Figure 7. Calcineurin inhibitor exhibits synergistic antifungal activity with caspofungin against C. lusitaniae wild-type and echinocandin-resistant strains.

Disk diffusion assays were used to determine synergistic antifungal activity with caspofungin against clinical echinocandin-resistant C. lusitaniae strains. Cells were grown overnight at 30°C, and 0.1 OD₆₀₀ (in 100 µl) was spread on the surface of RPMI media lacking or containing FK506 (1 µg/ml). A disk was placed on the surface of the medium and 12.5 µg caspofungin (5 µl of 2.5 mg/ml) was added to each disk. The plates were incubated at 30°C for 48 h and photographed. S = caspofungin-sensitive; R = caspofungin-resistant (less susceptible). Scale bar = 6 mm.