title: Membrane Destruction and DNA Binding of Staphylococcus aureus Cells Induced by Carvacrol and Its Combined Effect with a Pulsed Electric Field.
abstract: Carvacrol (5-isopropyl-2-methylphenol, CAR) is an antibacterial ingredient that occurs naturally in the leaves of the plant Origanum vulgare. The antimicrobial mechanism of CAR against Staphylococcus aureus ATCC 43300 was investigated in the study. Analysis of the membrane fatty acids by gas chromatography-mass spectrometry (GC-MS) showed that exposure to CAR at low concentrations induced a marked increase in the level of unbranched fatty acids (from 34.90 ± 1.77% to 62.37 ± 4.26%). Moreover, CAR at higher levels severely damaged the integrity and morphologies of the S. aureus cell membrane. The DNA-binding properties of CAR were also investigated using fluorescence, circular dichroism, molecular modeling, and atomic-force microscopy. The results showed that CAR bound to DNA via the minor-groove mode, mildly perturbed the DNA secondary structure, and induced DNA molecules to be aggregated. Furthermore, a combination of CAR with a pulsed-electric field was found to exhibit strong synergistic effects on S. aureus.
authors.forename: Lang-Hong
authors.initials: LH
authors.lastname: Wang
authors.forename: Man-Sheng
authors.initials: MS
authors.lastname: Wang
authors.forename: Xin-An
authors.initials: XA
authors.lastname: Zeng
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Zhang
authors.affiliation: School of Biological Sciences, The University of Auckland , Auckland 1142, New Zealand.
authors.forename: De-Ming
authors.initials: DM
authors.lastname: Gong
authors.forename: Yan-Bo
authors.initials: YB
authors.lastname: Huang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects*; D002942:Circular Dichroism; D000081007:Cymenes; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism; D004560:Electricity; D005519:Food Preservation / Q000379:methods*; D050296:Microbial Viability / Q000187:drug effects; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology*; D031341:Origanum / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D000081007:Cymenes; D004269:DNA, Bacterial; D039821:Monoterpenes; D010936:Plant Extracts; C073316:carvacrol
keywords: DNA binding; Staphylococcus aureus; gas chromatography−mass spectrometry; molecular modeling; synergistic effect