[Expression, purification and activity assay of Streptococcus suis serotype 2 cell wall protein SSU1664].

AIM

To amplify the SSU1664 gene from Streptococcus suis serotype 2 strain 05ZY, to express the gene in E.coli, and to evaluate the activities of the recombinant protein.

METHODS

SSU1664 gene was amplified by PCR using primers according to 05ZY genome sequences and cloned into the expression vector. The recombinant protein was purified by affinity chromatography and its immunogen activities were tested by Western blot and ELISA.

RESULTS

SSU1664 gene could solublely express in E.coli BL21(DE3). Western blot analysis showed that the recombinant protein could react with rat serum immunized with Streptococcus suis, but not with non-immunized rat serum. ELISA assay showed that anti-SSU1664 IgM content in Streptococcus suis-infected patient was significantly higher than that in healthy donors.

CONCLUSION

The recombinant SSU1664 protein has immunogen activity and might be one promising Streptococcus suis vaccine candidate and diagnosis marker of Streptococcus suis early infection.