Rumbidzai Mangoyi, Washington Mafukidze, Kerstin Marobela and Stanley Mukanganyama
Aeromonas hydrophila is one of the serious pathogens in ornamental fishes causing hemorrhagic bacterial
septicemia leading to inflammation and necrosis of the gastrointestinal tract, kidney, muscle, and spleen. Recent studies demonstrated that immunoproteomic vaccines provide protection against bacterial pathogens in fin fish aquaculture and the vaccines are popular due to its long lasting immunity, safety and low cost versatile characteristics. In this study we used an Outer Membrane Protein (OMP) of Aeromonas hydrophila as a vaccine to provide protection against the pathogen in goldfish (Carassius auratus). We used the extract of Asparagus racemosus as an adjuvant in the vaccine preparation. Surivival and immunological response of the vaccinated fishes (30 and 60 days post vaccination (dpv)), were evaluated after challenge with virulent A. hydrophila. The vaccine treated experimental groups significantly improved (P<0.05) the survival at 50% compared to the controls and had improved immunological responses including phagocytosis, albumin-globulin ratio, serum bactericidal activity, and serum lysozyme activity.