Isolation and Molecular Characterization of Shiga Toxin-Producing Escherichia Coli in Beef Retail Markets

Shiga toxin-producing Escherichia coli (STEC) are food borne pathogens cause mild to serious diseases, leading to people death. This study records the prevalence and characterization of STEC O157 and non-O157 in commercial ground beef and instruments samples ( meat tables, knives, meat mincing machines) obtained from 25 retail markets in Kafer El-sheikh governorate. The STEC isolates were serotyped and virulence genes as stx1 (Shiga toxin 1), stx2 (Shiga toxin 2) and eae (intimin) were determined. STEC O157 were identified in 11 (14.6 %) of raw beef samples and 8 (10.6%) in instrument samples, while STEC non-O157 (O128, O78, O111, O26 and O119) were present in 6(8%) in raw beef samples and 9 (12%) in instruments samples. Among isolated strains , the prevalent genotype for O157 were stx1,stx2and eae while for STEC non-O157 were stx1 , stx2 and eae in O111, stx1 and stx2 in O26 , stx1 in O128 and O119 , stx2 in O78 . In conclusion, cross- contamination between meat and the environment could be suspected.