Dataset Information

Genetic analysis of capsular polysaccharide synthesis gene clusters from all serotypes of Streptococcus suis: potential mechanisms for generation of capsular variation.

ABSTRACT: Streptococcus suis strains are classified into 35 serotypes on the basis of the antigenicity of their capsular polysaccharides (CPs). CP synthesis genes are known to be clustered on the chromosome (cps gene cluster). The entire cps gene clusters of S. suis have so far been sequenced in 15 serotypes and found to be located between orfZ and aroA. In this study, to provide comprehensive information about S. suis CPs, we sequenced the entire cps gene clusters of the remaining serotypes and analyzed the complete set of S. suis cps gene clusters. Among the 35 cps gene clusters, 22 were located between orfZ and aroA, whereas the other 13 were flanked by other gene(s) on the chromosomes, and the chromosomal locus was classified into five patterns. By clustering analysis, the predicted products of cps genes found in the 35 serotypes were assigned into 291 homology groups, and all serotypes possessed a serotype-specific gene, except for serotypes 1, 2, 1/2, and 14. Because of the presence of genes encoding flippase (wzx) and polymerase (wzy), CPs of all serotypes were thought to be synthesized by the Wzx/Wzy pathway. Our data also implied the possibility of the transfer of the entire or partial cps gene clusters among S. suis strains, as well as the influence of spontaneous mutations in a single gene or a few genes on the antigenicity of some serotypes. Accumulation of these gene transfers and small-scale mutations may have generated the antigenic diversity of S. suis CPs.

SUBMITTER: Okura M

PROVIDER: S-EPMC3623174 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Genetic analysis of capsular polysaccharide synthesis gene clusters from all serotypes of Streptococcus suis: potential mechanisms for generation of capsular variation.

Okura Masatoshi M Takamatsu Daisuke D Maruyama Fumito F Nozawa Takashi T Nakagawa Ichiro I Osaki Makoto M Sekizaki Tsutomu T Gottschalk Marcelo M Kumagai Yumi Y Hamada Shigeyuki S

Applied and environmental microbiology 20130215 8

Streptococcus suis strains are classified into 35 serotypes on the basis of the antigenicity of their capsular polysaccharides (CPs). CP synthesis genes are known to be clustered on the chromosome (cps gene cluster). The entire cps gene clusters of S. suis have so far been sequenced in 15 serotypes and found to be located between orfZ and aroA. In this study, to provide comprehensive information about S. suis CPs, we sequenced the entire cps gene clusters of the remaining serotypes and analyzed ...[more]

PMID: 23416996

Similar Datasets

Project description:Streptococcus suis is an important porcine bacterial pathogen and a zoonotic agent responsible for sudden death, septic shock and meningitis, of which serotype 2 is the most widespread, with serotype 14 also causing infections in humans in South-East Asia. Knowledge of its pathogenesis and virulence are almost exclusively based on these two serotypes. Though serotype 9 is responsible for the greatest number of porcine cases in Spain, the Netherlands and Germany, very little information is currently available regarding this serotype. Of the different virulence factors, the capsular polysaccharide (CPS) is required for S. suis virulence as it promotes resistance to phagocytosis and killing and masks surface components responsible for host cell activation. However, these roles have been described for serotypes 2 and 14, whose CPSs are structurally and compositionally similar, both containing sialic acid. Consequently, we evaluated herein the interactions of serotype 9 with host cells and the role of its CPS, which greatly differs from those of serotypes 2 and 14. Results demonstrated that serotype 9 adhesion to but not invasion of respiratory epithelial cells was greater than that of serotypes 2 and 14. Furthermore serotype 9 was more internalized by macrophages but equally resistant to whole blood killing. Though recognition of serotypes 2, 9 and 14 by DCs required MyD88-dependent signaling, in vitro pro-inflammatory mediator production induced by serotype 9 was much lower. In vivo, however, serotype 9 causes an exacerbated inflammatory response, which combined with persistent bacterial presence, is probably responsible for host death during the systemic infection. Though presence of the serotype 9 CPS masks surface components less efficiently than those of serotypes 2 and 14, the serotype 9 CPS remains critical for virulence as it is required for survival in blood and development of clinical disease, and this regardless of its unique composition and structure.

Project description:Streptococcus suis is an important pathogen of pigs and may cause serious disease in humans. Serotyping is an important tool for detection and epidemiological studies of S. suis Thirty-three reference serotypes and nine novel cps loci (NCLs) are recognized in S. suis To gain a better understanding of the prevalence and genetic characteristics of NCLs, we investigated the serotype identity of 486 isolates isolated between 2013 and 2015 in China by capsular gene typing methods. Two hundred seventy-six isolates carried NCLs belonging to 16 groups, 8 of which appear to have not been reported previously. These isolates showed autoagglutination, polyagglutination, or nonagglutination with reference antisera and thus were nonserotypeable. Almost all isolates carrying the unknown NCLs were encapsulated, with various capsular thicknesses, indicating that they are most likely novel serotypes. To simultaneously identify the currently recognized 17 NCLs, an 18-plex detection system using the Luminex xTAG universal array technology was developed. Our data also provide valuable genetic information for monitoring the variations within NCLs by investigating the genetic characteristics of different subtypes within NCLs.ImportanceNonserotypeable Streptococcus suis isolates have been reported in many studies, and 9 novel cps loci (NCLs) have already been identified in nonserotypeable isolates. Moreover, novel cps loci are continually being found. The main purpose of this study was to investigate the prevalence and characteristics of NCLs in S. suis isolates recovered between 2013 and 2015 in China. This study provides valuable genetic information for monitoring the variations within NCLs. Meanwhile, a fast and cost-effective 18-plex detection system that can simultaneously identify the currently recognized 17 NCLs was developed in this study. This system will serve as a valuable tool for detecting known and identifying additional novel cps loci among nonserotypeable S. suis isolates.

Dataset Information

Genetic analysis of capsular polysaccharide synthesis gene clusters from all serotypes of Streptococcus suis: potential mechanisms for generation of capsular variation.

Publications

Genetic analysis of capsular polysaccharide synthesis gene clusters from all serotypes of Streptococcus suis: potential mechanisms for generation of capsular variation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets