Publications

activation of the cryptic aac(6')-iy aminoglycoside resistance gene of salmonella by a chromosomal deletion generating a transcriptional fusion.	salmonella enterica subsp. enterica serotype enteritidis bm4361 and bm4362 were isolated from the same patient. bm4361 was susceptible to aminoglycosides, whereas bm4362 was resistant to tobramycin owing to synthesis of a 6'-n-acetyltransferase type i [aac(6')-i]. comparative analysis of nucleotide sequences, pulsed-field gel electrophoresis patterns, and southern hybridizations indicated that the chromosomal aac(6')-iy genes for the enzyme in both strains were identical and that bm4362 derived ...	1999	10542165
application of a dna hybridization-hydrophobic-grid membrane filter method for detection and isolation of verotoxigenic escherichia coli.	verotoxigenic escherichia coli (vtec) strains were isolated from food and animal fecal samples by using pcr to screen for the presence of vtec after broth enrichment and then filtering vtec-positive cultures through hydrophobic-grid membrane filters (hgmfs) which were incubated on macconkey agar. the filters were probed with a digoxigenin-labeled pcr product generated by amplification of a conserved verotoxin gene sequence. replication of the growth on filters allowed probe-positive colonies to ...	1999	10543785
phylogenetic diversity of nitrogen fixation genes in the symbiotic microbial community in the gut of diverse termites.	nitrogen fixation by the microorganisms in the gut of termites is one of the crucial aspects of symbiosis, since termites usually thrive on a nitrogen-poor diet. the phylogenetic diversity of the nitrogen-fixing organisms within the symbiotic community in the guts of various termite species was investigated without culturing the resident microorganisms. a portion of the dinitrogenase reductase gene (nifh) was directly amplified from dna extracted from the mixed population in the termite gut. ana ...	1999	10543805
screening of probiotic activities of forty-seven strains of lactobacillus spp. by in vitro techniques and evaluation of the colonization ability of five selected strains in humans.	the probiotic potential of 47 selected strains of lactobacillus spp. was investigated. the strains were examined for resistance to ph 2.5 and 0.3% oxgall, adhesion to caco-2 cells, and antimicrobial activities against enteric pathogenic bacteria in model systems. from the results obtained in vitro, five strains, lactobacillus rhamnosus 19070-2, l. reuteri dsm 12246, l. rhamnosus lgg, l. delbrueckii subsp. lactis chcc 2329, and l. casei subsp. alactus chcc 3137, were selected for in vivo studies. ...	1999	10543808
development of a universal intimin antiserum and pcr primers.	enteropathogenic escherichia coli (epec) and enterohemorrhagic e. coli (ehec) constitute a significant risk to human health worldwide. a hallmark of both pathogens is their ability to produce characteristic attaching-and-effacing (a/e) lesions in intestinal epithelial cells. genes encoding a/e lesion formation map to a chromosomal pathogenicity island termed the locus of enterocyte effacement (lee). intimin, an lee-encoded bacterial adhesion molecule, mediates the intimate bacterium-host cell in ...	1999	10565891
bacteremia due to extended-spectrum beta-lactamase-producing escherichia coli and klebsiella pneumoniae in a pediatric oncology ward: clinical features and identification of different plasmids carrying both shv-5 and tem-1 genes.	thirteen patients who had 16 episodes of bacteremia were observed between 1993 and 1997 in a pediatric oncology ward with a high background isolation rate of cefotaxime- or aztreonam-resistant gram-negative bacteria. four blood isolates were escherichia coli and 12 were klebsiella pneumoniae, and these isolates harbored extended-spectrum beta-lactamases (esbls). all episodes of bacteremia were nosocomial, all except one of the episodes occurred in neutropenic patients, and all patients were trea ...	1999	10565924
decreased adherence of enterohemorrhagic escherichia coli to hep-2 cells in the presence of antibodies that recognize the c-terminal region of intimin.	antiserum raised against intimin from enterohemorrhagic escherichia coli (ehec) o157:h7 strain 86-24 has been shown previously by our laboratory to inhibit adherence of this strain to hep-2 cells. in the present study, we sought to identify the region(s) of intimin important for the effect of anti-intimin antisera on ehec adherence and to determine whether antisera raised against intimin from an o157:h7 strain could reduce adherence of other strains. compared to preimmune serum controls, polyclo ...	1999	10569757
microtubules are associated with intracellular movement and spread of the periodontopathogen actinobacillus actinomycetemcomitans.	actinobacillus actinomycetemcomitans suny 465, the invasion prototype strain, enters epithelial cells by an actin-dependent mechanism, escapes from the host cell vacuole, and spreads intracellularly and to adjacent epithelial cells via intercellular protrusions. internalized organisms also egress from host cells into the assay medium via protrusions that are associated with just a single epithelial cell. here we demonstrate that agents which inhibit microtubule polymerization (e.g., colchicine) ...	1999	10569770
resolution of high-molecular-weight components in lipopolysaccharides of escherichia coli, morganella morganii, citrobacter freundii and citrobacter diversus strains with sodium dodecyl sulfate polyacrylamide gels.	the use of 0.5% sodium dodecyl sulfate in polyacrylamide separation gels allowed the resolution in several bands of high-molecular-mass components in smooth lipopolysaccharide of bacterial outer membrane from escherichia coli, morganella morganii, citrobacter freundii and citrobacter diversus. with or without 0.1% sds, however, such a result was not possible.	2000	10576704
multicenter evaluation of the antimicrobial activity for six broad-spectrum beta-lactams in venezuela: comparison of data from 1997 and 1998 using the etest method. venezuelan antimicrobial resistance study group.	the minimum inhibitory concentrations of six broad-spectrum beta-lactam antimicrobial agents were determined in 1998 by use of the etest versus a total of 502 bacteria in seven venezuelan hospital laboratories. these data were compared with results of a similar study performed in 1997. the organisms tested included 309 recent clinical isolates of enterobacteriaceae, 70 pseudomonas aeruginosa, 54 acinetobacter species, and 69 oxacillin-susceptible staphylococcus aureus. extended spectrum beta-lac ...	1999	10579096
