The major pneumococcal virulence determinant is its capsule, and pneumococcal epidemiology is based on 91 capsular serotypes, each corresponding to the structure of the capsular polysaccharide determined by the type-specific capsular genome. Here, we provide the beginnings of an approach to intertwine serotype epidemiology, capsular regulatory gene characteristics on the basis of existing seque...

Serum anticapsular polysaccharide antibodies confer immunity to invasive diseases caused by Haemophdus influenzae type b (HIB) t (1-10). These anti-type b antibodies exert their protective effect by initiating complement-mediated activities including opsonization and bacterial lysis (2-5, 11). A protective level of ~0.15 #g of anti-type b antibodies/ml serum was estimated based upon analyses of...

Current serotyping methods classify Pasteurella multocida into five capsular serogroups (serogroups A, B, D, E, and F) and 16 somatic serotypes (serotypes 1 to 16). In the present study, we have developed a multiplex PCR assay as a rapid alternative to the conventional capsular serotyping system. The serogroup-specific primers used in this assay were designed following identification, sequence ...

We here report the first total synthesis of Streptococcus pneumoniae serotype 1 (Sp1) oligosaccharide, a unique zwitterionic capsular polysaccharide carrying labile O-acetyl esters. The target oligosaccharides, featuring rare a-2,4-diamino-2,4,6-trideoxy galactose (AAT) and a-galacturonic acids, were assembled up to 9-mer level, in highly stereoselective manner using trisaccharide building bloc...

The polysaccharide capsule is a major antigenic factor in Streptococcus agalactiae (Lancefield group B streptococcus [GBS]). Previous observations suggest that exchange of capsular loci is likely to occur rather frequently in GBS, even though GBS is not known to be naturally transformable. We sought to identify and characterize putative capsular switching events, by means of a combination of ph...

The type III polysaccharide of -roup B Streptococcus has been isolated and purified by a method that employs washing of intact cells at neutral pH. That the polysaccharide prepared by this procedure is the "native" type III antigen is suggested by its molecular size in excess of 10(6) daltons, its degradation by acid and heat treatment to a fragment with immunologic characteristics of the class...

We describe here isolation of genetically atypical serotype 6 Actinobacillus pleuropneumoniae in Japan indistinguishable by the multiplex PCR that can discriminate between immunologically cross-reactive serotypes 3, 6 and 8. Nucleotide sequence analysis of capsular export and biosynthesis genes revealed that the atypical isolates have capsular polysaccharide export and synthesis gene sequences ...

The complete nucleotide sequence of the capsular gene cluster (cap8) responsible for the biosynthesis of the capsular polysaccharide of Streptococcus pneumoniae type 8 has been determined. The cap8 gene cluster, located between the genes dexB and aliA, is composed of 12 open reading frames. A 14.7-kb DNA fragment embracing the cap8 genes was sufficient to transform an unencapsulated type 3 S. p...