Occurrence and Antibiotic Sensitivity of Bacterial Strains Isolated from Nile Tilapia, Oreochromis niloticus Obtained in Ibadan, Southwest Nigeria

Abstract

The bacteriological quality of both wild and cultured Nile Tilapia, Oreochromis niloticus, sourced in some area of Ibadan, Southwest, Nigeria was studied. Bacteria flora of the skin and stomach of fish samples were examined and compared statistically (t-test independent). The resistance of bacterial isolates to commonly used antibiotics was also studied. Total aerobic bacteria count [colony forming unit: CFU = 159.50.13 ± 72, t Enterobacteriaceae count [(CFU) = 74.08 ± 5.55] with significant difference in the stomach were obtained in the Nile tilapia. The bacteria in the genera Staphylococcus, Escherichia, Proteus, Bacillus, Klebsiella, Micrococcus, Serratia, Pseudomonas, Salmonella and Streptococcus were isolated and had been proven to be of great public health significance. About 87.5% of the tested isolates were resistant to augmentin, 83.33% to cotrimoxazole and nalidixic acid. In addition, 79.17% of the isolates were resistant to tetracycline, 75.0% to amoxicillin, 54.17% to nitrofuratoin, 50.00% to ofloxacin and 29.17% to gentamicin. Among the eight antibiotics tested, six patterns of drug resistance were obtained and all of them were multiple drug resistance with three to eight. The public health implications of these observations are discussed.