title: The Niche forEscherichia coliSequence Type 131 Among Veterans: Urinary Tract Abnormalities and Long-Term Care Facilities.
abstract: Background.Antimicrobial resistance amongEscherichia coliis increasing, driven largely by the global emergence of sequence type 131 (ST131). However, the clinical significance of ST131 status is unknown. Among veterans, we assessed whether ST131 causes more severe, persistent, or recurrence-prone infections than non-ST131E. coli.Methods.Isolates were assessed by polymerase chain reaction for membership in ST131 and relevant subclones thereof (H30R andH30Rx) and by broth microdilution for susceptibility to 11 antibiotics. Clinical and epidemiological data were systematically abstracted from the medical record. Between-group comparisons were made usingttests and Fisher's exact test.Results.Of the 311 uniqueE. coliisolates, 61 (19.6%) represented ST131. Of these, most (51 of 61, 83.6%) represented theH30R subclone; only 5 of 51 (9.8%) representedH30Rx. Relative to non-ST131 and non-H30R isolates, neither ST131 norH30R were associated with more severe disease, worse clinical outcomes, or more robust hosts. Instead, both were more likely to be isolated from patients without manifestations of infection (for ST131, 36.1% vs 21.2% [P= .02]; forH30R, 39% vs 21% [P= .008]) and who had prior healthcare contact or long-term care facility (LTCF) exposure (for ST131, 33% vs 14% [P= .002]; forH30R, 37% vs 14% [P< .001]). Despite a greater likelihood of discordant initial therapy, outcomes did not differ between ST131 andH30R isolates vs otherE. coliisolates.Conclusions.Among veterans, ST131 and itsH30R subclone were associated with LTCF-exposed hosts but not with worse outcomes.
authors.affiliation: Infectious Diseases Section; Departments of Medicine.
authors.forename: Dimitri M
authors.initials: DM
authors.lastname: Drekonja
authors.affiliation: Psychiatry , University of Minnesota Medical School , Minneapolis.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kuskowski
authors.affiliation: Research Service , Minneapolis Veterans Affairs Healthcare System , Minnesota.
authors.forename: Ruth
authors.initials: R
authors.lastname: Anway
authors.affiliation: Infectious Diseases Section; Departments of Medicine.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Johnston
authors.affiliation: Infectious Diseases Section; Research Service, Minneapolis Veterans Affairs Healthcare System, Minnesota.
authors.forename: James R
authors.initials: JR
authors.lastname: Johnson
keywords: Escherichia coli; antimicrobial resistance; epidemiology; virulence