کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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3416978 | 1593736 | 2010 | 7 صفحه PDF | دانلود رایگان |
Streptococcus suis is an important swine and human pathogen, and also an emerging zoonotic agent. A surface-associated subtilisin-like serine protease (SspA) of S. suis was identified by screening a genomic expression library as fragments of this protein reacted most strongly with convalescent-phase pig sera. The sspA gene is present in 29 of 33 S. suis serotypes reference strains and is expressed on the surface of S. suis. Relative real-time quantitative PCR assay demonstrated that sspA mRNA expression in vivo was several thousand fold of that in vitro. A sspA− mutant was generated from a S. suis serotype 2 strain SC19 by allelic exchange. The mutant was not different from the wild type strain in subcellular structures and in hemolytic phenotype. However, the virulence of the sspA− mutant was markedly lower than the wild type in pigs as demonstrated in experimental infections. These data indicated that the surface-associated protein SspA is a conserved virulence factor of S. suis and is involved in the pathogenesis of S. suis.
Journal: Microbial Pathogenesis - Volume 48, Issues 3–4, March–April 2010, Pages 103–109