Architectural design influences the diversity and structure of the built environment microbiome

Abstract

Buildings are complex ecosystems that house trillions of microorganisms interacting with each other, with humans and with their environment. Understanding the ecological and evolutionary processes that determine the diversity and composition of the built environment microbiome—the community of microorganisms that live indoors—is important for understanding the relationship between building design, biodiversity and human health. In this study, we used high-throughput sequencing of the bacterial 16S rRNA gene to quantify relationships between building attributes and airborne bacterial communities at a health-care facility. We quantified airborne bacterial community structure and environmental conditions in patient rooms exposed to mechanical or window ventilation and in outdoor air. The phylogenetic diversity of airborne bacterial communities was lower indoors than outdoors, and mechanically ventilated rooms contained less diverse microbial communities than did window-ventilated rooms. Bacterial communities in indoor environments contained many taxa that are absent or rare outdoors, including taxa closely related to potential human pathogens. Building attributes, specifically the source of ventilation air, airflow rates, relative humidity and temperature, were correlated with the diversity and composition of indoor bacterial communities. The relative abundance of bacteria closely related to human pathogens was higher indoors than outdoors, and higher in rooms with lower airflow rates and lower relative humidity. The observed relationship between building design and airborne bacterial diversity suggests that we can manage indoor environments, altering through building design and operation the community of microbial species that potentially colonize the human microbiome during our time indoors.

Biogeographic patterns in below-ground diversity in New York City's Central Park are similar to those observed globally

“…Although we found a high degree of overlap in the composition of communities from Central Park and those from other biomes, there are clearly numerous taxonomic groups, which differ in abundance between Central Park and other biomes. However, one particular group that differed in relative abundance between the two sample sets were those phylotypes whose sequences were close matches to human pathogens [35,36]. While sequences matching potential human pathogens were relatively rare in all soils, humanassociated potential pathogens were over two times more abundant in the Central Park soils ( p , 0.001) (electronic supplementary material, figure S5a).…”

“…We used a number of metrics to compare soil biodiversity between the Central Park and global soil sample sets. The relative abundance of potentially pathogenic bacteria was calculated following Kembel et al [35]. USEARCH [34] was conducted comparing each phylotype with a reference database of bacterial strains that are known human pathogens [36].…”

The bacterial composition of ventilation filter dust in Norwegian pre-school nurseries

“…The genera indicated were Micrococcus, Streptococcus, Corynebacterium, Propionibacterium, and Staphylococcus. 14,17,[30][31][32] Sequences classified as Micrococcus and Streptococcus were dominant in exhaust samples making up 16% and 8% of the sequences respectively. Some genera which include primary pathogenic species, such as Legionella sp., Burkholderia sp., Neisseria sp., and Mycobacterium sp.…”

“…Our findings are supported by previous studies which found less chloroplast DNA in mechanically ventilated rooms than those with natural ventilation. 17 Mechanical ventilation systems might then be beneficial to those suffering from pollen allergies. It has been found that HVAC systems equipped with MERV13 filters, the ASHRAE equivalent to F7 filters, effectively reduced indoor levels of common asthma and allergy triggers such as cat allergens and airborne PM 2.5 .…”

Urban stress is associated with variation in microbial species composition—but not richness—in Manhattan

“…Phyla-and class-level abundance was analyzed using analysis of variance with post-hoc Tukey's honest significant difference test. The abundance of potentially pathogenic bacteria was calculated following Kembel et al (2012) and analyzed using a t-test. Indicator family analysis was conducted with 9999 permutations using the multipatt function in indicspecies (Miquel De Caceres R).…”