Study suggests way to reverse bacterial resistance to antibiotics

Researchers at UC Merced have helped develop a new method to reverse bacterial resistance to antibiotics.

In a new study, published Wednesday in the peer-reviewed scientific journal PLOS ONE, researchers show how to reverse resistance in a drug environment and how doctors can apply this to a clinical setting.

The new work comes at a time when the rise of antibiotics-resistant bacteria is becoming a growing problem in the United States and in the world.

According to the U.S. Centers for Disease Control and Prevention, more than 2 million people in this country get infections that are resistant to antibiotics, and 23,000 people die as a result.

But resistance to antibiotics is a natural and unavoidable part of the evolution of bacteria.

In dealing with bacterial evolution, a doctor fighting infections in an intensive care unit may need to reduce, rotate or discontinue different antibiotics for them to continue being effective.

Miriam Barlow, a biology professor at UC Merced, said “antibiotic cycling,” in which different antibiotics are used on a rotating basis, has been tried in the past, but without much success. This new research, she said, brings to the table a theoretical and computational foundation, making it a more valid method.

Barlow explained that bacterial resistance to antibiotics has become more prevalent because pharmaceutical companies don’t produce as many antibiotics as they used to. This is dangerous, she said, because when bacteria become powerful enough that antibiotics no longer work, even small infections can become deadly.

Barlow worked with professors from American University and UC Berkeley. Together the researchers created bacteria in a lab, exposed the bacteria to 15 different antibiotics and measured their growth rates.

The researchers then computed how many mutations it would take to return the bacteria to its harmless state. The professors tested up to six drugs in rotation at a time, and made thousands of measurements of resistance to form plans for reversing the evolution of the bacteria.

“The goal is to push the enzyme back to its ancestral state,” Barlow said. “By changing from one antibiotic to another, you’re allowing (the bacteria) to evolve in a way that although there will be resistance to one thing, there will also be susceptibility to others.”

Mathematician Kristina Crona from American University in Washington, D.C., helped combine the lab work with mathematics and computer technology.

“Scientists now have lots and lots of data, but they need to make sense of it,” Crona said in a press release. “Mathematics helps one to draw interpretations, find patterns and give insight into medical applications.”

The next step for researchers is to conduct lab experiments to verify the work. Barlow said they plan on creating a complex environment in the lab, similar to that of a hospital.

Once they obtain results, researchers can reach out to hospitals and pharmacies to look at their treatment plans. The work, Barlow explained, does not have to go through clinical trials because they are working only with drugs that already exist.

“It just has to make sense to doctors so that they can responsibly prescribe it” to patients, she said.

“This work shows that there is still hope for antibiotics if we use them intelligently.”

This story was originally published May 8, 2015 at 7:13 PM with the headline "Study suggests way to reverse bacterial resistance to antibiotics."