Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| adoptive transfer of cd4+ t cells specific for subunit a of helicobacter pylori urease reduces h. pylori stomach colonization in mice in the absence of interleukin-4 (il-4)/il-13 receptor signaling. | protection in the murine model of helicobacter pylori infection may be mediated by cd4+ t cells, but the mechanism remains unclear. to better understand how protection occurs in this model, we generated and characterized h. pylori urease-specific cd4+ t cells from balb/c mice immunized with salmonella enterica serovar typhimurium expressing h. pylori urease (subunits a and b). the cd4+ t cells were found to be specific for subunit a (urea). upon antigen-specific stimulation, expression of interl ... | 2001 | 11179348 |
| antibiotic susceptibilities of salmonella enterica serovar typhi and s. enterica serovar paratyphi a isolated from patients in japan. | the antibiotic susceptibilities of 62 strains of salmonella enterica serovar typhi and 37 strains of s. enterica serovar paratyphi a were investigated with 18 antibiotics. eighteen s. enterica serovar typhi isolates and five s. enterica serovar paratyphi a isolates were resistant to one or more antimicrobial agents, among which 10 s. enterica serovar typhi isolates were nalidixic acid resistant and also showed decreased ciprofloxacin susceptibility. | 2001 | 11181390 |
| first human case of salmonella enterica serotype landwasser recovered from breast fluid. | 2000 | 11185066 | |
| [antibiotics for uncomplicated salmonella enteritis: are they useful? a critical consideration of the literature]. | this article, a version of an earlier publication (6), reviews the human and veterinary literature on the effect of anti-microbials on uncomplicated salmonella enteritis. the main conclusion is that there is no evidence for the widely held belief that anti-microbials prolong the time that salmonellae are shed. | 2000 | 11189906 |
| prevalence and polymorphism of genes encoding translocated effector proteins among clinical isolates of salmonella enterica. | pathogenic salmonella enterica strains are capable of causing local and/or systemic infections. they employ two type iii secretion systems to translocate an array of virulence-associated proteins (effector proteins) directly into the cytosol of target cells of the host. earlier data had shown that changes in the repertoire of translocated effector proteins may contribute to the adaptation of salmonella strains to new hosts and to the emergence of epidemic strains. using pcr and southern blot tec ... | 2000 | 11200542 |
| sequence analysis and distribution in salmonella enterica serovars of is3-like elements. | the genome of salmonella enterica serovar enteritidis was shown to possess three is3-like insertion elements, designated is1230a, b and c, and each was cloned and their respective deoxynucleotide sequences determined. mutations in elements is1230a and b resulted in frameshifts in the open reading frames that encoded a putative transposase to be inactive. is1230c was truncated at nucleotide 774 relative to is1230b and therefore did not possess the 3' terminal inverted repeat. the three is1230 der ... | 2000 | 11200543 |
| cell envelope mutants of pseudomonas putida: physiological characterization and analysis of their ability to survive in soil. | to generate mutants with altered lipopolysaccharides (lps) of the wild-type pseudomonas putida kt2442, we used the mini-tn5luxab-km transposon. a mutant was found among luminescent colonies and selected as a negative clone in enzyme-linked immunosorbent assay (elisa) with monoclonal antibody (mab) 7.3b, which recognizes the o-antigen of p. putida lps. the dna region of the lps mutant interrupted by the minitransposon insertion was cloned and sequenced. comparison of the deduced amino acid sequen ... | 1999 | 11207769 |
| expression of type 1 fimbriae (sef 21) of salmonella enterica serotype enteritidis in the early colonisation of the rat intestine. | the involvement of type 1 fimbriae in colonisation of the rat gastrointestinal tract in vivo was investigated with salmonella enterica serotype enteritidis la5 and a mutant of la5 denoted eav3 unable to elaborate type 1 fimbriae (sef 21). rats were given a single dose of la5 or eav3 or a 1:1 mixture of both. la5 was found in higher numbers in the stomach and small intestine than eav3 at 6 h after infection with a single strain, but not after 6 days. la5 did not out-compete eav3 when the strains ... | 2001 | 11211228 |
| a cdna encoding 3-deoxy-d-manno-oct-2-ulosonate-8-phosphate synthase of pisum sativum l. (pea) functionally complements a kdsa mutant of the gram-negative bacterium salmonella enterica. | recombinant plasmids encoding 3-deoxy-d-manno-oct-2-ulosonate-8-phosphate (kdo-8-p) synthase (kdsa; ec 4.1.2.16) were identified from a cdna library of pisum sativum l. (pea) by complementing a temperature-sensitive kdsa(ts) mutant of the gram-negative bacterium salmonella enterica. sequence analysis of several inserts revealed a central open reading frame encoding a protein of 290 amino acids with a high degree of amino acid sequence similarity to bacterial kdsa. the cdna was confirmed by ampli ... | 2000 | 11219578 |
| molecular characterization of global regulatory rna species that control pathogenicity factors in erwinia amylovora and erwinia herbicola pv. gypsophilae. | rsmb(ecc) specifies a nontranslatable rna regulator that controls exoprotein production and pathogenicity in soft rot-causing erwinia carotovora subsp. carotovora. this effect of rsmb(ecc) rna is mediated mostly by neutralizing the function of rsma(ecc), an rna-binding protein of e. carotovora subsp. carotovora, which acts as a global negative regulator. to determine the occurrence of functional homologs of rsmb(ecc) in non-soft-rot-causing erwinia species, we cloned the rsmb genes of e. amylovo ... | 2001 | 11222584 |
| multiple antibiotic resistance (mar) locus in salmonella enterica serovar typhimurium dt104. | in order to understand the role of the mar locus in salmonella with regard to multiple antibiotic resistance, cyclohexane resistance, and outer membrane protein f (ompf) regulation, a mara::gfp reporter mutant was constructed in an antibiotic-sensitive salmonella enterica serovar typhimurium dt104 background. salicylate induced mara, whereas a number of antibiotics, disinfectants, and various growth conditions did not. increased antibiotic resistance was observed upon salicylate induction, altho ... | 2001 | 11229910 |
| biological sensor for sucrose availability: relative sensitivities of various reporter genes. | a set of three sucrose-regulated transcriptional fusions was constructed. fusions p61rytir, p61rylac, and p61ryice contain the scrr sucrose repressor gene and the promoterless gfp, lacz, and inaz reporter genes, respectively, fused to the scry promoter from salmonella enterica serovar typhimurium. cells of erwinia herbicola containing these fusions are induced only in media amended with sucrose, fructose, or sorbose. while a large variation in sucrose-dependent reporter gene activity was observe ... | 2001 | 11229926 |
| serology of typhoid fever in an area of endemicity and its relevance to diagnosis. | currently, the laboratory diagnosis of typhoid fever is dependent upon either the isolation of salmonella enterica subsp. enterica serotype typhi from a clinical sample or the detection of raised titers of agglutinating serum antibodies against the lipopolysaccharide (lps) (o) or flagellum (h) antigens of serotype typhi (the widal test). in this study, the serum antibody responses to the lps and flagellum antigens of serotype typhi were investigated with individuals from a region of vietnam in w ... | 2001 | 11230418 |
