Antibacterial activity and mechanism of action of canthin-6-one against Staphylococcus aureus and its application on beef preservation

This work investigated the antibacterial activity and mechanism of canthin-6-one (CAN) on Staphylococcus aureus (S. aureus). CAN could inhibit the growth of S. aureus with minimum inhibitory concentration (MIC) of 16 μg/mL, exhibiting weak trends in resistance, good biosafety and acceptable stability. Furthermore, 5.30 log-units of S. aureus in beef soup were reduced after treated by 32 μg/mL of CAN at 37 oC for 3 days. The antibacterial mechanism indicated that CAN disrupted the bacterial biofilm and decreased the counts of living bacteria in it. Moreover, CAN could damage membrane accompanied with lipid peroxidation and lipid metabolism disorders. Amino acids metabolism disturbances were observed and energy system perturbations corresponded to the decreased activity of respiration enzyme. Importantly, the bacterial reproduction was disrupted by influencing folate and nucleotide metabolisms or directly damaging the function of DNA related targets. These findings confirmed the potential of CAN used in food preservation and provided a new insight into its antibacterial mechanism.