A live attenuated strain of HY9901ΔdctP provides protection against Vibrio alginolyticus to the pearl gentian grouper (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatus)

In recent decades, vibriosis caused by Vibrio alginolyticus has become a severe threat to the global mariculture industry. There is an urgent need for effective vaccine alleviate this unoptimistic situation. study, we evaluated safety, immunoprotection, and specific non-specific immune response effect of Δ dctP strain as live-attenuated pearl gentian grouper (♀ Epinephelus fuscoguttatus × ♂ lanceolatu ). The results demonstrate that safe dose was ≤1.0 ×10 6 CFU in grouper. relative percent survival challenged with mutant intraperitoneal injection reached 74.4%, which significantly higher than control group. Meanwhile, expression level immune-relative genes, including IgM , IL-1β IL-8 IL-10 MHC-Iα MHC2 TNF-α TLR3 CD4 were upregulated liver, spleen, head kidney within 28 d post-vaccination. Moreover, antibody IgM, total serum protein well activities catalase, superoxide dismutase, lysozyme up-regulated vaccinated groupers compared those control. Collectively, could be used candidate against V. infection