Carbohydr Res, 2001 Apr 12, 331(3), 331 - 6 Structure of the O-specific polysaccharide isolated from the lipopolysaccharide of Citrobacter gillenii serotype O12a, 12b strain PCM 1544; Kubler-Kielb J et al.; A neutral O-specific polysaccharide was isolated from the lipopolysaccharide of Citrobacter gillenii strain PCM 1544, representing serotype O12a,12b . The polysaccharide was studied by sugar and methylation analyses and Smith degradation along with 1H and 13C NMR spectroscopy, including a ROESY experiment . The following structure of the tetrasaccharide repeating unit was established, in which substitution with terminal GlcNAc is approximately 60% . {structure: see text} Exp Anim, 2001 Apr, 50(2), 183 - 6 Comparison of bacteriological, genetic and pathological characters between Escherichia coli O115a,c:K(B) and Citrobacter rodentium; Okutani A et al.; Murine pathogenic Escherichia coli O115a,c:K(B) (MPEC) is the causative agent of mouse megaenteron, the pathology of which resembles that of transmissible murine colonic hyperplasia caused by Citrobacter rodentium . We compared their genetic and pathological features to reveal the relationship between these two bacteria . To evaluate the genetic distances, 16S rDNA genes were sequenced and biochemical reactions were tested . Mouse strain susceptibility tests, using CF1 MPEC-susceptible germfree mice and BALB/cA(Jic) resistant mice were performed . MPEC strains and C . rodentium showed more than 99.6% identity by comparison of 16S rDNA gene sequences . All results from biochemical reactions and the mouse strain susceptibility tests were identical . It is proposed that MPEC should be reclassified as C . rodentium. Biotechniques, 2001 May, 30(5), 1044 - 8, 1050-1 Use of an ALFexpress DNA sequencer to analyze protein-nucleic acid interactions by band shift assay; Filee P et al.; Gel retardation analysis, or band shift assay, is technically the simplest method to investigate protein-nucleic acid interactions . In this report, we describe a nonradioactive band shift assay using a fluorescent DNA target and an ALFexpress automatic DNA sequencer in place of the current method that utilizes radioactively end-labeled DNA target and a standard electrophoresis unit . In our study, the dsDNA targets were obtained by annealing two synthetic oligonucleotides or by PCR . In both cases, a molecule of indodicarbocyanine (CY5) was attached at the 5' OH end of one of the two synthetic oligonucleotides, with a ratio of one molecule of fluorescent dye per molecule of dsDNA . To demonstrate the feasibility of this new band shift assay method, the DNA-binding proteins selected as models were the BlaI and AmpR repressors, which are involved in the induction of the Bacillus licheniformis 749/I and Citrobacter freundii beta-lactamases, respectively . The results show that the use of an automatic DNA sequencer allows easy gel retardation analysis and provides a fast, sensitive, and quantitative method . The ALFexpress DNA sequencer has the same limit of detection as a laser fluorescence scanner and can be used instead of a FluorImager or a Molecular Imager. J Bacteriol, 2001 Jun, 183(11), 3417 - 27 Identification and functional characterization of arylamine N-acetyltransferases in eubacteria: evidence for highly selective acetylation of 5-aminosalicylic acid; Delomenie C et al.; Arylamine N-acetyltransferase activity has been described in various bacterial species . Bacterial N-acetyltransferases, including those from bacteria of the gut flora, may be involved in the metabolism of xenobiotics, thereby exerting physiopathological effects . We characterized these enzymes further by steady-state kinetics, time-dependent inhibition, and DNA hybridization in 40 species, mostly from the human intestinal microflora . We report for the first time N-acetyltransferase activity in 11 species of Proteobacteriaceae from seven genera: Citrobacter amalonaticus, Citrobacter farmeri, Citrobacter freundii, Klebsiella ozaenae, Klebsiella oxytoca, Klebsiella rhinoscleromatis, Morganella morganii, Serratia marcescens, Shigella flexneri, Plesiomonas shigelloides, and Vibrio cholerae . We estimated apparent kinetic parameters and found that 5-aminosalicylic acid, a compound efficient in the treatment of inflammatory bowel diseases, was acetylated with a catalytic efficiency 27 to 645 times higher than that for its isomer, 4-aminosalicylic acid . In contrast, para-aminobenzoic acid, a folate precursor in bacteria, was poorly acetylated . Of the wild-type strains studied, Pseudomonas aeruginosa was the best acetylator in terms of both substrate spectrum and catalytic efficiency . DNA hybridization with a Salmonella enterica serovar Typhimurium-derived probe suggested the presence of this enzyme in eight proteobacterial and four gram-positive species . Molecular aspects together with the kinetic data suggest distinct functional features for this class of microbial enzymes. Microbes Infect, 2001 Apr, 3(4), 333 - 40 Molecular pathogenesis of Citrobacter rodentium and transmissible murine colonic hyperplasia; Luperchio SA et al.; Here we review the history, clinical significance, pathology and molecular pathogenesis of Citrobacter rodentium, the causative agent of transmissible murine colonic hyperplasia . C . rodentium serves as an important model pathogen for investigating the mechanisms controlling attaching and effacing pathology, epithelial hyperproliferation, and tumor promotion in the distal colon of the mouse. J Appl Microbiol, 2001 Apr, 90(4), 543 - 9 Development of a monoclonal sandwich ELISA for the detection of animal and human Escherichia coli O157 strains; Kerr P et al.; AIMS: Production of a monoclonal antibody (MAb) to Escherichia coli O157 to develop a rapid test using a sandwich ELISA (sELISA) format . METHODS AND RESULTS: A MAb (7A6) was developed to the long-chain lipopolysaccharide of E . coli O157 . A sELISA developed with the MAb reacted with 28 bovine and seven human enterohaemorrhagic E . coli (EHEC) O157 strains and also with two enterotoxigenic E . coli O157 strains . Cross-reaction to a rabbit diarrhoeal E.coli O15, Citrobacter freundii, Salmonella urbana and Vibrio cholerae O1 Inaba was detected . CONCLUSION: A MAb-based sELISA to detect E . coli O157 was produced . Its application to field samples is required to fully determine its prospective use for the detection of EHEC O157, to evaluate the non-specific interference of the cross-reacting strains . SIGNIFICANCE AND IMPACT OF THE STUDY: The assay produced is not wholly specific to EHEC O157, but has the potential to be used as a rapid method for screening large numbers of samples for E . coli O157. Pediatr Infect Dis J, 2001 Mar, 20(3), 331 - 6 Cefepime microbiologic profile and update; Kessler RE; BACKGROUND: The evolution of the cephalosporin class of antibiotics through modifications of the basic cephem structure has resulted in a new generation with improved antibacterial activity . Cefepime is a prototypic agent of this new class of fourth generation cephalosporins . OBJECTIVE: To review the microbiologic profile of cefepime . RESULTS: Cefepime, which is a zwitterion, has a net neutral charge that allows it to penetrate the outer membrane of Gram-negative bacteria faster than third generation cephalosporins . It is more stable against beta-lactamases because of the lower affinity of the enzymes for cefepime when compared with third generation cephalosporins . As a result of these structural attributes, cefepime has in vitro activity against pathogens that are prevalent in pediatric infections . This agent offers the advantage of Gram-positive coverage similar to that of cefotaxime and ceftriaxone, as well as good activity against Pseudomonas aeruginosa and many enteric bacilli that are resistant to third generation cephalosporins, including clinical isolates of Enterobacter spp . and Citrobacter freundii . CONCLUSIONS: Based on its spectrum of activity cefepime is an option for the treatment of pediatric infections caused by susceptible pathogens. Eur J Biochem, 2001 Apr, 268(8), 2369 - 78 Identification and expression of the genes and purification and characterization of the gene products involved in reactivation of coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii; Seifert C et al.; The coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii is subject to suicide inactivation by the natural substrate glycerol during catalysis . We identified dhaF and dhaG as the genes responsible for reactivation of inactivated dehydratase . Northern blot analyses revealed that both genes were expressed during glycerol fermentation . The dhaF gene is transcribed together with the three structural genes coding for glycerol dehydratase (dhaBCE), whereas dhaG is coexpressed with the dhaT gene encoding 1,3-propanediol dehydrogenase . The dhaF and dhaG gene products were copurified to homogeneity from cell-free extracts of a recombinant E . coli strain producing both His6-tagged proteins . Both proteins formed a tight complex with an apparent molecular mass of 150 000 Da . The subunit structure of the native complex is probably alpha2beta2 . The factor rapidly reactivated glycerol- or O2-inactivated hologlycerol dehydratase and activated the enzyme-cyanocobalamin complex in the presence of coenzyme B12, ATP, and Mg2+ . The DhaF-DhaG complex and DhaF exhibited ATP-hydrolyzing activity, which was not directly linked to the reactivation of dehydratase . The purified DhaF-DhaG complex of C . freundii efficiently cross-activated the enzyme-cyanocobalamin complex and the glycerol-inactivated glycerol dehydratase of Klebsiella pneumoniae . It was not effective with respect to the glycerol dehydratase of Clostridium pasteurianum and to diol dehydratases of enteric bacteria. Int J Antimicrob Agents, 2001 Apr, 17(4), 253 - 8 Secretion of cytokines by uroepithelial cells stimulated by Escherichia coli and Citrobacter spp; Funfstuck R et al.; Urinary tract epithelial cells (T 24/83) are able to express interleukin (IL)-6, IL-8, platelet-derived growth factor (PDGF) and tumour necrosis factor-alpha, but not IL-1 beta, IL-2, IL-4 and IL-10 in response to an infection with uropathogenic bacteria . The process of cytokine secretion is time dependent, with a significant increase in the cytokine activity after 60 min . The expression of virulence factors of the bacteria does not seem to play a role . The interaction between bacterial products (e.g . lipopolysaccharide) and/or bacterial adhesion mediated by adhesins and specific receptor molecules of cell surfaces may be responsible for the activity of mediator protein expression in the epithelial cells . The release of PDGF and IL-8 was found to be higher when due to Escherichia coli HB 101 (rough form) than that caused by other bacterial strains . Citrobacter CB 3009 provoked the highest level of IL-6 . The PDGF level correlated significantly with IL-6 and IL-8 values (P<0.001) . There was a significant correlation between the time-dependent release of IL-6 and IL-8 (P<0.05) . In epithelial cytokine response to bacterial infection, the reaction of the epithelial cells may modify themselves (e.g . internalization of bacteria) and the immuno-regulatory processes that are caused by infection and responsible for parenchymal injury. Surg Endosc . 2000 Aug;14(8):767 . Epub 2000 Jul 12. Liver hematoma following endoscopic retrograde cholangiopancreatography (ERCP); Ortega Deballon P et al.; We report the case of an 81-year-old man who presented with abdominal pain following endoscopic retrograde cholangiopancreatography (ERCP) for choledocholithiasis . A diagnosis of infected hematoma was made . A CT-guided puncture produced bloody matter that grew Citrobacter freundii . A catheter was left in place for 3 weeks before the patient could be discharged from hospital . We hypothesize that the hepatic parenchyma had been torn by the guide used during the ERCP . This case represents the first report of this type of iatrogenic injury. Appl Environ Microbiol, 2001 Apr, 67(4), 1558 - 64 Identification and characterization of integron-mediated antibiotic resistance among Shiga toxin-producing Escherichia coli isolates; Zhao S et al.; A total of 50 isolates of Shiga toxin-producing Escherichia coli (STEC), including 29 O157:H7 and 21 non-O157 STEC strains, were analyzed for antimicrobial susceptibilities and the presence of class 1 integrons . Seventy-eight (n = 39) percent of the isolates exhibited resistance to two or more antimicrobial classes . Multiple resistance to streptomycin, sulfamethoxazole, and tetracycline was most often observed . Class 1 integrons were identified among nine STEC isolates, including serotypes O157:H7, O111:H11, O111:H8, O111:NM, O103:H2, O45:H2, O26:H11, and O5:NM . The majority of the amplified integron fragments were 1 kb in size with the exception of one E . coli O111:H8 isolate which possessed a 2-kb amplicon . DNA sequence analysis revealed that the integrons identified within the O111:H11, O111:NM, O45:H2, and O26:H11 isolates contained the aadA gene encoding resistance to streptomycin and spectinomycin . Integrons identified among the O157:H7 and O103:H2 isolates also possessed a similar aadA gene . However, DNA sequencing revealed only 86 and 88% homology, respectively . The 2-kb integron of the E . coli O111:H8 isolate contained three genes, dfrXII, aadA2, and a gene of unknown function, orfF, which were 86, 100, and 100% homologous, respectively, to previously reported gene cassettes identified in integrons found in Citrobacter freundii and Klebsiella pneumoniae . Furthermore, integrons identified among the O157:H7 and O111:NM strains were transferable via conjugation to another strain of E . coli O157:H7 and to several strains of Hafnia alvei . To our knowledge, this is the first report of integrons and antibiotic resistance gene cassettes in STEC, in particular E . coli O157:H7. J