The bacteria coat the walls of the Lechuguilla cave system on rock faces some 1,600 feet (487 meters) below Earth’s surface. Until recently, the microscopic life-forms had encountered neither humans nor modern antibiotics..
That’s because a thick dome of rock isolated the cave between four and seven million years ago. Any water that trickles through takes roughly ten thousand years to reach the cave’s depths—which means the subterranean life has existed entirely in the absence of modern medicine.
While not infectious to humans, the cave bacteria can resist multiple classes of antibiotics, including new synthetic drugs. The discovery serves as an intriguing lead in the quest to understand how drug-resistant diseases emerge.
“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,” said study leader Gerry Wright, a chemical biologist at McMaster University in Ontario.