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:
|
||||||||
|---|---|---|---|---|---|---|---|---|---|
| ≤0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | >16 | |
| MIC | |||||||||
| Daptomycin | |||||||||
| MRSA-WT (102)a | 2 (2.0) | 41 (42.2) | 56b (97.1) | 3 (100.0) | 0 | 0 | 0 | 0 | 0 |
| hVISA (88) | 0 | 2 (2.3) | 52 (61.4) | 34 (100.0) | 0 | 0 | 0 | 0 | 0 |
| VISA (17) | 0 | 0 | 2 (11.8) | 7 (52.9) | 7 (94.1) | 1 (100.0) | 0 | 0 | 0 |
| Vancomycin | |||||||||
| MRSA-WT (102)a | −c | − | 9 (8.8) | 82 (89.2) | 11 (100.0) | 0 | 0 | 0 | 0 |
| hVISA (88) | − | − | 0 (0.0) | 9 (10.2) | 61 (79.5) | 18 (100.0) | 0 | 0 | 0 |
| VISA (17) | − | − | 0 (0.0) | 0 (0.0) | 0 (0.0) | 11 (64.7) | 6 (100.0) | 0 | 0 |
| MBC | |||||||||
| Daptomycin | |||||||||
| MRSA-WT (102)a | 0 | 29 (28.4) | 65 (92.2) | 7 (99.0) | 1 (100.0) | 0 | 0 | 0 | 0 |
| hVISA (88) | 0 | 2 (2.3) | 35 (40.9) | 49 (97.7) | 2 (100.0) | 0 | 0 | 0 | 0 |
| VISA (17) | 0 | 0 | 2 (11.8) | 4 (35.3) | 8 (82.4) | 3 (100.0) | 0 | 0 | 0 |
| Vancomycin | |||||||||
| MRSA-WT (102)a | − | − | 2 (2.0) | 38 (39.2) | 23 (61.8) | 9 (70.6) | 15 (85.3) | 4 (89.2) | 11 (100.0) |
| hVISA (88) | − | − | 0 | 3 (3.4) | 9 (14.9) | 5 (19.3) | 3 (22.7) | 7 (30.7) | 61 (100.0) |
| VISA (17) | − | − | 0 | 0 | 0 | 0 | 0 | 0 | 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.