Targeted gene amplicons of fungi raw sequence reads

Inhalation of airborne fungi is known to cause of respiratory illnesses such as allergy. However, the associations between exposures and health outcomes are largely unclear in part due to lack of knowledge about daily life fungal exposures. This study aimed at comparing fungal communities and concentrations in indoor, outdoor, and personal air by using DNA-based methods such as high-throughput sequencing (HTS) and quantitative PCR (qPCR). Five sets of concurrent indoor, outdoor, and personal air samples were collected, and each set lasted for a duration of 4 days. Our sequencing analysis showed the species richness was larger in personal air than in indoor air for four out of the five sets, indicating people are exposed to the outdoor species that are not present in indoor air. The personal-indoor (P/I) and personal-outdoor (P/O) ratios of total fungi were 1.2 and 0.15, respectively, suggesting personal exposures to total fungi are better represented by the indoor concentrations than by the outdoor concentrations. However, the ratios were taxon-dependent, reminding the complexity of generalizing personal exposures to the diverse kingdom Fungi. The study reported here demonstrates the HTS/qPCR method was useful for assessing taxon-specific fungal exposures, which might not be well characterized by conventional non-DNA-based techniques.