Analysis of fungal bioaerosols in Athens: a pilot study.

This pilot study is the first attempt to describe the bioaerosol composition found in Athens' urban air by DNA barcoding. There are currently limitations in establishing a direct link between fungal exposure and health effects due to shortcomings of existing sampling and analysis methods, among other reasons. New sampling technologies and molecular techniques can achieve a better understanding of this link. We collected airborne samples using Rutgers Electrostatic Passive Sampler (REPS). We studied the taxonomy, diversity, and frequency of captured airborne fungal particles by extracting and purifying fungal DNA present in samples and then sequencing it. Four sampling campaigns were conducted in 2019 and one in 2020 at the National Observatory of Athens meteorological and environmental station of Thisseion. Five samples plus two controls were used each time. Sequence analyses are now routine in systematics, taxonomy, and fungi ecology, with the nuclear ribosomal operon being the most frequently targeted genetic region. The variable spacers ITS1 and ITS2, jointly or separately, are often species-specific. Thus, the internal transcribed spacer (ITS) region was our primary choice for molecular identification of fungi. We detected 13 classes of two phyla (Ascomycota and Basidiomycota) and approximately 133.000 OTUs. The dominant classes (>10.000 OTUs) were Dothideomycetes, Malasseziomycetes, Leotiomycetes, and Microbotryomycetes.