April 12, 2012
Ancient Cave Bacteria Could Produce Better Drugs
Caves in New Mexico offer their visitors breath-taking views, lessons about Earth´s history, and plenty of jealousy-inducing photographs. But now team of microbiologists who recently visited the Lechuguilla cave systems found an even better souvenir to take home: Ancient bacteria with the power to fight off modern antibiotic drugs.
1,600 feet below the surface of the Earth, these bacteria lined the walls of the Lechuguilla cave, yet to be touched or discovered by humans or their drugs.
These bacteria, while resistant to antibiotics, aren´t infectious to humans. Their benefit to us, however, will be in their study. As these bacteria are able to resist new synthetic drugs, scientists will be able to study how bacteria withstand such medications, thereby creating better, more potent drugs.
Speaking with National Geographic reporter Dave Mosher, study leader and chemical biologist at McMaster University in Ontario said, “Clinical microbiologists have been perplexed for the longest time. When you bring a new antibiotic into the hospital, resistance inevitably appears shortly thereafter, within months to years.”
“It´s still a big question: Where is this coming from?” Wright said. “Almost no one thought to look at other bacteria, the ones that don´t necessarily cause disease.”
The US National Park Service has severely limited access to this pristine and untouched site, but has agreed to let geomicrobiologist Hazel Barton of Northern Kentucky University and her team sample the microbial life within.
Wright says the area is so pristine you can still see the tracks of everyone who has ever entered the cave.
Scraping off samples of thick mats of bacteria called biofilm from the cave walls, Barton then delivered her samples to Wright´s lab. There, his team spent three years analyzing the bacteria, looking for antibiotic resistance.
Disease-causing bacteria have often become resistant to antibiotics, usually quite quickly. These bacteria, called superbugs, can block, immobilize and even destroy natural and synthetic antibiotics. Such superbugs are usually found in hospitals where antibiotics are used frequently. These antibiotic-rich environments force the bacteria to react and adapt rapidly.
This isn´t Wright´s first time to look for ancient bacteria in untouched locales. Previously, Wright had found bacteria in ancient soils and permafrost, according to Julian Davies of the University of British Columbia. Davies was not involved in the study.
As Wright was able to grow 500 different kinds of bacteria from the cave walls, though only 93 kinds grew in a medium that allowed for testing of antibiotic resistance. Of these 93, 70 were able to resist 3 out of 4 different antibiotics.
“This tells us antibiotic resistance genes are very old, but what it doesn´t tell us is how they find their way into the hospital,” Davies said.
“I honestly didn´t expect to see the sheer diversity of genes fighting all of these different antimicrobial compounds,” said Wright.
Davies questions whether or not the bacteria were able to resist the antibiotics because they were grown in a lab or if they are naturally able to resist since they are so old.
As further testing is being conducted to determine any natural antibiotics in the cave, Wright says clinicians and pharmaceutical companies should be alert, should new developments arise.
image Caption: A researcher looking at gypsum flowers in 'Lebarge Borehole.' Credit: (c) Max Wisshak/speleo-foto.de