Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| safety and immune responses to attenuated salmonella enterica serovar typhi oral live vector vaccines expressing tetanus toxin fragment c. | attenuated salmonella enterica serovar typhi vaccine strain cvd 908-htra was used as a vector to deliver fragment c of tetanus toxin as a single-dose oral tetanus vaccine candidate to elicit protective levels of serum tetanus antitoxin. twenty-one healthy adult volunteers received doses of 1.6 x 10(7) to 8.2 x 10(9) cfu of one of two strains, cvd 908-htra(ptetnir15) or cvd 908-htra(ptetlpp), which contained plasmid-encoded fragment c, with sodium bicarbonate, and the safety and immune responses ... | 2000 | 11027455 |
| phage types of salmonella enterica serovar enteritidis isolated in south africa from 1991-1995. | a total of 615 strains of salmonella enterica serovar enteritidis (se), received from 1991-1995 at the onderstepoort veterinary institute (ovi), were phage typed. most se isolates (54,7%) originated from poultry followed by humans (28,5 %) and poultry eggs (9,6 %). phage type 34 was the most prevalent (40,5 %) of all isolates, followed by phage type 4 (33,8 %). other phage types identified were 1, lb, 4a, 7, 7a, 9a, 14, 24, 24var and 35 (in total 2,4% of isolates). most isolates of se were recei ... | 2000 | 11028749 |
| acquisition of the rfb-gnd cluster in evolution of escherichia coli o55 and o157. | the rfb region specifies the structure of lipopolysaccharide side chains that comprise the diverse gram-negative bacterial somatic (o) antigens. the rfb locus is adjacent to gnd, which is a polymorphic gene encoding 6-phosphogluconate dehydrogenase. to determine if rfb and gnd cotransfer, we sequenced gnd in five o55 and 13 o157 strains of escherichia coli. e. coli o157:h7 has a gnd allele (allele a) that is only 82% identical to the gnd allele (allele d) of closely related e. coli o55:h7. in co ... | 2000 | 11029441 |
| molecular characterisation of emergent multiresistant salmonella enterica serotype [4,5,12:i:-] organisms causing human salmonellosis. | salmonella multidrug-resistant clinical organisms identified as serotype [4,5,12:i:-] were typed using selected genetic procedures and compared with typhimurium organisms collected in the same spanish region. results showed a low genetic heterogeneity among [4,5,12:i:-] organisms, which generated identical ribotypes and similar but not identical xbai pfge, rapd, and plasmid profiles. multidrug resistance could be eliminated by curing and seems to be mediated by 140-kb (spvc+) and 120-kb (spvc-) ... | 2000 | 11034302 |
| genetic and functional analysis of a pmra-pmrb-regulated locus necessary for lipopolysaccharide modification, antimicrobial peptide resistance, and oral virulence of salmonella enterica serovar typhimurium. | the two-component regulatory system pmra-pmrb confers resistance of salmonella spp. to cationic antimicrobial peptides (ap) such as polymyxin (pm), bactericidal/permeability-increasing protein, and azurocidin. this resistance occurs by transcriptional activation of two loci termed pmre and pmrhfijklm. both pmre and pmrhfijklm produce products required for the biosynthesis of lipid a with 4-aminoarabinose (ara4n). ara4n addition creates a more positively charged lipopolysaccharide (lps) and thus ... | 2000 | 11035717 |
| salmonella enterica serovar typhimurium-induced maturation of bone marrow-derived dendritic cells. | murine bone marrow-derived dendritic cells (dc) can phagocytose and process salmonella enterica serovar typhimurium for peptide presentation on major histocompatibility complex class i (mhc-i) and mhc-ii molecules. to investigate if a serovar typhimurium encounter with dc induces maturation and downregulates their ability to present antigens from subsequently encountered bacteria, dc were pulsed with serovar typhimurium 24 h prior to coincubating with escherichia coli expressing the model antige ... | 2000 | 11035740 |
| a novel action of the proton pump inhibitor rabeprazole and its thioether derivative against the motility of helicobacter pylori. | the motility of helicobacter pylori was maximum at 37 degrees c and at ph 6. a newly developed proton pump inhibitor, rabeprazole (rpz), and its thioether derivative (rpz-th) markedly inhibited the motility of h. pylori. the concentrations of the drug necessary to inhibit 50% of the motility were 0.25, 16, 16, and >64 microgram/ml for rpz-th, rpz, lansoprazole, and omeprazole, respectively. no such inhibitory effects were observed with h(2) blockers or anti-h. pylori agents. the motilities of ca ... | 2000 | 11036024 |
| evidence for an efflux pump mediating multiple antibiotic resistance in salmonella enterica serovar typhimurium. | the mechanism of multiple antibiotic resistance in six isolates of salmonella enterica serovar typhimurium recovered from a patient treated with ciprofloxacin was studied to investigate the role of efflux in the resistance phenotype. compared to the patient's pretherapy isolate (l3), five of six isolates accumulated less ciprofloxacin, three of six isolates accumulated less chloramphenicol, and all six accumulated less tetracycline. the accumulation of one or more antibiotics was increased by ca ... | 2000 | 11036033 |
| biological cost of ampc production for salmonella enterica serotype typhimurium. | chromosomally mediated ampc-type beta-lactamases are frequently found among enterobacteriaceae. hyperproduction of ampc beta-lactamase results in high-level resistance to beta-lactam antibiotics. one striking feature of salmonella is the absence of the structural ampc gene, encoding ampc beta-lactamase, in contrast with other members in the enterobacteriaceae family, such as escherichia, citrobacter, or enterobacter. the horizontal acquisition of ampc genes is one of the causes of the increased ... | 2000 | 11036037 |
| competitive exclusion treatment reduces the mortality and fecal shedding associated with enterotoxigenic escherichia coli infection in nursery-raised neonatal pigs. | we have previously reported that the administration of a competitive exclusion culture (pcf-1), derived from the cecal microflora of a young, healthy pig and maintained in a continuous flow fermentation system to neonatal pigs resulted in a decrease in the incidence of fecal shedding and cecal colonization by salmonella choleraesuis in pigs at weaning. in the present experiment, we describe the effects of the administration of a derivative of the pcf-1 culture, rpcf, against an enterotoxigenic e ... | 2000 | 11041496 |
| [possibilities for standardization of elisa for detection of salmonella antibodies in sera and meat juices of pigs]. | programmes for controlling salmonella infections in german piggeries are based on the meat-juice-elisa conducted in various investigation centres by using different test-kits. a usual procedure for harmonization (standardisation) of results is the calculation of the percentage of antibody-concentration from field samples in relation to the extinctions of a set of control-sera with known antibody concentrations. whether this system is still acceptable in case of using different test-kits seems to ... | 2000 | 11042945 |
| a signal transduction system that responds to extracellular iron. | iron is essential for all organisms but can be toxic in excess. iron homeostasis is typically regulated by cytoplasmic iron binding proteins, but here we describe a signal transduction system (pmra/pmrb) that responds to extracytoplasmic ferric iron. iron promoted transcription of pmra-activated genes and resistance to the antibiotic polymyxin in salmonella. the pmrb protein bound iron via its periplasmic domain which harbors two copies of the sequence exxe, a motif present in the saccharomyces ... | 2000 | 11051552 |
