TABLE 4.
Superoxide resistance of strains carrying MarA, MarA mutations, or SoxS
| Plasmid | Strain no. | Resistance to the indicated superoxide-generating compounda |
|||
|---|---|---|---|---|---|
| Phenazine methosulfate |
Menadione |
||||
| MIC (μM) | Relative increase in MIC | MIC (mM) | Relative increase in MIC | ||
| Vector | M5390 | 12 | 0.5 | ||
| WT MarA | M5391 | 35 | 1.0 | 1.8 | 1.0 |
| MarA(E25R) | M5392 | 31 | 0.89 | 1.6 | 0.91 |
| MarA(E77A) | M5393 | 22 | 0.65 | 1.2 | 0.68 |
| MarA(L80A) | M5394 | 42 | 1.2 | 1.4 | 0.76 |
| MarA(E89A) | M5395 | 57 | 1.7 | 2.4 | 1.3 |
| MarA(Q91A) | M5396 | 35 | 1.0 | 0.9 | 0.49 |
| WT SoxS | M5397 | 55 | 1.6 | 3.5 | 2.0 |
a
The MIC of each chemical for each strain was estimated from gradient plates that were performed two times. To determine the relative increase, the MIC for each strain was divided by that of the strain carrying the WT MarA plasmid.