Application of oil adjuvanted vaccine against lactococcosis (Lactococcus garvieae) in rainbow trout (Oncorhynchus mykiss) in Italy

Objective: In recent years Lactococcosis caused by Lactococcus garvieae has been the principal bacterial disease affecting rainbow trout (Oncorhynchus mykiss) in Italy, especially during the fattening phases. L. garvieae is particularly virulent and can induce mortality rates of 30-50 % at the end of the productive cycle, in this way causing serious economic damage. Because antibiotic treatment has become less and less efficacious, vaccination is now the best approach to control the disease. Method & Materials: Formalin killed autovaccines (bacterin) was used in the past by trout farmers via i.p. injection, but the duration of protection was no longer then 3 months. Since 2004 to 2008, we produced more than 5 million doses of a new water in oil (W/O) adjuvanted autovaccine (1010 ufc/ml of bacterin with non mineral oil Montanide™ ISA 760 VG). This formulation was used by i.p. injection in 13 different trout farmings. Results & Conclusion: Mortality during vaccination was less than 0.5 %, while no outbreaks of Lactococcosis occurred and the cumulative mortality was less than 5 %. Side effects were limited and usually due to wrong vaccination procedures (soft anaesthesia, wrong needles, high number of fishes vaccinated per hour).

کلیدواژه ها:

Lactococcus garvieae ، autovaccine ، adjuvant ، intraperitoneum injection