Prevalence and Molecular Characterization of Shiga Toxin Producing E. coli Isolated from Some Locally Produced Beef Products

Abstract

Shiga toxin-producing Escherichia coli (STEC) may cause severe gastrointestinal and systematic diseases in humans that result from consumption of meat products. STEC were isolated from some beef products on Trypticase Soya Broth and Sorbitol MacConkey agar supplemented with cefixime and tellurite supplements and were biochemically identified . Further identifications were performed including Vero cells cytotoxicity assay and PCR technique for specific VT1/VT2 and eae genes. It was obvious from the obtained resuts that the incidance of shiga-toxin producing E.coli were 22%, 12%, 10%, 16% and 2% in minced meat, beef burger, beef sausage, beef kofta and beef luncheon, respectively. The serovars of shiga-toxin producing E.coli isolated from the examined meat samples were O111, O26, O103, O119 ,O128 ,O86, O45 ,O146 ,O119 and O121. E.coli O111, O26, O103, O91, O86 and O119 that proved to have Stx1 and Stx2 genes. E.coli O128 and O121 had only Stx1, while E.coli O146 had only Stx2.Concerning the eae gene responsible for the attaching and effacing lesions, E. coli O111 and O26 isolates proved to possess such gene .In conclusion beef beef products constitute an important reservoir of STEC infection to man and it was decleared that PCR technique is the most rapid, sensitive and efficient approach for detection of STEC in beef products