TABLE 3.
In vitro activity of TEL against E. faecalis isolates with ERY-specific resistant genes.
| Erythromycin resistance genes | No. (%) | TEL MIC (μg/mL) |
ERY MIC (μg/mL) |
|||||||||
| ≤0.5 | 1 | 2 | 4 | ≥8 | MIC50/MIC90 | ≤0.5 | 1–4 | ≥8 | MIC50/MIC90 | |||
| Total | 280 | 116 | 7 | 27 | 97 | 33 | 2/8 | 10 | 58 | 212 | >256/>256 | |
| ermA | + | 11 (3.9) | 1 | 0 | 0 | 6 | 4 | 4/8 | 0 | 0 | 11 | >256/>256 |
| − | 269 (96.1) | 115 | 7 | 27 | 91 | 29 | 2/8 | 10 | 58 | 201 | >256/>256 | |
| ermB | + | 188 (67.1) | 39 | 4 | 23 | 92 | 30 | 4/8 | 1 | 8 | 179 | >256/>256 |
| − | 92 (32.9) | 77 | 3 | 4 | 5 | 3 | 0.06/2 | 9 | 50 | 33 | 2/>256 | |
| ermC | + | 0 (0) | 0 | 0 | 0 | 0 | 0 | – | 0 | 0 | 0 | – |
| − | 280 (100) | 116 | 7 | 27 | 97 | 33 | 2/8 | 10 | 58 | 212 | >256/>256 | |
MIC, minimum inhibitory concentration; TEL, telithromycin; ERY, erythromycin; +, positive; −, negative; MIC50/MIC90, the MIC values for 50% or 90% of bacterial growth inhibition.