Brazilian peppertree packs power to knock out antibiotic-resistant bacteria

The red berries of the Brazilian peppertree – a weedy, invasive species common in Florida – contain an extract with the power to disarm dangerous antibiotic-resistant staph bacteria, scientists at Emory University have discovered.

The journal Scientific Reports published the finding, made in the lab of Cassandra Quave, an assistant professor in Emory’s Center for the Study of Human Health and in the School of Medicine’s Department of Dermatology. Dr. Quave is also a faculty member in the MMG and MSP programs.

“Traditional healers in the Amazon have used the Brazilian peppertree for hundreds of years to treat infections of the skin and soft tissues,” Quave says. “We pulled apart the chemical ingredients of the berries and systematically tested them against disease-causing bacteria to uncover a medicinal mechanism of this plant.”

The researchers showed that a refined, flavone-rich composition extracted from the berries inhibits formation of skin lesions in mice infected with methicillin-resistant Staphylococcus auereus (MRSA). The compound works not by killing the MRSA bacteria, but by repressing a gene that allows the bacteria cells to communicate with one another. Blocking that communication prevents the cells from taking collective action, a mechanism known as quorum quenching.

“It essentially disarms the MRSA bacteria, preventing it from excreting the toxins it uses as weapons to damage tissues,” Quave says. “The body’s normal immune system then stands a better chance of healing a wound.”

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