Establishment of quadruple PCR for detecting subspecies and type 1,2 and 9 of swine streptococcus suis

According to the analysis of sequences,four pair primers were designed to amplified 725bp,212bp,387bp and 556bp fragments of four swine streptococcus suis genes including gdh,cps1I,cps2J and cps9G,respectively.At the same time,a quadruple PCR was established by adjusting reaction condition and system of four pairs of primers.The results showed that the aiming band of positive swine streptococcus suis was 725bp,and that of positive streptococcus suis type 1,2 and 9 were 725bp and 212bp,725bp and 387bp,725bp and 556bp,respectively.1059 isolated strains of streptococcus suis was detected by quadruple PCR,and it included 667 strains of positive streptococcus suis of swine,8 strains of streptococcus suis type 1,33 strains of type 2 and 16 strains of type 9,respectively.These results indicated that quadruple PCR detection was highly specific and sensitive,and could be applied on rapid diagnosis of disease of swine streptococcus suis and epidemiology research of streptococcus suis.