meropenem slightly less active than imipenem but significantly more potent than imipenem against Haemophilus influenza, all Enterobacteriaceae and 2-4 fold more active against Pseudomonas aeruginosa and most other pseudomonas . The spectrum of carbapenems is superior to that of all other beta-lactams . This is achieved, in part, by stability to the chromosomal beta-lactamases which hydrolyse ceftazidime, cefotaxime and ceftriaxone and against which newer agents like cefpirome and cefepime are not fully stable . Meropenem is also stable to the new plasmid-mediated enzymes which are responsible for significant elevation of MIC's of all cephalosporins and penicillins . When tested against P . Aeruginosa which have become resistant to imipenem therapy, these strains remained susceptible to meropenem . The activity of meropenem against anaerobes is at least as potent as metronidazole and clindamycin . These impressive in vitro data have been the basis for an extensive clinical evaluation programme in many indications including infections caused by single or multiple pathogens. New Microbiol, 1995 Oct, 18 Suppl, 1S - 17S {In vitro antibacterial activity of meropenem, a new carbapenem: European data}; Debbia EA et al.; Meropenem is a new DHP-I stable carbapenem with a very promising microbiological, pharmacokinetic and clinical profile . The antibacterial activity of this new agent has been assessed in vitro against 8741 aerobic and 854 anaerobic strains reflecting current incidence and epidemiology in Italy, France, Germany, Spain, Switzerland and United Kingdom . Comparator agents were imipenem, ceftriaxone, vancomycin, ciprofloxacin gentamicin and amikacin . The results of this study show that meropenem has a spectrum of antibacterial activity which embraces the vast majority of clinically significant Gram-positive and Gram-negative aerobes and anaerobes . This is due in part to excellent stability to chromosomal or plasmid mediated beta-lactamases including those which hydrolyse current cephalosporins . Data from the Italian study identified meropenem as the most potent agent against all Enterobacteriaceae, with the exception of Proteus species with were most susceptible to ciprofloxacin . Moreover, meropenem was 10 times more active than the other drugs against Haemophilus and Neisseria and was active against all the anaerobic strains . Conversely, staphylococci and enterococci were more susceptible to imipenem . Overall, these European data showed that meropenem was the most powerful drug against Enterobacteriaceae and it also was the most effective drug tested against the Italian and French Pseudomonas aeruginosa strains . Meropenem was less effective than imipenem or vancomycin against Enterococcus stains but had similar activity to imipen against anaerobes . Based on this microbiological profile, the use of meropenem is appropriate in the empirical treatment of serious infections, including those caused by multiple pathogens. Pediatr Emerg Care, 1995 Oct, 11(5), 280 - 4 Bacteremia and meningitis among infants with urinary tract infections; Bachur R et al.; A retrospective analysis of 354 patients < or = 2 years of age with urinary tract infections (UTIs) was performed to characterize patients with bacteremia or meningitis and to identify any objective predictors of these complications . Thirty-three patients with bacteremia were identified . Blood culture isolates included Escherichia coli (25), Staphylococcus aureus (4), enterococcus (1), group B Streptococcus (2), and Enterobacter (1) . Besides one patient with group B Streptococcus bacteremia at 1.5 months of age, all bacteremias after one month of age were with E . coli . Bacteremia was limited to those < 6 months old and inversely related to age (R = 0.24, P = 0.0008) . Grouped by age, the incidence of bacteremia was 21% for 0 < or = 1 month, 13% for 1.1-2.0 months, 4% for 2.1-3.0 months, and 8% for 3.1-6.0 months . Mean white blood cell count, initial temperature, initial serum bicarbonate, and erythrocyte sedimentation rate were not statistically significant between bacteremic (B) and nonbacteremic (NB) patients . Statistically significant differences were noted for percentage of bands (6.2% {NB} vs . 12.3% {B} P < 0.001), total band count (1048 {NB} vs . 2252 {B} P < 0.001), and band-neutrophil ratio (0.16 {NB} vs . 0.36 {B} P = 0.01); however, no practical value for any of these measures would reliably discriminate between bacteremic and nonbacteremic patients . Four patients, all neonates, had meningitis; too few patients with meningitis were identified for analysis . In summary, bacteremia with UTIs was observed to be inversely related to age and limited to patients less than six months of age . No objective parameters were identified to distinguish patients with bacteremia at the time of presentation. J Clin Microbiol, 1995 Oct, 33(10), 2601 - 6 Molecular identification of bacteria by fluorescence-based PCR-single-strand conformation polymorphism analysis of the 16S rRNA gene; Widjojoatmodjo MN et al.; PCR-single-strand conformation polymorphism (PCR-SSCP) analysis is a rapid and convenient technique for the detection of mutations and allelic variants . We have adapted this technique for the identification of bacteria by PCR with fluorescein-labeled primers chosen from the conserved regions of the 16S rRNA gene flanking a variable region . The PCR product was denatured, separated on a nondenaturing gel, and detected by an automated DNA sequencer . The mobility of the single-stranded DNA is sequence dependent and allows the identification of a broad panel of bacteria . A single nucleotide difference in the amplified region was sufficient to obtain different PCR-SSCP patterns . The simultaneous amplification of multiple polymorphic regions by multiplex PCR with subsequent multiplex SSCP increased the discriminatory power of PCR-SSCP . A broad range of gram-negative and gram-positive bacteria were tested by PCR-SSCP, including, e.g., Escherichia coli, Enterobacter spp., Klebsiella spp., Haemophilus spp., Neisseria spp., Staphylococcus spp, Streptococcus spp., Enterococcus spp., and Bacillus spp . In total, a panel of 178 strains of bacteria representing 51 species in 21 genera was examined . Although