Study About Antigen Crossing, Antigenic Element And Superantigen Of Several Strains Of Enteropathogenic E. Colis From Swine

10 swine enteropathogenic E. colis were rejuvenescenced and 6 of them were selected to prepare blood serum. We had tested the reactance of cross agglutination and agar diffusion between the strains and the blood serums. No. 300 and No. 343 were selected because they had highly cross reaction. To test superantigen of No.300 and No.343, the antigens made by both of them immunized piglets, and then we detected the serum 0D values with indirect ELISA. The OMP(outer membrane protein) and PF(permeate factor) of No. 300 and No. 343 were extracted for SDS—PAGE and westen-blotting.The E. coli antigen serological test indicates that they have common antigenic element and the 0 antigen is more primary. The result of indirect ELISA suggested that the immunogenicity of mixed antigen of No. 300 and No. 343 outweighs separately No. 300 or No.343.The two strains has common antigen of the OMP which has good immunogenicity. The result of SDS—PAGE and westen-blotting indicated that two strains have good cross-reactivity . The OMP of them have 1 immunity strap which is 50KD.The PF is superantigen and it is secreted into liquid culture by E. coli. The PF of No. 300 and No. 343 were extracted and to be injected into rabbits. Result evids that it is venenous. The immunogenicity of antigen from liquid culture outweighs antigen from solid. The result of SDS — PAGE and westen-blotting indicate that the PF of No.300 and No.343 have 2 immunity straps which are separately 15KD and 20KD.The antigens of E. coli are multiple. The 0 antigen is the primary, the K antigen and H antigen are secondary than the 0 antigen, the OMP and PF areingredient of E. coli. Various E. coli possible have common antigenic element.