TABLE 4.

Inhibition of ergosterol biosynthesis in A. fumigatus itraconazole-resistant mutants

Strain	% Inhibitiona
CEA17 (wild type)b	100
G10-1-50A	0
G10-2-50A	62
G10-3-50A	0
G10-1-50Bc	91
H05-3-10	42
H10-1-50A	76
H10-2-50A	35
H10-3-50Ad	0
H10-1-50Be	37

^aPercent inhibition of ergosterol biosynthesis at 64 μg/ml relative to that for the drug-free growth control. Based on the studies with C. albicans, the MIC by SQM was defined as the drug concentration which inhibited ergosterol biosynthesis by ≥80% relative to that for the drug-free control. However, studies have not been done with A. fumigatus to determine what MIC end point is most appropriate. However, by use of the guidelines for C. albicans, the MICs for all mutants except strain G10-1-50B would be >16 μg/ml; that for strain G10-1-50B would be 1 μg/ml.

^bNo growth was detected at any drug concentration, even after 48 h of growth.

^cDramatically reduced growth was detected at all drug concentrations after 24 h of incubation. Adequate growth was detected at 48 h, and 61% inhibition of ergosterol biosynthesis was detected at 16 μg/ml.

^dDramatically reduced growth was detected at all drug concentrations after 24 h of incubation. Adequate growth was detected at 48 h.

^eDramatically reduced growth was detected at 16 and 64 μg/ml after 24 h of incubation. Adequate growth was detected at 48 h.