a limited number of strains from each species were tested, the strains tested gave species-specific patterns, with only one exception: Shigella species were indistinguishable from E . coli . PCR is a sensitive technique; as few as 10 CFU of E . coli was sufficient to produce PCR-SSCP patterns suitable for identification . The whole fluorescence PCR-SSCP procedure takes approximately 8 h for the detection and identification of low numbers of bacteria.2+ fluorescence PCR-SSCP seems to be a promising method for the differentiation of a broad range of pathogens found in usually sterile clinical sites, such as blood and cerebrospinal fluid. J Clin Microbiol, 1995 Oct, 33(10), 2525 - 9 Controlled clinical comparison of Isolator and BACTEC 9240 Aerobic/F resin bottle for detection of bloodstream infections; Pohlman JK et al.; A controlled clinical comparison was carried out with the BACTEC 9240 Aerobic/F resin bottle and the Isolator system with adult patients suspected of having bloodstream infections . A total of 10,500 paired specimens were collected, of which 1,122 from 520 patients were positive . There were 68 false-positive BACTEC bottles; 259 positive cultures that were excluded from analysis because the bottle, the Isolator, or both failed to meet the minimum volume criterion of 8 ml of blood; and 207 positive cultures that were excluded because the isolates were found to be clinically insignificant or of indeterminate clinical significance on the basis of patient assessment . A total of 656 positive cultures from 258 patients formed the basis of the analysis . Significantly more Staphylococcus aureus isolates (P = 0.03), Staphylococcus epidermidis isolates (P = 0.03), members of the family Enterobacteriaceae (P = 0.03), and Pseudomonas aeruginosa isolates (P = 0.04) were recovered from the resin bottle, and there was no category of organism that was recovered significantly more frequently from the Isolator system . With patients receiving antibiotics at the time of blood culture, S . aureus, S . epidermidis, and gram-negative bacilli were recovered significantly more frequently from the resin bottle . No significant differences between systems were found with cultures from patients not receiving antibiotics at the time of blood culture . Only 12 clinically significant organisms were recovered from the bottle on terminal subcultures, and only 1 of these had not been previously isolated from another blood culture set (10 of the 12) or from the companion Isolator (1 of 12) . The Aerobic/F resin bottle continuously monitored in the BACTEC 9240 instrument proved to be superior to the Isolator in overall yield of organisms causing bloodstream infection in adults and required less technician time for specimen processing and examination than the Isolator system. J Hosp Infect, 1995 Oct, 31(2), 99 - 104 Pyrolysis mass spectrometry of cephalosporin-resistant Enterobacter cloacae; Ahmet Z et al.; Thirteen clinical and four environmental isolates of third-generation cephalosporin-resistant Enterobacter cloacae (CREC) together with single isolates from the hands of a nurse and from a blood gas analyser were associated with two clusters of nosocomial infection . With an unrelated CREC isolate they had been typed by serotype, biotype, ribotype and phage-type and were examined by pyrolysis mass spectrometry (PYMS) as described here . PYMS data yielded two clusters, major and minor . All except one isolate in the major cluster corresponded to type group identity (serotype 07, biotype 62, ribotype D) which had caused neonatal sepsis and colonization . Multivariate analysis showed a homogeneous group consisting of this strain plus two outliers . The minor cluster included four different strains, one of which, serotype 03, biotype 62, ribotype C had caused excoriation of the buttocks and colonization. J Hosp Infect, 1995 Oct, 31(2), 89 - 97 Decreased transmission of Enterobacteriaceae with extended-spectrum beta-lactamases in an intensive care unit by nursing reorganization; Soulier A et al.; In our gastrointestinal surgical intensive care unit (SICU), the large number of patients with multiple enterostomies enhances the risk of nosocomial transmission of gut extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLE) by health care workers . A control study performed in our SICU from June-August 1992 showed an ESBLE gut colonization rate of 70% . To reduce this rate, nursing procedures were intensified or modified, particularly handwashing, single-use equipment and waste control . To test the efficiency of these procedures, 64 patients hospitalized for more than two days from September 1992-March 1993 were screened for gut acquisition of ESBLE . Rectal samples were taken within 48 h after admission and then weekly . After nursing reorganization, the ESBLE colonization rate dropped significantly to 40% (P < 0.001) . Twenty patients (31.7%) acquired a gut ESBLE, after a mean of 24.3 +/- 13.7 days . Each patient was colonized with one, two or three ESBLE (Klebsiella pneumoniae, Escherichia coli and Enterobacter aerogenes) . Baseline characteristics of the 20 colonized and 39 non-colonized patients showed no significant difference (Student's t-test, P > 0.05) . The nursing workload, estimated as a omega index, was greater in the colonized group (P < 0.001) . These findings show that strict observance of nursing procedures can significantly reduce ESBLE acquisition in a high-risk surgical unit. J Clin Pathol, 1995 Oct, 48(10), 929 - 32 Lethal synergy between toxins of staphylococci and enterobacteria: implications for sudden infant death syndrome; Sayers NM et al.; AIM--To test the hypothesis that lethal synergy occurs between toxin preparations of nasopharyngeal staphylococci and enterobacteria from sudden infant death syndrome (SIDS) victims and matched healthy infants . METHODS--SIDS and matched healthy babies were studied if both staphylococcal and enterobacterial strains were isolated from the nasopharynx . The lethality of toxin preparations from each bacterial isolate (separately and combined) was assessed over a range of dilutions using the chick embryo assay system . RESULTS--Staphylococci and enterobacteria were isolated together from the nasopharynx of seven SIDS babies