Laryngol Otol, 2001 Apr, 115(4), 327 - 9 Acute tonsillitis complicated by retropharyngeal and thyroid abscess infected with de-repressed beta lactamase Citrobacter mutans; Maini S et al.; An unusual presentation of acute tonsillitis complicated by retropharyngeal and thyroid abscess is reported . Spontaneous rupture of retropharyngeal abscess resulted in necrotic fistulae between the pharyngeal wall and the retropharyngeal space. J Biochem (Tokyo), 2001 Apr, 129(4), 607 - 13 A cryptic melibiose transporter gene possessing a frameshift from Citrobacter freundii; Shimamoto T et al.; Wild-type Citrobacter freundii cannot grow on melibiose as a sole source of carbon . The melibiose transporter gene melB was cloned from a C . freundii mutant M4 that could utilize melibiose as a sole carbon source . Although the cloned melB gene is closely similar to the melB genes of other bacteria, it is cryptic because of a frameshift mutation . Site-directed mutagenesis was used to construct a functional melB gene by deleting one nucleotide, resulting in the production of an active melibiose transporter . The active MelB transporter could utilize Na(+) and H(+) as coupling cations to melibiose transport . The amino acid sequence of the C . freundii MelB was found to be most similar to those of Salmonella typhimurium and Escherichia coli MelB . These facts are consistent with the phylogenetic relationship of bacteria and the cation coupling properties of the melibiose transporters. J Microbiol Immunol Infect, 2000 Dec, 33(4), 258 - 62 Comparison of antimicrobial susceptibility of Citrobacter freundii isolates in two different time periods; Wang JT et al.; Citrobacter freundii was first identified in 1932, since then it has been reported to cause a variety of infections in aged, immunocompromised, and debilitated patients . With the use of broad-spectrum antibiotics, C . freundii has become increasingly resistant to antimicrobial agents . In order to determine the chronological changes in susceptibility and current susceptibility status of C . freundii, we compared the antimicrobial susceptibility of C . freundii in two different time periods, from 1987 to 1988 and from 1997 to 1998 . In both time periods, 61 isolates of C . freundii were randomly selected for study from all clinical isolates at National Taiwan University Hospital . The minimum inhibitory concentrations and susceptible rates of 15 antimicrobial agents were compared, and it was found that most C . freundii isolates were resistant to anti-pseudomonal penicillins, first, second, and third generation cephalosporins, gentamicin, tobramycin, and aztreonam . The results indicate that the susceptible rates of C . freundii to aminoglycosides and ciprofloxacin decreased markedly during the period from 1987 to 1998 . Cefepime, cefpirome, imipenem, and meropenem remained the most active agents against C . freundii. Enferm Infecc Microbiol Clin, 2001 Jan, 19(1), 11 - 4 {Characterization and distribution of Citrobacter species in a university hospital}; Manganello S et al.; OBJETIVE: a) To identify Citrobacter strains following the conventional biochemical reaction of Brenner and col; b) to evaluate the sensitivity and specificity of the O'Hara's method compared with Brenner's method, and c) to determine the rate and distribution of the strains in the clinical isolates . MATERIAL AND METHODS: One hundred and twenty two clinical isolates, characterized as Citrobacter spp . were collected between May of 1994 and August of 1997 . Clinical isolates included inpatients and outpatients from Hospital de Clinicas . Strains were identified following the methods of Brenner and O'Hara . RESULTS: Methods of Brenner identified 111 of 122 strains: C . freundii 59 of 111; C . koseri 18 of 111; C . werkmanii 15 of 111; C . braakii 9 of 111; C . youngae 6 of 111 and C . amalonaticus 4 of 111 . O'Hara's methods identified 104 of 111 strains (94%) . C . freundii was recovered most frequently from urine and feces (p Fisher < 0.026 and 0.039 respectively), while C . koseri was isolated from urine principally (p Fisher < 0.0372) . CONCLUSIONS: The genus Citrobacter is an important opportunistic pathogen that can be identified in clinical microbiology laboratories using O'Hara's method. Jpn J Antibiot, 2000 Sep, 53(9), 593 - 608 {In vitro antibacterial activity of prulifloxacin, a new oral quinolone, and comparative susceptibility rate at clinical breakpoint MIC}; Inoue M et al.; In vitro drug sensitivity of clinically isolated bacteria against prulifloxacin (PUFX), which is a new quinolone, was investigated, and the antibacterial activity and susceptibility rate at clinical breakpoint were compared with those of norfloxacin, ofloxacin (OFLX), ciprofloxacin, tosufloxacin, fleroxacin, sparfloxacin and levofloxacin (LVFX) . The following results were obtained . 1) PUFX showed a broad-spectrum antibacterial activity against both Gram-positive and Gram-negative bacteria . 2) MIC80 of PUFX was 0.25 and 1 microgram/ml, against methicillin susceptible Staphylococcus aureus and Streptococcus pneumoniae, respectively and below 0.125 microgram/ml against Gram-negative Enterobacteriaceae . MIC90 of PUFX against Pseudomonas aeruginosa, which has MIC not exceeding 4 micrograms/ml to OFLX, was 0.5 microgram/ml . 3) PUFX was judged as active against the bacteria under the criteria proposed presented by "the Sensitivity Determination Committee for Antibiotics, Japan Society of Chemotherapy: Break Point for Respiratory Infectious Diseases and Sepsis" . It is suggested that the sensitivity of each bacterial species to PUFX was high . 4) From the correlation analysis of MIC, PUFX was shown to have two to eight times higher antibacterial acitivity than LVFX for Citrobacter freundii, Serratia marcescens and Pseudomonas aeruginosa . 5) PUFX showed potent short-time bactericidal activity against S . aureus and P . aeruginosa. Zh Mikrobiol Epidemiol Immunobiol, 2000 Nov-Dec, (6), 15 - 8 {Diagnostic value of a novel nutrient medium for isolation and cultivation of pathogens causing enteric yersiniosis and pseudotuberculosis}; Saiapina LV et al.; A new nutrient medium for isolation and cultivation of the causative agents of enteric yersiniosis and pseudotuberculosis was found to have advantages over Endo medium in its differentiating and inhibiting properties . This medium permitted the easy differentiation of Yersinia pseudotuberculosis from Y . enterocolitica, as well as from Escherichia coli, Shigella flexneri, Klebsiella pneumoniae, K . rhinoscleromatis, Hafnia, Enterobacter and Citrobacter by color; from Proteus inconstans by swarming . In addition, weakly swarming of P . vulgaris differed by their light bluish color and Pseudomonas aeruginosa, by the brilliance and size of colonies . Endo medium could be used only for differentiation of E . coli from lactose-negative Yersinia colonies, Klebsiella (by mucous growth) and, to a certain extent, all Proteus species (by swarming) . The medium under test and the control medium inhibited the growth of Staphylococcus aureus . In contrast to Endo medium, the medium under test partially inhibited the growth of K . rhinoscleromatis and the swarming of P . inconstans . The new medium is now introduced into practice. Am Surg, 2001 Jan, 67(1), 80 - 5 Splenic abscess: report of six cases and review of the literature; Green BT; Splenic abscesses are rare but appear to be increasing in frequency . Recent advances in radiologic techniques have affected the diagnosis and management . The purpose of this study was to evaluate these effects . The medical records of one institution were retrospectively reviewed and six cases of splenic abscesses seen between 1989 and 1999 were identified . All patients had predisposing conditions with metastatic hematogenous infection in three and one each with trauma, immunodeficiency, and a contiguous site of infection . Fever was present in all patients with chills and vomiting in five and three patients, respectively . Left upper quadrant tenderness appeared in four patients and leukocytosis was found in every patient except one with the acquired immunodeficiency syndrome . Chest roentgenograms were abnormal in five patients with a left pleural effusion most common . Ultrasound revealed the defect in both patients it was utilized in and computed tomography was diagnostic in all cases . The causative organisms were anaerobes in two cases and Candida albicans, Streptococcus viridans, Escherichia coli, and Citrobacter freundii each present in one case . Radiology guided percutaneous drainage was attempted in four patients but was only successful in one . Splenectomy with antibiotics was curative in the remainder with a 100 per cent survival . These data suggest that percutaneous drainage may be appropriate for certain patients initially, but the high failure rate demonstrates that splenectomy remains the standard treatment. Curr Microbiol, 2001 Apr, 42(4), 290 - 4 Isolation and identification of bacteria associated with adult laboratory Mexican fruit flies, Anastrepha ludens (Diptera: Tephritidae); Kuzina LV et al.; From the guts of new and old colonies (female and male) of Mexican fruit flies, Anastrepha ludens (Diptera: Tephritidae), we identified a total of 18 different bacterial species belonging to the family Enterobacteriaceae, Pseudomonadaceae, Vibrionaceae, Micrococcaceae, Deinococcacea, Bacillaceae, and the genus Listeria . Enterobacter, Providencia, Serratia, and Staphylococcus spp . were the most frequently isolated genera, with Citrobacter, Streptococcus, Aerococcus, and Listeria found less frequently . We found Bacillus cereus, Enterobacter sakazakii, Providencia stuartii, and Pseudomonas aeruginosa only in the new colony, Aeromonas hydrophila and Klebsiella pneumoniae spp . pneumoniae only in the old colony . We also studied resistance/sensitivity to 12 antibiotics for six bacterial isolates such as Enterobacter cloacae, E . sakazakii, K . pneumoniae spp., Providencia rettgeri, P . aeruginosa, and Bacillus cereus . Isolates on the whole were resistant to penicillin and ampicillin (five of six isolates) and sensitive to rifampin and streptomycin (six of six isolates) . Antibiotic resistance profiles might be useful characteristics for distinguishing among species and strains of these bacteria, probably having ecological significance with respect to intra- and inter-specific competition within host cadavers, and could have implications for the utility of these organisms for biological control, including the alternative control strategy, paratransgenesis. Microb Pathog, 2001 Jan, 30(1), 19 - 28 Bacterial invasion and transcytosis in transfected human brain microvascular endothelial cells; Stins MF et al.; Most cases of neonatal bacterial meningitis develop as a result of a hematogenous spread, but it is not clear how circulating bacteria cross the blood-brain barrier . Attempts to answer these questions have been hampered by the lack of a reliable model of the human blood-brain barrier . Human brain microvascular endothelial cells (HBMEC) were isolated and transfected with a pBR322 based plasmid containing simian virus 40 large T antigen (SV40-LT) . The transfected HBMEC exhibited similar brain endothelial cell characteristics as the primary HBMEC, i.e . gamma glutamyl transpeptidase and a high transendothelial electrical resistance . Escherischia coli and Citrobacter spp, two important Gram-negative bacilli causing neonatal meningitis, were found to transcytose across primary and transfected HBMEC, without affecting the integrity of the monolayer . In addition, E . coli and C . freundii invaded transfected HBMEC as shown previously with primary HBMEC . We conclude that E . coli and C . freundii are able to invade and transcytose HBMEC and these bacterial-HBMEC interactions are similar between primary and transfected HBMEC . Therefore, our transfected HBMEC should be useful for studying pathogenesis of CNS infections . Can J Microbiol, 1993 Sep, 39(9), 821 - 5 Use of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside for the isolation of beta-galactosidase-positive bacteria from municipal water supplies; Ley A et al.; A new medium, mX-Gal, has been developed for the membrane filter enumeration of beta-galactosidase-positive bacteria in municipal water supplies . mX-Gal medium contains the chromogenic beta-galactosidase substrate 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) . All Aeromonas, Citrobacter, and Enterobacter strains isolated from raw water on mX-Gal medium were beta-galactosidase positive . In contrast, only 10 to 20% of these strains produced a red colony with a metallic sheen on m-Endo agar LES medium . Of 674 chlorinated water samples analyzed for total coliforms on m-Endo agar LES medium and for beta-galactosidase-positive bacteria on mX-Gal medium, 18 that were negative for coliforms on m-Endo agar LES showed beta-galactosidase-positive bacteria on mX-Gal . Of a total of 50 beta-galactosidase-positive bacteria isolated from these samples, 76% were identified as Aeromonas hydrophila. Urology . 