title: The role of H4 flagella in Escherichia coli ST131 virulence.
abstract: Escherichia coli sequence type 131 (ST131) is a globally dominant multidrug resistant clone associated with urinary tract and bloodstream infections. Most ST131 strains exhibit resistance to multiple antibiotics and cause infections associated with limited treatment options. The largest sub-clonal ST131 lineage is resistant to fluoroquinolones, contains the type 1 fimbriae fimH30 allele and expresses an H4 flagella antigen. Flagella are motility organelles that contribute to UPEC colonisation of the upper urinary tract. In this study, we examined the specific role of H4 flagella in ST131 motility and interaction with host epithelial and immune cells. We show that the majority of H4-positive ST131 strains are motile and are enriched for flagella expression during static pellicle growth. We also tested the role of H4 flagella in ST131 through the construction of specific mutants, over-expression strains and isogenic mutants that expressed alternative H1 and H7 flagellar subtypes. Overall, our results revealed that H4, H1 and H7 flagella possess conserved phenotypes with regards to motility, epithelial cell adhesion, invasion and uptake by macrophages. In contrast, H4 flagella trigger enhanced induction of the anti-inflammatory cytokine IL-10 compared to H1 and H7 flagella, a property that may contribute to ST131 fitness in the urinary tract.
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.|Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Asha
authors.initials: A
authors.lastname: Kakkanat
authors.affiliation: Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Makrina
authors.initials: M
authors.lastname: Totsika
authors.affiliation: Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Kolja
authors.initials: K
authors.lastname: Schaale
authors.affiliation: School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Duell
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.|Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Alvin W
authors.initials: AW
authors.lastname: Lo
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.|Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Minh-Duy
authors.initials: MD
authors.lastname: Phan
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.|Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Danilo G
authors.initials: DG
authors.lastname: Moriel
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.|Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Beatson
authors.affiliation: Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.|Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Sweet
authors.affiliation: School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
authors.forename: Glen C
authors.initials: GC
authors.lastname: Ulett
authors.affiliation: School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.|Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Schembri
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics; D001422:Bacterial Adhesion / Q000235:genetics; D002465:Cell Movement / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity; D036781:Fimbriae Proteins / Q000235:genetics; D005407:Flagella / Q000235:genetics*; D024841:Fluoroquinolones / Q000008:administration & dosage; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics; D008826:Microbial Sensitivity Tests; D014552:Urinary Tract Infections / Q000235:genetics* / Q000382:microbiology; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D018830:Adhesins, Escherichia coli; D024841:Fluoroquinolones; C508609:IL10 protein, human; C058769:fimH protein, E coli; D016753:Interleukin-10; D036781:Fimbriae Proteins; D001618:beta-Lactamases