Enterohemorrhagic Escherichia coli (EHEC) causes over 70,000 episodes of foodborne diarrhea annually in the United States. The early sequence of events that precede life-threatening hemorrhagic colitis and hemolytic uremic syndrome is not fully understood due to the initial asymptomatic phase of the disease and the lack of a suitable animal model. We determined the initial molecular events in the interaction between EHEC and human colonic epithelium.