Antibacterial Activity of Herbal Essential Oils against Gram-positive and Gram-negative Bacteria with a Potential for Multidrug Resistance

Abstract

Background: In recent years, there has been an extensive and great interest in researching and developing alternative antibacterial agents from various sources to combat bacterial resistance. Therefore, greater attention has been paid to the screening of antibacterial activity. Aims: This study evaluated different types of herbal essential oil to inhibit the growth of selected human pathogenic bacteria with potential multidrug resistance properties. Methodology: The herbal essential oils used include thyme oil, tea tree oil, bergamot oil and lavender oil against Staphylococcus aureus, Escherichia coli and Bacillus subtilis. Antibacterial screening of all the essential oils was done by disk diffusion method. Results: Herbal essential oils have exhibited a broad spectrum of antibacterial activities against the selected microbes: B. subtilis, S. aureus and E. coli. Thyme oil has the most potential antibacterial properties for B. subtilis(40 mm), followed by S. aureus(35 mm) and E. coli(35 mm). Both bergamot and lavender oils showed higher antibacterial effects for E. coli and B. subtilis but have lower efficacy with S. aureus than tea tree oil. Conclusion: The herbal essential oils used in this study can serve as a source of alternative antibacterial agents and may play an important role in the discovery of new drugs for the treatment of a wide range of pathogenic bacteria in the future.