中国致病格特隐球菌的基因亚型分析

目的 探讨中国致病格特隐球菌的基因亚型与世界范围内格特隐球菌的分子流行病学关系。方法 扩增受试格特隐球菌IGS1、PLB1和GEF1位点的部分可变区，检索GenBank上相应位点的序列信息，进行多位点的序列比对和系统发育分析。结果 ①我国VGⅠ基因型和α交配型菌株在3个位点的序列与以菌株WM276为代表的一种基因亚型相同，国内首株VGⅡ基因型和α交配型菌株的序列与温哥华岛致病株R272一致。②针对GEF1基因部分片段的聚类分析准确鉴定受试格特隐球菌的基因型和交配型。结论 中国致病格特隐球菌VGⅠ基因型与世界上分布较广的一种基因亚型相似，首株VGⅡ基因型菌株与温哥华岛致病性弱的VGⅡb基因亚型相似。

Subgenotyping analysis of pathogenic Cryptococcus gattii isolates from China

Objective To assess the subgenotypes of pathogenic Cryptococcus gattii isolates from China and to elucidate the epidemiological links between these domestic isolates and those from other parts of the world. Methods DNA was extracted from 9 clinical isolates of Ctyptococcus gattii from China. The partially variable regions of the three unlinked loci, namely IGS1, PLB1 and GEF1, were amplified and sequenced, and the bioinformation at these loci was obtained from GenBank for multi-locus sequences alignment and phylogenetic analysis. Results Of these 9 clinical isolates, 8 were genotype VG Ⅰ and mating type α with the same sequences at the tested regions as the reference strain WM276, which was a representative isolate of an independent subgenotype; 1 was of genotype VG Ⅱ and mating type α, which was the first report in China, with the tested sequences consistent with those of the referrence strain R272. Sequencing and phylogenetic analysis of GEF1 gene, which was located at mating type locus, successfully identified the genotypes and mating types of all the Cryptococcus gattii isolates involved here. Conclusions Multi-locus sequence analysis shows that causative Cryptococcus gattii isolates of genotype VG Ⅰ in China carry similar sequences at the tested loci in IGS1, PLB1 and GEF1 genes, to a widely distributed subgenotype in the world, and the sequences of the first VG Ⅱ genotype isolate from China resemble the less virulent subgenotype VG Ⅱ b found in Vancouver islands.