Abstract
The antimicrobial activity of Manuka oil, a steam distillate from Leptospermum scoparium, was investigated, and it's MIC against ten kinds of microorganisms was determin ed. MICs against bacteria and fungi were measured by means of both two-fold dliution method and agar plate two-fold dilution method, respectively. MICs of Manuka oil against Staphylococcus aureus KCTC 1916 and Micrococcus luteus KCTC 1915, gram-positive microrganisms, were identical as 3.05 ${\mu}$g/ml, while it's antibacterial activity against gram-negative microrganisms such as Pseudomonas aeruginosa KCTC 2513, Escherichia coli KCFC 1682, Klebsiella pneunioniae KCTC 2001 or Proteus vulgaris KCTC 2433 was negligible(MIC: ${\geq}$ 1000 ${\mu}$g/ml), suggesting a high susceptibility of gram-positive bacteria to Manuka oil. In addition, MIC against Aspergillus niger KCTC 6077 was 24 ${\mu}$g/ml. and that against the other fungi, Tricophyton mentagrophytes KCTC 1374 and Candida albicans KCTC 1940 was ${\geq}$ 1000 ${\mu}$g/ml. When Manuka oil ointment was used in combination with other drugs. i.e.. gentamycin sulfate, chlotrimazol and hydrocortisone acetate, and diphenhydramine HCl and hydrocortisone acetate. it's antibacterial activity against Staphylococcus aureus KCTC 1916 was higher than Manuka oil ointment or other drugs alone. In conclusion, Manuka oil possesses a selective antibacterial activity against Staphylococcus aureus KCTC 1916, and can be used as a potent antibacterial agent against it.