| genetics of swarming motility in salmonella enterica serovar typhimurium: critical role for lipopolysaccharide. | salmonella enterica serovar typhimurium can differentiate into hyperflagellated swarmer cells on agar of an appropriate consistency (0.5 to 0.8%), allowing efficient colonization of the growth surface. flagella are essential for this form of motility. in order to identify genes involved in swarming, we carried out extensive transposon mutagenesis of serovar typhimurium, screening for those that had functional flagella yet were unable to swarm. a majority of these mutants were defective in lipopo ... | 2000 | 11053374 |
| sequence of the genome of salmonella bacteriophage p22. | the sequence of the nonredundant region of the salmonella enterica serovar typhimurium temperate, serotype-converting bacteriophage p22 has been completed. the genome is 41,724 bp with an overall moles percent gc content of 47.1%. numerous examples of potential integration host factor and c1-binding sites were identified in the sequence. in addition, five potential rho-independent terminators were discovered. sixty-five genes were identified and annotated. while many of these had been described ... | 2000 | 11053393 |
| transcription initiation-defective forms of sigma(54) that differ in ability to function with a heteroduplex dna template. | transcription by sigma(54)-rna polymerase holoenzyme requires an activator that catalyzes isomerization of the closed promoter complex to an open complex. we examined mutant forms of salmonella enterica serovar typhimurium sigma(54) that were defective in transcription initiation but retained core rna polymerase- and promoter-binding activities. four of the mutant proteins allowed activator-independent transcription from a heteroduplex dna template. one of these mutant proteins, l124p v148a, had ... | 2000 | 11053397 |
| molecular analysis of tetracycline resistance in salmonella enterica subsp. enterica serovars typhimurium, enteritidis, dublin, choleraesuis, hadar and saintpaul: construction and application of specific gene probes. | a total of 65 epidemiologically unrelated tetracycline-resistant isolates of the six salmonella enterica subsp. enterica (salm.) serovars dublin, choleraesuis, typhimurium, enteritidis, hadar and saintpaul were investigated for the presence of tetracycline resistance genes. for this, specific gene probes of the tetracycline resistance genes (tet) of the hybridization classes a, b, c, d, e and g were constructed by cloning pcr-amplified internal segments of the respective tet structural genes. th ... | 2000 | 11054167 |
| characterization and chromosomal mapping of antimicrobial resistance genes in salmonella enterica serotype typhimurium. | two hundred and twenty-six salmonella enterica serotype typhimurium isolates were examined for the presence of integron-associated gene cassettes. all but two of the non-dt104 isolates, together with dt104 isolates, contained gene cassettes. amplicons of 1.5 kbp each were found in two non-dt104 isolates, encoding a dhfri gene (trimethoprim resistance) linked to an aada gene (streptomycin and spectinomycin resistance), by site-specific recombination. dt104 isolates of resistance (r) type acssut p ... | 2000 | 11055933 |
| resistance to ceftriaxone and cefotaxime in non-typhoidal salmonella enterica in england and wales, 1998-99. | 2000 | 11062222 | |
| rapid detection of salmonella enterica serovar choleraesuis in blood cultures by a dot blot enzyme-linked immunosorbent assay. | a dot blot enzyme-linked immunosorbent assay (elisa) with a monoclonal antibody specific to phase1-c salmonella was developed for the direct detection of salmonella enterica serovar choleraesuis in blood cultures. this system was applied to the identification of serovar choleraesuis, and the results were compared with those obtained by a conventional biochemical method. it was revealed that all 12 samples identified to be infected with serovar choleraesuis were positive on testing by the elisa. ... | 2000 | 11063509 |
| application of randomly amplified polymorphic dna (rapd) analysis for typing avian salmonella enterica subsp. enterica. | randomly amplified polymorphic dna (rapd) analysis was performed for the molecular genetic typing of 30 salmonella enterica subsp. enterica strains isolated from chickens and ducks in thailand. six different primers were tested for their discriminatory ability. while some of the primers could only differentiate between the different serovars, the use of multiple primers showed that the rapd method could also subdivide within a given serovar. the ready-to-go rapd analysis beads used, resulted in ... | 2000 | 11064269 |
| purification and characterization of waap from escherichia coli, a lipopolysaccharide kinase essential for outer membrane stability. | in escherichia coli, salmonella enterica, and pseudomonas aeruginosa, the waap (rfap) gene product is required for the addition of phosphate to o-4 of the first heptose residue of the lipopolysaccharide (lps) inner core region. this phosphate substitution is particularly important to the biology of these bacteria; it has previously been shown that waap is necessary for resistance to hydrophobic and polycationic antimicrobials in e. coli and that it is required for virulence in invasive strains o ... | 2001 | 11069912 |
| invb is a type iii secretion chaperone specific for sspa. | a wide variety of gram-negative bacteria utilize a specialized apparatus called the type iii secretion system (ttss) to translocate virulence factors directly into the cytoplasm of eukaryotic cells. these translocated effectors contribute to the pathogen's ability to infect and replicate within plant and animal hosts. the amino terminus of effector proteins contains sequences that are necessary and sufficient for both secretion and translocation by ttss. portions of these sequences contain bindi ... | 2000 | 11073906 |
| genotypic analysis of multidrug-resistant salmonella enterica serovar typhi, kenya. | we report the emergence in kenya during 1997-1999 of typhoid fever due to salmonella enterica serovar typhi resistant to ampicillin, tetracycline, chloramphenicol, streptomycin, and cotrimoxazole. genotyping by pulsed-field gel electrophoresis of xbai-digested chromosomal dna yielded a single cluster. the multidrug-resistant s. typhi were related to earlier drug- susceptible isolates but were unrelated to multidrug-resistant isolates from asia. | 2000 | 11076726 |
| an outbreak of salmonella hadar associated with roast rabbit in a restaurant. | in august 1997, an outbreak of gastroenteritis from salmonella hadar phage type 2 occurred among customers of a restaurant in rimini (emilia-romagna region, italy). twenty-nine people who had eaten food prepared in the restaurant on 2 or 3 august had symptoms of acute gastroenteritis. the infection was culture-confirmed in 24 cases and the stool specimens of four healthy people were positive for salmonella hadar. twelve people had to be hospitalized and a 3-year old girl died. the case-control s ... | 2000 | 11078117 |
| salmonella enterica serovar typhimurium invasion is repressed in the presence of bile. | as enteric pathogens, the salmonellae have developed systems by which they can sense and adapt appropriately to deleterious intestinal components that include bile. previously, growth in the presence of bile was shown to repress the transcription of prgh, a locus encoding components of the salmonella pathogenicity island i (spi-1) type iii secretion system (ttss) necessary for eukaryotic cell invasion. this result suggested an existing interaction between salmonellae, bile, and eukaryotic cell i ... | 2000 | 11083793 |
