白色假丝酵母菌对氟康唑耐药性及Erg11基因突变分析

Analysis of fluconazole resistance and Erg11 genetic mutations of Candida albicans

目的分析白色假丝酵母菌临床分离株对氟康唑的耐药性,阐明耐氟康唑白色假丝酵母菌Erg11基因突变。方法回顾性分析2011年6月-2012年12月医院患者送检各类标本分离的287株假丝酵母菌属,采用美国临床实验室标准化研究所(CLSI)M27-A3推荐的微量稀释法进行体外药敏试验,从177株白色假丝酵母菌中筛选出7株对氟康唑耐药株,对氟康唑靶酶基因Erg11进行PCR扩增、测序,与Genbank上标准序列(X13296)比对分析。结果在7株白色假丝酵母菌氟康唑耐药株和1株敏感株中共发现25个点突变,其中15个同义突变,10个错义突变,10个错义突变分别为V51G、Y53H、C75W、Y79D、V94G、D116E、K119N、K128T、D153E、E266D,其中V51G、Y53H、C75W、Y79D、V94G是新发现的。结论成功分析了白色假丝酵母菌对氟康唑耐药性及Erg11基因突变。

OBJECTIVE To analyze the resistance against fluconazole of clinical isolates of Candida albicans ,and clarify Erg11 gene mutations of fluconazole‐resistant C .albicans .METHODS Totally 287 Candida strains isolated from a variety of clinical specimens during Jun . 2011 - Dec . 2012 were retrospectively analyzed . In vitro susceptibility testing was conducted by broth microdilution test according to the clinical and laboratory standards institute （CLSI） methods M27‐A3 .Totally 7 fluconazole‐resistant strains were screened from 177 C . albicans . The Erg11 gene of fluconazole target enzymes were amplified by PCR and were directly sequenced ,then Erg11 was compared with the Genbank standard sequence （X13296） .RESULTS A total of 25 point mutations were found in 7 fluconazole‐resistant strains and 1 fluconazole‐sensitive strain ,including 15 synonymous mutations and 10 missense mutations .The 10 missense mutations included V51G ,Y53H ,C75W ,Y79D ,V94G ,D116E ,K119N , K128T ,D153E , and E266D , of which 5 mutations （V51G , Y53H , C75W , Y79D , V94G ） were novel . CONCLUSION The fluconazole resistance and the mutations of Erg 11 of C .albicans were successfully analyzed .