2014-07-08

Co.Exist

Can We Ever Get Our Antibiotics Working Again?

After years of overprescribing led to bacteria that can resist our strongest medicines, doctors and scientists are trying to plot a course back to a time when our drugs worked.

The discovery of penicillin was a major medical miracle of the last century. Infections that were once deadly could be cured by simple drugs. As germs grow increasingly resistant to antibiotics in this century, now a huge fear is that we are reverting to the past: In April, the World Health Organization itself warned we are quickly headed to a "post-antibiotic era," in which "common infections and minor injuries which have been treatable for decades can once again kill."

Calling the problem a "time bomb," UK Prime Minister David Cameron talked this month about giving more incentives to drug companies to develop new classes of antibiotics, which hasn’t occurred since 1987. (One reason is a Catch-22: It’s harder for companies to profit on a drug that may not work in a few more decades.)

The world is also finally starting to try and curb the overuse of antibiotics in both humans and livestock. In 2012, for example, the FDA banned the use of some human antibiotics in food producing animals, and recently the American Medical Association called on its members to support a full ban on all antibiotics in farm animals.

But what if there’s a better way forward than developing new drugs? What if we could "reverse evolution" and take germs to the state they were in the 1960s, when drug resistance wasn’t such a big problem?

That’s the idea of Miriam Barlow, a research scientist who studies the evolution of bacteria in her lab at the University of California, Merced. She is studying a gene often found in bacteria that cause urinary tract infections and pneumonia and helps them resist penicillin-type drugs.

Because of evolutionary pressures and tradeoffs, resistance to one antibiotic often makes bacteria more susceptible to other kinds of antibiotics, she’s learned. She figures that if doctors can use existing antibiotics in precisely the right order, they can slowly force a bacterial population to evolve backwards. In her mathematical models for the gene she’s studying, her team found a "60% to 70% probability of going back to go back to the original resistance gene."

"If we can reverse [this] evolution, then it’s a major step towards being able to use penicillin-related drugs more reliably," she says. This would be a very positive development, she says, because newer antibiotics tend to have more toxic side effects.

The idea isn’t completely new, and some hospitals—which are usually where the worst problems of antibiotic resistance develop—are already trying this idea of "antibiotic cycling," in which they take three or four antibiotics and try to rotate their use. Barlow says, however, so far the efforts have not been strategic enough.

"It’s a really a big deal. This is one of the places where medicine has actually been way ahead of the science," she says. "Doctors have been trying this, but they didn’t have any rational approach for cycling which antibiotics. They were hoping that just by not using it, antibiotic resistance would go away."

Her work, which she has submitted to a peer-reviewed journal but has not been published yet, shows that with this random approach, it might take a hundred years for resistance to go away. But by being more strategic and with a lot of coordination, she says hospitals could speed up evolution and remove resistance in a few years.

Doing this in a single hospital, let alone across the U.S. and the world, wouldn’t be easy. But the problem is becoming more urgent. Already in the U.S., about 23,000 people die of antibiotic resistant infections every year.

"Right now, it’s usually very young kids under 3 and people over 65," she says. "As it moves to people in their twenties and thirties, maybe it’ll get more attention. We’re really heading back to a situation, when maybe our great grandparents lived, where you get sick a lot and people just end up dying. That’s already happening to some extent, but I think it will continue to get worse and worse if we’re not making major efforts to prevent it."

[Image: Bacteria via Shutterstock]

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