| molecular typing and epidemiological study of salmonella enterica serotype typhimurium isolates from cattle by fluorescent amplified-fragment length polymorphism fingerprinting and pulsed-field gel electrophoresis. | one hundred twenty salmonella enterica serotype typhimurium strains, including 103 isolates from cattle gathered between 1977 and 1999 in the prefecture located on the northern-most island of japan, were analyzed by using fluorescent amplified-fragment length polymorphism (faflp) and pulsed-field gel electrophoresis (pfge) to examine the genotypic basis of the epidemic. among these strains, there were 17 faflp profiles that formed four distinct clusters (a, b, c, and d). isolates that belonged t ... | 2001 | 11230427 |
| isolation and characterization of a salmonella enterica serotype typhi variant and its clinical and public health implications. | we report the isolation and characterization of a member of the family enterobacteriaceae isolated from the gallbladder pus of a food handler. conventional biochemical tests suggested salmonella enterica serotype typhi, but the isolate agglutinated with poly(o), 2o, 9o, and vi salmonella antisera but not with poly(h) or any individual h salmonella antisera. 16s rrna gene sequencing showed that there were two base differences between the isolate and salmonella enterica serotype montevideo, four b ... | 2001 | 11230457 |
| evaluation of the components of a commercial probiotic in gnotobiotic mice experimentally challenged with salmonella enterica subsp. enterica ser. typhimurium. | vitacanis((r)), a probiotic preparation containing a lactobacillus acidophilus, an enterococcus faecium and a saccharomyces cerevisiae, has been developed for the prevention of intestinal disorders in dogs and cats. in the present study, these microorganisms were tested jointly or singly during experimental infection of gnotobiotic mice with salmonella typhimurium. four experimental groups consisting of animals given probiotics jointly or singly and a control group consisting of germfree mice we ... | 2001 | 11230939 |
| multidrug-resistant strains of salmonella enterica serotype typhi are genetically homogenous and coexist with antibiotic-sensitive strains as distinct, independent clones. | the goal of this study was to report the molecular analysis of antibiotic-sensitive and multidrug-resistant (mdr) strains of salmonella typhi, using pulsed-field gel electrophoresis (pfge), with a particular emphasis on the coexistence of these strains in a typhoid-endemic region of karachi, pakistan. | 2000 | 11231181 |
| the spread and antibiotic resistance of salmonella enterica serotype typhimurium dt104 in hungary. | comparison of phage types (pts) determined by felix and callow's and anderson's methods was performed testing 99 human strains of s. enterica serotype typhimurium (s. typhimurium) isolated in hungary. pt2 and pt2c--according to felix-callow--corresponded with anderson's dt104 in case of 39 strains out of 40. among 59 isolates belonging to other felix-callow's pts only one strain was found which was dt 104. similar unambiguous equalities could not be established between any other pts comparing th ... | 2001 | 11233703 |
| typhoid fever and genetic polymorphisms at the natural resistance-associated macrophage protein 1. | control of salmonella enterica serovar typhimurium (s. typhimurium) infection in the mouse model of typhoid fever is critically dependent on the natural resistance-associated macrophage protein 1 (nramp1). in this study, we examined the role of genetic polymorphisms in the human homologue, nramp1, in resistance to typhoid fever in southern vietnam. patients with blood-culture-confirmed typhoid fever and healthy control subjects were genotyped for 6 polymorphic markers within and near nramp1 on c ... | 2001 | 11237848 |
| molecular evolution of the gdp-mannose pathway genes (manb and manc) in salmonella enterica. | the evolutionary history of the gdp-mannose pathway in salmonella enterica was studied via sequencing manb and manc genes from 13 representative strains for o antigens containing mannose and/or sugar derivatives of gdp-d-mannose. in addition, colanic acid (ca) manb and manc genes were sequenced from selected strains, as the basis for a detailed comparison. interestingly, including the eight previously characterized o antigen gene clusters, 12 of the 21 s. enterica strains studied in total (each ... | 2001 | 11238967 |
| the crystal structure of dtdp-d-glucose 4,6-dehydratase (rmlb) from salmonella enterica serovar typhimurium, the second enzyme in the dtdp-l-rhamnose pathway. | l-rhamnose is a 6-deoxyhexose that is found in a variety of different glycoconjugates in the cell walls of pathogenic bacteria. the precursor of l-rhamnose is dtdp-l-rhamnose, which is synthesised from glucose- 1-phosphate and deoxythymidine triphosphate (dttp) via a pathway requiring four enzymes. significantly this pathway does not exist in humans and all four enzymes therefore represent potential therapeutic targets. dtdp-d-glucose 4,6-dehydratase (rmlb; ec 4.2.1.46) is the second enzyme in t ... | 2001 | 11243820 |
| global analysis of escherichia coli gene expression during the acetate-induced acid tolerance response. | the ability of escherichia coli to survive at low ph is strongly affected by environmental factors, such as composition of the growth medium and growth phase. exposure to short-chain fatty acids, such as acetate, proprionate, and butyrate, at neutral or nearly neutral ph has also been shown to increase acid survival of e. coli and salmonella enterica serovar typhimurium. to investigate the basis for acetate-induced acid tolerance in e. coli o157:h7, genes whose expression was altered by exposure ... | 2001 | 11244055 |
| altered pathway routing in a class of salmonella enterica serovar typhimurium mutants defective in aminoimidazole ribonucleotide synthetase. | in salmonella enterica serovar typhimurium, purine nucleotides and thiamine are synthesized by a branched pathway. the last known common intermediate, aminoimidazole ribonucleotide (air), is formed from formylglycinamidine ribonucleotide (fgam) and atp by air synthetase, encoded by the puri gene in s. enterica. reduced flux through the first five steps of de novo purine synthesis results in a requirement for purines but not necessarily thiamine. to examine the relationship between the purine and ... | 2001 | 11244062 |
| sira orthologs affect both motility and virulence. | the sira gene of salmonella enterica serovar typhimurium encodes a two-component response regulator of the fixj family that has a positive regulatory influence on the expression of type iii secretion genes involved with epithelial cell invasion and the elicitation of bovine gastroenteritis. sira orthologs in pseudomonas, vibrio, and erwinia control the expression of distinct virulence genes in these genera, but an evolutionarily conserved target of sira regulation has never been identified. in t ... | 2001 | 11244064 |
| salmonella host cell invasion emerged by acquisition of a mosaic of separate genetic elements, including salmonella pathogenicity island 1 (spi1), spi5, and sope2. | salmonella spp. possess a conserved type iii secretion system encoded within the pathogenicity island 1 (spi1; centisome 63), which mediates translocation of effector proteins into the host cell cytosol to trigger responses such as bacterial internalization. several translocated effector proteins are encoded in other regions of the salmonella chromosome. it remains unclear how this complex chromosomal arrangement of genes for the type iii apparatus and the effector proteins emerged and how the d ... | 2001 | 11244077 |
| the interaction of protein structure, selection, and recombination on the evolution of the type-1 fimbrial major subunit (fima) from escherichia coli. | fimbrial adhesins allow bacteria to interact with and attach to their environment. the bacteria possibly benefit from these interactions, but all external structures including adhesins also allow bacteria to be identified by other organisms. thus adhesion molecules might be under multiple forms of selection including selection to constrain functional interactions or evolve novel epitopes to avoid recognition. we address these issues by studying genetic diversity in the escherichia coli type-1 fi ... | 2001 | 11244580 |
