TABLE 4.
Culture variable effects on S. aureus NCTC 8325 susceptibility to thiram, disulfiram, and diethyldithiocarbamate
| Variable(s) | MIC (μg/ml)a |
||||
|---|---|---|---|---|---|
| THM | DSF | DDTC | OXA | VAN | |
| 4.0 × 106 CFU/ml, 20 h | 8 | 16 | 64 | ≤0.5 | 1 |
| 4.0 × 106 CFU/ml, 24 h | 8 | 32 | 64 | ≤0.5 | 1 |
| 4.0 × 106 CFU/ml, 48 h | 32 | 64 | >64 | ≤0.5 | 2 |
| 3.3 × 108 CFU/ml, 24 h | 32 | 64 | >64 | ≤0.5 | 2 |
| 3.3 × 108 CFU/ml, 48 h | 64 | >64 | >64 | ≤0.5 | 4 |
| 5% CO2, 20 h | 8 | 16 | >64 | ≤0.5 | 1 |
| 5% CO2, 48 h | 16 | 64 | >64 | ≤0.5 | 1 |
| pH 5 | 2 | 4 | 32 | ≤0.5 | ≤0.5 |
| pH 6 | 8 | 16 | 64 | ≤0.5 | 1 |
| pH 7.4 | 8 | 16 | 64 | ≤0.5 | 1 |
| Serum, 5% (vol/vol) | 16 | 16 | >64 | ≤0.5 | 1 |
| Serum, 10% (vol/vol) | 16 | 16 | >64 | ≤0.5 | 1 |
| Albumin, 0.03% (vol/vol) | 16 | 16 | >64 | ≤0.5 | 1 |
| Glutathione, 100 μM | 16 | 32 | >64 | ≤0.5 | 1 |
| Thymidine, 100 μg/ml | 8 | 16 | 32 | ≤0.5 | 1 |
| Vitamin C, 20 μM | 8 | 16 | 64 | ≤0.5 | 1 |
| Vitamin E, 100 μM | 8 | 32 | 64 | ≤0.5 | 1 |
| Vitamin K3, 1 μg/ml | 8 | 16 | 32 | ≤0.5 | 1 |
| Tween 20, 0.1% (vol/vol) | 8 | 16 | >64 | ≤0.5 | 1 |
| Tween 80, 0.1% (vol/vol) | 16 | 32 | >64 | ≤0.5 | 1 |
| Oleic acid, 0.02% (vol/vol) | 8 | 16 | 64 | ≤0.5 | 2 |
a
Unless otherwise indicated, cultures were incubated at 37°C for 20 h in CAHMB. Susceptibility testing was performed by the broth microdilution method in 96-well plates using a 1:100 dilution of a 0.5 McFarland adjusted culture, and MIC values were recorded at 20 h.