Antibacterial activities of Neemleave (Azadirachtaindica) extracts on African mud catfish Clarias gariepinus (Burchell, 1822)

Large-scale settings of aquaculture have resulted in an increased antibiotic resistance in bacteria potentially pathogenic to fish. Hot water method was used in extracting the Neem leaves (Azadirachtaindica) and bacteria were isolated from Clarias gariepinus. Twenty post juveniles Clarias gariepinus were infected with the isolated bacteria (Aeromonas hydrophila) and assessed at different concentrations of 25mg/l, 50mg/l, 75mg/l, and 100mg/l to confirm the inhibitory effects of the species and later treated with leave extracts to determine the antibacterial activities. The result shows bactericidal effects of the leave extracts against the Aeromonashydrophila. All the haematological indices i.e. Packed Cell Volume (PCV), Red blood cell count (RBC), White Blood Cell (WBC), Haemoglobin (Hb), Mean Corpuscular Haemoglobin Concentration (MCHC) and Mean Corpuscular Volume (MCV) of fishes inoculated with Aeromonas hydrophila deviated to an abnormal range due to the inhibitory effects of the bacteria on the fishes. After treatment with Neem leave extracts, significant differences were noticed at a concentrations of 50mg/l and 75mg/l when compared to the control group as the values rises to the normal ranges. This implies that the antibacterial activities of the Azadirachta indica leaves extract is concentration dependent and one can therefore say that Azadirachtaindica leaves extract is very active in treating Aeromonashydrophila.