| regulation of salmonella enterica serovar typhimurium invasion genes by csra. | penetration of intestinal epithelial cells by salmonella enterica serovar typhimurium requires the expression of invasion genes, found in salmonella pathogenicity island 1 (spi1), that encode components of a type iii secretion apparatus. these genes are controlled in a complex manner by regulators within spi1, including hila and invf, and those outside spi1, such as the two-component regulators phop/phoq and bara/sira. we report here that epithelial cell invasion requires the serovar typhimurium ... | 2000 | 11083797 |
| development of an in vivo model for study of intestinal invasion by salmonella enterica in chickens. | an in vivo loop test model for the investigation of the invasiveness of salmonella enterica in chickens was developed. ten jejunal loops were made in 10- to 12-week-old lohman brown chickens under isofluoran anaesthesia. salmonella at 5.0 x 10(7) cfu was inoculated into each loop and left for 2 h, followed by a 1-h incubation with gentamicin in order to kill noninvading bacteria. after euthanasia, salmonella invasiveness was measured as tissue-associated counts relative to a reference strain. th ... | 2000 | 11083838 |
| mig-14 is a horizontally acquired, host-induced gene required for salmonella enterica lethal infection in the murine model of typhoid fever. | we have characterized a host-induced virulence gene, mig-14, that is required for fatal infection in the mouse model of enteric fever. mig-14 is present in all salmonella enterica subspecies i serovars and maps to a region of the chromosome that appears to have been acquired by horizontal transmission. a mig-14 mutant replicated in host tissues early after infection but was later cleared from the spleens and livers of infected animals. bacterial clearance by the host occurred concomitantly with ... | 2000 | 11083839 |
| localization of dysfunctional tight junctions in salmonella enterica serovar typhimurium-infected epithelial layers. | infection of polarized mdck epithelial layers by salmonella enterica serovar typhimurium is accompanied by increased tight junction permeability and by contraction of perijunctional actinomyosin. we localized dysfunctional tight junctions in serovar typhimurium-infected mdck layers by imaging apical-basolateral intramembrane diffusion of fluorescent lipid and found that loss of the apical-basolateral diffusion barrier (tight junction fence function) was most marked in areas of prominent perijunc ... | 2000 | 11083857 |
| role of molecular typing in an outbreak of salmonella paratyphi a. | during the post monsoon season of 1996 an outbreak of human salmonellosis caused by salmonella serovar-paratyphi a occurred in new delhi and had continued for over 2 months. a total of 36 clinically diagnosed enteric-fever cases were reported during this outbreak. the isolates were compared following their characterisation by biotyping, antibiogram-analysis, plasmid-profiling and is200 probing, to study the relatedness in order to delineate a common source. the study included representative stra ... | 2000 | 11084832 |
| natural antibiotic susceptibility of salmonella enterica strains. | the susceptibility of 100 salmonella enterica strains belonging to s. enterica subsp. enterica (n=90) and s. enterica subsp. arizonae (n=10) was examined to 71 antibiotics. within s. enterica subsp. enterica, strains of different serovars (typhimurium (n=17), enteritidis (n=17), dublin (n=10), typhi (n=16), paratyphi a (n=6), others (n=24)) were studied. mics were determined using a microdilution procedure and apart from fosfomycin there were no significant differences in susceptibility between ... | 2000 | 11091038 |
| pcr detection of salmonella enterica serotype montevideo in and on raw tomatoes using primers derived from hila. | salmonellae have been some of the most frequently reported etiological agents in fresh-produce-associated outbreaks of human infections in recent years. pcr assays using four innovative pairs of primers derived from hila and sira, positive regulators of salmonella invasive genes, were developed to identify salmonella enterica serotype montevideo on and in tomatoes. based on examination of 83 salmonella strains and 22 non-salmonella strains, we concluded that a pair of hila primers detects salmon ... | 2000 | 11097898 |
| application of a propionyl coenzyme a synthetase for poly(3-hydroxypropionate-co-3-hydroxybutyrate) accumulation in recombinant escherichia coli. | the genetic operon for propionic acid degradation in salmonella enterica serovar typhimurium contains an open reading frame designated prpe which encodes a propionyl coenzyme a (propionyl-coa) synthetase (a. r. horswill and j. c. escalante-semerena, microbiology 145:1381-1388, 1999). in this paper we report the cloning of prpe by pcr, its overexpression in escherichia coli, and the substrate specificity of the enzyme. when propionate was utilized as the substrate for prpe, a k(m) of 50 microm an ... | 2000 | 11097899 |
| suitability of pcr fingerprinting, infrequent-restriction-site pcr, and pulsed-field gel electrophoresis, combined with computerized gel analysis, in library typing of salmonella enterica serovar enteritidis. | strains of salmonella enterica (n = 212) of different serovars and phage types were used to establish a library typing computerized system for serovar enteritidis on the basis of pcr fingerprinting, infrequent-restriction-site pcr (irs-pcr), or pulsed-field gel electrophoresis (pfge). the rate of pcr fingerprinting interassay and intercenter reproducibility was low and was only increased when dna samples were extracted at the same time and amplified with the same reaction mixtures. reproducibili ... | 2000 | 11097902 |
| long-term shifts in patterns of antibiotic resistance in enteric bacteria. | several mechanisms are responsible for the ability of microorganisms to tolerate antibiotics, and the incidence of resistance to these compounds within bacterial species has increased since the commercial use of antibiotics became widespread. to establish the extent of and changes in the diversity of antibiotic resistance patterns in natural populations, we determined the mics of five antibiotics for collections of enteric bacteria isolated from diverse hosts and geographic locations and during ... | 2000 | 11097921 |
| simultaneous detection of salmonella strains and escherichia coli o157:h7 with fluorogenic pcr and single-enrichment-broth culture. | a multiplex fluorogenic pcr assay for simultaneous detection of pathogenic salmonella strains and escherichia coli o157:h7 was developed and evaluated for use in detecting very low levels of these pathogens in meat and feces. two sets of primers were used to amplify a junctional segment of virulence genes sipb and sipc of salmonella and an intragenic segment of gene eae of e. coli o157:h7. fluorogenic reporter probes were included in the pcr assay for automated and specific detection of amplifie ... | 2000 | 11097930 |
| [systems of epidemiological typing of microorganisms responsible for hospital infections: use and evaluation]. | 2000 | 11100554 | |
