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Science and Innovations

NAU Study: Cities Have Unique Microbial Fingerprints

Cache Gibbons and Samantha Veysey

The microbial communities in offices are generally similar—as long as those offices are in the same city. But every city has its own microbial fingerprint, according to a study led by Northern Arizona University.

Biologists sampled offices in Flagstaff, San Diego and Toronto. They used DNA sequencing to identify microbes on the floors, walls and ceilings.

Each city had a unique microbial community – so unique the scientists could predict the origin of an unlabeled sample just by looking at the microbes. 

John Chase is the lead author of the NAU study. “My working hypothesis would be that the differences we’re seeing in cities are being driven by the microbes in the environment around the city,” he says. “I would expect that any city with different climates would have sort of a unique microbial fingerprint.”

People drive the composition of office microbes as well. A quarter of the microbes sampled came from human skin.

Chase suspects offices have mostly dead or dormant microbial communities, because the microbes didn’t react to changes in humidity or temperature during the experiment. NAU scientists plan to test that hypothesis next.

Credit John Chase
Microbe sampling plates attached to the floor, wall and ceiling of a Flagstaff office. Each plate has different material (carpet, drywall and tile).

Melissa joined KNAU's team in 2015 to report on science, health, and the environment. Her work has appeared nationally on NPR and been featured on Science Friday. She grew up in Tucson, Arizona, where she fell in love with the ecology and geology of the Sonoran desert.
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