Time of incubation for antifungal susceptibility testing of Aspergillus fumigatus: can MIC values be obtained at 24 hours?

A collection of Aspergillus fumigatus isolates was used to check if MICs can be read at 24 h. At 24 h, the geometric mean MIC of itraconazole for resistant isolates was determined to be 5.11 mg/liter, but the MIC was read as 16 mg/liter at 48 h. At 24 h, MICs for 51.5% of resistant strains were determined to be <or =2 mg/liter. MICs must be obtained at 48 h.