Antibacterial mechanisms of clove essential oil against Staphylococcus aureus and its application in pork

Clove essential oil (CEO) has been widely used in the processing of meat products due to its potent antibacterial activity and special aroma. However, studies on the antibacterial mechanism of CEO are still not detailed enough. The aims of this study were to investigate the antibacterial mechanisms of action of CEO against Staphylococcus aureus in detail and evaluate its efficacy in pork preservation. The Staphylococcus aureus cells treated with CEO were morphologically damaged and had significant leakage of intracellular components. At the metabolic level, CEO significantly inhibited the respiratory metabolism of Staphylococcus aureus by inhibiting the tricarboxylic acid cycle pathway and the total inhibition rate was found to be 31.23 %. Molecular biology experiments showed that CEO could interact with Staphylococcus aureus DNA molecules and affect the accessory gene regulator (Agr) system, which resulted in a significant decrease in the expression levels of Staphylococcus aureus virulence genes so that the expression of sea and hla decreased by 82.97 % and 77.27 %, respectively. Molecular docking results indicated that the interaction between eugenol, the main active ingredient in CEO, and the key phosphorylase Agr C in the Agr system may be one of the main reasons for the inhibition. The application results showed that CEO had a good antibacterial effect in pork for 7 days without affecting the texture of pork. The results obtained in this study provide a reference for an in-depth study of the detailed antibacterial mechanism of natural food antibacterial agents.