In vitro antifungal activity of essential oils extracted from plants against fluconazole-susceptible and -resistant Candida albicans

Candida albicans is more prevalent between Candida species which can cause candidal infection. Various studies have shown drug resistance among the C. albicans isolates, so it is now necessary to discover replacement treatments for the Candida infection. The aim of this study is comparison the effects of different Essential oils (EOs) against azoles-resistant and azoles-susceptible isolates.

Twenty fluconazole resistance and twenty susceptible C. albicans, obtained from oral, vaginal and cutaneous tissues of patients with Candidiasis were evaluated. The efficacy and MICs of Zataria multiflora, Geranium herbarum, Lavendula officinalis, Cuminum, cyminum, Allium heamanthoides and Artemisia sieberi EOs against C. albicans, were determined on the basis of a reference method for broth microdilution susceptibility testing of yeasts, suggested by CLSI-M27S4. After the period of inoculation, incubation and subculturation, the MICs compared to the control tubes, were determined.

The obtained MICs for Zataria multiflora, Geranium herbarum, Artemisia sieberi and Lavendula officinalis EOs were between 0.1-0.25 µl/ml (mean: 0.18µl/ml), 0.4-1.3µl/ml (mean: 0.83µl/ml) and 0.7-2.25 µl/ml (mean: 1.4µl/ml), 0.6-1.7 µl/ml (mean: 1.2µl/ml), Cuminum cyminum EO respectively. The result showed that Zataria multiflora EO is more efficient than other EOs against Candida species. There are no significant differences between different Candida trains to the EOs. Also, there were no significant differences in the MICs of these EOs against the azoles- resistant and azoles- susceptible isolates.

In this study, the anti-Candida effects of the six EO against both azoles- resistance and azoles-susceptible isolates were similar. Given the documented resistance of different Candida species to synthetic and chemical antifungals, these EOs are effective replacement treatments for cutaneous and mucosal Candida infections especially for resistant or recurrent cases.