1999 Dec;54(6):1097. Citrobacter diversus urosepsis and cerebral abscess in a child with antenatal hydronephrosis; Ferrer FA et al.; One percent of all pregnancies are found to have an antenatal abnormality; of these, 20% involve the genitourinary system . Today, controversy still exists regarding the postnatal management of some antenatal abnormalities detected by ultrasound . We present a case in which antenatal hydronephrosis initially detected by ultrasound appeared to resolve in utero . Postnatally, the child developed Citrobacter diversus urosepsis, meningitis, and cerebral abscess . Voiding cystourethrogram obtained after resolution of sepsis revealed grade IV reflux . This case underscores the importance of a full postnatal evaluation for all children with antenatal hydronephrosis and alerts clinicians to a virulent pathogen not commonly associated with urinary tract infection. Am J Med Sci, 2000 Dec, 320(6), 408 - 10 Citrobacter diversus endocarditis; Tellez I et al.; Citrobacter species are motile Gram-negative bacilli that cause disease in humans, such as urinary tract infection, pneumonia, superficial and deep wound infections, gastroenteritis, meningitis, bacteremia, and rarely endocarditis . In those cases of endocarditis, intravenous drug use has been associated with Citrobacter species . Gram-negative organisms are present in less than 10% of cases of endocarditis in intravenous drug users . We present a case of tricuspid valve endocarditis in an intravenous drug user caused by Citrobacter diversus alone. Nucleic Acids Res, 2001 Jan 15, 29(2), 380 - 6 Conserved regulatory elements of the promoter sequence of the gene rpoH of enteric bacteria; Ramirez-Santos J et al.; The rpoH regulatory region of different members of the enteric bacteria family was sequenced or downloaded from GenBank and compared . In addition, the transcriptional start sites of rpoH of Yersinia frederiksenii and Proteus mirabilis, two distant members of this family, were determined . Sequences similar to the sigma(70) promoters P1, P4 and P5, to the sigma(E) promoter P3 and to boxes DnaA1, DnaA2, cAMP receptor protein (CRP) boxes CRP1, CRP2 and box CytR present in Escherichia coli K12, were identified in sequences of closely related bacteria such as: E.coli, Shigella flexneri, Salmonella enterica serovar Typhimurium, Citrobacter freundii, Enterobacter cloacae and Klebsiella pneumoniae . In more distant bacteria, Y.frederiksenii and P.mirabilis, the rpoH regulatory region has a distal P1-like sigma(70) promoter and two proximal promoters: a heat-induced sigma(E)-like promoter and a sigma(70) promoter . Sequences similar to the regulatory boxes were not identified in these bacteria . This study suggests that the general pattern of transcription of the rpoH gene in enteric bacteria includes a distal sigma(70) promoter, >200 nt upstream of the initiation codon, and two proximal promoters: a heat-induced sigma(E)-like promoter and a sigma(70) promoter . A second proximal sigma(70) promoter under catabolite-regulation is probably present only in bacteria closely related to E.coli. JAMA, 2000 Dec 27, 284(24), 3151 - 6 Emergence of domestically acquired ceftriaxone-resistant Salmonella infections associated with AmpC beta-lactamase; Dunne EF et al.; CONTEXT: Ceftriaxone, an expanded-spectrum cephalosporin, is an antimicrobial agent commonly used to treat severe Salmonella infections, especially in children . Ceftriaxone-resistant Salmonella infections have recently been reported in the United States, but the extent of the problem is unknown . OBJECTIVES: To summarize national surveillance data for ceftriaxone-resistant Salmonella infections in the United States and to describe mechanisms of resistance . DESIGN AND SETTING: Case series and laboratory evaluation of human isolates submitted to the Centers for Disease Control and Prevention from 17 state and community health departments participating in the National Antimicrobial Resistance Monitoring System (NARMS) for enteric bacteria between 1996 and 1998 . PATIENTS: Patients with ceftriaxone-resistant Salmonella infections between 1996 and 1998 were interviewed and isolates with decreased ceftriaxone susceptibility were further characterized . MAIN OUTCOME MEASURES: Exposures and illness outcomes, mechanisms of resistance . RESULTS: The prevalence of ceftriaxone-resistant Salmonella was 0.1% (1 of 1326) in 1996, 0.4% (5 of 1301) in 1997, and 0.5% (7 of 1466) in 1998 . Ten (77%) of the 13 patients with ceftriaxone-resistant infections were aged 18 years or younger . The patients lived in 8 states (California, Colorado, Kansas, Massachusetts, Maryland, Minnesota, New York, and Oregon) . Nine (82%) of 11 patients interviewed did not take antimicrobial agents and 10 (91%) did not travel outside the United States before illness onset . Twelve of the 15 Salmonella isolates with ceftriaxone minimum inhibitory concentrations of 16 microg/mL or higher were serotype Typhimurium but these isolates had different pulsed-field gel electrophoresis patterns . Thirteen of these 15 isolates collected between 1996 and 1998 were positive for a 631-base pair polymerase chain reaction product obtained by using primers specific for the ampC gene of Citrobacter freundii . CONCLUSIONS: Domestically acquired ceftriaxone-resistant Salmonella has emerged in the United States . Most ceftriaxone-resistant Salmonella isolates had similar AmpC plasmid-mediated resistance. Int Microbiol, 1999 Sep, 2(3), 161 - 7 The Yersinia high-pathogenicity island; Carniel E; A pathogenicity island present only in highly pathogenic strains of Yersinia (Y . enterocolitica 1B, Y . pseudotuberculosis I and Y . pestis) has been identified on the chromosome of Yersinia spp . and has been designated High-Pathogenicity Island (HPI) . The Yersinia HPI carries a cluster of genes involved in the biosynthesis, transport and regulation of the siderophore yersiniabactin . The major function of this island is thus to acquire iron molecules essential for in vivo bacterial growth and dissemination . The presence of an integrase gene and att sites homologous to those of phage P4, together with a G + C content much higher than the chromosomal background, suggests that the HPI is of foreign origin and has been acquired by chromosomal integration of a phage . The HPI can excise from the chromosome of Y . pseudotuberculosis and is found inserted into any of the three copies of the asn tRNA loci present in this species . A unique characteristic of the HPI is its wide distribution in various enterobacteria . Although first identified in Yersinia spp., it has subsequently been detected in other genera such as E . coli, Klebsiella and Citrobacter. J Clin Microbiol, 2000 Dec, 38(12), 4586 - 92 Cost-effective and rapid presumptive identification of gram-negative bacilli in routine urine, pus, and stool cultures: evaluation of the use of CHROMagar orientation medium in conjunction with simple biochemical tests; Ohkusu K; The algorithm for a new identification system was designed on the basis of colony color and morphology on CHROMagar Orientation medium in conjunction with simple biochemical tests such as indole (IND), lysine decarboxylase (LDC), and ornithine decarboxylase (ODC) utilization tests with gram-negative bacilli isolated from urine samples as well as pus, stool, and other clinical specimens by the following colony characteristics, biochemical reactions, and serological results: pinkish to red, IND positive (IND(+)), Escherichia coli; metallic blue, IND(+), LDC(+), and ODC negative (ODC(-)), Klebsiella oxytoca; IND(+), LDC(-), and ODC(+), Citrobacter diversus; IND(+) or IND(-), LDC(-), and ODC(-), Citrobacter freundii; IND(-), LDC(+), and ODC(+), Enterobacter aerogenes; IND(-), LDC(-), and ODC(+), Enterobacter cloacae; IND(-), LDC(+), and ODC(-), Klebsiella pneumoniae; diffuse brown and IND(+), Morganella morganii; IND(-), Proteus mirabilis; aqua blue, Serratia marcescens; bluish green and IND(+), Proteus vulgaris; transparent yellow-green, serology positive, Pseudomonas aeruginosa; clear and serology positive, Salmonella sp.; other colors and reactions, the organism was identified by the full identification methods . The accuracy and cost-effectiveness of this new system were prospectively evaluated . During an 8-month period, a total of 345 specimens yielded one or more gram-negative bacilli . A total of 472 gram-negative bacillus isolates were detected on CHROMagar Orientation medium . For 466 of the isolates (98.7%), no discrepancies in the results were obtained on the basis of the identification algorithm . The cost of identification of gram-negative bacilli during this period was reduced by about 70% . The results of this trial for the differentiation of the most commonly encountered gram-negative pathogens in clinical specimens with the new algorithm were favourable in that it permitted reliable detection and presumptive identification . In addition, this rapid identification system not only significantly reduced costs but it also improved the daily work flow within the clinical microbiology laboratory. J Clin Microbiol, 2000 Dec, 38(12), 4343 - 50 Citrobacter rodentium, the causative agent of transmissible murine colonic hyperplasia, exhibits clonality: synonymy of C . rodentium and mouse-pathogenic Escherichia coli; Luperchio SA et al.; Citrobacter rodentium (formerly Citrobacter freundii biotype 4280 and Citrobacter genomospecies 9) was described on the basis of biochemical characterization and DNA-DNA hybridization data and is the only Citrobacter species known to possess virulence factors homologous to those of the human pathogens enteropathogenic Escherichia coli and enterohemorrhagic E . coli . These virulence factors are encoded on the locus of enterocyte effacement (LEE), a pathogenicity island required for the characteristic attaching and effacing (AE) pathology seen in infection with these three pathogens . C . rodentium, which apparently infects only mice, provides a useful animal model for studying the molecular basis of AE pathology . No work has been done to assess differences in pathogenicity between C . rodentium isolates from diverse sources . Here, we report the examination of 15 C . rodentium isolates using a battery of genetic and biochemical approaches . No differences were observed between the isolates by repetitive-element sequence-based PCR analysis, biochemical analysis, and possession of LEE-specific virulence factors . These data suggest that members of the species are clonal . We further characterized an atypical E . coli strain from Japan called mouse-pathogenic E . coli (MPEC) that, in our hands, caused the same disease as C . rodentium . Applying the same battery of tests, we found that MPEC possesses LEE-encoded virulence factors and is indistinguishable from the previously characterized C . rodentium isolate DBS100 . These results demonstrate that MPEC is a misclassified C . rodentium isolate and that members of this species are clonal and represent the only known attaching and effacing bacterial pathogen of mice. Antimicrob Agents Chemother, 2000 Dec, 44(12), 3478 - 80 Levofloxacin pharmacokinetics and serum bactericidal activities against five enterobacterial species; Geerdes-Fenge HF et al.; After oral administration of 500 mg of levofloxacin to 12 volunteers, we investigated the pharmacokinetics and serum bactericidal activities (SBAs) against five strains of members of the family Enterobacteriaceae . Pharmacokinetic data were as follows: maximum concentration in serum, 6.36 +/- 0.57 mg/liter; area under the concentration-time curve, 43.6 +/- 6.23 mg . h/liter; elimination half-life 4.23 +/- 0.87 h . SBAs were present for 24 h against Escherichia coli and Citrobacter freundii . The SBAs at 1, 12, and 24 h after administration against E . coli were 1:108, 1:29, and 1:7, respectively, and those against Citrobacter freundii were 1:74, 1:25, and 1:7, respectively . The SBAs were present for 12 h against the other three organisms tested . The SBAs against Serratia marcescens were 1:28 and 1:9 at 1 and 12 h, respectively; the SBAs against Klebsiella pneumoniae were 1:25 and 1:7 at 1 and 12 h, respectively; and the SBAs against Enterobacter cloacae were 1:24 and 1:10 at 1 and 12 h, respectively. Expert Opin Investig Drugs, 2000 Aug, 9(8), 1877 - 95 Gatifloxacin: a new fluoroquinolone; Blondeau JM; Gatifloxacin is a new 8-methoxy-fluoroquinoline antimicrobial agent . It has enhanced activity against Gram-positive and atypical agents, while retaining broad-spectrum antiGram-negative activity . For example, the MIC(90) values for respiratory tract pathogens are < or = 0.5 microg/ml for organisms such as Streptococcus pneumoniae (regardless of penicillin susceptibility), Haemophilus influenzae (beta-lactamase positive or negative), Moraxella catarrhalis (beta-lactamase positive or negative), Legionella species, Mycoplasma pneumoniae, methicillin-sensitive Staphylococcus aureus, beta-haemolytic Streptococci (macrolide sensitive or resistant), Neisseria species, most Enterobacteriaceae, Neisseria gonorrhoeae, Neisseria meningitidis, Pasteurella species, Vibrio species and Yersinia enterocolitica . For methicillin-resistant S . aureus, ciprofloxacin-resistant S . aureus, Citrobacter freundii, Providencia species, Serratia species, Pseudomonas aeruginosa and other non-fermentative Gram-negative bacilli, the MIC(90) are elevated . Gatifloxacin is bactericidal and exhibits a post-antibiotic effect against Gram-positive and -negative bacteria . The standard dose is 400 mg once daily and is available in both oral and iv . formulation . Gatifloxacin appears to have a low propensity for the selection of resistant mutants . Clinical trial data supports the use of gatifloxacin for treatment of patients with respiratory tract, urinary tract, skin and soft tissue infections . The side effect profile for gatifloxacin is similar to that with other agents. J Clin Microbiol, 2000 Nov, 38(11), 3946 - 52 Outbreak of nosocomial infections due to extended-spectrum beta-lactamase-producing strains of enteric group 137, a new member of the family Enterobacteriaceae closely related to Citrobacter farmeri and Citrobacter amalonaticus; Warren JR et al.; A member of the Enterobacteriaceae initially identified as Kluyvera cryocrescens by the MicroScan Gram-Negative Combo 13 panel caused an outbreak of nosocomial infections in four patients (pneumonia, n = 2; urinary tract infection, n = 1; wound infection, n = 1) and urinary tract colonization in one patient . When the strains were tested by the Enteric Reference Laboratory of the Centers for Disease Control and Prevention, biochemical results were most compatible with Yersinia intermedia, Kluyvera cryocrescens, and Citrobacter farmeri but identification scores were low and test results were discrepant . However, when the biochemical test profile was placed in the computer database as a new organism, all strains were identified as the organism with high identification scores (0 . 