Prevalence and mechanisms of azole resistance in clinical isolates of Aspergillus section Fumigati species in a Canadian tertiary care centre, 2000 to 2013.

OBJECTIVES: Azole resistance among Aspergillus fumigatus isolates is a growing concern worldwide. Induction of mutations during azole therapy, environment-acquired mutations caused by azole fungicides and intrinsic resistance of cryptic Fumigati species all contribute to the burden of resistance. However, there is a lack of data in Canada on this emerging threat. METHODS: To gain insights into the magnitude and mechanisms of resistance, a 14 year collection of Aspergillus section Fumigati comprising 999 isolates from 807 patients at a Montreal hospital was screened for azole resistance, and resistance mechanisms were investigated with the combined use of genome sequencing, 3D modelling and phenotypic efflux pump assays. RESULTS: Overall azole resistance was low (4/807 patients; 0.5%). A single azole-resistant A. fumigatus sensu stricto strain, isolated from a patient with pulmonary aspergillosis, displayed efflux-pump-mediated resistance. Three patients were colonized or infected with azole-resistant cryptic Fumigati species (one Aspergillus thermomutatus, one Aspergillus lentulus and one Aspergillus turcosus). Evidence is presented that azole resistance is efflux-pump-mediated in the A. turcosus isolate, but not in the A. lentulus and A. thermomutatus isolates. CONCLUSIONS: Azole resistance is rare in our geographic area and currently driven by cryptic Fumigati species. Continued surveillance of emergence of resistance is warranted.

Draft Genome Sequence of Azole-Resistant Aspergillus thermomutatus (Neosartorya pseudofischeri) Strain HMR-AF-39, Isolated from a Human Nasal Septum Abscess Aspirate.

Here, we present the draft genome sequence of Aspergillus thermomutatus (formerly known as Neosartorya pseudofischeri; strain HMR-AF-39/LSPQ-01276), a cryptic species of Aspergillus section Fumigati. This species is intrinsically resistant to antifungal azoles and is recognized as an agent of invasive aspergillosis among immunocompromised hosts.

Draft Genome Sequences of Azole-Resistant and Azole-Susceptible Aspergillus turcosus Clinical Isolates Recovered from Bronchoalveolar Lavage Fluid Samples.

We present the draft genome sequences of two clinical strains of Aspergillus turcosus, one azole-susceptible (strain HMR-AF-23/LSPQ-01275) and the other azole-resistant (strain HMR-AF-1038/LSPQ-01280), isolated from bronchoalveolar lavage fluid of two adult patients. These two strains are the first reported clinical isolates of A. turcosus.