Cloning, expression of V ibrio alginolyticus outer membrane protein‐ O mp U gene and its potential application as vaccine in c rimson snapper, L utjanus erythropterus B loch

The outer membrane proteins of the marine aquatic animal pathogen, V ibrio alginolyticus , play an important role in the virulence of the bacterium and are potential candidates for vaccine development. In this study, the gene encoding an outer membrane protein‐ O mp U was cloned and expressed in E scherichia coli . Polyclonal antibodies were raised in rabbits against the purified recombinant O mp U , and the reaction of the antibody was confirmed by Western blotting using the isolated O mp U and the recombinant O mp U of V . alginolyticus . To analyze the immunogenicity of the recombinant O mp U , c rimson snapper, L utjanus erythropterus B loch, were immunized by intraperitoneal injection, and antibody response was assessed by the enzyme‐linked immunosorbent assay ( ELISA ). The results demonstrated that the recombinant O mp U produced an observable antibody response in all sera of the vaccinated fish. The vaccinated fish were challenged by virulent V . alginolyticus and observed to have high resistance to infection. These results indicate that the recombinant O mp U is an effective vaccine candidate against V . alginolyticus in L . erythropterus .