Prevalence of Multidrug Resistant Escherichia Coli in Fish, Fish Handlers and Water in Sokoto State Nigeria

Fish and sea-food constitute an important and cheap food source of protein for many groups of the world population. Fish contains good quality protein and other necessary nutrients that make it a valuable food. This study investigates the occurrence and antimicrobial resistance profiles of E. coli isolated from fish, fish handlers, and water sources in Sokoto State, Nigeria. Aquatic animals, especially fish, constitute a significant source of animal protein globally, with growing aquaculture practices implicated in environmental dissemination of antibiotic resistance due to extensive antimicrobial use. E. coli, a known opportunistic pathogen and vector for antibiotic resistance genes through horizontal gene transfer, poses public health risks, particularly when multidrug-resistant (MDR) strains prevail. The study was a cross-sectional descriptive survey conducted over six months, involving sample collection from institutional fish farms, rivers, lakes, and fish handlers. Isolation and identification of E. coli employed standard microbiological and biochemical methods, followed by antimicrobial susceptibility testing using the Kirby-Bauer disc diffusion method on 15 antibiotics, interpreted per CLSI guidelines. Out of 360 samples, E. coli was isolated in 5.83% overall prevalence, with higher detection in human samples (8%) compared to fish (3.33%) and water (5.71%). All isolates exhibited multidrug resistance, showing 100% resistance to Gentamycin, Quinupristin, Mupirocin, Amoxicillin-Cloxacillin, Ceftazidime, Cefpodoxime, Ertapenem, and Imipenem. Resistance levels varied for other antibiotics, with highest resistance against Tetracycline (95.2%) and moderate resistance for Sulphamethoxazole (38.1%) and Azithromycin (33.3%). Multiple antibiotic resistance index (MARI) values ranged from 0.6 to 0.8, indicating high-risk contamination sources. These findings highlight the presence of MDR E. coli in the aquatic environment and associated human contacts, underscoring the public health risk and the necessity for surveillance, rational antibiotic use, and improved sanitation in aquaculture and fish handling practices in Nigeria. This study fills a critical research gap in northwest Nigeria where limited data exist on antibiotic resistance in aquatic settings, providing essential baseline data to inform policy and control measures against antimicrobial resistance in aquatic food chains and human populations.