but from only one normal healthy infant . Enterobacterial toxins were lethal at high dilutions . Staphylococcal toxins were less toxic . Simultaneous testing in the chick assay of staphylococcal and enterobacterial toxins, from each baby, at non-lethal concentrations enhanced lethality levels by 177 to 1011% compared with lethality expected by an additive effect alone . CONCLUSIONS--Synergy occurs between the toxins of nasopharyngeal staphylococci and enterobacteria . This combination of strains is more likely to occur in the nasopharynx of SIDS victims than that of healthy infants. Biosci Biotechnol Biochem, 1995 Oct, 59(10), 1938 - 43 Enzymatic synthesis of L-tryptophan by Enterobacter aerogenes tryptophanase highly expressed in Escherichia coli, and some properties of the purified enzyme; Kawasaki K et al.; We constructed two plasmids that have a strong tac promoter and a structural gene for tryptophanase of Enterobacter aerogenes SM-18 (pKT901EA) or Escherichia coli K-12 (pKT951EC) . The tryptophanase activity of E . coli JM109 transformed with pKT901EA (JM109/pKT901EA) was inducible with isopropyl-beta-D-thiogalactopyranoside, and 3.6 times higher than that of E . aerogenes SM-18 . Cells of JM109/pKT901EA induced for tryptophanase synthesized L-tryptophan from indole, ammonia, and pyruvate more efficiently than E . aerogenes SM-18 . Although JM109/pKT951EC expressed a similar level of tryptophanase activity to that of JM109/pKT901EA, the synthesis of L-tryptophan by the cells of JM109/pKT951EC did not proceed well compared with JM109/pKT901EA . Tryptophanases from E . aerogenes and E . coli K-12 were purified, and their properties were investigated . The purified E . aerogenes tryptophanase showed higher stability against heat inactivation than E . coli tryptophanase. J Appl Bacteriol, 1995 Oct, 79(4), 360 - 7 Efficiency of different enrichment and isolation procedures for the detection of Salmonella serotypes in edible offal; Arroyo G et al.; Rapid detection systems for Salmonella in foodstuffs are currently being developed . However, existing standards still call for application of traditional methods employing pre-enrichment followed by selective enrichment and isolation . The efficacy of various methods was tested using 264 chicken and lamb organ meats . Pre-enrichment was carried out in Tryptone Soy Broth (TSB) and enrichment in Tetrathionate Brilliant Green Broth (TTB) at 37 degrees C, Selenite Broth with Brilliant Green and Sulphapyridine at 37 degrees C and 43 degrees C, and Rappaport-Vassiliadis Broth (RV 10) at 42 degrees C . The isolation media were Brilliant Green Agar (BGA), Deoxycholate Citrate Agar, Hektoen Enteric Agar (HEA) and Salmonella-Shigella Agar . Enrichment in RV/42 degrees C followed by isolation on BGA as recommended by ISO standard no . 6579 and enrichment in TTB/37 degrees C followed by isolation in HEA, no longer recommended by that standard, produced the best results . Low percentages of positive samples and difficulties in detecting Salmonella are the result of interference by competing organisms (Enterobacteriaceae) and the number of salmonellas present after enrichment . A total of 528 samples (TSB, eggs, lamb liver and chicken liver) were inoculated with Salm . enteritidis, Salm . kapemba and Salm . virchow, and the preceding experiment was repeated . All the TSB and egg samples tested positive, but the percentage of positive samples from the lamb and chicken liver was only 81-92% . Recovery of the salmonellas did not depend upon the method employed or the serotype inoculated but instead on interference by competing flora and the numbers of Salmonella present in the samples. Epidemiol Infect, 1995 Oct, 115(2), 269 - 77 PCR-based characterization of Yersinia enterocolitica: comparison with biotyping and serotyping; Odinot PT et al.; PCR-based DNA fingerprinting was used to characterize 48 clinical isolates of Yersinia enterocolitica . The samples were examined by random amplified polymorphic DNA (RAPD-PCR) and inter-repeat PCR (IR-PCR) . IR-PCR with two enterobacterial repetitive intergenic consensus primers resulted in patterns which were poorly discriminated; 2 of 11 arbitrary primers (RAPD-PCR) provided sufficient discriminatory power . In comparisons with serotyping and biotyping, RAPD-fingerprinting was the most discriminatory technique and may therefore be a valuable epidemiological tool for the study of Y . enterocolitica infections. Microbiology, 1995 Oct, 141 ( Pt 10), 2535 - 42 A 17 kDa outer-membrane protein (Omp4) from Serratia marcescens confers partial resistance to bacteriocin 28b when expressed in Escherichia coli; Guasch JF et al.; A cosmid-based genomic library of Serratia marcescens N28b was introduced into Escherichia coli and clones were screened for a bacteriocin 28b insensitive phenotype . One clone was found that showed partial resistance to bacteriocin 28b . By using Tn5tac1 insertions it was shown that this phenotype was due to the expression in E . coli of an outer-membrane protein of 17 kDa (Omp4) . The DNA region defined by insertion mutagenesis was sequenced and found to contain an ORF of 515 bp . The deduced amino acid sequence has 172 residues with a theoretical molecular mass of 18.4 kDa . The protein contains an N-terminal signal sequence of 24 amino acid residues and, when compared to other enterobacterial outer-membrane proteins, most closely resembles a family of small outer-membrane proteins of Enterobacteriaceae whose known functions appear to be related with virulence . Immunoblotting experiments showed that Omp4 is present in 15 biotypes of S . marcescens . The bacteriocin 28b resistance phenotype conferred on E . coli by Omp4 appears to be pleiotropic since overexpression of the Omp4-encoding gene leads to a decrease in the amount of OmpA, OmpF and/or OmpC; OmpA and OmpF are the receptors for bacteriocin 28b in E . coli. J Bacteriol, 1995 Oct, 177(19), 5539 - 46 Genetic analysis of the dTDP-rhamnose biosynthesis region of the Escherichia coli VW187 (O7:K1) rfb gene cluster: identification of functional homologs of rfbB and rfbA in the rff cluster and correct location of the rffE gene; Marolda CL et al.; The O-repeating unit of the Escherichia coli O7-specific lipopolysaccharide is made of galactose, mannose, rhamnose, 4-acetamido-4,6-dideoxyglucose, and N-acetyglucosamine . We have recently characterized the genes involved in the biosynthesis of the sugar precursor GDP-mannose occurring in the E . coli O7:K1 strain VW187 (C . L . Marolda and M . A . Valvano, J . Bacteriol . 