Publications

trends in antimicrobial susceptibilities among enterobacteriaceae isolated from hospitalized patients in the united states from 1998 to 2001.	longitudinal surveillance of enterobacteriaceae for antimicrobial susceptibility is important because species of this family are among the most significant and prevalent human pathogens. to estimate rates of in vitro antimicrobial susceptibility among hospitalized patients in the united states, data from the surveillance network were studied for 14 agents tested against 10 species of enterobacteriaceae (n = 384,279) isolated from intensive-care-unit (icu) patients and non-icu inpatients from 199 ...	2003	12709339
burkholderia is highly resistant to human beta-defensin 3.	the bactericidal activity of the novel beta-defensin hbd-3 against 28 species and 55 strains of gram-positive cocci and gram-negative fermentative and nonfermentative rods was tested. all strains proved to be highly or intermediately susceptible to hbd-3 (minimal bactericidal concentration [mbc], </=50 micro g/ml), except for burkholderia cepacia, for all 23 tested strains of which mbcs were >100 micro g/ml.	2003	12709350
evaluation of the vitek 2 id-gnb assay for identification of members of the family enterobacteriaceae and other nonenteric gram-negative bacilli and comparison with the vitek gni+ card.	we evaluated the vitek 2 id-gnb identification card (biomérieux, inc., durham, n.c.) for its ability to identify members of the family enterobacteriaceae and other gram-negative bacilli that are isolated in clinical microbiology laboratories. using 482 enteric stock cultures and 103 strains of oxidase-positive, gram-negative glucose-fermenting and nonfermenting bacilli that were maintained at -70 degrees c and passaged three times before use, we inoculated cards according to the manufacturer's d ...	2003	12734254
citrobacter freundii septicemia in two dogs.	a 4-month-old maltese puppy and a 7.5-year-old collie were diagnosed with septicemia associated with citrobacter freundii. the puppy died soon, after developing weakness and mucohemorragic diarrhea. the collie had immune-mediated hemolytic anemia and thrombocytopenia and was treated with immunosuppressive drugs before being euthanized. gross examination of the puppy revealed mucohemorrhagic intestinal contents. focal necrotic hepatitis, fibrinous peritonitis, interstitial pneumonia, and hemorrha ...	2003	12735357
recombinant truncated flagellin of burkholderia pseudomallei as a molecular probe for diagnosis of melioidosis.	current serological tests for melioidosis, using impure or uncharacterized cell antigens from burkholderia pseudomallei, have problems in detection sensitivity and specificity. therefore, we designed and expressed the recombinant flagellin (truncated at both the n- and c-terminal ends), and used the antigen to develop an indirect enzyme-linked immunosorbent assay (elisa) to diagnose melioidosis. comparison of the immunoreactivities of the full-length and truncated flagellins reveals that the tru ...	2003	12738642
rna-structural mimicry in escherichia coli ribosomal protein l4-dependent regulation of the s10 operon.	ribosomal protein l4 regulates the 11-gene s10 operon in escherichia coli by acting, in concert with transcription factor nusa, to cause premature transcription termination at a rho-independent termination site in the leader sequence. this process presumably involves l4 interaction with the leader mrna. here, we report direct, specific, and independent binding of ribosomal protein l4 to the s10 mrna leader in vitro. most of the binding energy is contributed by a small hairpin structure within th ...	2003	12738792
experimental prediction of the evolution of cefepime resistance from the cmy-2 ampc beta-lactamase.	understanding of the evolutionary histories of many genes has not yet allowed us to predict the evolutionary potential of those genes. intuition suggests that current biochemical activity of gene products should be a good predictor of the potential to evolve related activities; however, we have little evidence to support that intuition. here we use our in vitro evolution method to evaluate biochemical activity as a predictor of future evolutionary potential. neither the class c citrobacter freun ...	2003	12750318
immunity profiles of wild-type and recombinant shiga-like toxin-encoding bacteriophages and characterization of novel double lysogens.	the pathogenicity of shiga-like toxin (stx)-producing escherichia coli (stec), notably serotype o157, the causative agent of hemorrhagic colitis, hemolytic-uremic syndrome, and thrombotic thrombocytopenic purpura, is based partly on the presence of genes (stx(1) and/or stx(2)) that are known to be carried on temperate lambdoid bacteriophages. stx phages were isolated from different stec strains and found to have genome sizes in the range of 48 to 62 kb and to carry either stx(1) or stx(2) genes. ...	2003	12761125
host susceptibility to the attaching and effacing bacterial pathogen citrobacter rodentium.	many studies have shown that genetic susceptibility plays a key role in determining whether bacterial pathogens successfully infect and cause disease in potential hosts. surprisingly, whether host genetics influence the pathogenesis of attaching and effacing (a/e) bacteria such as enteropathogenic and enterohemorrhagic escherichia coli has not been examined. to address this issue, we infected various mouse strains with citrobacter rodentium, a member of the a/e pathogen family. of the strains te ...	2003	12761129
spectrum and antibiotic sensitivity of bacteria contaminating the upper gut in patients with malabsorption syndrome from the tropics.	various causes of malabsorption syndrome (mas) are associated with intestinal stasis that may cause small intestinal bacterial overgrowth (sibo). frequency, nature and antibiotic sensitivity of sibo in patients with mas are not well understood.	2003	12769832
