title: Pilicide ec240 disrupts virulence circuits in uropathogenic Escherichia coli.
abstract: Chaperone-usher pathway (CUP) pili are extracellular organelles produced by Gram-negative bacteria that mediate bacterial pathogenesis. Small-molecule inhibitors of CUP pili, termed pilicides, were rationally designed and shown to inhibit type 1 or P piliation. Here, we show that pilicide ec240 decreased the levels of type 1, P, and S piliation. Transcriptomic and proteomic analyses using the cystitis isolate UTI89 revealed that ec240 dysregulated CUP pili and decreased motility. Paradoxically, the transcript levels of P and S pilus genes were increased during growth in ec240, even though the level of P and S piliation decreased. In contrast, the most downregulated transcripts after growth in ec240 were from the type 1 pilus genes. Type 1 pilus expression is controlled by inversion of the fimS promoter element, which can oscillate between phase on and phase off orientations. ec240 induced the fimS phase off orientation, and this effect was necessary for the majority of ec240's inhibition of type 1 piliation. ec240 increased levels of the transcriptional regulators SfaB and PapB, which were shown to induce the fimS promoter phase off orientation. Furthermore, the effect of ec240 on motility was abolished in the absence of the SfaB, PapB, SfaX, and PapX regulators. In contrast to the effects of ec240, deletion of the type 1 pilus operon led to increased S and P piliation and motility. Thus, ec240 dysregulated several uropathogenic Escherichia coli (UPEC) virulence factors through different mechanisms and independent of its effects on type 1 pilus biogenesis and may have potential as an antivirulence compound.
  
  
  OBJECTIVE
  CUP pili and flagella play active roles in the pathogenesis of a variety of Gram-negative bacterial infections, including urinary tract infections mediated by UPEC. These are extremely common infections that are often recurrent and increasingly caused by antibiotic-resistant organisms. Preventing piliation and motility through altered regulation and assembly of these important virulence factors could aid in the development of novel therapeutics. This study increases our understanding of the regulation of these virulence factors, providing new avenues by which to target their expression.
authors.affiliation: Department of Molecular Microbiology and Microbial Pathogenesis and Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Greene
authors.affiliation: Department of Molecular Microbiology and Microbial Pathogenesis and Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
authors.forename: Jerome S
authors.initials: JS
authors.lastname: Pinkner
authors.forename: Erik
authors.initials: E
authors.lastname: Chorell
authors.affiliation: Department of Molecular Microbiology and Microbial Pathogenesis and Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
authors.forename: Karen W
authors.initials: KW
authors.lastname: Dodson
authors.affiliation: Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Carrie L
authors.initials: CL
authors.lastname: Shaffer
authors.affiliation: Department of Molecular Microbiology and Microbial Pathogenesis and Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.
authors.forename: Matt S
authors.initials: MS
authors.lastname: Conover
authors.affiliation: The Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Livny
authors.affiliation: Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Hadjifrangiskou
authors.forename: Fredrik
authors.initials: F
authors.lastname: Almqvist
authors.affiliation: Department of Molecular Microbiology and Microbial Pathogenesis and Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA Hultgren@wusm.wustl.edu.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Hultgren
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000187:drug effects*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects; D056689:Uropathogenic Escherichia coli / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D014774:Virulence / Q000187:drug effects; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D037521:Virulence Factors