| studies of the phenomenon of host adaptation in salmonella. | to study the phenomenon of host adaptation in salmonella, a mathematical model has been developed which permits a definition and experimental investigation of the specific interaction between the adapted serovar and the adequate host. after experimental infection using a mixture of equal parts of two salmonella strains, a and b, the bacterial concentrations ca and cb were determined in the organs of the animals infected. if an animal of species a and an animal of species b are infected with the ... | 2000 | 11244872 |
| chlortetracycline modulates acute phase response of ex vivo perfused pig livers, and inhibits tnf-alpha secretion by isolated kupffer cells. | tetracyclines have been shown to have anti-inflammatory effects in addition to their antimicrobial action. we investigated the effects of in vivo administration of chlortetracycline (ctc) on ex vivo perfused pig livers. the retention and clearance of salmonella choleraesuis, production of acute phase proteins c-reactive protein (crp), and haptoglobin (hpg) by whole livers were studied. the in vitro modulation by ctc of tnf-alpha secretion by pig kupffer cells (kc) was also studied. pigs were dos ... | 2001 | 11247048 |
| thermal inactivation of stationary-phase and acid-adapted escherichia coli o157:h7, salmonella, and listeria monocytogenes in fruit juices. | the heat resistance of stationary-phase and acid-adapted escherichia coli o157:h7, salmonella enterica (serotypes typhimurium, enteritidis, gaminara, rubislaw, and hartford), and listeria monocytogenes was evaluated in single-strength apple. orange, and white grape juices adjusted to ph 3.9. the heat resistance increased significantly (p < 0.05) after acid adaptation. salmonella had an overall lower heat resistance than the other pathogens. acid-adapted e. coli o157:h7 presented the highest heat ... | 2001 | 11252473 |
| induction of protective immunity against streptococcus mutans colonization after mucosal immunization with attenuated salmonella enterica serovar typhimurium expressing an s. mutans adhesin under the control of in vivo-inducible nirb promoter. | the purpose of the present study was to evaluate the effectiveness of an attenuated salmonella enterica serovar typhimurium vaccine strain expressing the saliva-binding region (sbr) of the streptococcus mutans antigen i/ii adhesin, either alone or linked with the mucosal adjuvant cholera toxin a2 and b subunits (cta2/b) and under the control of the anaerobically inducible nirb promoter, in inducing a protective immune response against s. mutans infection. balb/c mice were immunized by either the ... | 2001 | 11254570 |
| salmonella enterica serovar typhimurium induces cell death in bovine monocyte-derived macrophages by early sipb-dependent and delayed sipb-independent mechanisms. | it was previously demonstrated that salmonella enterica serovar typhimurium induces cell death with features of apoptosis in murine macrophages. mice infected with salmonella serovar typhimurium develop systemic disease without diarrhea, whereas the infection in cattle and in humans is localized and characterized by diarrhea. considering these clinical disease expression differences between mice and cattle, we investigated whether serovar typhimurium is cytotoxic for bovine macrophages. macropha ... | 2001 | 11254586 |
| complete dna sequence and comparative analysis of the 50-kilobase virulence plasmid of salmonella enterica serovar choleraesuis. | the complete nucleotide sequence of pkdsc50, a large virulence plasmid from salmonella enterica serovar choleraesuis strain rf-1, has been determined. we identified 48 of the open reading frames (orfs) encoded by the 49,503-bp molecule. pkdsc50 encodes a known virulence-associated operon, the spv operon, which is composed of genes essential for systemic infection by nontyphoidal salmonella. analysis of the genetic organization of pkdsc50 suggests that the plasmid is composed of several virulence ... | 2001 | 11254626 |
| curli fibers mediate internalization of escherichia coli by eukaryotic cells. | curli fibers are adhesive surface fibers expressed by escherichia coli and salmonella enterica that bind several host extracellular matrix and contact phase proteins and were assumed to have a role in pathogenesis. the results presented here suggest that one such role is internalization into host cells. an e. coli k-12 strain transformed with a low-copy vector containing the gene cluster encoding curli fibers (csg operon) was internalized by several lines of eukaryotic cells. the internalization ... | 2001 | 11254632 |
| multidrug resistance is mediated by large plasmids carrying a class 1 integron in the emergent salmonella enterica serotype [4,5,12:i:-]. | a multidrug-resistant salmonella enterica serotype [4,5,12:i:-] clone carried a class 1 integron harboring dfra12 and aada2 gene cassettes and bla(tem-1), aac(3)-iv, cmla1, and teta genes located in large plasmids of about 140 kb (carrying spv) or 120 kb (lacking spv). several segregants, lacking multidrug resistance, contained a plasmid smaller than the parental one and no longer hybridized with probes for the lost resistances. the genes mediating resistance to ampicillin, chloramphenicol, and ... | 2001 | 11257054 |
| restricted growth of ent(-) and tonb mutants of salmonella enterica serovar typhi in human mono mac 6 monocytic cells. | monocytes and macrophages are an important host defense in humans infected with salmonella enterica serovar typhi. bacterial ability to survive in these cells is therefore a crucial virulence characteristic of this pathogen. in this study, we demonstrate that growth of a salmonella enterica serovar typhi enterochelin synthesis mutant and a tonb mutant in the human monocyte cell line mono mac 6 is restricted compared to that of the parental wild-type ty2 strain. these results suggest that enteroc ... | 2001 | 11257540 |
| the salmonella spvb virulence gene encodes an enzyme that adp-ribosylates actin and destabilizes the cytoskeleton of eukaryotic cells. | adp-ribosylating enzymes, such as cholera and diphtheria toxins, are key virulence factors for a variety of extracellular bacterial pathogens but have not been implicated previously during intracellular pathogenesis. salmonella strains are capable of invading epithelial cells and localizing in macrophages during infection. the spvb virulence gene of salmonella is required for human macrophage cytotoxicity in vitro and for enhancing intracellular bacterial proliferation during infection. here, we ... | 2001 | 11260464 |
| identification of a non-haem catalase in salmonella and its regulation by rpos (sigmas). | we report the identification and functional analysis of katn, a gene encoding a non-haem catalase of salmonella enterica serotype typhimurium. katn, which is not present in escherichia coli, is located between the ycigfe and ycid e. coli homologues in the salmonella genome. its predicted protein product has a molecular weight of 31 826 da and is similar to the mn-catalases of lactobacillus plantarum and thermus spp. its product, katn, was visualized as a 37 kda protein in e. coli maxicells. a ka ... | 2001 | 11260470 |
| evolutionary adaptation to temperature. viii. effects of temperature on growth rate in natural isolates of escherichia coli and salmonella enterica from different thermal environments. | are enteric bacteria specifically adapted to the thermal environment of their hosts? in particular, do the optimal temperatures and thermal niches of the bacterial flora reflect seasonal, geographic, or phylogenetic differences in their hosts' temperatures? we examined these questions by measuring the relationship between the temperature-dependent growth rates of enteric bacteria in a free-living ectothermic host. we sampled two species of enteric bacteria (escherichia coli and salmonella enteri ... | 2001 | 11263744 |
