1. Inhibitory effect and mechanism of oregano essential oil on Listeria monocytogenes cells, toxins and biofilms.
- Author
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Guo P, Li Z, Cai T, Guo D, Yang B, Zhang C, Shan Z, Wang X, Peng X, Liu G, Shi C, Alharbi M, and Alasmari AF
- Subjects
- Animals, Heat-Shock Proteins metabolism, Hemolysis drug effects, Swine, Adenosine Triphosphate metabolism, Membrane Potentials drug effects, Molecular Docking Simulation, Cymenes, Listeria monocytogenes drug effects, Biofilms drug effects, Biofilms growth & development, Oils, Volatile pharmacology, Oils, Volatile chemistry, Origanum chemistry, Microbial Sensitivity Tests, Hemolysin Proteins metabolism, Hemolysin Proteins antagonists & inhibitors, Hemolysin Proteins pharmacology, Bacterial Toxins metabolism, Bacterial Toxins antagonists & inhibitors, Reactive Oxygen Species metabolism, Anti-Bacterial Agents pharmacology
- Abstract
Listeria monocytogenes (L. monocytogenes) is a prevalent foodborne pathogen with a remarkable capacity to form biofilms on utensil surfaces. The Listeriolysin O (LLO) exhibits hemolytic activity, which is responsible for causing human infections. In this study, we investigated the inhibitory effect and mechanism of oregano essential oil (OEO) on L. monocytogenes, evaluated the effects on its biofilm removal and hemolytic activity. The minimum inhibitory concentration (MIC) of OEO against L. monocytogenes was 0.03 % (v/v). L. monocytogenes was treated with OEO at 3/2 MIC for 30 min the bacteria was decreased below the detection limit (10 CFU/mL) in PBS and TSB (the initial bacterial load was about 6.5 log CFU/mL). The level of L. monocytogenes in minced pork co-cultured with OEO (15 MIC) about 2.5 log CFU/g lower than that in the untreated group. The inhibitory mechanisms of OEO against planktonic L. monocytogenes encompassed perturbation of cellular morphology, elevation in reactive oxygen species levels, augmentation of lipid oxidation extent, hyperpolarization of membrane potential, and reduction in intracellular ATP concentration. In addition, OEO reduced biofilm coverage on the surface of glass slides by 62.03 % compared with the untreated group. Meanwhile, OEO (1/8 MIC) treatment reduced the hemolytic activity of L. monocytogenes to 24.6 % compared with the positive control. Molecular docking suggested carvacrol and thymol might reduce the hemolytic activity of L. monocytogenes. The results of this study demonstrate that OEO exhibits inhibitory effects against L. monocytogenes, biofilms and LLO, which had potential as natural antimicrobial for the inhibition of L. monocytogenes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interest or personal relationship that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
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