NPR : News

Why Scientists Are Trying Viruses To Beat Back Bacteria

Not all viruses are bad for us. Some of them might even help up us fight off bacterial infections someday.

Naturally occurring viruses called bacteriophages attack specific types of bacteria. So researchers at the University of Leicester decided to try and take advantage of phages' bacteria-destroying powers to treat infections with Clostridium difficile, a germ that that can cause severe diarrhea and inflammation of the gastrointestinal tract.

Over the last six years, microbiologist Martha Clokie has isolated hundreds of phages that can kill various strains of C. difficile. Now her lab has teamed up with the pharmaceutical company AmpliPhi to try and turn phages into a product, perhaps a pill, that could be used in humans.

There's no guarantee the approach will work, and so far it hasn't been put to a rigorous test in humans infected with C. difficile. Still, there are some good reasons to check it out.

C. difficile is difficult to treat with antibiotics and is resistant to many of them. Another problem is that the germ often strikes when people take antibiotics to treat other infections. The antibiotics kill good bacteria along with the bad, weakening the gut's defenses against C. diff.

Doctors are using fecal transplants and synthetic poop as possible solutions. But Clokie says that phages could be a useful alternative. "We're simply harnessing the natural enemy of the bacteria," she tells Shots.

Unlike bacteria, Clokie says, phages are very specific about what they attack—right down to the sub-species. In fact, a single phage wouldn't be able to take on all the strains of C. difficle. So Clokie is working to develop a cocktail of viruses that would be able to kill the most common strains.

While the bacteria can evolve and try to outsmart the viruses, the viruses can do the same, Clokie says. They've been involved in this arms race for thousands of years.

As long as they can come up with the right cocktail, there's a very good chance that this phage therapy could work, according to Tim Lu, an associate professor of bioengineering at MIT. "If you know what you want to kill, it's kind of like a silver bullet targeting that bacteria," he tells Shots.

And delivering the phages to a person's gut shouldn't be a challenge, Lu says.

Phages are already approved for use in meat and poultry production. Manufacturers sometimes spray food with phages that target listeria, a common food-borne bacterium.

But using phage therapy in humans is a bit more complicated. "Phages were discovered before antibiotics came around," Lu says. And they've been used in humans, he says. But the problem is, they have yet to be tested in well-controlled clinical trials.

There's also the question of intellectual property. Phages are naturally occurring, and therefore they're difficult to patent, which could discourage pharmaceutical companies.

Ultimately, Lu says, "The science is real." The stuff does work. But, he says, "It's a change in the way we think about treating infections, I think that's the biggest hurdle in a way."

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

NPR

'Game Of Thrones' Evolves On Women In Explosive Sixth Season

The sixth season of HBO's Game of Thrones showed a real evolution in the way the show portrays women and in the season finale, several female characters ascended to power. NPR's Kelly McEvers talks to Glen Weldon from NPR's Pop Culture Happy Hour and Greta Johnsen, host of the Nerdette podcast, about the show.
NPR

In Quest For Happier Chickens, Perdue Shifts How Birds Live And Die

Perdue Farms, one of the largest poultry companies in the country, says it will change its slaughter methods and also some of its poultry houses. Animal welfare groups are cheering.
WAMU 88.5

Jonathan Rauch On How American Politics Went Insane

Party insiders and backroom deals: One author on why we need to bring back old-time politics.

WAMU 88.5

Episode 5: Why 1986 Still Matters

In 1986, a federal official issued a warning: If Metro continued to expand rapidly, the system faced a future of stark choices over maintaining existing infrastructure. Metro chose expansion. We talk to a historian about that decision. We also hear from a former Metro general manager about the following years, and from an Arlington planner about measuring how riders are responding to SafeTrack.

Leave a Comment

Help keep the conversation civil. Please refer to our Terms of Use and Code of Conduct before posting your comments.