Molecular Determinants of Multiple Antibiotic Resistant E. coli Isolated from Food of Animal Origin

Multiple antibiotic-resistant E. coli usually contaminates foods of animal origin representing a major threat to public health. The purpose of this study was to demonstrate multiple antibiotic-resistant E. coli as a serious food contaminating bacteria in milk, meat and their products. One hundred and twenty five (125) samples were collected from meat, milk and their products from different markets in Beni-Suef and Giza Governorates, Egypt. The isolated E. coli were subjected to antimicrobial sensitivity testing against ampicillin, tetracycline and streptomycin and resistance genes were detected using polymerase chain reaction (PCR). Out of 125 samples, 41 E. coli were isolated. Serogrouping of E. coli isolates revealed O157, O44, O119, O168, O6, O158, O164, O126 and O125 serogroups. Most of E. coli isolateswere multidrug resistant (MDR). E. coli isolates were resistant to ampicillin, amoxicillin, kanamycin, tetracycline and streptomycin with percentages of 63.4, 61, 53.7, 41.5 and 14.6%, respectively. Out of tetracycline resistant isolates (n=17), 14 isolates harbored tetB gene (82.4%), while six isolates harbored tetA gene (35.3%). Meanwhile, both tetA and tetB were harbored in 4 isolates with a percentage of 23.5% Ampicillin resistance gene blaTEM found in 76.5% of the ampicillin resistant isolates. Streptomycin resistant genes aadA1 and aadA2 were represented in 50% and 0% of the isolates, respectively. Foods of animal origin is considered an important source of multiple antibiotic resistant E. coli that can be a major source of food-borne diseases.