TABLE 2.
Mutation frequency to rifampin resistance after UV irradiation and chronic exposure to the quinolone nalidixic acida
| Treatment | Avg ± SD |
||
|---|---|---|---|
| % Survival | Frequency (10−8) | Fold increase for L. pneumophila and E. colib | |
| UV (J/m2) | |||
| 0 | 100 | 4.1 ± 1.0 | 1 |
| 5 | 96 ± 21 | 10.8 ± 3.9 | 2.6 ± 1.1 (92) |
| 7.5 | 77 ± 22 | 14.9 ± 6.9 | 3.6 ± 1.8 (178) |
| 10 | 23 ± 13 | 30.1 ± 6.4 | 7.3 ± 2.9 (223) |
| Nalidixic acid (μg/ml) | |||
| 0 | 100 | 5.8 ± 1.0 | 1 |
| 0.16 | 27 ± 11 | 10.8 ± 3.1 | 1.9 ± 0.8 (ND) |
| 0.24 | 0.8 ± 0.7 | 14.6 ± 7.9 | 2.6 ± 1.6 (ND) |
a
Values are averages from three independent experiments (n = 3). ND, not determined.
b
The values for E. coli are given in parentheses.