目的 研究高温刺激下白念珠菌中反转录转座子的表达情况与耐药性产生的关系,探寻白念珠菌耐药的分子机制.方法 微量液基稀释法测定氟康唑对高温诱导的白念珠菌的最低抑菌浓度(minimal inhibitory concentration,MIC)；斑点法(spot assay)考察诱导菌株对药物的耐受能力；实时定量PCR (RT-PCR)方法检测诱导菌株中反转录转座子TCA4中开放阅读框的表达水平.结果 长期高温刺激能降低白念珠菌对氟康唑(16 μg/mL)的耐受能力；高温诱导菌株中反转录转座子TCA4中Orf19.2668和Orf19.2669的表达水平相比于亲本菌ATCC10231发生高表达.结论 高温刺激能使反转录转座子TCA4发生转座激活,反转录转座子TCA4的转座激活与白念珠菌耐药性形成相关,与此同时可能还有其他机制参与白念珠菌耐药性的形成.%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 (M19.2669) 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.
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