DNA that makes germs resistant against medicines may increasingly be polluting water, from rivers all the way to the faucet. Scientists caution these contaminants, if not cleansed, could exacerbate the growing problem of drug resistance among potentially harmful microbes. The genes join a long list of contaminants being found in water, posing a challenge for devising an effective means of treatment.

Currently the World Health Organization reports that drug-resistant germs infect more than two million people in the U.S. every year and that 14,000 die as a result. The rise of drug resistance among germs is tied to the widespread use of pharmaceuticals in humans and animals. Up to 95 percent of antibiotics are excreted unaltered, seeping into the environment and possibly encouraging antibiotic resistance there.