Microbiota of the indoor environment: a meta-analysis

Abstract

BackgroundAs modern humans, we spend the majority of our time in indoor environments. Consequently, environmental exposure to microorganisms has important implications for human health, and a better understanding of the ecological drivers and processes that impact indoor microbial assemblages will be key for expanding our knowledge of the built environment. In the present investigation, we combined recent studies examining the microbiota of the built environment in order to identify unifying community patterns and the relative importance of indoor environmental factors. Ultimately, the present meta-analysis focused on studies of bacteria and archaea due to the limited number of high-throughput fungal studies from the indoor environment. We combined 16S ribosomal RNA (rRNA) gene datasets from 16 surveys of indoor environments conducted worldwide, additionally including 7 other studies representing putative environmental sources of microbial taxa (outdoor air, soil, and the human body).ResultsCombined analysis of subsets of studies that shared specific experimental protocols or indoor habitats revealed community patterns indicative of consistent source environments and environmental filtering. Additionally, we were able to identify several consistent sources for indoor microorganisms, particularly outdoor air and skin, mirroring what has been shown in individual studies. Technical variation across studies had a strong effect on comparisons of microbial community assemblages, with differences in experimental protocols limiting our ability to extensively explore the importance of, for example, sampling locality, building function and use, or environmental substrate in structuring indoor microbial communities.ConclusionsWe present a snapshot of an important scientific field in its early stages, where studies have tended to focus on heavy sampling in a few geographic areas. From the practical perspective, this endeavor reinforces the importance of negative “kit” controls in microbiome studies. From the perspective of understanding mechanistic processes in the built environment, this meta-analysis confirms that broad factors, such as geography and building type, structure indoor microbes. However, this exercise suggests that individual studies with common sampling techniques may be more appropriate to explore the relative importance of subtle indoor environmental factors on the indoor microbiome.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-015-0108-3) contains supplementary material, which is available to authorized users.

One Health Relationships Between Human, Animal, and Environmental Microbiomes: A Mini-Review

“…Applying the One Health approach to the microbiome requires examination of both pathogenic and non-pathogenic microbial transfer between humans, animals, and the environment (11–13). These transmission relationships are shown in Figure 1.…”

Determinación de la calidad bacteriológica del aire en un laboratorio de microbiología en la Universidad Distrital Francisco José de Caldas en Bogotá, Colombia

“…Por otro lado, el género Micrococcus hace parte de la microflora cutánea que ha sido aislado del aire y del suelo (20). Así mismo, los géneros Streptococcus y Corynebacterium hacen parte de la flora normal de la piel (21).…”

“…En cuanto a las bacterias Gram negativas, las bacterias pertenecientes a las familia Enterobacteriaceae están también relacionadas con la presencia de los humanos en los ambientes internos y se han encontrado por ingreso desde ambientes externos (21). Este mismo comportamiento se ha determinado para especies de Acinetobacter y Pseudomonas que fueron aisladas de ambientes internos en la Universidad de Murcia, en España, del aire en zonas de la Facultad de Biología (8), géneros que fueron aislados por Toloza-Moreno et al (13) en el archivo central de la Universidad Pedagógica y Tecnológica de Colombia.…”

“…Esta clasificación de la OMS (22) por grupos de riesgo se utiliza exclusivamente para el trabajo de laboratorio y supone un peligro relativo. El laboratorio de microbiología de la Facultad del Medio Ambiente y Recursos Naturales de la Universidad Distrital se clasifica en el nivel básico de bioseguridad 1, enseñanza básica e investigación, donde solo se requiere de equipo de seguridad, y el trabajo se lleva a cabo en mesa de laboratorio al descubierto (21). La presencia de las bacterias en el aire indica su manejo en la prácticas académicas, en investigación o su introducción a través de las personas, o del aire exterior.…”

Bedroom Allergen Exposure Beyond House Dust Mites

“…Exposures show great variation by geographic and climatic region, while residential fungal exposures often reflect outdoor taxa, albeit at lower levels [138–140]. Despite the strong effects of outdoor characteristics (e.g., vegetation, urbanization), fungal exposure profiles in the home are also affected by housing characteristics and occupants’ behavior [139, 141–143].…”