activities of a nitrofurazone-containing urinary catheter and a silver hydrogel catheter against multidrug-resistant bacteria characteristic of catheter-associated urinary tract infection.	the in vitro inhibitory activity of a nitrofurazone-coated urinary catheter (nfc) against 86 recently obtained susceptible and multidrug-resistant (mdr) clinical isolates of escherichia coli, klebsiella pneumoniae, citrobacter freundii, staphylococcus aureus, coagulase-negative staphylococci, and enterococcus faecium, which are species implicated in catheter-associated urinary tract infection and which traditionally have been susceptible to nitrofuran derivatives, was determined using an agar di ...	1999	10582894
in vitro activities of sch27899 alone and in combination with 17 other antimicrobial agents.	sch27899, an everninomicin antibiotic, was tested for its in vitro activity against 718 bacterial isolates representing 27 species. the enterobacteriaceae and nonenteric gram-negative bacilli were resistant to > or = 8.0 microg/ml, but all others were inhibited by < or = 1.0 microg/ml. when tested in combination with 17 other antimicrobial agents against 110 strains, sch27899 demonstrated no significant antagonism or synergy. consequently, combination therapy is not contraindicated.	1999	10582895
concurrent outbreaks of extended-spectrum beta-lactamase-producing organisms of the family enterobacteriaceae in a warsaw hospital.	the increasing use of broader-spectrum cephalosporins in the first half of the 1990s has become one of the major factors responsible for the high rate of selection of extended-spectrum beta-lactamase (esbl)-producing microorganisms in polish hospitals. thirty-five isolates of seven different species of the family enterobacteriaceae were identified as esbl producers, over a 4 month period, in one of warsaw's hospitals between the end of 1996 and the beginning of 1997. sixteen per cent of all kleb ...	1999	10588311
analysis of the mechanisms of quinolone resistance in clinical isolates of citrobacter freundii.	the presence of gyra, gyrb and/or parc mutations, quinolone uptake, outer membrane protein profiles and epidemiological relationship were studied in 12 clinical isolates of citrobacter freundii. no alterations were observed in the gyrb gene of any of the strains, or gyra or parc of the four quinolone-susceptible strains (nalidixic acid mic of 2-4 mg/l, and a ciprofloxacin mic of 0.006-0.06 mg/l). the quinolone-resistant strains were classified into two groups: one group (group a) composed of str ...	1999	10590274
gram-negative bacillary meningitis in adult post-neurosurgical patients.	to assess the clinical features and therapeutic outcomes of gram-negative bacillary meningitis (gnbm) in adult postneurosurgical patients.	1999	10595761
comparison of five beta-lactam antibiotics against common nosocomial pathogens using the time above mic at different creatinine clearances.	to compare the time above the minimum inhibitory concentration (t>mic) for five parenteral beta-lactam antibiotics against common nosocomial bacterial pathogens at different creatinine clearances (clcr).	1999	10600088
promiscuous origin of a chimeric sequence in the escherichia coli o157:h7 genome.	a novel sequence of 2.9 kb in the intergenic region between the muts and rpos genes of escherichia coli o157:h7 and closely related strains replaces a sequence of 6.1 kb in e. coli k-12 strains. at the same locus in shigella dysenteriae type 1, a sequence identical to that in o157:h7 is bounded by the is1 insertion sequence element. extensive polymorphism in the muts-rpos chromosomal region is indicative of horizontal transfer events.	1999	10601221
role of penicillin-binding proteins in the initiation of the ampc beta-lactamase expression in enterobacter cloacae.	penicillin-binding proteins (pbps) are involved in the regulation of beta-lactamase expression by determining the level of anhydromuramylpeptides in the periplasmatic space. it was hypothesized that one or more pbps act as a sensor in the beta-lactamase induction pathway. we have performed induction studies with escherichia coli mutants lacking one to four pbps with dd-carboxypeptidase activity. therefore, we conclude that a strong beta-lactamase inducer must inhibit all dd-carboxypeptidases as ...	2000	10602741
typing of intimin genes in human and animal enterohemorrhagic and enteropathogenic escherichia coli: characterization of a new intimin variant.	enteropathogenic escherichia coli (epec) and enterohemorrhagic e. coli (ehec) produce the characteristic "attaching and effacing" (a/e) lesion of the brush border. intimin, an outer membrane protein encoded by eae, is responsible for the tight association of both pathogens with the host cell. several eae have been cloned from different epec and ehec strains isolated from humans and animals. these sequences are conserved in the n-terminal region but highly variable in the last c-terminal 280 amin ...	2000	10603369
two distinct antigenic types of the polysaccharide chains of helicobacter pylori lipopolysaccharides characterized by reactivity with sera from humans with natural infection.	we have purified lipopolysaccharides (lps) from 10 helicobacter pylori clinical isolates which were selected on the basis of chemotype and antigenic variation. data from immunoblotting of the purified lps with sera from humans with h. pylori infection and from absorption of the sera with lps indicated the presence of two distinct epitopes, termed the highly antigenic and the weakly antigenic epitopes, on the polysaccharide chains. among 68 h. pylori clinical isolates, all smooth strains possesse ...	2000	10603381
convenient test for screening metallo-beta-lactamase-producing gram-negative bacteria by using thiol compounds.	a simple disk diffusion test was constructed for detection of imp-1-type metallo-beta-lactamase-producing gram-negative bacteria. two kirby-bauer disks containing ceftazidime (caz) and a filter disk containing a metallo-beta-lactamase inhibitor were used in this test. several imp-1 inhibitors such as thiol compounds including 2-mercaptopropionic acid, heavy metal salts, and edta were evaluated for this test. two caz disks were placed on a mueller-hinton agar plate on which a bacterial suspension ...	2000	10618060
