Construction of an engineered bivalent vaccine strain consisting of Vibrio cholerae CT-B and LPS-O antigens

Abstract

In this study, the engineered E. coli strain 1046 containing V. cholerae LPS-O and CTB bivalent antigen genes has been successfully obtained by using DNA recombinant techniques. E. coli 1046 (pMG305) could not only express CT-B antigen but also secret CTB into medium as shown by GM1-ELISA. Meanwhile, whole cell O-antigen-ELISA, bacterial agglutination test and hemagglutination inhibition assay demonstrated that LPS-O antigen could be expressed on the cell surface by E. coli 1046 (pMG305) and shown LPS band specific for V. cholerae by SDS-PAGE assay. Mouse intraperitoneal immunization and challenge trial indicated that the E. coli 1046 (pMG305) provided good protection against virulent V. cholerae. The engineered vaccine strain reported here is expected to be a live oral candidate vaccine for V. cholerae.