Transcript

NARRATOR

Scientists are now trying to understand exactly how superbugs have gained resistance, and ultimately how we can defeat them. Here at Harvard University scientists are investigating why some of our antibiotics are failing. It's an experiment that happens in Professor Roy Kishony's lab. Here they are deliberately trying to create superbugs.

ROY KISHONY

So this is a new device that we have developed. We call it the "morbidostat."

NARRATOR

Using the morbidostat they are going to produce a highly-resistant version of a harmless strain of a bacteria we all have in our gut, E. coli.

ROY KISHONY

In the beginning you have bacteria just going happily in the tube. They have enough food, so they're going fast.

NARRATOR

They start by trying to kill the E. coli by dripping in a low concentration of antibiotic. But as the millions of bacteria have been multiplying in the tubes, some, by chance, will have developed mutations that allow them to be resistant to the antibiotic.

ROY KISHONY

This mutant would start replicating faster than everyone else. Ultimately it would take over on the whole population.

NARRATOR

So now they try to kill this new mutant strain. They up the strength of the antibiotic. Again, most of them die. But a new mutation appears that can survive the even stronger antibiotic.

ROY KISHONY

And then see another step. Now we can go in even higher drug concentrations. So we keep iterating this process over and over and over.

NARRATOR

This experiment shows that bacteria become resistant by being exposed to low levels of the very thing we use to protect us – antibiotics. Now the team have created a new experiment to find out exactly what is happening in these mutant bacteria to allow them to be resistant. It starts with what is, in effect, a giant Petri dish.

ROY KISHONY

We're setting an experiment, really, for the first time in which we're going to let bacteria swim against an ever-increasing concentration of an antibiotic and see what happens.

NARRATOR

The jelly contains food for the bacteria to grow. But each slab is infused with an increasing concentration of antibiotic, which should act as a barrier, killing the bacteria.

ROY KISHONY

The first slab is no drug. Then about the amount that's needed to kill the bacteria. Then 10 times more, 100 times more, and 1000 times more.

NARRATOR

The experiment begins with a tiny drop of E. coli.

ROY KISHONY

They're certainly going to spread when there is no drug. But we want to see, can they actually go to the place where there is an antibiotic?