Antimicrobial Activity of Tea Tree oil against Pathogenic Bacteria and Comparison of Its Effectiveness with Eucalyptus Oil, Lemongrass Oil and Conventional Antibiotics

Abstract

Tea Tree oil (TTO) is known to have antibacterial effects and this study was aimed to determine the abilities to control pathogenic bacteria and also compared the antimicrobial effectiveness of Eucalyptus oil (ECO), Lemongrass oil (LGO) and antibiotics those are using for bacterial infection. This study of antimicrobial activity against ten pathogenic bacteria: Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, Proteus vulgaris, Aeromonas hydrophila, Escherichia coli, Streptococcus pneumoniae, Bacillus subtilis, Klebsiella pneumonia and Streptococcus agalactiae was done by Broth dilution method and Agar well diffusion method. The essential oils used in this study were commercially available. The inhibition of bacterial growth after 24 hours incubation exhibits greater results than 6 hours incubation in most of the cases. After 24 hours incubation, TTO showed minimum 96.94% against E. coli and maximum 100% inhibition against seven bacteria selected for this study whereas ECO showed minimum 37.02% against E. coli and maximum 100% inhibition against S. aureus, P. vulgaris and A. hydrophila and the another essential oil that is LGO exhibited minimum 69.08% against E. coli and maximum 100% inhibition against five bacteria chosen for this study. The inhibition zones from each extract were measured and an activity index was calculated from the mean zone sizes. All Essential oils showed some degree of antimicrobial properties with the highest activity index (1.6) being from TTO against S. agalactiae. At last, established a comparison between tea tree oil and some broad spectrum antibiotics using well diffusion method. Tea tree oil exhibited observable zone against all the bacteria contrariwise, among nine antibiotics only two of them showed noticeable zone of inhibition to all the bacteria tested. According to this study, TTO has demonstrated remarkable antibacterial activity which was more efficient than ECO and LGO and, moreover, it is expected that TTO will gradually take place of conventional antibiotics to treat bacterial infection.