IMMUNOGENICITY OF AMEBIC ANTIGENS IN RAINBOW-TROUT, ONCORHYNCHUS-MYKISS (WALBAUM)

Rainbow trout developed a humoral immune response against numerous antigens of sonicated amoebae which were emulsified with Freund's complete adjuvant and injected into the peritoneum. The amoebae were cultured from the gills of Atlantic salmon, Salmo salar L., affected by amoebic gill disease. Antibodies in fish sera were detected by both enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Non-specific reactivity in fish serum against Escherichia coli, the bacterium used in co-cultivation of amoebae in vitro, was removed by immunoadsorption. Results obtained using ELISA and immunoblotting were comparable and indicated no significant difference in response to immunization with 10, 50 or 250 mug of sonicated amoebic protein. Amoebae contained immunogenic components of > 100, 100, 89, 49, 37 and 34kDa.