Development And Immune Effect On Five-valent Adjuvant Vaccine Of Important Bacterial Diseases Of Scophthalmus Maximus

As frequent diseases and antibiotics abuse becomes more and more serious , heavy losses were caused in turbot industry.So there is an urgent need to develop a polyvalent vaccine ,which can prevent and control variety of diseases simultaneously. Vibrio anguillarum, Vibrio scophtalmi, Ewardsiela tarda, Vibrio harveyi, Vibrio alginolyticus are the most lethal pathogenic bacteria to turbot,and in this paper the five pathogenic bacteria were researched.They were firstly cultured in liquid and then manufactured five-valent vaccine by formalin inactivated .One part of five-valent vaccine was mixed with astragalan, propolis and FCA respectively(1:1), and then were injected to turbot via intraperitoneal. Antibody titer, activities of lysozyme and superoxide dismutase were examined on 7th, 14th, 21th, 28th, 35th,42th and 56thd after first vaccination. Finally, all the fish were challenged with five kinds of bacteria (mentioned above) on 56 d. The results showed that the activities of lysozyme , superoxide dismutase and antibody titer went up firstly and then declined, which reached the peak value on 28 d.The immune enhancement of FCA group was significantly higher than that in Astragalan group and in Propolis group, and the synergy of Astragalan group was similar with Propolis group , but both Astragalan group and Propolis group were obviously higher than no-adjuvant group. The RPS of FCA group were 70.0% , 87.5%, 85.7%, 75.0%,77.8% respectively, 50.0%,62.5%,71.4%,50.0%,44.4% in Astragalan group, 50.0%, 62.5%, 57.1%,50.0%,55.6% in Propolis group, and 30.0%,50.0%,42.9%,37.5%,44.4% in no-adjuvant group.The other part of five-valent vaccine was mixed with astragalan and propolis respectively(1:2 and 2:1), and they were called Astragalan group 1, Propolis group 1, Astragalan group 2,and Propolis group 1.Similarly antibody titer, activities of lysozyme and superoxide dismutase were examined on 7th,14th,21th,28th,35th,42th,56thd after first vaccination. Finally, all the fish were challenged with five kinds of bacteria(mentioned above) on 56 d.The result revealed that activity of lysozyme in Astragalan group 1and Propolis group 1only significantly higher than that in no-adjuvant group(P<0.05), but the activity of SOD was always no different with no-adjuvant group.Meanwhile, the antibody titer to the five bacteria was overall under no-adjuvant group respectively.Expect the RPS of Vibrio alginolyticus in Astragalan group 1 and the RPS of Vibrio scophtalmi in Propolis group 1 was equal to that in no-adjuvant but the RPS of the other bacteria in no-adjuvant was all higher than that in Astragalan group 1 and Propolis group 1.Moreover, the immune effects in no-adjuvant were all higher than that in Astragalan group 2 and Propolis group 2.The results mentioned above revealed that the five-valent vaccine could enhance the immunity in turbot. In addition, the immune enhancement was improved to the highest in FCA group. Astragalan-adjuvant and propolis–adjuvant took the second place.Besides, the immune effects were the best when five-valent vaccine was mixed with astragalan and propolis respectively(1:1) .