New Ways to Kill Superbugs

Microbiologists are on the search for drugs to kill bacteria and after many experiments a super drug has been developed to do what antibiotics cannot.

 

TRANSCRIPT

Microbiologists are on the search for drugs to kill bacteria, and after many experiments, a super drug has been developed to do what antibiotics cannot.

Here's the story.

These are the bad bugs.

Actually, all of the bugs are in here.

Okay.

So we've got, you know, relatively bad bugs, and then we've got the really bad bugs.

And microbiologist Rebecca McDonald is searching for a drug that kills all of them.

So you can't go past the yellow and black line without wearing personal protective equipment.

These are bacteria that are growing, and they've got replicates.

Here is one drug candidate.

Here is another drug candidate, and if it's orange, it means that the bacteria are growing and respiring happily, and if it's blue, they've been killed.

Killing bad bugs is a goal for McDonald and the other researchers at Vast Therapeutics in Research Triangle Park, and after thousands of experiments, they believe they have found a super drug to kill superbugs.

We've killed almost 100 different bugs and superbugs, pathogens, bacteria on our way to, you know, rolling this out and to helping combat those things that antibiotics cannot do right now.

The key ingredient is a simple molecule, nitric oxide.

Your body already makes and uses this chemical compound as part of the natural immune system.

Nitric oxide has been made by your body for forever, so it makes lots of it per day.

It just doesn't put it in those places which might be the area of need.

So, if you have an infection in your lungs, say you're a cystic-fibrosis patient, and you've got mucus buildup.

You got biofilm.

You know, it's a really nasty environment.

Then you have bacteria colonizing on that.

Now you've got to get in there and penetrate through that layer of mucus or biofilm and get to the infection and actually do your job.

Nitric oxide can do that.

Trouble is, nitric oxide is a gas.

Scientists have found a way to dissolve the gas into a solution.

Then large amounts of nitric oxide are delivered into the body to fight infections.

Because where your delivering it is where it will end up acting and do so in a manner that does not negatively impact healthy cells and tissues.

It turns nitric oxide into a kind of natural smart bomb, attacking and then destroying bacterial cells in multiple ways.

This is an atomic-force-microscope image of a bacteria or a few bacteria before NO exposure and then after NO exposure.

What you'll see is that they don't look like that anymore.

You have essentially broken apart their exterior membrane.

Using nitric oxide as medicine isn't new.

Because it's naturally in the body, there's less chance of the body rejecting it as well as negative side effects.

Sometimes, the simplest explanation, the simplest idea, is the best idea.

You don't need to overcomplicate it.

But the challenge has been how best to deliver large amounts of nitric oxide into the body.

The discovery of how to put the gas into a solution is the first step.

The beauty of what we've got here is that we can link it to a solid molecule, that backbone, and deliver it that way, and then the gas releases over time, and so that's kind of gotten over that hurdle.

So our different drug candidates have a different carrier molecule.

They have different profiles, different solubilities.

So for different indications, one molecule might be better than another, and we're also just kind of playing with which molecules... Until you try it, you don't know.

So the particles that are being generated by this device are in the size of 1 micron to 10 microns, and to give you an idea of what that size is, a human hair is typically, say, 40 to 100 microns in diameter, so the particles this is generating are really quite small.

And I'm assuming that's important.

You need that small.

That's critical because we want these particles to go in and treat the disease inside the lungs, and so to get into the lungs, to get that deep penetration, we need the particles to be in the range of 10 to 1 micron.

So, you need a small particle, you need the right mass, and if you can control those two factors and you have the right velocity of the person breathing, a typical breathing pattern, then you can get good lung penetration, and we can get the medicine into the lungs to treat the infection.

Other methods to deliver the drug will be tried later.

These are two plates of Pseudomonas aeruginosa growing, and on the left is a plate that's about 1 day old, but after a time, they start producing this yellow pigment, which is called pyocyanin.

For now, McDonald's battle against superbugs continues, but she believes she has a powerful weapon.

We want to find out which bacterial pathogens do our different drug candidates... What are they effective against?

Is it broad range?

Is it a narrow spectrum?

You know, where are we?

So I went in, and I tested, you know, my favorite pathogen first, for example.

I'm like, 'Whoa! It kills it, you know, really well, so that's great,' and then, you know, next week, I'll go in, and I'll try another pathogen, and it killed it again, so that was fun, and that kind of went on and on to the point that we thought, 'We really got something here.'