In vitro and in vivo characterization of the antibacterial activity and membrane damage mechanism of quinic acid against Staphylococcus aureus

In this study, we investigated the antibacterial activity of quinic acid (QA) and elucidated its membrane action mechanism against Staphylococcus aureus. In vitro antibacterial assay showed that QA effectively inhibited the growth of test bacteria. In model food systems of cabbage suspension and barley soup, QA possessed a great antibacterial capacity. The membrane hyperpolarization and a decrease of membrane fluidity demonstrated a significant effect of QA on damaging the normal functions of cell membrane, which was further validated by the observation of the transmission electron microscope. The interaction of QA with Phe residues in the membrane protein was revealed by fluorescence quenching. Overall, the present study illustrates QA as a potent antibacterial agent and its inhibition action on S.aureus by damaging the cell membrane. Practical applicationsIn model food systems of cabbage suspension and barley soup, QA possessed a great antibacterial capacity to control the total counts of viable bacteria. This study provided the theoretical foundations for the application of QA in foods to prevent the growth of foodborne pathogens.