Table 1.
Interaction of isavuconazole with colistin against common Candida species by checkerboard and interpretation by fractional inhibitory concentration index and response surface analysis.
| Species | Collection number | Checkerboard MICs (µg/ml) | Response surface analysis | |||||
|---|---|---|---|---|---|---|---|---|
| ISA | COL | ISA/COL | FICI | INTPN | ΣSYN-ANT (ΣSYN; ΣANT) | INTPN | ||
| Candida albicans | V2105126 | 0.002 | 128 | 0.001/16 | 0.625 | IND | −0.76 (21.00; −21.76) | IND |
| C. albicans | N2101578 | 0.0005 | 128 | 0.001/64 | 0.75 | IND | −26.21 (15.38; −41.59) | IND |
| C. albicans | V2105568 | 0.002 | 128 | 0.00006/64 | 0.625 | IND | 30.84 (36.97; −6.13) | IND |
| C. albicans | N2101577 | 0.002 | 128 | 0.001/64 | 1 | IND | 13.88 (29.36; −15.48) | IND |
| C. albicans | V2105825iso3 | 0.002 | 128 | 0.001/32 | 0.75 | IND | 31.53 (33.87; −2.34) | IND |
| C. albicans | ATCC 14053 | 0.002 | 128 | 0.0002/64 | 0.625 | IND | −18.30 (22.32; −40.62) | IND |
| C. albicans | V2105529 | 0.002 | 128 | 0.125/32 | 0.75 | IND | 5.75 (19.05; −13.30) | IND |
| C. albicans | V2106139 | 0.004 | 128 | 0.125/2 | 0.5156 | IND | 22.27 (28.42: −6.15) | IND |
| C. albicans | V2106041 | 0.002 | 64 | 0.06/1 | 0.5156 | IND | −0.48 (29.70; −0.48) | IND |
| C. albicans | V2106305 | 0.004 | 128 | 0.03/16 | 0.625 | IND | −3.57 (21.74; −25.31) | IND |
| Candida glabrata | V2105272 | 0.5 | 128 | 0.125/2 | 0.2656 | SYN | 39.63 (41.86; −2.23) | IND |
| C. glabrata | V2105282 | 0.5 | 128 | 0.125/8 | 0.3125 | SYN | 51.39 (51.73; −0.34) | IND |
| C. glabrata | N2101711 | 0.125 | 128 | 0.06/2 | 0.5156 | IND | 25.15 (31.05: −5.90) | IND |
| C. glabrata | V2105636 | 0.125 | 128 | 0.003/16 | 0.375 | SYN | 12.57 (25.00; −12.43) | IND |
| C. glabrata | DSM 70614 | 0.125 | 128 | 0.008/32 | 0.3125 | SYN | 33.03 (41.54; −8.51) | IND |
| C. glabrata | U2105834 | 0.125 | 128 | 0.03/16 | 0.375 | SYN | 52.37 (53.11; −0.74) | IND |
| C. glabrata | V2105576 | 0.125 | 128 | 0.03/32 | 0.5 | SYN | 33.35 (38.12; −4.77) | IND |
| C. glabrata | N2102530 | 0.125 | 128 | 0.03/8 | 0.3125 | SYN | 43.61 (47.42; −3.81) | IND |
| C. glabrata | U2106503 | 0.125 | 128 | 0.03/8 | 0.3125 | SYN | 52.90 (53.27; −0.37) | IND |
| C. glabrata | U2106602 | 0.25 | 64 | 0.03/8 | 0.25 | SYN | 60.21 (65.28; −5.07) | SYN |
| Candida krusei | V2105825iso4 | 0.125 | 64 | 0.016/16 | 0.375 | SYN | 37.13 (48.62; −11.49) | IND |
| C. krusei | V2105866 | 0.125 | 64 | 0.016/16 | 0.375 | SYN | 62.16 (71.23; −9.07) | SYN |
| C. krusei | V2106177 | 0.25 | 64 | 0.06/16 | 0.5 | SYN | 75.43 (77.34; −1.91) | SYN |
| C. krusei | V2105920 | 0.25 | 64 | 0.06/16 | 0.5 | SYN | 122.67 (123.03; −0.36) | SYN |
| C. krusei | ATCC 6258 | 0.03 | 16 | 0.016/2 | 0.625 | IND | 13.01 (23.66; −10.65) | IND |
| C. krusei | N2102290 | 0.125 | 128 | 0.03/32 | 0.5 | SYN | 12.20 (28.93; 16.73) | IND |
| C. krusei | N2102435 | 0.125 | 64 | 0.004/16 | 0.2813 | SYN | 90.28 (92.24; −1.96) | SYN |
| C. krusei | U2106649 | 0.125 | 64 | 0.03/16 | 0.5 | SYN | 53.12 (55.80; −2.68) | IND |
