Standardized susceptibility testing of fluconazole: an international collaborative study.
An international collaborative study of broth dilution (MIC) and disk diffusion susceptibility testing of fluconazole was conducted by using a chemically defined medium (High-Resolution Antifungal Assay Medium; Oxoid Ltd., Basingstoke, United Kingdom) and standard test methods performed in eight reference laboratories. Ten yeast isolates were tested by each test method in duplicate on each of 3 separate days. The intralaboratory reproducibility of the MIC test was excellent; 95.7% of the replicate tests (n = 220) were within 2 doubling dilutions of the other values in the set for the eight laboratories. The intralaboratory reproducibility of the disk test was also good, with 91% of the replicate tests (n = 234) agreeing with each other within an arbitrarily chosen value of 4 mm. Interlaboratory agreement of MIC test results was acceptable, with 84% of the MICs agreeing within 2 doubling dilutions. In contrast, the interlaboratory agreement of the disk test was not good, with only 59% of test results agreeing within 4 mm. Comparison of the rank order of MICs obtained in each laboratory with the reference rank order gave an agreement of 70 to 80% (median, 80%) with the MIC test and 70 to 90% (median, 80%) with the disk test. These preliminary results are encouraging for the development of standardized testing methods for testing fluconazole.
Pfaller
M A
MA
Department of Pathology, Oregon Health Sciences University, Portland 97201.
Dupont
B
B
Kobayashi
G S
GS
Müller
J
J
Rinaldi
M G
MG
Espinel-Ingroff
A
A
Shadomy
S
S
Troke
P F
PF
Walsh
T J
TJ
Warnock
D W
DW
D003470:Culture Media; D015725:Fluconazole / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*; D007391:International Cooperation; D008826:Microbial Sensitivity Tests
D003470:Culture Media; D015725:Fluconazole