新疆地区白念珠菌基因型分析及其体外药物敏感性研究

摘要

目的 研究新疆地区汉族和维吾尔族患者来源的50株白念珠菌的基因型及其对两性霉素B,5-氟胞嘧啶、米卡芬净、伊曲康唑、氟康唑和咪康唑的体外敏感性.方法 采用PCR法扩增白念珠菌rDNA 25S的I类内含子包含区,根据扩增产物的大小判断基因型(A型为450bp,B型为840bp,C型为450bp和840bp).采用CLSI M27-A液基微量稀释法测定50株白念珠菌对上述6种抗真菌药的体外敏感性.结果 50株菌分为3种基因型,A型30株,B型和C型各10株.所有菌株对两性霉素B,5-氟胞嘧啶、米卡芬净和咪康唑的MIC值较低,MIC范围依次为0.25-0.5μg/mL,0.125-0.5μg/mL,≤0.03μg/mL,0.25-8μg/mL;对伊曲康唑和氟康唑的MIC值较高,MIC范围分别为0.25-8μg/mL,0.564 μg/mL.B型和C型对5-氟胞嘧啶的MIC值均为0.125μg/mL,对伊曲康唑和氟康唑的耐药率分别为84%,70%.不同族别来源的菌株基因型比较无显著差异(P>0.05),不同基因型菌株的抗真菌药物敏感性比较也无显著差异(P>0.05).结论 新疆地区白念珠菌分A,B,C三种基因型.汉族和维吾尔族患者来源的白念珠菌基因型及其对抗真菌药的敏感性以及基因型与种族间均无相关性.B型和C型对5-氟胞嘧啶高度敏感,所有菌株对伊曲康唑和氟康哇的耐药率较高.%Object To analyze the genotypes of 50 isolates of Candida albicans from Han and Uyghur patients in Xinjiang area and to understand the in vitro antifungal susceptibilities of these isolates against amphotericin B, flucytosine, micafungin, itraconazole, fluconazole and miconazole. Methods The genotypes were identifed by the size of PCR amplicons amplifined from the group Ⅰ intron contained region of 25S rDNA ofC. albicans :genotype A (450 bp) ,genotype B (840 bp) and genotype C (450 bp and 840 bp). In vitro antifungal susceptibilities of 50 strains to 6 kind of antifungal agents were determined by CLSI M27-A microdilution method. Results Fifty strains were classified into three genotypes,including 30 strains of type A and 10 strains of type B and C,all these strains showed lower MIC to amphotericin B,flucytosine,micafungi ,and miconazole ( MIC range:0.25-0.5 μg/mL,0. 125-0.25 μg/mL, ≤0.03 μg/mL, and 0.25-8 μg/mL, respectively), and higher MIC to itraconazole and fluconazole ( MIC range :0.25-8 μg/ mL and 0.5-64 μg/mL,respectively). The MIC of the genotype B and C strains to flucytosine was 0. 125 μg/mL. The resistant ratio of itraconazole and fluconazole were 84％ and 70％ , respectively. No statistical significance was found in the genotypes of the strains from different races ( P ＞ 0. 05 ) or different genotypic strains and antigungal susceptibilities ( P ＞ 0. 05 ). Conclusions C. albicans in Xinjiang area included 3 genotypes ( A, B and C). There was no correlation between the genotype and antifungal susceptibilities of C. albicans strains from Han and Uyghur patients. Nither did genotype and race. All strains were resistant to itraconazole and flucytosine, but genotype B and C showed high susceptibilities to flucytosine.