Mechanism of Action of Melaleuca alternifolia (Tea Tree) Oil on Staphylococcus aureus Determined by Time-Kill, Lysis, Leakage, and Salt Tolerance Assays and Electron Microscopy
AUTOR(ES)
Carson, Christine F.
FONTE
American Society for Microbiology
RESUMO
The essential oil of Melaleuca alternifolia (tea tree) has broad-spectrum antimicrobial activity. The mechanisms of action of tea tree oil and three of its components, 1,8-cineole, terpinen-4-ol, and α-terpineol, against Staphylococcus aureus ATCC 9144 were investigated. Treatment with these agents at their MICs and two times their MICs, particularly treatment with terpinen-4-ol and α-terpineol, reduced the viability of S. aureus. None of the agents caused lysis, as determined by measurement of the optical density at 620 nm, although cells became disproportionately sensitive to subsequent autolysis. Loss of 260-nm-absorbing material occurred after treatment with concentrations equivalent to the MIC, particularly after treatment with 1,8-cineole and α-terpineol. S. aureus organisms treated with tea tree oil or its components at the MIC or two times the MIC showed a significant loss of tolerance to NaCl. When the agents were tested at one-half the MIC, only 1,8-cineole significantly reduced the tolerance of S. aureus to NaCl. Electron microscopy of terpinen-4-ol-treated cells showed the formation of mesosomes and the loss of cytoplasmic contents. The predisposition to lysis, the loss of 260-nm-absorbing material, the loss of tolerance to NaCl, and the altered morphology seen by electron microscopy all suggest that tea tree oil and its components compromise the cytoplasmic membrane.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=127210Documentos Relacionados
- In Vitro Activities of Ketoconazole, Econazole, Miconazole, and Melaleuca alternifolia (Tea Tree) Oil against Malassezia Species
- In Vitro Susceptibilities of Lactobacilli and Organisms Associated with Bacterial Vaginosis to Melaleuca alternifolia (Tea Tree) Oil
- Electron Microscopy of Staphylococcus aureus Cell Wall Lysis
- Comparação da eficácia antimicrobiana de sabonetes contendo óleo essencial de Tea Tree (Melaleuca alternifolia) e triclosan na higienização de mãos artificialmente contaminadas
- Comparison of three different in vitro methods of detecting synergy: time-kill, checkerboard, and E test.