999968 to 0.999997) and no discrepant test results . By 16S rRNA sequence analysis the organism clustered most closely with, but was distinct from, Citrobacter farmeri and Citrobacter amalonaticus . Based on its unique biochemical profile and rRNA sequence, this organism is designated Enteric Group 137 . Restriction endonuclease analysis and taxonomic antibiograms of strains causing the outbreak demonstrated a single clone of Enteric Group 137, and antibiotic susceptibility testing revealed the presence of extended-spectrum beta-lactamase (ESBL) resistance . Enteric Group 137 appears to be a new opportunistic pathogen that can serve as a source of ESBL resistance in the hospital. J Endotoxin Res, 2000, 6(3), 205 - 14 Enteric bacteria, lipopolysaccharides and related cytokines in inflammatory bowel disease: biological and clinical significance; Caradonna L et al.; Ulcerative colitis (UC) and Crohn's disease (CD) {inflammatory bowel disease (IBD)} are both characterized by an exaggerated immune response at the gut associated lymphoreticular tissue level . Such an abnormal and dysregulated immune response may be directed against luminal and/or enteric bacterial antigens, as also supported by murine models of inflammatory bowel disease (IBD) caused by organisms such as Citrobacter rodentium and Helicobacter hepaticus . Bacterial endotoxins or lipopolysaccharides (LPS) have been detected in the plasma of IBD patients and an abnormal microflora and/or an increased permeability of the intestinal mucosa have been invoked as cofactors responsible for endotoxemia . At the same time, the evidence that phagocytosis and killing exerted by polymorphonuclear cells and monocytes and the T-cell dependent antibacterial activity are decreased in IBD patients may also explain the origin of LPS in these diseases . In IBD, pro-inflammatory cytokines and chemokines have been detected in elevated amounts in mucosal tissue and/or in peripheral blood, thus suggesting a monocyte/macrophage stimulation by enteric bacteria and/or their constituents (e.g . LPS) . On these grounds, in experimental models and in human IBD, anti-cytokine monoclonal antibodies and interleukin receptor antagonists are under investigation for their capacity to neutralize the noxious effects of immune mediators . Finally, the administration of lactobacilli is beneficial in human IBD and, in murine colitis, this treatment leads to a normalization of intestinal flora, reducing the number of colonic mucosal adherent and translocated bacteria. FEMS Microbiol Ecol, 2000 Oct 1, 34(1), 81 - 90 Detection and distribution of insertion sequence 1 (IS1)-containing bacteria in the freshwater environment(1); Rhodes G et al.; The distribution of insertion sequence 1 (IS1)-containing bacteria was investigated in Windermere (Cumbria, UK), a freshwater body impacted by treated sewage discharge and run-off from the surrounding catchment . Culturable IS1-containing bacteria were recovered from the water column at three depths in Windermere North Basin (WNB) and South Basin (WSB), and from sediment at both sites (at the sediment surface in WSB and to a depth of 12-13 cm in WNB) . Polymerase chain reaction amplification of IS1 and the Escherichia coli/Shigella sp . specific gene uidA, from community DNA from shallow sediments, extended the detection limit beyond that of culture at both sites . This detection was extended further into deep sediment extracted from WNB as IS1 and uidA were detected in sub-samples to a depth of 4.7 and 2.3 m, respectively . Analysis of a representative subset of 90 IS1-carrying isolates recovered from water and sediment at both sites demonstrated 21 heterogeneous IS1 profiles with estimated copy numbers ranging from 1 to 16 . Identification of the host bacteria showed that the element was confined mainly to Enterobacter spp . However, this study showed IS1 to be present in Citrobacter freundii for the first time . Plasmids were carried by 75.3% of enterobacterial isolates and four plasmids (2.6%) carried IS1 . DNA sequence analysis of five IS1 clones demonstrated that IS1 isoforms from this study were similar (>89% nucleotide identity) to known IS1 isoforms . Two isoforms of IS1 from a single Enterobacter cloacae isolate differed by 6.7% at the nucleotide level suggesting that they had been acquired independently. Antimicrob Agents Chemother, 2000 Nov, 44(11), 3137 - 43 Biological cost of AmpC production for Salmonella enterica serotype Typhimurium; Morosini MI et al.; Chromosomally mediated AmpC-type beta-lactamases are frequently found among Enterobacteriaceae . Hyperproduction of AmpC beta-lactamase results in high-level resistance to beta-lactam antibiotics . One striking feature of Salmonella is the absence of the structural ampC gene, encoding AmpC beta-lactamase, in contrast with other members in the Enterobacteriaceae family, such as Escherichia, Citrobacter, or Enterobacter . The horizontal acquisition of ampC genes is one of the causes of the increased resistance to extended-spectrum cephalosporins and beta-lactamase inhibitors among gram-negative rods . Nevertheless, despite the high number of beta-lactam-resistant Salmonella isolates so far described, only two strains expressing resistance to cephalosporin and beta-lactamase inhibitors which is mediated by AmpC-type enzymes have been found . In this work, data are provided which support the possibility that the maintenance and expression of the ampC gene may represent an unbearable cost for Salmonella in terms of reduction of some of its lifestyle attributes, such as growth rate and invasiveness . The deleterious AmpC burden can be eliminated by decreasing the production of AmpC when both the regulatory gene, ampR, and ampC are present in Salmonella . Thus, it is suggested that the two genes have to be acquired together by Salmonella, leading to an inducible beta-lactam resistance phenotype . AmpC synthesis did not produce major variations in the peptidoglycan composition of Salmonella. Microbes Infect, 2000 Aug, 2(10), 1237 - 44 Bacterial penetration across the blood-brain barrier during the development of neonatal meningitis; Huang SH et al.; Bacterial pathogens may breach the blood-brain barrier (BBB) and invade the central nervous system through paracellular and/or transcellular mechanisms . Transcellular penetration, e.g., transcytosis across the BBB has been demonstrated for Escherichia coli K1, group B streptococcus, Listeria monocytogenes, Citrobacter freundii and Streptococcus pneumonia strains . Genes contributing to invasion of brain microvascular endothelial cells include E . coli K1 genes ompA, ibeA, ibeB, and yijP . Understanding the mechanisms of bacterial penetration across the BBB may help develop novel approaches to preventing bacterial meningitis. Nucleic Acids Res, 2000 Oct 1, 28(19), 3817 - 22 DNA methylation at the CfrBI site is involved in expression control in the CfrBI restriction-modification system; Beletskaya IV et al.; We have previously found that genes of the CFR:BI restriction-modification (R-M) system from Citrobacter freundii are oriented divergently and that their promoter regions overlap . The overlapping promoters suggest regulation of gene expression at the transcriptional level . In this study the transcription regulation of CFR:BI R-M genes was analyzed in vivo and in vitro in Escherichia coli . It was shown that in the presence of CFR:BI methyltransferase (M.CFR:BI), cell galactokinase activity decreases 10-fold when the galactokinase gene (galK) is under the control of the cfrBIM promoter and increases 20-fold when galK is under the control of the cfrBIR promoter . The CFR:BI site, proven to be unique for the entire CFR:BI R-M gene sequence, is located in the -35 cfrBIM promoter region and is in close vicinity of the -10 cfrBIR promoter region . A comparison of the cfrBIM and the cfrBIR promoter activities in the in vitro transcription system using methylated and unmethylated DNA fragments as templates demonstrated that the efficiency of CFR:BI R-M gene transcription is regulated by enzymatic modification at the N-4-position of cytosine bases of the CFR:BI site by M.CFR:BI . From the results of the in vivo and in vitro experiments we suggest a new model of gene expression regulation in type II R-M systems. J Food Prot, 2000 Sep, 63(9), 1273 - 6 Microbial evaluation of Spanish potato omelette and cooked meat samples in University restaurants; Soriano JM et al.; The focus of this study was to evaluate the microbial quality of Spanish potato omelette and cooked meat samples including pork loin, chicken croquettes, long pork sausage, chicken breast, and meatballs from University restaurants . Microbiological analyses of Spanish potato omelette and cooked meat samples resulted in aerobic plate counts from <1.00 to 2.90 and from <1.00 to 6.04 log10 CFU g(-1), respectively . Total coliforms ranged from <3 to 43 most probable number (MPN) g(-1) and from <3 to >2,400 MPN g(-1) for Spanish potato omelette and meat products, respectively . Escherichia coli, coagulase-positive staphylococci, and Lancefield group-D streptococci were detected in 1.7%, 3.5%, and 12.9% of Spanish potato omelette samples, respectively . For cooked meat samples, 8.8%, 7.6%, and 24.6% contained E . coli, coagulase-positive staphylococci, and Lancefield group-D streptococci, respectively . E . coli O157:H7, Salmonella spp., and Shigella spp . were not detected . Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter freundii, Enterobacter cloacae, and Serratia spp . were isolated from Spanish potato omelette samples . For cooked meat samples, C . freundii, E . cloacae, and Aeromonas hydrophila were detected . The results suggest that some handling practices should require more attention, and as a consequence, a hazard analysis and critical control point program should be developed and implemented. FEMS Microbiol Lett, 2000 Sep 1, 190(1), 157 - 61 Serological cross-reaction between the lipopolysaccharide O-polysaccharaide antigens of Escherichia coli O157:H7 and strains of Citrobcter freundii and Citrobacter sedlakii; Vinogradov E et al.; A strain of Citrobacter sedlakii showing serological cross-reaction with Escherichia coli O157 antisera was demonstrated to produce a lipopolysaccharide O-antigen having an identical structure with that of the E . coli O157 O-antigen . A strain of Citrobacter freunndii showing similar cross-reaction with E . coli O157 specific monoclonal antibody was shown to produce a lipopolysaccharide O-antigen composed of a trisaccharide repeating unit having the structure { 2)-alpha-D Rhap-(1-3)-beta-D-Rhap-(1-4)-beta-D-Glcp-(1-} . This O-antigen differs from that of the E . coli O157 O-antigen and also lacks a component 2-substituted 4-amino-4,6-dideoxy-alpha-D-mannopyranosyl residue implicated as the common epitope in the lipopolysaccharide O-antigens of previously investigated bacterial species showing serological cross-reactivity with E . coli O157 antisera . The C freundii O-antigen presents an interesting example of structural mimicry within a bacterial polysaccharide antigen. J Infect Dis, 2000 Oct, 182(4), 1268 - 71 Epub 2000 Sep 05. High-pathogenicity island of Yersinia pestis in enterobacteriaceae isolated from blood cultures and urine samples: prevalence and functional expression; Schubert S et al.; Production of the siderophore yersiniabactin is associated with virulence in Yersinia species . The genes for biosynthesis and uptake of yersiniabactin are located on a high-pathogenicity island (HPI) . The distribution and functioning of the Yersinia HPI were assessed in different Enterobacteriaceae strains isolated from blood cultures and urine samples . In total, 550 clinical isolates from 10 Enterobacteriaceae species were investigated by polymerase chain reaction and DNA hybridization . The Yersinia HPI was most prevalent in Escherichia coli (overall prevalence, 72.3%) and, to a lesser extent, in Klebsiella oxytoca (58.3%), Citrobacter species (25%), Klebsiella pneumonia (17.7%), and Enterobacter species (12.2%) . The production of the siderophore yersiniabactin was also demonstrated in these HPI-positive strains by use of a reporter gene bioassay . These findings indicate that the HPI of Yersinia is distributed and functions in clinical specimens of different Enterobacteriaceae species. Arq Neuropsiquiatr, 2000 Sep, 58(3A), 736 - 40 Brain abscess by citrobacter diversus in infancy: case report; Feferbaum R et al.; Citrobacter diversus is closely related to brain abscess in newborn infants . We describe a case of brain abscess by this bacteria in a newborn infant and his clinical and cranial computed tomographic evaluation until the fourth month of life and discuss therapeutic management of this patient. Lett Appl Microbiol, 2000 Aug, 31(2), 169 - 73 The capacity of Enterobacteriaceae species to produce biogenic amines in cheese; Marino M et al.; The amino acid decarboxylating activity and production of biogenic amines by 104 cheese-associated Enterobacteriaceae species (58 Enterobacter, 18 Serratia, eight Escherichia, seven Hafnia, six Arizona, four Citrobacter and three Klebsiella) were investigated . All strains could decarboxylate at least two amino acids in Moller's broth and in Niven's medium, and the decarboxylase activity was strain specific . In a laboratory medium containing all free amino acids, all strains could produce more than 100 ppm cadaverine, putrescine was produced by 96% of strains . Tyramine and histamine were produced in the lowest concentrations . A positive correlation existed between cadaverine concentration and Enterobacteriaceae counts in cheese, that may have