Strukturaufklärung des vi-antigens aus Citrobacter freundii (E. coli) 5396/38

Heyns, Kurt; Kiessling, G.

doi:10.1016/s0008-6215(00)82210-7

Cited by 93 publications

(47 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…GalNAcA (with variable 0 acetylation at the C-3 position) is found as a linear homopolymer in the Vi CPSs of Salmonella typhi, Salmonella paratyphi C, and Citrobacter freundii (10,16). Both QuiNAc and GalNAcA have been identified in 0-specific chains of LPS of P. aeruginosa strains (18,19,46).…”

Section: Resultsmentioning

confidence: 99%

Purification and determination of the structure of capsular polysaccharide of Vibrio vulnificus M06-24

et al. 1992

View full text Add to dashboard Cite

Virulence of Vtbrio vulnificus has been strongly associated with encapsulation and an opaque colony morphology. Capsular polysaccharide was purified from a whole-cell, phosphate-buffered saline-extracted preparation of the opaque, virulent phase of V. vulnificus M06-24 (M06-24/0) by dialysis, centrifugation, enzymatic digestion, and phenol-chloroform extraction. Nuclear magnetic resonance spectroscopic analysis of the purified polysaccharide showed that the polymer was composed of a repeating structure with four sugar residues per repeating subunit: three residues of 2-acetamido-2,6-dideoxyhexopyranose in the a-gluco configuration (QuiNAc) and an additional residue of 2-acetamido hexouronate in the a-galactopyranose configuration (GalNAcA). The complete carbohydrate structure of the polysaccharide was determined by heteronuclear nuclear magnetic resonance spectroscopy and by high-performance anion-exchange chromatography. The 'H and "3C nuclear magnetic resonance spectra were completely assigned, and vicinal coupling relationships were used to establish the stereochemistry of each sugar residue, its anomeric configuration, and the positions of the glycosidic linkages. The complete structure is:The polysaccharide was produced by a translucent phase variant of M06-24 (M06-24/T) but not by a translucent, acapsular transposon mutant (CVD752). Antibodies to the polysaccharide were demonstrable in serum from rabbits inoculated with M06-24/0.Vibio vulnificus is a halophilic bacterium that can cause severe wound infections or a syndrome of primary septicemia that is frequently fatal (mortality, >50%) in persons with underlying liver disease or hemochromatosis or who are immunocompromised (7,23,29). The organism is common in the estuarine environment (20,31). Wound infections are associated with seawater exposure, whereas primary septicemia apparently results from ingestion of V. vulnificus in raw oysters or other shellfish (29). In 1984, Kreger et al. (25) first described a major protective antigen of V. vulnificus that appeared, by electron microscopy, to be a ruthenium red-staining acidic polysaccharide layer or capsule located on the bacterial surface. The degree of encapsulation (estimated by electron microscopy) was subsequently correlated with colony morphology: encapsulated cells produced opaque colonies, whereas bacteria with a reduced ruthenium red-staining layer produced translucent colonies (36, 47). Opaque, encapsulated strains were found to shift to a translucent morphology at a rate of ca. 10-4 (36, 44, 47); shifts from translucent to opaque morphologies have been demonstrated at comparable frequencies (44). The opaque morphology has been correlated with increased virulence in mice, resistance to serum bactericidal activity, decreased hydrophobicity, and ability to utilize iron bound to saturated transferrin (36, 44). V. vulnificus produces a number of extracellular products that have been * Corresponding author. implicated as possible virulence factors, including cytolysin (15), elastolytic protease (24),...

show abstract

Section: Resultsmentioning

confidence: 99%

Purification and determination of the structure of capsular polysaccharide of Vibrio vulnificus M06-24

et al. 1992

View full text Add to dashboard Cite

show abstract

“…The tviABCDEvexABCDE operon (viaB locus) located on SPI7 contains genes involved in the regulation (tviA), the biosynthesis (tviBCDE) and the export (vexABCDE) of the Vi-capsular antigen (Virlogeux et al, 1995), a linear polymer of a-1,4 (2-deoxy)-2-Nacetylgalacturonic acid variably O-acetylated at the C3 position (Heyns and Kiessling, 1967). SPI7 is genetically unstable and can be lost upon laboratory passage of S. Typhi (Bueno et al, 2004;Nair et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

The Salmonella enterica serotype Typhi regulator TviA reduces interleukin-8 production in intestinal epithelial cells by repressing flagellin secretion

et al. 2007

View full text Add to dashboard Cite

“…This polysaccharide is a linear homopolymer of a-1,4 2-deoxy-2-N-acetylgalactosamine uronic acid variably O-acetylated at the C3 position (Heyns & Kiessling, 1967;Daniels et al, 1989). All strains of S. gpbi and Salmonella parat_yphi C, as well as a few strains of Salmonella dzlblin and Citrobacter frezmdii, are capable of expressing Vi antigen (Felix & Pitt, 1936;Baker et al, 1959;Le Minor & Nicolle, 1964).…”

Section: Introductionmentioning

confidence: 99%

Role of the viaB locus in synthesis, transport and expression of Salmonella typhi Vi antigen

et al. 1995

View full text Add to dashboard Cite

The Vi antigen is a capsular polysaccharide expressed by Salmonella typhi, the agent of human typhoid fever. Expression of this antigen is controlled by the viaA and viaB chromosomal loci. The viaB locus is composed of 11 genes designated tviA-tviE (typhi Vi), vexA-vex€ (Vi antigen export) and ORFl1. We constructed 5. typhi Ty2 strains carrying non-polar mutations in ten genes located at the viaB locus and examined the individual contribution of each gene to Vi phenotype. Phenotypes of the mutants and complementation experiments suggested that synthesis of Vi antigen monomer was catalysed by the TviB and TviC polypeptides. Subsequent polymerization of the polysaccharide might be catalysed by the TviE protein, but required functional TviD product. Proteins encoded by vexA, vexB and wexC directed transport of the polymer to the bacterial cell surface. Anchoring of the Vi antigen at the bacterial cell surface was dependent of the VexE protein. The TviA protein was not essential for Vi polymer synthesis. However, disruption of the tviA gene on 5. @phi Ty2 chromosome strongly decreased expression of Vi antigen. This defect was fully complemented by providing tviA in trans on a recombinant plasmid. By using lacZ transcriptional fusions, it was shown that the TviA product positively regulated co-transcription of the tviA and tviB genes from a promoter located upstream of tviA. Moreover, we showed that a tviAB-/acZ fusion was not expressed in a viaA (i'csB) mutant of S. typhi. However, expression of the tviAB-/acZfusion was restored in this wiaA mutant either by the rcsB gene of Escherichia coli, or by the tviA gene of 5. typhi when present in high copy number. This suggested that the tviA and wiaA products could be involved in the same regulatory pathway modulating Vi antigen expression in 5. typhi. Together these results demonstrated that proteins encoded by the viaB locus are not only involved in Vi polymer synthesis and translocation of the polysaccharide to the bacterial cell surface, but also in regulation of Vi antigen expression in 5. typhi.

show abstract

Strukturaufklärung des vi-antigens aus Citrobacter freundii (E. coli) 5396/38

Cited by 93 publications

References 12 publications

Purification and determination of the structure of capsular polysaccharide of Vibrio vulnificus M06-24

Purification and determination of the structure of capsular polysaccharide of Vibrio vulnificus M06-24

The Salmonella enterica serotype Typhi regulator TviA reduces interleukin-8 production in intestinal epithelial cells by repressing flagellin secretion

Role of the viaB locus in synthesis, transport and expression of Salmonella typhi Vi antigen

Contact Info

Product

Resources

About