Detection of TR34/L98H CYP51A Mutation through Passive Surveillance for Azole-Resistant Aspergillus fumigatus in the United States from 2015 to 2017.

The emergence of azole-resistant Aspergillus fumigatus has become a clinical problem in many parts of the world. Several amino acid mutations in the azole target protein Cyp51Ap contribute to this resistance, with the most concerning being the environmentally derived TR34/L98H and TR46/Y121F/T289A mutations. Here, we performed passive surveillance to assess a sample of the A. fumigatus population in the United States for the presence of these mutations. We found 1.4% of those isolates to exhibit elevated MIC via broth microdilution, and five of those isolates harbored the TR34/L98H mutation.