| enhancement of translation by the epsilon element is independent of the sequence of the 460 region of 16s rrna. | the epsilon enhancer element is a pyrimidine-rich sequence that increases expression of t7 gene 10 and a number of escherichia coli mrnas during initiation of translation and inhibits expression of the recf mrna during elongation. based on its complementarity to the 460 region of 16s rrna, it has been proposed that epsilon exerts its enhancer activity by base pairing to this complementary rrna sequence. we have tested this model of enhancer action by constructing mutations in the 460 region of 1 ... | 2001 | 11266541 |
| virulent strains of salmonella enteritidis disrupt the epithelial barrier of caco-2 and hep-2 cells. | to confirm the existence in nature of salmonella enteritidis strains of different degrees of virulence and to elucidate the mechanisms underlying the effects of such strains on the epithelial barrier function, the consequences of infection of caco-2 cells and hep-2 cells with 15 s. enteritidis strains in a chicken infection model were examined. the more virulent strains of s. enteritidis, which are biofilm producers in adherence test medium, were able to disrupt hep-2 and caco-2 monolayers, as s ... | 2001 | 11271420 |
| antimicrobial drug resistance in non-typhoidal salmonellas from humans in england and wales in 1999: decrease in multiple resistance in salmonella enterica serotypes typhimurium, virchow, and hadar. | in 1999 the incidence of multiple drug resistance (to four or more antimicrobials) in non-typhoidal salmonellas from humans in england and wales fell in isolations of salmonella enterica serotypes typhimurium, virchow, and hadar. this fall has been most noticeable in s. typhimurium, where 59% of isolates were multiresistant compared to 81% in 1996. the main reason for this has been a 75% decline in isolations of multiply-resistant s. typhimurium definitive phage type (dt) 104 (mr dt104) since 19 ... | 2000 | 11272261 |
| hydrogen peroxide-forming nadh oxidase belonging to the peroxiredoxin oxidoreductase family: existence and physiological role in bacteria. | amphibacillus xylanus and sporolactobacillus inulinus nadh oxidases belonging to the peroxiredoxin oxidoreductase family show extremely high peroxide reductase activity for hydrogen peroxide and alkyl hydroperoxides in the presence of the small disulfide redox protein, ahpc (peroxiredoxin). in order to investigate the distribution of this enzyme system in bacteria, 15 bacterial strains were selected from typical aerobic, facultatively anaerobic, and anaerobic bacteria. ahpc-linked alkyl hydroper ... | 2001 | 11274101 |
| the alternative electron acceptor tetrathionate supports b12-dependent anaerobic growth of salmonella enterica serovar typhimurium on ethanolamine or 1,2-propanediol. | synthesis of cobalamin de novo by salmonella enterica serovar typhimurium strain lt2 and the absence of this ability in escherichia coli present several problems. this large synthetic pathway is shared by virtually all salmonellae and must be maintained by selection, yet no conditions are known under which growth depends on endogenous b12. the cofactor is required for degradation of 1,2-propanediol and ethanolamine. however, cofactor synthesis occurs only anaerobically, and neither of these carb ... | 2001 | 11274105 |
| yersinia pestis pfra shows biovar-specific differences and recent common ancestry with a salmonella enterica serovar typhi plasmid. | population genetic studies suggest that yersinia pestis, the cause of plague, is a clonal pathogen that has recently emerged from yersinia pseudotuberculosis. plasmid acquisition is likely to have been a key element in this evolutionary leap from an enteric to a flea-transmitted systemic pathogen. however, the origin of y. pestis-specific plasmids remains obscure. we demonstrate specific plasmid rearrangements in different y. pestis strains which distinguish y. pestis bv. orientalis strains from ... | 2001 | 11274119 |
| factors associated with salmonella shedding among equine colic patients at a veterinary teaching hospital. | to evaluate factors potentially associated with fecal salmonella shedding among equine patients hospitalized for colic at a veterinary teaching hospital and to determine the effects of probiotic treatment on fecal salmonella shedding and clinical signs. | 2001 | 11280409 |
| practical evaluation of molecular subtyping and phage typing in outbreaks of infection due to salmonella enterica serotype typhimurium. | identification and control of food-poisoning outbreaks due to salmonellosis depend on prompt microbiological diagnosis and subtyping to identify the causative strain. in australia, salmonella enterica subspecies enterica serotype typhimurium (s. typhimurium) is responsible for 40-70% of cases of human salmonellosis. phage typing is the usual method of subtyping s. typhimurium, but on its own, has limitations. we compared it with three molecular subtyping methods using 100 isolates of s. typhimur ... | 2001 | 11280612 |
| inhibition of a glucose-limited sequencing fed-batch culture of salmonella enterica serovar enteritidis by volatile fatty acids representative of the ceca of broiler chickens. | the effects of concentrations of volatile fatty acids on an anaerobic, glucose-limited, and ph-controlled growing culture of salmonella enterica serovar enteritidis were studied. suddenly increasing volatile fatty acids to the concentrations representative of the ceca of 15-day-old broiler chickens caused washout of serovar enteritidis. in contrast, a sudden increase to the volatile fatty acid concentrations representative of the ceca of younger broiler chickens caused a reduction in the biomass ... | 2001 | 11282661 |
| use of a lightcycler gyra mutation assay for rapid identification of mutations conferring decreased susceptibility to ciprofloxacin in multiresistant salmonella enterica serotype typhimurium dt104 isolates. | a lightcycler-based pcr-hybridization gyra mutation assay (gama) was developed to rapidly detect gyra point mutations in multiresistant (mr) salmonella enterica serotype typhimurium dt104 with decreased susceptibility to ciprofloxacin (mic, 0.25 to 1.0 mg/liter). ninety-two isolates (49 human, 43 animal) were tested with three individual oligonucleotide probes directed against an asp-87-to-asn (gac-->aac) mutation, an asp-87-to-gly (gac-->ggc) mutation, and a ser-83-to-phe (tcc-->ttc) mutation. ... | 2001 | 11283069 |
| quantitation of bacteria in bone marrow from patients with typhoid fever: relationship between counts and clinical features. | enteric fever is the only bacterial infection of humans for which bone marrow examination is routinely recommended. a prospective study of the concentrations of bacteria in the bone marrow and their relationship to clinical features was conducted with 120 vietnamese patients with suspected enteric fever, of whom 89 had confirmed typhoid fever. ninety-three percent of the salmonella enterica serovar typhi samples isolated were resistant to ampicillin, chloramphenicol, and co-trimoxazole. for 81 p ... | 2001 | 11283089 |
| cloning and characterisation of male in burkholderia pseudomallei. | no recombinant protein is available for serodiagnosis or skin test in the diagnosis of melioidosis. this report describes the cloning of the male gene, which encodes an immunogenic protein of burkholderia pseudomallei. bi-directional dna sequencing of male revealed that the gene contained a single open reading frame encoding 416 amino acid residues with a predicted molecular mass of 44.4 kda. blast analysis showed that the putative protein encoded by male is homologous to the maltose-binding pro ... | 2001 | 11289518 |
