Injection Vaccination of White-Spotted Char, Salvelinus leucomaenis, against Furunculosis with Aeromonas salmonicida Salmolysin

Abstract

Aeromonas salmonicida salmoysin was detoxified by heating at 37°C for 24 h, at 60°C for 30 min, at 100°C for 5 min, or heating at 37 or 60°C for 30 min with 0.4 % (v/v) formalin. These detoxified salmolysins and native salmolysin reacted with rabbit anti-native salmolysin serum. Juvenile white-spotted char (Salvelinus leucomaenis) were immunized two times at two-week intervals by intramuscular injection of salmolysin which was detoxified by heating at 60°C for 30 min. Mortalities of immunized and control fishes after challenge were 28.6 and 62.5 %, respectively. An antibody to salmolysin was detected in immunized fish sera, but not detected in control fish sera.These results indicate that detoxified salmolysin is an effective immunogen for the prevention of furunculosis in white-spotted char.