title: Standardized susceptibility testing of fluconazole: an international collaborative study.
abstract: 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.
authors.affiliation: Department of Pathology, Oregon Health Sciences University, Portland 97201.
authors.forename: M A
authors.initials: MA
authors.lastname: Pfaller
authors.forename: B
authors.initials: B
authors.lastname: Dupont
authors.forename: G S
authors.initials: GS
authors.lastname: Kobayashi
authors.forename: J
authors.initials: J
authors.lastname: Müller
authors.forename: M G
authors.initials: MG
authors.lastname: Rinaldi
authors.forename: A
authors.initials: A
authors.lastname: Espinel-Ingroff
authors.forename: S
authors.initials: S
authors.lastname: Shadomy
authors.forename: P F
authors.initials: PF
authors.lastname: Troke
authors.forename: T J
authors.initials: TJ
authors.lastname: Walsh
authors.forename: D W
authors.initials: DW
authors.lastname: Warnock
mesh_terms: D003470:Culture Media; D015725:Fluconazole / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects*; D007391:International Cooperation; D008826:Microbial Sensitivity Tests
chemical_list: D003470:Culture Media; D015725:Fluconazole