title: Survival of uropathogenic Escherichia coli in the murine urinary tract is dependent on OmpR.
abstract: Uropathogenic Escherichia coli (UPEC) can grow in environments with significantly elevated osmolarities, such as murine and human urinary tracts. OmpR is the response regulator part of a two-component OmpR-EnvZ regulatory system that responds to osmotic stresses. To determine the role of OmpR in UPEC survival, a DeltaompR mutant was created in the UPEC clinical isolate NU149. The DeltaompR mutant had a growth defect compared with the wild-type strain under osmotic stress conditions; this defect was complemented by the full-length ompR gene on a plasmid, but not with a mutant OmpR with an alanine substitution for aspartic acid at the phosphorylation site at position 55. Furthermore, the DeltaompR mutant displayed up to 2-log reduction in bacterial cell numbers in murine bladders and kidneys compared with wild-type bacteria after 5 days of infection. The ability of the bacteria to survive was restored to wild-type levels when the DeltaompR mutant strain was complemented with wild-type ompR, but not when the alanine-substituted ompR gene was used. This study has fulfilled molecular Koch's postulates by showing the pivotal role OmpR plays in UPEC survival within the murine urinary tract.
authors.affiliation: Department of Microbiology, University of Wisconsin-La Crosse, 1725 State St., La Crosse, WI 54601, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Schwan
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001426:Bacterial Proteins / Q000502:physiology*; D004926:Escherichia coli / Q000254:growth & development / Q000472:pathogenicity; D005260:Female; D005816:Genetic Complementation Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D016297:Mutagenesis, Site-Directed; D009994:Osmolar Concentration; D015534:Trans-Activators / Q000502:physiology*; D014551:Urinary Tract / Q000382:microbiology*; D014552:Urinary Tract Infections / Q000382:microbiology*; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D015534:Trans-Activators; C112177:osmolarity response regulator proteins