| bacterially induced activation of interleukin-18 in porcine intestinal mucosa. | interleukin (il)-18 is a cytokine with structural and functional properties similar to il-1beta and il-12, respectively. it is activated by caspase-1 cleavage, like il-1beta, and induces interferon (ifn)-gamma, like il-12. in order to study the role of il-18 in the immune response to infectious diseases of mucosal surfaces we cloned and expressed porcine il-18 and developed antibodies to the protein. porcine il-18 retains the caspase-1 cleavage site present in other mammalian il-18 proteins, but ... | 2001 | 11292528 |
| salmonella enterica serovar typhi possesses a unique repertoire of fimbrial gene sequences. | salmonella enterica serotype typhi differs from nontyphoidal salmonella serotypes by its strict host adaptation to humans and higher primates. since fimbriae have been implicated in host adaptation, we investigated whether the serotype typhi genome contains fimbrial operons which are unique to this pathogen or restricted to typhoidal salmonella serotypes. this study established for the first time the total number of fimbrial operons present in an individual salmonella serotype. the serotype typh ... | 2001 | 11292704 |
| flagellar phase variation of salmonella enterica serovar typhimurium contributes to virulence in the murine typhoid infection model but does not influence salmonella-induced enteropathogenesis. | although salmonella enterica serovar typhimurium can undergo phase variation to alternately express two different types of flagellin subunit proteins, fljb or flic, no biological function for this phenomenon has been described. in this investigation, we constructed phase-locked derivatives of s. enterica serovar typhimurium that expressed only fljb (termed locked-on) or flic (termed locked-off). the role of phase variation in models of enteric and systemic pathogenesis was then evaluated. there ... | 2001 | 11292720 |
| salmonella enterica serovar-host specificity does not correlate with the magnitude of intestinal invasion in sheep. | the colonization of intestinal and systemic tissues by salmonella enterica serovars with different host specificities was determined 7 days after inoculation of 1 to 2-month-old lambs. following oral inoculation, s. enterica serovars abortusovis, dublin, and gallinarum were recovered in comparable numbers from the intestinal mucosa, but serovar gallinarum was recovered in lower numbers than the other serovars from systemic sites. the pattern of bacterial recovery from systemic sites following in ... | 2001 | 11292728 |
| antibodies against listerial protein 60 act as an opsonin for phagocytosis of listeria monocytogenes by human dendritic cells. | human-monocyte-derived dendritic cells (modc) are very efficient in the uptake of listeria monocytogenes, a gram-positive bacterium which is an important pathogen in humans and animals causing systemic infections with symptoms such as septicemia and meningitis. in this work, we analyzed the influence of blood plasma on the internalization of l. monocytogenes into human modc and compared the uptake of l. monocytogenes with that of salmonella enterica serovar typhimurium and yersinia enterocolitic ... | 2001 | 11292729 |
| stable transfection of the bovine nramp1 gene into murine raw264.7 cells: effect on brucella abortus survival. | genetically based natural resistance to brucellosis in cattle provides for novel strategies to control zoonotic diseases. bovine nramp1, the homologue of a murine gene (bcg), has been identified as a major candidate for controlling the in vivo resistant phenotype. we developed an in vitro model for expression of resistance- and susceptibility-associated alleles of bovine nramp1 as stable transgenes under the regulatory control of the bovine nramp1 promoter in the murine raw264.7 macrophage cell ... | 2001 | 11292730 |
| disruption of the genes for clpxp protease in salmonella enterica serovar typhimurium results in persistent infection in mice, and development of persistence requires endogenous gamma interferon and tumor necrosis factor alpha. | the enteric pathogen salmonella enterica serovar typhimurium, similar to other facultative intracellular pathogens, has been shown to respond to the hostile conditions inside macrophages of the host organism by producing a set of stress proteins that are also induced by various environmental stresses. the stress-induced clpxp protease is a member of the atp-dependent proteases, which are known to be responsible for more than 90% of all proteolysis in escherichia coli. to investigate the contribu ... | 2001 | 11292737 |
| roles of hilc and hild in regulation of hila expression in salmonella enterica serovar typhimurium. | sequences between -332 and -39 upstream of the hila promoter are required for repression of hila. an unidentified repressor is thought to bind these upstream repressing sequences (urs) to inhibit hila expression. two arac-like transcriptional regulators encoded on salmonella pathogenicity island 1 (spi1), hilc and hild, bind to the urs to counteract the repression of hila. the urs is required for regulation of hila by osmolarity, oxygen, phop/phoq, and sira/bara. here, we show that fadd, fliz, p ... | 2001 | 11292791 |
| low-molecular-weight plasmid of salmonella enterica serovar enteritidis codes for retron reverse transcriptase and influences phage resistance. | retron reverse transcriptases are unusual procaryotic enzymes capable of synthesis of low-molecular-weight dna by reverse transcription. all of the so-far-described dna species synthesized by retron reverse transcriptases have been identified as multicopy single-stranded dna. we have shown that salmonella enterica serovar enteritidis is also capable of synthesis of the low-molecular-weight dna by retron reverse transcriptase. surprisingly, salmonella serovar enteritidis-produced low-molecular-we ... | 2001 | 11292805 |
| bap, a staphylococcus aureus surface protein involved in biofilm formation. | identification of new genes involved in biofilm formation is needed to understand the molecular basis of strain variation and the pathogenic mechanisms implicated in chronic staphylococcal infections. a biofilm-producing staphylococcus aureus isolate was used to generate biofilm-negative transposon (tn917) insertion mutants. two mutants were found with a significant decrease in attachment to inert surfaces (early adherence), intercellular adhesion, and biofilm formation. the transposon was inser ... | 2001 | 11292810 |
| in vitro conversion of propionate to pyruvate by salmonella enterica enzymes: 2-methylcitrate dehydratase (prpd) and aconitase enzymes catalyze the conversion of 2-methylcitrate to 2-methylisocitrate. | salmonella enterica serovar typhimurium lt2 catabolizes propionate through the 2-methylcitric acid cycle, but the identity of the enzymes catalyzing the conversion of 2-methylcitrate into 2-methylisocitrate is unclear. this work shows that the prpd gene of the prpbcde operon of this bacterium encodes a protein with 2-methylcitrate dehydratase enzyme activity. homogeneous prpd enzyme did not contain an iron-sulfur center, displayed no requirements for metal cations or reducing agents for activity ... | 2001 | 11294638 |
| typing of salmonella enterica subsp. enterica serovar mbandaka isolates. | recently, salmonella enterica subsp. enterica serovar mbandaka (s. mbandaka) has gained some importance in the epidemiology of salmonellosis in poland. since biotyping, resistance typing, and plasmid profiling were insufficient for strain differentiation, genome macrorestriction by means of pulse-field gel electrophoresis (pfge) was applied and proved to be the method of choice in s. mbandaka epidemiological studies. xbai and bcui macrorestriction produced 15 and 14 pulse-field profiles (pfp), r ... | 2001 | 11295334 |
