Abstract: Objective To study the relationship between expression of retrotransposon TCA4 stimulated by high temperature (37℃) and resistance in Candida albicans strains, to explore the molecular mechanisms of drug-resistance in Candida albicans.Methods The minimal inhibitory concentrations (MICs) of stimulated Candida albicans strains to fluconazole were determined by broth microdilution method. Spot assay was performed to compare the resistance to miconazole and H₂O₂ between wild type and derivative strains. The total RNA of wild type and derivative strains were extracted, and the expression of the retrotransposon TCA4's ORFs (Orf19.2668 and Orf19.2669) were examined by real-time RT-PCR.Results Long-term exposure to high temperature enhanced the susceptible of Candida albicans to miconazole (2 μg/mL) and H₂O₂ (5 mmol/L);The incidences of Orf19.2668 and Orf19.2669 overexpression in strains induced by high temperature were significantly higher than those in parental strains ATCC-10231.Conclusion Fluconazole-resistance in Candida albicans strains is related to the transposition of retrotransposons TCA4. At the same time there may be other mechanisms involved in the formation of drug resistance in Candida albicans strains.

Key words: Candida albicans, miconzole, retrotransposon, fungal drug resistance