一株临床耐氟康唑白念珠菌生物膜特性及耐药相关基因表达的初步研究  

Characterization of biofilm and drug resistance-related genes expression in a fluconazole-resistant Candida albicans clinical isolate

作　　者：张甲[1] 班传伟 刘晓明 魏军[3] 贾伟[3] ZHANG Jia BAN Chuan - wei LIU Xiao - ming WEI Jun JIA Wei(School of Clinical Medicine, Ningxia Medical University, Yinchuan, Ningxia 750021, China)

机构地区：[1]宁夏医科大学临床医学院,宁夏银川750004 [2]宁夏医学病原微生物重点实验室,宁夏银川750004 [3]宁夏医科大学总医院医学实验中心,宁夏银川750004

出　　处：《现代预防医学》2017年第15期2817-2822,共6页Modern Preventive Medicine

基　　金：宁夏临床病原微生物重点实验室开放课题(2015;LCPM201501-1);2015年宁夏研究生教育创新计划项目(2016;NXYC201511)

摘　　要：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 biofilm characteristics and possible mechanism of drug resistance in a fluconazole - resistant Candida albicans （ C. albicans） clinical isolate. Methods One clinical fluconazole resistant isolate and 15 clinical isolates of C. albicans were analyzed for the capacity of biofilm production using a fluorescence staining assay. A qRT - PCR assay was used to measure the expression of biofilm formation and drug resistance related genes HWP1, ALS3, ERGll, MDR, CDR1 and CMP1. Results This fluconazole resistant C. albicans isolate showed a moderate biofilm - producing - ability. The qRT - PCR results showed that the expression of biofilm formation - related genes HWP1, ALS3 were lower to some degree in the fluconazole - resistant isolate compared to fluconazole - sensitive clinical isolates. However, the expression of ERG11, CDR1 and CMP1 genes were significantly elevated in the fluconazole - resistant C. albicans isolate compared to fluconazole - sensitive clinical isolates（ P 〈 0. 05 ）. Importantly, when FLC and CSA were used together, the expression of drug - resistant genes ERG11, MDR, CMP1 and CDR1 decreased compared to fluconazole alone in this fluconazole - resistant C. albicans isolate（ P 〈 0. 05）. Conclusion Biofilm formation may not be the main factor of the drug resistance in the clinical fluconazole - resistant C. albicans isolate. Instead, an evoked expression of drug - resistant genes ERG11, efflux genes CDR1 and calcineurin genes CMPlmay be a main mechanism accounting for the drug resistance. Of interest, a combination of CSA significantly increased the susceptibility of this drug - resistant isolate to fluconazole, which was most likely through a molecular mechanism by down - regulating the expression of the drug target enzymes and efflux pump genes.

关 键 词：白念珠菌 氟康唑 耐药性 生物膜 环胞菌素A 

分 类 号：R117[医药卫生—公共卫生与预防医学]