Colorimetric method for susceptibility testing of voriconazole and other triazoles against Candida species.
A microdilution assay using Alamar Blue, a colorimetric indicator, was compared with the NCCLS macrodilution broth assay for voriconazole, fluconazole, and itraconazole against Candida albicans, Candida glabrata, and Candida krusei. Concordance (+/- 2 dilutions) between the two methods was highest for voriconazole (98.3%), and for fluconazole and itraconazole it was 94.3 and 95.4%, respectively. Twenty-six of 32 (81.2%) discordant readings (> or = 3 dilutions different) were noted in C. glabrata isolates, and all but two isolates showing discordance had higher minimum inhibitory concentration readings with the colorimetric method.
Kauffman
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Department of Internal Medicine, Ann Arbor Veterans Affairs Health System, University of Michigan Medical 48105, USA. ckauff@umich.edu
Zarins
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D000935:Antifungal Agents / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects*; D003124:Colorimetry / Q000379:methods; D004396:Coloring Agents; D015725:Fluconazole / Q000494:pharmacology; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000379:methods*; D010078:Oxazines; D011743:Pyrimidines / Q000494:pharmacology*; D014230:Triazoles / Q000494:pharmacology*; D065819:Voriconazole; D014966:Xanthenes
D000935:Antifungal Agents; D004396:Coloring Agents; D010078:Oxazines; D011743:Pyrimidines; D014230:Triazoles; D014966:Xanthenes; C005843:resazurin; D017964:Itraconazole; D015725:Fluconazole; D065819:Voriconazole