Surface Display Of Aeromonas Hydrophila GAPDH In Attenuated Vibrio Anguillarum

Fish diseases have been the main problem of large-scale commercial fish farming in China. Vaccination plays an important role in the success of fish cultivation, instead of the use of vast amounts of antibiotics. Several new concepts for vaccine development have been proposed recently and one of these rational designs is the multivalent vaccine based on virulence-attenuated pathogens which can be used as carriers for surface-displaying heterologous protective antigens of other pathogenic microorganisms.In our previous work, two kinds efficient surface display systems have been established based on INP and lpp-ompA separately, which could successfully display GFP on the surface of attenuated Vibrio anguillarum.In this work, attenuated Vibrio anguillarum (MVAV6203) was used as a carrier, a putative protective antigen, the glyceraldehyde-3-phosphate dehydrogenase from pathogenic Aeromonas hydrophila LSA34, was fused to seven display systems and introduced into attenuated V. anguillarum strain MVAV6203 to get seven GAPDH-display strains. The strain AV/pN-gapA showed the best display efficacy of GAPDH, and was determined as the multivalent vaccine candidate. Further immune protection evaluation of AV/pN-gapA in turbot (Scophtalmus maximus) demonstrated that the attenuated V. anguillarum with surface-displayed GAPDH of A. hydrophila LSA34 effectively protected turbot from the infections of V. anguillarum (RPS=80%) and A. hydrophila (RPS=60%), which showed great potential value for further multivalent vaccine development.