TABLE 3.
Frequency of spontaneous and oxidant-induced mutations
| B. fragilis strain | Frequency of mutations (no. of fusidic acid-resistant colonies/109 cells plated)a
|
|||
|---|---|---|---|---|
| Spontaneous (control) | Induced by:
|
|||
| No addition | 50 μM TBHP | 50 μM CHP | ||
| 638R | 1.1 | 1.5 | 2.1 | 4.2 |
| IB260 (katB) | 1.0 | 4.2 | 5.2 | 15 |
| IB274 (ahpCF) | 4.8 | 5.2 | 68 | NDb |
| IB276 (ahpF) | 6.8 | 7.4 | 13.2 | 192 |
| IB281 (ahpCF katB) | 8.1 | 8.6 | 19.0 | 199 |
a
Average of two determinations. TBHP, t-butyl hydroperoxide; CHP, cumene hydroperoxide.
b
ND, not determined due to bacterial cell lysis.