In vitro activity of Citrus bergamia (bergamot) oil against clinical isolates of dermatophytes

Abstract

Objectives: Recently, bergamot oil was shown to be a potent antifungal agent in vitro against clinically important Candida species. In this study, the activities of bergamot natural essence and its furocoumarin-free and distilled extracts on dermatophytes such as Trichophyton, Microsporum and Epidermophyton species were investigated. Methods: In vitro susceptibility testing assays on 92 clinical isolatesof dermatophytes (Trichophyton mentagrophytes n = 20, Trichophyton rubrum n = 18, Trichophyton interdigitale n = 15, Trichophyton tonsurans n = 2, Microsporum canis n = 24, Microsporum gypseum n = 1 and Epidermophyton floccosum n = 12) were performed using the CLSI M38-A broth microdilution method, except for employing an inoculum of 1-3 × 103 cfu/mL. MICs were determined at a visual endpoint reading of 80% inhibition compared with the growth control. Results: MICs (v/v) of all fungi ranged from 0.156% to 2.5% for the natural essence, from 0.02% to 2.5% for the distilled extract, and from 0.08% to 1.25% for the furocoumarin-free extract. The three isolates of T. tonsurans and M. gypseum exhibited the highest MIC values. Conclusions: Data from this study indicate that bergamot oil is active in vitro against several common species of dermatophytes, suggesting its potential use for topical treatment of dermatophytoses. © The Author 2006. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.