[Fusion of betal-toxin gene and beta2-toxin gene from Clostridium perfringens type C].

Betal-toxin and beta2-toxin genes from chromosomal DNA of Clostridium perfringens type C were amplified by PCR, PCR products were cleaved with restriction endonucleases and recovered. The recombinant plasmid pETXB1-2 containing beta1-beta2 fusion genes was constructed by recombinant technique and then transformed into Escherichia coli BL21 (DE3). The beta1-beta2 fusion proteins were expressed in recombinant strain BL21 (DE3) (pETXB1-2), and the expression level of the beta1-beta2 fusion proteins was about 15.36% of total cellular protein by SDS-PAGE and thin-layer gel scanning analysis. More importantly, immunization in a mouse model with crude preparation containing the fusion protein inclusion bodies or inactivated recombinant strain induced protection against at least 1 MLD of the toxin from Clostridium perfringens type C. Hence the fusion proteins possess a good immunogenicity. The constructed recombinant strain BL21 (DE3) (pETXB1-2) can be used as a candidate of vaccine strain.