TABLE 2.
Effect of preincubation with clarithromycin (0.125 μg/ml) on susceptibility of M. smegmatis mc2155 to a range of antimicrobials
| Initial phenotypea | Preincubation medium (time [h]) | MIC (μg/ml)b
|
|||||
|---|---|---|---|---|---|---|---|
| AMK | AZM | CIP | CLR | EMB | RBT | ||
| Susceptible | Medium alone (2) | 1 | 32 | 0.25 | 2 | 1 | 1 |
| Clarithromycin (2) | 1 | 256 | 0.5 | 32 | 1 | 1 | |
| Resistant | Medium alone (18) | 1 | ND | 0.5 | 2 | 1 | 1 |
| Clarithromycin (18) | 1 | ND | 0.5 | >64 | 1 | 1 | |
a
Susceptible organisms were maintained in the absence of antimicrobial agent. Resistant organisms were harvested from the wells of a previous susceptibility assay containing 16 μg of clarithromycin per ml.
b
AMK, amikacin; AZM, azithromycin; CIP, ciprofloxacin; CLR, clarithromycin; EMB, ethambutol; RBT, rifabutin; ND, not determined.