ERG11和ERG3基因突变与念珠菌对氟康唑耐药的关系

Genetic Mutation of ERG11 and ERG3 and the Relation Between Candida and Fluconazole Resistance

目的探讨热带念珠菌、白念珠菌的ERG3、ERG11基因突变与其对唑类抗真菌药物耐药的关系,以初步探讨热带念珠菌对唑类药物耐药的机制。方法收集本院2015年3月-2016年10月期间临床分离的念珠菌52株,经体外药敏试验得到耐氟康唑的热带念珠菌6株、白色念珠菌1株;提取基因组DNA,通过PCR分别扩增6株热带念珠菌与1株白色念珠菌ERG11、ERG3基因,将扩增后的产物分别进行双向测序;将测序结果与热带假丝酵母菌标准菌株、白色念珠菌标准株的序列通过BLAST比对分析,找出突变基因。结果 6株热带念珠菌ERG11基因序列共发现3个同义突变与2个错义突变,ERG3基因共发现4个同义突变,6个错义突变;1株白色念珠菌耐药株ERG11基因共发现2个同义突变与2个错义突变,ERG3基因共发现2个同义突变,未发现错义突变。结论耐药菌株ERG11或ERG3存在不同程度的突变,这些突变可能参与热带念珠菌、白念珠菌耐药性的形成。

Objective To study the relationship between ERG3 and ERG11 mutations of Candida tropicalis and Candida albicans and azole antifungal agents, and to explore the mechanism of Candida tropicalis resistance to azole drugs.Methods Collecting 52 strains of Candida albicans were isolated from March 2015 to October 2015, and 6 strains of Candida tropicalis and 1 strain of Candida albicans resistant to fluconazole were obtained by in vitro susceptibility test.Six strains of Candida tropicalis and 1 strain of Candida albicans ERG11 and ERG3 genes were amplified by PCR.The amplified products were sequenced.The sequencing results were compared to standard strain of Candida tropicalis and Candida albicans through the BLAST comparison analysis, finding the mutation genes.Results Three synonymous mutation sites and 2 missense mutations were found in 6 strains of Candida tropicalis in the ERG11 gene sequences.Four synonymous mutations and 6 missense mutations were found in the ERG3 gene.One Candida albicans have 2 synonymous mutations and 2 missense mutations in the ERG11 genes.Two synonymous mutations were found in the ERG3 genes, and no missense mutations were found.Conclusion There are different degree of mutations in ERG11 or ERG3, which may be involved in the formation of Candida tropicalis and Candida albicans resistance.