环孢菌素A增强氟康唑抗生物膜型白念珠菌的研究

Study of cyclosporine A enhanced susceptibility of biofim-producing Candida albicans to fluconazole

目的探讨钙调磷酸酶抑制剂环孢菌素A增强氟康唑抗生物膜型白念珠菌药物敏感性的可能分子机制。方法选取临床血流感染分离的生物膜型白念珠菌构建体外生物膜模型,采用荧光染色法定性观察生物膜的生长及形态,XTT法测定药物对生物膜型白念珠菌细胞活性的影响,并利用q RT-PCR检测耐药及黏附相关基因bla_(ALS3)、bla_(HWP1)、bla_(CDR1)、bla_(MDR)及bla_(ERG11)在m RNA表达水平的变化。结果从临床血流感染中分离获得一株强产生物被膜白念珠菌,命名为CA NX05;钙调磷酸酶抑制剂能够增强CA NX05菌株对氟康唑的敏感性。q RT-PCR结果显示,经两种药物联合处理后白念珠菌中bla_(ALS3)、bla_(HWP1)、bla_(CDR1)、bla_(MDR)和bla_(ERG11) m RNA表达量与两种药单独使用相比均显示不同程度明显降低,差异具有统计学意义(P<0.05)。结论钙调磷酸酶抑制剂能够增强生物被膜型白念珠菌对氟康唑的敏感性,其增敏机制可能是通过降低白念珠菌的外排泵和黏附相关基因的表达量实现。

Abstract Objective To investigate the molecular mechanism of calcineurin inhibitors cyclosporine A in enhancing the susceptibility of clinical biofim-producing Candida albicans （C. albicans） to fluconazole （FLC）. Methods A biofilm model was generated using a clinical biofilm-producing isolate of C. albicans isolated from bloodstream infections. The inhibition of biofilm formation of C. albicans was determined by a fluorescent microscopy assay, and viability of bacteria against agents was ascertained by an XTT method. The expression of drug-resistant and adhesive genes b/~ALS3, b/5/HwP1, b/~CDR1, b/~MOR and blaERG11 was evaluated by a qRT-PCR assay. Results A high biofilm-producing C. albicans strain was isolated from bloodstream infections, which was designated as CA NX05; Calcineurin inhibitors was found to be able to enhance the susceptibility of biofilm-producing C. albicans to FLC. In comparison with the treatment of calcineurin inhibitors or FLC alone, the expression of blaALS3, blaHWP1, blacDRl, blaMOR and blaERCH genes were dramatically down-regulated in the treatment of a combination of calcineurin inhibitors and FLC for the clinical biofilm-producing C. albicans isolate, which was statistically signifcant （P〈0.05）. Conclusion Calcineurin inhibitors could enhance the susceptibility of biofilm-producing C. albicans to FLC, which was likely through a molecular mechanism by down-regulating the expression of the efflux pump and adhesion associated genes in this bacterium species.