Comparison of the Sensititre YeastOne Colorimetric antifungal Panel and Etest Method with the NCCLS M27-A Reference Method for In Vitro Testing of Posaconazole (POS) and Other Azoles against Candida spp.


Author address: 

Schering-Plough Research Institute, Kenilworth, NJ.


Background: The determination of yeast susceptibility to antifungal agents is becoming increasingly important with the advent of new antifungal agents and the emergence of resistance to existing drugs. The objective of this study was to compare the Sensititre YeastOne (Trek Diagnostics) and Etest (AB Biodisk) methods to the standard NCCLS M27-A methodology against Candida spp. using POS, Itraconazole (ITZ), Fluconazole (FLU), and Amphotericin B (AmB). Methods: 39 recent clinical isolates of various species of Candida [(C. albicans (n=29), C. dubliniensis (n=4), C. glabrata (n=4), C. krusei (n=1) and C. parapsilosis (n=1)] were tested for antifungal susceptibility by the three methods. Etest and Sensititre YeastOne were performed following the manufacturer's recommendations. Microbroth dilution was performed following the NCCLS M27-A document. Results: Agreement for all isolates, ± two dilutions, for POS was 93% for the Sensititre method and 83% for the Etest method compared to NCCLS. Agreement for C. albicans between Sensititre and Etest were: POS 92%, 76%; FLU 95%, 92%; ITZ 85%, 69% and AmB 95%, 86%, respectively. Conclusions: The Sensititre method showed better overall agreement with the NCCLS reference method than did the Etest. Interpretation of the Etest endpoint for azoles was more difficult to determine because of trailing endpoints.

abstract No: 


Full conference title: 

43rd Interscience Conference on Antimicrobial Agents
    • ICAAC 43rd