Escherichia coli K88ab fimbrial adhesin (K88ab)

The Escherichia coli K88ab antigen, also known as F4ab, is a filamentous fimbrial adhesin expressed by enterotoxigenic Escherichia coli (ETEC) [PMID: 15505004]. It plays a pivotal role in the pathogenesis of porcine enteric diseases by mediating the attachment of bacteria to specific receptors on the intestinal brush border [PMID: 25103148]. This colonization is essential for the subsequent delivery of enterotoxins that cause neonatal and post-weaning diarrhea [PMID: 16439311]. The K88ab variant is one of three major serotypes (ab, ac, and ad) and is composed primarily of the FaeG major subunit, which determines its binding specificity [UniProt: P02971]. In veterinary medicine, this antigen is a key component of vaccines designed to elicit protective antibodies that block bacterial adhesion [PMID: 18466615]. Therapeutic approaches targeting K88ab include the development of oral vaccines, egg yolk-derived antibodies, and competitive carbohydrate decoys to prevent infection [PMID: 22100218].

Other names

F4ab fimbriaeFaeG subunitK88ab pilusK88ab adhesinEnterotoxigenic E. coli K88ab

Induction of neutralizing antibodies to prevent bacterial attachment to host intestinal receptors; competitive inhibition of adhesion.