detection of clarithromycin-resistant helicobacter pylori strains by a preferential homoduplex formation assay.	it has been shown that resistance to clarithromycin, a major cause of failure in helicobacter pylori eradication therapy, is associated with point mutations in the 23s rrna gene. we sought to apply the preferential homoduplex formation assay (phfa), a novel technique for the efficient detection of point mutations, to detection of the mutations. phfa was performed on streptavidin-coated microtiter plates with biotin- and dinitrophenyl-labeled amplicons to detect the wild-type gene or each mutant ...	2000	10618089
impact of an urban effluent on antibiotic resistance of riverine enterobacteriaceae and aeromonas spp.	in order to evaluate the impact of an urban effluent on antibiotic resistance of freshwater bacterial populations, water samples were collected from the arga river (spain), upstream and downstream from the wastewater discharge of the city of pamplona. strains of enterobacteriaceae (representative of the human and animal commensal flora) (110 isolates) and aeromonas (typically waterborne bacteria) (118 isolates) were selected for antibiotic susceptibility testing. most of the aeromonas strains (7 ...	2000	10618213
intestinal protozoa in hiv-infected patients: effect of rifaximin in cryptosporidium parvum and blastocystis hominis infections.	in hiv-1 infected patients severe enteritis and chronic diarrhea are often documented as a consequence of multiple opportunistic infections. we analyzed 48 hiv-1 positive patients for the presence of intestinal pathogenic protozoa. patients with cd4 > or = 200/mm3 showed a higher prevalence of a single pathogenic protozoa than patients with cd4 < or =200/mm3, who showed the presence of multiple protozoal infections. patients who proved positive for only a single protozoa, cryptosporidium or blas ...	1999	10632386
cloning, nucleotide sequencing, and analysis of the gene encoding an ampc beta-lactamase in acinetobacter baumannii.	a clinical strain of acinetobacter baumannii (strain ab ryc 52763/97) that was isolated during an outbreak in our hospital and that was resistant to all beta-lactam antibiotics tested produced three beta-lactamases: a tem-1-type (pi, 5.4) plasmid-mediated beta-lactamase, a chromosomally mediated oxa-derived (pi, 9.0) beta-lactamase, and a presumptive chromosomal cephalosporinase (pi, 9.4). the nucleotide sequence of the chromosomal cephalosporinase gene shows for the first time the gene encoding ...	2000	10639377
decreased production of ampc-type beta-lactamases associated with the development of resistance to quinolones in citrobacter freundii strains.	the effect of fluoroquinolones in citrobacter freundii strains that results in a decreased expression of cephalosporin-hydrolysing beta-lactamases was studied. resistance to broad-spectrum cephalosporins and penicillins in two c. freundii clinical isolates was associated with moderate production of chromosomal ampc-type-beta-lactamase in addition to changes in the outer membrane proteins profile with respect to wild-type c. freundii strains. ten quinolone-resistant mutants were derived from the ...	1999	10647079
cloning, expression, and purification of a thermostable nonhomodimeric restriction enzyme, bsli.	bsli is a thermostable type ii restriction endonuclease with interrupted recognition sequence ccnnnnn/nngg (/, cleavage position). the bsli restriction-modification system from bacillus species was cloned and expressed in escherichia coli. the system is encoded by three genes: the 2,739-bp bsli methylase gene (bslim), the bsliralpha gene, and the bslirbeta gene. the alpha and beta subunits of bsli can be expressed independently in e. coli in the absence of bsli methylase (m.bsli) protection. bsl ...	2000	10648519
the sigma(70) transcription factor tyrr has zinc-stimulated phosphatase activity that is inhibited by atp and tyrosine.	the tyrr protein of escherichia coli (513 amino acid residues) is the chief transcriptional regulator of a group of genes that are essential for aromatic amino acid biosynthesis and transport. the tyrr protein can function either as a repressor or as an activator. the central region of the tyrr protein (residues 207 to 425) is similar to corresponding polypeptide segments of the ntrc protein superfamily. like the ntrc protein, tyrr has intrinsic atpase activity. here, we report that tyrr possess ...	2000	10648532
fragmentation of 23s rrna in strains of proteus and providencia results from intervening sequences in the rrn (rrna) genes.	intervening sequences (ivss) were originally identified in the rrl genes for 23s rrna (rrl genes, for large ribosomal subunit, part of rrn operon encoding rrna) of salmonella enterica serovars typhimurium lt2 and arizonae. these sequences are transcribed but later removed during rnase iii processing of the rrna, resulting in fragmentation of the 23s species; ivss are uncommon, but have been reported in at least 10 bacterial genera. through pcr amplification of ivs-containing regions of the rrl g ...	2000	10648538
association of qace and qacedelta1 with multiple resistance to antibiotics and antiseptics in clinical isolates of gram-negative bacteria.	clinical isolates of enterobacter cloacae, citrobacter freundii, pseudomonas aeruginosa, and stenotrophomonas maltophilia were tested for resistance to antibiotics and to the antiseptics benzalkonium chloride and cetyltrimethylammonium bromide. furthermore, they were examined for the presence of the resistance genes qace and qacedelta1. qacedelta1 was detected by pcr in 10% of all (n=103) and in 81% of multiply antibiotic-resistant strains (n=15). qace was found in only one of 37 p. aeruginosa s ...	2000	10650208
selective and sensitive method for pcr amplification of escherichia coli 16s rrna genes in soil.	a set of pcr primers targeting 16s rrna gene sequences was designed, and pcr parameters were optimized to develop a robust and reliable protocol for selective amplification of escherichia coli 16s rrna genes. the method was capable of discriminating e. coli from other enteric bacteria, including its closest relative, shigella. selective amplification of e. coli occurred only when the annealing temperature in the pcr was elevated to 72 degrees c, which is 10 degrees c higher than the optimum for ...	2000	10653763
