Detection of Streptococcus suis and their serotypes by PCR

202 swine tonsilla swabs collected from some areas in Guangdong province were detected for Streptococcus suis and their serotypes(1,2,7,9),using the PCR methods.147 S.suis strains were detected and the detection rate was 72.8%.Among of them,21 samples were S.suis serotype 2,6 samples were serotype 9,serotype 1 and 7 strains were not detected.The detection rate of S.suis and the serotypes were varied significantly among different areas and growth stages of pigs.The results showed that S.suis were existed widely in pigs,and multiple serotypes of S.suis seemed to be enzootic prevalence in Guangdong.