Identifying Fungal Pathogens in the Air of Atlanta

Abstract

The atmosphere is a vastly understudied habitat for airborne microbial communities invisible to the naked eye. Very little is known regarding the microbial composition of these airborne communities and how composition varies across different meteorological conditions. Even less is known regarding the potential impact of these bioaerosols on human health. Capturing a representative sample of the microbes present in the air is technically challenging, and traditional culture-based methods often capture <1% of the total airborne cells. To circumvent these limitations of culturing, this study employed nucleic acid-based analysis of microbial cells recovered directly from the sample filter. The goal of the study was to provide snapshots of the airborne microbial community in Atlanta’s air throughout a time series of two consecutive years. Polymerized chain reaction (PCR) was used to amplify the highly conserved ITS regions of fungal genomes. The resulting sequences were analyzed using established bioinformatics pipelines in order to identify the microbes present. The analysis revealed several fungal species representing common pathogens of plants to be present in these samples as well as species associated with respiratory events in humans with asthma or other upper respiratory conditions. Future work to expand the time series and the breadth of the study to include viruses could answer the epidemiological mystery surrounding the cause of seasonality in respiratory infections (e.g., whether or not they are airborne), and it could build a more complete picture of the inherent health risks of breathing open air.