Azole resistance in Aspergillus species in Southern Taiwan: an epidemiological surveillance study.
Mycoses. 2019 Sep 23;:
Authors: Chen YC, Kuo SF, Wang HC, Wu CJ, Lin YS, Li WS, Lee CH
BACKGROUND AND OBJECTIVES: Poor clinical outcomes for invasive aspergillosis are associated with antifungal resistance. Performing antifungal susceptibility tests on clinically relevant Aspergillus isolates from patients and environmental regions with known azole resistance is recommended. The aim of the study was to assess the presence of azole-resistance in clinical Aspergillus spp. isolates and those from hospital environments and farmlands within a 40 km radius of the hospital.
METHODS: Clinical Aspergillus spp. isolates were cultured, as well as environmental Aspergillus spp. isolates obtained from air samples. Samples were subcultured in azole-containing agar plates. Isolates with a positive screening test were subjected to YeastOne methods to determine their minimum inhibitory concentrations of antifungals. Resistance mechanisms were investigated in the azole-resistant Aspergillus spp. isolates.
RESULTS: No azole-resistant clinical or environmental A. flavus, A. oryaze, A. niger or A. terreus isolates were found in the present study. All A. fumigatus clinical isolates were azole-susceptible. Seven A. fumigatus environmental isolates were associated with cyp51A mutations, including 2 that harbored TR34 /L98H mutations with S297T/F495I substitutions, 2 with TR34 /L98H mutations and 3 with TR46 /Y121F/T289A mutations. One of these isolates was collected from farmland, 1 was from A ward and 5 were from B ward. The proportion of azole-resistant A. fumigatus was 10.2% (6/59) and 3.2% (1/31) in the hospital environments and the farmlands near the hospital, respectively.
CONCLUSIONS: It was observed that azole-resistant A. fumigatus existed within hospital environments. This emphasizes the importance of periodic surveillance in hospital environments, and monitoring for the emergence of azole-resistant A. fumigatus clinical isolates.
PMID: 31549427 [PubMed – as supplied by publisher]