In vitro activity of daptomycin against clinical isolates with reduced susceptibilities to linezolid and quinupristin/dalfopristin

An initiative was taken to determine the in vitro activity of daptomycin against 85 Gram-positive isolates with reduced susceptibilities to linezolid and quinupristin/dalfopristin. Daptomycin had potent activity against all strains, with a Staphylococcus spp. minimum inhibitory concentration (MIC) ≤2 μg/mL and an Enterococcus spp. MIC ≤8 μg/mL. Resistance to linezolid and quinupristin/dalfopristin appears to be independent of reduced susceptibility to daptomycin.