Staphylococcus aureus (S. aureus) biofilms are of considerable interest in food safety due to the increase risk of the food contamination. This study aimed to explore the anti-biofilm mechanisms of cyclo (L-Phe-L-Pro) (cFP) against S. aureus with respect to its changes on extracellular polymeric substances (EPS) and gene expression. Results showed that cFP decreased the viability of S. aureus biofilm, and inhibited the synthesis of EPS (extracellular proteins, extracellular polysaccharides, and extracellular DNA). Real-time qPCR revealed that cFP could affect the expression of polysaccharide intercellular adhesion (PIA) synthesis-related genes (icaR, icaA, icaB icaC and icaD) and quorum sensing-related genes (agrA, agrB, agrC, agrD, geh, hla and spa). In addition, molecular docking speculated that cFP could bind to AgrC, and the binding region was most likely between loop1 and loop2. The histidine kinase domain of AgrC may also played a role in the binding process. Finally, the application of cFP on food contact surface showed that cFP could inhibit the biofilm of S. aureus. These findings not only prove the practicable antibacterial activity of cFP, but provide new approach to decrease the risk of S. aureus contamination on food contact surface.

由于食品污染风险的增加，金黄色葡萄球菌( S. aureus ) 生物膜在食品安全中具有相当大的意义。本研究旨在探讨环 (L-Phe-L-Pro) (cFP) 对金黄色葡萄球菌的抗生物膜机制及其对细胞外聚合物 (EPS) 和基因表达的变化。结果表明，cFP 降低了金黄色葡萄球菌生物膜的活力，并抑制了 EPS（细胞外蛋白、细胞外多糖和细胞外 DNA）的合成。Real-time qPCR 显示 cFP 可影响多糖细胞间粘附 (PIA) 合成相关基因 ( icaR , icaA , icaB icaC和icaD）和群体感应相关基因（agrA 、 agrB 、 agrC、agrD、geh 、 hla和spa）。此外，分子对接推测cFP可以与AgrC结合，结合区域最有可能在loop1和loop2之间。AgrC 的组氨酸激酶结构域也可能在结合过程中发挥作用。最后，cF​​P在食品接触表面的应用表明cFP可以抑制金黄色葡萄球菌的生物膜。这些发现不仅证明了cFP具有实用的抗菌活性，而且为降低食品接触表面金黄色葡萄球菌污染的风险提供了新的途径。