Antibiogram of Escherichia coli O157:H7 from Fresh Vegetables sold in Jos Metropolis Nigeria

Abstract

Fresh vegetables are essential components of healthy diets, yet microbial contamination along the supply chain poses growing safety risks. This study determined the antibiogram of E. coli O157:H7 isolated from fresh vegetables sold in Jos metropolis, Nigeria. A total of 60 vegetable samples were analysed for bacterial load, E. coli identification using API 20E and subsequently E. coli O157:H7 was confirmed on cefixime‑tellurite sorbitol‑MacConkey agar. Susceptibility testing was done using Kirby‑Bauer method, with indices calculated. Total aerobic mesophilic count (TAMC) ranged from 1.60 × 10⁴ ± 2.48 × 10³ to 5.27 × 10⁶ ± 2.79 × 10⁶ CFU/g with no variation (p > 0.05) across vegetable types or market outlets. Total coliform counts varied significantly (p = 0.006) and exceeded the ICMSF limit of 100 MPN/g. Escherichia coli O157:H7 prevalence was 39.58% higher than generic E. coli (35.42%; χ² = 139.60, df = 7, p < 0.0001) with 50% positivity in leafy vegetables. Market occurrence differed (χ² = 9.16, df = 2, p = 0.010), with highest in samples from Farin‑Gada (62.50%), followed by Bukuru (43.75%) and then Building Materials (12.50%). The isolates were susceptible to ciprofloxacin (100%) and 94.74% to ceftaroline, but highly resistant to ampicillin (89.47%), and tetracycline (84.21%). Overall, 68.42% were multidrug‑resistant, with MAR indices ranged 0.17–0.83, with 84.21% ≥ 0.33, indicating high antimicrobial selection pressure. These findings demonstrate that fresh vegetables in Jos metropolis harboured E. coli O157:H7 at levels posing significant public health risk.