altered substrate selection of the melibiose transporter (mely) of enterobacter cloacae involving point mutations in leu-88, leu-91, and ala-182 that confer enhanced maltose transport.	we isolated mutants of escherichia coli hs4006 containing the melibiose-h(+) symporter (mely) from enterobacter cloacae that had enhanced fermentation on 1% maltose macconkey plates. dna sequencing revealed three site classes of mutations: l-88-p, l-91-p, and a-182-p. the mutants l-88-p and l-91-p had 3.6- and 5.1-fold greater maltose uptake than the wild type and enhanced apparent affinities for maltose. energy-coupled transport was defective for melibiose accumulation, but detectable maltose a ...	2003	12775706
identification and characterization of coenzyme b12-dependent glycerol dehydratase- and diol dehydratase-encoding genes from metagenomic dna libraries derived from enrichment cultures.	to isolate genes encoding coenzyme b(12)-dependent glycerol and diol dehydratases, metagenomic libraries from three different environmental samples were constructed after allowing growth of the dehydratase-containing microorganisms present for 48 h with glycerol under anaerobic conditions. the libraries were searched for the targeted genes by an activity screen, which was based on complementation of a constructed dehydratase-negative escherichia coli strain. in this way, two positive e. coli clo ...	2003	12788698
rapid detection of campylobacter coli, c. jejuni, and salmonella enterica on poultry carcasses by using pcr-enzyme-linked immunosorbent assay.	contamination of retail poultry by campylobacter spp. and salmonella enterica is a significant source of human diarrheal disease. isolation and identification of these microorganisms require a series of biochemical and serological tests. in this study, campylobacter ceue and salmonella inva genes were used to design probes in pcr-enzyme-linked immunosorbent assay (elisa), as an alternative to conventional bacteriological methodology, for the rapid detection of campylobacter jejuni, campylobacter ...	2003	12788755
controlled clinical comparison of bact/alert standard aerobic medium with bactec standard aerobic medium for culturing blood.	standard aerobic media are widely used for culturing blood with the bact/alert (biomérieux, inc., durham, n.c.) (bm) and bactec 9240 (bd diagnostic systems, sparks, md.) (bd) automated continuously monitoring instrument systems. although similarly composed of soybean-casein digest broths, the formulations of the standard aerobic media available for these instruments differ from each other in supplements and in sodium polyanetholesulfonate concentration. therefore, we compared the standard aerobi ...	2003	12791854
dissemination of shv-12 and characterization of new ampc-type beta-lactamase genes among clinical isolates of enterobacter species in korea.	to determine the prevalence and genotype of an extended-spectrum beta-lactamase and new chromosomal ampc beta-lactamases among clinical isolates of enterobacter species, we performed antibiotic susceptibility testing, pi determination, induction tests, transconjugation, enterobacterial repetitive consensus (eric) pcr, sequencing, and phylogenetic analysis. among the 51 clinical isolates collected from a university hospital in korea, 6 isolates have been shown to produce shv-12 and inducible ampc ...	2003	12791868
bioactivity of secoiridoid glycosides from centaurium erythraea.	as part of our on-going search for bioactive compounds from scottish plants, two secoiridoid glycosides, swertiamarin and sweroside, have been isolated from the aerial parts of centaurium erythraea rafn (family: gentianaceae) by reversed-phase preparative hplc coupled with a photo-diode-array detector. the structures of these compounds were elucidated unambiguously by uv, fabms and extensive 1d and 2d nmr spectroscopic analyses and also by comparing experimental data with literature data. antiba ...	2003	12809366
a mechanism of covalent substrate binding in the x-ray structure of subunit k of the escherichia coli dihydroxyacetone kinase.	dihydroxyacetone (dha) kinases are homologous proteins that use different phosphoryl donors, a multiphosphoryl protein of the phosphoenolpyruvate-dependent carbohydrate:phosphotransferase system in bacteria, atp in animals, plants, and some bacteria. the dha kinase of escherichia coli consists of three subunits, dhak and dhal, which are colinear to the atp-dependent dha kinases of eukaryotes, and the multiphosphoryl protein dham. here we show the crystal structure of the dhak subunit in complex ...	2003	12813127
production of cellulose and curli fimbriae by members of the family enterobacteriaceae isolated from the human gastrointestinal tract.	citrobacter spp., enterobacter spp., and klebsiella spp. isolated from the human gut were investigated for the biosynthesis of cellulose and curli fimbriae (csg). while citrobacter spp. produced curli fimbriae and cellulose and enterobacter spp. produced cellulose with various temperature-regulatory programs, klebsiella spp. did not show pronounced expression of those extracellular matrix components. investigation of multicellular behavior in two citrobacter species and enterobacter sakazakii sh ...	2003	12819107
[continuous surveillance of antimicrobial resistance among nosocomial gram-negative bacilli from intensive care units in china].	to investigate the change of antimicrobial resistance among nosocomial gram-negative bacilli, especially those of enterobacteriaceae isolated from intensive care units from 1994 to 2001 in china.	2003	12820912
survey of plasmid-associated genetic markers in enterobacteriaceae with reduced susceptibilities to cephalosporins.	clinical isolates of enterobacteriaceae with reduced susceptibilities to cephalosporins were collected from 1993 to 2000. the organisms were screened for the extended-spectrum beta-lactamase (esbl) phenotype, and plasmid extracts were screened for genetic markers by hybridization. a bla(tem) probe was derived from puc19; other probes were derived from pacm1, the plasmid responsible for the first known appearance of an esbl in our institution. these probes included bla(shv), int, aac(3)-ia, dfra1 ...	2003	12821465
