Table 1.
Antimicrobial activities of HY-133 and oxacillin for 12 clinical wild type (WT) isolates compared with their clonally identical small-colony variants (SCVs).
| Antimicrobial Agent | Growth Phase | Phenotype (No. of Strains) | Median MIC (mg/L) 1 | Median MBC (mg/L) 1 | ||||
|---|---|---|---|---|---|---|---|---|
| 50% | 90% | Range | 50% | 90% | Range | |||
| HY-133 | Stationary growth 2 | WT (12) | 0.12 | 0.5 | 0.12–0.5 | 0.12 | 0.5 | 0.12–0.5 |
| SCV (12) | 0.25 | 0.5 | 0.12–0.5 | 0.25 | 0.5 | 0.12–0.5 | ||
| Logarithmic growth 3 | WT (12) | 0.25 | 0.5 | 0.25–0.5 | 0.25 | 0.5 | 0.25–0.5 | |
| SCV (12) | 0.12 | 0.5 | 0.12–0.5 | 0.12 | 0.5 | 0.12–0.5 | ||
| Oxacillin | Stationary growth 2 | WT (12) | 0.5 | 1 | 0.25–2 | 0.5 | 1 | 0.25–2 |
| SCV (12) | 0.25 | 1 | 0.25–1 | 0.25 | 1 | 0.25–2 | ||
| Logarithmic growth 3 | WT (12) | 0.5 | 1 | 0.25–1 | 0.5 | 1 | 0.25–2 | |
| SCV (12) | 0.25 | 0.5 | 0.12–1 | 0.25 | 1 | 0.25–1 | ||
1 50% and 90%, MIC and MBC for 50% and 90% of strains tested, respectively. 2 Determination of MIC and MBC with direct colony suspension method. 3 Determination of MIC and MBC from log phase after 3 h of incubation. MIC and MBC were performed in triplicate for each strain and growth phase, and the determined medians were used to calculate the given MIC50/90 and MBC50/90 values and ranges.