We've been hearing a lot lately about how every person hosts their own unique population of viruses and bacteria, known as their microbiome. Well, according to a new international study, the same thing is true of cities.
For the Weill Cornell Medicine-led project, scientists from a variety of institutions collected microbe samples from surfaces in public transit systems and hospitals, located in 60 cities in 32 countries and six continents. A total of 4,728 samples were gathered, over a three-year period from 2015 to 2017.
When those samples were sequenced and analyzed, 4,246 known species of viruses, bacteria and archaea were identified, 31 of which were common to 97 percent of the cities. What's more, a whopping 10,928 viruses and 748 bacteria were discovered, which are currently not present in any reference databases.
Importantly – with the exception of the 31 core species – it was found that most of the microbes were distinct to specific cities. As a result, the scientists were able to identify telltale microbiome signatures that were unique to each community.
"Every city has its own 'molecular echo' of the microbes that define it," says the study's senior author, Weill Cornell Medicine's Prof. Christopher Mason. "If you gave me your shoe, I could tell you with about 90 percent accuracy the city in the world from which you came."
The scientists are now studying how COVID-19 and its associated lockdowns have affected the makeup of the microbiomes. It is hoped that among other things, the research may ultimately lead to an improved ability to detect outbreaks in urban environments, along with aiding in the development of new antimicrobial drugs. There could presumably also be applications in the field of forensics.
A paper on the research was recently published in the journal Cell.
Sources: Cornell University, University of Maryland School of Medicine via EurekAlert
