Inhibition of listeriolysin O and phosphatidylcholine-specific production in Listeria monocytogenes by subinhibitory concentrations of plant essential oils.
Successful infection by Listeria monocytogenes is dependent upon a range of bacterial extracellular proteins including a cytolysin termed listeriolysin O and phosphatidylcholine-specific phospholipase C. Five plant essential oils--bay, clove, cinnamon, nutmeg and thyme--significantly reduced the production of listeriolysin O by L. monocytogenes. The greatest change was observed after culture with oil of thyme, which reduced haemolysis to 52.1 haemolytic units (HU)/ml compared with 99.8 HU/ml observed with the control. Oil of clove was the only oil that also significantly reduced phosphatidylcholine-specific phospholipase C activity. These changes were observed despite the oils causing no change to the final bacterial concentration or total extracellular protein concentration.
*Department of Dietetics, Nutrition and Biological Sciences, Queen Margaret University College, Clerwood Terrace, Edinburgh EH12 8TS and †Department of Medical Microbiology, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG.
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Smith-Palmer
*Department of Dietetics, Nutrition and Biological Sciences, Queen Margaret University College, Clerwood Terrace, Edinburgh EH12 8TS and †Department of Medical Microbiology, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG.
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Stewart
*Department of Dietetics, Nutrition and Biological Sciences, Queen Margaret University College, Clerwood Terrace, Edinburgh EH12 8TS and †Department of Medical Microbiology, University of Edinburgh Medical School, Teviot Place, Edinburgh EH8 9AG.
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D001427:Bacterial Toxins; D002849:Chromatography, Gas; D002935:Cinnamomum zeylanicum; D005054:Eugenol; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006460:Hemolysin Proteins; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000378:metabolism*; D026323:Myristica; D009822:Oils, Volatile; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010938:Plant Oils / Q000032:analysis / Q000494:pharmacology*; D046930:Thymus Plant; D010738:Type C Phospholipases / Q000378:metabolism
D001427:Bacterial Toxins; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D009822:Oils, Volatile; D010713:Phosphatidylcholines; D010938:Plant Oils; D005054:Eugenol; C044113:pimenta oil; D010738:Type C Phospholipases; C038705:hlyA protein, Listeria monocytogenes