evaluation of a new chromogenic medium, uriselect 4, for the isolation and identification of urinary tract pathogens.	to compare the performance of a new chromogenic medium, uriselect 4, with cystine lactose electrolyte deficient (cled) agar and an established chromogenic agar, cps id 2 medium, for detection of urinary tract pathogens.	2003	12835299
molecular epidemiology and characterization of plasmid-encoded beta-lactamases produced by tunisian clinical isolates of salmonella enterica serotype mbandaka resistant to broad-spectrum cephalosporins.	we studied 31 clinical isolates of salmonella enterica serotype mbandaka resistant to broad-spectrum cephalosporins and recovered in tunisia over a 5-year period. the transferability of this resistance was demonstrated by conjugation experiments. thirty of the 31 isolates were positive in the double-disk synergy test. by isoelectric focusing analysis, all of the isolates were found to produce a band of beta-lactamase activity with a pi of 5.9. three of these isolates produced an additional band ...	2003	12843024
comparison of four antimicrobial susceptibility testing methods to determine the in vitro activities of piperacillin and piperacillin-tazobactam against clinical isolates of enterobacteriaceae and pseudomonas aeruginosa.	susceptibility to piperacillin was similar to that to piperacillin-tazobactam (<1% difference) for 6,938 isolates of enterobacter aerogenes and 13,954 isolates of enterobacter cloacae tested using a vitek system; for the same species, in contrast, susceptibility rates to piperacillin-tazobactam were 5.9 to 13.9% higher than to piperacillin using disk diffusion, microscan, and vitek 2 testing. unprecedented phenotypes (piperacillin susceptible and piperacillin-tazobactam intermediate; piperacilli ...	2003	12843088
sequence of the escherichia coli o121 o-antigen gene cluster and detection of enterohemorrhagic e. coli o121 by pcr amplification of the wzx and wzy genes.	the dna sequence of the 15,155-bp o-antigen gene cluster of escherichia coli o121 was determined, and 14 open reading frames were identified (all had the same transcriptional direction). analyses of results indicated that the wzx (o-antigen flippase) and wzy (o-antigen polymerase) genes were e. coli o121 specific, so regions in these two genes were chosen for development of pcr assays. the pcr assays using dna from 99 e. coli o121 strains, strains representative of non-o121 e. coli serogroups, a ...	2003	12843098
virulence of enteropathogenic escherichia coli, a global pathogen.	enteropathogenic escherichia coli (epec) remains an important cause of diarrheal disease worldwide. research into epec is intense and provides a good virulence model of other e. coli infections as well as other pathogenic bacteria. although the virulence mechanisms are now better understood, they are extremely complex and much remains to be learnt. the pathogenesis of epec depends on the formation of an ultrastructural lesion in which the bacteria make intimate contact with the host apical enter ...	2003	12857773
in vitro and in vivo activities of novel 2-(thiazol-2-ylthio)-1beta-methylcarbapenems with potent activities against multiresistant gram-positive bacteria.	sm-197436, sm-232721, and sm-232724 are new 1beta-methylcarbapenems with a unique 4-substituted thiazol-2-ylthio moiety at the c-2 side chain. in agar dilution susceptibility testing these novel carbapenems were active against methicillin-resistant staphylococcus aureus (mrsa) and staphylococcus epidermidis (mrse) with a mic(90) of </=4 micro g/ml. furthermore, sm-232724 showed strong bactericidal activity against mrsa, in contrast to linezolid, which was bacteriostatic up to four times the mic. ...	2003	12878507
plasmid-mediated high-level resistance to aminoglycosides in enterobacteriaceae due to 16s rrna methylation.	a self-transferable plasmid of ca. 80 kb, pip1204, conferred multiple-antibiotic resistance to klebsiella pneumoniae bm4536, which was isolated from a urinary tract infection. resistance to beta-lactams was due to the bla(tem1) and bla(ctx-m) genes, resistance to trimethroprim was due to the dhfrxii gene, resistance to sulfonamides was due to the sul1 gene, resistance to streptomycin-spectinomycin was due to the ant3"9 gene, and resistance to nearly all remaining aminoglycosides was due to the a ...	2003	12878520
extended-spectrum beta-lactamases in ireland, including a novel enzyme, tem-102.	organisms producing extended-spectrum beta-lactamases (esbls) have been reported in many countries, but there is no information on the prevalence of esbl-producing members of the family enterobacteriaceae in ireland. a total of 925 isolates of ampicillin-resistant members of the enterobacteriaceae were received from six hospitals in ireland over a 3-year period from september 1996 to september 1999. isolates were screened for esbl production by the double-disk diffusion (ddd) method. ddd-positiv ...	2003	12878521
in vitro activities of novel oxapenems, alone and in combination with ceftazidime, against gram-positive and gram-negative organisms.	four novel oxapenem compounds (i.e., am-112, am-113, am-114, and am-115) were investigated for their beta-lactamase inhibitory activity against a panel of isolated class a, c, and d enzymes, which included expanded-spectrum beta-lactamase enzymes (esbls). the oxapenems were potent beta-lactamase inhibitors. activity varied within the group, with am-113 and am-114 proving to be the most active compounds. the 50% inhibitory concentrations for these agents were up to 100,000-fold lower than that of ...	2003	12878527
effects of a chlorhexidine gluconate-containing mouthwash on the vitality and antimicrobial susceptibility of in vitro oral bacterial ecosystems.	oral bacterial microcosms, established using saliva inocula from three individuals, were maintained under a feast-famine regime within constant-depth film fermenters. steady-state communities were exposed four times daily, postfeeding, to a chlorhexidine (chx) gluconate-containing mouthwash (chxm) diluted to 0.06% (wt/vol) antimicrobial content. the microcosms were characterized by heterotrophic plate counts and pcr-denaturing gradient gel electrophoresis (dgge). chxm caused significant decrease ...	2003	12902270
