Comparative evaluation of Fungitest-, Neo-Sensitabs- and M27T-NCCLS broth microdilution methods for antifungal drug susceptibility testing of Candida species and Cryptococcus neoformans.
Two commercial antifungal susceptibility testing systems (Fungitest and Neo-Sensitabs) were compared with the M27T-NCCLS reference broth microdilution method using one hundred isolates of Candida sp. and Crptococcus neoformans. Six different antifungal drugs were tested: amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, ketoconazole and miconazole. The overall agreement between the Fungitest and the reference methods was much better than between the Neo-Sensitabs and the reference methods: the agreement for the Fungitest ranged from 100% for amphotericin B to 76.7% for itraconazole whereas for the Neo-Sensitabs, it ranged from 90.4% for amphotericin B to 36% for ketoconazole. For the total number of tests performed with Neo-Sensitabs, there were 37.8% of discrepancies with the reference method whereas for the tests performed with Fungitest, there was only 16.5% of discrepancies. Major discrepancies, defined as results that classified an isolate as susceptible by one method and resistant by another, occurred in 21 cases for the Neo-Sensitabs test and only in four cases with the Fungitest, namely 0.6% of the cases. We conclude that the Fungitest method constitutes a simple and reliable procedure for antifungal drug susceptibility testing.
Swinne
D
D
Institute of Tropical Medicine Prince Leopold, Antwerp, Belgium. dswinne@itg.be
Raes-Wuytack
C
C
Van Looveren
K
K
Desmet
P
P
D000666:Amphotericin B / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D003455:Cryptococcus neoformans / Q000187:drug effects*; D015725:Fluconazole / Q000494:pharmacology; D005437:Flucytosine / Q000494:pharmacology; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology; D007654:Ketoconazole / Q000494:pharmacology; D008825:Miconazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D011933:Reagent Kits, Diagnostic / Q000382:microbiology*
D000935:Antifungal Agents; D011933:Reagent Kits, Diagnostic; D017964:Itraconazole; D008825:Miconazole; D000666:Amphotericin B; D015725:Fluconazole; D005437:Flucytosine; D007654:Ketoconazole