caused the increase in decarboxylase content . This study suggests that it is possible to limit the presence of cadaverine in cheese, thereby controlling the Enterobacteriaceae counts, a sign of contamination during cheese making and/or storage. Appl Environ Microbiol, 2000 Sep, 66(9), 4131 - 5 Rapid 5' nuclease (TaqMan) assay for detection of virulent strains of Yersinia enterocolitica; Vishnubhatla A et al.; We have developed a rapid procedure for the detection of virulent Yersinia enterocolitica in ground pork by combining a previously described PCR with fluorescent dye technologies . The detection method, known as the fluorogenic 5' nuclease assay (TaqMan), produces results by measuring the fluorescence produced during PCR amplification, requiring no post-PCR processing . The specificity of the chromosomal yst gene-based assay was tested with 28 bacterial isolates that included 7 pathogenic and 7 nonpathogenic serotypes of Y . enterocolitica, other species of Yersinia (Y . aldovae, Y . pseudotuberculosis, Y . mollaretti, Y . intermedia, Y . bercovieri, Y . ruckeri, Y . frederiksenii, and Y . kristensenii), and other enteric bacteria (Escherichia, Salmonella, Citrobacter, and Flavobacterium) . The assay was 100% specific in identifying the pathogenic strains of Y . enterocolitica . The sensitivity of the assay was found to be >/=10(2) CFU/ml in pure cultures and >/=10(3) CFU/g in spiked ground pork samples . Results of the assay with food enrichments prespiked with Y . enterocolitica serotypes O:3 and O:9 were comparable to standard culture results . Of the 100 field samples (ground pork) tested, 35 were positive for virulent Y . enterocolitica with both 5' nuclease assay and conventional virulence tests . After overnight enrichment the entire assay, including DNA extraction, amplification, and detection, could be completed within 5 h. Infection, 2000 Jul-Aug, 28(4), 243 - 5 CSF interleukin-6 in neonatal Citrobacter ventriculitis after meningitis; Baumeister FA et al.; An infant with neonatal severe Citrobacter koseri (formerly Citrobacter diversus) meningoencephalitis developed necrosis with multicystic regression of both hemispheres . The ventriculitis persisted over months in spite of antibiotic therapy.The treatment succeeded with cefotaxime in a high dose (300 mg/kg/day) without surgical intervention.The infant had been previously treated with cefotaxime (200 mg/kg/day) over 5 weeks . High levels of CSF interleukin-6 (IL-6) permitted to attribute persisting CSF pleocytosis in spite of sterile CSF cultures to chronic infection and not to reminiscence of brain necrosis . This report reveals two main points . On the one hand, the importance of therapy monitoring with IL-6 in CSF for the consequent treatment of Citrobacter meningitis and on the other hand, high-dose cefotaxime (300 mg/kg/day) treatment of Citrobacter ventriculitis, which succeeded without surgical intervention. Pathol Biol (Paris), 2000 Jun, 48(5), 485 - 9 {Antibiotic sensitivity of enterobacteria in intensive care units}; Pina P et al.; Antibiotic therapy of intensive care patients is usually undocumented . The treatment is chosen according to epidemiologic and susceptibility data from microbiological laboratories . The aim of our study is to determine antibiotic susceptibility of enterobacteria isolated from intensive care patients during a five-month multicenter study in 18 French hospitals . Numerous (n = 1,113) strains were studied: 447 enterobacteria isolated from urine (n = 229), blood cultures (n = 106), respiratory tract specimens (n = 72), peritoneal fluids (n = 22), pus (n = 15) and catheters (n = 2) . MICs of group 2 and group 3 enterobacteria were determined using the dilution agar method and were interpreted according to the CASFM (Comite de l'antibiogramme de la societe francaise de microbiology) recommendations . Group 1 enterobacteria were most frequently isolated (67%) . Only one Escherichia coli strain produced ESBL (0.3%) . Among group 2 enterobacteria, one Citrobacter koseri strain produced ESBL . We did not isolate Klebsiella pneumoniae ESBL . Isolation of group 3 enterobacteria was frequent (24%) . Thirty-five percent of group 3 enterobacteria were resistant to cefotaxime, 26% to ceftazidime and 16% to cefepime and cefpirome . Fourteen strains of this group produced ESBL: 13 Enterobacter aerogenes and one E . amnigenus. Infect Immun, 2000 Sep, 68(9), 5120 - 5 Enhancement of neonatal innate defense: effects of adding an N-terminal recombinant fragment of bactericidal/permeability-increasing protein on growth and tumor necrosis factor-inducing activity of gram-negative bacteria tested in neonatal cord blood ex vivo; Levy O et al.; Innate defense against microbial infection requires the action of neutrophils, which have cytoplasmic granules replete with antibiotic proteins and peptides . Bactericidal/permeability-increasing protein (BPI) is found in the primary granules of adult neutrophils, has a high affinity for lipopolysaccharides (or "endotoxins"), and exerts selective cytotoxic, antiendotoxic, and opsonic activity against gram-negative bacteria . We have previously reported that neutrophils derived from newborn cord blood are deficient in BPI (O . Levy et al., Pediatrics 104:1327-1333, 1999) . The relative deficiency in BPI of newborns raised the possibility that supplementing the levels of BPI in plasma might enhance newborn antibacterial defense . Here we determined the effects of addition of recombinant 21-kDa N-terminal BPI fragment (rBPI(21)) on the growth and tumor necrosis factor (TNF)-inducing activity of representative gram-negative clinical isolates . Bacteria were tested in citrated newborn cord blood or adult peripheral blood . Bacterial viability was assessed by plating assay, and TNF-alpha release was measured by enzyme-linked immunosorbent assay . Whereas adult blood limited the growth of all isolates except Klebsiella pneumoniae, cord blood also allowed logarithmic growth of Escherichia coli K1/r and Citrobacter koseri . Bacteria varied in their susceptibility to rBPI(21)'s bactericidal action: E . coli K1/r was relatively susceptible (50% inhibitory concentration {IC(50)}, approximately 10 nM), C . koseri was intermediate (IC(50), approximately 1,000 nM), Klebsiella pneumoniae was resistant (IC(50), approximately 10,000 nM), and Enterobacter cloacae and Serratia marcescens were highly resistant (IC(50), >10,000 nM) . All isolates were potent inducers of TNF-alpha activity in both adult and newborn cord blood . In contrast to its variable antibacterial activity, rBPI(21) consistently inhibited the TNF-inducing activity of all strains tested (IC(50), 1 to 1,000 nM) . The antibacterial effects of rBPI(21) were additive with those of a combination of conventional antibiotics typically used to treat bacteremic newborns (ampicillin and gentamicin) . Whereas ampicillin and gentamicin demonstrated little inhibition of bacterially induced TNF release, addition of rBPI(21) either alone or together with ampicillin and gentamicin profoundly inhibited release of this cytokine . Thus, supplementing newborn cord blood with rBPI(21) potently inhibited the TNF-inducing activity of a variety of gram-negative bacterial clinical pathogens and, in some cases, enhanced bactericidal activity . These results suggest that administration of rBPI(21) may be of clinical benefit to neonates suffering from gram-negative bacterial infection and/or endotoxemia. Enzyme Microb Technol, 2000 Sep 1, 27(6), 399 - 405 Purification and characterization of the 1-3-propanediol dehydrogenase of Clostridium butyricum E5; Malaoui H et al.; 1-3 PPD dehydrogenase (EC 1.1.1.202) was purified to homogeneity from Clostridium butyricum E5 grown anaerobically on glycerol in continuous culture . The native enzyme was estimated by gel filtration to have a molecular weight of 384 200 +/- 31 100 Da; it is predicted to exist as an octamer or a decamer of identical molecular weight subunits . When tested as a dehydrogenase, the enzyme was most active with 1-3 propane diol . In the physiological direction, 3-hydroxypropionaldehyde was the preferred substrate . The apparent K(m) values of the enzyme for 3-hydroxypropionaldehyde and NADH were 0.17 mM and 0.06 mM, respectively . The enzyme requires only Mn(2+) for full activity . The enzyme was found to have properties similar to those reported for Klebsellia pneumoniae, Citrobacter freundii, and Clostridium pasteurianum. J Mol Microbiol Biotechnol, 2000 Jul, 2(3), 277 - 81 Prediction of two- and three-amino-acid sequences of Citrobacter Freundii beta-lactamase from its amino acid composition; Wu G et al.; The repeated amino-acid sequences in Citrobacter Freundii beta-lactamase may be indispensable for its function, because such repetitions cannot be simply attributed to a chance . In order to fully explore the functional units in Citrobacter Freundii beta-lactamase, it may need to analyse all the amino acid pairs, triplets, etc . along Citrobacter Freundii beta-lactamase from one terminal to the other terminal, to count their frequencies and calculate their probabilities . The amino-acid sequence of Citrobacter Freundii beta-lactamase was counted according to two-, three- and four-amino-acid sequences . The counted frequency and probability were compared with the predicted frequency and probability . The amino acid sequences, which appear in Citrobacter Freundii beta-lactamase and can be predicted from its amino acid composition according to a purely random mechanism, should not be deliberately evolved and conserved . By contrast, the amino acid sequences, which appear in Citrobacter Freundii beta-lactamase but cannot be predicted from its amino acid composition according to a purely random mechanism, should be deliberately evolved and conversed . Accordingly 99 (26.053%) and 33 (8.684%) of 380 two-amino-acid sequences can be predicted by the frequency and probability according to a purely random mechanism . Some kinds of amino acid sequences, which absent in Citrobacter Freundii beta-lactamase and can be predicted from its amino acid composition according to a purely random mechanism, should not be deliberately excluded from Citrobacter Freundii beta-lactamase . By contrast, some kinds of amino acid sequences, which absent in Citrobacter Freundii beta-lactamase and cannot be predicted from its amino acid composition according to a purely random mechanism, should be deliberately excluded from Citrobacter Freundii beta-lactamase . Accordingly 89 (48.370%) and 41 (22.283%) of 184 kinds of absent two-amino-acid sequences can be predicted by the frequency and probability according to a purely random mechanism, and 7236 (99.848%) of 7247 kinds of absent three-amino-acid sequences can be predicted by the frequency according to a purely random mechanism . The amino acids, whose probabilities in following certain preceding amino acids can be predicted from Citrobacter Freundii beta-lactamase amino acid composition according to a purely random mechanism, should not be deliberately evolved and conversed, accordingly 2 (0.526%) of 380 counted first order Markov transition probabilities for the second amino acid in two-amino-acid sequences match the predicted conditional probabilities. Microbiology, 2000 Aug, 146 ( Pt 8), 1855 - 67 Enzymically mediated bioprecipitation of uranium by a Citrobacter sp . : a concerted role for exocellular lipopolysaccharide and associated phosphatase in biomineral formation; Macaskie LE et al.; A Citrobacter sp . accumulated uranyl ion (UO2(2+)) via precipitation with phosphate ligand liberated by phosphatase activity . The onset and rate of uranyl phosphate deposition were promoted by NH4(+), forming NH(4)UO(2)PO(4), which has a lower solubility product than NaUO(2)PO(4) . This acceleration decoupled the rate-limiting chemical crystallization process from the biochemical phosphate ligand generation . This provided a novel approach to monitor the cell-surface-associated changes using atomic-force microscopy in conjunction with transmission electron microscopy and electron-probe X-ray microanalysis, to visualize deposition of uranyl phosphate at the cell surface . Analysis of extracted surface materials by (31)P NMR spectroscopy showed phosphorus resonances at chemical shifts of 0.3 and 2.0 p.p.m., consistent with monophosphate groups of the lipid A backbone of the lipopolysaccharide (LPS) . Addition of fUO2(2+) to the extract gave a yellow precipitate which contained uranyl phosphate, while addition of Cd(2+) gave a chemical shift of both resonances to a single new resonance at 3 p.p.m . Acid-phosphatase-mediated crystal growth exocellularly was suggested by the presence of acid phosphatase, localized by immunogold labelling, on the outer membrane and on material exuded from the cells . Metal deposition is proposed to occur via an initial nucleation with phosphate groups localized within the LPS, shown by other workers to be produced exocellularly in association with phosphatase . The crystals are further consolidated with additional, enzymically generated phosphate in close juxtaposition, giving high loads of LPS-bound uranyl phosphate without loss of activity and distinguishing this from simple biosorption, or periplasmic or cellular metal accumulation mechanisms . Accumulation of 'tethered' metal phosphate within the LPS is suggested to prevent fouling of the cell surface by the accumulated precipitate and localization of phosphatase exocellularly is consistent with its possible functions in homeostatis and metal resistance. Int J Antimicrob Agents, 2000 Aug, 15(3), 213 - 9 In vitro activity of 19 antimicrobial agents against 3513 nosocomial pathogens collected from 48 Canadian medical centres . The Canadian Antimicrobial Study Group; Blondeau JM et al.; Antimicrobial resistance is a global concern . Differentiation between susceptibility rates for nosocomial versus community pathogens is important epidemiologically because it impacts on the appropriate empirical selection of antimicrobial therapy for infected patients . We studied resistance rates for 3513 nosocomial pathogens from 48 Canadian medical centres tested against 19 antimicrobial agents . The following are percent susceptibility for ceftazidime, ceftriaxone, ciprofloxacin, imipenem, netilmicin, and ticarcillin/clavulanic acid, respectively: Enterobacteriaceae 95, 95, 97, 99 98, 89; Escherichia coli, all 99 except ticarcillin/clavulanic acid (91); Enterobacter spp . 