| evaluation of three newly developed enzyme-linked immunosorbent assays and two agglutination tests for detecting salmonella enterica subsp. enterica serovar dublin infections in dairy cattle. | in this study test characteristics of three newly developed enzyme-linked immunosorbent assays (elisas) for salmonella enterica subsp. enterica serovar dublin were evaluated and compared with two agglutination tests. the elisas involved were an indirect elisa with serovar dublin lipopolysaccharide (lps elisa), an indirect elisa with serovar dublin flagellar antigen (gp elisa), and a double-antibody sandwich blocking elisa that uses monoclonal antibodies against s. enterica subsp. enterica serova ... | 2000 | 11101571 |
| prevalence of diarrheagenic escherichia coli in finns with or without diarrhea during a round-the-world trip. | the incidence of diarrhea and the prevalence of bacterial enteropathogens, viruses, and parasites in feces of subjects with and without diarrhea were evaluated in 204 finns traveling round the world (from finland to china, malaysia, australia, fiji, chile, and brazil and back to finland). special emphasis was placed on the finding of diarrheagenic escherichia coli (enterotoxigenic, enteropathogenic, shiga toxin-producing, and enteroaggregative strains) by pcr from growth on primary culture plate ... | 2000 | 11101575 |
| characterization of chloramphenicol and florfenicol resistance in escherichia coli associated with bovine diarrhea. | florfenicol, a veterinary fluorinated analog of thiamphenicol, is approved for treatment of bovine respiratory pathogens in the united states. however, florfenicol resistance has recently emerged among veterinary escherichia coli isolates incriminated in bovine diarrhea. the flo gene, which confers resistance to florfenicol and chloramphenicol, has previously been identified in photobacterium piscicida and salmonella enterica serovar typhimurium dt104. the flo gene product is closely related to ... | 2000 | 11101601 |
| antimicrobial resistance of salmonella isolates from swine. | we examined the antimicrobial resistance of 1,257 isolates of 30 serovars of salmonella enterica subsp. enterica isolated from swine. serovars typhimurium and typhimurium var. copenhagen were widespread and were frequently multidrug resistant, with distinct resistance to ampicillin, kanamycin, streptomycin, sulfamethoxazole, and tetracycline and to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline, respectively. | 2000 | 11101609 |
| salmonella enterica serovar virchow with ctx-m-like beta-lactamase in spain. | four salmonella enterica serovar virchow strains resistant to broad-spectrum cephalosporins were isolated from patients with gastroenteritis in 1997 and 1998 in murcia and barcelona, spain. the isolates expressed a beta-lactamase with a pi of about 8 and a positive pcr when specific primers for ctx-m-9 were used. these results suggest the presence of a ctx-m-9 beta-lactamase in these strains. | 2000 | 11101623 |
| differential cytokine expression in avian cells in response to invasion by salmonella typhimurium, salmonella enteritidis and salmonella gallinarum. | salmonella enterica is a facultative intracellular pathogen that is capable of causing disease in a range of hosts. although human salmonellosis is frequently associated with consumption of contaminated poultry and eggs, and the serotypes salmonella gallinarum and salmonella pullorum are important world-wide pathogens of poultry, little is understood of the mechanisms of pathogenesis of salmonella in the chicken. type iii secretion systems play a key role in host cell invasiveness and trigger th ... | 2000 | 11101679 |
| invasiveness in chickens, stress resistance and rpos status of wild-type salmonella enterica subsp. enterica serovar typhimurium definitive type 104 and serovar enteritidis phage type 4 strains. | the heat and acid resistance and the ability to survive airdrying on commonly used kitchen surfaces were assessed for clinical and environmental strains of salmonella enterica subsp. enterica serovar typhimurium, definitive type (dt) 104. three out of thirty-eight strains of dt 104 were found to be more sensitive in stationary phase to the stresses examined than the other strains. this compares to a previous study by the authors which showed that seven out of forty serovar enteritidis phage type ... | 2000 | 11101680 |
| antibiotic resistance in salmonellae isolated from humans and animals in france: comparative data from 1994 and 1997. | among 25526 recorded isolates of salmonellae, 5086 isolated from humans and 20440 from animals in 1994 and 1997 in france, the antibiotic resistance phenotype was determined for all human and 5336 animal isolates. in salmonella enterica serovar typhimurium, one of the two most frequently isolated serovars from humans as well as animals, resistance to ampicillin was observed in 61% of both human and animal isolates in 1994 and in 73% of human and 53% of animal isolates in 1997. during these perio ... | 2000 | 11102416 |
| a cross-sectional study on the prevalence of listeria monocytogenes and salmonella in new york dairy herds. | as part of our long-term objective of assessing risk for listeria monocytogenes and salmonella spp. in dairy herds, we carried out a cross-sectional study to determine the prevalence of the two organisms. the study population consisted of a sample of dairy herds enrolled in the quality milk promotion services at cornell during the period of april 1998 to march 1999. the sample was stratified by geographical region to assure representation. four hundred and four dairy farms were enrolled in the s ... | 2000 | 11104262 |
| coupling of flagellar gene expression to flagellar assembly in salmonella enterica serovar typhimurium and escherichia coli. | how do organisms assess the degree of completion of a large structure, especially an extracellular structure such as a flagellum? bacteria can do this. mutants that lack key components needed early in assembly fail to express proteins that would normally be added at later assembly stages. in some cases, the regulatory circuitry is able to sense completion of structures beyond the cell surface, such as completion of the external hook structure. in salmonella and escherichia coli, regulation occur ... | 2000 | 11104815 |
| salmonella typhimurium proliferates and establishes a persistent infection in the intestine of caenorhabditis elegans. | genetic analysis of host-pathogen interactions has been hampered by the lack of genetically tractable models of such interactions. we showed previously that the human opportunistic pathogen pseudomonas aeruginosa kills caenorhabditis elegans, that p. aeruginosa and c. elegans genes can be identified that affect this killing, and that most of these p. aeruginosa genes are also important for mammalian pathogenesis. here, we show that salmonella typhimurium as well as other salmonella enterica sero ... | 2000 | 11114525 |
| identification of residues involved in catalytic activity of the inverting glycosyl transferase wbbe from salmonella enterica serovar borreze. | synthesis of the o:54 o antigen of salmonella enterica is initiated by the nonprocessive glycosyl transferase wbbe, assigned to family 2 of the glycosyl transferase enzymes (gt2). gt2 enzymes possess a characteristic n-terminal domain, domain a. based on structural data from the gt2 representative spsa (s. j. charnock and g. j. davies, biochemistry 38:6380-6385, 1999), this domain is responsible for nucleotide binding. it possesses two invariant asp residues, the first forming a hydrogen bond to ... | 2001 | 11114903 |
