Characterization of the Salmonella paratyphi C Vi polysaccharide

Daniels, Elaine; Schneerson, Rachel; Egan, William; Szu, Shousun C.; Robbins, John B.

doi:10.1128/iai.57.10.3159-3164.1989

Cited by 51 publications

(15 citation statements)

References 28 publications

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“…(v) Strains of S. typhi lacking Vi-antigen genes. In our sample of 334 isolates of S. typhi, 6 isolates of Tp 1 and 4 isolates of Tp 2 were phenotypically Vi negative. When probed for the viall region (53), four Tp 1 isolates and three Tp 2 isolates were positive, but DNA from the other two isolates of Tp 1 and from one isolate of Tp 2 failed to hybridize with the probe, thus demonstrating that a small proportion of S. typhi strains do not carry the Vi-antigen genes.…”

Section: Resultsmentioning

confidence: 60%

“…In the case of S. paratyphi C, we have demonstrated that the frequent failure of strains in laboratory culture to produce the Vi antigen is, with rare exception (1 of 35 phenotypically Vi-negative isolates probed), not attributable to an absence of the viaB gene region (61). Daniels et al (6) found that strains of S. paratyphi C rapidly lose Vi expression when passed on laboratory medium. In view of this finding and the observation that 67 of 78 isolates recovered in the course of an epidemic of enteric fever in South Africa and stored freeze-dried were Vi positive, Daniels et al (6) suggested that most strains of S. paratyphi C have Vi in the host.…”

Section: Discussionmentioning

confidence: 99%

“…Daniels et al (6) found that strains of S. paratyphi C rapidly lose Vi expression when passed on laboratory medium. In view of this finding and the observation that 67 of 78 isolates recovered in the course of an epidemic of enteric fever in South Africa and stored freeze-dried were Vi positive, Daniels et al (6) suggested that most strains of S. paratyphi C have Vi in the host.…”

Section: Discussionmentioning

confidence: 99%

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Evolutionary genetic relationships of clones of Salmonella serovars that cause human typhoid and other enteric fevers

et al. 1990

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Multilocus enzyme electrophoresis was employed to measure chromosomal genotypic diversity and evolutionary relationships among 761 isolates of the serovars Salmonella typhi, S. paratyphi A, S. paratyphi B, S. paratyphi C, and S. sendai, which are human-adapted agents of enteric fever, and S. miami and S. java, which are serotypically similar to S. sendai and S. paratyphi B, respectively, but cause gastroenteritis in both humans and animals. To determine the phylogenetic positions of the clones of these forms within the context of the salmonellae of subspecies I, comparative data for 22 other common serovars were utilized. Except for S. paratyphi A and S. sendai, the analysis revealed no close phylogenetic relationships among clones of different human-adapted serovars, which implies convergence in host adaptation and virulence factors. Clones of S. miami are not allied with those of S. sendai or S. paratyphi A, being, instead, closely related to strains of S. panama. Clones of S. paratyphi B and S. java belong to a large phylogenetic complex that includes clones of S. typhimurium, S. heidelberg, S. saintpaul, and S. muenchen. Most strains of S. paratyphi B belong to a globally distributed clone that is highly polymorphic in biotype, bacteriophage type, and several other characters, whereas strains of S. java represent seven diverse lineages. The flagellar monophasic forms of S. java are genotypically more similar to clones of S. typhimurium than to other clones of S. java or S. paratyphi B. Clones of S. paratyphi C are related to those of S. choleraesuis. DNA probing with a segment of the viaB region specific for the Vi capsular antigen genes indicated that the frequent failure of isolates of S. paratyphi C to express Vi antigen is almost entirely attributable to regulatory processes rather than to an absence of the structural determinant genes themselves. Two clones of S. typhisuis are related to those of S. choleraesuis and S. paratyphi C, but a third clone is not. Although the clones of S. decatur and S. choleraesuis are serologically and biochemically similar, they are genotypically very distinct. Two clones of S. typhi were distinguished, one globally distributed and another apparently confined to Africa; both clones are distantly related to those of all other serovars studied.