| kinetic and mutagenic characterization of the chromosomally encoded salmonella enterica aac(6')-iy aminoglycoside n-acetyltransferase. | the chromosomally encoded aminoglycoside n-acetyltransferase, aac(6')-iy, from salmonella enterica confers resistance toward a number of aminoglycoside antibiotics. the structural gene was cloned and expressed and the purified enzyme existed in solution as a dimer of ca. 17 000 da monomers. acetyl-coa was the preferred acyl donor, and most therapeutically important aminoglycosides were substrates for acetylation. exceptions are those aminoglycosides that possess a 6'-hydroxyl substituent (e.g., ... | 2001 | 11297438 |
| synergy of histone-derived peptides of coho salmon with lysozyme and flounder pleurocidin. | recent research has identified endogenous cationic antimicrobial peptides as important factors in the innate immunity of many organisms, including fish. it is known that antimicrobial activity, as well as lysozyme activity, can be induced in coho salmon (oncorhynchus kisutch) mucus after exposure of the fish to infectious agents. since lysozyme alone does not have antimicrobial activity against vibrio anguillarum and aeromonas salmonicida, a four-step protein purification protocol was used to is ... | 2001 | 11302792 |
| bacteriophage-bacteriophage interactions in the evolution of pathogenic bacteria. | many bacteriophages carry virulence genes encoding proteins that play a major role in bacterial pathogenesis. recently, investigators have identified bacteriophage-bacteriophage interactions in the bacterial host cell that also contribute significantly to the virulence of bacterial pathogens. the relationships between the bacteriophages pertain to one bacteriophage providing a helper function for another, unrelated bacteriophage in the host cell. accordingly, these interactions can involve the m ... | 2001 | 11303502 |
| virulence in the chick model and stress tolerance of salmonella enterica serovar orion var. 15+. | three salmonella enterica serovar orion var. 15+ isolates of distinct provenance were tested for survival in various stress assays. all were less able to survive desiccation than a virulent s. enteritidis strain, with levels of survival similar to a rpos mutant of the s. enteritidis strain, whereas one isolate (f3720) was significantly more acid tolerant. the s. orion var. 15+ isolates were motile by flagellae and elaborated type-1 and curli-like fimbriae; surface organelles that are considered ... | 2001 | 11310449 |
| variation in clonality and antibiotic-resistance genes among multiresistant salmonella enterica serotype typhimurium phage-type u302 (mr u302) from humans, animals, and foods. | since 1990 multiresistant (mr) salmonella enterica serotype typhimurium definitive phage-type (dt) 104 (mr dt104) and closely related phage types have emerged as a worldwide health problem in humans and food animals. in this study the presence of the blacarb-2 (ampicillin), cmla (chloramphenicol), aada2 (streptomycin/spectinomycin), sul1 (sulphonamide), and tetg (tetracycline) resistance genes in isolates of one such phage type, u302, have been determined. in addition blatem primers have been us ... | 2001 | 11310799 |
| a synaptojanin-homologous region of salmonella typhimurium sigd is essential for inositol phosphatase activity and akt activation. | the ser-thr kinase akt is activated in epithelial cells by salmonella enterica serovar typhimurium. the bacterial effector sigd, which is translocated into host cells via the specialized type iii secretion system, is essential for akt activation. here, we investigated the inositol phospholipid substrate preferences of sigd. recombinant sigd preferentially dephosphorylated phosphatidylinositol 3,5-biphosphate and phosphatidylinositol 3,4,5-triphosphate over other phosphatidylinositol lipids. phos ... | 2001 | 11311241 |
| characterization of the muts-proximal region of the salmonella typhimurium spi-1 identifies a group of pathogenicity island-associated genes. | the virulence properties of salmonella enterica are largely encoded within a set of horizontally acquired gene blocks termed pathogenicity islands. one such pathogenicity island, spi-1, located at centisome 63 of the salmonella chromosome between the muts and fhla genes, encodes a type iii protein secretion system and an iron uptake system. we have characterized the muts-proximal border of this pathogenicity island and have identified two sets of genes, pigab and pigcd. all four genes have homol ... | 2001 | 11313135 |
| host microarray analysis reveals a role for the salmonella response regulator phop in human macrophage cell death. | bacterial pathogens manipulate host cells to promote pathogen survival and dissemination. we used a 22,571 human cdna microarray to identify host pathways that are affected by the salmonella enterica subspecies typhimurium phop gene, a transcription factor required for virulence, by comparing the expression profiles of human monocytic tissue culture cells infected with either the wild-type bacteria or a phoptn10 mutant strain. both wild-type and phoptn10 bacteria induced a common set of genes, m ... | 2001 | 11320214 |
| aspartic peptide hydrolases in salmonella enterica serovar typhimurium. | two well-characterized enzymes in salmonella enterica serovar typhimurium and escherichia coli are able to hydrolyze n-terminal aspartyl (asp) dipeptides: peptidase b, a broad-specificity aminopeptidase, and peptidase e, an asp-specific dipeptidase. a serovar typhimurium strain lacking both of these enzymes, however, can still utilize most n-terminal asp dipeptides as sources of amino acids, and extracts of such a strain contain additional enzymatic activities able to hydrolyze asp dipeptides. h ... | 2001 | 11325937 |
| detection of salmonellae in chicken feces by a combination of tetrathionate broth enrichment, capillary pcr, and capillary gel electrophoresis. | this report describes a rapid detection procedure for salmonellae from chicken feces by the combination of tetrathionate primary enrichment (preenrichment [pe])-bacterial lysis-capillary pcr and capillary gel electrophoresis. pure salmonella enterica serovar enteritidis 64k was reisolated and detected by capillary pcr after buffered peptone water and nutrient broth, tetrathionate broth base hajna (ttbh), and tetrathionate broth (ttb) preenrichments. when the same culture was mixed with intestina ... | 2001 | 11326006 |
| seroprevalence and antibiotic sensitivity of serotypes of salmonella enterica in greek pig herds. | blood samples were taken from 50 pigs in each of 59 farrow-to-finish production herds and from 40 pigs in each of four of five registered multiplying herds. samples of feed and faeces were also collected from 17 of the production herds and from the four multiplying herds. the sera were tested for antibodies to salmonella enterica by the danish mix-elisa, and the organisms were isolated, serotyped and sensitivity tested by standard techniques. the average within-herd seroprevalence was 3.4 per ce ... | 2001 | 11327648 |
| biological properties of lipid a isolated from flavobacterium meningosepticum. | the biological properties of the lipid a from flavobacterium meningosepticum, which we recently isolated and whose complete chemical structure has been determined (h. kato, t. iida, y. haishima, a. tanaka, and k. tanamoto. j. bacteriol. 180:3891--3899, 1998), were studied. the lipid a exhibited generally moderate activity compared to salmonella enterica subsp. enterica serovar abortus equi lipopolysaccharide (lps) used as a control in the assay systems tested; lethal toxicity in galactosamine-se ... | 2001 | 11329451 |
