title: Antibiotic sensitivity profiles do not reliably distinguish relapsing or persisting infections from reinfections in cats with chronic renal failure and multiple diagnoses of Escherichia coli urinary tract infection.
abstract: Older cats with chronic renal failure (CRF) commonly develop urinary tract infections (UTI). Uropathogenic Escherichia coli (UPEC) is identified as the causal agent of UTI in most affected cats. Infections are often complicated, and UPEC infections may persist or recur in these cats. Antibiotic sensitivity profiles have been used to distinguish relapsing or persisting UTI from reinfection by different clones of the same species. However, the accuracy with which antibiograms discriminate different urinary E coli clones in cats is uncertain. We studied 17 cystocentesis-derived UPEC isolates collected from 5 cats with stable CRF and multiple diagnoses of UTI. UTIs were classified as relapses versus persistent infections or reinfections using antibiograms determined by Kirby-Bauer discs and Etests. Subsequently, clonality of UPEC isolates was determined by pulsed-field gel electrophoresis (PFGE). A comparison of PFGE results with antibiograms indicated that antibiotic resistance patterns varied considerably within several individual E coli clones. Both antibiotic susceptibility tests differentiated between relapsing or persistent infections and reinfections with only 58% overall efficiency. Thus, antibiotic sensitivity profiles cannot be relied upon to distinguish between persisting or relapsing infections as compared to reinfections in cats with CRF and multiple diagnoses of E coli UTI.
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
authors.forename: Thurid
authors.initials: T
authors.lastname: Freitag
authors.forename: Richard A
authors.initials: RA
authors.lastname: Squires
authors.forename: Jan
authors.initials: J
authors.lastname: Schmid
authors.forename: Jonathan
authors.initials: J
authors.lastname: Elliott
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Rycroft
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002371:Cat Diseases / Q000175:diagnosis / Q000382:microbiology*; D002415:Cats; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D005260:Female; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D008826:Microbial Sensitivity Tests; D012008:Recurrence; D014552:Urinary Tract Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*
chemical_list: D000900:Anti-Bacterial Agents