TABLE 7.
Strain no. | Phenotype (resistance determinant)a | Selecting drug | Frequency of mutation at: |
||
---|---|---|---|---|---|
2× MIC | 4× MIC | 8× MIC | |||
1077 | Macrolide S | CEM-101 | <9.1 × 10−9 | <9.1 × 10−9 | <9.1 × 10−9 |
Azithromycin | 7.2 × 10−9 | <1.9 × 10−10 | <1.9 × 10−10 | ||
Clarithromycin | 1.1 × 10−9 | <1.2 × 10−10 | <1.2 × 10−10 | ||
Telithromycin | 1.1 × 10−9 | <5.5 × 10−10 | <5.5 × 10−10 | ||
Clindamycin | <3.8 × 10−10 | <3.8 × 10−10 | <3.8 × 10−10 | ||
24 | Macrolide R [erm(B)] | CEM-101 | 1.8 × 10−7 | <5.0 × 10−9 | <5.0 × 10−9 |
Azithromycin | NTb | NT | NT | ||
Clarithromycin | NT | NT | NT | ||
Telithromycin | 1.3 × 10−4 | 2.5 × 10−6 | 1.7 × 10−6 | ||
Clindamycin | NT | NT | NT | ||
3665 | Macrolide R [mef(A)] | CEM-101 | 6.8 × 10−7 | 1.4 × 10−7 | <4.5 × 10−10 |
Azithromycin | NT | NT | NT | ||
Clarithromycin | 5.0 × 10−7 | <5.0 × 10−10 | <5.0 × 10−10 | ||
Telithromycin | 7.5 × 10−9 | 2.5 × 10−9 | <2.5 × 10−10 | ||
Clindamycin | <2.4 × 10−10 | <2.4 × 10−10 | <2.4 × 10−10 | ||
1076 | Macrolide R [erm(B) mef(A)] | CEM-101 | <2.5 × 10−8 | 7.5 × 10−9 | 2.0 × 10−9 |
Azithromycin | NT | NT | NT | ||
Clarithromycin | NT | NT | NT | ||
Telithromycin | 6.5 × 10−6 | 9.7 × 10−6 | 4.8 × 10−6 | ||
Clindamycin | NT | NT | NT | ||
1635 | Macrolide R [erm(A)] | CEM-101 | 1.6 × 10−8 | <2.0 × 10−10 | <2.0 × 10−10 |
Azithromycin | <2.0 × 10−10 | <2.0 × 10−10 | <2.0 × 10−10 | ||
Clarithromycin | <3.1 × 10−9 | <3.1 × 10−9 | <3.1 × 10−9 | ||
Telithromycin | <2.7 × 10−9 | <2.7 × 10−9 | <2.7 × 10−9 | ||
Clindamycin | 7.3 × 10−7 | 5.5 × 10−7 | 5.6 × 10−7 | ||
2686 | Macrolide R (L4 mutation) | CEM-101 | <2.5 × 10−9 | <2.5 × 10−9 | <2.5 × 10−9 |
Azithromycin | NT | NT | NT | ||
Clarithromycin | NT | NT | NT | ||
Telithromycin | 2.2 × 10−5 | 2.2 × 10−9 | <1.1 × 10−9 | ||
Clindamycin | <1.2 × 10−9 | <1.2 × 10−9 | <1.2 × 10−9 | ||
7127 | Macrolide S (S20N in L4, A105V in L22) | CEM-101 | <2.0 × 10−10 | <2.0 × 10−10 | <2.0 × 10−10 |
Azithromycin | <2.0 × 10−10 | <2.0 × 10−10 | <2.0 × 10−10 | ||
Clarithromycin | <1.0 × 10−9 | <1.0 × 10−9 | <1.0 × 10−9 | ||
Telithromycin | <5.0 × 10−9 | <5.0 × 10−9 | <5.0 × 10−9 | ||
Clindamycin | <2.9 × 10−8 | <2.9 × 10−8 | <2.9 × 10−8 | ||
3009 | Macrolide R (23S rRNA mutation) | CEM-101 | <5.9 × 10−9 | <5.9 × 10−9 | <5.9 × 10−9 |
Azithromycin | NT | NT | NT | ||
Clarithromycin | NT | NT | NT | ||
Telithromycin | 3.8 × 10−7 | <1.5 × 10−10 | <1.5 × 10−10 | ||
Clindamycin | 1.7 × 10−4 | 7.3 × 10−9 | <1.2 × 10−10 |
S, susceptible; R, resistant.
NT, not tested.