Improving a vaccine against Renibacterium salmoninarum in rainbow trout (Onchorhynchus mykiss)

In this study, it was aimed to develop a DNA vaccine against Renibacterium salmoninarumwhich causes bacterial kidney disease (BKD) in rainbow trout (Onchorhynchus mykiss). 40 Fish per tank were stocked into 9 tanks (100 L each). MSA1 and P22 genes were cloned and injected to fish intraperitoneally with the rate of 150ng/µl/fish.On the 7th and 30th days of the study, blood and tissue samples were taken from the fish and the changes in the immune parameters were examined. Additionally, at the end of the 30th day, the fish were subjected to challenge test with R. salmoninarum pathogen and their survival rates were determined for the following 21 days. At the end of the experiment, when the immunological responses were examined, MSA1 and P22 gene expressions were enhanced (P<0.05) in comparison with control group according to results of IL-1β, IL-8, IL-10, IL-12, IL-6, COX2, TGF-β, IgM, iNOS and MHC2 gene expressions. On the other hand, ORP and MPO activities were increased on the 7th and 30th days of the study compared to control group. No change in LYS activities was observed. Although there was no change in the survival rates of the fish vaccinated with two different DNA-based vaccines, P22 and MSA1 gene expressions were increased particullary in spleen and intestine, showing immunostimulating effect of the current application.