Table 4.
Results of serial passaging studies
| Straina | Antibiotic | MIC (μg/ml) |
MIC increase (fold) | |
|---|---|---|---|---|
| Initial | After 15 passages | |||
| S. aureus ATCC 19636 (MSSA) | MX-2401 | 1 | 8 | 8 |
| Daptomycin | 0.5 | 2 | 4 | |
| Vancomycin | 1 | 2 | 2 | |
| Fusidic acid | 0.25 | 0.5 | 2 | |
| S. aureus ATCC 29213 (MSSA) | MX-2401 | 2 | 16 | 8 |
| Daptomycin | 1 | 2 | 2 | |
| Vancomycin | NAb | NA | NA | |
| Fusidic acid | NA | NA | NA | |
| S. aureus ATCC 43300 (MRSA) | MX-2401 | 1 | 8 | 8 |
| Daptomycin | 0.25 | 4 | 16 | |
| Vancomycin | 0.5 | 2 | 4 | |
| Fusidic acid | 0.25 | 16 | 64 | |
| E. faecium ATCC 51559 (VRE) | MX-2401 | 2 | 8 | 4 |
| Daptomycin | 0.5 | 4 | 8 | |
| Vancomycin | >32 | >32 | NA | |
| Fusidic acid | 4 | >32 | >8 | |
| E. faecalis ATCC 29212 (VSE) | MX-2401c | 4 | 16–32 | 4–8 |
| Daptomycinc | 1–4 | 8 | 2–8 | |
| Vancomycin | 2 | 4 | 2 | |
| Fusidic acid | 4 | >32 | >8 | |
a
MRSA, methicillin-resistant S. aureus; MSSA, methicillin-sensitive S. aureus; VRE, vancomycin-resistant enterococci; VSE, vancomycin-sensitive enterococci.
b
NA, not available.
c
Results of two experiments are shown.