78, 78, 96, 99, 99, 71; Citrobacter spp . 79, 80, 89, 100, 94, 73; Proteus spp . 99, 88, 99, 88, 99, 98; Pseudomonas aeruginosa 88, 20, 82, 88, 81, 36; Staphylococcus aureus, all > 95; Enterococcus spp . 4, 9, 62, 95, 43, 38 . Susceptibility rates for other species of microorganisms and agents tested varied considerably . Some institutions had higher than average resistance rates for some pathogens (i.e . P . aeruginosa) and some agents . Detection and continued surveillance of antimicrobial resistance amongst nosocomial pathogens is vital to patient care and health care resources . The control of antimicrobial resistance can help maintain antibiotic usage and costs associated with the use of ever more potent drugs and the treatment of increasingly resistant infections. Cesk Patol, 2000 May, 36(2), 65 - 70 {Diagnosis of malacoplakia in a transplanted kidney by needle biopsy}; Husek K et al.; Malakoplakia is an uncommon inflammatory condition rarely involving parenchyma of transplanted kidney . We report a 44-year-old female recipient of a cadaveric renal allograft treated with cyclosporin A and prednisone . After transplantation, E . coli and Citrobacter bacteruria occurred and three years later decreased graft function developed . Percutaneous needle biopsy was performed and diagnosis of malakoplakia was established . Histologically, interstitial sheets of plasmocytes and histiocytes with periodic acid-Shiff positive cytoplasm containing Michaelis-Gutmann bodies were present . Ultrastructurally, phagolysosomes containing membrane fragments and various developmental stages of inclusions to fully developed Michaelis-Gutmann bodies were found . The patient was treated with co-piperacillin and subsequently pefloxacin and renal functions improved after six months follow-up . Our case suggests that malakoplakia represents an abnormal defective histiocytic response to the infection in the setting of immunosuppressive therapy. Biochemistry, 2000 Jul 25, 39(29), 8546 - 55 The role of glutamic acid-69 in the activation of Citrobacter freundii tyrosine phenol-lyase by monovalent cations; Sundararaju B et al.; Tyrosine phenol-lyase (TPL) from Citrobacter freundii is activated about 30-fold by monovalent cations, the most effective being K(+), NH(4)(+), and Rb(+) . Previous X-ray crystal structure analysis has demonstrated that the monovalent cation binding site is located at the interface between subunits, with ligands contributed by the carbonyl oxygens of Gly52 and Asn262 from one chain and monodentate ligation by one of the epsilon-oxygens of Glu69 from another chain {Antson, A . A., Demidkina, T . V., Gollnick, P., Dauter, Z., Von Tersch, R . L., Long, J., Berezhnoy, S . N., Phillips, R . S., Harutyunyan, E . H., and Wilson, K . S . (1993) Biochemistry 32, 4195} . We have studied the effect of mutation of Glu69 to glutamine (E69Q) and aspartate (E69D) to determine the role of Glu69 in the activation of TPL . E69Q TPL is activated by K(+), NH(4)(+), and Rb(+), with K(D) values similar to wild-type TPL, indicating that the negative charge on Glu69 is not necessary for cation binding and activation . In contrast, E69D TPL exhibits very low basal activity and only weak activation by monovalent cations, even though monovalent cations are capable of binding, indicating that the geometry of the monovalent cation binding site is critical for activation . Rapid-scanning stopped-flow kinetic studies of wild-type TPL show that the activating effect of the cation is seen in an acceleration of rates of quinonoid intermediate formation (30-50-fold) and of phenol elimination . Similar rapid-scanning stopped-flow results were obtained with E69Q TPL; however, E69D TPL shows only a 4-fold increase in the rate of quinonoid intermediate formation with K(+) . Preincubation of TPL with monovalent cations is necessary to observe the rate acceleration in stopped flow kinetic experiments, suggesting that the activation of TPL by monovalent cations is a slow process . In agreement with this conclusion, a slow increase (k < 0.5 s(-)(1)) in fluorescence intensity (lambda(ex) = 420 nm, lambda(em) = 505 nm) is observed when wild-type and E69Q TPL are mixed with K(+), Rb(+), and NH(4)(+) but not Li(+) or Na(+) . E69D TPL shows no change in fluorescence under these conditions . High concentrations (>100 mM) of all monovalent cations result in inhibition of wild-type TPL . This inhibition is probably due to cation binding to the ES complex to form a complex that releases pyruvate slowly. Infect Immun, 2000 Aug, 68(8), 4637 - 46 Expression of intimin gamma from enterohemorrhagic Escherichia coli in Citrobacter rodentium; Hartland EL et al.; The carboxy-terminal 280 amino acids (Int280) of the bacterial adhesion molecule intimin include the receptor-binding domain . At least five different types of Int280, designated alpha, beta, gamma, delta, and epsilon, have been described based on sequence variation in this region . Importantly, the intimin types are associated with different evolutionary branches and contribute to distinct tissue tropism of intimin-positive bacterial pathogens . In this study we engineered a strain of Citrobacter rodentium, which normally displays intimin beta, to express intimin gamma from enterohemorrhagic Escherichia coli . We show that intimin gamma binds to the translocated intimin receptor (Tir) from C . rodentium and has the ability to produce attaching and effacing lesions on HEp-2 cells . However, C . rodentium expressing intimin gamma could not colonize orally infected mice or induce mouse colonic hyperplasia . These results suggest that intimin may contribute to host specificity, possibly through its interaction with a receptor on the host cell surface. Int J Food Microbiol, 2000 Jun 30, 58(1-2), 123 - 8 Assessment of the microbiological quality and wash treatments of lettuce served in University restaurants; Soriano JM et al.; One hundred and forty-four samples of lettuce from 16 University restaurants were analyzed . The mesophilic aerobic counts of all samples ranged from 3.01 to 7.81 log10 CFU g(-1) . Results of total coliforms ranged from < 0.47 to > 3.38 log10 most probable number (MPN) g(-1) . Of the lettuce samples, 25.7% harbored Escherichia coli, 22.9% Staphylococcus aureus and 84% group D streptococci . Similarly, 10.4% of the samples harbored Aeromonas hydrophila, 2.8% Pseudomonas aeruginosa, and coliforms such as 14.6% Citrobacter freundii, 8.3% Klebsiella pneumoniae, 4.2% Enterobacter cloacae and 1.4% Providencia spp . Salmonella, Shigella and E . coli O157:H7 were not detected . When sodium hypochlorite or potassium permanganate solutions were used in washing procedures, the aerobic microorganisms were reduced by more than two log units, and total coliforms by at least one log. J Perinatol, 2000 Jun, 20(4), 265 - 6 Citrobacter sepsis and severe newborn respiratory failure supported with extracorporeal membrane oxygenation; Rais-Bahrami K et al.; An infant with fulminant Citrobacter sepsis and respiratory failure is presented . The severity of respiratory failure and the need for systemic heparinization on extracorporeal membrane oxygenation delayed the opportunity of initial lumbar puncture to rule out meningitis . The infant was successfully treated with extracorporeal membrane oxygenation and long-term antibiotics . Repeated cranial computed tomography scans remained negative for intracerebral abscesses, and the infant is within normal limits for growth, neurologic status, and developmental status. Int J Food Microbiol, 2000 Jun 15, 57(3), 211 - 8 Modification of the bile salts-Irgasan-brilliant green agar for enumeration of Aeromonas species from food; Neyts K et al.; The present study evaluated the productivity of BIBG medium for the isolation of Aeromonas spp . from food and describes a modification of the BIBG medium (mBIBG) (increased pH (8.7), replacement of xylose by soluble starch as a carbon source, decreased concentration of bile salts) to increase its selectivity and electivity . Using the mBIBG medium, growth of the majority of the Enterobacteriaceae (9/10) was suppressed except for Citrobacter freundii . The mBIBG medium supported growth of Pseudomonas species but a clear distinction between Aeromonas and Pseudomonas colonies could be made . Interpretation of the mBIBG medium should be performed after 24 h of incubation . It was noted that three of the 27 Aeromonas strains tested did not develop on the mBIBG medium . The ability or inability to grow on a selective medium is strain-dependent . Enumeration of Aeromonas species (A . hydrophila LMG 3771, A . caviae LMG 3775, A . veronii biovar veronii LMG 9075, A . veronii biovar sobria LMG 13071) from artificially contaminated foods (shrimp, minced meat (beef/pork), precut leek, and shredded carrots) confirmed that the mBIBG medium is suitable for quantitative recovery of aeromonads (ca . 10(2)-10(7) cfu/g) in the presence of a high background flora (10(5)-10(6) cfu/g) . Screening of naturally contaminated foods (vegetables, seafood, meat) for the presence of Aeromonas resulted in three out of 14 food samples showing presumptive Aeromonas colonies on mBIBG. Chemotherapy, 2000 Jul-Aug, 46(4), 253 - 66 In vitro activity of rifaximin, metronidazole and vancomycin against Clostridium difficile and the rate of selection of spontaneously resistant mutants against representative anaerobic and aerobic bacteria, including ammonia-producing species; Marchese A et al.; BACKGROUND: Rifaximin is a rifamycin derivative characterized by a wide antibacterial activity . This drug is neither absorbed by the gastrointestinal tract nor inactivated by gastric juices, and exerts its action entirely within the intestinal lumen . METHODS: In this study, the activity of this antibiotic was compared with that of metronidazole and vancomycin against 93 Clostridium difficile isolates . The rate of emergence of bacteria spontaneously resistant to the new compound was also evaluated in relation to representative gram-positive and gram-negative strains . In terms of MIC(50) values, rifaximin showed an intrinsic activity superior to that of the other agents . The emergence of spontaneously resistant strains was assessed with 46 aerobic (staphylococci, enterococci, Proteus spp., Citrobacter freundii, Providencia rettgeri, enteropathogenic, enteroinvasive, enterotoxigenic and entero- hemorrhagic Escherichia coli, and Salmonella enteritidis) and anaerobic (Clostridium spp., Bacteroides spp., Fusobacterium nucleatum and Peptococcus spp.) pathogens, most of them also ammonium producers . Two different methods, broth and agar dilution, were employed . RESULTS: When liquid medium was employed, bacteria capable of sustained growth in 100 microg/ml of rifaximin were obtained after 2-5 transfers with gram-positive aerobic cocci, 2-3 transfers with gram-negative aerobic strains and 2-5 transfers with anaerobic species . At the highest dose used with the agar dilution method (8 x MIC), the frequency of emergence of spontaneously resistant mutants ranged from <1 x 10(-9) to 1.6 x 10(-8) with gram-positive aerobic and anaerobic cocci, while with aerobic and anaerobic gram-negative bacteria, this value ranged from <1 x 10(-9) to 1.7 x 10(-7) . C . difficile showed a particularly low incidence of spontaneously resistant mutants (<1 x 10(-9)) . The low incidence of resistant subpopulations selected by levels of 8 x MIC of rifaximin suggests that the high levels of the drug which were reached in the gastrointestinal lumen may further prevent the selection of mutants . CONCLUSION: The low toxicity, broad antibacterial activity and very poor absorption from the gastrointestinal tract of rifaximin suggest a potential therapeutic use for this drug in gastrointestinal diseases, as well as in the management of patients with cirrhosis and chronic portal-systemic encephalopathy . Antimicrob Agents Chemother, 2000 Jul, 44(7), 1936 - 42 A novel CTX-M beta-lactamase (CTX-M-8) in cefotaxime-resistant Enterobacteriaceae isolated in Brazil; Bonnet R et al.; To estimate the diversity of extended-spectrum beta-lactamases in Brazil, 18 strains from different species of the family Enterobacteriaceae exhibiting a positive double-disk synergy test were collected by a clinical laboratory from several hospitals in Rio de Janeiro, Brazil, in 1996 and 1997 . Four strains (Proteus mirabilis, Enterobacter cloacae, Enterobacter aerogenes, and Citrobacter amalonaticus) hybridized with a 550-bp CTX-M probe . The P . mirabilis strain produced a CTX-M-2 enzyme . The E . cloacae, E . aerogenes, and C . amalonaticus isolates harbored a bla gene which was identified by cloning and sequencing as a bla(CTX-M) gene . E . coli HB101 transconjugants and the E . coli DH5alpha transformant harboring a recombinant plasmid produced a CTX-M beta-lactamase with an isoelectric point of 7.6 conferring a resistance phenotype characterized by a higher level of resistance to cefotaxime than to ceftazidime, as observed with the other CTX-M enzymes . The deduced protein sequence showed a novel Ambler class A CTX-M enzyme, named CTX-M-8, which had 83 to 88% identity with the previously described CTX-M enzymes . The phylogenic study of the CTX-M family including CTX-M-8 revealed four CTX-M types, CTX-M-8 being the first member of a new phylum of CTX-M enzymes . The evolutionary distances between the four