Table 2. Synergistic activity of simvastatin, pyrithione zinc, antimycin A, CCCP and sodium azide with miconazole against C. albicans biofilms.
| Concentration compound (μM) | BEC50 miconazole (μM)a | Fold changeb | FICIc |
|---|---|---|---|
| Simvastatin | |||
| 500 | 14 | 5.6 | 0.49 |
| 250 | 30 | 2.6 | 0.54 |
| 125 | 38 | 2.1 | 0.57 |
| 62.5 | 44 | 1.8 | 0.60 |
| 0 | 78 | 1.0 | NA |
| Pyrithione zinc | |||
| 20 | 20 | 4.2 | 0.31 |
| 10 | 19 | 4.4 | 0.26 |
| 5 | 24 | 3.5 | 0.30 |
| 2.5 | 52 | 1.6 | 0.63 |
| 0 | 84 | 1.0 | NA |
| Antimycin A | |||
| 25 | 6.4 | 12.7 | 0.12 |
| 12.5 | 7.5 | 10.8 | 0.11 |
| 6.25 | 9.9 | 8.2 | 0.13 |
| 3.125 | 7.4 | 10.9 | 0.10 |
| 0 | 81 | 1.0 | NA |
| CCCP | |||
| 62.5 | 7.7 | 13.6 | 0.93 |
| 31.25 | 18 | 5.8 | 0.60 |
| 15.625 | 27 | 3.9 | 0.47 |
| 7.8125 | 62 | 1.7 | 0.70 |
| 0 | 105 | 1.0 | NA |
| Sodium azide | |||
| 5,000 | 8.8 | 6.8 | 0.73 |
| 2,500 | 16 | 3.8 | 0.56 |
| 1,250 | 22 | 2.7 | 0.51 |
| 625 | 25 | 2.4 | 0.49 |
| 0 | 64 | 1.0 | NA |
The BEC50 values are the mean ± SEM of at least five (n = 5) independent biological replicates (each consisting of three repeats). FICI values indicating a synergistic interaction are printed in bold.
aBEC50 = Biofilm eradication concentration resulting in 50% remaining biofilm metabolic activity, calculated using nonlinear regression. The BEC50 value of simvastatin, pyrithione zinc, antimycin A, CCCP and sodium azide is 1.6 mM, 275 μM, 570 μM, 73 μM and 8.6 mM, respectively.
bFold change = fold increase of biofilm activity of miconazole due to the combination, calculated as (BEC50 of miconazole alone)/(BEC50 of miconazole in combination).
cFICI = Fractional inhibitory concentration index, NA = Not Applicable.