Escherichia coli K88ac fimbrial protein (K88ac) (K88ac)

The Escherichia coli K88ac fimbrial protein, also known as F4ac, is a major surface-exposed proteinaceous appendage found on enterotoxigenic E. coli (ETEC) strains that primarily infect swine (UniProt: P02971). These fimbriae are composed of polymerized subunits, with FaeG serving as the major subunit and primary adhesin responsible for binding to specific glycoprotein receptors on the brush border of porcine intestinal epithelial cells (PubMed: 15659680). This binding is a critical first step in bacterial colonization and the subsequent delivery of enterotoxins, leading to severe neonatal and post-weaning diarrhea (PubMed: 22434735). Because of its essential role in pathogenesis, K88ac is a primary target for the development of veterinary vaccines, including oral and parenteral formulations designed to induce protective mucosal immunity (PubMed: 11055614). Additionally, research focuses on anti-adhesion strategies using carbohydrate analogs or specific antibodies to block the interaction between the fimbriae and host receptors. The specificity of the K88ac variant is determined by the primary sequence of the FaeG subunit, which dictates the host range and tissue tropism of the bacteria. Effective targeting of this antigen is crucial for reducing the economic impact of ETEC infections in the swine industry.

Other names

F4ac fimbriaeK88ac adhesinFaeG proteinF4 fimbrial antigen

Inhibition of bacterial adhesion to the intestinal mucosa and induction of neutralizing antibodies.