American Association for Aerosol Research - Abstract Submission

AAAR 38th Annual Conference
October 5 - October 9, 2020

Virtual Conference

Abstract View


Correlations of Fluorescent Aerosol Cytometry with Genomics and Mycometry Distinguish Significant Reductions in Airborne Fungal Loads Following Large School Renovations

MARINA NIETO-CABALLERO, Odessa M. Gomez, Richard Shaughnessy, Mark T. Hernandez, University of Colorado Boulder

     Abstract Number: 108
     Working Group: Bioaerosols

Abstract
Real-time fluorescent aerosol cytometry (InstaScope, DetectionTek, CO) was compared to concurrent recovery of airborne β-N-acetylhexosaminidase (Mycometer air, Mycometer Inc., FL) to assess the respective ability of these methods to detect significant changes in airborne loads of fungal biomass in response to building renovations. Condensation growth tube collection, or CGTC, (Spot Sampler, Aerosol Devices, CO) was used to concurrently collect aerosol from the renovated schools in order to characterize airborne genetic material with two different approaches: (i) quantitative polymerase chain reaction (qPCR), and (ii) high throughput sequencing (HTS). These simultaneous collocated aerosol measurements, targeting airborne fungal concentrations, were acquired from more than 60 occupied classrooms in 26 different public schools. Composite, site-randomized observations were acquired prior to, and immediately following, major building renovations. As judged by ANOVA and Spearman’s ranking, a statistically significant association was observed between direct fluorescent aerosol cytometry counts and biochemical (β-N-acetylhexosaminidase) measurements, which detected significant reductions in airborne fungal loads following building renovations. Gene copy numbers estimated by quantitative polymerase chain reaction (qPCR) of the DNA extracted from the CGTC air sampling, suggested that some of the airborne fungi recovered possessed a wide range of gene copies, corresponding to a universal 18S rRNA gene as an amplification target. High throughput “shotgun” sequencing was also performed on the DNA extracted from CGTC air samples. With aerosol sample times under 30 minutes, these results show that the CGTC sampling can recover and preserve enough airborne microbial DNA for high-fidelity metagenomic analyses in sampling durations less than an air change rates typically observed in K-12 classrooms.