title: Effects of essential oil combinations on pathogenic yeasts and moulds.
abstract: Essential oils (EOs) can be used as alternative or complementary antifungal agents against human pathogenic moulds and yeasts. To reduce the effective dose of antimicrobial agents, EOs are combined which can lead to synergistic or additive effect. In this study the anti-yeast and anti-mould activities of selected EOs were investigated, alone and in combinations, against clinical isolates of Candida albicans, C. parapsilosis, Aspergillus fumigatus, A. terreus, Rhizopus microsporus, Fusarium solani and Lichtheimia corymbifera. Minimum inhibitory concentrations (MICs) were determined for the EOs of cinnamon, citronella, clove, spearmint and thyme. To investigate the combination effect of the EOs, fractional inhibitory concentrations (FICs) were defined by the checkerboard method and the type of interaction was determined by the FIC index (FICI). FIC index below 0.5 was considered as synergism and between 0.5 and 1 as additive effect. Strongest antifungal activity was showed by thyme EO with MIC values below 1.0 mg/ml. Combination of EOs resulted in additive or indifferent effect, with occasional "borderline synergism". The best combination was cinnamon with clove leading to additive effect in all cases.
authors.affiliation: Institute of Pharmacognosy, Faculty of Pharmacy, University of Pécs , Rókus u. 2, H-7624 Pécs , Hungary.
authors.forename: Györgyi
authors.initials: G
authors.lastname: Horváth
authors.affiliation: Institute of Food Engineering, Faculty of Engineering, University of Szeged , Mars tér 7, H-6724 Szeged , Hungary.
authors.forename: Julianna Török
authors.initials: JT
authors.lastname: Jenei
authors.affiliation: Department of Microbiology, Faculty of Science and Informatics, University of Szeged , Közép fasor 52, H-6726 Szeged , Hungary.
authors.forename: Csaba
authors.initials: C
authors.lastname: Vágvölgyi
authors.affiliation: Institute of Pharmacognosy, Faculty of Pharmacy, Semmelweis University , Üllői út 26, H-1085 Budapest , Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Böszörményi
authors.affiliation: Institute of Food Engineering, Faculty of Engineering, University of Szeged , Mars tér 7, H-6724 Szeged , Hungary.
authors.forename: Judit
authors.initials: J
authors.lastname: Krisch
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D009822:Oils, Volatile
keywords: Essential oils; combined effect; fractional inhibitory concentration; fungal pathogens