The comparative investigation on the immunological potency of vaccines produced from yersinia ruckeri serotype I and its field strains against enteric redmouth disease in rainbow trout

SUMMARYYersiniosis is one of the contagious diseases of all salmonid fish and known since1950?s. After the first isolation of the Yersinia ruckeri disease was reported fromseveral countries of America, Europe, Asia and Africa. The disease had diagnosed inTurkey at the end of the 1990 (Çağırgan ve Yüreklitürk, 1991). Since this firstisolation the infection has been found nearly all of the trout farm in Turkey.Vaccinations have been using to prevent ERM infection in many countries.Many methods were reported for ERM vaccination including administration routesof oral, injection, immersion, spray shower, anal intubation (Johnson ve Amend,1983).In this study five different vaccines were developed by using field and Denmarkisolates of Yersinia ruckeri and field isolates of enterococ. The experimentalvaccination was applied by orally, immersion and injection to a total of 1250rainbow trout weighed 6-10 g. Orally vaccinated fish were challenged at 70 day,immersion vaccinated fish were challenged at 28 and 75 days and injectionvaccinated fish were challenged at 45 and 105 days. Dead fish were taken daily andreisolations were tried from the kidneys. Potency of the vaccines were calculatedusing the formula, named relative percentage of survival.The results showed that field isolates provided more protection compared toDenmark isolates. Monovalan and polivalan vaccines provided similar protection.Relative percentage of survival values calculated based on mortalities, it has beendetermined that injection method provided the best protection compared to others.Enterococ vaccine (A3) provided relative protection between %72.7-100.