Abstract:
Shiga toxin producing Escherichia coli (STEC) are dangerous foodborne pathogens
which represent a severe public health issue worldwide. Raw foods are considered as important
sources for STEC infection in human. In the current study, STEC contamination level was
determined in 39 raw foods and materials (chicken, beef, milk and water) collected from farms,
butchers, and retail markets in different localities of the Greater Cairo using Real-Time PCR (RT-
PCR). Moreover, the virulence genes of the isolated strains were characterized. STEC was
detected in three samples which represent about 8% of the tested samples, wherein they were all
beef samples. Two samples were positive for the eaeA (intimin) and stx2 gene, however; the third
sample was eaeA-negative and stx2-positive. The stx2 gene of STEC bacteria was the most
prevalent subtype identified in beef samples. Among the three positive samples, four STEC
strains were isolated; two strains belonged to O157 serogroup and the other two belonged to non-
O157 serogroup (O26).
