TABLE 7.
Induction of inducibly expressed erm genes after incubation with subinhibitory concentrations of erythromycin, telithromycin, and compound 19a
| Strain | Inducer | Inducer concn (μg/ml) | Inoculum size (no. of CFU/ml) | MIC (μg/ml) |
|||||
|---|---|---|---|---|---|---|---|---|---|
| AZM | ERY | CLI | CIP | TEL | Compound 19 | ||||
| S. aureus B 0949 erm(C) iMLSb | 1.3E+06 | >256 | >256 | 0.06 | 0.25 | 0.25 | 0.5 | ||
| ERY | 1 | 1.4E+05 | >256 | >256 | >8 | 0.25 | >8 | 8 | |
| ERY | 0.1 | 1.0E+06 | >256 | >256 | >8 | 0.25 | >8 | 4 | |
| ERY | 0.01 | 1.4E+06 | >256 | >256 | >8 | 0.25 | >8 | 4 | |
| TEL | 0.01 | 9.0E+05 | >256 | >256 | 0.125 | 0.25 | 0.125 | 0.25 | |
| 19 | 0.1 | 1.4E+05 | >256 | >256 | 0.06 | 0.25 | 0.25 | 0.25 | |
| 5.0E+05 | >256 | >256 | 0.25 | 1 | 8 | 0.03 | |||
| S. pyogenes B 0895 erm(B) iMLSb-A | ERY | 0.1 | 1.0E+05 | >256 | >256 | >8 | 1 | >32 | 1 |
| ERY | 0.01 | 8.0E+05 | >256 | >256 | >8 | 1 | >32 | 1 | |
| ERY | 0.001 | 8.0E+05 | >256 | >256 | >8 | 1 | >32 | 1 | |
| TEL | 0.1 | 8.0E+04 | >256 | >256 | >8 | 1 | >32 | 0.5 | |
| TEL | 0.01 | 2.0E+05 | >256 | >256 | >8 | 1 | 4 | 0.03 | |
| 19 | 0.001 | 1.5E+06 | >256 | >256 | 0.125 | 1 | 8 | ≤0.015 | |
a
AZM, azithromycin; ERY, erythromycin; CLI, clindamycin; CIP, ciprofloxacin; TEL, telithromycin.