Antibacterial mechanism of octyl gallate against methicillin-resistant staphylococcus aureus and its application in pork preservation: insights from multi-omics and computational simulation.

The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) in the food chain, particularly in pork, has become an urgent public health and food safety challenge. However, safe and effective food-grade preservatives capable of both eliminating MRSA and elucidating clear antibacterial mechanisms remain limited. Herein, the food-grade additive octyl gallate (OG) exhibited remarkable activity against MRSA, with a minimum inhibitory concentration (MIC) of only 20 μg/mL and completely eradicating MRSA at 40 μg/mL within 2 h, demonstrating potent efficacy comparable to vancomycin. Notably, OG significantly inhibited 72.7% of MRSA biofilm formation and eradicated 64.2% of mature biofilms at 1× MIC. Combined transcriptomic and proteomic analyses revealed that OG disrupted membrane transport, ribosomes, and amino acid metabolism. Moreover, OG inhibited biofilm formation by suppressing bacterial adhesion, while the activation of the Agr quorum-sensing system was likely involved in the eradication of mature biofilms. Complementary molecular docking and dynamics further suggested potential interactions between OG and dapB, ilvD and pdxS, providing structural support for its multi-target mode of action. In practical application, OG significantly inhibited MRSA growth on pork stored at 4 °C, with a 26.40% reduction at 2 × MIC. Moreover, OG effectively preserved meat quality by delaying pH elevation, lipid oxidation, and color deterioration, which collectively extended the shelf life from 6 to 8-10 d. Overall, these findings uncovered a novel antimicrobial mechanism of OG against MRSA and demonstrate its potential as a safe, effective food-grade preservative for controlling MRSA contamination and prolonging pork shelf life.