Occurrence and antibiotics resistance patterns of Escherichia coli isolated from fast-foods at selected eating outlets around Makerere University, Kampala

Abstract

Contamination of fast foods with Escherichia coli is a public health concern, especially in urban areas with high food vending as an economic activity. The emergence of antibiotic-resistant E. coli strains further exacerbates foodborne disease management. This study aimed to determine the prevalence and microbial load of E. coli in fast foods sold around Makerere University, Kampala as well as assess the antibiotic susceptibility profiles of the isolates. A cross-sectional study was conducted in which 72 fast food samples were collected from selected fast-food selling points around Makerere University (such as: Kikoni, Kikumi Kikumi, and within campus). Samples were aseptically collected, transported and cultured on Coliform Chromogenic Agar (CCA). E. coli isolates were confirmed biochemically and positive isolates were tested for antimicrobial susceptibility using the Kirby-Bauer standard disk diffusion method. Of the 72 samples tested, 4 (5.6%) were positive for E. coli. The mean microbial load among the positive samples was 5.75 ×10² CFU/g. Antibiotic susceptibility testing revealed 100% resistance to Amoxicillin-clavulanate, 75% to both Tetracycline and Trimethoprim-sulfamethoxazole, while Imipenem and Ceftriaxone exhibited 100% susceptibility. Overall, 42.8% of the results showed resistance to at least one of the common antibiotics. Though E. coli prevalence in fast foods was low, the presence of multidrug-resistant strains is of concern. These findings call for improved hygiene practices among vendors, routine food safety surveillance, and measures to mitigate antimicrobial resistance.