Type 1 pilus tip adhesin FimH (FimH)

Type 1 pilus tip adhesin FimH (FimH) is a 30 kDa lectin-like protein located at the distal end of Type 1 fimbriae in uropathogenic Escherichia coli (UPEC) [UniProt P08191]. It serves as the primary mediator of bacterial adhesion to the bladder epithelium by specifically binding to D-mannose residues on host glycoproteins, such as uroplakin Ia [Nature Reviews Microbiology, 2016]. This attachment is a critical initial step in the pathogenesis of urinary tract infections (UTIs), as it prevents the mechanical flushing of bacteria by urine and triggers host cell signaling pathways that lead to bacterial invasion [PubMed, 28841135]. Once internalized, UPEC can form intracellular bacterial communities (IBCs), which are resistant to both the host immune response and conventional antibiotic treatments, often leading to recurrent infections [Nature, 2017]. Therapeutic strategies targeting this interface primarily involve small-molecule FimH antagonists, such as mannosides, which competitively occupy the carbohydrate-binding domain of the adhesin [Journal of Medicinal Chemistry, 2018]. These anti-adhesive drugs, including clinical candidates like Sibofimloc and GSK3882347, aim to prevent colonization and facilitate bacterial clearance without the selective pressure associated with traditional bactericidal antibiotics [ClinicalTrials.gov].

Other names

FimHMannose-binding lectin FimHType 1 fimbrial adhesinD-mannose-specific adhesinType 1 pilus tip adhesin

Competitive inhibition of the FimH carbohydrate-binding domain (CBD) to prevent bacterial attachment to mannosylated host uroplakins [Nature, 2017].