The Rise of Superbugs by Clark Zhang

Antibiotics were the wonder drugs of the 20th century.

Now, amazingly antibiotics are responsible

for extending the average human life about ten years.

But we are currently in the middle of a global crisis where

antibiotics are loosing their effectiveness

against infectious diseases.

The headlines, if you can see them, are very alarming.

Bacteria are rapidly becoming resistant

to all of the antibiotics that we currently use.

Now, in order to understand the nature of this problem,

you have to understand bacteria.

We live in a world filled with bacteria.

Bacteria are everywhere.

Everything that you look at,

everything you touch,

everything you put in your mouth,

everything you sit on

is covered with millions and millions of bacteria.

They're so small

that you can't see them without a microscope.

But they're there. And they are literally everywhere.

You can find them at the bottom of the deepest part of the ocean.

You can find them at the top of the tallest mountain.

You can even find them in the polar ice caps.

They can live in places where there is no sunlight,

no oxygen, no food.

They can grow in radioactive waste,

and in toxic chemicals,

and in boiling hot springs.

When bacteria find a place where they can survive,

they'll multiply fast to very high numbers.

Now, one of the places that bacteria like to call home

is the human body.

A recent survey by microbiologists

identified over ten thousand different microbes

that live on, or in the human body.

In fact, there are more bacterial cells in you

than there are human cells.

And there are more bacteria genes in you

than human genes.

So you can argue that each one of you

is actually more bacterium than you are human.

(Laughter)

So, now we have established that

I am talking to a room full of bacteria --

(Laughter)

-- I'm going to flatter the audience here a little bit

and tell you that bacteria are amazing organisms.

And one of the things that makes them so amazing

is their ability to share genes with each other.

Now, I need to describe this a little bit more.

Because this lies at the heart of how

bacteria become resistant to antibiotics.

And I don't have any slides,

so I'll have to describe it to you.

As you probably know:

Who you are lies in your genes.

So, for example, if you're tall or you have blue eyes

is because you have genes that make you tall

or that give you blue eyes.

And likewise bacteria that can live in Antarctica

have genes that make them resistant to the cold.

And bacteria that are not killed by penicillin

have genes that make them resistant to penicillin.

So where did these genes come from?

Well, you are familiar with humans,

who are born with a set of genes,

that they inherit from their parents.

And they keep the same genes until the day that they die.

So, for example, if you're born with brown eyes,

even if you wish that you have blue eyes,

your eyes will remain brown until the day that you die.

Because these were the genes that you born with.

But this is not true for bacteria,

who are in a habit of sharing genes with each other

in some pretty incredible ways.

And one of the ways

the bacteria will share genes with each other,

is through picking genes up from their surroundings.

And they usually do this after one of their neighbors has died.

So we're going to refer to this technique as the funeral grab.

OK, bacteria Number 1 dies

and releases it's genes into the surroundings,

and now bacteria Number 2 will pick up some of these genes

and pull them in.

So now bacteria Number 2 can do something

that previously only bacteria Number 1 could do.

So this is equivalent of you going to the funeral

of someone who had blue eyes,

taking a piece of their body out of the casket

and eating it.

And hey! You have blue eyes too.

But now imagine that instead of blue eyes,

you now are resistant to tetracycline.

Another way that bacteria have

to share genes is through viruses.

So, yes, bacteria get their version of the flu too.

And there are a lot of viruses that will infect bacteria.

So, we're going to call this technique: the viral pass.

A virus will infect bacteria Number 1

and pick up some of its genes,

and then inject these genes into bacteria Number 2.

Now bacteria Number 2 can do something

that previously only bacteria Number 1 could do.

So this is the equivalent of you catching the flu

from someone who has blue eyes.

And after catch the flu, your eyes turn blue too.

But, now imagine that instead of blue eyes,

you're now resistant to methacycline.

And the third way that bacteria share genes is through sex.

So, yes, bacteria have sex too.

And they're actually pretty promiscuous.

So, we're going to refer to this technique

as makin' whoopee. (Laughter)

So bacteria Number 1, the donor,

builds a bridge to bacteria Number 2, the recipient,

through which genes are passed

from the donor to the recipient -

much like *** activity you're familiar with.

