A novel anti-virulence approach using punicalagin to combat methicillin-resistant Staphylococcus aureus infections

Methicillin-resistant Staphylococcus aureus (MRSA) is widespread in nature. Farm animals, such as pigs, cattle and poultry, are frequently colonized with MRSA, posing a severe threat to human health via their zoonotic transmission to humans by direct animal contact, environmental contamination, or livestock products. In this study, we identified a natural product, punicalagin (PA), that possesses potent antimicrobial activities by target screening of a key virulence factor crucial to bacterial attachment. Strong synergism between PA and an existing antibiotic led to a 99% reduction in bacterial load in major murine organs and completely protected mice infected by MRSA. Our findings demonstrate that as a natural product with a highly desired safety and bioavailability profile, PA presents a promising alternative to antimicrobial for its potent prophylactic and curative effects and can play an important role in mitigating antibiotic drug resistance.