#microtwjc 5(?) Microbiology of the built environment - the toilet edition

This weeks microbiology twitter journal club is:

Microbial Biogeography of Public Restroom Surfaces

Gilberto E. Flores¹, Scott T. Bates¹, Dan Knights², Christian L. Lauber¹, Jesse Stombaugh³, Rob Knight^3,4, Noah Fierer^1,5*

1 Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder, Colorado, United States of America, 2 Department of Computer Science, University of Colorado, Boulder, Colorado, United States of America, 3Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, United States of America, 4 Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado, United States of America, 5 Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, United States of America

have a look at the abstract here (emphasis my own):

We spend the majority of our lives indoors where we are constantly exposed to bacteria residing on surfaces. However, the diversity of these surface-associated communities is largely unknown. We explored the biogeographical patterns exhibited by bacteria across ten surfaces within each of twelve public restrooms. Using high-throughput barcoded pyrosequencing of the 16 S rRNA gene, we identified 19 bacterial phyla across all surfaces. Most sequences belonged to four phyla: Actinobacteria,Bacteriodetes, Firmicutes and Proteobacteria. The communities clustered into three general categories: those found on surfaces associated with toilets, those on the restroom floor, and those found on surfaces routinely touched with hands. On toilet surfaces, gut-associated taxa were more prevalent, suggesting fecal contamination of these surfaces. Floor surfaces were the most diverse of all communities and contained several taxa commonly found in soils. Skin-associated bacteria, especially the Propionibacteriaceae, dominated surfaces routinely touched with our hands. Certain taxa were more common in female than in male restrooms as vagina-associated Lactobacillaceae were widely distributed in female restrooms, likely from urine contamination. Use of the SourceTracker algorithm confirmed many of our taxonomic observations as human skin was the primary source of bacteria on restroom surfaces. Overall, these results demonstrate that restroom surfaces host relatively diverse microbial communities dominated by human-associated bacteria with clear linkages between communities on or in different body sites and those communities found on restroom surfaces. More generally, this work is relevant to the public health field as we show that human-associated microbes are commonly found on restroom surfaces suggesting that bacterial pathogens could readily be transmitted between individuals by the touching of surfaces. Furthermore, we demonstrate that we can use high-throughput analyses of bacterial communities to determine sources of bacteria on indoor surfaces, an approach which could be used to track pathogen transmission and test the efficacy of hygiene practices

Here's my thoughts of this (briefly) 

As you can see from this paper certain American restrooms harbour a massive diversity of bacterial species (only bacteria were looked at - I wonder what kind of viruses are here). The majority of which have a strong association with the human species; others come from soil or water. Most of all the diversity of bacteria in the restrooms come from our skin (no surprise there really). 

You might ask: "So what?", "Who cares?" or "Why bother?" 

Is it just because you had access to some fancy machine and 12 bathrooms?

I have to disagree with this viewpoint: This is only the beginning.

 In order to fully understand the microbiology of the built environment and how it effects the human population residing in it we have to start somewhere - and deep sequencing or bacterial diversity is a damn good place t start. (after all we spend the majority of our time in doors - and even when we're outside it will probably be in or in close proximity to major population centres like cities). 

If you don't believe have a look at this site.

This falls into a larger investigation looking into the microbial diversity found across different environments, such as the office (this groups follow on paper) or nursery. We can study 'healthy' environments and we can study 'unhealthy' environments. Potentially there are important microbiological differences between the two. By determining the baseline microbiome we could in theory begin to specifically alter its appearance to enhance the human experience of the build environment for health, environmental or economic reasons.