Relationship between EPEC and STEC

Venn diagram illustrating the relationship between enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) strains. Both the EPEC and the enterohemorrhagic E. coli (EHEC) subsets of STEC strains are capable of the attaching and effacing effect and are sometimes referred to as attaching and effacing E. coli (AEEC). The O157:H7 serotype is the most important clone of EHEC. EPEC can be divided into typical strains that produce bundle-forming pili and exhibit localized adherence and atypical strains with neither of these properties.