Fimbrial adherence factors from pathogenic Escherichia coli strains.

The ability of many bacteria to adhere to specific host tissues is a factor of primary importance in diseases such as bacterial diarrhea, gonorrhea and bladder and kidney infections. Specific adherence allows the pathogen to resist removal by the flushing and cleaning mechanisms of the host, and determines the site of microbial invasion. In many bacteria, including pathogenic E. coli, such an adhesion is mediated by fimbria, of which several species have been characterized. A single fimbria consists of hundreds of identical subunits. Each provides an attachment site for a host epithelial receptor, and by subunit-subunit interaction furnishes the necessary structural integrity of the fimbria superstructure. Furthermore, segments of the fimbrial peptide chain are able to provoke an immune response in the host. In order to define structural and functional parameters in fimbriae one may use the information and inherent constraints provided in the molecular data on these bacterial adhesins now available.