Hundreds of bacteria isolated from soil samples are able to live exclusively on antibiotics as a food source, according to a report published today (April 3) in Science.

The researchers, led by George Church of Harvard Medical School, isolated bacteria from 11 distinct soil types. They showed that these bacteria could subsist in culture dishes exclusively on, in some cases, 13-17 of 18 classes of antibiotics, including penicillin and ciprofloxacin.

Church told The Scientist his group was initially surprised that they found bacteria that were not only resistant to common antibiotics but could metabolize them as well. Bacteria are commonly resistant to mild toxins in plant leaves and roots, whereas the sample bacteria were in soils where there should be no antibiotics present. "And there's plenty of other sources of food" normally, Church said. "So you might imagine there would be no need to develop this sort of ability."

"This study really shows us that antibiotics are not special," Gerry Wright, biochemist at McMaster University in Ontario, who was not involved in the study, told The Scientist. "We've known that antibiotic resistance is a big problem and have been searching for the source of their resistance. Clearly there are organisms that can have antibiotics for breakfast," which will help us understand how some bacteria develop resistance.

The new findings may help researchers understand the bacterial mechanisms of resistance but may have other practical applications as well. "I get excited by the findings because now maybe we can use these organisms to remove antibiotic contamination in the environment," Stuart Levy, microbiologist at Tufts University, who was also not involved in the study, told The Scientist. Having an identified group of bacteria that can break down and digest antibiotics could be used in water treatment plants to remove excess antibiotics leeched into runoff by farms and other human activity, he added.

If nothing else, this study will help remind us that resistance is a common thing, Wright added. "Antibiotics are hundreds of millions of years old," he said. "The idea that resistance hasn't co-evolved is insane, of course it has."