Researchers studying antibiotic use in Chinese swine have not only detected antibiotics in pig manure, but antibiotic resistant bacteria as well.

The findings appeared this week in the Proceedings of the National Academy of Science. One way the antibiotic-resistant microbes can enter the food supply is through water -- by way of runoff from the farm. Researchers say as a result, this a global issue, not just a local one.

In 2011, the Food and Drug Administration put the responsibility on pharmaceutical companies to voluntarily reduce sales of antibiotics to farmers. Last year, however, sales of penicillins and tetracyclines for animal use doubled from previous years.

Read More:

• Pig Manure Reveals More Reason To Worry About Antibiotics (NPR)
• Global Health Threat Seen in Overuse of Antibiotics on Chinese Pig Farms (New York Times)
• Animal Antibiotic Use Continues Upwards, USDA Keeps Blinders On (Huffington Post)