175:148-158, 1993) . In the present study, we identified and sequenced the rfbBDAC genes encoding the enzymes for the biosynthesis of another precursor, dTDP-rhamnose . These genes are localized on the upstream end of the rfbEcO7 region, and they are strongly conserved compared with similar genes found in various enteric and nonenteric bacteria . Upstream of rfbB we identified a DNA segment containing the rfb promoter and a highly conserved untranslated leader sequence also present in the promoter regions of other surface polysaccharide gene clusters . Also, we have determined that rfbB and rfbA have homologs, rffG (o355) and rffH (o292), respectively, located on the rff cluster, which is involved in the synthesis of enterobacterial common antigen . We provide biochemical evidence that rffG and rffH encode dTDP-glucose dehydratase and glucose-1-phosphate thymidylyltransferase activities, respectively, and we also show that rffG complemented the rfbB defect in the O7+ cosmid pJHCV32 . We also demonstrate that rffG is distinct from rffE and map the rffE gene to the second gene of the rff cluster. Int J Syst Bacteriol, 1995 Oct, 45(4), 848 - 51 Wigglesworthia gen . nov . and Wigglesworthia glossinidia sp . nov., taxa consisting of the mycetocyte-associated, primary endosymbionts of tsetse flies; Aksoy S; The primary endosymbionts (P-endosymbionts) of tsetse flies (Diptera: Glossinidae) are harbored inside specialized cells (mycetocytes) in the anterior region of the gut, and these specialized cells form a white, U-shaped organelle called mycetome . The P-endosymbionts of five tsetse fly species belonging to the Glossinidae have been characterized morphologically, and their 16S ribosomal DNA sequences have been determined for phylogenetic analysis . These organisms were found to belong to a distinct lineage related to the family Enterobacteriaceae in the gamma subdivision of Proteobacteria, which includes the secondary endosymbionts of various insects and Escherichia coli . These bacteria are also related to the P-endosymbionts of aphids, Buchnera aphidicola . Signature sequences in the 16S ribosomal DNA and genomic organizational differences which distinguish the tsetse fly P-endosymbionts from members of the Enterobacteriaceae and from the genus Buchnera are described in this paper . I propose that the P-endosymbionts of tsetse flies should be classified in a new genus, the genus Wigglesworthia, and a new species, Wigglesworthia glossinidia . The P-endosymbiont found in the mycetocytes of Glossina morsitans morsitans is designated the type strain of this species. Arch Microbiol, 1995 Oct, 164(4), 280 - 9 Lipopolysaccharide of Rhodospirillum salinarum 40: structural studies on the core and lipid A region; Rau H et al.; The structural elucidation of lipid A of the cell wall lipopolysaccharide (LPS) of Rhodospirillum salinarum 40 by chemical methods and laser desorption mass spectrometry revealed the presence of a mixed lipid A composed of three different 1,4'bisphosphorylated beta (1 --> 6)-linked backbone hexosaminyl-hexosamine disaccharides, i.e . those composed of GlcN --> GlcN, 2,3-diamino-2,3-dideoxy-D-Glc-(DAG --> DAG, and DAG --> GlcN . Lipid A of R . salinarum contained preferentially 3-OH-18:0 and 3-OH-14:0 as amide-linked and cis delta 11-18:1 and c19:0 as ester-linked fatty acids . The mass spectra of the liberated acyl-oxyacyl residues proved the concomitant presence of 3-O-(cis delta 11-18:1)-18:0 and 3-O-(c19:0)-14:0 as the predominating diesters in this mixed lipid A . The glycosidically linked and the ester-linked phosphate groups of the backbone disaccharide were neither substituted by ethanolamine, phosphorylethanolamine, nor by 4-amino-4-deoxy-L-arabinose, in contrast to most of the enterobacterial lipid As . In the core oligosaccharide fraction, a HexA (1 --> 4)HexA(1 --> 5)Kdo-trisaccharide was identified by methylation analysis . The terminal HexA (hexuronic acid) is possibly 4-OMe-GalA, a component described here as an LPS constituent for the first time . LPS of R . salinarum showed a lethality in C57BL/10 ScSN (LPS-responder)-mice) of an order of 10(-1)-10(-2) of that reported for Salmonella abortus equi LPS, and it was also capable of inducing TNF alpha and IL6 in macrophages of C57BL/10ScSN mice. Schweiz Med Wochenschr, 1995 Sep 9, 125(36), 1684 - 6 {Epidemiology of antibiotic resistance: implications for empirical treatment in intensive care}; Wolff M; The adequacy of initial antibiotic therapy is an important prognostic factor in severe infections . Concerning nosocomial infections, the selection of appropriate empirical therapy should take into account the incidence of offending pathogens within a specific unit . The changing trends in the hospital's microbial resistance patterns should be known to the physicians . The bacteria involved and the susceptibility testing vary widely among institutions and among countries . Many risk factors for acquisition of resistant pathogens have been identified . The duration of stay in hospital, previous colonization, and antibiotic treatment are the most frequently cited risk factors . When P . aeruginosa is suspected, an ureido-penicillin/aminoglycoside combination is usually effective . However, in some units with high levels of resistance, the beta-lactam should be ceftazidime or imipenem . When enterobacteria are suspected, a third generation cephalosporin, alone or in combination with an amino-glycoside or a broad spectrum penicillin associated with a beta-lactamase inhibitor is appropriate . Early nosocomial staphylococcal infections are treated with nafcillin or oxacillin, alone or in combination with an aminoglycoside . In units with a high rate of MRSA, the initial antibiotic therapy should include a glycopeptide. J Antimicrob Chemother, 1995 Sep, 36(3), 513 - 9 Effect of pO2 and pH on synergy of tazobactam and beta-lactam antibiotics against beta-lactamase producing Enterobacteriaceae; Konig C et al.; Synergy between tazobactam and ceftriaxone or piperacillin against beta-lactamase producing Enterobacteriaceae was not influenced by the presence or absence of oxygen . For most strains synergy was excellent at neutral pH but reduced in acidic conditions . Low pH increased 50% of the MICs up to or beyond the sensitivity breakpoint. Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1995 Sep, 11(5), 327 - 9 {An investigation into antibiotic resistance and plasmid pattern of Enterobacter cloacae in burn infection}; Li Y et al.; In view of a high positive isolation rate and resistance to antibiotics of Enterobacter cloacae in our department, 32 strains of E . cloacae, which were isolated from blood and infected wounds of burned patients from June through November 1990, were randomly selected to determine their susceptibility to 21 antibiotics and their plasmid patterns . It was found that 29 of 32 strains were resistant to at least nine antibiotics, while the other three strains were relatively sensitive . 27 of 32 strains of E . cloacae were tested for plasmid, and among them, three strains (relatively sensitive to antibiotics) contained no plasmid . The plasmid patterns of the other 24 isolates varied with strains, but all of them had a 80 kb plasmid . The 80 kb plasmid was obviously related to the high isolation rate and high resistance to antibiotics of E . cloacae isolated in our department. Mol Microbiol, 1995 Sep, 17(6), 1167 - 75 A cell-surface polysaccharide that facilitates rapid population migration by differentiated swarm cells of Proteus mirabilis; Gygi D et al.; Swarming by Proteus mirabilis is characterized by cycles of rapid population migration across surfaces, following differentiation of typical vegetative rods into long, hyperflagellated, virulent swarm cells . A swarm-defective TnphoA insertion mutant was isolated that was not defective in cell motility, differentiation or control of the migration cycle, but was specifically impaired in the ability to undergo surface translocation as a multicellular mass . The mutation, previously shown to compromise urinary tract virulence, was located within a 1112 bp gene that restored normal swarming of the mutant when expressed in trans . The gene encoded a 40.6 kDa protein that is related to putative sugar transferases required for lipopolysaccharide (LPS) core modification in Shigella and Salmonella . The immediately distal open reading frame encoded a protein that is related to dehydrogenases involved in the synthesis of LPS O-side-chains, enterobacterial common antigen and extracellular polysaccharide (PS) . Gel electrophoresis and electron microscopy showed that the mutant still made LPS but it had lost the ability to assemble a surface (capsular) PS, which gas-liquid chromatography and mass spectrometry indicated to be an acidic type II molecule rich in galacturonic acid and galactosamine . We suggest that this surface PS facilitates translocation of differentiated cell populations by reducing surface friction. FEMS Immunol Med Microbiol, 1995 Sep, 12(1), 47 - 50 Salmonella enterotoxin (stn) gene is prevalent among strains of Salmonella enterica, but not among Salmonella bongori and other Enterobacteriaceae; Prager R et al.; All strains and serovars of Salmonella enterica such as serovar Typhimurium, Enteritidis, Dublin, Typhi, etc . were found to carry the Salmonella enterotoxin determinant stn as far as examined in PCR and hybridization studies . However, using MDCK cells for testing the toxicity of the strains under investigation, only a limited number of stn positive strains revealed phenotypically the Salmonella enterotoxin Stn . In contrast to S . enterica, other Enterobacteriaceae including Salmonella bongori were found neither genotypically nor phenotypically Stn toxin positive. Mikrobiol Z, 1995 Sep-Oct, 57(5), 3 - 15 {Gram-negative bacteria contaminating the process of producing lysine}; Vasilevskaia IA et al.; The authors have isolated Gram-negative bacteria of the Enterobacteriaceae family from the culture liquid of industrial fermenters with low yield of lysine . Most of them possessed the characters typical of Klebsiella pneumoniae and Escherichia coli, the rest were identified as the representatives of genera Proteus, Providencia, Enterobacter, Hafnia . Strains of Klebsiella pneumoniae, E.coli, Proteus rettgeri manifested lysine-decarboxylase activity . The capacity of some strains to destruct lysine synthesized by the target culture in the process of fermentation with formation of cadaverin was experimentally proved and confirmed under production conditions . Technological water is the source of distribution of gram-negative bacteria (first of all Klebsiella) in lysine production. Microb Pathog, 1995 Sep, 19(3), 139 - 57 Binding specificity for four monoclonal antibodies recognizing terminal Gal alpha 1-->4Gal residues in Haemophilus influenzae lipopolysaccharide; Borrelli S et al.; Four murine monoclonal antibodies (MAbs) reactive with the outer-core region of the lipopolysaccharide (LPS) from Haemophilus influenzae were generated after immunization with azide-killed H . influenzae RM.7004 AH1-2 and their epitope specificities studied . The monoclonal antibodies: MAHI 6 (IgM), MAHI 5 (IgG2a), MAHI 8 (IgG3), and MAHI 11 (IgG2b) bound to synthetic glycoconjugates or glycolipids with terminal galabiosyl (Gal alpha 1-->4Gal beta 1-) or globotriaosyl (Gal alpha 1-->4Gal beta 1 1-->4GLc) residues as evaluated in enzyme immunoassays (EIA) . Glycoconjugates or glycolipids with internally placed galabiose elements were not active, indicating selectively of the MAbs for recognition of the epitope . Nine LPSs from H . influenzae inhibited the binding of the four MAbs . The presence of the galabiosyl disaccharide element in these nine LPSs was evidence by the binding of 125I-labeled Shiga toxin isolated from the bacterium Shigella dysenteriae type 1, reported to have as receptor the Gal alpha 1-->4Gal beta disaccharide (Lindberg et al., J Biol Chem, 1987, 262: 1779-85) . Structural studies of these H . influenzae LPSs were also in accord with the presence of the galabiosyl disaccharide, in addition 1H-NMR spectroscopy showed the presence of O-acetyl groups in the RM.7004 AH1-2 LPS . However, differential binding specificities of the MAbs to modified RM.7004 AH1-2 LPSs were observed . MAHI 6 and MAHI 11 bound equally well to LPS, polysaccharides obtained after mild acidic treatment, and dephosphorylated LPS samples as shown in inhibition EIA . In contrast, both dephosphorylated LPS samples and polysaccharides were poorer inhibitors of the binding of MAHI 5 and MAHI 8 to native RM.7004 AH1-2 LPS . Neither the de-O-acylated nor the de-O,N-acylated LPSs were effective inhibitors of any of the four MAbs . These results suggest that the MAbs recognition involves Gal alpha 1-->4Gal and O-acetyl and other saccharide residue(s) from the oligosaccharide moiety of the LPS . The epitopes are also expressed and accessible to recognition in clinical isolates coming from different sources of Neisseria spp., Haemophilus spp., and Moraxella catarrhalis, but not in Bordetella spp., Aeromonas spp . or Enterobacteriaceae as evaluated by whole-bacteria EIA and colony-dot-immunoblotting. Chemotherapy, 1995 Sep-Oct, 41(5), 345 - 52 Piperacillin tazobactam compared with co-amoxiclav, ampicillin plus sulbactam and timentin against beta-lactamase-producing clinical isolates of Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca; Traub WH et al.; A total of 266 enterobacterial isolates (Escherichia coli = 190, Klebsiella pneumoniae = 49, K . oxytoca = 27) were tested for susceptibility (Bauer-Kirby agar disk diffusion test and agar dilution procedure) to ampicillin, ampicillin in 10 micrograms/ml of sulbactam, amoxicillin in 4 micrograms/ml of clavulanic acid, piperacillin, piperacillin plus tazobactam (8:1 ratio), ticarcillin and timentin (ticarcillin in 4 micrograms/ml of clavulanic acid) . Discrepant results between the two methods of susceptibility testing were categorized as follows: category I = very major {minimal inhibitory concentration (MIC) = resistant, disk diffusion = susceptible} category II = major (MIC = susceptible, disk diffusion = resistant), category III = minor (MIC = intermediate susceptibility, disk diffusion = susceptible), category IV = slight (MIC = resistant, disk diffusion = intermediate), category V = minimal (MIC = susceptible, disk diffusion = intermediate) and category VI = negligible (MIC = intermediate, disk diffusion = resistant) . The antibiotics, or combinations with beta-lactamase inhibitors, yielded the following discrepant results: ampicillin (II = 2, V = 1 and VI = 3), co-amoxiclav (I = 5, III = 25, IV = 1 and V = 3), ampicillin plus sulbactam (I = 5, II = 3, III = 1, V = 19 and VI = 1), piperacillin (II = 15, III = 1, V = 15 and VI = 85), piperacillin plus tazobactam (III = 16, IV = 2, V = 1 and VI = 5) and timentin (I = 2, III = 48 and IV = 1).(ABSTRACT TRUNCATED AT 250 WORDS) Am J Clin Pathol, 1995 Sep, 104(3), 279 - 82 Evaluation of routine anaerobic blood cultures in the BacT/Alert blood culture system; Bannister ER et al.; To evaluate the use of routine anaerobic blood cultures with the BacT/Alert system, results of 12,289 blood culture sets collected from adults over a 9-month period were reviewed . Of the sets included in the study, 1,306 (10.6%) from 808 patients grew 1 or more organisms . Anaerobes were present in 39 sets from 38 patients . Of the positive sets, both bottles were positive in 60.7% of cases, the aerobic bottle only in 23.7%, and the anaerobic bottle only in 15.6% . When only the 254 patients who had 2 or more positive sets were considered, both bottles were positive in 71.5% of cases, the aerobic bottle only in 20.7%, and the anaerobic only in 7.8% . In this subset of patients gram-positive bacilli, gram-negative bacilli other than Enterobacteriaceae, and yeasts grew significantly more frequently in aerobic bottle . No organisms preferred the anaerobic bottle . These data support the selective use of the BacT/Alert anaerobic blood culture bottle in patients at risk for anaerobic bacteremia. J Bacteriol, 1995 Sep, 177(17), 5108 - 15 Identification of a global repressor gene, rsmA, of Erwinia carotovora subsp . carotovora that controls extracellular enzymes, N-(3-oxohexanoyl)-L-homoserine lactone, and pathogenicity in soft-rotting Erwinia spp; Cui Y et al.; The production of extracellular enzymes such as pectate lyase (Pel), polygalacturonase (Peh), cellulase (Cel), and protease (Prt) is activated by the cell density (quorum)-sensing signal, N-(3-oxohexanoyl)-L-homoserine lactone (HSL); plant signals; and aep genes during postexponential growth of Erwinia carotovora subsp . carotovora 71 . Studies with mutants of E . carotovora subsp . carotovora 71 derepressed in exoenzyme production led to the identification of a negative regulator gene, rsmA (rsm, repressor of secondary metabolites) . Nucleotide sequencing, transcript assays, and protein analysis established that a 183-bp open reading frame encodes the 6.8-kDa RsmA . rsmA has extensive homology with the csrA gene of Escherichia coli, which specifies a negative regulator of carbon storage . Moreover, the suppression of glycogen synthesis in E . coli by rsmA indicates that the Erwinia gene is functionally similar to csrA . Southern hybridizations revealed the presence of rsmA homologs in soft-rotting and non-soft-rotting Erwinia spp . and in other enterobacteria such as Enterobacter aerogenes, E . coli, Salmonella typhimurium, Shigella flexneri, Serratia marcescens, and Yersinia pseudotuberculosis . rsmA suppresses production of Pel, Peh, Cel, and Prt, plant pathogenicity, and synthesis of HSL in E . carotovora subsp . atroseptica, E . carotovora subsp . betavasculorum, E . carotovora subsp . carotovora, and E . chrysanthemi . In the E . carotovora subsp . carotovora 71, rsmA reduces the levels of transcripts of hslI, a luxI homolog required for HSL biosynthesis . This specific effect and the previous finding that HSL is required for extracellular enzyme production and pathogenicity in soft-rotting Erwinia spp . support the hypothesis that rsmA controls these traits by modulating the levels of the cell density (quorum)-sensing signal. Am J Respir Crit Care Med, 1995 Sep, 152(3), 1028 - 33 Pattern of tracheal colonization during mechanical ventilation; de Latorre FJ et al.; The relationship between gastric (GC) and tracheal (TC) colonization and the