Enterotoxigenic Escherichia coli colonization factor antigens (CFA) (CFA)

Enterotoxigenic Escherichia coli (ETEC) colonization factor antigens (CFAs) are a diverse group of surface-associated proteins, primarily fimbriae or pili, that mediate the initial attachment of the bacteria to the host's small intestinal epithelium (NIH, 2022). This adherence is a critical first step in ETEC pathogenesis, allowing the bacteria to colonize the gut and subsequently release heat-labile (LT) and heat-stable (ST) enterotoxins that cause watery diarrhea (MDPI, 2024). There are over 25 identified CFAs, with CFA/I, CS1-CS6, and CS21 being among the most prevalent in human infections (NIH, 2015). Because blocking colonization can prevent the entire disease process, CFAs are primary targets for the development of vaccines and monoclonal antibodies (PLOS, 2022). Current therapeutic strategies, such as the ETVAX vaccine and anti-CfaE monoclonal antibodies, focus on inducing broad-spectrum immunity against multiple CFA types to overcome the significant antigenic diversity of ETEC strains (NIH, 2017).

Other names

Colonization factorsColi surface antigensCS antigensETEC adhesinsFimbrial colonization factorsPiliFimbriae

Inhibition of bacterial adhesion to intestinal epithelial cells by blocking colonization factor-mediated attachment to host enterocytes (NIH, 2022).