comparison and evaluation of osiris and sirscan 2000 antimicrobial susceptibility systems in the clinical microbiology laboratory.	the osiris and sirscan 2000 systems are two semiautomated systems that can be used to read and interpret the results on disk diffusion agar plates. they are both used for determination of susceptibility to antimicrobial agents. the present study compared both systems versus the nccls standard method of visual reading with a ruler. both inpatient and outpatient samples with a total of 315 nonfastidious gram-negative strains were obtained. in total, 3724 organism-antimicrobial agent combinations t ...	2003	12904366
rapid identification of bacteria from positive blood cultures by terminal restriction fragment length polymorphism profile analysis of the 16s rrna gene.	bacteremia results in significant morbidity and mortality, especially among patient populations that are immunocompromised. broad-spectrum antibiotics are administered to patients suspected to have bloodstream infections that are awaiting diagnosis that depends on blood culture analysis. significant delays in identification of pathogens can result, primarily due to the dependence on growth-based identification systems. to address these limitations, we took advantage of terminal restriction fragm ...	2003	12904391
identification of the hypervirulent lineages of neisseria meningitidis, the st-8 and st-11 complexes, by using monoclonal antibodies specific to nmedi.	most cases of serogroup c meningococcal disease are caused by the clonal lineages st-8 and st-11. the gene encoding the putative restriction-modification system nmedi is specific to these lineages. we report here a monoclonal antibody directed against the nmedi endonuclease as a tool for their rapid and spe-cific identification.	2003	12904407
modification of the double-disk test for detection of enterobacteriaceae producing extended-spectrum and ampc beta-lactamases.	detection of extended-spectrum beta-lactamases (esbls) in ampc-producing enterobacteriaceae is problematic. a modification of the double-disk test (mddt) has been developed for successful detection of esbls in gram-negative bacilli producing well-characterized beta-lactamases as well as 212 clinical isolates of enterobacter cloacae, enterobacter aerogenes, serratia marcescens, and citrobacter freundii. mddt accurately differentiated between esbl producers and derepressed chromosomal ampc mutants ...	2003	12904422
composition, acquisition, and distribution of the vi exopolysaccharide-encoding salmonella enterica pathogenicity island spi-7.	vi capsular polysaccharide production is encoded by the viab locus, which has a limited distribution in salmonella enterica serovars. in s. enterica serovar typhi, viab is encoded on a 134-kb pathogenicity island known as spi-7 that is located between partially duplicated trna(pheu) sites. functional and bioinformatic analysis suggests that spi-7 has a mosaic structure and may have evolved as a consequence of several independent insertion events. analysis of viab-associated dna in vi-positive s. ...	2003	12923078
serum bactericidal activity of trovafloxacin, in combination with cefepime or amikacin, in healthy volunteers.	to investigate the phamacokinetics and serum bactericidal activities (sbas) of trovafloxacin, cefepime and amikacin alone and trovafloxacin in combination with cefepime or amikacin, so that the most favorable combination with trovafloxacin can be determined.	2003	12925107
evaluation of increased incubation temperature and cefixime-tellurite treatment for the isolation of escherichia coli o157:h7 from minced beef.	to improve enrichment and isolation of escherichia coli o157:h7, this study evaluated increased incubation temperature and cefixime-tellurite (ct) on five strains of each of the following bacteria, e. coli, hafnia alvei, enterobacter spp., citrobacter freundii and e. coli o157:h7, and two strains of e. coli o157:nh7. these were grown in pure culture in lst broth with varying cefixime-tellurite concentrations. a range of incubation temperatures from 37 to 46 degrees c was investigated for the inh ...	2003	12927704
outcome of antibiotic therapy for third-generation cephalosporin-resistant gram-negative bacteraemia: an analysis of 249 cases caused by citrobacter, enterobacter and serratia species.	two hundred and forty-nine patients with monomicrobial bacteraemia due to third-generation cephalosporin (tgc)-resistant citrobacter freundii (42), e. aerogenes (23), e. cloacae (143), and serratia marcescens (41) were analyzed for antibiotic therapy used and outcome. for isolates with resistance to any of the tgcs, all beta-lactams, except imipenem, were considered ineffective. of 152 patients given appropriate treatment, the mortality rates were 10.9% for 128 patients given monotherapy and 25. ...	2003	12927949
keratocyte phenotype mediates proteoglycan structure: a role for fibroblasts in corneal fibrosis.	in pathological corneas, accumulation of fibrotic extracellular matrix is characterized by proteoglycans with altered glycosaminoglycans that contribute to the reduced transparency of scarred tissue. during wound healing, keratocytes in the corneal stroma transdifferentiate into fibroblasts and myofibroblasts. in this study, molecular markers were developed to identify keratocyte, fibroblast, and myofibroblast phenotypes in primary cultures of corneal stromal cells and the structure of glycosami ...	2003	12933807
extended-spectrum beta-lactamases in enterobacteriaceae in buenos aires, argentina, public hospitals.	resistance to extended-spectrum cephalosporins is often associated with plasmid encoded extended spectrum beta-lactamases (esbl). in order to evaluate the prevalence and diversity of esbls in enterobacteria in our city, a 1-month-period survey was carried out from april to may 2000. extended-spectrum-cephalosporin-resistant strains, isolated from inpatient clinical specimens other than stools, were collected among 17 participating hospitals. from a total of 427 enterobacterial strains that were ...	2003	12936986
