World Aquaculture Society Meetings


Ayofe M Hammed, Adekunle F Awe, Hakeem A Fashina-Bombata, Adebimpe O Olanloye and Nimah O Abdul-Gafar
 Department of Fisheries
 Faculty of Science
 Lagos State University
 P.O. Box 0001, LASU Post office, Ojo, Lagos,

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 (Azadirachta indica) while bacteria (Aeromonas hydrophila) was isolated from Clarias gariepinus. Twenty post juveniles Clarias gariepinus were infected with the isolated bacteria (A. 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 Aeromonas hydrophila. 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 A. hydrophila deviated to an abnormal range due to the inhibitory effects of the bacteria on the fish. After treatment with Neem leave extracts, significant differences were noticed at a concentrations of 50mg/l and 75mg/l when compared with the control group as the values rises to normal ranges.

The study was carried out with the purpose of determining the inhibitory activities of Aeromonas spp. on post juveniles' stage of catfish, Clarias gariepinus and to confirm the antibacterial activities of Azadirachta indica leaves extract on C. gariepinus infected with the bacteria. The result of the leaves extract on Clarias gariepinus  post juvenile at the four different concentrations (25, 50, 75, and 100mg) indicates that the leaves extract of Azadirachta indica is very active against Aeromonas spp on Clarias gariepinus post juvenile.

The study reveals that Aeromonas spp. is present in the body of Clarias gariepinus fish post juveniles and confirmed the inhibitory activities of the bacteria on Clarias gariepinus.

The result therefore emphasizes on the usefulness of Azadirachta indica leaves extract as an antibacterial agent on Clarias gariepinus post juveniles and the needs to enhance its exploitation, because it can be easily located in the different localities and markets across Nigeria and costs lesser than the other antibiotics used which may be scarce in some areas.

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