But at the end of this *** activity,

bacteria Number 2 can now do something,

that previously only bacteria Number 1 could do before sex.

So this is the equivalent of having sex with the blue-eyed partner.

And after sex, you eyes turn blue too.

(Laughter)

But now imagine instead of blue eyes,

now you are resistant to vancomycin.

(Laughter)

So you see bacteria have lots of ways

to share genes among each other.

And with over ten thousand different types of bacteria

in the human body alone,

not to mention the millions of bacteria everywhere that you look,

this is a huge community

that's sharing antibiotic-resistant genes with each other.

So, now in order to understand antibiotic resistence,

you have to understand how antibiotics actually work.

So, in many ways bacteria are very different than humans.

And what this means is they have a lot of components

that can be target by specific chemicals.

So antibiotics are fantastic drugs.

Because they can kill bacterium without harming the human

by recognizing something very specific in the bacterium

and not the human.

They work like a key and a lock,

very specifically finding and binding their target

which leads to inactivation of the bacterium.

But bacteria have evolved a number

of different defensive maneuvers

to avoid being killed by antibiotics.

So we're going to talk about three ways

that bacteria can become resistant.

And the first way we are going to call the "up-chuck".

The antibiotic targets something specific

inside the bacterial cell.

But as soon as the antibiotic gets inside,

the bacterium barfs it right back out.

Preventing it from finding its target.

This is a technique that bacteria use

to be resistant to tetracycline.

Another way we're going to call the "stealth mode".

So the antibiotic recognizes something specifically again in the bacterial cell.

So the bacterium changes the target just enough,

so that the antibiotic no longer recognizes it.

The target is in stealth mode.

The antibiotic has no effect.

And the bacterium is resistant.

This is a technique that bacteria use

to be resistant to streptomycin.

And the third way we're going to call "the ballistic missile defense".

The bacteria makes a type of weapon

that goes out and finds the antibiotic

before the antibiotic can find its target.

The bacterium sends out waves of this missiles

that breakdown the antibiotic

and allow the bacterium to survive.

So this is a technique that bacteria actually use

to be resistant to penicillin.

So you can see that the bacteria have

lots of simple and effective ways

to avoid being killed by antibiotics,

that include things like: upchucks, stealth modes

and ballistic missiles.

And the genes for these antibiotic resistant mechanisms

are shared among the bacteria.

Through funeral grabs, viral passes, and makin' whoopee.

So remember the important atributes of bacteria:

they are small,

they multiply fast, and they share genes.

Your body is chock-full

of millions of good, innocent bacteria,

that cause you no harm,

they live in a peaceful gated community inside of you.

(Laughter)

But now let's imagine that

some bad bugs move into this neighborhood,

and start causing trouble, being obnoxious,

playing loud music, trashing the neighborhood.

You feel sick.

You go to the doctor.

You get some antibiotics, and you take them.

The antibiotics kill off most of the bad bugs

and a lot of good bugs as well.

So now you're feeling better,

so you stop taking the antibiotics before the doctor prescribed.

So what happens next?

Well, let's say that one of the good bacteria was already resistant.

So when half of the neighborhood dies off

from this antibiotic armageddon,

it multiplies fast to occupy all the empty houses.

As in any war, in order to win,

we need to develop new and more powerful weapons

to fight and defeat them.

And the time to invest in new antibiotic is now,

before we're completely out of weapons.

This needs to be a continuous, sustained effort.

One that really should be considered

a global health arms race.

With funding support,

new antibiotic can be developed continuously,

and released continuously into the market.

As you can now appreciate,

it is inevitable bacteria will eventually become resistant to the next antibiotic.

But by this time, the next antibiotic will be ready.

A sobering thought is that

a number of people in this room

are only here today,

because antibiotics saved your lives

at some point in the past.

We need to avoid returning to the pre-antibiotic era,

where common bacterial infections,

resulting from things like a cut, or a scratch,

or a struck throat,

could sometimes be a death sentence.

In this manner, with new antibiotics,

we can maintain the upper hand

against the rise of the superbugs.

Thank you.

(Applause)

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