Lone Bacteria Are More Likely to Become Drug Resistant Than Big Colonies

This finding could help design ways to prevent antibiotic resistance

Photo: David Spears FRPS FRMS/Corbis

There's a reason doctors and scientists are concerned about antibiotic resistance: 23,000 people die each year after picking up an infection of antibiotic-resistant bacteria, as science reporter Maryn McKenna recently pointed out. But researchers are still learning exactly how this resistance is acquired, and one study, which just came out in Nature Communications, found that bacteria colonized in relative isolation—"lonely bacteria"—are more likely to develop resistance to an antibiotic than those that grow in a large colony.

Specifically, the researchers exposed E. coli grown in both large and small colonies to Rifampicin, a drug used to treat tuberculosis. They measured the rate of mutation in those colonies. "We discovered that the rate at which E. coli mutates depends upon how many ‘friends’ it has around," the researchers said in a statement. "It seems that more lonely organisms are more likely to mutate.”

Mutations are how bacteria develop novel ways to bypass the deadly effects of drugs, and more frequent mutations create more chances to develop resistance. Researchers know the mechanism that makes bacteria mutate has something to do with signaling molecules, which communicate messages—such as whether or not to mutate—to other bacteria. If researchers could figure out a way to hack that system, they might be able prevent those signaling molecules' message from getting through, or from even being produced in the first place. 

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