Comparison of interpretation of in vitro susceptibilities of trailing isolates of C. albicans and C. tropicalis to fluconazole and itraconazole as determined by broth microdilution testing with six different methods of end point determination and by sterol quantitation

Method of end point determinationNo. of isolates in susceptibility category
C. albicansC. tropicalis
Fluconazole (n = 78)Itraconazole (n = 70)Fluconazole (n = 70)Itraconazole (n = 35)
Visual, 24-h incubation7800700070003500
Visual, 48-h incubation0078007000700035
Spectrophotometric, 24-h incubation, 50% growth inhibition7800700070003500
Spectrophotometric, 48-h incubation, 50% growth inhibition7413664066223311
Spectrophotometric, 24-h incubation, 80% growth inhibition7404661370003500
Spectrophotometric, 48-h incubation, 80% growth inhibition1815914749171524427
Sterol quantitation7800700068203500