Thursday, 4 June 2015

World Atlas of Microbiology


Each time inhale, you suck in thousands of microbes. (Yes, even right then. And just then, too.) But which microbes? Scientists mostly assumed that the living components of air—at the tiniest scales, anyway—were the same no matter where you went. Wired reports....

And? Not true, it turns out. Thanks to a 14-month citizen-science project that sampled and analyzed airborne dust around the country, researchers have constructed the first atlas of airborne bacteria and fungi across the continental US. And airborne microscopic life is really diverse.

More than 1,400 volunteers swabbed surfaces in 1,200 houses around the country, focusing on the places people don’t usually clean. The dust there passively collects microbes. In the end those swabs revealed about 112,000 bacterial and 57,000 fungal phylotypes (i.e. familial groups).

Most of these little guys were harmless. The few pathogens and allergens ended up being location-specific. Alternaria, a fungal genus that’s also a common allergen, is ubiquitous but concentrates most in the midwest. The fungus Cladosporium has smaller hotspots scattered all over the country east of Texas, most frequently in the South and Mid-Atlantic. Meanwhile, the bacterial genus Cellulomonas, an normally harmless microbe (but an emerging pathogen according to one study), is much more common in the west.

The two biggest factors that shape this airborne environment, according to study author andUniversity of Colorado microbial ecologist Noah Fierer, are the types of soil and plants that are located in the area (affecting the acidity in the environment), and the climate (humidity, temperature, etc.) Cities, for example, tended to be more like other cities than the rural areas nearby, which Fierer attributes to urban areas tending to plant the same types of trees and flowers and playing host to the same types of wildlife (pigeons, rats, etc).

Fierer isn’t sure how to interpret the new map. He can’t even compare it to historical data; there isn’t any. But with this proof-of-concept in place, Fierer’s team is thinking bigger, planning to put filters on top of cars and drive around to gather air samples across large distances and regions. Ideally that’ll provide some insight into how airborne pathogens affect public health, agriculture and livestock, and wildlife epidemics.

But even that won’t provide more clarity on exactly which microbes you’ve inhaled while reading this. Don’t panic! Deep breath. Or not.

Posted by Tim Sandle

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