Type 1 fimbriae adhesin FimH (FimH)

Type 1 fimbriae adhesin FimH is a critical virulence factor located at the tip of Type 1 pili in uropathogenic Escherichia coli (UPEC) (Sauer et al., 2000, Science). It functions as a lectin that specifically binds to D-mannose residues on uroplakin Ia receptors found on the luminal surface of bladder epithelial cells (Zhou et al., 2001, Journal of Biological Chemistry). This binding event is the initial and essential step for UPEC colonization of the urinary tract, enabling the bacteria to resist the shearing forces of urine flow (Hung et al., 2002, Molecular Microbiology). Beyond simple attachment, FimH-mediated binding triggers bacterial invasion into host cells and the formation of intracellular bacterial communities (IBCs), which contribute to recurrent infections and antibiotic resistance (Justice et al., 2004, PNAS). Because FimH is highly conserved among UPEC strains, it has become a primary target for anti-adhesion therapies, including mannoside antagonists like Sibofimloc and GSK3882347 (Zhong et al., 2022, Journal of Medicinal Chemistry). These drugs aim to block the FimH-mannose interaction, thereby preventing infection and facilitating the mechanical clearance of bacteria from the urinary tract without exerting the same selective pressure as traditional bactericidal antibiotics (Sivick & Mobley, 2010, Annals of the New York Academy of Sciences).

Other names

FimH adhesinType 1 pilus adhesinMannose-binding adhesinUropathogenic Escherichia coli adhesin

Competitive inhibition of the FimH lectin domain, preventing its binding to mannosylated glycoproteins (uroplakins) on the host bladder epithelium.