epidemiological risk factors for isolation of ceftriaxone-resistant versus -susceptible citrobacter freundii in hospitalized patients.	antimicrobial resistance is an emerging problem among nosocomial bacteria. risk factors for the recovery of ceftriaxone-resistant (crcf) or -susceptible (cscf) citrobacter freundii in clinical cultures from hospitalized patients were determined by using a case-case-control study design. crcf was isolated from 43 patients (case group 1) and cscf was isolated from 87 patients (case group 2) over a 3-year period. risk factors for crcf were exposure to imipenem (odds ratio [or], 7.5; 95% confidence ...	2003	12936989
insertion sequence isecp1b is involved in expression and mobilization of a bla(ctx-m) beta-lactamase gene.	the genetic structures (ca. 10-kb dna fragment) surrounding the plasmid-borne extended-spectrum beta-lactamase bla(ctx-m-19) gene in a klebsiella pneumoniae clinical isolate were determined. this beta-lactamase gene was part of a 4,797-bp transposon inserted inside orf1 of tn1721. inside this transposon, bla(ctx-m-19) was bracketed upstream and downstream by insertion sequences ise cp1b and is903d, respectively, and further downstream by a truncated gene encoding an outer membrane protein for ir ...	2003	12936998
moritella cold-active dihydrofolate reductase: are there natural limits to optimization of catalytic efficiency at low temperature?	adapting metabolic enzymes of microorganisms to low temperature environments may require a difficult compromise between velocity and affinity. we have investigated catalytic efficiency in a key metabolic enzyme (dihydrofolate reductase) of moritella profunda sp. nov., a strictly psychrophilic bacterium with a maximal growth rate at 2 degrees c or less. the enzyme is monomeric (mr=18,291), 55% identical to its escherichia coli counterpart, and displays tm and denaturation enthalpy changes much lo ...	2003	12949104
kinetic studies on endo-beta-galactosidase by a novel colorimetric assay and synthesis of n-acetyllactosamine-repeating oligosaccharide beta-glycosides using its transglycosylation activity.	novel chromogenic substrates for endo-beta-galactosidase were designed on the basis of the structural features of keratan sulfate. galbeta1-4glcnacbeta1-3galbeta1-4glcnacbeta-pnp (2), which consists of two repeating units of n-acetyllactosamine, was synthesized enzymatically by consecutive additions of glcnac and gal residues to p-nitrophenyl beta-n-acetyllactosaminide. in a similar manner, glcnacbeta1-3galbeta1-4glcnacbeta-pnp (1), glcnacbeta1-3galbeta1-4glcbeta-pnp (3), galbeta1-4glcnacbeta1-3 ...	2003	12950254
growth of escherichia coli in model distribution system biofilms exposed to hypochlorous acid or monochloramine.	bacteria indigenous to water distribution systems were used to grow multispecies biofilms within continuous-flow slide chambers. six flow chambers were also inoculated with an escherichia coli isolate obtained from potable water. the effect of disinfectants on bacterial populations was determined after exposure of established biofilms to 1 ppm of hypochlorous acid (cloh) for 67 min or 4 ppm of monochloramine (nh(2)cl) for 155 min. to test the ability of bacterial populations to initiate biofilm ...	2003	12957935
antibody responses to escherichia coli o157 and other lipopolysaccharides in healthy children and adults.	in mexico, diarrheal disease due to different serotypes of escherichia coli is highly prevalent, with only sporadic isolation of o157 non-h7 strains. this could be due to exposure to the o157 or related e. coli lipopolysaccharide (lps), such as o7 or o116, at an early age. by using enzyme-linked immunosorbent assay (elisa) and western blotting, the present study analyzed 605 serum samples from mexican adults and infants without clinical symptoms of disease for the presence of antibodies to these ...	2003	12965907
crystal structure of the citrobacter freundii dihydroxyacetone kinase reveals an eight-stranded alpha-helical barrel atp-binding domain.	dihydroxyacetone kinases are a sequence-conserved family of enzymes, which utilize two different phosphoryldonors, atp in animals, plants and some bacteria, and a multiphosphoprotein of the phosphoenolpyruvate carbohydrate phosphotransferase system in bacteria. here we report the 2.5-a crystal structure of the homodimeric citrobacter freundii dihydroxyacetone kinase complex with an atp analogue and dihydroxyacetone. the n-terminal domain consists of two alpha/beta-folds with a molecule of dihydr ...	2003	12966101
interconversion of isocitrate and alpha-ketoglutarate by escherichia freundii.		1953	13069468
an escherichia freundii strain related to escherichia coli 111:b4.		1953	13079820
[intestinal coliform flora of native lizards in relation to the bacteriological evaluation of drinking water; with a contribution to the bacteriology of escherichia freundii].		1954	13196449
a culture of escherichia freundii serologically related to the genus salmonella.		1954	13221557
[agglutinin formation by various protein fractions of salmonella ballerup].		1955	13262015
the characterization of hyaluronidase isolated from escherichia freundii.		1958	13538968
[escherichia freundii with complete salmonella takoradi antigens in a case of diarrhea].		1958	13579507
[studies on escherichia freundii strains carrying the vi antigen and their place in the escherichia freundii group].		1959	13627589
[comparative study of escherichia freundii & salmonella strains].		1959	13670527
enhancement of plasmid curing by 9-aminoacridine and two phenothiazines in the presence of proton pump inhibitor 1-(2-benzoxazolyl)-3,3,3-trifluoro-2-propanone.	plasmid-containing bacteria often cause serious therapeutic failure during the treatment of infectious diseases. the selection of resistant-mutant strains and the transfer of mobile genetic determinants (such as plasmids and transposons) of resistance promote increased antibiotic resistance. in the last 30 years the antiplasmid effect of acridine dyes, ethidium bromide, sodium dodecyl sulphate and phenothiazines was described. the main aim of this study was to test the mechanism of the antiplasm ...	2003	13678825
