ANTIBACTERIAL ACTIVITY OF MANGIFERA INDICA L. (MANGO) KERNEL ON CLARIAS GARIEPINUS (AFRICAN CATFISH) FINGERLINGS INFECTED WITH AEROMONAS CAVIAE

Résumé

Different approaches are employed to control diseases in fish with particular emphasis on the use of chemotherapeutic agents, however, application of chemicals in aquaculture is expensive and may lead to serious hazards in fish. This study was designed to evaluate the in vivo antibacterial activity of Mango kernel on Clarias gariepinus experimentally infected with Aeromonas caviae. A total of 240 fingerlings randomly divided into four groups of 60 each were used in the study. Fish in groups A, B, C and D were fed diet containing 0, 1, 5 and 10 g/kg of the kernel powder, respectively for 60 days. Sera were collected from 12 fish in each group after the first 20 and 40 days of feeding, and the antibacterial effect of the sera against A. caviae was assessed using Agar well diffusion method. Additional 12 fish from each group were challenged with A. caviae at 60 days post feeding, and clinical signs, mortalities and gross lesions were observed and recorded over 14 days post-infection.The sera of fish treated with mango kernel at different concentrations produced no antibacterial effect against A. caviae, however, less survivability was observed in fish fed control diet (50% survivability). Groups fed 5 and 10 g/kg mango kernel diet had the highest percentage survival (100%). The study showed that mango kernel protects C. gariepinus against A. caviae infection by enhancing the survivability of the treated fish. More studies to determine the actual dose of the kernel that gives the optimum fish survivability were recommended.