白假丝酵母临床分离株基因分型与药敏分析

Genotyping and antifungal susceptibility analysis of Candida albicans isolates

目的分析上海交通大学医学院附属瑞金医院白假丝酵母的基因分型情况以及不同基因型白假丝酵母的药敏结果。方法采用聚合酶链反应(PCR)扩增白假丝酵母25S核糖体DNA基因的内含子区,可转座Ⅰ型内含子插入片段的数目及大小的不同使得扩增产物不同,根据产物片段大小和数目分型。采用微量稀释法分析白假丝酵母抗真菌药物敏感性。结果171株白假丝酵母分为3型:A型93株,B型47株,C型31株。B型、C型白假丝酵母对唑类抗真菌药物的耐药率显著高于A型菌株,对氟胞嘧啶的耐药率低于A型菌株。结论白假丝酵母的PCR分型方法简便、快速、重复性好、特异性强;不同型别的白假丝酵母耐药谱有差异,对治疗中抗真菌药物的选择有一定的指导意义。

Objective To investigate genotype and antifungal susceptibility of Candida albicans isolated from Shanghai Jiaotong university medical college affiliated Ruijin hospital. Methods Polymerase chain reaction（PCR） designed to span the region that included the site of the transposable group I intron of 25S rDNA of Candida albicans was carried out. The size of the intron and the presence of insertion segments in the 25S rDNA were detected by agarose gel electrophoresis of PCR product. Microdilution method was carried out for antifungal susceptibility testing. Results A total of 171 strains of Candida albicans were divided into three types： 93 genotype A strains, 47 genotype B strains and 31 genotype C strains. The results of the antifungal susceptibility testing showed that strains of genotypes B and C were significantly more resistant for azole-drugs than strains of genotypeA, but more susceptible for flucytosine than strains of genotype A. Conclusions PCR genotyping method is simple and rapid, with high specificity and reproducibility. There is correlation between the Candida albicans genotypic groups and antifungal susceptibility.