Assessing the aerodynamic diameters of taxon-specific fungal bioaerosols by quantitative PCR and next-generation DNA sequencing

Abstract

Aerodynamic diameter is an important determinant of the physical processes that act upon airborne fungi. Processes include gravitational settling, respiratory deposition, penetration into buildings, resuspension from surfaces into air, and long-range transport. This study combined next-generation DNA sequencing (NGS) with quantitative PCR (qPCR) to evaluate diverse, taxon-specific, fungal aerodynamic diameters from bioaerosol samples. The accuracy of the method was demonstrated by comparing geometric mean aerodynamic diameters of selected taxa produced by the NGS-based method to the diameters produced by taxon-specific qPCR (r=0.996). Geometric means (dg) and geometric standard deviations (σg) of aerodynamic diameters were characterized for more than 50 fungal taxa, spanning 55 genera, 9 classes, and 2 phyla. The results reported in this study demonstrate the robust nature of this method, provide novel insights into aerodynamic properties of diverse airborne fungal species, and potentially enable a better accounting of taxon-specific fungal fate and exposure both in indoor air and in the atmosphere.