BioBE’s Dr. Roo Vandegrift will be presenting at the 11th International Mycological Congress, in Puerto Rico July 16-21, 2018!  This meeting is particularly exciting as it will bring together the Mycological Society of America (MSA), the International Mycological Association, the Latin American Mycological Association (ALM), the Puerto Rican Mycological Society (SPM), and the Universidad del Turabo.  Roo presented some work at last year’s Mycological Society of America meeting, as well.  This year, he will be presenting:

683 Shut the front door: seasonal patterns in window operation drive fungal and bacterial community dissimilarity between indoor and outdoor air.

R. Vandegrift1, S.L. Ishaq1, J. Kline1, A. Fahimipour1, J. Stenson1, R. Crowley2, H. Wilson1, D. Northcutt1, E. Hartmann3, D. Johnson-Shelton2, G.Z. Brown1, J. Green1, K. Van Den Wymelenberg1
>1Institute for Health in the Built Environment, University of Oregon, Eugene, OR/United States of America, 2N/A, Oregon Research Institute, Eugene, OR/United States of America, 3Dept. of Civil & Environmental Engineering, Northwestern University, Evanston, IL/United States of America

Abstract
Weatherization typically focuses on air-sealing buildings to reduce energy use, which has the potential to alter indoor microbial communities through reduction of a primary source of indoor microbiota: the outdoors. Indoor sources of microbes may be enriched for human-associated organisms with increased probabilities of potential immune dysfunction and infection. Tightening of the building envelope by weatherization measures may also affect the indoor air quality, as reduced air exchange rates may concentrate harmful pollutants indoors. It is known that ventilation strategy alters indoor microbial signatures, but the role of building operation by occupants has not been well studied. We set out to study the ways that weatherization alters indoor air quality, including the composition and structure of indoor fungal and bacterial communities.

Sixty-six households across the greater Portland, OR, metro area were recruited through our local partners to obtain paired weatherized and comparison homes. For both comparison and treatment homes, we collected data in three core research domains: bioaerosol microbial community composition, air quality and building science, and home occupant behaviour and perception. Briefly, each home was equipped for one week with dual sampling units (one indoors, and one out-of-doors), including standard air quality sensors and settling plates for bioaerosol microbial community sampling. Each home was sampled twice: before and after weatherization, or a similar interval for comparison homes; at each sampling, we administered a survey of home operational behaviours and health indicators to residents. Microbial communities were assessed using standard Illumina metabarcoding methods for bacteria (16S) and fungal (ITS) components; analysis used DADA2, phyloseq, vegan, and codyn in R.

We observed no gross effect of weatherization treatment, indicating that microbiomes of weatherized homes were not more human-associated after treatment. We found that the community dissimilarity between paired indoor/outdoor bioaerosol samples is related to seasonal patterns of window operation, and that the synchrony between indoor/outdoor air quality measures helps explain the dissimilarity in microbial communities. These results, taken together, demonstrate the impact that seasonal choices in home operational mode has on the balance of microbial sourcing, which may play a role in the health of building occupants. While weatherization may impact the air quality and microbial communities of buildings when they are operated in an entirely ‘closed’ mode, the effect of choice of operational mode, which varies seasonally, has by far the greater impact on the indoor microbiota.

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