Ceftazidime-avibactam activity against multidrug-resistant Pseudomonas aeruginosa isolated in U.S. medical centers in 2012 and 2013.

Pseudomonas aeruginosa isolates (n = 3,902) from 75 U.S. medical centers were tested against ceftazidime-avibactam and comparator agents by the reference broth microdilution method. Overall, 96.9% of the strains were susceptible (MIC, ≤8 μg/ml) to ceftazidime-avibactam, while the rates of susceptibility for ceftazidime, meropenem, and piperacillin-tazobactam were 83.8, 81.9, and 78.5%, respectively. Multidrug-resistant and extensively drug-resistant phenotypes were observed in 14.9 and 8.7% of the strains, respectively, and 81.0 and 73.7% of the strains were susceptible to ceftazidime-avibactam, respectively.