| alternative pathways for siroheme synthesis in klebsiella aerogenes. | siroheme, the cofactor for sulfite and nitrite reductases, is formed by methylation, oxidation, and iron insertion into the tetrapyrrole uroporphyrinogen iii (uro-iii). the cysg protein performs all three steps of siroheme biosynthesis in the enteric bacteria escherichia coli and salmonella enterica. in either taxon, cysg mutants cannot reduce sulfite to sulfide and require a source of sulfide or cysteine for growth. in addition, cysg-mediated methylation of uro-iii is required for de novo synth ... | 2001 | 11114933 |
| methionine-to-cysteine recycling in klebsiella aerogenes. | in the enteric bacteria escherichia coli and salmonella enterica, sulfate is reduced to sulfide and assimilated into the amino acid cysteine; in turn, cysteine provides the sulfur atom for other sulfur-bearing molecules in the cell, including methionine. these organisms cannot use methionine as a sole source of sulfur. here we report that this constraint is not shared by many other enteric bacteria, which can use either cysteine or methionine as the sole source of sulfur. the enteric bacterium k ... | 2001 | 11114934 |
| host adapted serotypes of salmonella enterica. | 2000 | 11117946 | |
| evaluation of a serological salmonella mix-elisa for poultry used in a national surveillance programme. | a mix-elisa using lipopolysaccharide antigens from salmonella enterica serotype enteritidis and typhimurium was evaluated using samples collected over time in the danish salmonella surveillance programme for poultry. serological samples (n = 42,813) taken from broiler-breeder flocks after a year of bacteriological monitoring with negative results were used for calculating the flock and individual test specificities, which were 0.997 and 0.999, respectively. layer flocks from the table egg sector ... | 2000 | 11117948 |
| analysis of expression of flagella by salmonella enterica serotype typhimurium by monoclonal antibodies recognising both phase specific and common epitopes. | monoclonal antibodies specific for phase 1 ("i" antigen), phase 2 ("1,2" antigen) and common epitopes of the flagellins of salmonella enterica serotype typhimurium were raised. having confirmed their specificity, the monoclonal antibodies were used to develop semi-quantitative elisas in order to assess the relative expression of the two phases by strains of typhimurium. the majority of typhimurium strains representative of a wide cross-section of definitive types from animal and environmental so ... | 2001 | 11118742 |
| salmonella enterica serotype typhimurium elicits cross-immunity against a salmonella enterica serotype enteritidis strain expressing lp fimbriae from the lac promoter. | the biological significance of fimbrial phase variation in salmonella serotypes is currently unknown. exposure to long polar (lp) fimbriae of salmonella enterica serotype typhimurium results in selection against lpf phase on cells of serotype enteritidis during a subsequent challenge, suggesting that fimbrial phase variation may be a mechanism to evade cross-immunity between salmonella serotypes. this notion was tested by assessing the effect of an immune response against serotype typhimurium lp ... | 2001 | 11119507 |
| salmonella pathogenicity island 2 influences both systemic salmonellosis and salmonella-induced enteritis in calves. | we have used signature-tagged mutagenesis to identify mutants of the host-specific salmonella enterica serotype dublin which were avirulent in calves and/or balb/c mice. a mutant with a transposon insertion in the ssed gene of salmonella pathogenicity island 2 (spi-2), which encodes a putative secreted effector protein, was identified. this mutant was recovered from the bovine host but not from the murine host following infection with a pool of serotype dublin mutants. however, a pure inoculum o ... | 2001 | 11119526 |
| improved innate immunity of endotoxin-tolerant mice increases resistance to salmonella enterica serovar typhimurium infection despite attenuated cytokine response. | during infection with gram-negative bacteria, exposure of immune cells to lipopolysaccharide (lps) from the bacterial cell membrane induces a rapid cytokine response which is essential for the activation of host defenses against the invading pathogens. administration of lps to mice induces a state of hyporesponsiveness, or tolerance, characterized by reduced cytokine production upon subsequent lps challenge. in the model of experimental salmonella enterica serovar typhimurium infection of mice, ... | 2001 | 11119538 |
| aromatic compound-dependent brucella suis is attenuated in both cultured cells and mouse models. | the aroc gene of the facultative intracellular pathogen brucella suis was cloned and sequenced. the cloned aroc gene complements escherichia coli and salmonella enterica serovar typhimurium aroc mutants. a b. suis aroc mutant was found to be unable to grow in a defined medium without aromatic compounds. the mutant was highly attenuated in tissue culture (thp1 macrophages and hela cells) and murine virulence models. | 2001 | 11119550 |
| immunity against helicobacter pylori: significance of interleukin-4 receptor alpha chain status and gender of infected mice. | vaccination of interleukin-4 (il-4) receptor alpha (il-4ralpha) chain-deficient balb/c mice with helicobacter pylori urease and cholera toxin or with urease-expressing, live attenuated salmonella enterica serovar typhimurium cells revealed that protection against h. pylori infection is independent of il-4- or il-13-mediated signals. a comparison of male and female mice suggests a sexual dimorphism in the extent of bacterial colonization that is particularly evident in the absence of the il-4ralp ... | 2001 | 11119552 |
| a soxrs-constitutive mutation contributing to antibiotic resistance in a clinical isolate of salmonella enterica (serovar typhimurium). | the soxrs regulon is activated by redox-cycling drugs such as paraquat and by nitric oxide. the >15 genes of this system provide resistance to both oxidants and multiple antibiotics. an association between clinical quinolone resistance and elevated expression of the soxrs regulon has been observed in escherichia coli, but this association has not been explored for other enteropathogenic bacteria. here we describe a soxrs-constitutive mutation in a clinical strain of salmonella enterica (serovar ... | 2001 | 11120941 |
| comparison of the escherichia coli k-12 genome with sampled genomes of a klebsiella pneumoniae and three salmonella enterica serovars, typhimurium, typhi and paratyphi. | the escherichia coli k-12 genome (eco) was compared with the sampled genomes of the sibling species salmonella enterica serovars typhimurium, typhi and paratyphi a (collectively referred to as sal) and the genome of the close outgroup klebsiella pneumoniae (kpn). there are at least 160 locations where sequences of >400 bp are absent from eco but present in the genomes of all three sal and 394 locations where sequences are present in eco but close homologs are absent in all sal genomes. the 394 s ... | 2000 | 11121489 |
| fis, a dna nucleoid-associated protein, is involved in salmonella typhimurium spi-1 invasion gene expression. | the ability of salmonella enterica serovar typhimurium to cause disease depends upon the co-ordinated expression of many genes located around the salmonella chromosome. specific pathogenicity loci, termed salmonella pathogenicity islands, have been shown to be crucial for the invasion and survival of salmonella within host cells. salmonella pathogenicity island 1 (spi-1) harbours the genes required for the stimulation of salmonella uptake across the intestinal epithelia of the infected host. reg ... | 2001 | 11123690 |
