Prevalence and Antimicrobial Susceptibility Profile of E. coli O157:H7 in Fish Collected From Lake Ziway, Ethiopia

BACKGROUND: Fisheries play a significant role in food security, livelihood, and source of income in developing countries. Despite this, fish can spread infections. METHODS: A cross-sectional study with a simple random sampling approach was conducted to determine the prevalence and antibiotic susceptibility profile of Escherichia coli O157:H7 isolate from fish and fish handling equipment (knife) in Lake Ziway, Batu town, Ethiopia. To isolate and identify E. coli O157:H7, a total of 220 samples were collected by simple random sampling approach. Muscle and skin samples were collected from each 120 fish comprising Nile tilapia, common carp, and catfish obtained from landing sites and cold storage establishments of restaurants. One hundred samples were collected from fish processing knives and the hands of fish handlers. All the microbial identification and isolation procedures were conducted based selective culture media isolations. Antimicrobial susceptibility was conducted based on Kirby-Bauer disk diffusion protocols. FINDINGS: Over all prevalence of O157:H7 was found (4.5%). E. coli O157:H7 was detected in two (3.3%) of the total 100 fish handling equipment and eight (6.7%) of the total 120 fish samples. E. coli O157:H7 was isolated at 5.7% and 8% prevalence in frozen fish collected from restaurant cold storage and fresh fish collected immediately from landing site. Antimicrobial susceptibility test of E. coli O157:H7 isolates for kanamycin (30 ug), tetracycline (30 ug), cefoxitin (30 ug), erythromycin (20 ug), streptomycin (10 ug), sulfamethoxazole (25 ug), and ampicillin (10 ug) showed resistance to most antibiotics. The results indicate that E. coli O157:H7 was isolated from 10 samples from fish and fish handling equipment in this study. In addition, isolates were found resistant to penicillin and ampicillin. Kanamycin, tetracycline, and cefoxitin were found effective in inhibiting the growth of all of the isolates. CONCLUSION: The presence of E. coli O157:H7 isolates and its resistance to drugs pose significant economic and public health challenges. Thus, it requires implementing interventions like freezing and proper fish handling practices to minimize the level of contamination of fish in Ethiopia.