development of ventilator-associated pneumonia (VAP) remains controversial . TC, GC, and pharyngeal (PC) colonization were studied serially in 80 patients with mechanical ventilation (MV) to ascertain the routes and onset of TC . Simultaneous sample from pharynx, stomach, and trachea were obtained throughout the MV period . Quantitative cultures were performed . Seventy-two patients (90%) had TC at some time during MV . Only 19 patients presented TC after PC or GC by the same microorganisms . Indigenous gram-negative and gram-positive microorganisms colonized mainly the trachea from the start of or during MV without previous PC or GC (p < 0.05) . Pseudomonas were the microorganisms causing TC principally during MV without previous PC or GC (p < 0.005) . Enterobacteria produced TC without a preferential route . Of the 12 patients who developed VAP, the microorganisms responsible had already colonized the trachea in 10 patients . Only 10 of the 21 microorganisms isolated in VAP had previously colonized the pharynx or stomach . In summary, although some microorganisms have preferential routes for producing TC, the microorganisms isolated frequently change during MV . TC precedes VAP in most patients, but only a minority develop a VAP; therefore, together with TC other factors must be involved in VAP development. Lett Appl Microbiol, 1995 Sep, 21(3), 160 - 3 Evaluation of the BBL Crystal Enteric/Nonfermenter kit for the identification of water-derived environmental Enterobacteriaceae; Micklewright IJ et al.; The Crystal Enteric/Nonfermenter (E/NF) identification kit (Becton Dickinson Microbiology Systems, USA) was evaluated using water-derived bacterial isolates and results compared to those obtained by the API 20E system (BioMerieux, UK) . Both the E/NF and 20E systems correctly identified 93% of the Enterobacteriaceae reference cultures . Both systems agreed in the identification of 64.9% of environmental isolates . The E/NF system gave a positive identification to 88.0% of isolates and the 20E to 79.5% of isolates . The principal tests which gave differing reactions between the two systems were arginine dihydrolase, lysine decarboxylase, urease and citrate utilization. Infect Immun, 1995 Sep, 63(9), 3683 - 92 The tetrasaccharide L-alpha-D-heptose1-->2-L-alpha-D-heptose1--> 3-L-alpha-D-heptose1-->(3-deoxy-D-manno-octulosonic acid) and phosphate in lipid A define the conserved epitope in Haemophilus lipopolysaccharides recognized by a monoclonal antibody; Borrelli S et al.; A murine monoclonal antibody, MAHI 3 (immunoglobulin G2b), that is broadly reactive with Haemophilus influenzae lipopolysaccharides (LPSs) but nonreactive with all enterobacterial LPSs tested was generated by fusing mouse myeloma cells with spleen cells of BALB/c mice immunized with azide-killed H . influenzae RM.7004 . MAHI 3 bound to all H . influenzae, all other human Haemophilus spp., all Bordetella pertussis and Bordetella parapertussis, and all Aeromonas spp . tested but not to any Neisseria or Moraxella catarrhalis strains, as determined by enzyme immunoassay, colony dot immunoblotting, and immunoblotting . In an inhibition enzyme immunoassay, MAHI 3 reacted with all 45 H . influenzae LPSs tested but not with the LPS from the rough mutant I69 Rd-/b+, which has only 3-deoxy-D-manno-octulosonic acid (P) {Kdo(P)} and lipid A . The antibody was not inhibited by H . influenzae lipid A or lipid-free polysaccharide isolated after mild acid hydrolysis . Only native LPSs show positive inhibitory activity, indicating that part of lipid A is involved in the binding of MAHI 3 . From the results, it is indicated that the structural element recognized by MAHI 3 is Hep alpha 1-->2Hep alpha 1-->3Hep alpha 1-->Kdo together with part of lipid A, including the phosphate. J Hosp Infect, 1995 Sep, 31(1), 61 - 6 DNA fingerprinting of Pseudomonas aeruginosa serotype O11 by enterobacterial repetitive intergenic consensus-polymerase chain reaction and pulsed-field gel electrophoresis; Lau YJ et al.; We report the use of pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based polymerase chain reaction (PCR) to characterize clinical isolates of Pseudomonas aeruginosa serotype O11 collected from an incident of hospital-acquired infection . Both typing techniques differentiated 20 different strain types among seven epidemiologically related isolates and 22 epidemiologically unrelated isolates . There was complete concordance between these two techniques . Our results indicate that the ERIC-based PCR technique represents a rapid and simple means for typing P . aeruginosa serotype O11 with a level of discrimination equivalent to that of PFGE. Microbiology, 1995 Sep, 141 ( Pt 9), 2157 - 64 Distribution of the ardA family of antirestriction genes on conjugative plasmids; Chilley PM et al.; The ardA gene of I1 plasmid ColIb-P9 was previously shown to alleviate DNA restriction by type I enzymes and to promote conjugative transmission of the unmodified plasmid to a restricting host . To clarify the ecological role of ardA, its distribution was determined on plasmids from 23 incompatibility groups using hybridization to the coding sequence as an assay . Hybridizing sequences, shown by nucleotide sequencing to have at least 60% identity with ardA, were detected on plasmids belonging to the I complex (IncB, I1 and K), the F complex (IncFV) and the IncN group . The ardA homologues were found to specify an antirestriction phenotype which was enhanced by genetic depression of the plasmid transfer system . ardA loci map in plasmid leading regions but show no consistent association with a particular type of origin-of-transfer or a leading region gene of the ssb (single-stranded DNA-binding protein), psiB (plasmid SOS inhibition) and hok (host killing) families . It may be significant that ardA+ plasmids are authentic enterobacterial plasmids and that type I restriction systems are associated historically with members of the Enterobacteriaceae. J Clin Microbiol, 1995 Sep, 33(9), 2372 - 6 Characterization of Hafnia alvei by biochemical tests, random amplified polymorphic DNA PCR, and partial sequencing of 16S rRNA gene; Ridell J et al.; Hafnia alvei strains which possess the attachment-effacement gene (eaeA) may have clinical importance