title: Evaluation of the NCCLS M44-P disk diffusion method for determining susceptibilities of 276 clinical isolates of Cryptococcus neoformans to fluconazole.
abstract: We evaluated the NCCLS M44-P fluconazole disk diffusion method in comparison with the NCCLS M27-A2 broth microdilution method for determining the susceptibility of 276 isolates of Cryptococcus neoformans. Disk diffusion testing was performed using Mueller-Hinton agar supplemented with 2% glucose and 0.5 microg of methylene blue/ml. Among the 276 isolates, 259 (93.8%) were susceptible, 16 (5.8%) were susceptible--dose dependent, and 1 (0.4%) was resistant to fluconazole as determined by the NCCLS broth microdilution method. The overall categorical agreement between the two methods was 86%, with 0% very major errors, 2% major errors, and 12% minor errors. The disk diffusion method using Mueller-Hinton agar supplemented with glucose and methylene blue appears to be a useful approach for determining the fluconazole susceptibility of C. neoformans.
authors.affiliation: Department of Pathology, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA. michael-pfaller@uiowa.edu
authors.forename: M A
authors.initials: MA
authors.lastname: Pfaller
authors.forename: S A
authors.initials: SA
authors.lastname: Messer
authors.forename: L
authors.initials: L
authors.lastname: Boyken
authors.forename: C
authors.initials: C
authors.lastname: Rice
authors.forename: S
authors.initials: S
authors.lastname: Tendolkar
authors.forename: R J
authors.initials: RJ
authors.lastname: Hollis
authors.forename: D J
authors.initials: DJ
authors.lastname: Diekema
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D003455:Cryptococcus neoformans / Q000187:drug effects*; D004058:Diffusion; D015725:Fluconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods* / Q000592:standards; D011786:Quality Control
chemical_list: D000935:Antifungal Agents; D015725:Fluconazole