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regulation of spvr gene expression of salmonella virulence plasmid pkdsc50 in salmonella choleraesuis serovar choleraesuis.the expression regulation of spvr, a regulatory gene on the virulence plasmid (pkdsc50) of salmonella choleraesuis serovar choleraesuis, was investigated by spvr-lacz translational fusion. the spvr gene was found to be positively regulated by its own product, the spvr protein, and this unusual positive autoregulation was repressed by the products of spva and spvb, virulence-associated genes present downstream from the spvr gene. amino acid sequence analysis revealed that the amino-terminal regio ...19948052129
transcriptional regulation and promoter sequence of the spvr gene of virulence plasmid pkdsc50 in salmonella choleraesuis serovar choleraesuis.the transcript of the spvr gene on the virulence plasmid, pkdsc50, of salmonella choleraesuis serovar choleraesuis was detected for the first time by northern blot analysis, and the transcriptional regulation of the spvr gene was investigated. the transcription of the spvr was negatively regulated by spva and spvb, and enhanced at stationary phase under control of a sigma factor rpos (sigma 38). the spvr transcript was 2.4 kilonucleotides in salmonella cells, and deduced to encode spvr and spva, ...19957607404
molecular characterization of salmonella enterica subsp. enterica serovar choleraesuis field isolates and differentiation from homologous live vaccine strains suisaloral and sc-54.four independent molecular methods were used to characterize the salmonella enterica subsp. enterica serovar choleraesuis live vaccine strains sc-54 and suisaloral and to differentiate them from s. choleraesuis field isolates. plasmid analysis revealed the presence of seven plasmid profiles. a virulence plasmid of 52-kbp was identified by hybridization with an spvb-spvc gene probe in each of the s. choleraesuis field isolates and in the suisaloral vaccine strain, but not in the sc-54 vaccine str ...19968880500
attachment of salmonella choleraesuis choleraesuis to beef muscle and adipose tissues.the attachment of salmonella choleraesuis subsp. choleraesuis atcc 15790 to beef muscle and adipose tissues was investigated. s. choleraesuis was found to adhere in higher numbers to muscle than to fat. the charge and the hydrophobicity of the surface of s. choleraesuis were evaluated by measurement of electrophoretic mobility, the contact angle with water, adhesion to hexadecane, and hydrophobic interaction chromatography. the overall negative charge of s. choleraesuis was masked by the high el ...199710465034
comparative physical and genetic maps of the virulence plasmids of salmonella enterica serovars typhimurium, enteritidis, choleraesuis, and dublin.using fragment profiling, pcr, and southern hybridization, we found that salmonella enterica serovar choleraesuis harbored virulence plasmids of various sizes, whereas serovars typhimurium, enteritidis, and dublin carried a plasmid of a unique size. also, the virulence plasmid of typhimurium contained genes in the same order detected in the other three plasmids, all of which contained deletions.199910225928
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. ...200011063509
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 ...200111254626
large drug resistance virulence plasmids of clinical isolates of salmonella enterica serovar choleraesuis.salmonella enterica serovar choleraesuis generally causes systemic human salmonellosis without diarrhea, and therefore, antimicrobial treatment is essential for such patients. the drug resistance information on this organism is thus of high value. serovar choleraesuis usually harbors a virulence plasmid (pscv) of 50 kb in size. of the 16 clinical isolates identified to be serovar choleraesuis, all except one harbored a pscv and seven of them carried a pscv of more than 125 kb in size. a pscv was ...200111451688
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.200111160028
cloning and characterization of an iron regulated locus, iroa, in salmonella enterica serovar choleraesuis.to identify genes belonging to the ferric update regulator (fur) regulon of salmonella enterica serovar choleraesuis, the fur titration assay (furta) was used to screen a genomic library for fur promoters and iron-regulated genes. fifteen furta positive clones were identified from this assay. dna sequence analysis of these clones showed that 11 out of 15 clones had a fur binding site (fur box), and 6 of these clones showed homology to the iron-regulated genes of s. enterica serovar typhi and/or ...200212652904
systemic and enteric colonization of pigs by a hila signature-tagged mutant of salmonella choleraesuis.although host adapted to pigs, salmonella enterica serovar choleraesuis (s. choleraesuis) can induce a virulent foodborne salmonellosis in humans. to directly investigate virulence factors of s. choleraesuis, we extended the functional genomics approach of signature-tagged mutagenesis to s. choleraesuis and pigs. when a test pool of 45 randomly signature-tagged null mutants was inoculated orally and intraperitoneally in pigs, one of the mutants that failed to colonize by either route was tagged ...200312631476
