Author: Bethany Brookshire / Source: Science News for Students
Bacteria have a lot of ways to avoid the drugs people use to kill them. Some pump the drugs away. Others shield their vulnerable parts with protective coatings.
Some bacteria even chew up drugs. And if they’re chewing, why not also eat them? A new study shows how some microbes do just that: They turn the drugs meant to kill them into a bacterial buffet.Scientists might one day harness these findings to help rid the environment of polluting drugs.
Some of the first antibiotics — chemicals used to kill bacteria — were found in organisms living in soil. Bacteria, mold and other microbes constantly duke it out for space, food and other resources. Some have evolved chemicals to kill each other. People simply took those molecules and adapted them for medicine and other uses.
But in this kill-or-be-killed world, one bacterium’s weapon can trigger another’s new defense. And some bacteria living in the soil indeed have learned not only to break down antibiotics, but also to eat them.
Such bugs can use parts of the germ-killing drug as fuel, explains Daria Van Tyne at Harvard University in Cambridge, Mass. As a microbiologist she studies microbes.
All of this “makes sense,” Van Tyne says, “given that a lot of antibiotics come from the soil.” Until now, she points out, scientists did not know “exactly how the eating worked.”
To catch a drug eater
Gautam Dantas is a microbiologist at Washington University in St.
Louis, Mo. He and his colleagues set out to discover how bacteria could safely nosh on antibiotics. First, they had to find some germs that knew the trick. To do that, they needed dirt. “My father-in-law and mother-in-law live in Minnesota. They sent us some soil,” he says. “We [also] got some in Pennsylvania and went hiking in Massachusetts.”The scientists set up their soil samples in petri dishes — shallow dishes used to grow bacteria. Then they gave the soil microbes nothing to eat but antibiotics, such as penicillin. Afterward, they waited to see if any bacteria grew. Some did. The researchers then separated these bugs out, gave them more penicillin and let them grow some more.
“It was a tedious process,” Dantas says.
Though some bacteria can grow on antibiotics, they don’t much like it. “It’s not their preferred food,” he says. Bacteria usually feed on sugars or amino acids (the building blocks of proteins). When fed only antibiotics, the microbes grow at only one-half to one-third the rate they would when fed their usual diet.
After working with many, many petri dishes of germs, Dantas and his group were left with four types of bacteria that could survive dining on antibiotics. They now looked at the genes — cellular instructions — within these bacteria. They also looked at what chemicals these microbes produced. The scientists were hunting for a shared set of instructions that…
The post Nom, nom! These bacteria eat antibiotics for lunch appeared first on FeedBox.