Antibacterial activity and mechanism of the sesquiterpene δ-cadinene against Listeria monocytogenes

Abstract

Listeria monocytogenes is a food-borne pathogen that seriously threatens human health. We analyzed the antibacterial activity and mechanism of δ-cadinene against L. monocytogenes. The effect of δ-cadinene on L. monocytogenes gene expression was investigated using RNA sequencing. δ-Cadinene inhibited L. monocytogenes growth at a minimum inhibitory concentration of 5 μL/mL and a minimum bactericidal concentration of 10 μL/mL. In addition, δ-cadinene suppressed biofilm formation, altered cell morphology, and damaged the cell membrane of L. monocytogenes, enhancing membrane permeability and affecting the membrane potential. Of note, "plasma membrane" and "membrane" were the most significantly enriched Gene Ontology terms. Sixteen differentially expressed genes were strongly correlated with biofilm formation, protein and nucleic acid leakage, and membrane potential. The growth of L. monocytogenes in milk was effectively controlled with 10 μL/mL δ-cadinene, especially at 4 °C. In conclusion, treatment with δ-cadinene could be a potential strategy for controlling the contamination of foods by L. monocytogenes.