We did see some geothermal Phyllis species which can survive on rocks and and hot environments.

We've also seen staphylococcus epidermis.

The most common species was cute back near acne which is something that's a normal skin flora bacteria.

That is really just being shed off of our human bodies into the transit system.

Hello I am Christopher mason, a professor of genomics, physiology and biophysics at Weill Cornell medicine Dr Mason and his team started swapping subway stations in 2013 we set up an app a tracking system.

Developed a protocol and we went and swab every single subway station in triplicate across new york city they're looking to discover and categorize the microbiome found in city subways.

The microbiome is the collection of microorganisms that are either in on or all around you.

And they include bacteria, viruses, fungi, parasites really.

Any little organism that you can't quite see but that has a strong, really powerful feature of mediating health and disease.

There are large cities today where we just don't have a sense of what they look like or even many environments really.

Most of the world's environments.

We don't have a microbial or macroscopic view of the biology that's there's So what do cities actually look like underneath the microscope.

Yeah we normally swab at least three services for each city which is consistently the turnstiles the kiosks and the benches like for example in new york city.

There was geo bacillus thermally of orange which is this really hardy microbes that can survive on rocks and soil and even be desiccated or dried out.

And you know really takes a licking and keeps on ticking and goes on fine.

Like I think new Yorkers, you can see that these really hardy microbes have evolved for the harsh surfaces of the cities in Naples.

We could actually see a lot of mediterranean microbes that have already been found and isolated in the shores of italy or in Greece that could pop up in the cities.

But then we could see other food related microbes that would pop up as well.

So certain kinds of yeast that are associated even with cooking pizza and sort of baking bread we get sometimes pick up more in Naples than in other cities.

That was kind of interesting to see.

We started sampling before during and after the 2016 Olympics.

And we could actually see, you know, this change because a million people swarmed into Rio and started to actually add their microbiome to the cities.

So we've seen the burst of new species emerging as there's a mass increase of humans coming into a city.

And so that disrupted a bit of what the city looks like at the microbial perspective, but it also added some diversity to what's present.

So I actually think that the olympics served not only as a gathering for sports and human endeavors but also gives this interesting addition probiotic to a city essentially in a way.

Tokyo actually has the greatest amount of novel peptides or new sort of biology that we've discovered from any of the cities so far and why this is not entirely clear.

So there's a chance that some of the novel biology that we find there is because it's been so isolated from the rest of the world at earlier centuries.

And so you know that's a hypothesis.

So we have to really test that but we're trying to not really blend microbial ecology.

Modern genetics plus history to get a more comprehensive view of what's happening in the cities and their people.

Tokyo also had a range of neuf ages or these viruses that attack bacteria that we didn't see anywhere else in the world, including some pages that are specific for C.

Acne or very common skin microbe.

So we can actually see that these ecosystems on the surface and on the skin of people in these cities really have their own geography and their own specificity wherever you are in the world.

While each city has a unique microbial footprint dr Mason and his team have identified a core set of commonalities that cities share Across all the systems.

We've analyzed.

There's actually 31 species of bacteria and microbes that are really consistently found.

We find them in 97% of every squad that we take.

So on the one hand, there's this core set of microbes That includes things like you to back your acne or geothermal Phyllis species.

Humans have evolved a tolerance for milk over the past few 10,000 years and this even is reflected in the subway.

Some of the species of lactobacillus are showing up things that you find in milk or in dairy products that we can also see riding on people's hands and skin and then show up in the cities.

We've seen a good number of extremophiles on the subway in particular.

Some that can survive in say the cooling waters of nuclear power plants like Dina caucus radio Duran's is one or other bacteria that are known to survive on stone or survive under high UV light or a lot of radiations.

The subway system and the city's surfaces in rich for and probably select for these hardier microbes that can survive on rough surfaces full of toxins and radiation.

But at the same time we find that there's a lot of species that are very unique to one part of the world that even give us a forensic capacity.

Tell You know, what city did you come from?

And if you look at your shoe for example, we could tell with about 90% certainty where in the world you came from?

Just from the microbes that you're carrying with you with subways teeming with bacteria should commuters start to worry about the microbes will encounter on the subway.

There is some good news in that there is not an avalanche of pathogens waiting to greet you at the subway systems.

A pathogen is an organism that is known to cause an infection and disease.

We've seen no evidence of wealth of harmful pathogens or really even that many opportunistic pathogens in the city centers or transit systems.

But rather have actually seen it seemed to be relatively safe environment.

And even if we look at things like antibiotic resistance or these anti microbial resistance genes, what you'll find in the subway and transit systems is often less than what you find in the soil or even in your own stomach.

From the first study.

My favorite fact then and now is actually the about half of the D.

N.

A.

That we sequenced matched no known species.

It's never been seen before.

A new species means that it has to be at least 20% divergent from anything that's been seen before.

I mean If it was 100 page book of the genetic code, at least 20 pages would be completely new and never been seen before.

But some but evolution is conservative.

So actually a lot of pieces of DNA that we have.

Our bacteria viruses get recycled and reused, There is subway swabs and covered over 11,000 new bacteria and viruses.

There was all this unknown life really under our fingertips.

But then other species we could see it looked like they were bacteria that were associated more with rats.

Or sometimes we actually see the rat DNA itself.

Actually you can see cucumber DNA.

We could see plants and animals, we could see more plant DNA closer to the parks for example.

So we could actually see this entire ecosystem of life really reflected in the surfaces of the subway.

We've also seen a lot of new CRISPR or raise.

These are basically the bacterial immune systems that are defending against other viruses and they also could serve as a new way to understand how do the CRISPR systems work?

Can use them for new actually therapies or drugs or even treatments CRISPR is even being used right now for gene therapies.

And so finding these new bacterial functions could potentially lead the way towards new medicines.

So for commuters riding subways around the world, you might not want to touch the polls, turnstiles and seats like you used to, but the microbes underneath our fingers serve a purpose.

I would actually think it's okay to grab the subway pole.

If anything, the ecosystem we discovered shows that is a very consistent core microbiome that humans probably have evolved with.

And essentially probably could use the exposure to that environment.

So instead of being afraid of the subway, you could even go in with reckless abandon and uh, and grab it with some confidence.