as new diarrhea-causing pathogens and should therefore be differentiated from other H . alvei strains . We characterized diarrheal H . alvei strains, which were positive in the PCR test for the eaeA gene, using biochemical tests not routinely used for identification of members of the family Enterobacteriaceae, and compared them with eaeA-negative strains isolated from different clinical and nonclinical sources to find characteristics useful for identification . Random amplified polymorphic DNA (RAPD)-PCR and partial sequencing of the 16S rRNA gene were utilized to study the genetic diversity of the isolates . The eaeA-positive strains were found to have many characteristic biochemical properties . Negative reactions in the 2-ketogluconate and histidine assimilation tests and a positive reaction in the 3-hydroxybenzoate assimilation test may be useful in routine diagnostics . Nearly identical RAPD-PCR profiles and identical 353-bp fragments of the 16S rRNA genes indicated little genetic diversity among the eaeA-positive strains . The low level of homology (92%) in the partial 16S rRNA genes of eaeA-positive and -negative H . alvei strains raises questions about the taxonomic positioning of eaeA-positive H . alvei. Pharm Acta Helv, 1995 Sep, 70(3), 227 - 32 Microbiological quality of pharmaceutical raw materials; de la Rosa MC et al.; A total of 115 samples of pharmaceutical raw materials (excipients) were analysed: 36 lactose, 27 talc, 19 corn starch, 18 arabic gum, 8 gelatin, 3 gelatinized starch, 3 cellulose and one tragacanth gum . 69.9% of the samples showed less than 10(2) bacteria/g (mean = 23.2 cfu/g) and 95.2% less than 10(2) fungi/g (mean = 4.92 cfu/g) . Arabic and tragacanth gum were the most contaminated products by bacteria and fungi, respectively . Pregelatinized starch, cellulose and lactose were the least contaminated excipients . In none of the samples Escherichia coli or Salmonella-Shigella were detected; however, strains of Enterobacter, Serratia and Proteus were isolated from 10 samples of 5 different excipients . Only 5 samples did not comply with the microbiological standards as established by the European Pharmacopoeia and USP. Carbohydr Res, 1995 Aug 25, 273(2), 157 - 70 Determination by NMR spectroscopy of the structure and conformational features of the enterobacterial common antigen isolated from Escherichia coli; Bruix M et al.; Complete 1H and 13C spectrum of a polysaccharide isolated from Escherichia coli, which is the major component of the enterobacterial common antigen, has been analyzed through two-dimensional nuclear magnetic resonance spectroscopy . In addition, distance constraints from NOESY and ROESY experiments have been combined with molecular dynamic simulations to determine its major conformation in water solution . Data resulting from both free dynamic simulations and restrained dynamic simulations have been compared with experimental data and discussed. JAMA, 1995 Aug 23-30, 274(8), 639 - 44 The prevalence of nosocomial infection in intensive care units in Europe . Results of the European Prevalence of Infection in Intensive Care (EPIC) Study . EPIC International Advisory Committee; Vincent JL et al.; OBJECTIVE--To determine the prevalence of intensive care unit (ICU)-acquired infections and the risk factors for these infections, identify the predominant infecting organisms, and evaluate the relationship between ICU-acquired infection and mortality . DESIGN--A 1-day point-prevalence study . SETTING--Intensive care units in 17 countries in Western Europe, excluding coronary care units and pediatric and special care infant units . PATIENTS--All patients (> 10 years of age) occupying an ICU bed over a 24-hour period . A total of 1417 ICUs provided 10 038 patient case reports . MAIN OUTCOME MEASURES--Rates of ICU-acquired infection, prescription of antimicrobials, resistance patterns of microbiological isolates, and potential risk factors for ICU-acquired infection and death . RESULTS--A total of 4501 patients (44.8%) were infected, and 2064 (20.6%) had ICU-acquired infection . Pneumonia (46.9%), lower respiratory tract infection (17.8%), urinary tract infection (17.6%), and bloodstream infection (12%) were the most frequent types of ICU infection reported . Most frequently reported micro-organisms were Enterobacteriaceae (34.4%), Staphylococcus aureus (30.1%;{60% resistant to methicillin}, Pseudomonas aeruginosa (28.7%), coagulase-negative staphylococci (19.1%), and fungi (17.1%) . Seven risk factors for ICU-acquired infection were identified: increasing length of ICU stay (> 48 hours), mechanical ventilation, diagnosis of trauma, central venous, pulmonary artery, and urinary catheterization, and stress ulcer prophylaxis . ICU-acquired pneumonia (odds ratio {OR}, 1.91; 95% confidence interval{Cl}, 1.6 to 2.29), clinical sepsis (OR, 3.50; 95% Cl, 1.71 to 7.18), and bloodstream infection (OR, 1.73; 95% Cl, 1.25 to 2.41) increased the risk of ICU death . CONCLUSIONS--ICU-acquired infection is common and often associated with microbiological isolates of resistant organisms . The potential effects on outcome emphasize the importance of specific measures for infection control in critically ill patients. Cancer Res, 1995 Aug 15, 55(16), 3558 - 63 Regressions and cures of melanoma xenografts following treatment with monoclonal antibody beta-lactamase conjugates in combination with anticancer prodrugs; Kerr DE et al.; Cephalosporin doxorubicin (C-Dox) and 7-(4-carboxybutanamido)-cephalosporin mustard (CCM) are prodrugs that are catalytically converted by Enterobacter cloacae beta-lactamase (bL) to the active anticancer agents doxorubicin and phenylenediamine mustard, respectively . Both prodrugs were less cytotoxic to the 3677 human melanoma line than their respective drugs and were activated in an immunologically specific manner by 96.5-bL, a mAb-bL conjugate that binds to 3677 cell surface antigens . Similar results were obtained using the CCM prodrug on SK-MEL 28 human melanoma cells . Experiments in mice with established s.c . 3677 tumors demonstrated that although no tumors were cured in mice receiving the 96.5-bL/C-Dox combination, the activities were greater than those obtained from systemic doxorubicin treatment or from