| induction of early immunopotentiation to fimbriae of salmonella enteritidis (se) by administering thymulin and zinc to se-vaccinated chicken breeders: relationship to protection. | the purpose of this study is to attempt the induction of early immunopotentiation of antibodies specific to fimbriae of salmonella enterica serovar enteritidis (se), by administering thymulin and zinc to se-vaccinated chicken breeders, and the improvement of protection against a controlled-live challenge by se. the first two groups of breeders were administered subcutaneously at 15 and 19 weeks of age a killed se vaccine. breeders of the third and fourth groups were left unvaccinated. breeders o ... | 2000 | 11129855 |
| development and optimization of a novel immunomagnetic separation- bacteriophage assay for detection of salmonella enterica serovar enteritidis in broth. | salmonella is the second-leading cause of food-borne illness in most developed countries, causing diarrhea, cramps, vomiting, and often fever. many rapid methods are available for detection of salmonella in foods, but these methods are often insensitive or expensive or require a high degree of technical ability to perform. in this paper we describe development and characterization of a novel assay that utilizes the normal infection cycle of bacteriophage sj2 for detection of salmonella enterica ... | 2001 | 11133448 |
| inactivation of gram-negative bacteria by lysozyme, denatured lysozyme, and lysozyme-derived peptides under high hydrostatic pressure. | we have studied the inactivation of six gram-negative bacteria (escherichia coli, pseudomonas fluorescens, salmonella enterica serovar typhimurium, salmonella enteritidis, shigella sonnei, and shigella flexneri) by high hydrostatic pressure treatment in the presence of hen egg-white lysozyme, partially or completely denatured lysozyme, or a synthetic cationic peptide derived from either hen egg white or coliphage t4 lysozyme. none of these compounds had a bactericidal or bacteriostatic effect on ... | 2001 | 11133464 |
| relative distribution and conservation of genes encoding aminoglycoside-modifying enzymes in salmonella enterica serotype typhimurium phage type dt104. | pcr was used to identify genes encoding aminoglycoside-modifying enzymes in 422 veterinary isolates of salmonella enterica serotype typhimurium. the identities of extra-integron genes encoding resistance to streptomycin, gentamicin, kanamycin, and apramycin were evaluated. gentamicin resistance was conferred by the aadb gene. kanamycin resistance was encoded by either the apha1-iab gene or the kn gene. apramycin resistance was determined by the aacc4 gene. analysis of gene distribution did not r ... | 2001 | 11133477 |
| application of rapid dot blot immunoassay for detection of salmonella enterica serovar enteritidis in eggs, poultry, and other foods. | salmonella enterica serovar enteritidis was detected in artificially inoculated eggs within 24 h through a rapid monoclonal antibody-based dot blot immunoassay. detection in poultry and other products required 28 h. samples were directly enriched in homogenized egg without the need for pre- or postenrichment steps. serovar enteritidis was detected in the presence of other bacteria when outcompeted 1:400. | 2001 | 11133480 |
| fimw is a negative regulator affecting type 1 fimbrial expression in salmonella enterica serovar typhimurium. | type 1 fimbriae are proteinaceous surface appendages that carry adhesins specific for mannosylated glycoproteins. these fimbriae are found on most members of the family enterobacteriaceae and are known to facilitate binding to a variety of eukaryotic cells, including those found on the mucosal surfaces of the alimentary tract. we have shown that the regulation of type 1 fimbrial expression in salmonella enterica serovar typhimurium is controlled, in part, by the products of four genes found with ... | 2001 | 11133935 |
| characterization of grva, an antivirulence gene on the gifsy-2 phage in salmonella enterica serovar typhimurium. | the lambdoid phage gifsy-2 contributes significantly to salmonella enterica serovar typhimurium virulence. the phage carries the periplasmic superoxide dismutase gene, sodci, and other unidentified virulence factors. we have characterized the gene grva, a single open reading frame inserted in the opposite orientation in the tail operon of the gifsy-2 phage. contrary to what is observed with classic virulence genes, grva null mutants were more virulent than wild type as measured by intraperitonea ... | 2001 | 11133955 |
| diversity of strains of salmonella enterica serotype enteritidis from english poultry farms assessed by multiple genetic fingerprinting. | reliable and sufficiently discriminative methods are needed for differentiating individual strains of salmonella enterica serotype enteritidis beyond the phenotypic level; however, a consensus has not been reached as to which molecular method is best suited for this purpose. in addition, data are lacking on the molecular fingerprinting of serotype enteritidis from poultry environments in the united kingdom. this study evaluated the combined use of classical methods (phage typing) with three well ... | 2001 | 11136764 |
| fluorescent amplified-fragment length polymorphism subtyping of the salmonella enterica serovar enteritidis phage type 4 clone complex. | fluorescent amplified-fragment length polymorphism (faflp) analysis, a high-resolution pcr-based genome fingerprinting method, was used to subtype salmonella enterica serovar enteritidis phage type 4. this single phage type is responsible for the majority of salmonellosis in europe. twenty strains isolated from nine outbreaks, five isolates from sporadic cases of human infection, four strains of poultry origin, and one laboratory-derived strain were comparatively studied by pulsed-field gel elec ... | 2001 | 11136771 |
| the emergence and spread of antibiotic resistance in food-borne bacteria. | since the early 1990s there has been a dramatic increase in resistance to antimicrobial drugs in salmonella enterica and campylobacter spp., and to a lesser extent in vero cytotoxin-producing escherichia coli o157 from cases of human infection in developed countries. for s. typhimurium a particularly important aspect of this increase has been the widespread dissemination of a multiply drug-resistant (mr) strain of definitive phage type (dt) 104 in food animals since the early 1990s. the use of a ... | 2000 | 11139009 |
| porins and lipopolysaccharide induce apoptosis in human spermatozoa. | treatment of human spermatozoa with porins or lipopolysaccharide (lps) increases spontaneous apoptosis in these cells. porins and lps were extracted from salmonella enterica serovar typhimurium and pasteurella multocida and were mixed with human spermatozoa for detection of levels of apoptosis. | 2001 | 11139223 |
| conserved regulatory elements of the promoter sequence of the gene rpoh of enteric bacteria. | the rpoh regulatory region of different members of the enteric bacteria family was sequenced or downloaded from genbank and compared. in addition, the transcriptional start sites of rpoh of yersinia frederiksenii and proteus mirabilis, two distant members of this family, were determined. sequences similar to the sigma(70) promoters p1, p4 and p5, to the sigma(e) promoter p3 and to boxes dnaa1, dnaa2, camp receptor protein (crp) boxes crp1, crp2 and box cytr present in escherichia coli k12, were ... | 2001 | 11139607 |
