A total of one hundred raw milk samples were collected randomly from farmers, street vendors, supermarkets and dairy shops at Damietta Province. E. coli was detected in 21% of tested samples. Serological identification revealed that among the 21 isolates tested, O26: H11 was the most prevalent serotype 33.3% (7/21) while other serotypes including O91:H21, O113:H4 and O127:H6 were detected at a prevalence rates of 9.5% (2/21), 9.5% (2/21) and 14.2% (3/21), respectively. Seven other strains subdivided into O44:H18, O111:H2, O128:H2, O142, O146, O1, and O27 were detected once for each (1/21; 4.8%). Molecular characterization for
detection of genes stx 1 and stx 2 indicated that such virulence genes were present in 4/5 and 5/5, 2/2 and1/2, and 1/1and1/1, in E.coli 26:H11, O91:H21 and O111:H2, respectively. The potential health hazard of the isolated strains has been discussed.