202. Antimicrobial Susceptibility of Pseudomonas aeruginosa Isolates Obtained from Patients in Canadian Hospitals: CANWARD 2007-2010
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Handouts
  • Walkty Pseudo IDSA2011_Aug29.pdf (287.6 kB)
  • Background:  Pseudomonas aeruginosa is an important nosocomial pathogen.  The purpose of this study was to evaluate the antimicrobial susceptibility profile of P. aeruginosa clinical isolates obtained from patients in Canadian hospitals.

    Methods:  From January 2007 through November 2010, tertiary-care centres from across Canada submitted pathogens from patients attending hospital clinics, emergency rooms (ERs), medical and surgical wards, and intensive care units (ICUs).  Annually, each centre was asked to submit pathogens (consecutive, one per patient/infection site) from blood, respiratory, urine, and wound/IV infections.  Susceptibility testing was performed using CLSI broth microdilution.

    Results:  1851 P. aeruginosa isolates were obtained as a part of CANWARD [632 in 2007, 373 in 2008, 470 in 2009, 376 in 2010; specimen source: 59% respiratory, 23% blood, 12% wound, 6% urine; ward type: 32% medical, 26% clinics, 20% ICUs, 14% ERs, 8% surgical].  The percentage of isolates susceptible to common antipseudomonal antimicrobials was: amikacin 89%, ciprofloxacin 71%, ceftazidime 83% (1217 isolates tested), colistin 93% (1355 isolates tested), gentamicin 69%, meropenem 89%, piperacillin-tazobactam 92%.  Susceptibility to these antimicrobials did not change significantly between 2008 and 2010 (p > 0.05), with the exception of ceftazidime which declined from 88% (2008) to 79% (2010) (p = 0.001).  One-hundred and sixty-four isolates (9%) were multidrug-resistant (MDR = resistant to at least 3 different antimicrobial classes).  MDR isolates were less commonly obtained from patients in the ER and from a bloodstream source (p < 0.05).  Eighty-nine percent of MDR isolates remained fully susceptible to colistin.

    Conclusion:  Susceptibility of P. aeruginosa clinical isolates to most common antipseudomonal antimicrobials has remained relatively stable in Canada over the past 3 years.  The majority of MDR isolates (89%) retain susceptibility to colistin.

     


    Subject Category: A. Antimicrobial agents and Resistance

    Andrew Walkty, MD1, Melanie Baxter, MSc1, Heather J. Adam, PhD2, Kim Nichol, MSc1, James Karlowsky, PhD1, Daryl J. Hoban, PhD1 and George G. Zhanel, PhD1, (1)University of Manitoba, Winnipeg, MB, Canada, (2)Department of Clinical Microbiology, Health Sciences Centre, Winnipeg, MB, Canada

    Disclosures:

    A. Walkty, None

    M. Baxter, None

    H. J. Adam, None

    K. Nichol, None

    J. Karlowsky, None

    D. J. Hoban, Abbott Laboratories Ltd: Research Relationship, Research support
    Astellas Pharma Canada Inc: Research Relationship, Research support
    Bayer Schering Pharma AG: Research Relationship, Research support
    Merck Frosst Canada Ltd.: Research Relationship, Research support
    Pfizer Canada Inc.: Research Relationship, Research support
    Sepracor Pharmaceuticals Inc.: Research Relationship, Research support
    The Medicines Company: Research Relationship, Research support

    G. G. Zhanel, Abbott Laboratories Ltd.: Research Relationship, Research support
    Astellas Pharma Canada Inc.: Research Relationship, Research support
    Bayer Shcering Pharma AG: Research Relationship, Research support
    Merck Frosst Canada Ltd.: Research Relationship, Research support
    Pfizer Canada Inc: Research Relationship, Research support
    Sepracor Pharmaceuticals Inc.: Research Relationship, Research support
    The Medicines Company: Research Relationship, Research support

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