Usage of propolis for treatment of rainbow trout (Oncorhynchus Mykiss) infected with Yersinia Ruckeri

In this study, rainbow trout (103.90 g mean weight in 86.3-124.2 g ranges) were infected with LD50 ve LD75 inoculates of Yersinia ruckeri. After 24 hours from infection, fish were treated with 2.5, 5 and 10 mg /kg doses of propolis for 21 days by using oral, injection and bath methods. Blood, liver, kidney, spleen and gills samples were taken in day 3., 4., 5., 9., 15. and 21. from all experimental fish. Nitroblue Tetrazolium (NBT), catalase activity, protein, total immunoglobuline, lipid peroxidation (MDA) and reduced glutation (GSH) levels were analyzed in these tissues and organs. At the same time, the mortality effect of propolis on fish was determined. In addition, fish organs were isolated for bacteriological inoculation during cure for examination in term of Yersinia ruckeri.Successful results in cure against Yersiniosis were obtained in fish infected with LD50 rate of bacteria after applying 2.5, 5 and 10 mg/kg fish doses of propolis given by food orally and injection intraperitoneally. In fish infected with LD75 rate of bacteria inoculates, success in cure was reached only in fish treated 10 mg/kg dose of propolis. In addition, cure efficiency in intraperitoneal method was found higher and quicker than that in oral method. Success was not obtained in cure by using bath method.Immunulogical parameters showed that NBT, protein and total immunoglobulin levels were reduced in infected fish, but these parameters were increased in fish treated with 2.5, 5 and 10 mg/kg fish ratio doses of propolis (p<0.05). It was found that MDA level which is a stress indicator increased during infection in blood, plasma and tissues of infected fish, GSH and catalase activity decreased. However stress decreased, GSH and catalase activity increased after treatment of infected fish with propolis (p<0.05).