Antibiotic Susceptibility Test (Tetracycline and Amoxicillin) against intestinal bacteria isolated from cultured African catfish (Clarias gariepinus) in Katsina Metropolis, Nigeria

Abstract

The increasing prevalence of antibiotic-resistant bacteria in aquaculture systems has become a major concern due to its implications for fish health, ecological sustainability, and public health. This study examined the intestinal bacteria of cultured African catfish (Clarias gariepinus) and evaluated the isolates' susceptibility to tetracycline and amoxicillin. A total of nine (9) fish samples were randomly obtained from three (3) fish farms within Katsina metropolis, Nigeria. Intestinal contents of the fish were aseptically collected, and the bacterial isolates observed were identified using colony morphology, Gram staining, and standard biochemical tests. Antibiotic susceptibility testing was conducted using the Kirby–Bauer disk diffusion technique in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Eleven (11) bacterial isolates were identified, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, and Proteus mirabilis. A significant number of the isolates exhibited resistance to amoxicillin, whereas higher levels of susceptibility were observed for tetracycline.

Keywords: Clarias gariepinus, intestinal bacteria, antibiotic resistance, tetracycline, amoxicillin, aquaculture