Objective: The objective of this study was to compare the antimicrobial efficacy of several lavender oils, used singly and in combination, on methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA).
Methods: Four chemically characterized essential oils from Lavandula angustifolia, L. latifolia, L. stoechas, and a necrodane-rich L. luisieri were assessed for their antibacterial activity using the disc diffusion method.
Results: All four lavender oils inhibited growth of both MSSA and MRSA by direct contact but not in the vapor phase. Inhibition zones ranged from 8 to 30 mm in diameter at oil doses ranging from 1 to 20 microL, respectively, demonstrating a dose response. At any single dose, the extent of inhibition was very similar irrespective of the chemical composition of the oils or the strain of S. aureus used. Several binary combinations of the oils were tested, and the results showed that the necrodane-rich L. luisieri oil interacted synergistically with L. stoechas (high in 1,8-cineole, fenchone, and camphor) and L. langustifolia (rich in linalool and linalyl acetate) to produce larger inhibition zones than those produced using each oil individually.
Conclusions: The results suggest that combinations of lavender oils should be investigated further for possible use in antibacterial products.