title: Suppression of type 1 pilus assembly in uropathogenic Escherichia coli by chemical inhibition of subunit polymerization.
abstract: OBJECTIVE
  To identify and to characterize small-molecule inhibitors that target the subunit polymerization of the type 1 pilus assembly in uropathogenic Escherichia coli (UPEC).
  
  
  METHODS
  Using an SDS-PAGE-based assay, in silico pre-filtered small-molecule compounds were screened for specific inhibitory activity against the critical subunit polymerization step of the chaperone-usher pathway during pilus biogenesis. The biological activity of one of the compounds was validated in assays monitoring UPEC type 1 pilus biogenesis, type 1 pilus-dependent biofilm formation and adherence to human bladder epithelial cells. The time dependence of the in vivo inhibitory activity and the overall effect of the compound on UPEC growth were determined.
  
  
  RESULTS
  N-(4-chloro-phenyl)-2-{5-[4-(pyrrolidine-1-sulfonyl)-phenyl]-[1,3,4]oxadiazol-2-yl sulfanyl}-acetamide (AL1) inhibited in vitro pilus subunit polymerization. In bacterial cultures, AL1 disrupted UPEC type 1 pilus biogenesis and pilus-dependent biofilm formation, and resulted in the reduction of bacterial adherence to human bladder epithelial cells, without affecting bacterial cell growth. Bacterial exposure to the inhibitor led to an almost instantaneous loss of type 1 pili.
  
  
  CONCLUSIONS
  We have identified and characterized a small molecule that interferes with the assembly of type 1 pili. The molecule targets the polymerization step during the subunit incorporation cycle of the chaperone-usher pathway. Our discovery provides new insight into the design and development of novel anti-virulence therapies targeting key virulence factors of bacterial pathogens.
authors: Structural and Molecular Microbiology, VIB Department of Structural Biology, VIB, Pleinlaan 2, 1050 Brussels, Belgium.
authors: Alvin W H
authors: AW
authors: Lo
authors: Karen
authors: K
authors: Van de Water
authors: Paul J
authors: PJ
authors: Gane
authors: A W Edith
authors: AW
authors: Chan
authors: David
authors: D
authors: Steadman
authors: Kiri
authors: K
authors: Stevens
authors: David L
authors: DL
authors: Selwood
authors: Gabriel
authors: G
authors: Waksman
authors: Han
authors: H
authors: Remaut
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects; D002460:Cell Line; D004847:Epithelial Cells / Q000382:microbiology; D010861:Fimbriae, Bacterial / Q000187:drug effects*; D006801:Humans; D046911:Macromolecular Substances / Q000378:metabolism*; D055503:Protein Multimerization / Q000187:drug effects*; D021122:Protein Subunits / Q000378:metabolism*; D056689:Uropathogenic Escherichia coli / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D046911:Macromolecular Substances; D021122:Protein Subunits
keywords: UPEC; anti-virulence; chaperone–usher pathway; type 1 pili; urinary tract infections