Antimicrobial susceptibility of 3931 organisms isolated from intensive care units in Canada: Canadian National Intensive Care Unit Study, 2005/2006

Abstract

We tested the in vitro activity of 15 antimicrobials against Gram-positive cocci and 12 antimicrobials against Gram-negative bacilli versus 3931 isolates (20 most common organisms) obtained between September 1, 2005, and June 30, 2006, from 19 intensive care units (ICUs) across Canada. The most active (based upon MIC only) agents against methicillin-resistant Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis were dalbavancin, daptomycin, linezolid, tigecycline, and vancomycin with MIC 90 (μg/mL) of 0.06 and ≤0.03, 0.25 and 0.12, 2 and 1, 0.5 and 0.5, and 1 and 2, respectively. The most active agents against vancomycin-resistant enterococci were daptomycin, linezolid, and tigecycline with MIC 90 (μg/mL) of 1, 4, and 0.12, respectively. The most active agents against Escherichia coli were amikacin, cefepime, meropenem, piperacillin/tazobactam, and tigecycline with MIC 90 (μg/mL) of 4, ≤1, ≤0.12, 8, and 0.5, respectively. The most active agents against extended-spectrum β-lactamase–producing E. coli were meropenem and tigecycline with MIC 90 (μg/mL) of ≤0.12 and 1, respectively. The most active agents against Pseudomonas aeruginosa were amikacin, cefepime, meropenem, and piperacillin/tazobactam with MIC 90 (μg/mL) of 16, 32, 16, and 64, respectively. The most active agents against Stenotrophomonas maltophilia were tigecycline and trimethoprim/sulfamethoxazole with MIC 90 (μg/mL) of 4 and 4, respectively. The most active agents against Acinetobacter baumannii were fluoroquinolones (e.g., levofloxacin), meropenem, and tigecycline with MIC 90 (μg/mL) of 0.5, 1, and 2, respectively. In conclusion, the most active agents versus Gram-positive cocci and Gram-negative bacilli obtained from Canadian ICUs were daptomycin, linezolid, tigecycline, dalbavancin and amikacin, cefepime, meropenem, piperacillin/tazobactam, and tigecycline (not P. aeruginosa), respectively.