An Evaluation of the Performance of a New Investigational Antifungal Agent, Caspofungin, on the Sensititre® YeastOne® Colorimetric Antifungal Susceptibility Plate.


Author address: 

1 Trek Diagnostic Systems, Westlake, OH, 2 Medical College of Virginia, Richmond, VA, 3 University of Iowa, College of Medicine, Iowa City, IA


A multisite study was undertaken to evaluate the performance of Caspofungin, a new investigational antifungal agent (Merck & Co. Inc., WestPoint, PA) on Sensititre's YeastOne Plate. MIC results of Caspofungin were determined with the YeastOne plate using a 2-fold serial dilution range of 16 - 0.008µg/ml with alamarBlue® as a colorimetric indicator. A challenge set of 100 Candida isolates were selected and distributed to each of three test sites to evaluate the performance and reproducibility of the antifungal assay. The YeastOne plate was tested at each site along with the NCCLS M27 reference Broth Microdilution method (RPMI 1640) for comparison. MIC's were read manually after being incubated at 35°C for 24 and 48 hours. Essential agreements with-in ±2 serial dilutions were calculated for each of the sites, and for all sites combined. Essential agreements for each of the individual sites were 99%, 99%, and 96% at 24 hours, and 97%, 98%, and 96% at 48 hours. Combined site agreement for Caspofungin was 98% at 24 hours and 97% at 48 hours. The combined site essential agreements at 24 hours for each species were C. albicans 100%, C. glabrata 99%, C. parapsilosis 100%, C. krusei 95%, C. lusitania 93%, and C. tropicalis 96%. Overall the Sensititre YeastOne Antifungal Susceptibility Plate, for testing Caspofungin, shows excellent agreement with the NCCLS M27 reference method.

abstract No: 


Full conference title: 

    • ICAAC 42nd