Table 2.
Minimum inhibitory concentration (MIC)a (µg/mL) and minimum bactericidal concentration (MBC)b (µg/mL) of metabolic inhibitors combined with antimicrobials against Escherichia coli O157:H7 using an antimicrobial fixed broth dilution method
| Antimicrobials (µg/mL) | Combined with metabolic inhibitors (µg/mL) | ||||||
|---|---|---|---|---|---|---|---|
| Chloramphenicol | Nalidixic acid | Rifampicin | Penicillin | D-cycloserine | Streptomycin | Cerulenin | |
| (a) MIC | |||||||
| None | 1.56 | 25.00 | 12.50 | 25.00 | 50.00 | 12.50 | 125.00 |
| Ethanol (15,625) | 3.13 | 25.00 | 1.56 | 25.00 | 25.00 | 6.25 | 250.00 |
| EDTA (91) | 0.10 | 0.20 | 0.10 | 0.39 | 6.25 | 0.10 | 0.49 |
| Polymyxin B (2) | 1.56 | 25.00 | 0.39 | 25.00 | 25.00 | 12.50 | 500.00 |
| Thymol (250) | 0.78 | 12.50 | 3.13 | 12.50 | 6.25 | 1.56 | 250.00 |
| Acetic acid (625) | 3.13 | 25.00 | 6.25 | 25.00 | 25.00 | 12.50 | 250.00 |
| Citrus (19.5) | 0.39 | 6.25 | 1.56 | 25.00 | 25.00 | 12.50 | 250.00 |
| (b) MBC | |||||||
| Nonec | 6.25 | 50.00 | 25.00 | 100.00 | 100.00 | 50.00 | 500.00 |
| Ethanol (15,625) | 25.00 | 100.00 | > 100.00 | > 100.00 | 100.00 | 50.00 | 500.00 |
| EDTA (91) | 12.50 | 50.00 | 12.50 | 50.00 | 50.00 | 50.00 | 500.00 |
| Polymyxin B (2) | 12.50 | 50.00 | 0.78 | 100.00 | > 100.00 | 50.00 | > 500.00 |
| Thymol (250) | 6.25 | 50.00 | 100.00 | 100.00 | 50.00 | 100.00 | > 500.00 |
| Acetic acid (625) | 12.50 | 50.00 | 100.00 | 100.00 | 50.00 | 100.00 | > 500.00 |
| Citrus (19.5) | 6.25 | 50.00 | 50.00 | 100.00 | 100.00 | 100.00 | 500.00 |
aMIC was determined as the minimum concentration that resulted in < 0.4 optical density at 595 nm
bMBC was determined as the minimum concentration that resulted in < 0.1 optical density at 595 nm
cNone, TSB without metabolic inhibitor