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OCCRI Mini-Conference

We attended the Oregon Climate Change Research Institute Mini-Conference at Oregon State University on 10/18/17. This half-day event featured 4 minute lightning talks on a broad gamut of climate change related topics, including presentations on atmospheric modeling, meteorology, ocean and tidal science, vegetation impacts, public health, and legal efforts, and featuring an extended “conversation” on ethical and moral issues. Jeff Kline of BioBE presented a short talk titled “Consuming and Producing Climate change Research” which covered the building science and microbial ecology aspects of our work.

Combining multiple sequencing runs: heterogeneity spacers

We do a lot of Illumina-based metabarcode sequencing here at the BioBE center. Sequencing is getting cheaper, and the amount of data you can get from a sequencing run continues to increase, but not at the same rate: it is now becoming more and more common to sequence samples across multiple sequencing runs, because a single run does not provide the necessary sequencing depth.

The field, as a whole, is still trying to work out how combine samples from different sequencing runs: because the error rates and read distributions tend to be specific to a given sequencing run, it can be difficult to distinguish between run effects and biological effects.

We’ve recently run across an interesting case, while working to improve our bioinformatics pipelines.

It is common for sequencing facilities to spike in Phi-X DNA to add heterogeneity to the library being sequenced; this heterogeneity prevents synchronous fluorescence from any given base overwhelming the sensor (Phi-X reads are removed bioinformatically, generally by the sequencing facility). There is, however, a more sequencing-efficient way to introduce heterogeneity into your library: variable length spaces between the Illumina adapter and the target sequence. This method doesn’t “waste” sequencing on Phi-X, but still handily prevents synchronous fluorescence. The problem is, sometimes those spaces may not be fully removed before data processing.

In collaborating with colleagues to test various options for merging data from distinct sequencing runs, we were working with some problematic data that included samples re-sequenced in two different Illumina MiSeq runs. We discovered that they had such heterogeneity spaces that had not been removed by the sequencing facility. This didn’t matter at all when processing with QIIME and uclust, because the 97% OTU radius was enough to “lump” all of the spacer sequences into the same OTU, but when working with denoising tools that infer exact sequence variants (ESVs), like DADA2, it altered the ability to recognize that the dominant sequences from the same sample in the two different runs were the same.

Alignment showing heterogeneity spacers, and the artificial variation which that the may introduce.

There are several potential solutions to this problem, but the best one is to always make sure you understand your data fully, and remove any potential sources of artificial variation before inferring sequence variants or picking OTUs. Usually, that means searching for and removing the PCR primers from each sequence, along with any sequence behind them — there are many programs out there with this functionality, including the FastX toolkit, trimmomatic, and cutadapt. If you’re sequencing a variable length region, like the internal transcribed spacer (ITS) of the ribosomal DNA, this also has the benefit of removing artificial variation introduced by sequencing past the primer on the other side of the short amplicons.

Another potential solution if you’re using DADA2 is to use “100%” OTU clustering (that is collapsing all sequences that differ only be length into the same inferred variant). There is, conveniently, an option baked into dada() for that: collapseNoMismatch = TRUE. The DADA2 pipeline also did a much better job of recognizing that different sequences with artificial variation were actually the same when using pool = TRUE, although pooling all samples for sequence inference is likely too computationally intensive to be a viable solution.

Additionally, Paul McMurdie points out that we can look for irregularities early on with DADA2:

Another way to note this early in your process is to check that the error rates look reasonable for your platform/amplicon, e.g. if you had previous successful runs for that amplicon and seq platform, you could check that the error profiles are not wildly different. If they are, you usually have a problem with trimming.

I am, however, not able to see a clear signal of the heterogeneity spacers in the error profiles for this data. It may vary with the length and variation within the spacers — I’ll surely be adding an error profile check to my standard workflow, though.

After removing the primers and spaces, we get much better agreement between sequencing runs (although we still get 45–65% of ESVs in only one run or the other). We’re still investigating this particular issue: you can follow the ongoing discussion (and contribute!) on the DADA2 GitHub page.