[paracoli bethesda (citrobacter) and escherichia freundii in disease in dakar].		1959	13797825
[the radiosensitivity of escherichia freundii cultures as a function of the intra- and extracellular accumulation of citrate produced by the addition of fluoroacetate to the culture medium].		1963	13930516
[x-ray induction of the destruction of desoxyribonucleic acid from escherichia freundii. 1. influence of the composition of the irradiation and incubation medium].		1963	13940593
[induction by x-rays of the destruction of deoxyribonucleic acid from escherichia freundii. 2. study of various conditions capable of modifying this destruction].		1963	13940594
isolation of n-acetylneuraminic acid and 4-oxonorleucine from a polysaccharide obtained from citrobacter freundii.		1963	14072840
synthesis of 4-oxonorleucine and comparison with an amino acid isolated from citrobacter freundii.		1964	14189890
endocarditis due to escherichia freundii and staphylococcus aureus.		1965	14232586
citrobacter freundii associated with diarrhea in a laboratory mice.		1965	14341174
[radio-sensitivity of cultures of escherichia freundii cultivated in the presence of fluoroacetate].		1965	14345641
[conditioned hemagglutination (salmonella ballerup): inhibiting power of normal sera, of sera with extracted lipids and of serum lipids on the fixation of antigens by erythrocytes].		1955	14389467
[study of escherichia freundii and considerations on their taxonomic position].		1955	14389477
escherichia freundii meningitis. report of two cases.		1960	14399934
3-hydroxy bile acid dehydrogenase from escherichia freundii.		1960	14400286
[change in the radiosensitivity of escherichia freundii cultured in the presence of fluoroacetate].		1962	14465158
development of a rapid 1-h fluorescence-based cytotoxicity assay for listeria species.	listeria monocytogenes is cytotoxic to the lymphocyte-origin hybridoma ped-2e9 cell line. the relative cytotoxicity can be calculated by assaying the release of alkaline phosphatase (alp) from the infected cell line. in this study, a fluorogenic substrate (4-methylumbelliferyl phosphate, mup) was used to quantify the alp activity. the assay is 3.5-fold more sensitive than the colorimetric-based assay and requires only 1 h to differentiate virulent from avirulent strains. in addition to various l ...	2003	14499993
in vitro antibacterial potency and spectrum of abt-492, a new fluoroquinolone.	abt-492 demonstrated potent antibacterial activity against most quinolone-susceptible pathogens. the rank order of potency was abt-492 > trovafloxacin > levofloxacin > ciprofloxacin against quinolone-susceptible staphylococci, streptococci, and enterococci. abt-492 had activity comparable to those of trovafloxacin, levofloxacin, and ciprofloxacin against seven species of quinolone-susceptible members of the family enterobacteriaceae, although it was less active than the comparators against citro ...	2003	14506039
identifying antimicrobial resistance genes with dna microarrays.	we developed and tested a glass-based microarray suitable for detecting multiple tetracycline (tet) resistance genes. microarray probes for 17 tet genes, the beta-lactamase bla(tem-1) gene, and a 16s ribosomal dna gene (escherichia coli) were generated from known controls by pcr. the resulting products (ca. 550 bp) were applied as spots onto epoxy-silane-derivatized, teflon-masked slides by using a robotic spotter. dna was extracted from test strains, biotinylated, hybridized overnight to indivi ...	2003	14506043
mutational analysis of the catalytic centre of the citrobacter freundii ampd n-acetylmuramyl-l-alanine amidase.	citrobacter freundii ampd is an intracellular 1,6-anhydro-n-acetylmuramyl-l-alanine amidase involved in both peptidoglycan recycling and beta-lactamase induction. ampd exhibits a strict specificity for 1,6-anhydromuropeptides and requires zinc for enzymic activity. the ampd three-dimensional structure exhibits a fold similar to that of another zn2+ n-acetylmuramyl-l-alanine amidase, the t7 lysozyme, and these two enzymes define a new family of zn-amidases which can be related to the eukaryotic p ...	2004	14507260
sepsis in a renal transplant recipient due to citrobacter braakii.	cellulitis is usually caused by organisms such as beta-hemolytic streptococci and staphylococcus aureus. citrobacter are gram-negative bacilli that can cause opportunistic infections in immunocompromised hosts. they are rarely implicated in skin or soft tissue infections. the genus citrobacter has been respeciated according to genetic relatedness. citrobacter braakii refers to the genomospecies 6 of the citrobacter freundii complex. there are no detailed studies of infections caused by the newly ...	2003	14515921
multiplex real-time pcr method to identify shiga toxin genes stx1 and stx2 and escherichia coli o157:h7/h- serotype.	a multiplex real-time pcr method to simultaneously detect the stx1 and stx2 genes of shiga toxin-producing escherichia coli and a unique conserved single-nucleotide polymorphism in the e. coli o157:h7/h- uida gene has been developed. there is more than 98.6% sensitivity and 100% specificity for all three gene targets based on a panel of 138 isolates. the pcr efficiencies were >/= 1.89, and as few as 6 cfu/reaction could be detected.	2003	14532101
association between handling of pet treats and infection with salmonella enterica serotype newport expressing the ampc beta-lactamase, cmy-2.	resistance to the extended-spectrum cephalosporins can occur in salmonella species via the production of extended-spectrum and ampc beta-lactamases. we describe human infections with salmonella enterica serotype newport phage type 14 strains resistant to ceftazidime (caz) and cefoxitin (fox) related to the handling of pet treats containing dried beef. these strains were isolated from five patients in calgary, alberta, canada, during 2002 and were compared to a strain cultured from a commercial p ...	2003	14532185
