of fluconazole, itraconazole, voriconazole, and posaconazole were compared ... and reference values was good with fluconazole and voriconazole (93 to 97%).
JOURNAL OF CLINICAL MICROBIOLOGY, Sept. 2005, p. 4535–4540 0095-1137/05/$08.00⫹0 doi:10.1128/JCM.43.9.4535–4540.2005 Copyright © 2005, American Society for Microbiology. All Rights Reserved.
Vol. 43, No. 9
Comparison of Visual 24-Hour and Spectrophotometric 48-Hour MICs to CLSI Reference Microdilution MICs of Fluconazole, Itraconazole, Posaconazole, and Voriconazole for Candida spp.: a Collaborative Study A. Espinel-Ingroff,1* F. Barchiesi,2 M. Cuenca-Estrella,3 A. Fothergill,4 M. A. Pfaller,5 M. Rinaldi,4 J. L. Rodriguez-Tudela,3 and P. E. Verweij6 VCU Medical Center, Richmond, Virginia1; Public Health, Ancona, Italy2; Instituto Salud Carlos III, Majadahonda, Spain3; University of Texas Health Science Center, San Antonio, Texas4; University of Iowa College of Medicine, Iowa City, Iowa5; and Medical Center Nijmegen, Nijmegen, The Netherlands6 Received 27 March 2005/Returned for modification 31 May 2005/Accepted 13 June 2005
A multicenter (six-center) study evaluated the performance (interlaboratory reproducibility, compatibility with reference methods, and categorical agreement) of 24-h visual and 48-h spectrophotometric MICs. MICs of fluconazole, itraconazole, voriconazole, and posaconazole were compared to reference 48-h microdilution broth visual MICs (CLSI [formerly NCCLS] M27-A2 document) for 71 isolates of Candida spp. that included 10 fluconazole-resistant strains. Twenty readings (5%) were reported as showing no growth at 24 h, mostly for Candida dubliniensis and from a single center. The overall interlaboratory agreement of 24-h visual readings and 48-h spectrophotometric MICs, as well their compatibility with reference values, were excellent with the four triazoles for most of the species (93 to 99%, within 3 dilutions). The categorical agreement between the investigational reading conditions and reference values was good with fluconazole and voriconazole (93 to 97%) but lower with itraconazole (86 to 88%), due primarily to minor errors. There were only 0 to 3% very major errors with these three triazoles; the number of substantial errors (more than three dilutions) was also low (