| the fliu and fliv genes are expressed as a single orf in salmonella choleraesuis. | a dna fragment carrying flagellar genes was cloned from salmonella choleraesuis. compared to the corresponding dna fragment of salmonella muenchen, this fragment contained three orfs instead of four shown in s. muenchen. the dna sequence data showed that there was an insertion of nucleotide c in the orf of the s. choleraesuis fliu gene, which resulted in the disappearance of a termination codon downstream. the recombinant plasmid pfu11 containing the coding region of the fliu gene made by pcr on ... | 2000 | 11142406 |
| new insights into endotoxin-induced activation of macrophages: involvement of a k+ channel in transmembrane signaling. | lps (endotoxins) activate cells of the human immune system, among which are monocytes and macrophages, to produce endogenous mediators. these regulate the immune response, but may also cause severe harm leading to septic shock. the activation of monocytes/macrophages by lps is mediated by a membrane-bound lps receptor, mcd14. as mcd14 lacks a transmembrane domain, a further protein is required for the signal transducing step to the cell interior. here we show, using excised outside-out membrane ... | 2001 | 11145680 |
| data-quality issues and alternative variable-screening methods in a questionnaire-based study on subclinical salmonella enterica infection in danish pig herds. | our aim was to determine risk factors for subclinical salmonella enterica infection in danish finishing-pig herds. in this paper, the evaluation, combining and initial reduction of variables is presented, along with assessment of the hypotheses in the preliminary statistical testing. the first group of herds was selected at random with no former knowledge of s. enterica infection. both the herd prevalence and the within-herd prevalence among these herds turned out to be low; hence, some addition ... | 2001 | 11150633 |
| genetic mapping by duplication segregation in salmonella enterica. | mudp and mudq elements were used to induce duplications in salmonella enterica by formation of a triple crossover between two transduced fragments and the host chromosome. the large size (36 kb) of mudp and mudq is a favorable trait for duplication formation, probably because homology length is a limiting factor for the central crossover. additional requirements are a multiplicity of infection of 2 or higher in the infecting phage suspensions (which reflects the need of two transduced fragments) ... | 2001 | 11156973 |
| genetic analysis of assembly of the salmonella enterica serovar typhimurium type iii secretion-associated needle complex. | several pathogenic bacteria have evolved a specialized protein secretion system termed type iii to secrete and deliver effector proteins into eukaryotic host cells. salmonella enterica serovar typhimurium uses one such system to mediate entry into nonphagocytic cells. this system is composed of more than 20 proteins which are encoded within a pathogenicity island (spi-1) located at centisome 63 of its chromosome. a subset of these components form a supramolecular structure, termed the needle com ... | 2001 | 11157927 |
| one of two hemn genes in bradyrhizobium japonicum is functional during anaerobic growth and in symbiosis. | previously, we screened the symbiotic gene region of the bradyrhizobium japonicum chromosome for new nifa-dependent genes by competitive dna-rna hybridization (a. nienaber, a. huber, m. göttfert, h. hennecke, and h. m. fischer, j. bacteriol. 182:1472-1480, 2000). here we report more details on one of the genes identified, a hemn-like gene (now called hemn(1)) whose product exhibits significant similarity to oxygen-independent coproporphyrinogen iii dehydrogenases involved in heme biosynthesis in ... | 2001 | 11157943 |
| sige is a chaperone for the salmonella enterica serovar typhimurium invasion protein sigd. | sigd is translocated into eucaryotic cells by a type iii secretion system. in this work, evidence that the putative chaperone sige directly interacts with sigd is presented. a bacterial two-hybrid system demonstrated that sige can interact with itself and sigd. in addition, sigd was specifically copurified with sige-his(6) on a nickel column. | 2001 | 11157959 |
| ompc is the receptor for gifsy-1 and gifsy-2 bacteriophages of salmonella. | mutations in the salmonella enterica serovar typhimurium ompc gene conferred resistance to gifsy-1 and gifsy-2 bacteriophages. selection for complementing plasmids yielded clones of ompc. introduction of an ompc clone into escherichia coli conferred the ability to adsorb gifsy phage. these data show that ompc is the receptor for gifsy-1 and gifsy-2 phages. | 2001 | 11157969 |
| characterization of extended-spectrum beta-lactamase (tem-52)-producing strains of salmonella enterica serovar typhimurium with diverse resistance phenotypes. | two salmonella enterica serovar typhimurium strains from different clonal origins, both producing an extended-spectrum beta-lactamase (tem-52), were isolated from a patient. this enzyme was encoded on a single plasmid and was found at very low levels in one strain, while being encoded on multiple plasmids and in multiple different ecori fragments in the other strain. | 2001 | 11158154 |
| salmonella pathogenicity island 2-encoded proteins ssec and ssed are essential for virulence and are substrates of the type iii secretion system. | survival of salmonella enterica serovar typhimurium within host phagocytic cells is a critical step in establishing systemic infection in mice. genes within salmonella pathogenicity island 2 (spi-2) encode a type iii secretion system that is required for establishment of systemic infection. several proteins encoded by spi-2 have homology to type iii secreted proteins from enteropathogenic escherichia coli and yersinia and, based on that homology, are predicted to be secreted through the spi-2 ty ... | 2001 | 11159962 |
| gene discovery through genomic sequencing of brucella abortus. | brucella abortus is the etiological agent of brucellosis, a disease that affects bovines and human. we generated dna random sequences from the genome of b. abortus strain 2308 in order to characterize molecular targets that might be useful for developing immunological or chemotherapeutic strategies against this pathogen. the partial sequencing of 1,899 clones allowed the identification of 1,199 genomic sequence surveys (gsss) with high homology (blast expect value < 10(-5)) to sequences deposite ... | 2001 | 11159979 |
| expression, extracellular secretion, and immunogenicity of the plasmodium falciparum sporozoite surface protein 2 in salmonella vaccine strains. | deleting transmembrane alpha-helix motifs from plasmodium falciparum sporozoite surface protein (ssp-2) allowed its secretion from salmonella enterica serovar typhimurium sl3261 and s. enterica serovar typhi cvd 908-htra by the hly type i secretion system. in mice immunized intranasally, serovar typhimurium constructs secreting ssp-2 stimulated greater gamma interferon splenocyte responses than did nonsecreting constructs (p = 0.04). | 2001 | 11160021 |
| mice lacking interleukin-2 (il-2)/il-15 receptor beta chain are susceptible to infection with avirulent salmonella enterica subsp. enterica serovar choleraesuis but mice lacking il-2 are resistant. | interleukin-2 (il-2)/il-15 receptor beta (il-15r beta)(-/-) mice were susceptible to infection with avirulent salmonella enterica subsp. enterica serovar choleraesuis, whereas il-2(-/-) mice were resistant. a natural killer cell response was not evident for both types of deficient mice. a th1 response was detected in il-2(-/-) but not in il-2/il-15r beta(-/-) mice infected with salmonella, suggesting that il-2/il-15r beta signaling is important for the generation of protective th1 cells. | 2001 | 11160028 |