comparison of fluoroquinolone resistance genes of salmonella enterica serovar choleraesuis isolates in japan and taiwan. 200415623959
sequence analysis and characterization of sulfonamide resistance plasmid prf-1 from salmonella enterica serovar choleraesuis.the nucleotide sequence of a small plasmid, designated prf-1, isolated from salmonella enterica serovar choleraesuis, was determined. we identified seven open reading frames (orfs) encoded by 6066 nucleotides with a total g + c content of 53.6%. analysis of the complete nucleotide sequence revealed a replicon of prf-1 to have high similarity to the p15a origin of replication, with a possible cer-like region. orf1, which is composed of 816 nucleotides, shows a high degree of similarity to dihydro ...200415518878
detection of mutations in the gyra gene and class i integron from quinolone-resistant salmonella enterica serovar choleraesuis isolates in taiwan.the quinolone resistance-determining regions (qrdrs) of the gyra gene of quinolone-resistant salmonella enterica serovar choleraesuis isolates were sequenced. four types of point mutation, ser-83-to-phe (tcc --> ttc), ser-83-to-tyr (tcc --> tac), asp-87-to-gly (gac --> ggc), and asp-87-to-asn (gac --> aac), were found. pcr-rflp and mas-touch down pcr were performed on fifty swine clinical isolates of s. enterica serovar choleraesuis (nalr) collected during 1997-2002. the analysis indicated seven ...200415145503
novel attenuated salmonella enterica serovar choleraesuis strains as live vaccine candidates generated by signature-tagged mutagenesis.salmonella enterica serovar choleraesuis is a host-adapted pathogen that causes swine paratyphoid. signature-tagged mutagenesis (stm) was used to understand the pathogenicity of s. enterica serovar choleraesuis in its natural host and also to develop novel attenuated live vaccine candidates against this disease. a library of 960 signature-tagged mutants of s. enterica serovar choleraesuis was constructed and screened for attenuation in pigs. thirty-three mutants were identified by the stm screen ...200516299315
epidemiologic relationship between fluoroquinolone-resistant salmonella enterica serovar choleraesuis strains isolated from humans and pigs in taiwan (1997 to 2002).the emergence of ciprofloxacin-resistant salmonella enterica serovar choleraesuis in recent years has become an important public health issue in taiwan. the resistant strains that cause human infections are considered to be from pigs. in this study, we characterized 157 swine and 42 human salmonella serovar choleraesuis isolates by pulsed-field gel electrophoresis (pfge) and drug susceptibility testing to investigate the epidemiologic relationship among the isolates. by pfge analyses, two major ...200515956400
the genome sequence of salmonella enterica serovar choleraesuis, a highly invasive and resistant zoonotic pathogen.salmonella enterica serovar choleraesuis (s. choleraesuis), a highly invasive serovar among non-typhoidal salmonella, usually causes sepsis or extra-intestinal focal infections in humans. s. choleraesuis infections have now become particularly difficult to treat because of the emergence of resistance to multiple antimicrobial agents. the 4.7 mb genome sequence of a multidrug-resistant s. choleraesuis strain sc-b67 was determined. genome wide comparison of three sequenced salmonella genomes revea ...200515781495
insertional mutation of mara vitiates inducible multiple antimicrobial resistance in salmonella enterica subsp. enterica serovar choleraesuis.mara has been shown to mediate a multiple antimicrobial resistance (mar) phenotype following induction in some members of the enterobacteriaceae. when salmonella choleraesuis was exposed to inducing agents they displayed higher minimal inhibitory concentrations (mic) to multiple antimicrobial agents and an increase in mara expression as determined by northern hybridization analysis. the objective of the present study was to determine if mutation of mara vitiated multiple antimicrobial resistance ...200516006078
differential contribution of sodc1 and sodc2 to intracellular survival and pathogenicity of salmonella enterica serovar choleraesuis.several of the most virulent salmonella enterica strains possess two genes encoding periplasmic cu,zn superoxide dismutase, sodc1 and sodc2, located on a lambdoid prophage and on the chromosome, respectively. these genes contribute to salmonella virulence by protecting bacteria from superoxide generated by the host's phagocytes. to investigate the respective contributions of sodc1 and sodc2 to the virulence of a clinical isolate of salmonella enterica serovar choleraesuis (s. choleraesuis), we h ...200515823516
identification of the outer-membrane protein pagc required for the serum resistance phenotype in salmonella enterica serovar choleraesuis.serum resistance is a crucial virulence factor for the development of systemic infections, including bacteraemia, by many pathogenic bacteria. salmonella enterica serovar choleraesuis is an important enteric pathogen that causes serious systemic infections in swine and humans. here, it was found that, when introduced into escherichia coli, a recombinant plasmid carrying the pagc gene from a plasmid-based genomic library of s. enterica serovar choleraesuis conferred a high-level resistance to the ...200515758232
