Air Date: Week of November 9, 2001

Living on Earth's Cynthia Graber reports on a new antibiotic found in sweat.

Transcript

ROSS: Just ahead: from Asian longhorn beetles to zebra mussels, a primer on nature's unwelcome guests. First, this Environmental Health Note from Cynthia Graber.

GRABER: Sweat is made up mostly of water, but it also contains trace amounts of compounds such as sodium, chloride, and ammonia. Now, it turns out that what's in sweat can help the body fight off bacterial infection.

German scientists discovered and separated out a protein in human sweat called dermacidin. They tested it against four different types of bacteria and found that the protein killed them all, including E. coli. The discovery of this anti-bacterial compound in sweat leads researchers to believe that sweat is part of the body's first line of defense against potential pathogens. It helps protect us even before more potent antibiotics in our skin jump into action to fend off infection from a cut or a wound. The bacterial fighting compound in sweat is unique, the researchers say.

Other anti-bacterial compounds in skin have a positive charge that allows them to kill microbes by disrupting their membranes. But the sweat compound dermacidin is negatively charged. Scientists aren't yet sure exactly how it kills. But if this new sweat compound works against bacteria that are now resistant to common antibiotics, it could offer a new tool for health care providers. That's this week's Health Note. I'm Cynthia Graber.

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ROSS: And you're listening to Living On Earth.