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Section: Resultsmentioning

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Evolutionary genetic relationships of clones of Salmonella serovars that cause human typhoid and other enteric fevers

et al. 1990

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“…These data showed that expression of the Vi-antigen blocked O-antigen agglutination in both S. Typhi and S. Typhimurium. It is relevant to mention in this context, that although the viaB locus is present in S. enterica serotype Paratyphi C, expression of the Vi-antigen does not interfere with O-antigen agglutination in this serotype (Daniels et al, 1989).…”

Section: Expression Of the Vi-capsule In S Typhimurium Prevents O-anmentioning

confidence: 99%

The Vi-capsule prevents Toll-like receptor 4 recognition of Salmonella

et al. 2008

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SummaryThe viaB locus enables Salmonella enterica serotype Typhi to reduce Toll-like receptor (TLR) dependent cytokine production in tissue culture models. This DNA region contains genes involved in the regulation (tviA), biosynthesis (tviBCDE) and export (vexABCDE) of the Vi capsule. Expression of the Vi capsule in S. Typhimurium, but not expression of the TviA regulatory protein, reduced tumour necrosis factor-alpha (TNF-a) and IL-6 production by murine bone-marrow derived macrophages. Production of TNF-a and IL-6 was dependent on expression of TLR4 as stimulation of macrophages from TLR4 -/-mice with S. Typhimurium did not result in expression of these cytokines. Intraperitoneal infection of mice with S. Typhimurium induced expression of TNF-a and inducible nitric oxide synthase (iNOS) in the liver. Introduction of the cloned viaB region into S. Typhimurium reduced TNF-a and iNOS expression to levels observed after infection with a S. Typhimurium msbB mutant. In contrast, no differences in TNF-a expression between the S. Typhimurium wild type and strains expressing the Vi-capsule or carrying a mutation in msbB were observed after infection of TLR4 -/-mice. We conclude that the Vi capsule prevents both in vitro and in vivo recognition of S. Typhimurium lipopolysaccharide by TLR4.

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“…Salmonella Paratyphi A and B do not produce Vi polysaccharide. S. Paratyphi C, expresses Vi, but it is a very rare cause of enteric fever [53] [27]. These findings are intriguing, although information about serotypes other than S. Typhi are quite limited and require larger studies targeted toward these serotypes to draw conclusions.…”

Section: Discussionmentioning

confidence: 99%

Salmonella entericaserovar Typhi and gallbladder cancer: a case–control study and meta‐analysis

et al. 2016

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In Chile, where gallbladder cancer (GBC) rates are high and typhoid fever was endemic until the 1990s, we evaluated the association between Salmonella enterica serovar Typhi (S. Typhi) antibodies and GBC. We tested 39 GBC cases, 40 gallstone controls, and 39 population‐based controls for S. Typhi Vi antibodies and performed culture and quantitative polymerase chain reaction for the subset with bile, gallstone, tissue, and stool samples available. We calculated gender and education‐adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association with GBC. We also conducted a meta‐analysis of >1000 GBC cases by combining our results with previous studies. GBC cases were more likely to have high Vi antibody titer levels than combined controls (OR: 4.0, 95% CI: 0.9–18.3), although S. Typhi was not recovered from bile, gallstone, tissue, or stool samples. In our meta‐analysis, the summary relative risk was 4.6 (95% CI: 3.1–6.8, P heterogeneity=0.6) for anti‐Vi and 5.0 (95% CI: 2.7–9.3, P heterogeneity = 0.2) for bile or stool culture. Our results are consistent with the meta‐analysis. Despite differences in study methods (e.g., S. Typhi detection assay), most studies found a positive association between S. Typhi and GBC. However, the mechanism underlying this association requires further investigation

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Characterization of the Salmonella paratyphi C Vi polysaccharide

Cited by 51 publications

References 28 publications

Evolutionary genetic relationships of clones of Salmonella serovars that cause human typhoid and other enteric fevers

Evolutionary genetic relationships of clones of Salmonella serovars that cause human typhoid and other enteric fevers

The Vi-capsule prevents Toll-like receptor 4 recognition of Salmonella

Salmonella entericaserovar Typhi and gallbladder cancer: a case–control study and meta‐analysis

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