安徽省耐唑类药物白念珠菌ERG11基因的突变研究

Research of the ERG11 mutations in azole-resistant Candida albicans in Anhui province

目的了解安徽省临床分离的对唑类药物(氟康唑﹑伊曲康唑﹑伏立康唑)耐药白念珠菌的ERG11基因突变情况,探讨其与耐药的关系。方法用沙保弱培养基对安徽省40所医院2012年9月份收集的198株白念珠菌进行培养﹑分离,科玛嘉显色培养基进行鉴定。采用微量稀释法测定其对唑类药物的敏感性,提取筛选出耐药的菌株及3株敏感株的基因组DNA,设计一对引物扩增其ERG11基因,扩增后送之测序,测序结果与GenBank中的已知标准序列(X13296)进行比对分析。结果 PCR产物电泳后均成功获得预期大小的片段,测序结果比对分析发现34个不同的碱基突变位点,其中错义突变位点为14个。结论本研究发现耐唑类药物的白念珠菌存在多个错义突变位点,且多为多位点突变,可能与其耐药性的产生有关,其中T123I、Y334S、V452D和L480F目前尚未见相关报道。

Objective To investigate the mutations of ERGll gene and its relationship with azole-resistant strains of Candida albicans isolated from the clinical specimens in Anhui province. Methods 198 strains selected from 40 hospitals of Anhui in September 2012 were cultured and isolated on Sabouraud＇s medium. CHROMagar Candida was used for identification. The MICs of Candida albicans were determined by Agar broth microdilution method. Genome DNA of the resistant strains and 3 sensitive strains was extracted. One pair of PCR primers was designed and used to amplify ERG11 gene. The PCR products were sequenced, and the analysed results were compared with the standard sequence（X13296） in GenBank. Results The size of all PCR fragments was consistant with the expected. From the analysis of the sequencing results, we found 34 different base mutations, including 14 missense mutations. Conclusion The research found ERG11 gene of the azole-resistant Candida albicans had many missense mutations, and many of them were multiple point mutations, which may be connected with drug-resistance in Candida albicans. T123L Y334S, V452D and L480F have not been reported at home and abroad.