 

Design Champs

Last week, the staff of the Biology and the Built Environment Center presented cutting-edge science from the Center and beyond to a group of interested practitioners. The Design Champs webinar series is intended to communicate new scientific advances in the field of indoor microbial ecology research to architects, engineers, and other interested parties. For this second seminar in the series, we had representatives in attendance from:

  • ZGF Architects
  • HOK
  • Thornton Tomasetti
  • SRG Partnership
  • Hacker Architects

The group was lively, and participated in a active discussion of some of the science we’ve been doing at the BioBE Center lately. In particular, we briefed them on some thoughts on hygiene that we’ve been having lately, and then discussed how that might impact the way we think about design; next, we discussed the human microbial cloud, tying the idea into the discussion of hygiene and design; this led smoothly to a discussion of some of our most recent work, focusing on the transmission of microbes to the human skin microbiome. After discussing how hygiene serves as a conceptual frame for understanding both of those studies, we went on to talk about antimicrobial compounds in built environments, and how that relates to the spread of antibiotic resistance genes.

The webinar finished with a preview of related new work — a much larger study on antibiotic resistance genes in indoor microbiota, conducted across dozen of gyms in the Pacific Northwest, and including the synergistic use of next-generation sequencing for metabarcoding and metagenomics, and targeted LC-MS/MS and intensive antibiotic-resistance culture assays in association with colleagues at Northwestern in Chicago.

Round up of ESA conference

The 2017 ESA meeting in Portland, OR, which took place August 6-11, created a flurry of imagination here in Eugene: Roo Vandegrift left with a large hash of approximately 275 live-tweets, Sue Ishaq left with a jumbled pile of hastily scribbled notes in the program book margins, a few of which she has expanded upon, and Ashkaan Fahimipour went away with the inscrutable expression of a mathematical modeler visualizing complex networks in their head. All three presented some of their recent or ongoing work, along with a number of other BioBE members and friends from the UO Institute of Evolution and Ecology.

The meeting started out with a number of engaging science activities, including the Field-to-Collection BioBlitz, which brought conference participants to Forest Park in Portland to collect biological samples for identification and curation. Forest Park is the largest urban forest in the United States, and the biological specimens collected will shed light on the number and types of diversity found there, as well as indicate the success of urban forests at harboring a sustainable level of biodiversity.

The plenary speech was given on Sunday evening, officially opening the conference, and presentations kicked off bright and early on Monday morning. Of the BioBE team, Roo was first to give a presentation on Monday afternoon, on a project led by the recently-defended Dr. Ashley Bateman for her dissertation: Moving Microbes: the dynamics of the skin microbiome in response to environmental exposures. (Revised; listed as “The built environment as a reservoir for transmission and colonization of the skin microbiome.”)

 

 

Erica Hartmann, Assistant Professor at Northwestern University, presented on Tuesday with a compelling talk on the importance of limiting antimicrobial chemicals in synthesized products: Antibiotic resistance and antimicrobial chemicals in the built environment. Antimicrobial chemicals are pervasive in the built and outdoor environments, much more than we realize, yet we have little knowledge of their long-term effect on microorganisms or how this might feed-back onto human health. The full publication can be found here.

Gwynne having a delightful time at her poster.

On Tuesday evening, doctoral candidate Gwynne Mhuireach presented her poster on Fine-scale urban vegetation patterns shape airborne microbial community composition.

Wednesday evening, Sue presented some preliminary data on a project she is finishing up from her post-doc: Soil bacterial diversity in response to stress from farming system, climate change, weed diversity, and wheat streak virus (poster). A more detailed description of her previous work can be found here.

Ashkaan gave a presentation on Thursday on The dynamics of food web assembly: Structure, stability, and trophic cascades.  The study explored how empty ecosystems acquire new species, how the food web develops over time, and how the trophic niches of those colonists can determine the total diversity of the ecosystem or weather disturbances. The large meeting room was well-attended, despite the low total abundance pictured- ecologists don’t seem to like to sit in the front rows.

 

In between our presentations, we filled our days by attending other talks and posters, networking events, and daydreaming about our own science.  We took away valuable perspectives on newly discovered results, considerations for data analysis, or the dynamics of ecological systems, which can be incorporated into our own work to improve how we think about indoor systems and approach problem solving.  You never know when a presentation on shower heads, baboons, or dormant amoeba might give you an idea which will change the way you think.

Looking ahead, we are anticipating attending a number of conferences on microbiology, air quality, building health, architecture, and ecology over the next year. Here are a few of the meetings that are already on our calendars:

Daylight Exposure & Microbial Communities Indoors

The microbiome and its relevance to healthy environments was of critical interest at the Health Energy Research Consortium.  Ashkaan Fahimipour, presented BioBE‘s recent investigations in microbial communities and exposure to daylight.