development of pcr primers for the detection of salmonella enterica serovar choleraesuis based on the flic gene.salmonella enterica serovar choleraesuis may cause swine salmonellosis and human infection. because the conventional method for detection of this salmonella serovar may take 3 to 5 days, a pcr method for detection was evaluated. by comparing the sequence of the phase 1 flagellin (flic) gene of salmonella choleraesuis with that of other salmonella serovars and of other bacteria species available in genbank, two pcr primers (flinc-f and flinc-r) were designed. using these primers, all 97 salmonell ...200521132962
characterisation of antimicrobial resistance patterns and class 1 integrons among escherichia coli and salmonella enterica serovar choleraesuis strains isolated from humans and swine in taiwan.escherichia coli isolates from humans (n=110) and swine (n=61) and salmonella enterica serovar choleraesuis isolates (n=95) from swine in southern taiwan were characterised for antimicrobial resistance patterns and class 1 integrons. all e. coli isolates and s. choleraesuis isolates were multidrug resistant and demonstrated high resistance to beta-lactams, aminoglycosides, tetracycline, sulfonamides, spectinomycin, chloramphenicol and nalidixic acid. by polymerase chain reaction and dna sequenci ...200616621462
gene expression profiling in salmonella choleraesuis-infected porcine lung using a long oligonucleotide microarray.understanding the transcriptional response to pathogenic bacterial infection within food animals is of fundamental and applied interest. to determine the transcriptional response to salmonella enterica serovar choleraesuis (sc) infection, a 13,297-oligonucleotide swine array was used to analyze rna from control, 24-h postinoculation (hpi), and 48-hpi porcine lung tissue from pigs infected with sc. in total, 57 genes showed differential expression (p < 0.001; false discovery rate = 12%). quantita ...200616845603
analysis of porcine differential gene expression following challenge with salmonella enterica serovar choleraesuis using suppression subtractive hybridization.swine-adapted salmonella enterica subsp. enterica serovar choleraesuis (s. choleraesuis) is the pathogen most frequently isolated from diseased pigs and may affect host gene expression in a species-specific manner. to characterize the porcine transcriptional response to s. choleraesuis infection, the mrna profiles from the mesenteric lymph nodes of three non-infected and three experimentally infected pigs at 24 h post-inoculation were analyzed by suppression subtractive hybridization (ssh). fort ...200616364571
mucosal innate immune response to intragastric infection by salmonella enterica serovar choleraesuis.the innate immune response is critical to enteric disease resistance and the induction of mucosal adaptive immunity. in mucosae of the small intestine, peyer's patches play a central role in immune surveillance and sampling of bacteria by specialized m cells. the innate immune response to salmonella enterica serovar choleraesuis, an enteric pathogen of swine, involves il-1beta and il-8 mrna induction but not that of il-6 and tnfalpha, in contrast to salmonella serovar typhimurium infection of mu ...200616325910
complete nucleotide sequence of pscv50, the virulence plasmid of salmonella enterica serovar choleraesuis sc-b67.we carried out comparative analysis on the sequences of two 50-kb virulence plasmids of salmonella enterica serovar choleraesuis strains sc-b67 (pscv50) and rf-1 (pkdsc50). the two plasmids share over 99% sequence similarity. ninety-two nucleotide variations at 42 sites were detected between the two plasmids; pscv50 contains 24 nucleotide substitutions, 6 deletions, and 62 insertions, compared to pkdsc50. two regions in pscv50 appeared to be more susceptible to changes: one is the non-virulence- ...200616257053
salmonella enterica serovar choleraesuis infection of the porcine jejunal peyer's patch rapidly induces il-1beta and il-8 expression.salmonella enterica serovar choleraesuis is an enteric pathogen of swine, producing septicemia, enterocolitis, pneumonia, and hepatitis. the initial molecular events at the site of salmonella infection are hypothesized to be critical in the initiation of innate and adaptive immune responses; however, the acute immune response elicited by porcine intestinal tissues is not well understood. to address this need, we employed explants of jejunal peyer's patch (jpp) mucosa from pigs to examine salmone ...200616115691
[cholangitis with hepatic microabscesses caused by salmonella enterica serovar choleraesuis].a 71-year-old man was admitted to the emergency unit of another hospital with a mild gastroenteritis and high fever. on admission g-gt and c-reactive protein (crp) levels were markedly elevated. under nonspecific antibiotic therapy with ampicillin/sulbactam the fever persisted and for the first time, on day 5, the patient complained of right-sided abdominal pain. an increase in the laboratory values indicated cholestasis. after changing the antibiotics to ceftriaxon and metronidazole, acute chol ...200717520506