determination of escherichia coli contamination with chromocult coliform agar showed a high level of discrimination efficiency for differing fecal pollution levels in tropical waters of kampala, uganda.	escherichia coli, total coliforms, fecal coliforms, and sulfite-reducing anaerobic spore formers from different polluted sites in a tropical environment were determined in order to test for their indication ability for fecal contamination. quantification of e. coli contamination with chromocult coliform agar proved to be efficient and feasible for determining fecal pollutions in the investigated area within 24 h. the other microbial parameters showed a lower ability to differentiate sites and ca ...	2000	10653767
ability of the vitek 2 advanced expert system to identify beta-lactam phenotypes in isolates of enterobacteriaceae and pseudomonas aeruginosa.	the advanced expert system (aes) was used in conjunction with the vitek 2 automated antimicrobial susceptibility test system to ascertain the beta-lactam phenotypes of 196 isolates of the family enterobacteriaceae and the species pseudomonas aeruginosa. these isolates represented a panel of strains that had been collected from laboratories worldwide and whose beta-lactam phenotypes had been characterized by biochemical and molecular techniques. the antimicrobial susceptibility of each isolate wa ...	2000	10655347
problems related to determination of mics of oximino-type expanded-spectrum cephems for proteus vulgaris.	during in vitro susceptibility testing of clinical isolates of proteus vulgaris, we noted that the mics of several expanded-spectrum cephems were much higher in the broth microdilution method than in the agar dilution method (termed the mic gap phenomenon). here we investigated the mechanism of the mic gap phenomenon. cephems with the mic gap phenomenon were of the oximino type, such as cefotaxime, cefteram, and cefpodoxime, which serve as good substrates for inducible class a beta-lactamase (cu ...	2000	10655366
rapid diagnosis of bacteremia by universal amplification of 23s ribosomal dna followed by hybridization to an oligonucleotide array.	the rapid identification of bacteria in blood cultures and other clinical specimens is important for patient management and antimicrobial therapy. we describe a rapid (<4 h) detection and identification system that uses universal pcr primers to amplify a variable region of bacterial 23s ribosomal dna, followed by reverse hybridization of the products to a panel of oligonucleotides. this procedure was successful in discriminating a range of bacteria in pure cultures. when this procedure was appli ...	2000	10655385
fluorescent in situ hybridization allows rapid identification of microorganisms in blood cultures.	using fluorescent in situ hybridization (fish) with rrna-targeted fluorescently labelled oligonucleotide probes, pathogens were rapidly detected and identified in positive blood culture bottles without cultivation and biotyping. in this study, 115 blood cultures with a positive growth index as determined by a continuous-reading automated blood culture system were examined by both conventional laboratory methods and fish. for this purpose, oligonucleotide probes that allowed identification of app ...	2000	10655393
specificity of a conductance assay for enumeration of escherichia coli from broiler carcass rinse samples containing genetically similar species.	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 c ...	2000	10678434
in vitro activities of novel trans-3,5-disubstituted pyrrolidinylthio-1beta-methylcarbapenems with potent activities against methicillin-resistant staphylococcus aureus and pseudomonas aeruginosa.	the in vitro activities of the novel 1beta-methylcarbapenems j-111, 225, j-114,870, and j-114,871, which have a structurally unique side chain that consists of a trans-3,5-disubstituted 5-arylpyrrolidin-3-ylthio moiety at the c-2 position, were compared with those of reference antibiotics. among isolates of both methicillin-resistant staphylococcus aureus (mrsa) and methicillin-resistant coagulase-negative staphylococci (mrcons), 90% were inhibited by j-111,347 (prototype), j-111,225, j-114,870, ...	2000	10681308
ampr gene mutations that greatly increase class c beta-lactamase activity in enterobacter cloacae.	the ampc and ampr genes of enterobacter cloacae gn7471 were cloned into pmw218 to yield pku403. four mutant plasmids derived from pku403 (pku404, pku405, pku406, and pku407) were isolated in an ampd mutant of escherichia coli ml4953 by selection with ceftazidime or aztreonam. the beta-lactamase activities expressed by pku404, pku405, pku406, and pku407 were about 450, 75, 160, and 160 times higher, respectively, than that expressed by the original plasmid, pku403. these mutant plasmids all carri ...	2000	10681318
inactivation of the ampd gene in pseudomonas aeruginosa leads to moderate-basal-level and hyperinducible ampc beta-lactamase expression.	it has been shown in enterobacteria that mutations in ampd provoke hyperproduction of chromosomal beta-lactamase, which confers to these organisms high levels of resistance to beta-lactam antibiotics. in this study, we investigated whether this genetic locus was implicated in the altered ampc beta-lactamase expression of selected clinical isolates and laboratory mutants of pseudomonas aeruginosa. the sequences of the ampd genes and promoter regions from these strains were determined and compared ...	2000	10681322
adult citrobacter freundii meningitis: case report.	citrobacter is a distinct group of gram-negative bacilli belonging to the enterobacteriaceae family. central nervous system (cns) infections due to citrobacter are uncommon, though they occur more frequently in neonates and young children. in adults, citrobacter meningitis is extremely unusual with only 6 cases reported in the literature before 1998. this rare cns infection has been seen in patients with head trauma, following neurosurgical procedures, and in those who are immunocompromised. of ...	1999	10695216
[the resistance of recent clinical isolates against isepamycin, other aminoglycosides and injectable beta-lactams].	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 amino ...	2000	10709145
pyridoxal 5'-phoshate schiff base in citrobacter freundii tyrosinephenol-lyase. ionic and tautomeric equilibria.	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 ...	2000	10712616
efficacies of imipenem, meropenem, cefepime, and ceftazidime in rats with experimental pneumonia due to a carbapenem-hydrolyzing beta-lactamase-producing strain of enterobacter cloacae.	the antibacterial activities of imipenem-cilastatin, meropenem-cilastatin, cefepime and ceftazidime against enterobacter cloacae nor-1, which produces the carbapenem-hydrolyzing beta-lactamase nmca and a cephalosporinase, and against one of its in vitro-obtained ceftazidime-resistant mutant were compared by using an experimental model of pneumonia with immunocompetent rats. the mics of the beta-lactams with an inoculum of 5 log(10) cfu/ml were as follows for e. cloacae nor-1 and its ceftazidime- ...	2000	10722486