types of CTX-M were large, suggesting that the four clusters branched off early from a distant unknown enzyme and that intermediate enzymes probably existed. Int J Antimicrob Agents, 2000 Jul, 15(2), 111 - 8 In vitro efficacy of six cephalosporins tested against Enterobacteriaceae isolated at 38 North American medical centres participating in the SENTRY Antimicrobial Surveillance Program, 1997-1998; Jones RN et al.; The SENTRY Antimicrobial Surveillance Program is an ongoing international collaboration that monitors the predominant bacterial and fungal pathogens and antimicrobial susceptibility patterns associated with community-acquired and nosocomial infections . SENTRY data on the current cephalosporin susceptibility patterns (1997-98) of North American isolates of clinically important Enterobacteriaceae were analyzed . Susceptibility to a selection of cephalosporins was assessed at a central laboratory using reference broth microdilution methods and interpretive criteria specified by the National Committee for Clinical Laboratory Standards . The third- and fourth-generation cephalosporins tested demonstrated excellent activity against Escherichia coli and Klebsiella pneumoniae, whereas some of the older agents maintained good efficacy . Extended spectrum beta-lactamases were detected in all regions of the United States and Canada (1.8-10.7%) . Cefepime was the most active agent tested against pathogens with the potential for enzyme-mediated resistance due to Amp C . The third-generation agents maintained acceptable efficacy against Serratia marcescens, but were less effective against Citrobacter and Enterobacter species . The older cephalosporins were generally inadequate against these pathogens, in contrast to cefepime, which was the widest spectrum cephalosporin overall . Some significant regional variations in spectrum were detected. Trop Gastroenterol, 2000 Jan-Mar, 21(1), 35 - 6 Enteropathogenic Escherichia coli isolates in paediatric diarrhoea; Vaishnavi C et al.; Enteropathogenic Escherichia coli (EPEC) are known to cause infantile enteritis . We studied the prevalence of EPEC in paediatric patients with acute and persistent diarrhoea . A total of 56 stool samples from paediatric patients were studied . There were 28 significant bacterial isolates . Of these 21 were untypable E . coli, 5 were typable E . coli, four of which belonged to members considered to be enteropathogenic . Non E . coli isolates grown in pure culture were one each of Pseudomonas aeruginosa and Citrobacter freundi . The study reveals the definitive role of EPEC in childhood diarrhoea at all age groups and emphasizes the need for characterisation of all significant E . coli isolates in this age group. J Food Prot, 2000 May, 63(5), 655 - 8 Prevalence of Salmonella spp . in poultry broilers and shell eggs in Korea; Chang YH; This study was conducted to determine the presence of Salmonella spp . in raw broilers and shell eggs in Korea . In total, 135 dozen shell eggs and 27 raw broilers were tested . None of the egg yolks were found to contain Salmonella organisms but Escherichia coli, Escherichia hermanii, and Citrobacter freundii were isolated from egg shells . Salmonella spp . were detected in 25.9% of raw broilers, and Salmonella serotypes isolated from raw broilers were Salmonella Enteritidis, Salmonella Virchow, and Salmonella Virginia . D-values and antibiotic resistance of Salmonella isolates were also investigated . D-values of Salmonella enteritidis, Salmonella Virginia, and Salmonella Virchow in tryptic soy broth at 55 degrees C were 2.36, 2.13, and 0.70 min and 0.53, 0.37, and 0.20 min at 60 degrees C, respectively . All Salmonella isolates showed multiple antibiotic resistance patterns and were resistant to penicillin and vancomycin . One strain of Salmonella Enteritidis showed resistance to 12 antibiotics used in this study. Anal Biochem, 2000 Apr 10, 280(1), 166 - 72 Molecular beacons: a real-time polymerase chain reaction assay for detecting Salmonella; Chen W et al.; Molecular beacons are oligonucleotide probes that become fluorescent upon hybridization . We developed a real-time PCR assay to detect the presence of Salmonella species using these fluorogenic reporter molecules . A 122-base-pair section of the himA was used as the amplification target . Molecular beacons were designed to recognize a 16-base-pair region on the amplicon . As few as 2 colony-forming unit (CFU) per PCR reaction could be detected . We also demonstrated the ability of the molecular beacons to discriminate between amplicons obtained from similar species such as Escherichia coli and Citrobacter freundii in real-time PCR assays . These assays could be carried out entirely in sealed PCR tubes, enabling fast and direct detection of Salmonella in a semiautomated format. Subcell Biochem, 2000, 33, 47 - 59 E . coli invasion of brain microvascular endothelial cells as a pathogenetic basis of meningitis; Kim KS; A major limitation to advances in prevention and therapy of bacterial meningitis is our incomplete understanding of the pathogenesis of this disease . Successful isolation and cultivation of BMEC, which constitute the blood brain barrier, and the development of experimental hematogenous meningitis animal model, which mimics closely the pathogenesis of human meningitis, enabled us to dissect the pathogenetic mechanisms of bacterial meningitis . We have shown for the first time using E . coli as a paradigm the mechanisms of bacterial crossing of the blood-brain barrier into the central nervous system . We have shown that invasion of BMEC is a requirement for E . coli K1 crossing of the blood-brain barrier in vivo (Prasadarao et al., 1996b; Huang et al., 1995) . We have identified several novel E . coli proteins (i.e., Ibe10, Ibe7, and Ibe23) contributing to invasion of BMEC . We have also established a novel phenotype, i.e., invasion of BMEC, of a well known major E . coli protein, OmpA . In addition, we have shown that some of these E . coli proteins (i.e., OmpA, Ibe10) interact with novel endothelial receptors present on BMEC, not on systemic vascular endothelial cells . Further understanding and characterization of these E . coli-BMEC interactions should allow us to develop novel strategies to prevent this serious infection . In addition, the in vitro and in vivo models of the blood-brain barrier and the information derived from our study should be beneficial to investigating the pathogenesis of meningitis due to other organisms such as group B streptococci, Listeria monocytogenes, Streptococcus pneumoniae and Citrobacter. Med Dosw Mikrobiol, 1999, 51(3-4), 311 - 21 {Differentiation of Citrobacter strains using chromosomal DNA restriction patterns}; Cieslik A et al.; The aim of this study was checking of the usefulness of chromosomal DNA restriction patterns in differentiation of Citrobacter strains . Molecular characterization of total 56 isolates of Citrobacter from Poland and Czech Republic, was performed by pulsed-field gel electrophoresis after digestion of chromosomal DNA with restriction endonuclease Xba I (5'-TCTAGA-3') . Chromosomal DNA of all tested Citrobacter strains gave after electrophoresis 12 to 21 bands and patterns consisting of 12 to 21 fragments ranging in size from 790 kb to 48.5 kb and smaller, which where not distinguishable . Pulsed-field gel electrophoresis patterns were useful for comparing Citrobacter strains . Identical restriction patterns generated by PFGE were observed in the case of selected strains e.g . strains C . sedlakii studied in this study, coming from an outbreak, having the some phenotype . In addition, PFGE patterns can be used to evaluate the clonal relatedness among bacterial isolates . PFGE can be helpful for assessing genetic relatedness among strains epidemiologicaly unrelated e.g . C . werkmanii strains tested in this study . The sum of DNA fragments after Xba I digestion indicates the genome size of Citrobacter strains . This suggests that PFGE should be useful for epidemiological investigations of Citrobacter strains. Med Dosw Mikrobiol, 1999, 51(3-4), 301 - 9 {Differentiation of Citrobacter strains using electrophoretic protein patterns}; Cieslik A; The aim of this study was checking of the usefulness of electrophoretic protein patterns in differentiation of Citrobacter strains . For analysis of whole-cell proteins 181 Citrobacter strains were prepared . Electrophoresis was performed in Mini Protean Duall Slab Cell (Bio-Rad) apparatus . Electrophoresis was carried out in 10% polyacrylamide gel according to the SDS-PAGE method of Laemmli . Whole-cell proteins of all tested Citrobacter strains gave after electrophoresis 12 to 20 bands . Patterns consisting of 12 to 20 fragments ranging in size from 70,000 to 14,000 and smaller, were not distinguishable . There were no significant differences between electrophorograms of Citrobacter strains belonging to the different species, useful for species differentiation . Identical protein band patterns were observed in the case of selected strains e.g . strains C . sedlakii studied in this study, coming from an outbreak, having the some phenotype. Med Dosw Mikrobiol, 1999, 51(3-4), 289 - 99 {Taxonomy of Citrobacter rods found in human specimens}; Cieslik A; The aim of this study was the identification of 181 Citrobacter strains on the basis of the recently proposed taxonomic changes of Brenner . All strains were isolated from diarrhoeic patients; 124 strains were originally sent for identification to Laboratory of Enterobacteriaceae DB NIH, 57 strains was isolated in Czech Republic . Citrobacter isolates were initially identified as C . koseri (3 strains), C . amalonaticus (1 strain) or as members of the C . freundii complex (177 strains) . Additionally some biochemical tests were performed . The ability to grow in medium containing KCN, lysine decarboxylase production, lactose fermentation and PYR test were examined . Strains belonging to the C . freundii complex were identified to the species level by biochemical methods on the basis of the results of Brenner, who found some tests to be useful in separating Citrobacter species . These test included citrate and acetate utilization, arginine dihydrolase and ornithine decarboxylase activities, motility, urease production, esculin hydrolysis, and acid production from sucrose, dulcitol, melibiose, raffinose and salicin . On the basis of the criteria described above, 96.6% of the strains tested could be assigned to one of the recently named species of C . freundii complex . Using biochemical tests suggested by Brenner we were able to identify Citrobacter strains members of newly recognised species . A five-test system is proposed to identify the most frequently encountered species currently residing in the C . freundii complex. FEMS Immunol Med Microbiol, 2000 Jun, 28(2), 163 - 71 Structure and serologic properties of O-specific polysaccharide from Citrobacter freundii possessing cross-reactivity with Escherichia coli O157:H7; Nishiuchi Y et al.; Citrobacter freundii OCU158 is a serologically cross-reactive strain with Escherichia coli O157:H7 . To explore the close relationship between two strains, we have analyzed the chemical structures of O-specific polysaccharides and antigenic properties of lipopolysaccharides (LPSs) of both strains . The structure of O-specific polysaccharides from both strains was found to be identical by chemical and nuclear magnetic resonance analyses, in which D-PerNAc was 4-acetamido-4,6-dideoxy-D-mannose: {-->4)-beta-D-Glc-(1-->3)-alpha-D-PerNAc-(1-->4)-alpha-D-GalNAc-(1 --> 3)-alpha-L-Fuc-(1-->}(n) . The enzyme immunoassay using LPS derived either from E . coli O157 or from C . freundii could equally detect high levels of serum antibodies against LPS in patients with enterohemorrhagic E . coli (EHEC) O157 infection . Absorption of antibodies in EHEC patient serum by LPS from E . coli O157 or C . freundii, however, showed a difference in the epitopes . This difference was attributable to the epitope specificity of the core region and/or lipid A structure in LPS. East Mediterr Health J, 1999 Jan, 5(1), 130 - 5 Isolation of Yersinia enterocolitica from cases of acute appendicitis and ice-cream; el-Sherbini M et al.; Seventy (70) appendiceal specimens and 80 ice-cream samples were analysed to detect Yersinia enterocolitica using three different media . Both Y . enterocolitica and Citrobacter freundii were recovered in appendiceal specimens (17.1% and 8.6%) and ice-cream (26.25% and 18.75%) respectively . Thioglycollate medium was more selective and productive in isolating Yersinia . Y . enterocolitica was the major causative agent of acute appendicitis (11/25, 44%) . It was sensitive to chloramphenicol, gentamicin, tetracycline and trimethoprim- sulfamethoxazole. Kansenshogaku Zasshi, 2000 Mar, 74(3), 250 - 8 {Detection of extended spectrum beta-lactamases producing Enterobacteriaceae in feces}; Komatsu M et al.; A study was made of 366 feces for detection of extended spectrum beta-lactamases producing Enterobacteriaceae from feces . The selective agar was used for modified drigalski agar (Eiken Chemical Co., LTD) with 2 micrograms/ml cefotaxime (ESBL screen agar) . 