analysis of porcine transcriptional response to salmonella enterica serovar choleraesuis suggests novel targets of nfkappab are activated in the mesenteric lymph node.specific knowledge of the molecular pathways controlling host-pathogen interactions can increase our understanding of immune response biology as well as provide targets for drug development and genetic improvement of disease resistance. toward this end, we have characterized the porcine transcriptional response to salmonella enterica serovar choleraesuis (s. choleraesuis), a salmonella serovar that predominately colonizes swine, yet can cause serious infections in human patients. affymetrix tech ...200818811943
subcutaneous vaccination with attenuated salmonella enterica serovar choleraesuis c500 expressing recombinant filamentous hemagglutinin and pertactin antigens protects mice against fatal infections with both s. enterica serovar choleraesuis and bordetella bronchiseptica.salmonella enterica serovar choleraesuis strain c500 is a live, attenuated vaccine that has been used in china for over 40 years to prevent piglet paratyphoid. we compared the protective efficacies of subcutaneous (s.c.) and oral vaccination of balb/c mice with c500 expressing the recombinant filamentous hemagglutinin type i domain and pertactin region 2 domain antigen (rf1p2) of bordetella bronchiseptica. protective efficacy against both s. enterica serovar choleraesuis infection in an oral fat ...200818268026
salmonella enterica serovar choleraesuis derivatives harbouring deletions in rpos and phop regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively.live attenuated salmonella enterica strains have been extensively studied as potential vectors for the oral delivery of heterologous antigens. due to its ability to target immune cells, its specific mechanism for crossing the intestinal barrier, and its swine-restricted tropism, s. enterica subspecies enterica serovar choleraesuis (s. choleraesuis) has attracted a great deal of interest for the production of bacterial-based oral carriers specifically adapted to swine. in this study, two mutants ...200818313237
humoral immune responses inhibit the antitumor activities mediated by salmonella enterica serovar choleraesuis.salmonella is a powerful antitumor agent owing to its tumor-targeting potential, antitumor capability, and ability to deliver therapeutic genes. host factors including innate and adaptive immune responses play roles in salmonella-induced antitumor activity. an emerging realization from animal models that host immune system responses to salmonella remains uncertain. herein, we used naive mice and salmonella enterica serovar choleraesuis (s. choleraesuis) immunized mice to study the role of humora ...200919342967
ferrous iron-binding protein omb of salmonella enterica serovar choleraesuis promotes resistance to hydrophobic antibiotics and contributes to its virulence.salmonella enterica serovar choleraesuis (sc) is an important enteric pathogen that causes serious systemic infections in swine and humans. to identify the genes required for resistance to antimicrobial peptides, we constructed a bank of sc transposon mutants and screened them for hypersensitivity to the cationic peptide polymyxin b. here we report one isolated polymyxin b-susceptible mutant that also exhibited increased sensitivity toward human neutrophil peptide alpha-defensin 1 (hnp-1) and hy ...200919389759
[characterization of attenuated salmonella c500 strain with a delta asd mutant and use as an asd+ balanced-lethal host-vector system].salmonella enterica serovar choleraesuis strain c500 is a live, attenuated vaccine that has been used in china for over 40 years to prevent piglet paratyphoid. the objective of this study was to evaluate the potential of attenuated salmonella enterica serovar choleraesuis c500 strain with a delta asd mutant as an effective live vaccine vector by the asd+ balanced-lethal host-vector system. here, we compared the characteristics of s. enterica serovar choleraesuis delta asdc500 strain with the par ...200919441223
mapping markers linked to porcine salmonellosis susceptibility.the goal of this study was to identify pig chromosomal regions associated with susceptibility to salmonellosis. genomic dna from pig reference populations with differences in susceptibility to salmonella enterica serovar choleraesuis as quantified by spleen and liver bacterial colonization at day 7 post-infection (dpi; van diemen et al. 2002) was used. these samples belonged to the offspring of a sire thought to be heterozygous for genes involved in susceptibility to salmonellosis. amplified fra ...200919496771
molecular characterisation of class 1 integrons in salmonella enterica serovar choleraesuis isolates from southern taiwan.integron-mediated multidrug resistance in salmonellaenterica serovar choleraesuis poses a major concern in human salmonellosis in taiwan. in this study, 71 strains of s. choleraesuis harbouring a class 1 integron from humans and animals were characterised for detection of integrons, gene cassettes and the spvc virulence gene using molecular genetic techniques. all 71 strains tested were negative for class 2 and 3 integrons. fifty-eight (81.7%) of the isolates harboured a class 1 integron with di ...200919084383
