TABLE 2.
Interactions of isavuconazole with caspofungin, micafungin, and anidulafungin against Aspergillus spp., determined with the checkerboard broth microdilution technique using two inhibition endpointsa
| Inhibition endpoint and species | No. of isolates |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Isavuconazole with caspofungin |
Isavuconazole with micafungin |
Isavuconazole with anidulafungin |
|||||||
| S | I | A | S | I | A | S | I | A | |
| Complete inhibition endpoint | |||||||||
| Azole-resistant A. fumigatus (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| Azole-susceptible A. fumigatus (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| A. niger (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| A. terreus (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| A. flavus (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| A. nidulans (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| Total (30 isolates) | 0 | 30 | 0 | 0 | 30 | 0 | 0 | 30 | 0 |
| Partial inhibition endpoint | |||||||||
| Azole-resistant A. fumigatus (5 isolates) | 1 | 4 | 0 | 1 | 4 | 0 | 0 | 5 | 0 |
| Azole-susceptible A. fumigatus (5 isolates) | 2 | 3 | 0 | 4 | 1 | 0 | 1 | 4 | 0 |
| A. niger (5 isolates) | 3 | 2 | 0 | 4 | 1 | 0 | 3 | 2 | 0 |
| A. terreus (5 isolates) | 1 | 4 | 0 | 1 | 4 | 0 | 1 | 4 | 0 |
| A. flavus (5 isolates) | 0 | 5 | 0 | 1 | 4 | 0 | 0 | 5 | 0 |
| A. nidulans (5 isolates) | 0 | 5 | 0 | 0 | 5 | 0 | 0 | 5 | 0 |
| Total (30 isolates) | 7 | 23 | 0 | 11 | 19 | 0 | 5 | 25 | 0 |
a
For isavuconazole, MICs were defined as the lowest concentrations of the antifungal agents that completely inhibited fungal growth. For the echinocandins, two different visual determinations of the endpoint were performed, i.e., complete inhibition of growth (MIC) and partial inhibition of growth defined as the lowest drug concentration resulting in aberrant hyphal growth (MEC), by examination with an inverted microscope. S, synergism; I, indifference; A, antagonism.