Foodborne Pathog Dis 2019 Apr 17. Epub 2019 Apr 17.
4 Department of Food Science, Fu Jen Catholic University, New Taipei City, Taiwan.
seeds contain many bioactive compounds commonly used in traditional Chinese medicine. In this study, the antibacterial activity and possible mechanism of seed ethanol extract (PCEE) against foodborne pathogens were investigated. Both methicillin-resistant (MRSA) and had similar minimum inhibitory concentrations and minimum bactericidal concentrations of PCEE at 50 and 100 μg/mL, respectively. Furthermore, elevated OD, protein concentration, and electric conductivity indicated irreversible damage to the cytoplasmic membranes of PCEE-treated cells. Indeed, the treated cells displayed disrupted membranes, incomplete and deformed shapes, and rupture as visualized by scanning electron microscopy. Multidrug-resistance efflux pump gene expression was also analyzed by quantitative reverse transcription PCR. Although the , , and genes of and the gene of MRSA were upregulated, there was no significant difference that indicated an attempt by the efflux pumps to discharge PCEE. MRSA expression and expression were significantly downregulated ( < 0.05). A possible mechanism for PCEE may be to cause an energy depletion, either by inhibiting adenosine triphosphate binding or by disturbing the proton gradient, resulting in membrane damage.