Lysine Inhibits Hemolytic Activity of Staphylococcus aureus and Its Application in Food Model Contaminated with Staphylococcus aureus

HIGHLIGHTS: What are the main findings? Lysine inhibits hemolytic activity of S. aureus; Lysine inhibits the expression of toxin Hla of S. aureus; Lysine inhibits Hla oligomerization; Lysine attenuates S. aureus supernatant damage in mice and Caco-2 cells; Lysine inhibits the expression of Hla of S. aureus in a food model and had good biocompatibility. What is the implication of the main finding? Lysine has the potential to be used as an anti- S. aureus preparation in the food industry. ABSTRACT: Alpha-hemolysin (Hla) is one of the important exotoxins of Staphylococcus aureus (S. aureus) and can be used as a target to reduce the virulence of S. aureus. This study explored the inhibitory effect of Lysine (Lys) on Hla and its application in food safety. Lys significantly inhibited the expression of Hla at sub-inhibitory concentrations and directly interacted with Hla to interfere with its oligomerization and thus significantly inhibited its hemolytic activity. Notably, Lys attenuated S. aureus damage to mouse small intestine and Caco-2 cells and delayed mouse mortality. In the food model, Lys inhibited the expression of Hla of S. aureus and had no significant effect on the sensory score. Moreover, Lys had no obvious damage effect on the main organs of mice, which indicated that Lys has good biocompatibility and has the potential to be used in the food industry as an anti-S. aureus preparation.