Azole Antifungal Susceptibility Testing of Candida Species Using E test

Kim, Yeon Jin; Suh, Moo Kyu; Ha, Gyoung Yim

Abstract

BACKGROUND: Because of recently increasing reports of azole-resistant Candida species, it is necessary to perform antifungal susceptibility test. E test(AB Biodisk, Sweden) is a rapid, easy-to- perform in-vitro antifungal susceptibility test.
OBJECTIVE
The purpose of the study was to investigate the minimal inhibitory concentration(MIC) of azole antifungal agents against Candida sp. isolated from skin lesion using E test.
METHODS
Twenty-seven clinical isolates of Candida sp.(including 24 C. albicans, 2 C. parapsilosis, and 1 C. guilliermondii) were tested. MIC endpoints of E test for itraconazole(ICZ) and fluconazole (FCZ) susceptibility were read after 24 hours for each isolates on Casitone agar.
RESULTS
MIC of azole antifungal agents against Candida sp. : MIC of ICZ was 0.008-1.0microgram/mL on C. albicans, 0.023-0.125microgram/mL on C. parapsilosis, and 0.064microgram/mL on C. guilliermondii. MIC of FCZ was 0.5-4.0microgram/mL on C. albicans, 1.5-2.0microgram/mL on C. parapsilosis, and 0.5microgram/mL on C. guilliermondii. According to NCCLS(National Committee for Clinical Laboratory Standards) guidelines, two strains of C. albicans isolated from patients with Candidal intertrigo showed ICZ-resistant.
CONCLUSION
We found that E test represented a simple and valuable method for susceptibility test for Candida sp.