Antifungal activity of essential oils of lemon balm, manuka and tansy to the causative agents of otomycosis

Introduction: Otomycosis is a superficial fungal infection of the external ear canal. One of the therapeutic approaches that became topical in treatment of otomycosis is the application of essential oils, which is shown to have different biological properties, including the antimicrobial effect. Aim: The objective of the research is to examine antimycotic effects of essential oils of lemon balm (Melissa officinalis), manuka (Leptospermum scoparium) and tansy (Tanacetum vulgare) on the causative agents of otomycosis. Materials and Methods: In this study, we investigated the sensitivity of 20 randomly selected strains of Candida spp. and Aspergillus spp. isolated from swabs taken from the external ear canal of patients with signs and symptoms of otitis externa. Antifungal activity of essential oils of lemon balm, manuka and tansy was tested by using the microdilution method by determining the value of the Minimum inhibitory concentration (MIC) and Minimum fungicidal concentration (MFC). Results: MIC values of lemon balm were in the range of 0.39- 50 μl/ml, manuka of 0.39-50 μL/mL and tansy of 1.56-50 μL/mL. The MFC values were 2-4 times higher than the MIC values, except in the case of a strain of Aspergillus niger, which was tolerant of the lemon balm essential oil. Conclusion: The investigation has shown that essential oil activities of lemon balm, manuka and tansy to the strains of Candida spp. and Aspergillus spp, using the microdilution method, have antifungal effect.