The red berries of the Brazilian peppertree make a compound that is able to disarm methicillin-resistant Staphylococcus aureus (MRSA), the team at Emory University reports.
What the researchers found unusual was that the berries don’t kill the bacteria, but simply stop them from doing harm, says Cassandra Quave, who studies ethnobotany and dermatology at Emory University in Atlanta.
“Traditional healers in the Amazon have used the Brazilian peppertree for hundreds of years to treat infections of the skin and soft tissues,” said Quave. Her team broke it down and tested it on bacteria, human skin cells and in animals.
It works unexpectedly as a so-called “quorum quencher”. It stops communication among the bacteria by tricking them into believing that they are alone, basically disarming them. When they are alone, they behave differently than when they are in a group, Quave said. They are used by staph to better invade the host and disseminate in the host.
MRSA bacteria can live harmlessly in the body, and the Centers for Disease Control and Prevention estimates that 2 percent of all healthy people just carry it in or on their bodies. But when they cause an infection, they do all sorts of nasty things — releasing toxins, blasting open red blood cells and tearing apart skin cells.
The little red berries of the Brazilian peppertree produces a group of compounds that stops this.”This could potentially open up new doors in the way that we treat staph infections in the future,”Quave said.
It’s the second natural quorum quencher that Quave’s team has found. In 2015, they reported that the leaves of the European chestnut tree produce a different group of compounds that similarly disarm staph bacteria.
The Brazilian peppertree is often also called the Florida holly or broad leaf peppertree. Its scientific name is Schinus terebinthifolia and it’s spread from its native South America to Florida, Alabama, Georgia, Texas and California.
“This is a noxious weed that is really hated in Florida,” Quave said. She finds it ironic that a weed that flourishes so well and is so hated that homeowners deploy Roundup and weed-whackers to kill it could have lifesaving properties.
Years of testing remain before the compound in the berries could be tested as treatments.
“I don’t want people to go out and try putting random berries on their skin,” Quave said.
“Natural is not always safe. There are lots of things in the natural world that can harm you if you use them improperly.”
Nature is a rich source of antibiotics and other drugs. Penicillin, the original antibiotic, is derived from mold. Researchers are looking for new drugs in dirt, tropical plants and the sea.
Infections caused by antibiotic-resistant bacteria kill 23,000 people every year, make 2 million more sick and cost US$35 billion in productivity lost to sick days, the US Centers for Disease Control and Prevention (CDC) says.