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this is a subway pole
a turnstile
a seat
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and this is what's underneath
we did see some geothermal filler
species which can survive on rocks and
hot environments we've also seen
staphylococcus epidermis the most common
species was cute bacner 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 out and
swabbed 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 a 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 theirs so
what do cities actually look like
underneath the microscope
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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
is geobacillus thermoleovorans which is
this really hearty microbe that can
survive on rocks and soil and even be
desiccated or dried out and you know
really takes a lick in and keeps on
ticking and goes on fine like i think
new yorkers you can see that you know
these really hardy microbes have evolved
for the harsh surfaces of the cities
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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 you
know 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 could sometimes pick up more in
naples than in other cities so that was
kind of interesting to see
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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 city 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 serve
not only as a gathering for sports and
human endeavors but also gives this
interesting you know addition like a
probiotic to a city essentially in a way
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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 is not
entirely clear so there's a chance that
you know 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 in their
people tokyo also had a range of new
phages or these viruses that attack
bacteria that we didn't see anywhere
else in the world including some phages
that are specific for c acne or a very
common skin microbe so you know 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
well 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
ninety seven percent of every swab that
we take so on the one hand there's this
core set of microbes that includes
things like cutaback or acne or
geothermophilus 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
are 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 extreme files on the
subway in particular some that can
survive in say the cooling waters of
nuclear power plants like dinococcus
radiodurans 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 surfaces
enrich foreign 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 to
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
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with subways teeming with bacteria
should commuters start to worry about
the microbes they'll 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 a disease we've
seen no evidence of a wealth of harmful
pathogens or really even that many
opportunistic pathogens in the city
centers or transit systems but rather
we've actually seen it seem to be a
relatively safe environment and even if
we look at things like antibiotic
resistance or these antimicrobial
resistance genes what you'll find in the
subway and transit systems is often less
than what you'd find in the soil or even
in your own stomach from the first study
my favorite fact then and now is
actually that about half of the dna that
we sequenced matched no known species it
never been seen before a new species
means that it has to be at least 20
divergent from anything that's been seen
before meaning 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 or bacteria viruses
get recycled and reuse
their subway swabs uncovered over 11 000
new bacteria and viruses
there was all this unknown life really
under our fingertips but then other
species we could see look like they were
bacteria that were associated more with
rats or sometimes we'd actually see the
rat dna itself actually you could 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 arrays 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 poles turned styles 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 it 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 or at
least i do at this point