a canadian national surveillance study of urinary tract isolates from outpatients: comparison of the activities of trimethoprim-sulfamethoxazole, ampicillin, mecillinam, nitrofurantoin, and ciprofloxacin. the canadian urinary isolate study group.	ampicillin, trimethoprim-sulfamethoxazole, mecillinam, nitrofurantoin, and ciprofloxacin mean resistance rates for 2,000 urinary tract isolates collected from outpatients across canada in 1998 were 41.1, 19.2, 14.7, 5.0, and 1.8%, respectively. for escherichia coli isolates alone (n = 1,681) comparable rates were 41. 0, 18.9, 7.4, 0.1, and 1.2%, respectively. the majority of e. coli isolates resistant to ampicillin, trimethoprim-sulfamethoxazole, or ciprofloxacin were susceptible (mic, <16 micro ...	2000	10722520
in vitro activities of sitafloxacin (du-6859a) and six other fluoroquinolones against 8,796 clinical bacterial isolates.	the in vitro activities of sitafloxacin, ciprofloxacin, trovafloxacin, levofloxacin, clinafloxacin, gatifloxacin, and moxifloxacin against 5,046 gram-negative bacteria, 3,344 gram-positive cocci, and 406 anaerobes were determined. sitafloxacin was the most active agent against gram-positive cocci and anaerobes. against enterobacteriaceae and nonfermenters, its activity was either equivalent to or better than that of clinafloxacin.	2000	10722524
a large toxin from pathogenic escherichia coli strains that inhibits lymphocyte activation.	the mechanisms by which bacteria resist cell-mediated immune responses to cause chronic infections are largely unknown. we report the identification of a large gene present in enteropathogenic strains of escherichia coli (epec) that encodes a toxin that specifically inhibits lymphocyte proliferation and interleukin-2 (il-2), il-4, and gamma interferon production in response to a variety of stimuli. lymphostatin, the product of this gene, is predicted to be 366 kda and shares significant homology ...	2000	10722613
role of tir and intimin in the virulence of rabbit enteropathogenic escherichia coli serotype o103:h2.	attaching and effacing (a/e) rabbit enteropathogenic escherichia coli (repec) strains belonging to serogroup o103 are an important cause of diarrhea in weaned rabbits. like human epec strains, they possess the locus of enterocyte effacement clustering the genes involved in the formation of the a/e lesions. in addition, pathogenic repec o103 strains produce an esp-dependent but eae (intimin)-independent alteration of the host cell cytoskeleton characterized by the formation of focal adhesion comp ...	2000	10722617
a two-component multidrug efflux pump, ebrab, in bacillus subtilis.	genes (ebrab) responsible for ethidium resistance were cloned from chromosomal dna of bacillus subtilis atcc 9372. the recombinant plasmid produced elevated resistance against ethidium bromide, acriflavine, pyronine y, and safranin o not only in escherichia coli but also in b. subtilis. it also caused an elevated energy-dependent efflux of ethidium in e. coli. ebra and ebrb showed high sequence similarity with members of the small multidrug resistance (smr) family of multidrug efflux pumps. neit ...	2000	10735876
the prevalence of gentamicin resistance among clinical isolates of enterobacteria in a danish region.	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 isolat ...	2000	10737460
evaluation of the wider system, a new computer-assisted image-processing device for bacterial identification and susceptibility testing.	the wider system is a newly developed computer-assisted image-processing device for both bacterial identification and antimicrobial susceptibility testing. it has been adapted to be able to read and interpret commercial microscan panels. two hundred forty-four fresh consecutive clinical isolates (138 isolates of the family enterobacteriaceae, 25 nonfermentative gram-negative rods [nfgnrs], and 81 gram-positive cocci) were tested. in addition, 100 enterobacterial strains with known beta-lactam re ...	2000	10747104
evaluation of the sirscan automated zone reader in a clinical microbiology laboratory.	we compared readings of kirby-bauer plates by the sirscan, an automated image analyzer that measures zone diameters, to those of experienced clinical microbiologists measuring zones with a hand-held caliper interfaced to a computer and with a ruler. to read plates of escherichia coli, morganella morganii, and pseudomonas aeruginosa containing 12 antibiotic disks the sirscan took 11 s; technologists took 28 s by caliper and 39 s by ruler. reading times of four different technologists ranged from ...	2000	10747172
in vitro selected fluoroquinolone-resistant mutants of citrobacter freundii: analysis of the quinolone resistance acquisition.	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 associ ...	2000	10747831
analysis of the mechanisms of quinolone resistance in clinical isolates of citrobacter freundii		2000	10747842
an immunoglobulin superfamily-like domain unique to the yersinia pseudotuberculosis invasin protein is required for stimulation of bacterial uptake via integrin receptors.	the binding of the yersinia pseudotuberculosis and yersinia enterocolitica invasin proteins to beta(1) integrin receptors allows internalization of these organisms by cultured cells. the c-terminal 192-residue superdomain of the y. pseudotuberculosis invasin is necessary and sufficient for integrin recognition, while a region located outside, and n-terminal to, this superdomain strongly enhances the efficiency of bacterial uptake. within the enhancer region is a domain called d2 that allows inva ...	2000	10768991
citrobacter freundii tyrosine phenol-lyase: the role of asparagine 185 in modulating enzyme function through stabilization of a quinonoid intermediate.	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 substitutio ...	2000	10775663
ascending cholangitis as a cause of pyogenic liver abscesses complicated by a gastric submucosal abscess and fistula.	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 ca ...	2000	10777197
[detection of extended spectrum beta-lactamases producing enterobacteriaceae in feces].	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 cefotaxim ...	2000	10783580
