Phenotypic screening of multidrug-resistant E. coli from water and fish collected from different fish farms within Abakaliki metropolis, Nigeria

The aim of this study was to screen fish farm water and fishes reared in fish farms within Abakaliki metropolis for multi-drug resistant Escherichia coli. Exactly 30 fish samples and 30 water samples were obtained from 10 different fish farms using sterile bottles from January to June, 2018. Samples were analyzed by standard microbiology methods. Susceptibility test to antibiotics was done by Kirby-Bauer disc diffusion technique. Double-disc synergy test was used to screen isolates for Extended Spectrum Beta-Lactamase (ESBL)-production. Exactly 54 (60%) E. coli and 12 (40%) E. coli were recovered from 90 different fish parts and 30 farm water samples, respectively. Isolates exhibited resistance (54% - 100%) to ceftazidime, aztreonam, cefotetan, cefuroxime, cefoxitin, piperacillin/tazobactam, ofloxacin, and ceftriaxone, but were susceptible to imipenem (80%), cefotaxime (60%), and gentamicin (57%). All the E. coli isolates form water and fish samples were negative for ESBL production.  An average multiple antibiotic resistance index (MARI) value of 0.71 was recorded for the isolates. High prevalence of E. coli with multidrug-resistant traits in fish and water samples in our study area is a serious public health concern as this will make the treatment of infections, especially E. coli-associated foodborne diseases very difficult, thus leading to increase in health care cost, morbidity, and mortality. Key words: Escherichia coli, fish farm, multidrug-resistance, farm water, fish.