Teams of researchers and volunteers fanned out throughout the mass transit techniques of 60 cities, gathering hundreds of samples from 2015 to 2017. They swabbed a wide selection of surfaces, together with turnstiles, railings, ticket kiosks and benches inside transit stations and subway vehicles. (In a handful of cities that didn’t have subway techniques, the groups centered on the bus or practice system.)
The scientists’ subterranean sampling expeditions typically attracted consideration. Some commuters grew so curious that they joined the volunteer swabbing corps, whereas others insisted that they completely didn’t need to know what was residing on the subway poles. Passengers often misunderstood what the researchers had been doing with their tiny swabs. “One man effusively thanked us for cleaning the subway,” Dr. Mason stated.
The researchers additionally collected air samples from the transit techniques of six cities — New York, Denver, London, Oslo, Stockholm and Hong Kong — for a companion paper on the “air microbiome” that was published on Wednesday in the journal Microbiome.
“This is huge,” stated Erica Hartmann, a microbiologist at Northwestern University who was not concerned within the examine. “The number of samples and the geographic diversity of samples — that’s unprecedented.”
Then the workforce extracted and sequenced the DNA from every pattern to determine the species it contained. In complete, throughout all of the floor samples, they discovered 4,246 recognized species of microorganisms. Two-thirds of these had been micro organism, whereas the rest had been a combine of fungi, viruses and different kinds of microbes.
But that was just the start: They additionally discovered 10,928 viruses and 748 varieties of micro organism that had by no means been documented. “We could see these were real — they’re microorganisms — but they’re not anywhere in any database,” stated Daniela Bezdan, the previous government director of MetaSUB who’s now a analysis affiliate on the University Hospital Tübingen in Germany.
The overwhelming majority of these organisms most likely pose little danger to people, specialists stated. Nearly all of the brand new viruses they discovered are prone to be bacteriophages, or viruses that infect micro organism, Dr. Danko stated. Moreover, genetic sequencing can not distinguish between organisms which might be useless and people which might be alive, and no setting is sterile. In truth, our our bodies depend on a wealthy and dynamic group of microbes with a purpose to perform correctly.