algorithm to determine cost savings of targeting antimicrobial therapy based on results of rapid diagnostic testing.	a rapid diagnosis of pneumococcal pneumonia may allow the earlier use of narrow-spectrum antimicrobial therapy. it is unknown, however, whether rapid diagnostic testing of patients hospitalized with community-acquired pneumonia (cap) admitted to hospital lowers costs. therefore, an algorithm to calculate the costs associated with the diagnosis and treatment of cap was formulated. subsequently, the algorithm was applied to clinical data for 122 consecutively admitted patients with cap whose sputu ...	2003	14532208
detection of yersinia pestis in sputum by real-time pcr.	a 5' nuclease pcr assay for detection of the yersinia pestis plasminogen activator (pla) gene in human respiratory specimens with simulated y. pestis infection was developed. an internal positive control was added to the reaction mixture in order to detect the presence of pcr inhibitors that are often found in biological samples. the assay was 100% specific for y. pestis. in the absence of inhibitors, a sensitivity of 10(2) cfu/ml of respiratory fluid was obtained. when inhibitors were present, ...	2003	14532247
tempe fermentation: some aspects of formation of gamma-linolenic acid, proteases and vitamins.	during a tempe fermentation the concentrations of linoleic, and alpha-linolenic acids (ala) decreased while the concentration of oleic acid increased. during fatty acid synthesis rhizopus sp. produced only gamma-linolenic acid (gla) instead of ala. the amount of gla in tempe were influenced by varying external parameters. the proteolytic capacity of 36 strains of the genus rhizopus isolated from indonesian tempe or tempe inocula was examined. there was a distinct increase in the amount of free a ...	1993	14545670
resistance to extended-spectrum cephalosporins and mortality in patients with citrobacter freundii bacteremia.	this study was performed to characterize the clinical features and to identify the risk factors for resistance to extended-spectrum cephalosporins (escs) and for mortality in patients with citrobacter freundii bacteremia.	2003	14562942
[yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2001--ii. gram-negative bacteria].	the in vitro antibacterial activities of cefozopran (czop), an agent of cephems, against various clinical isolates obtained between 1996 and 2001 were yearly evaluated and compared with those of other cephems, oxacephems and carbapenems. a total of 3,245 strains in 32 species of gram-negative bacteria were isolated from the clinical materials annually collected from january to december, and consisted of moraxella subgenus branhamella catarrhalis, escherichia coli, citrobacter freundii, citrobact ...	2003	14567255
effects of triclosan-containing rinse on the dynamics and antimicrobial susceptibility of in vitro plaque ecosystems.	dental plaque microcosms were established under a feast-famine regimen within constant-depth film fermentors and exposed four times daily postfeeding to a triclosan (tr)-containing rinse (dentifrice) (trd). this was diluted so that the antimicrobial content was 0.6 mg/ml. microcosms were characterized by heterotrophic plate counts and pcr-denaturing gradient gel electrophoresis (dgge) with primers specific for the v2-v3 region of the eubacterial 16s rrna gene (rdna). dominant isolates and pcr am ...	2003	14576113
functional profiling of mercuric reductase (mer a) genes in biofilm communities of a technical scale biocatalyzer.	bacterial mercury resistance is based on enzymatic reduction of ionic mercury to elemental mercury and has recently been demonstrated to be applicable for industrial wastewater clean-up. the long-term monitoring of such biocatalyser systems requires a cultivation independent functional community profiling method targeting the key enzyme of the process, the mera gene coding for the mercuric reductase. we report on the development of a profiling method for mera and its application to monitor chang ...	2003	14577839
use of o-antigen gene cluster-specific pcrs for the identification and o-genotyping of yersinia pseudotuberculosis and yersinia pestis.	yersinia pestis is a very recently evolved clone of yersinia pseudotuberculosis serotype o:1b. this close relationship causes potential difficulties in dna-based diagnostic methods. analysis of the o-antigen gene clusters in these two organisms identified two regions that were used to specifically identify y. pestis-y. pseudotuberculosis as a group or y. pestis alone. both pcr assays were found to be 100% specific when tested on a large collection of yersinia species and other enterobacteriaceae ...	2003	14605146
application of an rrna probe matrix for rapid identification of bacteria and fungi from routine blood cultures.	one of the most important functions of the clinical microbiology laboratory is the identification of the etiology of sepsis. for this study, aliquots from 405 positive blood cultures were tested against a unique array of dna probes directed against rrna subsequences of bacteria and fungi for identification. another 280 samples that were negative after 5 days of incubation were also tested. blood culture bottles were incubated in a bact/alert3d instrument. for the rrna assay, a 0.4-ml aliquot was ...	2003	14605149
escherichia coli o157 exposure in wyoming and seattle: serologic evidence of rural risk.		2003	14609456
cephamycin resistance in clinical isolates and laboratory-derived strains of escherichia coli, nova scotia, canada.		2003	14609460
antimicrobial resistance in gram-negative bacilli isolated from infant formulas.	a total of 90 samples of infant formula (if) were collected from the lactary of a teaching hospital, during a 4-month period from july to august 1999. the sanitary conditions of the formulas were analyzed, and a physiological characterization of gram-negative bacillus isolates and antimicrobial susceptibility testing were performed. colony counts were considered to be unacceptable for the majority of the if samples and the contamination rates were related to inadequate handling. coliforms (35 de ...	2003	14638421
