CURWOOD: It’s Living on Earth, I’m Steve Curwood. In a minute, trees that travel, but first this note on emerging science from Don Lyman.

LYMAN: The Brazilian peppertree is a weedy, invasive species native to South America. Although considered a nuisance in Florida, where it grows in dense thickets and crowds out native plants, scientists at Emory University say traditional healers in the Amazon have treated wounds and skin infections with its bark and berries for hundreds of years.

Now, the Emory researchers have isolated a compound from the berries that appears to prevent skin lesions in mice infected with MRSA, methicillin-resistant Staphylococcus aureus, a bacterium that can cause serious infections, and is resistant to penicillin and cephalosporin antibiotics.

The scientists say that the compound doesn’t kill the bacteria, but represses a gene that allows them to communicate. This essentially disarms the MRSA bacteria and prevents them from excreting toxins that damage tissues.

Antibiotic-resistant infections are a widespread and growing problem that cause about two million illnesses and 23,000 deaths in the United States each year. The researchers say the Brazilian pepper tree extract could not only provide new ways to treat and prevent these infections, but do so without boosting the bacteria’s ability to resist our antibiotics. That’s this week’s note on emerging science. I’m Don Lyman.