production and characterization of monoclonal antibodies against vegetative cells of bacillus cereus.	two monoclonal antibodies (mabs) against bacillus cereus were produced. the mabs (8d3 and 9b7) were selected by enzyme-linked immunosorbent assay for their reactivity with b. cereus vegetative cells. they reacted with b. cereus vegetative cells while failing to recognize b. cereus spores. immunoblotting revealed that mab 8d3 recognized a 22-kda antigen, while mab 9b7 recognized two antigens with molecular masses of approximately 58 and 62 kda. the use of mabs 8d3 and 9b7 in combination to develo ...	2000	10788418
a pcr-colorimetric microwell plate hybridization assay for detection of mycobacterium tuberculosis and m. avium from culture samples and ziehl-neelsen-positive smears.	differentiation between mycobacterium tuberculosis and m. avium is essential for the treatment of mycobacterial infections. we have developed an easy and rapid detection assay for the diagnosis of mycobacterial diseases. this is a pcr-hybridization assay based on selective amplification of a 16s rrna gene sequence using pan-mycobacterium primers followed by hybridization of the amplification products to biotinylated m. tuberculosis and m. avium-specific probes. a total of 55 mycobacterial isolat ...	2000	10790097
occurrence and detection of ampc beta-lactamases among escherichia coli, klebsiella pneumoniae, and proteus mirabilis isolates at a veterans medical center.	ampc beta-lactamases are cephalosporinases that confer resistance to a wide variety of beta-lactam drugs and that may thereby create serious therapeutic problems. although reported with increasing frequency, the true rate of occurrence of ampc beta-lactamases in escherichia coli, klebsiella pneumoniae, and proteus mirabilis remains unknown. we tested a total of 1,286 consecutive, nonrepeat isolates of these three species and found that, overall, 45 (3.5%) yielded a cefoxitin zone diameter less t ...	2000	10790101
direct molecular typing of borrelia burgdorferi sensu lato species in synovial samples from patients with lyme arthritis.	since lyme arthritis was first described in the united states, it has now been reported in many countries of europe. however, very few strains of the causative bacterium, borrelia burgdorferi, have been isolated from synovial samples. for this reason, different molecular direct typing methods were developed recently to assess which species could be involved in lyme arthritis in europe. we developed a simple oligonucleotide typing method with pcr fragments from the flagellin gene of b. burgdorfer ...	2000	10790118
isolation of yersinia enterocolitica from cases of acute appendicitis and ice-cream.	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 ...	1999	10793790
structure and serologic properties of o-specific polysaccharide from citrobacter freundii possessing cross-reactivity with escherichia coli o157:h7.	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: [--> ...	2000	10799808
molecular beacons: a real-time polymerase chain reaction assay for detecting salmonella.	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 beaco ...	2000	10805535
interaction of listeria monocytogenes with human brain microvascular endothelial cells: an electron microscopic study.	internalization of listeria monocytogenes into human brain microvascular endothelial cells (hbmec) has recently been demonstrated to be dependent upon the inlb gene. in the present scanning electron microscopic study we show that l. monocytogenes efficiently interacts with the surface of hbmec in an inlb-independent manner which is also different from invasion. the inlb-dependent invasion of hbmec by l. monocytogenes is accompanied by intracellular multiplication, movement, and production of bac ...	2000	10816473
carbapenemases of chryseobacterium (flavobacterium) meningosepticum: distribution of blab and characterization of a novel metallo-beta-lactamase gene, blab3, in the type strain, nctc 10016.	genes encoding carbapenemases in 15 reference strains of chryseobacterium (flavobacterium) meningosepticum from the united kingdom national collection of type cultures and in one recent clinical isolate were investigated. all the strains hydrolyzed imipenem, but their levels of resistance to carbapenems varied, with imipenem and meropenem mics ranging from 2 to >32 microg/ml. the blab gene, which encodes a molecular-class b carbapenemase, was detected in only six reference strains and in clinica ...	2000	10817691
biochemical-genetic characterization and regulation of expression of an acc-1-like chromosome-borne cephalosporinase from hafnia alvei.	a naturally occurring ampc beta-lactamase (cephalosporinase) gene was cloned from the hafnia alvei 1 clinical isolate and expressed in escherichia coli. the deduced ampc beta-lactamase (acc-2) had a pi of 8 and a relative molecular mass of 37 kda and showed 50 and 47% amino acid identity with the chromosome-encoded ampcs from serratia marcescens and providentia stuartii, respectively. it had 94% amino acid identity with the recently described plasmid-borne cephalosporinase acc-1 from klebsiella ...	2000	10817695
a between-species comparison of antimicrobial resistance in enterobacteria in fecal flora.	enterobacteria in fecal flora are often reported to be highly resistant. escherichia coli is the main species; resistance data on other species are rare. to assess the effect of the host's environment, antimicrobial resistance was determined in fecal species of the family enterobacteriaceae from three populations: healthy people (hp)(n = 125) with no exposure to antimicrobials for 3 months preceding sampling, university hospital patients (up) (n = 159) from wards where the antibiotic use was 112 ...	2000	10817696
activities of taurolidine in vitro and in experimental enterococcal endocarditis.	in vitro, the antimicrobial agent taurolidine inhibited virtually all of the bacteria tested, including vancomycin-resistant enterococci, oxacillin-resistant staphylococci, and stenotrophomonas maltophilia, at concentrations between 250 and 2,000 microg/ml. taurolidine was not effective in experimental endocarditis. while it appears unlikely that this antimicrobial would be useful for systemic therapy, its bactericidal activity and the resistance rates found (<10(-9)) are favorable indicators fo ...	2000	10817739
