Not about microbes but there is an interesting article at Smartplanet on office environments: Office work increases toxicity in bloodstreams? | SmartPlanet. It would be interesting to see whether these people have altered microbial communities in conjunction with increased toxins.
We’ve posted in the past (here, here, here, and here) about some of the interesting work taking place at the BioBE Center regarding microbial community structure in health-care facilities. Today a paper on this topic came out in the ISME Journal.
This paper is certainly worth a read for anyone interested in the microbiology of the built environment. In particular they show that microbial community structure depends largely on the type of ventilation present in a room. Furthermore, they show that the microbial community present in a mechanically vented room has lower diversity than rooms with open windows or the outside air… and that lower diversity is comprised largely of human-associated microbes.
Here’s the 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.
There has been a nasty min epidemic at a hospital in Belfast: Bacteria in baby unit traced to sink taps – The Irish Times – Wed, Jan 25, 2012. It appears to have been traced to a water tap. Just a mini reminder that we need to learn more about the biogeography of microbes in the built environment. Plus, this helps point out something I have been meaning to write about more here – just because I am a critic of studies that find microbes in buildings and immediately think we should kill them all – does not mean that I think all microbes in buildings are good. There are plenty of nasties out there.
UPDATED AGAIN: For those funded by the Sloan Foundation Program in Microbiology of the Built Environment there will be a workshop for all grantees in Boulder May 31 and June 1.
Apologies for the earlier incorrect posting with dates of May 24-25. The perils of blogging while hosting a meeting … I posted before the dates had been finalized.
Well, Legionnaires disease is not pleasant by any stretch of the imagination. And this latest report is certainly a bit disturbing: Hospitals water wall source of Legionnaires Disease – Health – CBC News.
But to me, the reaction to this is a bit much. According to the news story there are now two – count ‘em – two – reports of Legionnaire’s disease coming from water features at hospitals. Sure – that is a bad thing. But counting is not a measure of risk. How many hospitals have such features? And how many cases of Legionnaire’s show up when one does not have a water feature? And do water feature’s help in some way (emotionally, or from a microbial diversity point of view, or something). I am not saying water features are a good thing – but it drives me absolutely crazy when we attempt to sterilize our lives – literally and figuratively – all in the name of killing bad germs.
Fortunately the story does at least hint at some complexity here – and ends with a quote that seems more reasonable:
“There are, I think, good reasons why people like water features,” she says. “But there are also good reasons why we don’t have them in hospitals.”
I am reserving judgement on this. Yes I think hospitals should be safe places. But I want to treat a hospital as a complete system – an ecosystem of sorts. And I just do not think one vector – the presence of breeding grounds for Legionella bacteria – should have too much weight.
Just a quick one here — been pointed to the existence of a “self-sterilizing” keyboard (e.g., Brier Dudleys Blog | FDA OKs Vioguards germ-killing keyboard | Seattle Times Newspaper.) from a company called Vioguard. Clearly keyboards could be a “breeding” ground for nasty microbes so cleaning keyboards, especially those used in hospitals, seems like a good idea. This keyboard works by retracting into a drawer and then exposing the keyboard to UV irradiation. UV is a good way to kill microbes (and other organisms) so this is not a totally crazy idea. One major issue I have with this is that I see nothing in their literature or anywhere about the possibility of selecting for UV resistant organisms, which is known to occur when organisms are exposed to cycles of UV irradiation. So while this keyboard may work well when you first set it up, it may become less efficient over time. Not saying it is a good or a bad idea per se – but any time one exposes microbes to a stress (e.g., antibiotics) you have to worry about resistance emerging …
The driving force behind much of the new research in the microbiology of built environment is the Alfred P. Sloan Foundation which is funding a large variety of research projects, as well as microBEnet.
For more information on their program, accomplishments to date, and goals for the future check out this written interview with Paula Olsiewski, the program director.
