TABLE 2.
Drug sensitivities of Schu S4 ΔtolC, ΔftlC, and ΔsilC mutant strains
| Compound | Concn, μg/disc | Zone of inhibition, mm (mean ± SD), for strain with indicated genotypea |
|||
|---|---|---|---|---|---|
| WT | ΔtolC | ΔftlC | ΔsilC | ||
| SDS | 188 | 6 ± 1 | 14 ± 2 | 13 ± 0 | 10 ± 0 |
| Streptomycin | 2.5 | 15 ± 1 | 15 ± 3 | 14 ± 2 | 17 ± 1 |
| Chloramphenicol | 1.25 | 10 ± 4 | 15 ± 2 | 14 ± 3 | 11 ± 4 |
| Erythromycin | 5 | 29 ± 1 | 39 ± 2 | 33 ± 1 | 29 ± 1 |
| Ampicillin | 2.5 | 6 ± 0 | 6 ± 0 | 6 ± 0 | 6 ± 0 |
| Polymyxin B | 100 | 6 ± 0 | 6 ± 0 | 6 ± 0 | 6 ± 0 |
| CCCP | 10 | 9 ± 0 | ND | ND | 13 ± 1 |
| Nalidixic acid | 5 | 20 ± 1 | ND | ND | 26 ± 1 |
| Silver nitrate | 500 | 6 ± 1 | ND | ND | 11 ± 1 |
| Hydrogen peroxide | 1.8 | 8 ± 1 | 8 ± 1 | 8 ± 1 | 8 ± 1 |
| 3.6 | 19 ± 0 | 19 ± 1 | 19 ± 1 | 19 ± 1 | |
| t-Butyl hydroperoxide | 9 | 8 ± 2 | 7 ± 1 | 8 ± 1 | 14 ± 2 |
| 18 | 8 ± 1 | 8 ± 1 | 8 ± 2 | 19 ± 1 | |
a
Zones of growth inhibition (including the 6-mm filter disc) are shown. Values shown in bold are significantly different from corresponding WT values by Student t test. ND, not determined.