Type 1 fimbriae (T1P) (T1P)

Type 1 fimbriae are filamentous, proteinaceous surface appendages found on Escherichia coli, particularly uropathogenic strains (UPEC), that play a pivotal role in bacterial pathogenesis (UniProt P08191). These structures are composed of a major pilin subunit, FimA, and a tip complex containing the FimH adhesin, a lectin that specifically recognizes and binds to terminal mannose residues on host cell surface glycoproteins, such as uroplakin Ia in the bladder (Wu et al., 1996, PNAS). This adhesion is the critical first step for colonization, biofilm formation, and invasion of the urothelium, leading to urinary tract infections (UTIs) and potentially more severe conditions like pyelonephritis (Sauer et al., 2019, Science). In the context of Crohn's disease, adherent-invasive E. coli (AIEC) utilize Type 1 fimbriae to colonize the intestinal mucosa via CEACAM6 receptors (Barnich et al., 2007, JCI). Therapeutic targeting of Type 1 fimbriae focuses on the FimH adhesin using mannosides or small-molecule inhibitors like Sibofimloc (EB8018) and GSK3882347, which competitively block the mannose-binding pocket (ClinicalTrials.gov NCT03709628). This anti-adhesive approach aims to prevent infection without exerting the selective pressure of traditional antibiotics, potentially reducing the development of antimicrobial resistance.

Other names

Type 1 piliMannose-sensitive fimbriaeFim fimbriaeFimH adhesin complex

Competitive inhibition of the FimH adhesin subunit, which prevents the binding of the fimbriae to mannosylated host cell receptors.