Azole resistance and cyp51A mutation screening in Aspergillus fumigatus in Mexico.
J Antimicrob Chemother. 2019 Apr 08;:
Authors: Gonzalez-Lara MF, Roman-Montes CM, Diaz-Lomeli P, Rangel-Cordero A, Valenzuela MO, Ponce-de-Leon A, Sifuentes-Osornio J, Ostrosky-Zeichner L, Martinez-Gamboa A
BACKGROUND: Fungicide exposure in the environment has driven the emergence of azole-resistant Aspergillus fumigatus worldwide. A screening test allows identification of resistant isolates.
OBJECTIVES: We screened clinical samples for azole-resistant Aspergillus through azole-containing agar plates and identified mutations in the cyp51A gene of A. fumigatus.
METHODS: Aspergillus isolates from clinical samples collected in a tertiary care centre from 2014 to 2017 were screened for azole resistance. Samples were subcultured in azole-containing agar plates. Isolates with a positive screening test were subject to DNA extraction, DNA amplification and sequencing of the cyp51A gene (coding and promoter regions). Clinical data were obtained from medical records.
RESULTS: We screened 43 Aspergillus isolates from 39 patients for azole resistance. Three isolates from three patients grew on azole-containing agar plates: two A. fumigatus and one Aspergillus flavus. PCR analysis and cyp51A sequencing identified the TR34/L98H mutation in both A. fumigatus isolates. The prevalence of cyp51A mutations among A. fumigatus was 8.3% (2/24). Both patients with TR34/L98H mutants were azole naive and presented with invasive aspergillosis; one had multiple myeloma and the other was a liver retransplant recipient. They suffered progressive disease and failed voriconazole therapy.
CONCLUSIONS: To the best of our knowledge, this is the first report of azole-resistant A. fumigatus with the TR34/L98H mutation in two azole-naive patients with refractory invasive aspergillosis in Mexico.
PMID: 31220262 [PubMed – as supplied by publisher]