P-fimbria (Pap pilus) (Pap)

P-fimbriae, also known as pyelonephritis-associated pili (Pap), are hair-like surface appendages expressed by uropathogenic Escherichia coli (UPEC) that are critical for the colonization of the upper urinary tract (Roberts et al., 1994). These structures are essential virulence factors that facilitate the colonization of the upper urinary tract by binding specifically to Gal(alpha1-4)Gal-containing glycolipids on renal epithelial cells (Dodson et al., 2001). The binding is primarily mediated by the PapG adhesin, a protein located at the distal tip of the fimbria. Because P-fimbriae are crucial for the transition from bladder infection (cystitis) to kidney infection (pyelonephritis), they are significant targets for anti-adhesion therapies. Therapeutic approaches include the use of galabioside analogs to competitively inhibit binding and pilicides that disrupt the chaperone-usher pathway required for pilus assembly (Pinkner et al., 2006). Additionally, cranberry-derived proanthocyanidins have been shown to inhibit the adhesion of P-fimbriated E. coli to uroepithelial cells (Howell et al., 2005). Targeting these fimbriae offers a potential alternative to traditional antibiotics, which may help in reducing the emergence of antimicrobial resistance by disarming the pathogen's ability to colonize rather than killing the bacteria directly.

Other names

Pyelonephritis-associated piliPap piliGal-Gal piliP-fimbriated Escherichia coli adhesinPapG adhesin

Competitive inhibition of PapG adhesin binding to host Gal(alpha1-4)Gal receptors and disruption of pilus biogenesis via the chaperone-usher pathway.