Identification And Application Of A Novel Genetic Marker Of Vibrio Harveyi

Vibiro harveyi is an important pathogenic bacterium in aquaculture,so its immune protection is of significance.In this study,a novel gene was identified, which encodes a protein of unknown function and is only found in Vibiro harveyi isolates..A vhhP2-based PCR method was developed,which can be used in the quick detection of V.harveyi from animal blood,tissues,and environmental samples. Vaccination studies showed that VhhP2 was immunoprotective as a subunit vaccine. Using surface display technology,a live bacterial vaccine was developed,which displayed VhhP2 on the surface of a fish commensal strain.Japanese flounder immtmized with this live bacterial vaccine showed significantly higher resistance against V.harveyi infection.VhhP2 was also used as a carrier for the surface display of an Edwardsiella tarda antigen,and the resulting chimeric vaccine showed cross protection against V.harveyi and E.tarda infection.