Evaluation of the NCCLS M44-P disk diffusion method for determining susceptibilities of 276 clinical isolates of Cryptococcus neoformans to fluconazole.
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.
Pfaller
M A
MA
Department of Pathology, Roy J and Lucille A Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA. michael-pfaller@uiowa.edu
Messer
S A
SA
Boyken
L
L
Rice
C
C
Tendolkar
S
S
Hollis
R J
RJ
Diekema
D J
DJ
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
D000935:Antifungal Agents; D015725:Fluconazole