TABLE 2.
Macrolide resistance mechanisms and MIC data for erythromycin, azithromycin, spiramycin, telithromycin, and clindamycin
| Mechanism (no. of isolates) | MIC (μg/ml)
|
||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Erythromycin
|
Azithromycin
|
Spiramycin
|
Telithromycin
|
Clindamycin
|
|||||||||||
| Range | 50% | 90% | Range | 50% | 90% | Range | 50% | 90% | Range | 50% | 90% | Range | 50% | 90% | |
| mef(E) (95) | 0.5->128 | 8 | 64 | 1->128 | 32 | 128 | 0.125-1 | 1 | 1 | 0.031-2 | 0.5 | 1 | 0.031-0.25 | 0.125 | 0.25 |
| mef(A) (12) | 16-64 | 32 | 64 | 32->128 | 32 | 128 | 1 | 1 | 1 | 0.125-0.5 | 0.5 | 0.5 | 0.125-0.25 | 0.125 | 0.125 |
| erm(B) (90) | 2->128 | >128 | >128 | 2->128 | >128 | >128 | 1->128 | >128 | >128 | 0.008-8 | 0.25 | 2 | 0.125->128 | >128 | >128 |
| erm(B) + mef(E) (5) | >128 | >128 | >128 | 0.063-2 | 2 | >128 | |||||||||
| erm(A) (1) | >128 | >128 | >128 | 0.25 | >128 | ||||||||||
| Mutation only (14)a | 0.25->128 | 8 | >128 | 4->128 | 32 | >128 | 0.5->128 | 32 | >128 | 0.016-0.25 | 0.031 | 0.125 | 0.063->128 | 2 | >128 |
a
The individual genotypes and phenotypes of mutated isolates are presented in Table 1.