念珠菌血症常见病原真菌对唑类药物耐药性的分子演化研究

近年来，致病性念珠菌对唑类药物的耐药性逐渐增多并常常引起念珠菌血症患者治疗失败，深入研究其耐药机制以及耐药性的演化规律，具有重要意义。基于申请者及所在小组以往关于致病性念珠菌对唑类药物耐药机制研究的结果，尤其是在参与完成我国重症患者病房（ICU）念珠菌血症病原菌的构成、耐唑类药物的念珠菌菌株的筛选并初步确定致病菌株分子演化规律的基础上，拟开展如下工作：第一，探讨药物作用靶酶基因、药物流出泵基因在分离自念珠菌血症的新出现的致病性念珠菌对唑类药物耐药中的作用；第二，利用基因转化、基因破坏、全基因组重测序和表达谱测序技术，研究分离自念珠菌血症的常见致病性念珠菌除药物作用靶酶基因、药物流出泵基因之外的对唑类药物耐药的新机制；第三，利用微卫星和多位点序列分型技术，阐明引起我国念珠菌血症的病原菌对唑类药物耐药性的演化规律。

Azole-resistance in pathogenic Candida spp., causing the poor prognosis and high mortality in candidemia patient, has been increased in recent years. Comprehensive study on resistant-mechanism and evolution of the resistant strains is particularly significant. Based on our previous research results in azole-resistance of Candida spp., especially in completing investigation of Candida spp. distribution, screening the isolates with azole-resistance, as well as defining the preliminary mechanisms of molecular evolution of pathogenic Candida spp. isolated from candidemia, the following issues will be conducted out in this proposal: first, to explore the role of ERG11 encoding the azole-target-enzyme and the genes encoding efflux pumps in azole-resistance of the emerging strains of Candida spp. isolated from candidemia patient; Second, by using gene disruption strategies, digital gene expression Tag profiling procedure, and genome sequencing approaches, to investigate the novel mechanisms of azole-resistance, besides ERG11 and efflux pump genes, in Candida spp. isolated from candidemia; Third, by microsatellite and multiple-locus sequence typing analysis, to determine the evolution mechanisms of azole-resistance in Candida spp. causing candidemia.