Identification, and Characterization of Escherichia coli O157:H7 from Animal-Derived Foods in Hawassa and Yirgalem, Sidama Region, Ethiopia

Escherichia coli O157:H7 is a significant foodborne pathogen with global public health implications. This study, conducted from December 2022 to July 2023 in Hawassa and Yirgalem, Sidama Region, Ethiopia, assessed the prevalence, molecular identification, and antimicrobial resistance of E. coli O157:H7 in animal-derived foods. A total of 298 samples including beef, raw milk, and fish were analyzed using culture methods, biochemical identification, and PCR. The overall prevalence of E. coli O157:H7 was 3.7%, with isolation rates of 6.25% in fish and 5.6% in beef; no isolates were found in milk samples (p = 0.036). Notably, meat from butcher shops exhibited a higher contamination rate (7.6%) compared to abattoir samples (3.4%), though this difference was not statistically significant (p = 0.445). Among fish samples, Nile Tilapia had a higher isolation rate (8.1%) than African Catfish (3.7%), with fish skin showing greater contamination (8.6%) than muscle tissue (3.4%). All E. coli O157:H7 isolates were susceptible to most tested antibiotics; however, resistance was observed against amoxicillin (81.8%), streptomycin (45.5%), and clindamycin (100%). Additionally, 45.5% of isolates exhibited multidrug resistance with an multidrug resistance (MDR) index of 0.27, though none produced extended-spectrum beta-lactamases (ESBLs). These findings underscore the necessity for stringent hygiene practices and effective monitoring of animal-derived foods to mitigate public health risks.