Aspergillus fumigatus strains with mutations in the cyp51A gene do not always show phenotypic resistance to itraconazole, voriconazole, or posaconazole.

We performed molecular identification of 98 Aspergillus fumigatus complex isolates with MICs of 1 to 4 μg/ml for itraconazole and searched for the presence of mutations in cyp51A. Most of the isolates (91%) belonged to A. fumigatus sensu stricto. We found 14 different mutations in nine isolates at codons different from G54, M220, G138, G448, and L98. We report new mutations at positions 165, 262, 479, and 497 (silent). The role of these mutations should be analyzed.