in vitro activity of gemifloxacin against a broad range of recent clinical isolates from the usa.	the antibacterial potencies of gemifloxacin (sb-265805) and 13 comparator compounds were determined by broth microdilution against a panel of 645 gram-positive and 995 gram-negative organisms collected from various usa sites. time-kill studies were performed and postantibiotic effect (pae) was determined for several organisms using trovafloxacin and ciprofloxacin as comparator compounds. based on mic(90)s, gemifloxacin was the most potent compound tested against gram-positive isolates: streptoco ...	2000	10824027
prevalence of salmonella spp. in poultry broilers and shell eggs in korea.	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 ...	2000	10826725
the macrocyclic peptide antibiotic micrococcin p(1) is secreted by the food-borne bacterium staphylococcus equorum ws 2733 and inhibits listeria monocytogenes on soft cheese.	staphylococcus equorum ws 2733 was found to produce a substance exhibiting a bacteriostatic effect on a variety of gram-positive bacteria. the metabolite was purified to homogeneity by ammonium sulfate precipitation and semipreparative reversed-phase high-performance liquid chromatography. electrospray mass spectrometry confirmed the high purity of the compound and revealed a molecular mass of 1,143 da. by two-dimensional nuclear magnetic resonance spectroscopy the substance was identified as mi ...	2000	10831414
molecular characteristics and epidemiological significance of shiga toxin-producing escherichia coli o26 strains.	fifty-five shiga toxin (stx)-producing escherichia coli (stec) o26:h11 and o26:h(-) strains isolated from humans between 1965 and 1999 in germany and the czech republic were investigated for their chromosomal and plasmid characteristics. all motile (n = 23) and nonmotile (n = 32) stec o26 strains were shown to possess the identical flagellin subunit-encoding gene (flic). we observed a striking recent shift of the stx genotype from stx(1) to stx(2) among the stec o26 isolates. while stx(1) was th ...	2000	10834966
enteropathogenic escherichia coli isolates in paediatric diarrhoea.	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 ...	2000	10835962
type i restriction systems: sophisticated molecular machines (a legacy of bertani and weigle).	restriction enzymes are well known as reagents widely used by molecular biologists for genetic manipulation and analysis, but these reagents represent only one class (type ii) of a wider range of enzymes that recognize specific nucleotide sequences in dna molecules and detect the provenance of the dna on the basis of specific modifications to their target sequence. type i restriction and modification (r-m) systems are complex; a single multifunctional enzyme can respond to the modification state ...	2000	10839821
prevalence of virulence genes and clonality in escherichia coli strains that cause bacteremia in cancer patients.	phenotypic analysis of escherichia coli strains causing bacteremia in cancer patients suggests that they possess specific virulence properties. to investigate this hypothesis, we compared the frequency of the virulence-related genes cnf1, cnf2, papc, hlyc, and iut in 155 e. coli strains isolated from hospitalized cancer patients with epidemiologically unrelated cases of bacteremia to their frequency in 70 e. coli strains isolated from the feces of healthy unrelated volunteers. of the blood isola ...	2000	10858212
a novel ctx-m beta-lactamase (ctx-m-8) in cefotaxime-resistant enterobacteriaceae isolated in brazil.	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. ...	2000	10858358
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.	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.	2000	10859431
modification of the bile salts-irgasan-brilliant green agar for enumeration of aeromonas species from food.	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 pseudomon ...	2000	10868682
assessment of the microbiological quality and wash treatments of lettuce served in university restaurants.	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 ...	2000	10898470
involvement of a plasmid in virulence of campylobacter jejuni 81-176.	campylobacter jejuni strain 81-176 contains two, previously undescribed plasmids, each of which is approximately 35 kb in size. although one of the plasmids, termed ptet, carries a teto gene, conjugative transfer of tetracycline resistance to another strain of c. jejuni could not be demonstrated. partial sequence analysis of the second plasmid, pvir, revealed the presence of four open reading frames which encode proteins with significant sequence similarity to helicobacter pylori proteins, inclu ...	2000	10899834
cloning and dna sequence analysis of an immunogenic glucose-galactose mglb lipoprotein homologue from brachyspira pilosicoli, the agent of colonic spirochetosis.	colonic spirochetosis (cs) is a newly emerging infectious disease of humans and animals caused by the pathogenic spirochete brachyspira (formerly serpulina) pilosicoli. the purpose of this study was to characterize an antigen that was recognized by antibodies present in sera of challenge-exposed pigs. the gene encoding the antigen was identified by screening a plasmid library of human b. pilosicoli strain sp16 (atcc 49776) genomic dna with hyperimmune and convalescent swine sera. the predicted a ...	2000	10899855
expression of intimin gamma from enterohemorrhagic escherichia coli in citrobacter rodentium.	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 ...	2000	10899867
constitutive expression of the vi polysaccharide capsular antigen in attenuated salmonella enterica serovar typhi oral vaccine strain cvd 909.	live oral ty21a and parenteral vi polysaccharide vaccines provide significant protection against typhoid fever, albeit by distinct immune mechanisms. vi stimulates serum immunoglobulin g vi antibodies, whereas ty21a, which does not express vi, elicits humoral and cell-mediated immune responses other than vi antibodies. protection may be enhanced if serum vi antibody as well as cell-mediated and humoral responses can be stimulated. disappointingly, several new attenuated salmonella enterica serov ...	2000	10899868
the role of glutamic acid-69 in the activation of citrobacter freundii tyrosine phenol-lyase by monovalent cations.	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. ...	2000	10913261
