Prevalence and antimicrobial resistance of Shiga toxin-producing in milk and dairy products in Egypt.

Food contaminated with Shiga toxin-producing (STEC) represents a hazardous public health problem worldwide. Therefore, the present study was performed to elucidate the virulent and antimicrobial resistance characteristics of STEC isolated from milk and dairy products marketed in Egypt. A total of 125 samples (raw market milk, bulk tank milk, Kareish cheese, white soft cheese, and small scale-produced ice cream, 25 each) were collected for determination the prevalence and antimicrobial resistance profiling of STEC. Thirty-six STEC isolates were recovered from milk and dairy products. Serological analysis illustrated that three isolates were O157:H7 and 33 isolates belonged to different serotypes. Molecular examination indicated that all isolates harboured and/or genes, 14 isolates expressed gene and 3 isolates possessed gene. Antimicrobial resistance profiling of the isolates was both phenotypically and genetically examined. Interestingly, 31 out of 36 (86.11%) isolates were multidrug-resistant and harboured the extended-spectrum β-lactamase encoding genes, namely, , and . Moreover, 12 isolates (33.33%) harboured plasmid-mediated quinolone resistant gene, . The overall conclusion of the current investigation indicated insufficient hygienic measures adopted during milking, handling, and processing leading to development of pathogenic and multidrug-resistant STEC.