'Noxious Weed' May Provide New Way to Fight Superbugs

Image: Brazilian pepper, aroeira, rose pepper, Christmasberry tree
Berries of the Brazilian Peppertreejantroyka / Getty Images

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By Maggie Fox

A noxious weed that plagues homeowners across Florida may hold the secret to a new way to fight some antibiotic-resistant superbugs, researchers reported Friday.

A compound made by the red berries of the Brazilian peppertree disarms methicillin-resistant Staphylococcus aureus (MRSA), the team at Emory University reports.

Schinus terebinthifolia Raddi is classified as a Category I pest plant by the Florida Exotic Pest Plant CouncilScientific Reports

What’s unusual is 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, who reported her team’s findings in the journal Scientific Reports.

Her lab broke it down and tested it on bacteria, human skin cells and in animals.

Related: WHO Labels Superbugs as a Fundamental Threat

It works it an unexpected way — as a so-called quorum quencher.

“It’s stopping communication among the bacteria,” Quave told NBC News.

“It kind of tricks them into believing they are alone. When they are alone, they behave differently than when they are in a group.”

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“This remedy, which been used for hundreds of years … works not by killing staph but by basically disarming it.”

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.

“They are used by staph to better invade the host and disseminate in the host,” Quave said.

Related: 'Nightmare Bacteria' Found in U.S.

The little red berries of the Brazilian peppertree produces a group of compounds that stops this.

“This remedy, which been used for hundreds of years … works not by killing staph but by basically disarming it,” Quave said.

“This could potentially open up new doors in the way that we treat staph infections in the future.”

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.

Related: Medieval Recipe Kills Germs

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.

Cassandra Quave of Emory UniversityAnn Borden

“Natural is not always safe. There are lots of things in the natural world that can harm you if you use them improperly .”

Related: Here's Why Superbugs Scare Doctors

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.

President Barack Obama ordered his administration to hurry up and do something about drug-resistant bacteria. It's not clear what the new Trump administration's policies will be.

Infections caused by antibiotic-resistant bacteria kill 23,000 people every year, make 2 million more sick and cost $35 billion in productivity lost to sick days, the CDC says.