More than 700 serotypes of E. coli have been identified. The different E. coli serotypes are distinguished by their "O" and "H" antigens on their bodies and flagella, respectively. The E. coli serotypes that are responsible for the numerous reports of contaminated foods and beverages are those that produce Shiga toxin, E. coli O157: H7 was first recognized as a food borne pathogen in 1982 during an investigation into an outbreak of hemorrhagic colitis (bloody diarrhea) associated with consumption of contaminated hamburgers. Present work was based on bacterial contamination of food samples...