Even though bacteria in Lechuguilla Cave have been cut off from the surface for millions of years and were never exposed to antibiotics for medicine or agriculture, most of the 93 strains analyzed in a new study are resistant to several antibiotics. Bacteria found in the cave have ways of fighting off up to 21 kinds of antibiotics, researchers from the University of Akron in Ohio and McMaster University in Hamilton, Canada, report online April 11 in PLoS ONE.
Most can defuse antibiotic substances made by other microbes, but unlike aboveground bacteria have little resistance to human-made antibiotics such as ciprofloxacin.
At least one cave species has evolved a new mechanism for inactivating daptomycin, a drug based on a compound made by some bacteria, raising the possibility that natural populations of bacteria could pass on antibiotic resistance genes to bacteria that infect people.
