Table 1.
Detection of GBS following 9-hour incubation in the presence of erythromycin and dilutions of clindamycin. Isolate A (noninducible resistance to clindamycin) compared with isolate B (inducible resistance capable). ++++ OD > 3.0. +++ OD 2.0–2.9. ++ OD 1.0–1.9. + OD 0.1–0.9. − OD 0–0.099.
| 107 bacteria/mL | 106 bacteria/mL | 105 bacteria/mL | 104 bacteria/mL | |||||
|---|---|---|---|---|---|---|---|---|
| Isolate A | Isolate B | Isolate A | Isolate B | Isolate A | Isolate B | Isolate A | Isolate B | |
| Clindamycin 0 μg/mL Erythromycin 1.0 μg/mL |
++++ | ++++ | ++++ | ++++ | ++++ | ++++ | ++++ | +++ |
|
| ||||||||
| Clindamycin 0.5 μg/mL Erythromycin 1.0 μg/mL |
− | ++++ | − | ++ | − | + | − | + |
|
| ||||||||
| Clindamycin 0.05 μg/mL Erythromycin 1.0 μg/mL |
− | ++++ | − | +++ | − | + | − | + |
|
| ||||||||
| Clindamycin 0.005 μg/mL Erythromycin 1.0 μg/mL |
− | ++++ | − | +++ | − | + | − | + |