Virulence Genes and Phenotypic Evaluation of the Antibiotic Resistance of Vero Toxin Producing <i>Escherichia coli</i> Recovered From Milk, Meat, and Vegetables

Abstract

Background: Resistant and virulent strains of Shiga toxin producing Escherichia coli (STEC) are one of the main prevalence sources of food infection due to consumption of meat, milk, and vegetables. Objectives: This study was conducted to assess the frequency of virulence factors and phenotypes of antibiotic- resistant STEC bacteria recovered from meat, milk, and vegetable samples. Methods: In this study, 280 samples were assessed. Escherichia coli isolates were assessed by PCR and disk diffusion. Results: Out of 280 samples, 59 (21.07%) were contaminated with E. coli. Vegetables had the highest prevalence (31.25%), while raw meat (14%) had the lowest. Stx1, eae, and ehly genes were found in all enterohemorrhagic Escherichia coli (EHEC) bacteria. Moreover, 21 out of 59 E. coli strains were STEC (35.59%). Shiga toxin producing E. coli strains showed the most resistance against ampicillin (100%), gentamycin (90.47%), tetracycline (85.71%), and ciprofloxacin (71.42%). Shiga toxin producing E. coli strains harbored resistance to at least 2 antibiotics (100%). Conclusions: Judicious prescription of imipenem and cotrimoxazole based on the results of disk diffusion and also proper washing of the vegetables, cooking of the meat, and boiling of the milk before consumption can control and reduce the risk of incidence of food poisoning due to the virulent and resistant STEC strains.