RESUMEN
To explore the molecular characteristics of Streptococcus suis serotype 2(ss2) isolated in Zhejiang province by deciding the variation loci and its variation frequency of Cps2J gene.The total DNA of 9 strains of ss2 isolated in Zhejiang province were extracted and amplifed by PCR. Then,the Cps2J fragments were cloned into plasmid carrier and completely sequenced after purification.Finally,the sequence results of all 9 ss2 isolates were compared with those obtained by other studies around the world.It was found that the open reading fragments of Cps2J in 9 SS2 isolates encoding 333 amino acids were 999 bp in length.Comparisons of this region among ss2 isolates revealed a similarity of between 98.8% and 99.9%, while the homology to ss1 strains varied between 56.8% and 57.0%.Our study shows the sequences of complete Cps2J segment are fairly stable and all these 9 ss2 strains of different sources possibly have the same evolutionary origin.