Mycobiome of air purifier filters in allergic bronchopulmonary mycosis patients' homes

In recent years, the number of patients diagnosed with allergic bronchopulmonary mycosis (ABPM), a chronic disease caused by fungal colonization in the bronchi, has increased. ABPM has been associated not only with Ascomycetes such as Aspergillus fumigatus and A. niger from the Aspergillus genus, but also with Basidiomycetes, including Schizophyllum commune. However, long-term investigations of indoor mycobiome in the homes of ABPM patients remain limited. Therefore, the objective of this study was to ascertain the extent of microbial contamination in the homes of ABPM patients. In this study, air purifiers were installed in the living rooms and bedrooms of 10 ABPM patients for a two-month period. Fungi adhering to the collected filters were analyzed by next-generation sequencing (NGS) targeting the ITS1 region, and the fungal communities were analyzed in a total of 16 samples. The results demonstrated that Basidiomycetes accounted for at least 60% of all samples, with an average of over 82%. Conversely, Ascomycota accounted for an average of 2.9% or less, indicating a substantial imbalance between both groups. Analysis of the genera Schizophyllum revealed species identified as potential causative agents of ABPM. Furthermore, ß diversity analysis revealed that the fungal communities inhabiting the living rooms and bedrooms within each residence were similar. This finding suggests shared characteristics among fungal communities within a single residence, despite functional differences among rooms.