TABLE 2.
MIC values for cell wall-targeting antibiotics
| Strain or population | MIC (μg/ml)a |
|||
|---|---|---|---|---|
| CHX | DAP range, median (P) | AMP | VAN | |
| E. faecium 410 | 4.9 | 2, 2 (NA) | 195 | 250 |
| Population A | 19.6 | 2–6, 3 (0.0085) | 390 | 500 |
| Population B | 19.6 | 3–4, 3.5 (0.0006) | 195 | 500 |
| DAP-A1 | 19.6 | 3–6, 4 (0.0043) | 195 | 500 |
| DAP-A2 | 19.6 | 3–6, 4 (0.0015) | 390 | 1,000 |
| DAP-B1 | 19.6 | 3–4, 3.5 (0.0006) | 195 | 1,000 |
| DAP-B2 | 19.6 | 3–4, 3.5 (0.0006) | 195 | 1,000 |
| PB301 (E. faecium 410 ΔefrEF) | 1.2 | 2–3, 2 (0.211) | ND | ND |
| PB302 (DAP-A2 ΔefrEF) | 2.4 | 2–4, 3 (0.00188) | ND | ND |
a
DAP MICs were determined independently either seven times (E. faecium 1,231,410 and population A) or six times (all other determinations). A one-tailed unpaired Student t test was used to assess the significance (P) of the difference in MIC versus E. faecium 1,231,410. E. faecium 410, E. faecium 1,231,410; AMP, ampicillin; VAN, vancomycin; NA, not applicable; ND, not determined.