Studies Of Molecular Epidemiology Of Swine Streptococcus In Hunan Province

Streptococcus suis is one of the most important pathogen of swine in Hunan province.Studies on serotype and molecular epidemiology of Streptococcus from swine were investigated PCR typing.132 tonsils of slaughter pigs collectd in hunan province 2007,In these samples,57(43.2%) is positive for S.suis,S.equi subsp.zooepidemicus 13(9.9%).97 strains of Streptococcus were isolated from heart blood,lung,lymph node,brain and joint of swine from different areas in province, which were S.suis 24 strains(19.8%),S.equi subsp,zooepidemicus 28 strains (23.1%),SS2 4 strains(3.3%),SS9 2 strains(1.7%).Five virulence associate factors of Streptococcus suis 2 and cps of Streptococcus suis 9 were detected by PCR amplification,Through PCR sequencing and analysis of the nucleotide sequence.Sequence comparison and phylogenetic analysis revealed that the homogeny of CPS gene,MRP gene,EPF gene,SLY gene,ORF2 gene of Streptococcus suis 2 was respectively 97.9～100%,95.2～100%,99.6～100%,98.2～100%,92.9-100%.The sequence comparison and phylogenetic analysis showed that genes of four strains had closed genetic relationship with the isolates from Jiangsu,Sichuang in china and Netherlands, Japan,Spain.The result showed that SS2 in Hunan and the isolates from Jiangsu, Sichuang in china and Netherlands,Japan,Spain has common ancestor.Through sequence comparison and phylogentic analysis of the nucleotide revealed that the homogeny of cps gene of Streptococcus suis 9 was 98.3～99.6%, had close genetic relationship with the isolates from Jiangsu,Henan in china and Netherlands.The result showed that SS9 in Hunan and the isolates from Jiangsu, Henan in china and Netherlands has common ancestor,and Netherlands is the major prevalence country of SS9.