Enterotoxigenic Escherichia coli adhesin (ETEC adhesin)

Enterotoxigenic Escherichia coli (ETEC) adhesins are a diverse group of surface-exposed proteins that mediate the critical first step of bacterial attachment to the host intestinal epithelium (Fleckenstein et al., 2010). These adhesins, often referred to as colonization factors (CFs) or colonization factor antigens (CFAs), allow the bacteria to resist mechanical clearance by peristalsis and facilitate the delivery of enterotoxins (Qadri et al., 2005). Structurally, they can be classified into fimbrial, fibrillar, and non-fimbrial types, with over 25 distinct varieties identified, including CFA/I and the Coli Surface (CS) antigen family (Wolf, 1997). Because adhesion is essential for pathogenesis, these proteins are the primary focus for vaccine development, such as the oral inactivated vaccine ETVAX, which targets multiple common CFs (Björk et al., 2019). Therapeutic strategies involve inducing mucosal IgA antibodies that bind to these adhesins, thereby sterically hindering the bacteria's ability to colonize the gut (Svennerholm, 2011). However, the high degree of antigenic variability among ETEC strains remains a significant challenge for achieving broad-spectrum protection (Turner et al., 2006).

Other names

Colonization factorColonization factor antigenCFAColi surface antigenCS antigenFimbriaePiliEtpATibAEaeH

Inhibition of bacterial attachment to host intestinal epithelial cells by inducing neutralizing antibodies or competitive binding.