Antibiogram of aerobic bacteria isolated from skin lesions of African catfish cultured in Southeast, Nigeria

Abstract

Aerobic bacteria associated with skin lesions in African catfish cultured in Southeast, Nigeria has not been documented. This study was conducted to identify aerobic bacteria associated with skin lesions of African catfish reared in Southeast Nigeria and to determine the antibiogram of the bacterial isolates. Scrapings from skin lesions of 129 fish from 27 fish ponds in 3 states in Southeast Nigeria were processed for aerobic bacteria isolation and identification following standard methods. Phenotypic resistance of the bacterial isolates to antimicrobial agents was conducted using the disc diffusion method. Skin lesions from 55(67%) of the 129 catfish processed yielded positive culture of Aeromonas species. Biochemical tests showed that the Aeromonas were motile species – Aeromonas hydrophila 48(87%), Aeromonas caviae 4(7%) and Aeromonas sobria 3(6%). The Aeromonas species exhibited highest resistance to ampicillin (100%) followed by tetracycline (89%), chloramphenicol (78%), ceftriaxone (71%), streptomycin (66%), amoxicillin-clavulanic acid (20%) and enrofloxacin (11%). None of the isolate was resistant to gentamicin, amikacin, ciprofloxacin, norfloxacin, ofloxacin, levofloxacin and ceftazidime. Fifty three (96%) of the Aeromonas isolates exhibited multidrug resistance. The Aeromonas isolates exhibited 23 resistance patterns to the antimicrobial agents tested.