Well, normally I find popular press stories about getting rid of dust and bacteria to be mostly fear mongering. But this article from WebMD (which much of the time I have complaints about) actually seems worth a look: Are Vacuum Cleaners Bad for Your Health?. The article discusses in part new work from Australian researchers on indoor air quality and vacuuming. The paper is from Environmental Science and Technology: Vacuum Cleaner Emissions as a Source of Indoor Exposure to Airborne Particles and Bacteria. Environ. Sci. Technol., 2012, 46 (1), pp 534–54. DOI: 10.1021/es202946w. The article is currently freely available though I am not sure if that is permanent or not.
These are the vacuums they assessed: (see supplemental material for more detail)
They then collected and/or analyzed particles and bacteria coming out of the vacuums. Bacteria were analyzed using culture independent methods (i.e., rRNA PCR) to quantify total bacteria in the sample (in essence qPCR).
There is a LOT of information in the paper on particles and since I am no particle expert I suggest if you are interested you read the paper. In regard to bacteria, the authors state
We observed mean bacteria emission rates from cold and warm vacuums between 0 and 7.4 × 105 bacteria min^-1. Bacteria emissions were poorly correlated with those of particles and also vacuum temperature, price, and age. ERs of bacteria from cold and warm vacuums were not correlated. There was no apparent relationship with the presence of an exhaust HEPA filter or estimated dust content (percent full) of the container or bag. Interestingly, the bacteria content of the dust collector was poorly correlated with bacteria emissions from cold and warm vacuums.
Our results suggest that different factors are responsible for emission of particles and bacteria across the vacuums we tested. Moreover, the bacteria content of dust in the bag or chamber appears to bear little relation to that in emitted air, indicating that a vacuum containing dust with low bacteria content will not necessarily emit fewer bacteria and lead to a lower exposure than a vacuum with a higher bacteria load in the dust bag.
Vacuum emissions are a potential mechanism of spread of Salmonella spp.(6-9) Other bacteria acquired from household dust, such as Clostridium botulinum,(32) could also be disseminated by vacuum cleaners. Both of these pathogens pose the greatest risk to infants. The role of vacuums in spreading pathogenic bacteria or antibiotic resistance genes and the extent to which they may be implicated in transmission of infections are unclear. Our results provide initial evidence on which to base more expansive follow-up studies of vacuum bacteria emissions and can also be used to model indoor bioaerosol exposure.
And then they conclude
Emissions of particles and bacteria from vacuum cleaners are highly variable, and this is not easily ascribed to the potential determinants we assessed. They are a source of indoor exposure to particles spanning a wide size range, although their significance compared to other sources depends strongly on the individual vacuum and the particle size range considered. Bacteria emissions from vacuums have potential to spread infectious or sensitizing aerosols, and additional investigations to more completely define their characteristics are warranted. Future studies that aim to address the issues raised in this paper will help to further clarify the role of vacuums in human exposure to biological and nonbiological aerosols indoors.
The paper is worth a look.
The Washington Post reports that Legionnaire’s bacteria found throughout Hong Kong’s new government headquarters. This article reminds me of something I have been meaning to post here previously. I think one of the best ways to get the government here in the US to think more about microbes in the built environment would be to survey the microbes in various government buildings. I think it actually would also possibly spark some interest from the public (e.g., if we surveyed the White House for example). I wonder – if one took a tour of the White House would it be “legal” to collect some microbial samples during the tour?
Seems like every day there is a new report of “bacteria and germs found” somewhere in the household. Todays report tells us that: Bacteria can thrive on paper towels, says study – HealthPop – CBS News.
Yes, that is right – microbes – which are tiny and live EVERYWHERE – can in fact be found on paper towels that have not been sterilized. Shocking. Just make sure to spray your paper towels with antibiotics and we will all be safe. And now back to your regularly scheduled program.
 This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License. Boston Skyline: Arvind Balaraman / FreeDigitalPhotos.net,ISS: NASA,Heater: CDC, Mold: EPA, Staph: Janice Haney Carr, CDC |