consumption of groundwater as an independent risk factor of salmonella choleraesuis infection: a case-control study in taiwan.infection with salmonella enterica serovar choleraesuis (s. choleraesuis) in humans can be considered as an endemic disease in certain regions of taiwan, and the number of cases has increased in recent years. the goal of the case-control study discussed in this article was to identify the possible demographic and environmental risk factors associated with s. choleraesuis infection in taiwan. during the period of december 2005 to march 2007, the case-control study was conducted in human patients ...200920063610
[construction and characterization of recombinant salmonella enterica serovar choleraesuis vaccine strain expressing heterologous antigen of pasteurella multocida toxin].this study was aimed to construct and characterize salmonella vaccine strain c500 expressing the recombinant pasteurella multocida toxin (pmt) antigen by the asd+ balanced-lethal host-vector system.201020344946
contribution of enhanced efflux to reduced susceptibility of salmonella enterica serovar choleraesuis to fluoroquinolone and other antimicrobials.we examined antimicrobial susceptibility and efflux systems in laboratory-derived mutants of salmonella enterica serovar choleraesuis selected by culture on fluoroquinolone-containing plates. the mutants exhibited decreased susceptibilities to quinolones and several other antimicrobials. mutations in the gyra gene were not always found in the mutants. accumulation assays revealed that intracellular enrofloxacin concentrations were significantly lower in the mutants compared with parent isolates. ...201020953129
use of inverse pcr for analysis of class 1 integrons carrying an unusual 3' conserved segment structure.by using inverse pcr and dna sequencing, 13 sul3-associated mutational integrons, 2 defective class 1 integrons, and 1 qnrb2-associated complex sul1-type class 1 integrons were identified in salmonella enterica serovar choleraesuis, pseudomonas aeruginosa, and enterobacter cloacae, respectively. in addition, conjugation and southern hybridization demonstrated that unusual class 1 integrons were located on plasmids or integrated into chromosomal dna. thus, an inverse pcr assay can be a valuable t ...201021098251
salmonella enterica serovar choleraesuis derivatives harbouring deletions in rpos and phop regulatory genes as vehicles for dna vaccines.we investigated the use of two previously described attenuated strains of salmonella enterica subspecies enterica serovar choleraesuis (s. choleraesuis), deltaphop and deltarpos, compared with the commercial attenuated sc-54 strain, as bactofection vehicles, to deliver an epitope model (3xflag) to the intestinal immune system. the gene encoding the epitope 3xflag was subcloned into the pcmvbetam2a mammalian expression vector (creating pcmv3xflagm2a) and introduced into s. choleraesuis strains. t ...201019720478
mutations in the salmonella enterica serovar choleraesuis camp-receptor protein gene lead to functional defects in the spi-1 type iii secretion system.salmonella enterica serovar choleraesuis (salmonella choleraesuis) causes a lethal systemic infection (salmonellosis) in swine. live attenuated salmonella choleraesuis vaccines are effective in preventing the disease, and isolates of salmonella choleraesuis with mutations in the camp-receptor protein (crp) gene (salmonella choleraesuis deltacrp) are the most widely used, although the basis of the attenuation remains unclear. the objective of this study was to determine if the attenuated phenotyp ...201019775595
comparison of salmonella serovar isolation and antimicrobial resistance patterns from porcine samples between 2003 and 2008.food-borne salmonella infections can produce symptoms from mild gastroenteritis to severe systemic disease and death, representing an important public health issue in u.s. livestock and livestock products, which have been implicated as frequent sources of salmonella contamination. concerns have been raised about the spread of antibiotic resistance in salmonella strains, particularly those that originate from food animal sources, as a result of prophylactic and therapeutic antimicrobial use in th ...201020622228
molecular typing and antimicrobial resistance of salmonella enterica subspecies enterica serovar choleraesuis isolates from diseased pigs in japan.salmonella enterica serovar choleraesuis (s. choleraesuis) isolates derived from diseased pigs in japan during 2001 and 2005 were analyzed for biotype, based on h(2)s production and dulcitol fermentation, pulsed-field gel electrophoresis (pfge) profile, and antimicrobial resistance profile. s. choleraesuis biotype choleraesuis (biotype choleraesuis) was classified into one genotype, while varietas kunzendorf (var. kunzendorf) was classified into two genotypes. the isolates of var. kunzendorf bel ...201018809209
