Incidence of Cyp51 A key mutations in Aspergillus fumigatus-a study on primary clinical samples of immunocompromised patients in the period of 1995-2013.

As the incidence of azole resistance in Aspergillus fumigatus is rising and the diagnosis of invasive aspergillosis (IA) in immunocompromised patients is rarely based on positive culture yield, we screened our Aspergillus DNA sample collection for the occurrence of azole resistance mediating cyp51 A key mutations. Using two established, a modified and a novel polymerase chain reaction (PCR) assays followed by DNA sequence analysis to detect the most frequent mutations in the A. fumigatus cyp51 A gene conferring azole resistance (TR34 (tandem repeat), L98H and M220 alterations).

Development of novel PCR assays to detect azole resistance-mediating mutations of the Aspergillus fumigatus cyp51A gene in primary clinical samples from neutropenic patients.

The increasing incidence of azole resistance in Aspergillus fumigatus causing invasive aspergillosis (IA) in immunocompromised/hematological patients emphasizes the need to improve the detection of resistance-mediating cyp51A gene mutations from primary clinical samples, particularly as the diagnosis of invasive aspergillosis is rarely based on a positive culture yield in this group of patients. We generated primers from the unique sequence of the Aspergillus fumigatus cyp51A gene to establish PCR assays with consecutive DNA sequence analysis to detect and identify the A. fumigatus cyp51A tandem repeat (TR) mutation in the promoter region and the L98H and M220 alterations directly in clinical samples.