Indoor Air Contamination by Yeasts in Healthcare Facilities: Risks of Invasive Fungal Infection

Abstract

Introduction-Aims: Fungi are ubiquitous microorganisms that are easily dispersed through the air. In healthcare environments, indoor air can favor the spread of healthcare-associated fungal infections, compromising mainly immunocompromised hospitalized individuals. Therefore, this study aimed to evaluate indoor air contamination in healthcare environments, investigating mainly the presence of potentially pathogenic yeasts. Method: Indoor air samples were collected from 12 healthcare environments (hospital and medical clinics). After the growth, isolation, and purification of the yeast colonies, the isolates were identified by polymerase chain reaction using species-specific primers for yeasts of the genus Candida and sequencing of D1/D2 domains of the large ribosomal subunit (LSU rRNA). Results and interpretation: Fourteen yeast species were identified, including emerging pathogens. Species of clinical importance such as Candida parapsilosis, Candida glabrata, and Rhodotorula mucilaginosa were present. C. parapsilosis was the most prevalent species, followed by Rhodotorula mucilaginosa. In addition, we report the first occurrence of Candida orthopsilosis, Trichosporon mucoides, Fereydounia khargensis, and Hortaea werneckii in indoor air samples collected in healthcare environments. The present study shows that potentially fungal pathogens were present in air samples from healthcare environments, proving the role of indoor air in spreading infections. Therefore, monitoring air quality in healthcare environments is a fundamental approach to developing infection control measures, especially those related to invasive fungal infections.