Studies On Resistant Induction Of Candida Albicans To Lisea Cubeba Oil In Vitro

Objective To investigate whether it's likely to induce Lisea cubeba oil-resistant Candida albicans mutations in vitro, in order to give further evaluations of its antifungal actions for clinical use. Methods 1.A Candida albicans strain BMU00270 was induced by serial subcultures on agar medium containing different concentrations of Lisea cubeba oil (equivalent to 1MIC-100MIC), and 3 groups were set as control groups which were fluconazole group (positive control), 1.5% alcohol group(solvent control), drug-free group, respectively. The susceptibilities (MIC) of this parental strain and its respective derivatives to Lisea cubeba oil and fluconazole were measured. 2 .The induced less susceptible derivatives were subcultured on drug-free medium for 10 times consecutively, then their MICs were tested. 3.The MIC of induced fluconazole less susceptible derivative to Lisea cubeba oil was also measured. 4.The minimum fungicidal concentrations (MFCs) of Lisea cubeba oil and fluconazole against BMU00270 were determined. Results 1.After subcultured to the medium containing 20MIC (equivalent to 462.6 n g/ml ) Lisea cubeba oil, there was no viable colony would be seen. No Lisea cubeba oil-resistant mutants could be induced (the MICs of serial subcultrues were similar to that of the parental one). We didn't find any significant changes of MICs in 1.5% alcohol group and drug-free group, either. While the strain could acquire some resistance to fluconazole (up to 16-fold the parental MIC, designated FR)with the increase of inducing passages. 2. After FR was subcultured repeatedly on drug-free medium, we got FR1 which showed no significant MIC difference with FR. 3.The MIC of FR to Lisea cubeba oil was still the same as the parental one. 4.The MFC of Lisea cubeba oil was 370 μ g/ml, while fluconazole exhibited no fungicidal action in the present study. Conclusion We couldn't see the resistance to Lisea cubeba oil in our experiment of induction, moreover, fluconazole less susceptible derivative was still sensitive to Lisea cubeba oil. Lisea cubeba oil is a potential antifungal Chinese herb, and might be used for the treatment in Candidiasis.