a genomic sample sequence of the entomopathogenic bacterium photorhabdus luminescens w14: potential implications for virulence.	photorhabdus luminescens is a pathogenic bacterium that lives in the guts of insect-pathogenic nematodes. after invasion of an insect host by a nematode, bacteria are released from the nematode gut and help kill the insect, in which both the bacteria and the nematodes subsequently replicate. however, the bacterial virulence factors associated with this "symbiosis of pathogens" remain largely obscure. in order to identify genes encoding potential virulence factors, we performed approximately 2,00 ...	2000	10919786
detection of significant bacteriuria by automated urinalysis using flow cytometry.	a new flow cytometry-based automated urine analyzer, the uf-50, was evaluated for its ability to screen urine samples for significant bacteriuria. one hundred eighty-six urine specimens from patients attending an outpatient clinic of a university-based hospital were examined. the results obtained with the uf-50 were compared with those obtained by conventional quantitative urine culture. the uf-50 detected significant bacteriuria with a sensitivity of 83.1%, a specificity of 76.4%, a positive pr ...	2000	10921941
exploitation of host cells by enteropathogenic escherichia coli.	microbial pathogens have evolved many ingenious ways to infect their hosts and cause disease, including the subversion and exploitation of target host cells. one such subversive microbe is enteropathogenic escherichia coli (epec). a major cause of infantile diarrhea in developing countries, epec poses a significant health threat to children worldwide. central to epec-mediated disease is its colonization of the intestinal epithelium. after initial adherence, epec causes the localized effacement o ...	2000	10922038
prediction of two- and three-amino-acid sequences of citrobacter freundii beta-lactamase from its amino acid composition.	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 ...	2000	10937436
purification and characterization of the 1-3-propanediol dehydrogenase of clostridium butyricum e5.	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 preferre ...	2000	10938419
inactivation of the ampde operon increases transcription of algd and affects morphology and encystment of azotobacter vinelandii.	transcription of algd, encoding gdp-mannose dehydrogenase, the key enzyme in the alginate biosynthetic pathway, is highly regulated in azotobacter vinelandii. we describe here the characterization of a tn5 insertion mutant (ac28) which shows a higher level of expression of an algd::lacz fusion. ac28 cells were morphologically abnormal and unable to encyst. the cloning and nucleotide sequencing of the tn5-disrupted locus in ac28 revealed an operon homologous to the escherichia coli ampde operon. ...	2000	10940024
bacterial quorum sensing in pathogenic relationships.		2000	10948095
characterization of porphyromonas gingivalis insertion sequence-like element ispg5.	porphyromonas gingivalis, a black-pigmented, gram-negative anaerobe, is found in periodontitis lesions, and its presence in subgingival plaque significantly increases the risk for periodontitis. in contrast to many bacterial pathogens, p. gingivalis strains display considerable variability, which is likely due to genetic exchange and intragenomic changes. to explore the latter possibility, we have studied the occurrence of insertion sequence (is)-like elements in p. gingivalis w83 by utilizing a ...	2000	10948151
neisseria gonorrhoeae elicits membrane ruffling and cytoskeletal rearrangements upon infection of primary human endocervical and ectocervical cells.	neisseria gonorrhoeae is a strict human pathogen that is, primarily, transmitted by close sexual contact with an infected individual. gonococcal infection of the male urogenital tract has been well studied in experimental human models and in urethral cell culture systems. recent studies, using tissue culture cell systems, have suggested a role for the cervical epithelium in gonococcal infection of females; however, the nature of gonococcal infection of the normal uterine cervix remains controver ...	2000	10948165
efflux-mediated resistance to fluoroquinolones in gram-negative bacteria.		2000	10952561
functional analysis of the active site of a metallo-beta-lactamase proliferating in japan.	an r-plasmid-mediated metallo-beta-lactamase was found in klebsiella pneumoniae dk4 isolated in japan in 1991. the nucleotide sequence of its structural gene revealed that the beta-lactamase termed dk4 was identical to the imp-1 metallo-beta-lactamase which was mediated by a chromosomal gene of serratia marcescens tn9106 isolated in japan in 1991 (e. osano et al., antimicrob. agents chemother. 38:71-78, 1994). the dose effect of dk4 beta-lactamase production on the resistance levels indicated a ...	2000	10952572
ofloxacin-loaded liposomes: in vitro activity and drug accumulation in bacteria.	different ofloxacin-loaded unilamellar vesicles were prepared by the extrusion technique, and their antimicrobial activities were determined in comparison to those of the free drug by means of mic determinations with both american type culture collection standards and wild-type bacterial strains (six strains of enterococcus faecalis, seven strains of escherichia coli, six strains of staphylococcus aureus, and six strains of pseudomonas aeruginosa). the accumulation of ofloxacin and liposome-oflo ...	2000	10952595
molecular characterization of fox-4, a new ampc-type plasmid-mediated beta-lactamase from an escherichia coli strain isolated in spain.	a clinical strain of escherichia coli (ec gce) displayed resistance to cefoxitin, cefotetan, cefotaxime, and ceftazidime. susceptibility was not restored by the addition of clavulanic acid. two beta-lactamases with apparent pis of 5.4 and 6.4 were identified; the beta-lactamase with a pi of 6.4 was transferred by conjugation and associated with a 40-kb plasmid. analysis of the nucleotide sequence showed a new ampc beta-lactamase gene that is closely related to those encoding the fox-3, fox-2, an ...	2000	10952615
application of the 5'-nuclease pcr assay in evaluation and development of methods for quantitative detection of campylobacter jejuni.	campylobacter jejuni is recognized as a leading human food-borne pathogen. traditional diagnostic testing for c. jejuni is not reliable due to special growth requirements and the possibility that this bacterium can enter a viable but nonculturable state. nucleic acid-based tests have emerged as a useful alternative to traditional enrichment testing. in this article, we present a 5'-nuclease pcr assay for quantitative detection of c. jejuni and describe its evaluation. a probe including positions ...	2000	10966425