TABLE 2.
Distribution of erythromycin resistance genes among 54 erythromycin-resistant S. agalactiae isolates categorized according to erythromycin resistance phenotype and erythromycin and clindamycin MIC ranges
| Gene(s) | No. of strains | Pheno- typea | MIC range
|
|
|---|---|---|---|---|
| Erythromycin | Clindamycin | |||
| erm(B) | 13 | Cr | 4->64 | 4->64 |
| 3 | I | 2->64 | 0.03-0.2 | |
| erm(A) | 7 | Cr | 2->64 | 64->64 |
| 5 | I | 1-4 | 0.06-0.5 | |
| erm(B) + erm(A) | 9 | Cr | 2->64 | 32->64 |
| 9 | I | 2->64 | 0.06-0.2 | |
| mef(A) + erm(B) | 2 | I | 4->64 | 0.03-0.1 |
| mef(A) + erm(A) | 3 | M | 1-4 | 0.06-0.1 |
| 1 | I | 1 | 0.06 | |
| mef(A) | 2 | M | 4 | 0.06 |
a
Cr, cross-resistance; I, inducible; M, efflux.