Table 3.
DCS sensitivity of E. coli CFT073 and K-12 gcvB mutant strains grown on LB agar
| Strain | Description | Avg zone of inhibitiona (mm) | MICb (μg/ml) |
|---|---|---|---|
| CFT073 | Wild type | 14.0 (±1.2) | 20 (±5) |
| WAM4326 | CFT073 gcvB | 13.6 (±0.7) | 40 (±5) |
| WAM4249 | CFT073 cycA | 13.8 (±0.8) | 20 (±5) |
| WAM4290 | CFT073 cycA/pACYC177 | 13.7 (±0.7) | 20 (±5) |
| WAM4291 | CFT073 cycA/pcycA | 13.7 (±0.7) | 20 (±5) |
| BW25113 | Wild type | 13.0 (±0.5) | 30 (±5) |
| WAM4372 | BW25113 gcvB | 12.5 (±0.5) | 40 (±5) |
| WAM4420 | BW25113 cycA | 12.9 (±0.2) | 30 (±5) |
| WAM4418 | BW25113 cycA/pACYC177 | 12.4 (±0.4) | 25 (±5) |
| WAM4419 | BW25113 cycA/pcycA | 12.4 (±0.2) | 30 (±5) |
| GS162 | Wild type | 13.8 (±0.4) | 15 (±5) |
| GS1148 | GS162 gcvB | 14.3 (±0.4) | 15 (±5) |
a
DCS sensitivity was determined by antibiotic disk diffusion assay. A 10-μl aliquot from a 24.5 mM solution of DCS was added to each disk. Each data point represents the average zone of growth inhibition and the resulting standard deviations from three experimental replicates.
b
Andrew's microdilution method was used to determine the DCS MIC for each strain (26). The MIC for each strain was determined in LB broth. The MIC was reported as the median from three experimental replicates performed for each strain.