COLONIZATION FACTORS

The pili on enteropathogenic forms of E. coli facilitate adhesion of the bacteria to receptors (probably GM1 gangliosides) on gut epithelial cells and are often referred to as colonization or adherence factors. Colonization factor antigens may be plasmid coded, are essential for pathogenicity and are strain-specific, for example K88 (diarrhoea in piglets), CFAI and CFAII on strains causing similar disease in man.