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目的探讨一株临床耐氟康唑白念珠菌生物膜特性及可能的耐药机制。方法选取临床分离的15株氟康唑敏感白念珠菌和1株耐氟康唑的白念珠菌,通过体外建膜比较各菌株产膜能力,荧光染色观察生物膜的生长。并利用qRT-PCR检测生物膜形成及耐药相关基因HWP1、ALS3、ERG11、MDR、CDR1及CMP1等在不同处理组中表达水平的变化。结果这株临床耐氟康唑白念珠菌产膜能力为中等;qRT-PCR检测显示,耐药菌株生物膜形成相关基因HWP1、ALS3相较于临床氟康唑敏感株均有不同程度的降低,而耐药相关基因ERG11、CDR1和CMP1表达量明显高于敏感菌株;当氟康唑和环胞菌素A联合处理耐药菌株后,该耐药菌株的耐药相关基因ERG11、CMP1、MDR和CDR1表达量与单独使用氟康唑时相比均有不同程度的降低,差异具有统计学意义(P<0.05)。结论生物膜的形成可能不是该临床耐氟康唑白念珠菌产生耐药性的主要因素,其主要机制可能是通过药物靶酶基因ERG11,外排泵基因CDR1和钙调神经磷酸酶基因CMP1的过度表达实现的,而环胞菌素A能够通过降低药物靶酶和外排泵基因的表达增强这株耐氟康唑白念珠菌对氟康唑的敏感性。
Objective To investigate the clinical characteristics of a biofilm resistant to fluconazole-resistant Candida albicans and its possible mechanism of drug resistance. Methods Fifteen clinical isolates of fluconazole-sensitive Candida albicans and one fluconazole-resistant Candida albicans were selected. The membrane-forming ability of each strain was compared by membrane in vitro. The growth of biofilm was observed by fluorescence staining. QRT-PCR was used to detect the changes of biofilm formation and the expression level of resistance-related genes HWP1, ALS3, ERG11, MDR, CDR1 and CMP1 in different treatment groups. Results The clinical efficacy of Candida albicans against fluconazole-producing Candida albicans was moderate. The results of qRT-PCR showed that the biofilm-forming genes HWP1 and ALS3 of resistant strains were lower than those of clinical fluconazole sensitive strains, While the expression levels of ERG11, CDR1 and CMP1 were significantly higher than those of the susceptible strains. When fluconazole and cyclosporin A combined treatment of resistant strains, the resistance-related genes ERG11, CMP1, MDR and The expression of CDR1 was significantly lower than that of fluconazole alone (P <0.05). Conclusion The formation of biofilm may not be the main factor of clinical drug resistance to fluconazole-resistant Candida albicans. The main mechanism may be through the drug target gene ERG11, efflux pump gene CDR1 and calcineurin gene CMP1 Overexpression of Cyclosporine A can enhance the susceptibility of fluconazole-resistant Candida albicans to fluconazole by decreasing the expression of drug target enzymes and efflux pump genes.