Evaluation of biofilm of Aeromonas hydrophila for oral vaccination of Clarias batrachus—a carnivore model

Biofilm of Aeromonas hydrophila was evaluated for oral vaccination of walking catfish (Clarias batrachus L.). Fish were fed with fish paste incorporating biofilm (BF) or free cells (FC) of A. hydrophila for 20 days and monitored for serum antibody production up to 60 days post-vaccination. Serum agglutinating antibody titre and relative percent survival (RPS) following challenge were found to be significantly higher in catfish fed with BF vaccine compared to that with FC.