Table 2.
In vitro interaction of anidulafungin and fluconazole by the checkerboard and flow cytometry methods against 36 Candida speciesa
| Strain | Checkerboard MIC (μg/ml) |
FICI (interpretation) | Flow cytometry MIF |
SI (interpretation) | ||||
|---|---|---|---|---|---|---|---|---|
| AND | FLU | AND/FLU | AND | FLU | AND-FLU | |||
| C. albicans O189 | 0.25 | 32 | 0.06/0.06 | 0.24 (S) | 1.10 | 1.26 | 2.60 | 4.44 (S) |
| C. albicans O190 | 0.25 | 64 | 0.06/0.015 | 0.24 (S) | 0.48 | 0.48 | 1.24 | 5.13 (S) |
| C. albicans O195 | 0.015 | 4 | 0.015/0.06 | 1.02 (NI) | 2.70 | 1.62 | 2.34 | 2.31 (NI) |
| C. albicans O205 | 0.06 | 2 | 0.06/0.015 | 1.01 (NI) | 1.68 | 0.93 | 0.82 | 1.36 (NI) |
| C. albicans O207 | 0.015 | 4 | 0.015/0.06 | 1.02 (NI) | 2.30 | 1.74 | 1.55 | 1.57 (NI) |
| C. albicans O216 | 0.25 | 64 | 0.06/0.06 | 0.24 (S) | 4.77 | 3.16 | 7.72 | 4.06 (S) |
| C. albicans O223 | 0.25 | 1 | 0.06/0.06 | 0.30 (S) | 1.75 | 1.39 | 4.37 | 5.65 (S) |
| C. albicans O236 | 0.25 | 16 | 0.06/0.06 | 0.24 (S) | 1.10 | 1.03 | 2.17 | 4.08 (S) |
| C. albicans O237 | 0.25 | 64 | 0.06/0.06 | 0.24 (S) | 2.67 | 1.29 | 3.50 | 4.03 (S) |
| C. albicans O245 | 0.015 | 64 | 0.015/0.06 | 1 (NI) | 1.41 | 1.27 | 1.34 | 2.00 (NI) |
| C. albicans OL122 | 0.125 | 0.5 | 0.125/0.015 | 1.03 (NI) | 8.00 | 4.79 | 5.69 | 1.90 (NI) |
| C. albicans OL160 | 0.03 | 16 | 0.015/0.125 | 0.51 (NI) | 0.38 | 0.38 | 0.59 | 3.09 (NI) |
| C. albicans OL171 | 0.015 | 0.5 | 0.015/0.015 | 1.03 (NI) | 0.48 | 0.49 | 0.48 | 2.00 (NI) |
| C. albicans OL172 | 0.03 | 16 | 0.015/0.125 | 0.51 (NI) | 1.26 | 0.91 | 1.68 | 3.19 (NI) |
| C. albicans OL196 | 0.015 | 64 | 0.015/0.06 | 1 (NI) | 1.28 | 1.41 | 1.28 | 1.91 (NI) |
| C. albicans ATCC | 0.03 | 0.125 | 0.015/0.015 | 0.62 (NI) | 1.69 | 1.40 | 1.79 | 2.33 (NI) |
| C. glabrata O158 | 4 | 4 | 0.5/1 | 0.38 (S) | 7.93 | 1.01 | 8.90 | 9.93 (S) |
| C. glabrata O181 | 4 | 4 | 0.25/1 | 0.31 (S) | 2.48 | 0.51 | 2.83 | 6.72 (S) |
| C. glabrata O188 | 0.5 | 8 | 0.06/0.06 | 0.13 (S) | 3.77 | 2.81 | 7.15 | 4.44 (S) |
| C. glabrata O180 | 0.5 | 16 | 0.125/0.06 | 0.25 (S) | 0.46 | 1.02 | 1.30 | 4.09 (S) |
| C. glabrata O206 | 0.03 | 16 | 0.015/0.06 | 0.51 (NI) | 1.88 | 1.80 | 2.04 | 2.22 (NI) |
| C. glabrata OL149 | 0.25 | 16 | 0.06/0.06 | 0.24 (S) | 2.08 | 1.22 | 3.24 | 4.20 (S) |
| C. glabrata OL158 | 4 | 8 | 0.06/4 | 0.52 (NI) | 1.27 | 1.01 | 1.14 | 2.03 (NI) |
| C. glabrata OL163 | 0.25 | 16 | 0.06/0.06 | 0.24 (S) | 1.78 | 1.57 | 1.96 | 2.35 (NI) |
| C. glabrata OL164 | 0.25 | 8 | 0.06/0.015 | 0.24 (S) | 0.96 | 0.62 | 1.61 | 4.29 (S) |
| C. krusei OL16 | 0.25 | 64 | 0.125/0.06 | 0.51(NI) | 1.10 | 1.06 | 1.15 | 2.13 (NI) |
| C. parapsilosis Cpo41 | 8 | 0.125 | 0.06/0.5 | 4.01 (A) | 1.34 | 1.11 | 0.59 | 0.97 (A) |
| C. parapsilosis O136 | 4 | 2 | 0.25/2 | 1.06 (NI) | 1.64 | 0.91 | 0.92 | 1.57 (NI) |
| C. parapsilosis O246 | 2 | 0.5 | 0.25/0.25 | 0.625 (NI) | 1.53 | 1.72 | 1.66 | 2.05 (NI) |
| C. parapsilosis O56 | 4 | 0.5 | 0.5/0.25 | 0.625 (NI) | 2.33 | 4.06 | 3.07 | 2.07 (NI) |
| C. parapsilosis OL143 | 2 | 2 | 0.25/0.5 | 0.38 (S) | 3.37 | 4.37 | 4.96 | 2.61 (NI) |
| C. parapsilosis ATO16 | 4 | 0.25 | 0.5/0.06 | 0.37 (S) | 3.10 | 3.53 | 4.31 | 2.61 (NI) |
| C. parapsilosis OL144 | 2 | 2 | 0.5/1 | 0.75 (NI) | 1.95 | 1.18 | 1.94 | 2.65 (NI) |
| C. tropicalis OL193 | 0.015 | 2 | 0.015/0.06 | 1.03 (NI) | 1.12 | 1.68 | 1.53 | 2.27 (NI) |
| C. tropicalis OL202 | 0.015 | 2 | 0.015/0.06 | 1.03 (NI) | 0.47 | 0.75 | 0.46 | 1.60 (NI) |
| C. tropicalis OL295 | 0.25 | 2 | 0.06/0.06 | 0.27 (S) | 1.43 | 0.98 | 2.57 | 4.42 (S) |
a
S, synergism; A, antagonism; NI, no interaction; FICI, fractional inhibitory concentration index; MIF, mean intensity of fluorescence; SI, staining index. MIF was determined using 0.5× MIC of each drug. FICI = (MIC AND/FLU)/MIC AND + (MIC FLU/AND)/MIC FLU. SI = (MIF AND + FLU)/MIF AND + (MIF AND + FLU)/MIF FLU.