In Vitro Activities of Echinocandins againstCandida kruseiDetermined by Three Methods: MIC and Minimal Fungicidal Concentration Measurements and Time-Kill Studies

We evaluated the in vitro activities of anidulafungin, micafungin, and caspofungin against Candida krusei by determining MIC and minimum fungicidal concentration (MFC) measurements and by the time-kill method. The geometric mean (GM)-MIC/GM-MFC values were 0.1/0.34, 0.25/0.44, and 1/2.29, respectively. The mean times to reach 99.9% growth reduction were 19.1 +/- 18.2 h (mean +/- standard deviation) for 2 mg/liter anidulafungin, 37.4 +/- 8.8 h for 2 mg/liter caspofungin, and 30.7 +/- 12.2 h for 1 mg/liter micafungin. Anidulafungin exhibited the highest time-kill rate, followed by micafungin. The three echinocandins showed fungicidal activity at concentrations reached in serum.