92 strains of Enterobacteriaceae, 41 Escherichia coli, 15 Citrobacter freundii, 13 Enterobacter cloacae, 11 Klebsiella pneumoniae, and other 12, were isolated from ESBL screen agar . And, R-plasmid that were selected by 2 micrograms/ml cefotaxime were transferred by conjugation from two of the 92 strains . These strain were E . coli TH9809927 and Proteus mirabilis TH9808262 that were amplified by "Toho-1 type" primer . The clude enzyme from two strains (donor) and transconjugants were especially hydrolysed cepharoridine and cefotaxime . Accordingly, two strains (0.5%) were detected as ESBL producers . We think that the result of our survey suggests the increase of ESBLs producing bacterial infection in Japan, and believe that there is a trend of infection of its by surveilance of the feces. J Clin Gastroenterol, 2000 Apr, 30(3), 317 - 20 Ascending cholangitis as a cause of pyogenic liver abscesses complicated by a gastric submucosal abscess and fistula; Yamada T et al.; Ruptures of nonamebic (pyogenic) liver abscesses into the thorax and peritoneum are very uncommon; but, hepatoduodenal and hepatocolonic fistulas are ever more rare . We report a case where ascending cholangitis was associated with pyogenic liver abscess formation and a gastric fistula . Drainage into the stomach was demonstrated by gastroduodenal endoscopy for gastric bleeding . After fistula formation, we could successfully treat the inflammation caused by infection of Citrobacter freundii and Candida albicans with intravenous infusion of both antibiotic and antifungal agents. Protein Eng, 2000 Mar, 13(3), 207 - 15 Citrobacter freundii tyrosine phenol-lyase: the role of asparagine 185 in modulating enzyme function through stabilization of a quinonoid intermediate; Barbolina MV et al.; Asn185 is an invariant residue in all known sequences of TPL and of closely related tryptophanase and it may be aligned with the Asn194 in aspartate aminotransferase . According to X-ray data, in the holoenzyme and in the Michaelis complex Asn185 does not interact with the cofactor pyridoxal 5'-phosphate, but in the external aldimine a conformational change occurs which is accompanied by formation of a hydrogen bond between Asn185 and the oxygen atom in position 3 of the cofactor . The substitution of Asn185 in TPL by alanine results in a mutant N185A TPL of moderate residual activity (2%) with respect to adequate substrates, L-tyrosine and 3-fluoro-L-tyrosine . The affinities of the mutant enzyme for various amino acid substrates and inhibitors, studied by both steady-state and rapid kinetic techniques, were lower than for the wild-type TPL . This effect mainly results from destabilization of the quinonoid intermediate, and it is therefore concluded that the hydrogen bond between Asn185 and the oxygen at the C-3 position of the cofactor is maintained in the quinonoid intermediate . The relative destabilization of the quinonoid intermediate and external aldimine leads to the formation of large amounts of gem-diamine in reactions of N185A TPL with 3-fluoro-L-tyrosine and L-phenylalanine . For the reaction with 3-fluoro-L-tyrosine it was first possible to determine kinetic parameters of gem-diamine formation by the stopped-flow method . For the reactions of N185A TPL with substrates bearing good leaving groups the observed values of k(cat) could be accounted for by taking into consideration two effects: the decrease in the quinonoid content under steady-state conditions and the increase in the quinonoid reactivity in a beta-elimination reaction . Both effects are due to destabilization of the quinonoid and they counterbalance each other . Multiple kinetic isotope effect studies on the reactions of N185A TPL with suitable substrates, L-tyrosine and 3-fluoro-L-tyrosine, show that the principal mechanism of catalysis, suggested previously for the wild-type enzyme, does not change . In the framework of this mechanism the observed considerable decrease in k(cat) values for reactions of N185A TPL with L-tyrosine and 3-fluoro-L-tyrosine may be ascribed to participation of Asn185 in additional stabilization of the keto quinonoid intermediate. J Antimicrob Chemother, 2000 Apr, 45(4), 521 - 4 In vitro selected fluoroquinolone-resistant mutants of Citrobacter freundii: analysis of the quinolone resistance acquisition; Tavio M et al.; Ten quinolone-resistant mutants of Citrobacter freundii, which were selected in vitro with fluoroquinolones from two clinical isolates, were studied . The parent isolates were susceptible to quinolones in spite of showing a single substitution in the GyrB (His-417 --> Leu) . No change was observed in the outer membrane proteins or in the lipopolysaccharide in any of the ten mutants studied with respect to their parent isolates . The development of quinolone resistance in selected mutants was associated with the appearance of a substitution in the GyrA (Thr-83 --> Ile) in nine of the ten mutants plus enhanced active efflux in all of them. Avian Dis, 2000 Jan-Mar, 44(1), 85 - 98 Minimum inhibitory concentration determinations for various antimicrobial agents against 1570 bacterial isolates from turkey poults; Salmon SA et al.; Minimum inhibitory concentrations (MICs) were determined for 1570 bacteria from eight geographic locations (1204 Escherichia coli, 231 other enteric gram-negative bacilli {including Citrobacter spp., Enterobacter spp., Klebsiella spp., Proteus spp., and Salmonella spp.}, 31 Pseudomonas spp., 18 coagulase-positive staphylococci, 26 coagulase-negative staphylococci, and 55 streptococci and enterococci) by the National Committee for Clinical Laboratory Standards broth microdilution procedure . Antimicrobial agents tested included ampicillin, ceftiofur, enrofloxacin, erythromycin, florfenicol, gentamicin, neomycin, spectinomycin, sulfamethazine, tetracycline, and trimethoprim/sulfadiazine . Against the E . coli strains tested, ceftiofur, enrofloxacin, gentamicin, and trimethoprim/sulfadiazine were the most active compounds with MIC at which 50% of the strains are at or below (MIC50) = 0.5, < or = 0.03, 0.5, and 0.13 microg/ml, respectively, and MIC at which 90% of the strains are at or below (MIC90) = 1.0, 0.13, 32.0, and 2.0 microg/ml, respectively . Ampicillin, florfenicol, neomycin, and spectinomycin were the next most active compounds against the E . coli strains, with MIC50 = 4.0, 4.0, 16.0, and 16.0 microg/ml, respectively . MIC90 values for these compounds against E . coli strains were > 32.0, 8.0, 512.0, and > 128.0 microg/ml, respectively . The remaining compounds exhibited limited, strain-dependent activity against the E . coli strains tested . As with the E . coli, enrofloxacin, ceftiofur, and trimethoprim/sulfadiazine were also the most active compounds against the 231 other enteric organisms tested, with MIC50 < or = 1.0 microg/ml for all of these genera . The remaining compounds exhibited limited activity against these genera . Against the gram-positive cocci tested, ampicillin, enrofloxacin, ceftiofur, and trimethoprim/sulfadiazine were most active, whereas the remaining compounds exhibited strain-dependent activity . When MIC data for E . coli were summarized separately, differences were observed between the geographic locations for the various antimicrobial agents . In conclusion, ceftiofur, enrofloxacin, and trimethoprim/sulfadiazine were the most active of the compounds tested against all of the bacterial strains. APMIS, 2000 Feb, 108(2), 145 - 52 The prevalence of gentamicin resistance among clinical isolates of enterobacteria in a Danish region; Schonheyder HC et al.; The susceptibility of enterobacteria to gentamicin was studied in the County of North Jutland during 1993-1998 . A total of 378 patients had a first-time gentamicin-resistant isolate . The annual number rose from 34 patients in 1993 to 89 in 1998 . The prevalence of resistance per 1000 patients with isolates examined was 13.5 for Escherichia coli, 15.8 for Klebsiella pneumoniae, 26.1 for Klebsiella oxytoca, and 150.4 for Citrobacter freundii . E . coli accounted for 67% of gentamicin-resistant isolates . K . oxytoca was probably associated with a nosocomial epidemic, whereas a source for C . freundii remained unresolved . An analysis confined to E . coli identified specimens other than urine as risk factors for gentamicin resistance . Likewise, resistance to sulfonamides and to fluoroquinolones were strong risk factors for gentamicin resistance among urinary isolates of E . coli . Thus, it is likely that aminoglycoside resistance may be promoted by other antibiotic groups due to co-resistance . The therapeutic and prophylactic uses of aminoglycosides have as yet not been undermined, but continuous population-based surveillance and vigilance are recommended. Eur J Biochem, 2000 Mar, 267(6), 1830 - 6 Pyridoxal 5'-phoshate schiff base in Citrobacter freundii tyrosinephenol-lyase . Ionic and tautomeric equilibria; Bazhulina NP et al.; Spectral properties of the internal Schiff base in tyrosine phenol-lyase have been investigated in the presence of an activating cation K+ and a cation-inhibitor Na+ . The holoenzyme absorption spectra in the pH range 6.5-8.7 were recorded in the presence of K+ . No apparent pKa value of the coenzyme chromophore was found in this pH range, indicating that the internal Schiff base does not change its ionic form on going from pH 6.5 to 8.7 . To determine the ionic state and tautomeric composition of the Schiff base in tyrosine phenol-lyase, the absorption and circular dichroism spectra were analyzed using lognormal distribution curves . The predominant form of the internal Schiff base is that with protonated pyridinium and aldimine nitrogen atoms and deprotonated 3'-hydroxy group, i.e . the ketoenamine . This form is in prototropic equilibrium with its enolimine tautomer . The internal aldimine ionic form is changed upon replacement of K+ with Na+ . This replacement leads to a significant decrease in the pKa value of pyridinium nitrogen of the pyridoxal-P. Jpn J Antibiot, 2000 Jan, 53(1), 46 - 59 {The resistance of recent clinical isolates against isepamycin, other aminoglycosides and injectable beta-lactams}; O'Hara K et al.; Clinical isolates collected from clinical facilities across Japan in 1998 were tested against five aminoglycosides and three beta-lactams . The resistance of 50 strains each of methicillin sensitive Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, Citrobacter freundii, Klebsiella pneumoniae, Enterobacter sp., Serratia sp., Pseudomonas aeruginosa and Proteus sp . (P . mirabilis 25 strains and P . vulgaris 25 strains) to the aminoglycosides isepamicin (ISP), amikacin (AMK), gentamicin, tobramycin and dibekacin, and to the beta-lactams imipenem, ceftazidime and piperacillin (all three known to be effective against P . aeruginosa) were investigated using a micro liquid dilution method with the following results: 1 . ISP was effective against all strains except for 14% of MRSA, 2% of Proteus sp., and 4% of P . aeruginosa . 2 . Six strains of MRSA were resistant to all eight drugs; however, in these cases ISP exhibited a relatively low minimum inhibitory concentration (MIC) compared to the other compounds . 3 . Four strains of MRSA were resistant to all drugs except ISP . MRSA was the only isolate to demonstrate a resistance to seven or more drugs . 4 . Twenty-one strains of MRSA and 1 strain of P . aeruginosa were resistant to six drugs; however, all of these were susceptible to both ISP and AMK . 5 . Against all strains tested, ISP generally exhibited a lower MIC compared to AMK . These results suggest that, even ten years after its entering the market, ISP is still an aminoglycoside having a high anti-bacterial activity against a wide range of clinical isolates. Cytobios, 2000, 101(396), 15 - 21 Occurrence and antibiotic sensitivity of Enterobacteriaceae isolated from a group of Jordanian patients with community acquired urinary tract infections; Abu Shaqra Q; The type and antibiotic sensitivity of urinary tract pathogens may differ in various communities . Of 207 isolates recovered from midstream urine specimens collected from a group of patients with community acquired urinary tract infections (UTI), 86% were species of Enterobacteriaceae . The most frequently recovered pathogens were Escherichia coli (82%), Klebsiella spp . (7.3%), Proteus spp . (6.2%), Enterobacter spp . (3.4%) and Citrobacter spp . (1.1%) . High rates of resistance were found against ampicillin (95%), tetracycline (86%), carbenicillin (84%), trimethoprim/sulphamethoxazole (48%), and amoxycillin/clavulanic acid (45%) . For the antibiotics tobramycin, aztreonam, ceftriaxone and gentamicin 7% of the isolates were resistant, while resistance varied from 9-18% for amikacin, ciprofloxacin, norfloxacin, nalidixic acid and cefuroxime . The incidence of UTI caused by Enterobacteriaceae was three times higher in females than in males, particularly in young and middle age groups (< or = 19 and 20-39 years). J Food Prot, 2000 Feb, 63(2), 264 - 7 Specificity of a conductance assay for enumeration of Escherichia coli from broiler carcass rinse samples containing genetically similar species; Edmiston AL et al.; Experiments were conducted to evaluate the specificity of a rapid method for enumeration of Escherichia coli from fresh broiler chicken carcasses . In three separate trials, E . coli, Citrobacter freundii, Salmonella Enteritidis, and Shigella sonnei were serially diluted and then inoculated into identical broiler chicken carcass rinses . Inoculated rinses were mixed with double-strength Coliform Medium supplemented with 2% dextrose . This mixture was placed in a Bactometer module in duplicate, and conductance was measured at 44 degrees C . Results indicated that C . freundii did not grow to an appreciable degree in the selective medium at 44 degrees C . Salmonella Enteritidis grew similarly to E . coli; however, an initial level of 10(6) Salmonella in the food product would be required for Salmonella to interfere with enumeration of E . coli using this method . S . sonnei grew at a more rapid rate than E . coli; however, there was an interaction between the regression lines formed when serial dilutions (log10 CFU/ml) were compared to E . coli detection times for these two species of bacteria . Therefore, high levels of S . sonnei in a food sample may interfere with the enumeration of E . coli . In general, Salmonella and Shigella are not found at high enough levels on poultry products to interfere with enumeration of E . coli using this method and, if found at high levels, would be detected and rejected using this procedure . Hence, the presence