The Antibacterial Effects of Several Plant Essential Oils on Staphylococcus aureus

Staphylococcus aureus is a bacterial pathogen associated with chronic antibiotic resistant infections. Antibiotic resistant strains of S. aureus are incredibly difficult to treat and may be transmitted between individuals in hospital and community settings. Certain plant essential oils have been shown to exert antibacterial effects on S. aureus, including the antibiotic resistant strains. In contrast to antibiotics that usually target one structural component of the cell, essential oils are thought to overcome the problem of bacterial resistance by exerting multi-component antibacterial effects. To determine the effect of seven different plant essential oils on S. aureus, disc diffusion and minimum inhibitory concentration assays were employed. Visual and spectrometric analysis indicated that red thyme (Thymus vulgaris) and cassia (Cinnamomum cassia) exhibited increased antibacterial effects on S. aureus in vitro. These essential oils likely target the cell wall of S. aureus causing irreversible damage and disruption of the proton motive force. The efficacy of essential oils against bacterial pathogens may thus present a much needed alternative to traditional antibiotic treatments