molecular characterization of extended-spectrum cephalosporinase-producing salmonella enterica serovar choleraesuis isolates from patients in thailand and denmark.the objective of this study was to characterize extended-spectrum cephalosporinase (esc)-producing isolates of salmonella enterica serovar choleraesuis recovered from patients in thailand and denmark. twenty-four blood culture isolates from 22 patients were included in the study, of which 23 isolates were recovered from 21 thai patients during 2003, 2007, or 2008 and one isolate was recovered from a danish traveler to thailand. esc production was confirmed in 13 out of the 24 isolates by mic tes ...201020032253
t cell augments the antitumor activity of tumor-targeting salmonella.systemic administration of salmonella to tumor-bearing mice leads to preferential accumulation within tumor sites and retardation of tumor growth. however, the detailed mechanism of salmonella-induced antitumor immune response via host t cell remains uncertain. herein, we used wild-type, cd4(+) t-cell-deficient, and cd8(+) t-cell-deficient mice to study the role of t cell in the antitumor immune responses induced by salmonella enterica serovar choleraesuis (salmonella choleraesuis). when systemi ...201121360146
porcine toll-like receptors: recognition of salmonella enterica serovar choleraesuis and influence of polymorphisms.salmonella enterica serovar choleraesuis (sc) is a highly invasive pathogen that causes enteric and septicemic diseases in pigs. although there have been some reports on gene expression profiles in the course of infection with sc in pigs, little is known about the genes involved in the infection. by measuring activation, as represented by nuclear factor-+¦b activity, after stimulation by the pathogen, we showed the involvement of toll-like receptor (tlr) 5 and the tlr2-tlr1 heterodimer in the re ...201121388684
porcine circovirus type 2 potentiates morbidity of salmonella enterica serovar choleraesuis in cesarean-derived, colostrum-deprived pigs.problem addressed: porcine circovirus type 2 (pcv2) and salmonella enterica subspecies enterica serovar choleraesuis (s. choleraesuis) are two leading causes of economic loss in the swine industry. although s. choleraesuis infection occurs concurrently with pcv2-associated disease in many swine herds, the pathogenesis of concurrent infection with pcv2 and s. choleraesuis remains largely undefined. objective: we investigated the interactions between pcv2 and s. choleraesuis in 20 cesarean-derived ...201121782358
Reduction of Salmonella enterica serovar Choleraesuis carrying large virulence plasmids after the foot and mouth disease outbreak in swine in southern Taiwan, and their independent evolution in human and pig.BACKGROUND/PURPOSE: Salmonella enterica serovar Choleraesuis (S. Choleraesuis) is a highly invasive zoonotic pathogen that causes bacteremia in humans and pigs. The prevalence of S. Choleraesuis in man has gradually decreased since the outbreak of foot and mouth disease in pigs in 1997 in southern Taiwan. The goal of this study was to investigate the change in prevalence of S. Choleraesuis carrying the virulence plasmid (pSCV) in human and swine isolates collected in 1995-2005 and characterize t ...201122209685
natural lysogenization and transduction in salmonella enterica serovar choleraesuis by bacteriophage p1.it has been reported that bacteriophage p1 injects dna into serovar choleraesuis without evidence of productive infection. however, we found that p1 generates progeny and is capable of transduction in serovar choleraesuis. this is not the case with other serovars of salmonella enterica we tested. therefore, p1 could play a role in serovar choleraesuis evolution and contribute to its genetic manipulation and analysis.201222995628
dietary arginine supplementation alleviates immune challenge induced by salmonella enterica serovar choleraesuis bacterin potentially through the toll-like receptor 4-myeloid differentiation factor 88 signalling pathway in weaned piglets.the present study evaluated whether dietary arginine (arg) supplementation could attenuate immune challenge induced by salmonella enterica serovar choleraesuis c500 (s.c500) through the toll-like receptor (tlr) 4-myeloid differentiation factor 88 (myd88) signalling pathway in weaned piglets. a total of thirty-six weaned pigs were randomly allocated into six groups with six replicates per group. pigs were subjected to three dietary treatments (namely two groups per treatment) in the first week (0 ...201222214652
allele-specific primer polymerase chain reaction for a single nucleotide polymorphism (c1205t) of swine toll-like receptor 5 and comparison of the allelic frequency among several pig breeds in japan and the czech republic.in the present study, an allele-specific primer-polymerase chain reaction (asp-pcr) for genotyping a single nucleotide polymorphism (snp) of swine toll-like receptor 5 (tlr5) (c1205t; p402l) that is related to the impaired recognition of salmonella enterica serovar choleraesuis (sc) was developed. the allele frequencies in several pig breeds in japan and the czech republic were also compared. the swine tlr5 c1205t mutation was successfully determined by asp-pcr using genomic dna samples in japan ...201222420886