Humans spend most of their time indoors, exposed to bacterial communities found in dust. Understanding what determines the structure of these communities may therefore have relevance for human health. Light exposure in particular is a critical building design consideration and is known to alter growth and mortality rates of many bacterial populations, but the effects of light on the structure of entire dust communities are unclear.

We performed a controlled microcosm experiment designed to parse the effects of filtered solar radiation on the structure of dust microbial communities.

We report that exposure to light per se has marked effects on community diversity, composition and viability, while variation in light dosage or particular wavelengths experienced are associated with nuanced changes in community structure. Our results suggest that architects and lighting professionals designing rooms with more or less access to daylight may play a role in shaping bacterial communities associated with indoor dust.

This post is part of a blog series sharing information covered at the Health Energy Research Consortium in Portland, OR May 4-5, 2017. View the original post on the ESBL blog.

2017 AIA Design & Health Research Consortium Convening

On March 21-22, the BioBE Center team took to Detroit to present “Biology & Buildings: How Indoor Environments Affect Human Health” to the American Institute of Architects Design & Health Research Consortium.  We were encouraged to see the diversity of research blooming at our fellow ACSA schools of architecture. For example, Joseph Kennedy from the NewSchool of Architecture & Design presented fascinating work on natural building materials in a panel discussion with members of the BioBE team. Bita Kash from Texas A&M University presented excellent work on integrating health and design, discussing ideas of fundamental adjacencies in the design process. Every panel was excellent, and the broad concern for integration of empirical methods to design evaluation was wonderful to see.

Most interesting was to learn from leading architecture firms about how they integrate research into their design practices and how they have developed funding models to support this research.  Upali Nanda (@upalinanda) of HKS Architects (Houston) talked about the importance of pooling research resources and openly sharing new knowledge in order to more rapidly progress the field and avoid redundancy.  Jeri Brittin, Director of Research at HDR Architects (Omaha) eloquently described how the research design process shares similarities with the building design process and how she has effectively used this analogy to explain the value of a rigorous research design process to firm decision makers.  Robert Phinney (@rsphinney), Sustainable Design Director at Page Architects (Washington DC), described the uphill climb that many firms face when trying to meaningfully integrate original research into the building design practice, stressing that measurable outcomes and financial metrics dominate the discourse.  What was most encouraging was that all three firm leaders described the immense value to their firms and clients of maintaining a tight relationship with university research and how rewarding it can be to work with academics to leverage their technical skills to help overcome the “pain points” facing their practice.  We couldn’t agree more!

Some of our most rewarding research has been closely linked with practical industry needs. However, there are some challenges that we face in the academy when integrating our work with industry objective.  First and foremost, is to ensure academic integrity when creating the research design to avoid real or perceived biases associated with industry engaged research.  Without this, the research has no value to industry or to science.  Other important considerations is to be nimble enough to complete the research at the “speed of business” and to work out possible concerns with intellectual property.  All of these, and other concerns, can be, and have been overcome.  The result in an opportunity to bring the leading scientific processes and utmost rigor to important problems that face society.  Industry partners can help to focus academic research and help it gain traction to make greater impact more rapidly.  It is for these reasons that we have launched a new industry engagement model here at the University of Oregon.

Mhuireach Awarded A&AA Dissertation Fellowship 2017-2018

Congratulations to Gwynne Mhuireach for winning a Dissertation Fellowship from the School of Architecture & Allied Arts at the University of Oregon!  Her working dissertation title is: Toward a Mechanistic Understanding of Relationships Between Airborne Microbial Communities and Urban Vegetation: Implications for Urban Planning and Human Well-being.  Mhuireach holds an M.Architecture (2012) from the University of Oregon and a B.S. in Biology (Ecology and Evolution Track, 1999) form the University of Washington. She is presently a Graduate Research Fellow at the Energy Studies in Buildings Laboratory and BioBE Center at University of Oregon.  Her anticipated graduation is June 2018.

