the average person has a ratio of human
to bacterial cells about one to one you
might think of yourself as human but I
prefer to think of you as extremely
outnumbered one human to approximately
39 trillion distinct bacterial organisms
however if you were to remove each and
every bacterium from your body all 39
trillion cells would only weigh about 37
grams but only about five hundredths of
a percent of your mass it seems
incredible then but such a tiny fraction
of your body could be so important not
only a bacterial key to physiological
processes like digestion and even human
emotions they call serious illnesses
which we have only learned to deal with
in the last century bacteria are more
complex than what was once believed what
scientists have found is that thinking
of bacteria in terms of individual
organisms just isn't practical and that
in fact that everything they do is the
result of inter bacterial communication
this opens up whole new worlds of
possibilities new ways to treat
bacterial infections and for this reason
today I'm here to talk to you about why
we can't kill the bad bacteria and why
maybe we won't have to this idea of
treating bacterial infections without
actually killing the bacteria goes
against about 90 years of antibiotics
era wisdom but now as antibiotic
resistant organisms become more and more
of a problem humans need to find ways of
asking better questions like how can we
treat bacterial infections without
antibiotics and in the process
potentially outsmart natural selection
but before I get into solving this
problem let's try to figure out how we
got here in the first place today
happens to be my birthday I'm turning 18
but without antibiotics it's possible I
wouldn't be or more likely that I'd be
here in a wheelchair last school year I
got Lyme disease after being bitten by a
tick or collecting data in the forest
for my biology class as it happened I
got a prescription for about ten days of
antibiotics without antibiotics I would
have been at risk for partial paralysis
and a whole host of other scary symptoms
more importantly if any of us had been
around in a time where antibiotics
weren't readily available chances are
some of us wouldn't be around today it
has been estimated that the life
expectancy of the average western person
would drop to around 50 without
antibiotics that means that many of you
in the audience would be on your last
legs or dead
antibiotics really are the magic
medicine that changed the world
they turned the once deadly infected cut
into the non-issue it is today and
prevented millions of people from dying
from illnesses like pneumonia
tuberculosis and scarlet fever however
as we know antibiotics are by no means a
perfect solution Alexander Fleming the
man responsible for the discovery of
penicillin was well aware of the risks
of misusing the drug in his Nobel Prize
acceptance speech he said that those who
did were morally responsible for the
death of the man who succumbs to
penicillin resistant organisms and he
was right humans have only themselves to
blame for what has happened since what
we have seen is a predictable succession
of new drugs being developed
followed by resistance being observed
within only a few years antibiotic
resistance has become a major problem
largely because of the way the drugs
have been used according to the Center
for Disease Control
one in three prescriptions of
antibiotics are unnecessary the
statistic points to a major flaw in the
way antibiotic
prescribes and possibly on the fact of
patient expectations when you seek
medical care think for a second about
what you expect when you go to the
doctor with a cold that just won't go
away do you expect antibiotics do you
even ask for them the fact is that 95%
of chest colds are viral antibiotics
aren't going to help you there and this
is where the problem really begins each
time antibiotics are taken the majority
of bacteria are killed leaving only
those with mutation allowing them to be
immune to the effects of the drug to
survive the fact that antibiotics are
prescribed way more than they should be
means that resistant strains of bacteria
are far more common but it isn't just
human use that is driving this epidemic
when antibiotics are used in mass in
factory farming not only are resistant
strains of bacteria produced but they
are transported among other things
through manure to agriculture the result
is that humans come in frequent contact
with resistant strains of bacteria
because of the food we eat global
factory farming now means that in the UK
for example forty five percent of all
antibiotics are given to animals the CDC
reports that one in five resistant
bacterial infections are caused by
animals or by food what this shows is
the complexity of the issue producing
new antibiotics requires large financial
investment and is becoming harder and
harder at the same time pharmaceutical
companies have no incentive to develop
new antibiotics because such a drug
would only be used as a last resort
meaning there's no money to be made even
if there was an incentive new
antibiotics are not a solution to the
problem when they only prolong the
inevitable a superbug which is immune to
all of our antibiotics the point
is that this is really serious we have a
problem which could potentially end
human life and our solution only worsens
the issue now when I originally decided
to do this talk my conclusion was
basically going to be and that's why
humanity could be well wiped out any
moment now
my opinion there was no good solution
for the same reason I don't think humans
can save themselves from global warming
we like the way we live and we don't
like to change but in my research I came
across a new field of study which does
away with the idea of killing bacteria
but instead tries to stop them from
communicating it turns out that bacteria
are more than millions of tiny organisms
working independently but that in actual
fact that everything they do including
to become pathogenic is through a
process called quorum sensing bacteria
work much the way an army does a lone
soldier out on the battlefield would be
extremely brave potentially suicidal if
he were to run out against an entire
army by himself instead as an army
prepares for battle each soldier is
likely heartened to look around and see
an uncountable number of other soldiers
also ready to run at the enemy like
soldiers bacteria do not work alone they
use quorum sensing to measure population
density to make sure that they don't
take on battles they don't have the
chance to win the way it works is that
each bacterium sends out a specific
chemical or autoinducer while also
interpreting the chemicals sent out by
bacteria all around them in this way
bacteria are able to tell whether there
are enough of them to perform mass
actions now what scientists at Princeton
discovered through animal research was
that by disrupting this process not only
could bacterial diseases treated but
natural selection can be evaded
instead of applying a selective pressure
to the population and leaving only
resistant genes in the gene pool
this concept means that bacteria have no
chance to become resistant this all
sounds fantastic but scientists are
working on are drugs that either prevent
the bacteria from creating or releasing
these autoinducers or prevent them from
interpreting them what this means is
that even if potentially harmful
bacteria were to enter your body
they'd have no chance to become a
disease because they wouldn't know that
they were enough for them to be an
infection the problem however is that
these concepts have never been fully
applied to human clinical trials while
some quorum sensing inhibition concepts
have as part of largely unrelated
research been tested the idea as a whole
has only really been shown to work in
animals at the same time the CDC reports
that in the US alone over two million
people are infected with resistant
bacterial infections per year and that
22,000 died it seems the superbugs of
science fiction are becoming a reality
what makes me angry is that instead of
pouring money into the solution really
making it the priority that it should be
not only our pharmaceutical companies
not doing this or even producing new
antibiotics they instead choose to focus
their efforts are marketing their
current drugs and in the process only
worsen the issue all of this being said
I would argue that if these concepts are
applied to human research this could end
up being the most significant medical
discovery since penicillin what has been
proposed is a solution to what many
including myself what was an unsolvable
problem thank you
[Applause]