Membrane toxicity of antimicrobial compounds from essential oils.
Natural antimicrobial compounds perform their action mainly against cell membranes. The aim of this work was to evaluate the interaction, meant as a mechanism of action, of essential oil antimicrobial compounds with the microbial cell envelope. The lipid profiles of Escherichia coli O157:H7, Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Pseudomonas fluorescens, and Brochothrix thermosphacta cells treated with thymol, carvacrol, limonene, eugenol, and cinnamaldehyde have been analyzed by gas chromatography. In line with the fatty acids analysis, the treated cells were also observed by scanning electron microscopy (SEM) to evaluate structural alterations. The overall results showed a strong decrease of the unsaturated fatty acids (UFAs) for the treated cells; in particular, the C18:2trans and C18:3cis underwent a notable reduction contributing to the total UFA decreases, while the saturated fatty acid C17:0 raised the highest concentration in cinnamaldehyde-treated cells. SEM images showed that the used antimicrobial compounds quickly exerted their antimicrobial activities, determining structural alterations of the cell envelope.
Di Pasqua
Rosangela
R
Department of Food Science, Division of Microbiology, University of Naples Federico II, Via Università 100, 80055 Portici, Italy.
Betts
Gail
G
Hoskins
Nikki
N
Edwards
Mike
M
Ercolini
Danilo
D
Mauriello
Gianluigi
G
D000890:Anti-Infective Agents / Q000633:toxicity*; D001419:Bacteria / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects; D019453:Escherichia coli O157 / Q000187:drug effects / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009822:Oils, Volatile / Q000737:chemistry*; D011551:Pseudomonas fluorescens / Q000187:drug effects / Q000648:ultrastructure; D012486:Salmonella typhimurium / Q000187:drug effects / Q000648:ultrastructure; D013211:Staphylococcus aureus / Q000187:drug effects / Q000648:ultrastructure
D000890:Anti-Infective Agents; D009822:Oils, Volatile