TABLE 1.

MIC and MBC results for daptomycin and vancomycin

Antimicrobial agent/organism (total no. of isolates)No. of isolates (cumulative %) at MIC/MBC (μg/ml) of:
≤0.120.250.5124816>16
MIC
    Daptomycin
        MRSA-WT (102)a2 (2.0)41 (42.2) 56 b (97.1)3 (100.0)00000
        hVISA (88)02 (2.3) 52 (61.4)34 (100.0)00000
        VISA (17)002 (11.8) 7 (52.9) 7 (94.1)1 (100.0)000
    Vancomycin
        MRSA-WT (102)ac9 (8.8) 82 (89.2)11 (100.0)0000
        hVISA (88)0 (0.0)9 (10.2) 61 (79.5)18 (100.0)000
        VISA (17)0 (0.0)0 (0.0)0 (0.0) 11 (64.7)6 (100.0)00
MBC
    Daptomycin
        MRSA-WT (102)a029 (28.4) 65 (92.2)7 (99.0)1 (100.0)0000
        hVISA (88)02 (2.3)35 (40.9) 49 (97.7)2 (100.0)0000
        VISA (17)002 (11.8)4 (35.3) 8 (82.4)3 (100.0)000
    Vancomycin
        MRSA-WT (102)a2 (2.0) 38 (39.2)23 (61.8)9 (70.6)15 (85.3)4 (89.2)11 (100.0)
        hVISA (88)03 (3.4)9 (14.9)5 (19.3)3 (22.7)7 (30.7) 61 (100.0)
        VISA (17)000000 17 (100.0)
  • a Clinical MRSA isolate with vancomycin MIC of ≤2 μg/ml (homogeneous populations) collected from medical centers worldwide in 2003.

  • b The underlined numbers are modal values.

  • c —, dilution not tested.