摘要：Escherichia coli is one of the predominant enteric species in the human gut. However, there are small groups of E. coli, sometimes referred to as pathogenic E. coli that can cause severe diarrheal diseases in humans. Shiga toxigenic Escherichia coli (STEC), is on e of the pathogenic E. coli, and certain strains appear to be of greater virulence for humans, especially those belonging to serogroups O111 and O157 . Meat based sandwiches are well-recognized sources of E. coli. Ninety meat based sandwiches from street vendors (30 of each of liver, kofta and hawawshy) were collected in Assiut city . Twenty one (23.3%) of the examined sandwiches were contaminated with E.coli. D uplex PCR was used targeting for portions of the rfb (O-antigen-encoding) regions of E. coli serotypes O157 and O111, generating PCR products of 259 and 406 bp, respectively, that is specific for STEC, the share of STEC presence were 12 out of 90 (13.3%) of the examined samples. Overall, the obtained results detection of STEC in the street vended sandwiches was of a great importance as an indication of the unhygienic practices that followed, so it is advised to conduct further heating before con sumption and need of health education programs as well as hygienic practice for the food handlers and vendors.
关键词：E.coli; STEC; rfb regions; street vended sandwiches
