我国新生隐球菌临床株基因型分析

Genotype Analysis of Cryptoccocus neoformans Clinical Strains in Mainland China

摘要:

为了解中国大陆地区新生隐球菌临床株基因型分布情况, 我们对来自我国中东部地区的18个省、直辖市的120株血清A型和9株血清B型新生隐球菌临床株采用PCR指纹分析、IGS序列测定和MLST(Multilocus sequencing test)方法进行分析。结果显示血清A型菌株的M13指纹图谱中主要条带与VNI型标准株相同, 但次要条带与VNI现有各亚型均不相符, 我们将这种新VNI亚型命名为VNIc型, 但VNIc型并不只分布在中国大陆, MLST分析显示中国大陆地区的VNIc型菌株同来自美国、日本、马拉维和巴西的7株菌株亲缘关系高达75, 提示VNIc型可能是一种世界范围内分布的基因型; 对血清A型菌株采用(GACA)4和URA-5 RFLP指纹分析则呈现与VNI标准株完全一致的主次条带; 9株血清B型菌株基因型为VGI型。本研究初步揭示了我国大陆地区新生隐球菌临床株的基因型分布。

Abstract:

We analyzed the genotype of 120 Cryptococcus neoformans and 9 Cryptococcus gattii strains isolated from cryptococcosis patients residing in 16 provinces of mainland China, using methods of DNA fingerprint, IGS sequence, MLST and construction of dendrogram based on M13 fingerprint. 120 serotype A strains exhibited an identical M13-based VNI subtype, which was distinguishable from the reference VNI molecular type, MLST also showed the same result, for convenience we named this unique genotype VNIc. (GACA)4 and URA-RFLP could not separate VNIc from other subtype of VNI. The 9 serotype B strains of C. gattii portrayed a typical VGI molecular type. This research showed that VNIc is responsible for the majority of clinical cryptococcosis in China.