Synergistic Effect of Essential Oils of Cymbopogon citratus (Lemon grass) and Zingiber officinale (Ginger) on Staphylococcus aureus, Salmonella typhi and Escherichia coli

Abstract

Essential oils obtained from Lemon grass (Cymbopogon citratus) and Ginger (Zingiber officinale) are used in combined form as herbal for various diseases. Synergistic antibacterial activity of essential oils of Cymbopogon citratus (Lemon grass) and Zingiber officinale (Ginger) on Staphylococcus aureus, Salmonella typhi and Escherichia coli was determined. The study aimed to determine the synergistic antibacterial effect of combination of lemon grass and ginger essential oils by using different ratios. The essentials oils were obtained by steam distillation from each of the plants. The essential oils of each as well as their combinations were tested against the three bacteria by employing agar well diffusion techniques. The results showed that each oil separately exhibited antibacterial activity ranging from zone of inhibition of 8.35mm to 23.90mm with varying concentrations of the oils. Lemon grass oil showed higher antibacterial activity of 23.9mm against Staph aureus but only 9.00mm against Salmonella typhi. The combined synergistic effect achieved on Staph aureus was 45mm, using ratio 1:1 and Salmonella typhi 35.00mm. The MIC and MBC for staph aureus were 20% and Escherichia coli with 12% MIC and MBC respectively. While Salmonella typhi were 10% and 8% respectively of MIC and MBC. The combination of essential oils of lemon grass and ginger exhibited good synergistic potential which can be utilized in formulation of drugs and preservatives.