Clinical Evaluation of the Sensititre^R YeastOne^R Colorimetric Antifungal Panel for Antifungal Susceptibility Testing of the Echinocandins Anidulafungin, Caspofungin, and Micafungin

University of Iowa College of Medicine, Iowa City, Iowa; New York State Department of Health, Albany, NY; Case Western Reserve University, Cleveland, OH; TREK Diagnostic Systems, Cleveland, OH

^* To whom correspondence should be addressed. Email: michael-pfaller{at}uiowa.edu.

	Abstract

A commercially-prepared, dried colorimetric microdilution panel (Sensititre^R YeastOne^R; TREK Diagnostic Systems, Cleveland, OH) was compared in three different laboratories with the Clinical and Laboratory Standards Institute (CLSI) reference microdilution method by testing two quality control strains, 25 reproducibility strains and 404 isolates of Candida spp. against anidulafungin, caspofungin, and micafungin. Reference MIC endpoints and YeastOne colorimetric endpoints were read after 24 h of incubation. YeastOne endpoints were determined to be the lowest concentration at which the color in the well changed from red (positive, indicating growth) to blue (negative, indicating no growth). Excellent essential agreement (within two dilutions) between the reference and colorimetric MICs was observed. Overall agreement was 100% for all three agents. Categorical agreement ranged from 99.3% (anidulafungin) to 100% (caspofungin, micafungin) and interlaboratory reproducibility was 99%. The YeastOne colorimetric method appears to be comparable to the CLSI reference method for testing the susceptibility of Candida spp. to the echinocandins anidulafungin, caspofungin, and micafungin.