Protocatechualdehyde (PA) is a phenolic acid present in many plants and has many biological activities. Herein. the antagonistic effects and the action mechanism of PA against methicillin-resistant Staphylococcus aureus (MRSA) were studied. The results showed that PA had both significant antibacterial and anti-biofilm activities against MRSA. https://herbsdailyes.shop/product-category/medical-and-ambulatory-supplies-ambulatory-equipment/