Antimicrobial activity of ceftaroline-avibactam tested against clinical isolates collected from U.S. Medical Centers in 2010-2011.

Ceftaroline-avibactam and comparator agents were tested by the broth microdilution method against 20,089 isolates consecutively collected in 2010 and 2011 from 75 U.S. medical centers. Ceftaroline-avibactam was active against Enterobacteriaceae (4,908 strains; MIC90, 0.25 μg/ml; highest MIC, 4 μg/ml), including meropenem-nonsusceptible Klebsiella spp. and ceftazidime-nonsusceptible Enterobacter cloacae strains (MIC90, 1 μg/ml for both). Ceftaroline-avibactam was also active against ceftriaxone-nonsusceptible Streptococcus pneumoniae (MIC(90), 0.25 μg/ml) and methicillin-resistant Staphylococcus aureus (MIC(90), 1 μg/ml).