Antimicrobial susceptibility of Pseudomonas aeruginosa isolates obtained from patients in Canadian hospitals: CANWARD 2008–2011

Broth microdilution (Clinical and Laboratory Standards Institute) was used to evaluate the antimicrobial susceptibility of 1549 Pseudomonas aeruginosa clinical isolates collected in Canada between January 2008 and October 2011. The percentage of isolates susceptible was as follows: amikacin 92.0%, ceftazidime 83.5%, ciprofloxacin 74.3%, colistin 93.4%, gentamicin 76.8%, meropenem 82.7%, and piperacillin–tazobactam 83.6%. Antimicrobial susceptibility did not change significantly between 2008 and 2011, with the exception of increasing susceptibility to gentamicin (P < 0.0001).