| C. krusei | U2106778 | 0.125 | 64 | 0.03/2 | 0.5313 | IND | 14.33 (54.69; −40.36) | IND |
| C. krusei | V2108462iso101 | 0.25 | 32 | 0.03/8 | 0.5 | IND | 76.01 (76.09; −0.08) | SYN |
| Candida parapsilosis | V2105056 | 0.016 | 128 | 0.004/4 | 0.2813 | SYN | 43.71 (46.49; −2.78 | IND |
| C. parapsilosis | V2105223 | 0.016 | 128 | 0.004/1 | 0.2578 | SYN | 55.49 (65.12; −9.63) | IND |
| C. parapsilosis | B2107379 | 0.008 | 128 | 0.004/1 | 0.5078 | IND | 28.56 (29.81; −1.25) | IND |
| C. parapsilosis | ATCC 22019 | 0.03 | 64 | 0.008/8 | 0.375 | SYN | 7.38 (36.44; −29.06) | IND |
| C. parapsilosis | U2106978 | 0.016 | 128 | 0.008/1 | 0.5078 | IND | −14.61 (4.96; −19.57) | IND |
| C. parapsilosis | V2111362 | 0.008 | 128 | 0.004/2 | 0.5156 | IND | 38.05 (38.26; −0.21) | IND |
| C. parapsilosis | V2111422 | 0.004 | 64 | 0.002/2 | 0.5313 | IND | 22.59 (32.49; −9.90) | IND |
| C. parapsilosis | V2113147 | 0.008 | 128 | 0.004/64 | 1 | IND | −48.79 (8.98; −57.77) | IND |
| C. parapsilosis | V2113210 | 0.016 | 128 | 0.008/2 | 0.5156 | IND | 34.82 (43.88; −9.06) | IND |
| Candida tropicalis | V2105128 | 0.008 | 16 | 0.002/16 | 0.5 | SYN | 12.31 (33.75, −21.44) | IND |
| C. tropicalis | V2105245 | 0.008 | 16 | 0.002/16 | 0.5 | SYN | 23.42 (29.74; −6.32) | IND |
| C. tropicalis | V2105598 | 0.008 | 16 | 0.002/16 | 0.5 | SYN | 88.36 (88.39; −0.03) | SYN |
| C. tropicalis | B1907975 | 0.008 | 32 | 0.002/32 | 0.375 | SYN | 48.49 (59.88; −11.39) | IND |
| C. tropicalis | V2106298 | 0.008 | 32 | 0.002/32 | 0.5 | SYN | 48.95 (74.91; −25.96) | IND |
| C. tropicalis | U2106694 | 0.06 | 16 | 0.016/4 | 0.5 | SYN | 47.39 (47.62; −0.23) | IND |
| C. tropicalis | U2107090 | 0.06 | 32 | 0.016/4 | 0.375 | SYN | 66.67 (67.74; −1.06) | SYN |
| C. tropicalis | N2102715 | 0.008 | 16 | 0.002/2 | 0.375 | SYN | 75.98 (76.32; −0.34) | SYN |
| C. tropicalis | V2108236 | 0.008 | 16 | 0.002/4 | 0.5 | SYN | 65.93 (66.36; −0.43) | SNY |
| C. tropicalis | V2108424 | 0.008 | 16 | 0.0005/8 | 0.5625 | IND | 65.12 (66.25; −1.13) | SYN |
| Candida kefyr | V2105566 | 0.004 | 32 | 0.002/2 | 0.5625 | IND | 5.84 (30.25; −24.41) | IND |
| C. kefyr | V2106126 | 0.004 | 64 | 0.001/16 | 0.5 | SYN | 100.81 (100.81; −0.0) | SYN |
| C. kefyr | N2101899 | 0.001 | 16 | 0.0005/4 | 0.75 | IND | −0.91 (9.10; −10.01) | IND |
| C. kefyr | N2102541 | 0.002 | 8 | 0.001/8 | 0.5625 | IND | 69.86 (70.78; −0.92) | SYN |
| C. kefyr | V2107273 | 0.06 | 4 | 0.016/4 | 0.5 | SYN | 15.56 (35.50; −19.94) | IND |
| C. kefyr | V2107293 | 0.008 | 4 | 0.002/4 | 0.5 | SYN | 81.29 (83.81; −2.52) | SYN |
| C. kefyr | V2107534 | 0.001 | 1 | 0.0005/1 | 0.5625 | IND | 59.37 (59.97; −0.60) | SYN |
| C. kefyr | V2108462 | 0.004 | 16 | 0.001/16 | 0.5 | SYN | 91.47 (97.01; −5.54) | SYN |
FICI, fractional inhibitory concentration index; INTPN, interpretation; SYN, synergy; IND, no interaction; ISA, isavuconazole; COL, colistin; ATCC, American Type Culture Collection; DSM, Deutsche Sammlung von Mikroorganismen und Zellkulturen; MIC, minimum inhibitory concentration.