Scientists Hit Antibiotic Pay Dirt Growing Finicky Bacteria In Lab
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Scientists have discovered a natural compound from bacteria that may prove to be a potent new antibiotic. This news comes at a time when many popular antibiotics are losing their effectiveness as germs develop resistance to them. This natural compound is especially intriguing because it appears that it might not lose its germ-killing potential. NPR's Richard Harris tells us how this discovery came about.
RICHARD HARRIS, BYLINE: Researchers at Northeastern University didn't set out to find antibiotics. Kim Lewis and his colleagues were actually figuring out how to grow bacteria that had never been grown in the lab before.
KIM LEWIS: The majority of bacteria on this planet are uncultured, meaning they do not grow on our Petri dishes. And when I'm talking about the majority, it is 99 percent.
HARRIS: So how do you grow bacteria that don't want to grow in the lab?
LEWIS: We don't grow them in the lab. That's how we do it.
HARRIS: Lewis and his colleagues developed a system that would allow them to explore this biologically-rich but secretive world. Basically, they built a vessel that would hold bacteria-rich soil between two membranes.
LEWIS: And then this contraption, which we call a diffusion chamber, it goes back into the soil from which we took the bacteria.
HARRIS: It turns out, once bacteria started growing and building tiny colonies in the contraption, those colonies could be transferred to the lab. At that point, they'd grow. And Lewis's lab was off to the races. Now, most of our antibiotics are natural products secreted by bacteria and fungi that live in the soil. So Lewis, with a company he co-founded called NovoBiotic Pharmaceuticals, started examining the natural compound secreted by his newly-isolated soil bacteria to look for new antibiotics. They've already found more than two dozen. And one of them, which they've named teixobactin, looked like a winner - deadly to several different kinds of disease-causing bacteria but not toxic to mice.
LEWIS: And behaved very nicely. It cured mice of skin and thigh and lung infections.
HARRIS: It cured serious staph infections, strep and tuberculosis. But the best part came when they ran another set of crucial tests.
LEWIS: The most intriguing thing about this compound is the apparent absence of resistance development.
HARRIS: It seems that disease-causing bacteria don't become immune to this antibiotic, and that's because the antibiotic latches onto parts of the bacteria that can't mutate, and mutations are how bacteria typically develop resistance to drugs. So Lewis is tentatively making a bold claim.
LEWIS: This for all practical purposes may be a largely resistance-free compound.
GERRY WRIGHT: That's pretty exciting news, I think, for the field.
HARRIS: Gerry Wright at McMaster University in Canada got a sneak-peek at the study, which is published in the latest issue of "Nature." Antibiotic resistance keeps infectious disease doctors up at night. For instance, there are some strains of tuberculosis that have developed resistance to all known antibiotics. Still, getting from discovery to drug isn't easy. Wright says there are economic and regulatory challenges in bringing a new antibiotic to market, which governments have been working to solve.
WRIGHT: We're moving in the right direction there, and so if we can kick-start the science at the same time then I think we'll have a route towards helping to solve the antibiotics crisis.
HARRIS: Scientists still need to test teixobactin in people, and there's no guarantee it will work as well in humans as it does in mice. But even if this particular product doesn't pan out, Lewis and his colleagues at Northeastern have plenty of other tough-to-grow bacteria that they can now study in the hunt for new antibiotics.
Richard Harris, NPR News.
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