| soft tissue and cartilage infection by salmonella oranienburg in a healthy girl. | focal extraintestinal infections from nontyphoid salmonellae have increased in incidence during the past decade. typically, they are manifested as either osteomyelitis or meningitis as a complication of either bacteremia or enteric fever. isolated salmonellal soft tissue infections, however, are rare and occur mostly in adults with chronic underlying conditions such as human immunodeficiency virus (hiv) infection, diabetes mellitus, and cell-mediated immunity defects. we report a case of an othe ... | 2001 | 11332914 |
| flagellin expressed by live salmonella vaccine strains induces distinct antibody responses following delivery via systemic or mucosal immunization routes. | salmonella flagellin, expressed as flagella in live attenuated vaccine strains, elicits distinct systemic (igg) and secreted (iga) antibody responses in mice following delivery via mucosal (nasal/oral) or parenteral (intraperitoneal (i.p.)) immunization routes. reduced flagellin-specific antibodies were detected either systemically or locally following delivery of flagellated derivatives of aroa salmonella enterica serovar dublin sl1438 via the nasal route, the most effective mucosal site for ac ... | 2001 | 11335139 |
| the sef14 fimbrial antigen of salmonella enterica serovar enteritidis is encoded within a pathogenicity islet. | the dna sequence of the chromosomal gene cluster encoding the sef14 fimbriae of salmonella enterica serovar enteritidis was determined. five contiguous open reading frames, sefabcde, were identified. the sefe gene shared significant homology with arac-like positive regulators. serovar-associated virulence plasmid (sap) genes orf7,8,9 and pefi were identified immediately adjacent to the sef operon. the pefi gene encoded a putative regulator of the plasmid-encoded fimbrial antigen (pef) expression ... | 2001 | 11337139 |
| monitoring of transmission of salmonella enterica serovars in pigs using bacteriological and serological detection methods. | the standard method to detect salmonella positive pigs is bacteriological examination of the faeces, but in recent years the use of salmonella-elisa's have become available to screen pigs for serological evidence of infection. this study was conducted to monitor the transmission of five different salmonella enterica serovars (s. typhimurium, s. brandenburg, s. panama, s. livingstone, and s. goldcoast) in fattening pigs and to test the feasibility of salmonella-elisa, using seeder pigs as a mode ... | 2001 | 11337142 |
| an attempt to identify the evolutionary origin of a novel serotype of salmonella enterica isolated from harbour porpoises. | the isolation since 1991 of a new serotype of salmonella enterica (antigenic formula 4,12:a:-) from harbour porpoises (phocoena phocoena) at post-mortem examination raised the question of its evolutionary origin. representative strains of s. enterica serotype 4,12:a:- and strains of eight other serotypes of serogroup 04 with phase-1 flagellar antigen h 'a' were examined by ecori ribotyping, is200 fingerprinting and pcr-based profiling. statistical analysis of results of multiple typing showed th ... | 2001 | 11339248 |
| role of trehalose in growth at high temperature of salmonella enterica serovar typhimurium. | moderate osmolality can stimulate bacterial growth at temperatures near the upper limit for growth. we investigated the mechanism by which high osmolality enhances the thermotolerance of salmonella enterica serovar typhimurium, by isolating bacteriophage mudi1734-induced insertion mutations that blocked the growth-stimulatory effect of 0.2 m nacl at 45 degrees c. one of these mutations proved to be in the seqa gene (a regulator of initiation of dna synthesis). because this gene is cotranscribed ... | 2001 | 11344144 |
| identification and functional characterization of arylamine n-acetyltransferases in eubacteria: evidence for highly selective acetylation of 5-aminosalicylic acid. | arylamine n-acetyltransferase activity has been described in various bacterial species. bacterial n-acetyltransferases, including those from bacteria of the gut flora, may be involved in the metabolism of xenobiotics, thereby exerting physiopathological effects. we characterized these enzymes further by steady-state kinetics, time-dependent inhibition, and dna hybridization in 40 species, mostly from the human intestinal microflora. we report for the first time n-acetyltransferase activity in 11 ... | 2001 | 11344150 |
| fhua barrel-cork hybrids are active transporters and receptors. | the crystal structure of escherichia coli fhua reveals a beta-barrel domain that is closed by a globular cork domain. it has been assumed that the proton motive force of the cytoplasmic membrane through the interaction of the tonb protein with the tonb box of the cork opens the fhua channel. yet, deletion of the cork results in an fhua derivative, fhuadelta5-160, that still displays tonb-dependent substrate transport and phage receptor activity. to investigate this unexpected finding further, we ... | 2001 | 11344156 |
| epidemiological analysis of salmonella enterica serotype typhimurium from hong kong by ribotyping and pulsed-field gel electrophoresis. | we investigated the antimicrobial susceptibilities and molecular epidemiology of 200 strains of salmonella enterica serotype typhimurium isolated from 1989 to 1996 in hong kong. only 22% of strains were susceptible to all 19 antibiotics tested but all were susceptible to second- and third-generation cephalosporins. up to 9% of strains were resistant to 0.12 mg/l concentrations of ciprofloxacin or ofloxacin but none were resistant to 1 or 2 mg/l concentrations of these 2 drugs, respectively. the ... | 2001 | 11345219 |
| standardized laboratory-scale preparation of mayonnaise containing low levels of salmonella enterica serovar enteritidis. | salmonella enterica serovar enteritidis pt4 and pt6 are associated with food poisoning outbreaks and are often found in food only in low concentrations. in this study a reproducible laboratory-scale procedure for preparation of mayonnaise is presented. the mayonnaise that simulates a naturally low-level contaminated product can be used for validation of new methods and is also suitable to study the behavior of low numbers of food pathogenic spoilage microorganisms in a food environment. during p ... | 2001 | 11347990 |
| enhanced inhibition of listeria monocytogenes and salmonella enteritidis in meat by combinations of sodium lactate and diacetate. | the antimicrobial activities of sodium lactate (sl) and sodium acetate (sa) are well documented, but there is limited information on the effect of their combination or of the combination of sl and sodium diacetate (sda) on survival and growth of listeria monocytogenes and salmonellae in meat. effects of sl (1.8 and 2.5%), sda (0.1 and 0.2%), or sa (0.2%) and their combinations on the behavior of l monocytogenes and salmonella enterica serovar enteritidis were investigated in sterile comminuted b ... | 2001 | 11347993 |
| monitoring of layer feed and eggs for salmonella in eastern japan between 1993 and 1998. | in order to investigate contamination of chicken farms with salmonella, feed and eggs were sampled from 16 commercial layer farms in eastern japan between 1993 and 1998 and cultured for salmonellae. salmonella enterica subsp. enterica isolates belonging to 19 serovars were obtained from the feed. six of the 19 serotypes, including salmonella serovar enteritidis, were observed in isolates recovered from the eggs. salmonella serovar enteritidis strains obtained from a feed sample and egg contents ... | 2001 | 11348011 |
| the virulence for gnotobiotic pigs of live attenuated vaccine strains of salmonella enterica serovars typhimurium and enteritidis. | gnotobiotic pigs were inoculated orally with wild-type or defined aroa or cya crp vaccine strains of salmonella enterica serovars typhimurium and s. enteritidis. the parental strains were virulent, inducing severe diarrhoea, dehydration and systemic disease. the cya crp mutant was also highly virulent whereas the aroa strains were attenuated. | 2001 | 11348707 |