Recent publication: Urban greenness influences airborne bacterial community composition

Dissertation Abstract: Variation in exposure to environmental microbial communities has been implicated in the etiology of allergies, asthma and other immune-related disorders. In particular, exposure to a high diversity of microbes during early life, for example through living in highly vegetated environments like farms or forests, may have specific health benefits, including immune system development and stimulation. In the face of rapidly growing cities and potential reductions in urban green space, it is vital to clarify whether and how microbial community composition is related to vegetation. The purpose of my proposed research is to identify plausible but under-explored mechanisms through which urban vegetation may influence public health. Specifically, I am investigating how airborne microbial communities vary with the amount, structural diversity, and/or species composition of green space for 50 sites in Eugene, Oregon. My approach combines geographic information systems (GIS) and remote sensing data with passive air sampling and culture-independent microbial sequencing.

Committee members:

  • Dr. Bart Johnson, Professor of Landscape Architecture (Major Advisor & Committee Chair)
  • Dr. Jessica Green, Professor of Biology (Co-Advisor)
  • Roxi Thoren, Associate Professor of Landscape Architecture (Core Member)
  • Dr. Deb Johnson-Shelton, Education/Health Researcher, Oregon Research Institute (Core Member)
  • G.Z. Brown, Professor of Architecture (Institutional Representative)

 

 

 

Health + Energy Research Consortium

The Biology and the Built Environment Center (BioBE) and Energy Studies in Buildings Laboratory (ESBL) at the University of Oregon, are pleased to announce the launch of the the Health + Energy Research Consortium!  On May 4-5, 2017, in Portland Oregon, we begin our journey to dramatically reduce energy consumption and maximize human health by conducting research that transforms the design, construction and operation of built environments. This collaboration between innovative industry professionals and academic researchers in the disciplines of architecture, biology, chemistry, engineering, and urban design provides sharp focus to a research agenda that will accelerate the impact of key scientific discoveries.  The Health + Energy Research Consortium builds upon the momentum of ESBL and BioBE to create a new, dynamic, and flexible mechanism for the university to engage with industry in joint research and development ventures – providing intellectual space for the meeting of a wide array of disciplines that play integral roles in fostering improved energy efficiency and health outcomes in the built environment.

At the May 4-5 launch event , we will present the vision for the Consortium, solicit feedback about the proposed research agenda, explain and discuss the financial commitments and value proposition associated with Consortium membership, and discuss synergies with potential member organizations’ goals and objectives.  If you are interested in helping us align the Consortium research vision with the challenges that face our built environment and your industry sector, please contact BioBE Director, Kevin Van Den Wymelenberg.

We would like to acknowledge the generous support for the Health + Energy Research Consortium from the Alfred P. Sloan Foundation.  Registration is required, but the event is available at no charge.

EPA Progress Meeting

Jeff Kline presented BioBE’s project, “The Impact of Weatherization on Microbial Ecology and Human Health” at EPA’s Science to Achieve Results (STAR) Indoor Air & Climate Change Progress Review Meeting and Webinar.  The meeting was held in December in Washington, D.C. The presentations will be made available on the meeting website.

 

 

The concept of hygiene and the human microbiome.

Reblogged from MicrobeBE.net.


(This post was written by Roo Vandegrift, at the University of Oregon)

I was recently asked to spearhead the writing of a review centered around the interaction between the concept of hygiene and our increasingly nuanced understanding of the human skin microbiome for the Biology and the Built Environment (BioBE) Center at the University of Oregon.

This review began with an invitation from Dyson to conduct an impartial review of hand drying studies, which have been mired in competing interests and faulty methods. We saw an opportunity to not only provide an unbiased review of the literature, but also to ask a more fundamental question: how should hygiene be defined in light of our evolving perspective of the human and indoor microbiome?  We delivered a brief summary to Dyson (here) and then built upon that work to develop this question.  

As we started digging into the body of literature on hand hygiene, two things struck us as peculiar: the first was that in the hundreds of studies explicitly examining hygiene, the concept was never explicitly defined; the second was that there seemed to be a clear division between skin microbiological investigations coming from clinically and ecologically informed perspectives, with clinical research generally relying on older cultivation-dependent techniques. These two issues became the drivers for our review, and our goal was to provide an explicit definition of hygiene that would help to bridge the gap between the clinical skin microbiology literature and the newer human-associated microbial ecology literature. We were then able to use the body of literature on hand drying as a case-study to examine the implications of using a microbial ecology-based approach to defining hygiene.

You can read the full review as a preprint on bioRxiv now: http://biorxiv.org/content/early/2016/12/20/0957450

You can read the shorter, white page summary of the review on the BioBE blog: https://biobe.uoregon.edu/2016/11/04/cleanliness-in-context

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