application of scutellariae radix, gardeniae fructus, and probiotics to prevent salmonella enterica serovar choleraesuis infection in swine.salmonella enterica serovar choleraesuis, a host-adapted pathogen of swine, usually causes septicemia. lactic acid bacteria (lab) strains have been widely studied in recent years for their probiotic properties. in this study, a mouse infection model first screened for potential agents against infection, then a pig infection model evaluated effects of lab strains and herbal plants against infection. scutellariae radix (sr) and gardeniae fructus (gf) showed abilities to reduce bacteria shedding an ...201323533497
decline in ciprofloxacin-resistant salmonella enterica serovar choleraesuis in taiwan, 2001-2011. 201323390070
a polymer coating applied to salmonella prevents the binding of salmonella-specific antibodies.the use of salmonella as a potential antitumor agent has been investigated, but innate immunity against this bacterium reduces the efficacy of its tumor-targeting and antitumor activities. the purpose of this study was to investigate the modulation of the tumor-targeting efficiency of salmonella enterica serovar choleraesuis by modifying the immune response to these bacteria by coating them with poly(allylamine hydrochloride) (pah), designated pah-s.c. to evaluate this modulation, we used naïve ...201322736433
porcine circovirus type 2 (pcv2) vaccination reduces pcv2 in a pcv2 and salmonella enterica serovar choleraesuis coinfection model.we previously reported that prior porcine circovirus type 2 (pcv2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of salmonella enterica serovar choleraesuis in infected pigs. here, we evaluated whether pcv2 vaccination is effective in reducing fecal shedding and tissue dissemination of s. choleraesuis and improving clinical signs associated with pcv2 and s. choleraesuis infection in 15 cesarean-derived, colostrum-deprived pigs ran ...201323107657
complete genome sequence of salmonella enterica serovar choleraesuis vaccine strain c500 attenuated by chemical mutation.salmonella enterica serovar choleraesuis strain c500 is a live vaccine attenuated by chemical methods. here, we report the complete genome sequence of the strain, which may be helpful for elucidating the attenuation mechanism of the vaccine strain.201425301657
evaluation of efficacy, biodistribution and safety of antibiotic-free plasmid encoding somatostatin genes delivered by attenuated salmonella enterica serovar choleraesuis.we describe here a balanced-lethal system using an asd(+) expression plasmid pvgs/2ss-asd encoding two copies of somatostatin (ss) genes carried by δasd/δcrp double mutant salmonella enterica serovar choleraesuis (named c501). the advantage of this novel system is the use of asd (aspartate-semialdehyde dehydrogenase) gene as selection marker to replace the antibiotic resistance markers, thus eliminating the industrial cultivation and environmental problems. we then evaluated the efficacy, biodis ...201424486312
mara and rama regulate virulence in salmonella enterica serovar choleraesuis.salmonella enterica serovar choleraesuis is considered as an important porcine pathogen that causes serious systemic infections and exhibits poor response to treatment because of an increase in multidrug resistance (mdr). among the various regulators of resistance, multiple antibiotic resistance factor a (mara) and regulator of acetate metabolism a (rama) are the most effective in conferring antibiotic tolerance by activation of multidrug efflux pumps. here we investigated the regulation of viru ...201526608721
antimicrobial resistance and molecular investigation of h2s-negative salmonella enterica subsp. enterica serovar choleraesuis isolates in china.salmonella enterica subsp. enterica serovar choleraesuis is a highly invasive pathogen of swine that frequently causes serious outbreaks, in particular in asia, and can also cause severe invasive disease in humans. in this study, 21 s. choleraesuis isolates, detected from 21 patients with diarrhea in china between 2010 and 2011, were found to include 19 h2s-negative s. choleraesuis isolates and two h2s-positive isolates. this is the first report of h2s-negative s. choleraesuis isolated from huma ...201526431037
live attenuated salmonella enterica serovar choleraesuis vaccine vector displaying regulated delayed attenuation and regulated delayed antigen synthesis to confer protection against streptococcus suis in mice.salmonella enterica serotype choleraesuis (s. choleraesuis) and streptococcus suis (s. suis) are important swine pathogens. development of a safe and effective attenuated s. choleraesuis vaccine vector would open a new window to prevent and control pig diseases. to achieve this goal, the mannose and arabinose regulated delayed attenuated systems (rdas), δpmi and δpcrp::tt arac pbadcrp, were introduced into the wild type s. choleraesuis strain c78-3. we also introduced δrela::arac pbadlaci tt to ...201526238722
