Monitoring Of Antimicrobial Effect of GC-MS Standardized Melaleuca alternifolia Oil (Tea Tree Oil) On Multidrug Resistant Uropathogens

Abstract

The aim of this work was to investigate antimicrobial action of tea tree oil (TTO) against multidrug resistant uropathogens. TTO was analysed by GC-MS studies. 16 compounds representing approximately 99% of the oil were characterized. The major compounds were Limonene, γ -Terpinene, α- Terpinene, Cineol and α- Terpinolene. Further the antimicrobial effect of whole TTO was tested against the isolated uropathogens like Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, P. mirabilis and Staphylococcus aureus. The antibacterial action of TTO was determined by disc diffusion method and MIC was determined by broth microdilution method. The ZOI (mm) and MIC (%) was in the range of 16±4 mm and 0.075% (v/v equivalent) for E. Coli; 20±2 mm and 0.03% for S. aureus; 19±2 mm and 0.10% for K. pneumoniae; 19±2 mm and 0.03% for Proteus mirabilis; 20±2 mm and 0.038% for Proteus vulgaris. TTO showed low MIC values and high growth inhibition zone diameter in comparison to broad spectrum antibiotics - erythromycin, ampicillin, kanamycin, streptomycin and gentamycin. The result of the bioassay showed that oil possesses potent antibacterial and bacteriostatic property. This paper reviews the classical methods commonly used for evaluation of antibacterial activity of TTO and gives an overview on the susceptibility of human pathogens towards TTO and their constituents.