Daptomycin Activity against Uncommonly Isolated Streptococcal and Other Gram-Positive Species Groups

Abstract

ABSTRACTA total of 1,356 clinical isolates were tested against daptomycin by broth microdilution methods. Daptomycin was active against seven groups of viridans group streptococci (MIC50and MIC90values ranging from ≤0.06 and ≤0.06 μg/ml [Streptococcus bovisandStreptococcus dysgalactiae] to 0.5 and 1 μg/ml [Streptococcus mitis,Streptococcus oralis, andStreptococcus parasanguinis], respectively), beta-hemolytic streptococci serogroups C, F, and G (MIC50and MIC90, ≤0.06 to 0.25 and 0.12 to 0.25 μg/ml, respectively),Corynebacteriumspp. (MIC50and MIC90, ≤0.06 and 0.12 μg/ml, respectively), andMicrococcusspp. (MIC50and MIC90, ≤0.06 and 0.25 μg/ml, respectively).Listeria monocytogenesexhibited higher daptomycin MICs (MIC50and MIC90, 2 and 4 μg/ml, respectively) than other tested organisms.