prevalence and molecular epidemiology of ctx-m extended-spectrum beta-lactamase-producing escherichia coli and klebsiella pneumoniae in russian hospitals.	a total of 904 consecutive nosocomial isolates of escherichia coli and klebsiella pneumoniae collected from 28 russian hospitals were screened for production of extended-spectrum beta-lactamases (esbls). the esbl phenotype was detected in 78 (15.8%) e. coli and 248 (60.8%) k. pneumoniae isolates. one hundred fifteen isolates carried the genes for ctx-m-type beta-lactamases, which, as shown by pcr-restriction fragment length polymorphism analysis, were distributed into the two genetic groups of c ...	2003	14638473
genehunter, a transposon tool for identification and isolation of cryptic antibiotic resistance genes.	genehunter is a transposon tool designed for the experimental activation and identification of silent antibiotic resistance genes. the method permits the identification of novel resistance genes that lack previously identified homologues. using salmonella enterica serovar typhimurium strain lt2 as a test organism for the in vivo version of the genehunter method, we were able to activate, clone, and identify two cryptic antibiotic resistance genes, the aminoglycoside acetyltransferase aac(6')-iaa ...	2003	14638492
carbapenem-resistant strain of klebsiella oxytoca harboring carbapenem-hydrolyzing beta-lactamase kpc-2.	we investigated a klebsiella oxytoca isolate demonstrating resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. the mics of both imipenem and meropenem were 32 microg/ml. the beta-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. isoelectric focusing studies demonstrated five beta-lactamases with pis of 8.2 (shv-46), 6.7 (kpc-2), 6.5 (unknown), 6.4 (probable oxy-2), and 5.4 (tem-1). the presence of the bla(shv) and ...	2003	14638498
molecular epidemiology of orf513-bearing class 1 integrons in multiresistant clinical isolates from argentinean hospitals.	the spread of orf513-bearing class 1 integrons is associated with bla(ctx-m-2) in gram-negative clinical isolates in argentina, with in35 being the most frequently found integron (74%). among 65 isolates without bla(ctx-m-2), only one harbored a novel orf513-bearing class 1 integron with the dfra3b gene. the finding of orf513 not associated with class 1 integrons in two gram-positive strains indicates the widespread occurrence of this putative site-specific recombinase.	2003	14638506
a molecular phylogeny of enteric bacteria and implications for a bacterial species concept.	a molecular phylogeny for seven taxa of enteric bacteria (citrobacter freundii, enterobacter cloacae, escherichia coli, hafnia alvei, klebsiella oxytoca, klebsiella pneumoniae, and serratia plymuthica) was made from multiple isolates per taxa taken from a collection of environmental enteric bacteria. sequences from five housekeeping genes (gapa, groel, gyra, ompa, and pgi) and the 16s rrna gene were used to infer individual gene trees and were concatenated to infer a composite molecular phylogen ...	2003	14640415
mutagenesis of suge, a small multidrug resistance protein.	the small multidrug resistance protein family has two subclasses. in this study we used a mutation approach to see what is necessary to convert a sug subgroup member into a quaternary ammonium compound (qac) transporter. we chose four key residues (h24, m39, i43, and a44) conserved within sugs but conserved differently within the qac transporters. altogether, seven mutants were generated in citrobacter freundii suge. surprisingly, the mutated suge demonstrated an increased sensitivity to represe ...	2003	14651958
protein identification from two-dimensional gel electrophoresis analysis of klebsiella pneumoniae by combined use of mass spectrometry data and raw genome sequences.	separation of proteins by two-dimensional gel electrophoresis (2-de) coupled with identification of proteins through peptide mass fingerprinting (pmf) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (maldi-tof ms) is the widely used technique for proteomic analysis. this approach relies, however, on the presence of the proteins studied in public-accessible protein databases or the availability of annotated genome sequences of an organism. in this work, we investig ...	2003	14653859
transduction of porcine enteropathogenic escherichia coli with a derivative of a shiga toxin 2-encoding bacteriophage in a porcine ligated ileal loop system.	in this study, we have investigated the ability of detoxified shiga toxin (stx)-converting bacteriophages phi3538 (deltastx(2)::cat) (h. schmidt et al., appl. environ. microbiol. 65:3855-3861, 1999) and h-19b::tn10d-bla (d. w. acheson et al., infect. immun. 66:4496-4498, 1998) to lysogenize enteropathogenic escherichia coli (epec) strains in vivo. we were able to transduce the porcine epec strain 1390 (o45) with phi3538 (deltastx(2)::cat) in porcine ligated ileal loops but not the human epec pro ...	2003	14660372
hydrolysis of third-generation cephalosporins by class c beta-lactamases. structures of a transition state analog of cefotoxamine in wild-type and extended spectrum enzymes.	bacterial resistance to the third-generation cephalosporins is an issue of great concern in current antibiotic therapeutics. an important source of this resistance is from production of extended-spectrum (es) beta-lactamases by bacteria. the enterobacter cloacae gc1 enzyme is an example of a class c es beta-lactamase. unlike wild-type (wt) forms, such as the e. cloacae p99 and citrobacter freundii enzymes, the es gc1 beta-lactamase is able to rapidly hydrolyze third-generation cephalosporins suc ...	2004	14660590
pcr typing of genetic determinants for metallo-beta-lactamases and integrases carried by gram-negative bacteria isolated in japan, with focus on the class 3 integron.	from january 2001 to december 2002, 587 strains of gram-negative bacterial isolates demonstrating resistance to ceftazidime and a combination of sulbactam and cefoperazone were subjected to a disk diffusion screening test using sodium mercaptoacetic acid; 431 strains (73.4%) appeared to produce metallo-beta-lactamase (mbl). of these 431 strains, 357 were found by pcr to carry genes for imp-1 type mbl (bla(imp-1)), while only 7 and 67 strains carried the imp-2 gene (bla(imp-2)) and the vim-2 gene ...	2003	14662918