Table 1.
Macrolide resistance phenotypes, erythromycin resistance genes and MIC50/90 values among 35 erythromycin-resistant S. pneumoniae isolates
| MIC range (mg/L) |
MIC 50/90 (mg/L) |
Resistance genes |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Phenotype | No. of strains (%) | Erythromycin | Clindamycin | Penicillin | Erythromycin | Clindamycin | Penicillin | ermB | mefA |
| cMLSB | 26 (73) | 64–≥128 | ≥32 | ≤0.03–4 | ≥128/≥128 | ≥32/≥32 | 1/2 | 26 | 7 |
| iMLSB | 3 (9) | 64–≥128 | ≤0.03–0.06 | 0.03–0.25 | ND | ND | ND | 3 | 0 |
| M | 6 (18) | 1–4 | ≤0.03 | ≤0.03–4 | ND | ND | ND | 0 5* | |
*
One strain in M phenotype was not include resistance genes. ND: not determined.