Resistant bacteria found in ancient cave could hold key to new antibiotics

The key to finding new antibiotics may be located in a New Mexico cave, researchers from McMaster University and the University of Akron indicate.

Researchers from McMaster University and the University of Akron have found an antibiotic-resistant bacteria that could be good news for fighting superbugs. The bacteria was found in Lechuguilla Cave in New Mexico. Until recently, the researchers say, the caves were isolated from human contact. The fact that they have built up defenses against antibiotics could indicate the presence of previously unknown, naturally occurring antibiotics, the researchers explained in a release. Such naturally occurring antibiotics could be used by doctors to treat infections they said.

The bacteria are not dangerous to humans, the scientists said, and are not capable of causing human disease. They have never been exposed to human sources of antibiotics, but researchers found that almost all of the bacteria were resistant to at least one antibiotic; some were found to be resistant to as many as 14 antibiotics—in total, resistance was found to almost every antibiotic currently used in medicine today.

"Our study shows that antibiotic resistance is hard-wired into bacteria. It could be billions of years old, but we have only been trying to understand it for the last 70 years," said McMaster’s Gerry Wright, scientific director of the Michael G. DeGroote Institutes for Infectious Disease Research, in a release. "This has important clinical implications. It suggests that there are far more antibiotics in the environment that could be found and used to treat currently untreatable infections."

Concern over antibiotic resistance has been an ongoing issue in medicine.

"In extreme cases these organisms are resistant to seven or more drugs and are untreatable using traditional treatment, and doctors must resort to surgery to remove infected tissue," said Wright. "The actual source of much of this resistance is harmless bacteria that live in the environment."

Additionally, the use of antibiotics in agriculture has made it difficult for scientists to study the resistance question in bacteria living in our environment, as it is hard to find a location that has not been affected by the use of antibiotics in some way. So, the Lechuguilla Cave environment, discovered in 1986 and since having its access limited, has been the perfect environment, scientists said, to study the pre-existing reservoir of antibiotic resistance in nature.

The researchers also identified resistance in bacteria related to the bacterium that causes anthrax. This resistance has yet to emerge in the clinic.

"We can say to doctors, 'While this isn't a problem right now, it could be in the future, so you need be aware of this pre-existing resistance and be prepared if it emerges in the clinic, or you are going to have a problem,'" said Hazel Barton, professor of biology at the University of Akron.

The research article, “Antibiotic Resistance Is Prevalent in an Isolated Cave Microbiome,” is available online at the PLoS ONE website.

Image: Wikimedia Commons: Photo by Dave Bunnell

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