Antifungal-resistant Mucorales in different indoor environments

• Published in: Mycology Vol. 10; no. 2; pp. 75 - 83
• Main Authors: Caetano, Liliana Aranha, Faria, Tiago, Springer, Jan, Loeffler, Juergen, Viegas, Carla
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis 01.06.2019; Taylor & Francis Ltd; Taylor & Francis Group
• Subjects: Agricultural wastes; Air conditioners; Air conditioning; antifungal drug-resistance; Bakery products; Culture; Culture media; Drug resistance; Dust collectors; Dust filters; Dwellings; Farms; Filters; Fungicides; Identification methods; Indoor environments; Itraconazole; Livestock; Mucor; Mucorales; Raw materials; Rhizopus; Selective media; Swine; Taxis; Voriconazole; Waste sorting; Workplaces; Mucorales; antifungal drug-resistance; indoor environments
• ISSN: 2150-1203; 2150-1211
• DOI: 10.1080/21501203.2018.1551251

This paper sought to address the prevalence of Mucorales in different indoor environments in Portugal. Environmental samples (183 in total) were collected at dwellings (n = 79) and workplaces (bakeries, swine farms, taxis, waste-sorting plants) (n = 93) by passive sampling using electrostatic dust collector (EDC), air-conditioning filters, litter, and/or raw materials. Samples were inoculated onto non-selective MEA and DG18 media and were screened for antifungal drug-resistance in azole-supplemented agar Sabouraud media. A probe-based Mucorales-specific real-time PCR assay (Muc18S) was used to detect Mucorales in complement to conventional culture-based methods. Mucorales order was found as more prevalent in air-conditioning filters from waste-sorting fork lifters (35.7%). Amongst Mucorales isolates able to grow in azole-supplemented media, 16 isolates of Mucor sp., Rhizopus sp. or Rhizomucor sp. were not susceptible to 1 mg/L voriconazole, and four isolates of Mucor sp. or Rhizopus sp. were not susceptible to 4 mg/L itraconazole. In conclusion, combination of the culture-based and molecular methods proved to be reliable for Mucorales order identification in complex environmental samples.