Enterohemorrhagic Escherichia coli Adhesins

Among the thousands of bacterial species contained within the intestinal gut flora, it is accepted that each species requires the use of adhesin proteins, or some combination thereof, that bring the bacteria closer to the epithelia and allow them to colonize the intestine. In a similar way, enteric pathogens also require surface-localized adhesins for colonization of the host intestine and eventual establishment of disease. Enterohemorrhagic Escherichia coli (EHEC) and, in general, Shiga toxin-producing E. coli (STEC) strains are known to contain a large number of proteins responsible for adhesion and contribute to establishment, persistence, and tissue tropism observed during infection with these pathogens. Understanding how these adhesins work is critical to having a full picture of the pathogenic and pathophysiological process associated with EHEC. Further, because adhesins play such an important role in virulence, they are targets for therapeutic intervention. Thus, this review summarizes the current knowledge on the adhesive proteins in EHEC, emphasizing up-to-date information and discussing gaps in knowledge and future directions in the study of these virulence factors.