| functional genomic, biochemical, and genetic characterization of the salmonella pduo gene, an atp:cob(i)alamin adenosyltransferase gene. | salmonella enterica degrades 1,2-propanediol by a pathway dependent on coenzyme b12 (adenosylcobalamin [adocb1]). previous studies showed that 1,2-propanediol utilization (pdu) genes include those for the conversion of inactive cobalamins, such as vitamin b12, to adocbl. however, the specific genes involved were not identified. here we show that the pduo gene encodes a protein with atp:cob(i)alamin adenosyltransferase activity. the main role of this protein is apparently the conversion of inacti ... | 2001 | 11160088 |
| the apee gene of salmonella enterica serovar typhimurium is induced by phosphate limitation and regulated by phobr. | mutations in aper, a regulatory locus of the outer membrane esterase apee from salmonella enterica serovar typhimurium, were shown to be alleles of the pstscab-phou high-affinity phosphate transport operon. expression of apee was induced by phosphate limitation, and this induction required the phobr phosphate regulatory system. | 2001 | 11160112 |
| characterization of the catalytic activities of the phoq histidine protein kinase of salmonella enterica serovar typhimurium. | studies of escherichia coli membranes that were highly enriched in the salmonella enterica serovar typhimurium phoq protein showed that the presence of atp and divalent cations such as mg2+, mn2+, ca2+, or ba2+ resulted in phoq autophosphorylation. however, when mg2) or mn2+ was present at concentrations higher than 0.1 mm, the kinetics of phoq autophosphorylation were strongly biphasic, with a rapid autophosphorylation phase followed by a slower dephosphorylation phase. a fusion protein lacking ... | 2001 | 11160113 |
| a flagellar gene fliz regulates the expression of invasion genes and virulence phenotype in salmonella enterica serovar typhimurium. | we previously reported that the fliz gene encodes a positive regulatory factor for the class 2 flagellar operons in salmonella enterica serovar typhimurium. in this study, we found that the fliz mutation reduced not only the amounts of excreted flagellar proteins, but also those of several secreted invasion proteins encoded by the genes within salmonella pathogenicity island 1. using the lacz gene fused to a subset of virulence-associated genes, we show that this downregulation was caused by a d ... | 2001 | 11162188 |
| the best defense is a good offense--salmonella deploys an adp-ribosylating toxin. | the dramatic clinical manifestations of toxigenic infections such as cholera and diphtheria occur without substantial bacterial invasion. disease is mediated by the secretion of potent toxins that use adp-ribosylation as the catalytic mechanism underlying their action. adp-ribosylating toxins comprise a large family, including the cholera, diphtheria, pertussis and escherichia coli heat-labile (lt) toxins, and all produce disease by altering key metabolic processes after transfer of an adp-ribos ... | 2001 | 11166220 |
| novel use of anaerobically induced promoter, dmsa, for controlled expression of fragment c of tetanus toxin in live attenuated salmonella enterica serovar typhi strain cvd 908-htra. | the anaerobically induced promoter dmsa (pdmsa) was adapted to optimize in vivo expression of foreign antigens in attenuated salmonella enterica serovar typhi live vector vaccines cvd 908-htra. pdmsa from escherichia coli and two derivatives, pdmsa2 and pdmsa3 were cloned into a plasmid driving the expression of a gene encoding tetanus toxin fragment c. expression of fragment c varied from a low level induced by ptetdmsa, to moderate and high levels induced, respectively, by ptetdmsa2 and ptetdm ... | 2001 | 11166893 |
| high rate of resistance to nalidixic acid in salmonella enterica: its role as a marker of resistance to fluoroquinolones. | 2000 | 11168127 | |
| actin is adp-ribosylated by the salmonella enterica virulence-associated protein spvb. | the salmonella enterica virulence-associated protein spvb was recently shown to contain a carboxy-terminal mono(adp-ribosyl)transferase domain. we demonstrate here that the catalytic domain of spvb as well bacterial extracts containing full-length spvb modifies a 43 kda protein from macrophage-like j774-a.1 and epithelial mdck cells as shown by label transfer from [32p]-nicotinamide adenine dinucleotide (nad) to the 43 kda protein. when analysed by two-dimensional gel electrophoresis, the same p ... | 2001 | 11169102 |
| the insect endosymbiont sodalis glossinidius utilizes a type iii secretion system for cell invasion. | sodalis glossinidius is a maternally transmitted secondary endosymbiont residing intracellularly in tissues of the tsetse flies, glossina spp. in this study, we have used tn5 mutagenesis and a negative selection procedure to derive a s. glossinidius mutant that is incapable of invading insect cells in vitro and is aposymbiotic when microinjected into tsetse. this mutant strain harbors tn5 integrated into a chromosomal gene sharing high sequence identity with a type iii secretion system invasion ... | 2001 | 11172045 |
| use of molecular subtyping in surveillance for salmonella enterica serotype typhimurium. | because salmonella enterica serotype typhimurium is the most common serotype isolated from persons with salmonellosis in the united states, it is difficult to detect unusual clusters or outbreaks. to determine whether molecular subtyping could be useful in public health surveillance for s. enterica serotype typhimurium, the minnesota department of health initiated the routine use of pulsed-field gel electrophoresis (pfge) of isolates. | 2001 | 11172141 |
| molecular characterization of streptococcus pneumoniae type 4, 6b, 8, and 18c capsular polysaccharide gene clusters. | capsular polysaccharide (cps) is a major virulence factor in streptococcus pneumoniae. cps gene clusters of s. pneumoniae types 4, 6b, 8, and 18c were sequenced and compared with those of cps types 1, 2, 14, 19f, 19a, 23f, and 33f. all have the same four genes at the 5' end, encoding proteins thought to be involved in regulation and export. sequences of these genes can be divided into two classes, and evidence of recombination between them was observed. next is the gene encoding the transferase ... | 2001 | 11179285 |
| staphylococcus aureus and salmonella enterica serovar dublin induce tumor necrosis factor-related apoptosis-inducing ligand expression by normal mouse and human osteoblasts. | staphylococcus aureus and salmonella enterica serovar dublin invade osteoblasts and are causative agents of human bone disease. in the present study, we examined the ability of s. aureus and salmonella serovar dublin to induce the production of tumor necrosis factor-related apoptosis-inducing ligand (trail) by normal osteoblasts. normal mouse and human osteoblasts were cocultured with s. aureus or salmonella serovar dublin at different multiplicities of infection. following initial incubation an ... | 2001 | 11179330 |
| rat mannose-binding protein a binds cd14. | lipopolysaccharide (lps) has been known to induce inflammation by interacting with cd14, which serves as a receptor for lps. mannose-binding protein (mbp) belongs to the collectin subgroup of the c-type lectin superfamily, along with surfactant proteins sp-a and sp-d. we have recently demonstrated that sp-a modulates lps-induced cellular responses by interaction with cd14 (h. sano, h. sohma, t. muta, s. nomura, d. r. voelker, and y. kuroki, j. immunol. 163:387-395, 2000) and that sp-d also inter ... | 2001 | 11179331 |