Immunization of hybrid surubim (Pseudoplatystoma corruscans x P. fasciatum) against Motile Aeromonas hydrophila septicemia

ABSTRACT

The aim of this study was to evaluate the immune response of hybrid surubim vaccinated by intraperitoneal injection and by immersion against Aeromonas hydrophila. Vaccine was prepared with formalin-inactivated A. hydrophila. Forty eight fishes (47±9g) were distributed in 12 tanks (4 fish / tank) in the following treatments (4 tanks / treatment) unvaccinated fish, vaccinated intraperitoneally and vaccinated by immersion. After 21 days, intraperitoneally vaccinated fishes showed the highest values of total protein and immunoglobulins, agglutination titer and serum antimicrobial activity. Lysozyme concentration in the serum was higher in the fishes vaccinated by immersion than unvaccinated fishes. Intraperitoneal vaccination induced the highest immune response and could be used to improve the fish resistance against motile Aeromonas.