TABLE 1.
Frequencies of the appearance of spontaneous mutants resistant to streptomycin and/or rifampin in M. smegmatisa
| Strain | Mutation frequency with drug | |
|---|---|---|
| Wild type | Str* | Rif* |
| mc26 | >2 × 10−4 | >2.4 × 10−5 |
| Strr mutant | Rif* | Rif + Str* |
| R43L | >4.5 × 10−5 | 9.0 × 10−7 |
| N43L | >2.5 × 10−5 | 4.2 × 10−8 |
| Rifr mutant | Str* | Str + Rif* |
| R526H | >2 × 10−3 | 2.5 × 10−7 |
| Y526H | >4 × 10−4 | 5.5 × 10−8 |
a
The frequencies of the appearance of resistant mutants are relative to the total CFU plated. Str, streptomycin; Rif, rifampin; ∗, selective medium contains the indicated drug.