| Streptococcus suis type 2 is an important pathogen of swine streptococcosis, which not only causes meningitis, arthritis, endocarditis, pneumonia, septicemia and sudden death in pigs, but also infects the employed persons and causes the death. It is also an important pathogen of zoonosis. To understand the carrier rate of Streptococ- cus suis type 2 in slaughtered pigs and to determine the distribution of virulence associated genes of Streptococcus suis type 2 isolated from slaughterd pigs in Fujian , this study was undertook to investigate the prevalence of Streptococcus suis type 2 in slaughtered pigs, to identify the isolated strains in morphology, biochemical characteristics and antibiotics resistance, and to determine and analysis the phenotype of the virulence factor of the isolated strains.121 nasopharyngeal swab samples of clinically healthy slaughtered pigs from 3 slaughter houses were collected. Prevalence of Streptococcus suis type 2 was investigated with PCR. The results showed that 17 positive samples were observed among 121 nasopharyngeal swab samples and the percentage was 14.0 % (17/121). The positive rate of Fuzhou area, Ningde area and Putian area was 10.9 %(7/64), 11.8 %(4/34) and 26.9 %(6/23) respectively. The results indicated that clincally healthy slaughtered pigs carried Streptococcus suis type 2 in several areas of Fujian and the positive rate was relatively high.5 strains of streptococcus were isolated from the 17 positive nasopharyngeal swab samples and the 50 palatine tonsils samples of slaughtered pigs.The correlated characters of the five strains were observed in morphology, biochemistry, antibiotics sensitivity,PCR assays based on specific cps2J gene and sequencing of PCR products. The results showed that the 5 strains were basically coincided with Streptococcus. The size of the PCR amplified products of the 5 isolates was 675 bp. Sequence analysis of the specific 675 bp DNA fragments cloned to T vector showed that the nucleotide homology with the sequences of Streptococcus suis type 2 published in Genebank was 98%-100%. The results suggested that all the isolates were Streptococ- cus suis type 2.To investigate the distribution of virulence associate factors of the 5 isolated strains of Streptococcus suis type 2 from slaughterd pigs and compare their virulence associate factors with the SS2PFJ07 from the diseased pig in Fujian, the 4 strains of Streptococcus suis type 2 from Nanjing Agricultural University and other domestic Streptococcus suis type 2 isolates, seven virulence genes were detected by PCR ampification. They were the glutamate dehydrogenase gene(gdh), the capsular polysaccharldes gene (cps), the extracellular factor gene (ef), the muramidate-released protein gene(mrp), the suilysin gene(sly), the fibronectin-binding protein gene(fbps) and the virulence-associated sequence orf2. Among the 5 isolated strains, the virulence genotype of Four strains was gdh+/cps2J+/mrp+/ef -/sly-/fbps+/orf2+and only one strain was gdh+/cps2J+/mrp+ /ef+/sly+/fbps+/orf2+. The virulence genotype of the SS2PFJ07 was gdh+ /cps2J+ /mrp+/ef -/sly-/fbps+/orf2+. The virulence genotype of four pathogenic strains of Streptococcus suis type 2 from Nanjing Agricultural University was gdh+/cps2J+/ mrp+/ef+/sly+/fbps+/orf2+. The results showed at least two virulence genotypes were detected in Streptococcus suis type 2 from slaughterd pigs in Fujian.The results of this study will provide epidemiological evidence of Streptococcus suis type 2 and provide scientific basis for monitor,prevention and control of Streptococcus suis type 2.
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