Antibiotic Susceptibility Profile of Gram-Negative Bacteria Isolated From Pond Catfish in Ketu Adie-Owe, Ado-Odo Local Government Area of Ogun State, Nigeria

The increasing number of fish ponds in Nigeria is driven by the demand for fish and fishery products. Catfish, specifically Clarias gariepinus, is popular for cultivation due to its economic significance. However, bacterial infections pose a threat to the health of catfish in these ponds, resulting in the need for antibiotic usage. This study is aimed to assess the antibiotic susceptibility pattern of Gram-negative bacteria isolated from pond catfish. This study involved isolating bacteria from the catfish skin and intestine, analyzing their biochemical characteristics, and conducting antimicrobial susceptibility testing. Fungi present in the catfish samples were also identified. The Gram-negative isolates were subjected to antibiotic susceptibility testing, revealing the prevalence of multidrug-resistant strains. The findings contribute to the understanding of antibiotic resistance in aquaculture and highlight the need for appropriate management strategies. The bacterial load in different catfish samples was examined through total plate counts and dilution effects. The results revealed variations in colony counts and CFU/ml values among the samples, with the highest bacterial load observed in the skin of large catfish. The bacterial load observed in the skin of catfish ranged from 4.7 X 103 CFU/ml to 9.8 X 103 CFU/ml, while the bacterial load observed in the intestine of catfish ranged from 3.1 X 103 CFU/ml to 5.4 X 103 CFU/ml. Biochemical testing identified specific organisms, including Enterobacter cloacae, Aeromonas hydrophila, Klebsiella pneumoniae, Citrobacter brakii, Citrobacter freundii, and Enterobacter aerogenes. Varying resistance patterns emphasize the need for careful antibiotic use and infection control in catfish aquaculture. Therefore, continuous monitoring and preventive measures are recommended.