Antifungal Activity of Select Essential Oils against Candida auris and Their Interactions with Antifungal Drugs

Abstract

Candida auris is an emerging fungal pathogen that commonly causes nosocomial blood infections in the immunocompromised. Several factors make this pathogen a global threat, including its misidentification as closely related species, its ability to survive for weeks on fomites, and its resistance to commonly prescribed antifungal drugs, sometimes to all three classes of systemic antifungal drugs. These factors demonstrate a need for the development of novel therapeutic approaches to combat this pathogen. In the present study, the antifungal activities of 21 essential oils were tested against C. auris. Several essential oils were observed to inhibit the growth and kill C. auris, Candida lusitaniae, and Saccharomyces cerevisiae when in direct contact and at concentrations considered safe for topical use. The most effective essential oils were those extracted from lemongrass, clove bud, and cinnamon bark. These essential oils also elicited antifungal activity in gaseous form. The efficacies of formulations comprised of these three essential oils in combination with fluconazole, amphotericin B, flucytosine, and micafungin were explored. While synergism was neither observed with cinnamon bark oil nor any of the antifungal drugs, lemongrass oil displayed synergistic, additive, and indifferent interactions with select drugs. Formulations of clove bud oil with amphotericin B resulted in antagonistic interactions but displayed synergistic interactions with fluconazole and flucytosine. These essential oils and their combinations with antifungal drugs may provide useful options for surface disinfection, skin sanitization, and possibly even the treatment of Candida infections.

Study of the Chemical Profile and Anti-Fungal Activity against Candida auris of Cinnamomum cassia Essential Oil and of Its Nano-Formulations Based on Polycaprolactone

“…Recently, several studies have been conducted in order to identify EOs potentially active against C. auris . Towards C. auris strains, several EOs have been shown to have antifungal effectiveness when used alone ( Cymbopogon citratus , Eugenia caryophyllata and Cinnamomum zeylanicum from bark) [ 16 , 38 ] or in nano formulations ( Lavandula angustifolia, and Lippia sidoides ) [ 23 , 24 ].…”

“…The essential oils (EOs) produced by the distillation of aromatic plants are, among the natural substances, the products with the highest antimicrobial potential [ 12 , 13 ]. Several studies have been recently published to evaluate the antifungal activity of EOs against C. auris and its biofilm [ 14 , 15 , 16 , 17 ], and the Cinamomum cassia EO (CC-EO) is one of the most powerful with its bioactive compound cinnamaldehyde [ 18 , 19 ]. C. cassia Presl is a tropical aromatic evergreen tree of the Lauraceae family, commonly used in traditional Chinese medicine.…”

Antifungal and Antibiofilm Activity of Colombian Essential Oils against Different Candida Strains

“…Secondary metabolites of MM-II EO, iso-menthone and menthone, were moderately correlated to antibiofilm activity exclusively against the C. auris strain. Moreover, other authors have evaluated the ability of EOs to inhibit or control the planktonic and sessile growth of C. auris with promising results [ 11 , 44 , 45 , 46 , 47 ]. However, most of those EOs (cinnamon, lemongrass, tea tree, cajeput, Niaouli, and White thyme) showed higher MICs (>375 µg/mL or >0.05% v / v) than those of our bioactive EOs [ 45 , 47 ].…”

Exploration of Clove Bud (Syzygium aromaticum) Essential Oil as a Novel Attractant against Bactrocera dorsalis (Hendel) and Its Safety Evaluation

“…Additionally, 2-nonanone and 2-undecanone have been reported to stimulate a strong antennal response and a positive oviposition response on C. capitata , acting as an attractant and oviposition stimulant [ 46 ]. Although the constituents of clove bud oils can differ, it is highly likely that eugenol is the primary component of clove EO, according to all reports [ 37 , 39 , 40 , 41 , 47 , 48 , 49 ]. Although the attractiveness of eugenol to B. dorsalis has not been reported, several of its analogous compounds have been characterized as male attractants and male sex pheromones of B. dorsalis [ 50 ].…”