| intranasal immunogenicity of a deltacya deltacrp-paba mutant of salmonella enterica serotype typhimurium for the horse. | the aim of this study was to investigate the intranasal immunogenicity for the horse of a deltacya deltacrp-paba mutant (mgn-707) of salmonella enterica serotype typhimurium (s. typhimurium). mgn-707 caused no sign of disease, was not detected in feces and a single administration induced strong salmonella-specific serum and nasal mucosal antibody responses. all ponies had made strong salmonella specific serum igga, iggb, iga and igm antibody responses by day 25 after the first immunization. igm ... | 2001 | 11348727 |
| auxotrophic, plasmid-cured salmonella enterica serovar typhimurium for use as a live vaccine in calves. | calves were vaccinated orally, subcutaneously or intraperitoneally with a smooth, plasmid-cured strain of salmonella enterica serovar typhimurium, strain 81. oral vaccination was not effective, as only 1/5 calves survived challenge with virulent s. typhimurium. strain 81 was attenuated for calves, as only a slight rise in rectal temperatures was detected after vaccination. the organism was excreted by some calves in the faeces, but no signs of diarrhoea were observed after vaccination. after par ... | 2001 | 11348774 |
| lipopolysaccharide of burkholderia cepacia and its unique character to stimulate murine macrophages with relative lack of interleukin-1beta-inducing ability. | lipopolysaccharide (lps) of burkholderia cepacia was purified by the conventional phenol-water extraction method (preparation bclps-1), followed by enzymatic treatments with dnase, rnase, trypsin, and proteinase k (preparation bclps-2), and finally by deoxycholate-phenol-water extraction (preparation bclps-3). cells of lps-hyporesponsive c3h/hej mice were activated by both the bclps-1 and the bclps-2 preparations but barely activated by bclps-3. when lps-responsive c3h/hen mice were used as targ ... | 2001 | 11349028 |
| calprotectin expression inhibits bacterial binding to mucosal epithelial cells. | squamous mucosal epithelial cells constitutively express calprotectin in the cytoplasm. to study how this antimicrobial protein complex confers epithelial resistance to invading bacteria, an epithelial cell line was stably transfected to express the calprotectin complex. cells expressing calprotectin resist invasion by listeria monocytogenes and salmonella enterica serovar typhimurium. calprotectin expression was accompanied by altered actin organization, increased alpha3 integrin expression, an ... | 2001 | 11349032 |
| environmental survey of salmonella and comparison of genotypic character with human isolates in western japan. | to estimate the prevalence and distribution of salmonellae, especially salmonella enterica subsp. enterica serovar enteritidis (s. enteritidis), in western japan, an investigation was conducted of the chicken industry and environmental sources between 1995 and 1998. salmonellae were isolated from 34 of 90 samples (37.8%) of raw chicken parts, 34 of 98 faecal samples (34.7%) at 35 broiler farms, 11 of 59 samples (18.6%) of liquid eggs, and from 71 of 272 samples (26.1%) of swab specimens from equ ... | 2001 | 11349965 |
| investigation of the parasitic nematode ascaridia galli (shrank 1788) as a potential vector for salmonella enterica dissemination in poultry. | during recent years, the level of organically farmed poultry in denmark has increased. subsequent investigations have demonstrated an incidence of 64% of ascaridia galli infections in layers established in organic farming systems. studies to determine the interaction of salmonella enterica with the parasitic nematode a. galli associated with poultry were undertaken to establish the significance of a. galli in the dissemination of s. enterica. a. galli was isolated from 40-week-old lohmann brown ... | 2001 | 11355682 |
| intestinal mucosal immune response in chickens following intraocular immunization with liposome-associated salmonella enterica serovar enteritidis antigen. | induction of intestinal mucosal immune responses against salmonella enterica serovar enteritidis was studied by immunizing chickens with liposome-associated antigen. an ultrasonicated whole cell extract of the bacteria was used for immunizing antigen. intraocular immunization induced serum iga, igg and igm responses. also, significant iga and igg antibodies were detected in the intestinal tract. immunization with antigen alone induced only igg response in the intestine. salmonella enteritidis-sp ... | 2001 | 11356227 |
| salmonella group b meningitis 6 weeks after hospitalization in a neonatal care unit. | 2001 | 11358475 | |
| control of fimy translation and type 1 fimbrial production by the arginine trna encoded by fimu in salmonella enterica serovar typhimurium. | expression of type 1 fimbriae in salmonella enterica serovar typhimurium undergoes phase variation or alteration between a fimbriate and a non-fimbriate phenotype. this variation is known to be dependent upon environmental conditions in vitro and is thought to be a complex process involving regulation by a number of proteins. the regulatory genes located within the fim cluster include fimz, fimy and fimw. a fourth gene of the cluster, fimu, encodes a trna molecule specific for rare arginine codo ... | 2001 | 11359580 |
| evaluation of molecular typing methods for salmonella enterica serovar typhimurium dt104 isolated in germany from healthy pigs. | the discriminatory power of four different dna based typing methods was tested for the molecular subtyping of salmonella typhimurium phage type dt104 isolates. german dt104 strains (n = 133) originating from slaughter pigs were analysed by plasmid profiling, and 32 of them by pulsed-field gel electrophoresis (pfge) using the restriction enzymes xbai, spei or blni, random amplification of polymorphic dna (rapd) using 13 different primers and is200 typing. a resulting subtyping scheme was obtained ... | 2001 | 11361148 |
| virulence gene regulation in salmonella enterica. | in order to infect a host, a microbe must be equipped with special properties known as virulence factors. bacterial virulence factors are required to facilitate colonization, to survive under host defenses, and to permit multiplication inside the host. however, the possession of genes encoding virulence factors does not guarantee effective infection. there is considerable evidence that tight regulation of a given virulence factor is as important as the possession of the virulence factors themsel ... | 2001 | 11370771 |
| genetic characterization of the klebsiella pneumoniae waa gene cluster, involved in core lipopolysaccharide biosynthesis. | a recombinant cosmid containing genes involved in klebsiella pneumoniae c3 core lipopolysaccharide biosynthesis was identified by its ability to confer bacteriocin 28b resistance to escherichia coli k-12. the recombinant cosmid contains 12 genes, the whole waa gene cluster, flanked by kbl and coad genes, as was found in e. coli k-12. pcr amplification analysis showed that this cluster is conserved in representative k. pneumoniae strains. partial nucleotide sequence determination showed that the ... | 2001 | 11371519 |
| amplification of mutator cells in a population as a result of horizontal transfer. | mutator cells that lack the mismatch repair system (mmr(-)) occur at rates of 10(-5) or less in laboratory populations started from wild-type cells. we show that after selection for recombinants in an interspecies mating between salmonella enterica serovar typhimurium and escherichia coli, the percentage of mmr(-) cells rises to several percent of the recombinant population, and after a second successive mating and selection, greater than 95% of the recombinants are mmr(-). coupling a single cro ... | 2001 | 11371538 |