title: Changes in fluoroquinolone resistance over 5 years (CANWARD 2007-11) in bacterial pathogens isolated in Canadian hospitals.
abstract: OBJECTIVE
  The purpose of this study was to analyse Canadian national surveillance data, specifically fluoroquinolone resistance, from 2007 to 2011 inclusive, to determine trends in resistance over time and to assess correlations with patient demographic factors.
  
  
  METHODS
  All isolates of Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pneumoniae collected by the 10 sites that participated in the annual CANWARD surveillance studies in each of the 5 years were included in this analysis. A multifactorial logistic regression model was used to determine the variables with significant impact on fluoroquinolone resistance.
  
  
  RESULTS
  The proportion of E. coli isolates resistant to ciprofloxacin increased significantly (P = 0.0005) between 2007 (20.0%) and 2011 (29.2%), although similar increases were not seen in K. pneumoniae, E. cloacae, P. aeruginosa and S. pneumoniae (tested against levofloxacin) (P > 0.05). Among isolates of S. aureus, there was a significant decrease in ciprofloxacin resistance from 34.4% in 2007 to 24.6% in 2011 (P < 0.0001). Resistance to ciprofloxacin was a component of most multidrug-resistant (MDR) phenotypes for E. coli, K. pneumoniae, E. cloacae, P. aeruginosa and S. aureus.
  
  
  CONCLUSIONS
  A significant increase in the percentage of ciprofloxacin-resistant E. coli, primarily among urine isolates, and a significant decrease in the percentage of ciprofloxacin-resistant S. aureus occurred between 2007 and 2011. Notably, MDR isolates were frequently fluoroquinolone resistant for all organisms studied, except S. pneumoniae.
authors.affiliation: Department of Clinical Microbiology, Health Sciences Centre/Diagnostic Services of Manitoba, Winnipeg, Manitoba, Canada R3A 1R9. jkarlowsky@dsmanitoba.ca
authors.forename: James A
authors.initials: JA
authors.lastname: Karlowsky
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Adam
authors.forename: Marc
authors.initials: M
authors.lastname: Desjardins
authors.forename: Philippe R S
authors.initials: PR
authors.lastname: Lagacé-Wiens
authors.forename: Daryl J
authors.initials: DJ
authors.lastname: Hoban
authors.forename: George G
authors.initials: GG
authors.lastname: Zhanel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification; D001424:Bacterial Infections / Q000453:epidemiology / Q000266:history / Q000382:microbiology; D002170:Canada / Q000453:epidemiology; D002648:Child; D003428:Cross Infection / Q000453:epidemiology* / Q000266:history / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology*; D049674:History, 21st Century; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones