commensal bacterium that is classified as a member of the Enterobacteriaceae family (Tenaillon et al., 2010). It is an oxidase-negative facultative anaerobe with an optimal growth PH 6.0-7.0 and temperature of 37 °C. It can ferment glucose, lactose, and sucrose. However, certain laboratory strains of E. coli can proliferate at a temperature of 49 °C (Fotadar et al., 2005). It is found in the gastrointestinal tract of human and animals, but some species are known as pathogenic such as E. coli O157:H7 (Khudhir,