Preparation Of Monoclonal Antibody Against Swine Streptococus Suis Serotype 2 And Establishment Of Immunoassay Method

The disease which is originated by Swine streptococcus suis 2 is a very important amphixenosis. It is very important to establish a kind of credible, sensitive and quick assaying method. In this experiment five isolates which were obtained from diseased pigs in Sichuan Province were identificated. The results showed five isolates were Streptococcus suis serotype 2.The BALB/C mice were immunized with the inactivated streptococcus suis type 2. Monoclonal antibody G5 and C10 were obtained using a purified capsular polysaccharide antigen-based indirect ELISA (CPS-ELISA). A double antibody sandwich ELISA was established to detect streptococcus suis type 2.In this experiment five isolates which were obtained from diseased pigs in Sichuan Province were identificated by morphosis, cultural characteristic, pathogenicity to animal ,biochemistry property and PCR method . The results showed five isolates were Streptococcus suis serotype 2, they have MRP and EF , S1,S2 and S5 were high pathogenicity, two were no pathogenicity.The BALB/C mice were immunized with the inactivated streptococcus suis type 2. When the serum antibody titre came to 1:16000. The BALB/C mice were immunized for 4 times. Streptococcus suis type 2 monoclonal antibodies were produced by conventional cell fusion technology. The spleen cells of immunized BALB/C mice were fused with SP2/0 cells using PEG and selected with HAT and HT medium. Tow hybridoma cell lines of G5 and C10 were obtained using a purified capsular polysaccharide antigen-based indirect ELISA (CPS-ELISA). G5 and C10 were cloned by limited dilution method for three times ,whose titers of ascites were 10×210 and 10×29. The subtype of them were both IgG1. SDS-PAGE showed that G5 and C10 all had two strips in about 45kDa and 15kDa respectively.Analysised by prohibitive ELISA, Streptococcus suis type 2 monoclonal antibodies showed good sensitivity. Both of them have no reaction with S. choleraesuis,App 1,App 9,E. coli etal , but have across response with isolates S1 and the specificity of G5 was better than C10. Immunoassay method were estabilshed with monoclonal antibody G5 by double sandwich ELISA and lay the foundation for the clinical detection and preparation of immunoassay diagnostic kit to Swine streptococcus suis type 2.