| Streptococcus suis(SS) is an important pathogen of human and animal. Thirty-five capsular serotypes of S. suis have been described (types 1/2 and 1 through 34). Serotype 2(SS2) is considered to be the most-virulent serotype and prevalenced in wordwide. In China, SS2 was first isolated in 1991, later, human Streptococcus suis infection in Jiangsu province and Sichuan Province happened in 1998 and 2005, respectively.The distribution of virulence-associate factors of Europe Streptococcus suis isolates was reported. There were several genotypes and the strains of cps2/epf+/mrp+/sly+ were considered to be the most-virulent strains. The distribution of virulence-associate factors of China isolates was unknown. To investigate the distribution of virulence associate factors of Streptococcus suis (SS), 7virulence factors were selected to be detected by PCR assay, namely the glutamate dehydrogenase gene (gdh), the capsular polysaccharides gene (cps), the extracellular factor gene (epf), the muramidase-released protein gene (mrp), the suilysin gene (sly), the fibronectin-binding protein gene (fpbs) and the virulence-associated sequence orf2. 25 Chinese virulent SS2 isolates and 1 Chinese virulent SS7 isolate and 2 Chinese virulent SS9 isolates were detected in this assay. The positive detection rates of cps2/gdh+/epf+/mrp+/sly+/fbps+/orf2+ were 96% (24/25) and only one virulent SS2 isolate was cps2/gdh+/epf-/mrp+/sly+/fbps+/orf2+. 1 strain of SS7 was cps7/gdh+/epf—/mrp— /sly+/fbps—/orf2+, while, 2 strains of SS9 were cps9/gdh+/epf— /mrp—/sly—/fbps—/orf2+. The results showed the distribution of virulent associate factors of virulent streptococcus suis in China was different from isolates of Europe . The virulence associate factors profile was conform, which suggested that the prevalent strains of SS2 in China was virulent stains which have all 7 virulence factors.A multiplex PCR was developed for rapid and sensitive detection of virulent...
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