P-fimbriae of uropathogenic Escherichia coli (Pap)

P-fimbriae, also known as pyelonephritis-associated pili (Pap), are filamentous surface appendages found on uropathogenic Escherichia coli (UPEC) that play a critical role in the pathogenesis of upper urinary tract infections [Wikipedia]. These structures are assembled via the chaperone-usher pathway and consist of a major pilin rod (PapA) and a distal tip complex containing the PapG adhesin [NIH, 1.3.2]. PapG specifically recognizes and binds to Gal(alpha1-4)Gal-containing glycosphingolipids (globoseries) on the surface of host uroepithelial cells, particularly in the kidneys [NIH, 1.3.1]. This adherence is essential for bacterial colonization, resistance to the flushing action of urine, and the induction of a robust inflammatory response that contributes to tissue damage in pyelonephritis [NIH, 1.3.5]. Therapeutic strategies targeting P-fimbriae include the use of galabiose-based anti-adhesion agents, pilicides that disrupt pilus assembly, and vaccines designed to elicit protective antibodies against the fimbrial subunits [NIH, 1.2.1, 1.2.2].

Other names

Pyelonephritis-associated piliP piliPap fimbriaeGal-Gal fimbriaeP-fimbriae

Inhibition of bacterial adhesion to host uroepithelial cells by competitive binding to Gal(alpha1-4)Gal receptors and disruption of the chaperone-usher assembly pathway for pilus formation [NIH, 1.2.1, 1.2.2].