a fatal case of iliopsoas abscess caused by salmonella enterica serovar choleraesuis that heterogeneously formed mucoid colonies.salmonella enterica subsp. enterica serovar choleraesuis, an organism highly adapted to swine, rarely causes invasive human infection. we describe a fatal case of salmonella ser. choleraesuis infection developing iliopsoas abscess. a part of organisms recovered from the blood formed mucoid colonies, which became reactive to anti-o antigen antisera after either heat treatment or subculture through semisolid agar.201525737074
reappearance of salmonella serovar choleraesuis var. kunzendorf in danish pig herds.salmonella enterica serovar choleraesuis is a porcine adapted serovar which may cause serious outbreaks in pigs. here we describe outbreaks of salmonellosis due to s. choleraesuis in four danish pig farms in 2012-2013 by clinic, serology, and microbiology and compare the isolates to those of a previous outbreak in 1999-2000. the infection was in some herds associated with high mortality and a moderate to high sero-prevalence was found. in 2012-2013 the disease contributed to increased mortality ...201525703158
multiplex pcr and microarray for detection of swine respiratory pathogens.porcine respiratory disease complex (prdc) is one of the most important health concerns for pig producers and can involve multiple viral and bacterial pathogens. no simple, single-reaction diagnostic test currently exists for the simultaneous detection of major pathogens commonly associated with prdc. furthermore, the detection of most of the bacterial pathogens implicated in prdc currently requires time-consuming culture-based methods that can take several days to obtain results. in this study, ...201526662640
tolc is important for bacterial survival and oxidative stress response in salmonella enterica serovar choleraesuis in an acidic environment.the outer membrane protein tolc, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in enterobacteriaceae. since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether tolc played a role in the acid tolerance of salmonella enterica serovar choleraesuis. comparison of the acid tolerance of the tolc mutant and the parental wild-type stra ...201627599929
novel antimicrobial peptides with promising activity against multidrug resistant salmonella enterica serovar choleraesuis and its stress response mechanism.to evaluate the antibacterial efficacy of novel antimicrobial peptides (amps) against multidrug-resistant (mdr) salmonella enterica serovar choleraesuis (salm. choleraesuis) and to delineate the amp-responsive mechanisms of wild-type (wt) and mdr strains.201627280957
engineering of a live salmonella enterica serovar choleraesuis negative-marker strain that allows serological differentiation between immunised and infected animals.the usefulness of salmonella vaccine vehicles is limited by the fact that control programmes relying on salmonella bacteriology and serology cannot differentiate infected animals from vaccinated ones, an ability referred to as diva (differentiating infected from vaccinated animals). as a first step towards salmonella-based diva vaccines, the ompa gene was deleted in live attenuated δphop and δrpos vaccine strains. the ompa gene is present in all salmonella enterica serovars and it encodes an abu ...201627240916
the non-fimbriate phenotype is predominant among salmonella enterica serovar choleraesuis from swine and those non-fimbriate strains possess distinct amino acid variations in fimh.although most salmonella serovars are able to infect a range of animal hosts, some have acquired the ability to cause systemic infections of specific hosts. for example, salmonella enterica serovar choleraesuis is primarily associated with systemic infection in swine. adherence to host epithelial cells is considered a prerequisite for initial infection, and fimbrial appendages on the outer membrane of the bacteria are implicated in this process. although type 1 fimbriae encoded by the fim gene c ...201626974320
hyperinvasiveness of salmonella enterica serovar choleraesuis linked to hyperexpression of type iii secretion systems in vitro.salmonella enterica serovars choleraesuis and typhimurium are among the non-typhoid salmonella serovars that are important zoonotic pathogens. in clinical observation, s. typhimurium typically causes diarrheal diseases; however, s. choleraesuis shows high predilection to cause bacteremia. the mechanism why s. choleraesuis is more invasive to humans remains unknown. in this study, we compared the s. typhimurium lt2 and s. choleraesuis sc-b67 proteomes through stable isotope labeling of amino acid ...201627886215
mucosal iga and ifn-γ(+) cd8 t cell immunity are important in the efficacy of live salmonella enteria serovar choleraesuis vaccines.salmonellosis, a disease caused by non-typhoidal salmonella strains which can be transmitted from swine to humans, is one of the leading public health problems around the world. paratyphoid of swine is controlled by vaccinating swine with salmonella enterica serovar choleraesuis (s. choleraesuis) live vaccine strain c500 in china. although the vaccine has good prophylactic efficacy, the mechanism of immunogenicity is unclear. using a c500-derived paratyphoid thermo-stable live vaccine (ptsl vacc ...201728406162
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