Dannaoui E, et al. – This study aims at validating the new MycoGENIE A. fumigatus real–time PCR kit and evaluating its performance in clinical samples for the detection of A. fumigatus and its azole resistance. As per results, this new real–time PCR kit enables sensitive and rapid detection of A. fumigatus DNA and azole resistance due to TR34/L98H mutations in clinical samples.

Methods

• By targeting the 28S–rRNA multicopy gene and specific TR34 and L98H mutations in the cyp51Asingle copy gene of A. fumigatus, this multiplex assay seemed detecting DNA from the A. fumigatus species complex.
• Assessment of the specificity of cyp51A mutation detection was performed by testing DNA samples from 25 wild–type or mutated clinical A. fumigatus isolates.

Results

• Researchers performed clinical validation on 88 respiratory samples obtained from 62 patients, and on 69 serum samples obtained from 16 patients with proven or probable aspergillosis and from 13 patients without aspergillosis.
• Observations revealed that the limit of detection was below one copy for the Aspergillus 28S–rRNA gene and six copies for the cyp51A gene harboring the TR34/L98H alterations.
• There appeared no cross–reactivity with various fungi and bacteria.
• qPCR analysis accurately detected all isolates harboring the TR34/L98H mutations.
• In respiratory samples, qPCR results indicated a sensitivity and specificity of 92.9% and 90.1%, respectively, while in serum samples, the sensitivity and specificity of 100% and 84.6% were evident, respectively.