Abstract

Safe drinking water is essential for human health; however, microbial contamination of water sources remains a major public health concern in developing countries. This study investigated the antibiogram profile and molecular characterization of enteropathogenic Escherichia coli (EPEC) in selected drinking water sources in Kaduna metropolis, Nigeria. A total of eighteen water samples were collected in triplicates from six locations: Kawo (A), Unguwan Rimi (B), Tudun Wada (C), Sabon Tasha (D), Barnawa (E), and Kakuri (F). Standard microbiological methods, including Most Probable Number (MPN), total viable count, and biochemical characterization, were employed for isolation and identification of bacterial isolates. Antibiotic susceptibility testing was carried out using the disc diffusion method, while molecular detection of EPEC was performed using polymerase chain reaction (PCR) targeting virulence genes. Results revealed significant coliform contamination, with some samples recording ≥2400 MPN/100ml. Total viable bacterial counts ranged from 9.0 × 10⁵ to 1.61 × 10⁷CFU/ml. Escherichia coli, Salmonella spp., and Enterobacter spp. were identified, with E. coli being the most prevalent (55.9%). Antibiotic susceptibility testing showed that ciprofloxacin and pefloxacin exhibited the highest antibacterial activity against the isolates, whereas resistance was observed against commonly used antibiotics such as amoxicillin and augmentin. Molecular analysis confirmed the presence of EPEC strains through detection of characteristic gene fragments. The findings indicate widespread microbial contamination of drinking water sources in Kaduna metropolis, rendering them unsafe for human consumption. The presence of antibiotic-resistant EPEC highlights a significant public health risk, emphasizing the need for improved water treatment strategies, routine monitoring, and strengthened antimicrobial stewardship.