获得性免疫缺陷综合征患者的新生隐球菌基因多态性研究

Genetic polymorphisms of Cryptococcus neoformans isolates from patients infected with human immunodeficiency virus

本文旨在调查2003年1月?2007年12月分离自上海地区获得性免疫缺陷综合征(AIDS)患者的新生隐球菌临床株的配型及基因型分布特征,为隐球菌病的诊疗提供科学依据。首先以M13为单引物对模板DNA进行聚合酶链反应(PCR)扩增,参照标准株指纹图将临床株鉴定至基因型;同时对12株来自AIDS患者的新生隐球菌临床株的内转录间隔区(ITS)基因进行PCR扩增、序列分析,以CLUSTALW1.83软件多重比对分析ITS序列的差别,MEGA3.1软件处理数据,NJ法绘制系统进化树,Bootstrapping法对系统进化树结果进行统计学检验,区分新生隐球菌格鲁比变种、新生变种及格特变种菌株;最后选用特异性引物PCR特异性扩增相关基因,鉴定α和a配型。结果显示,分离自上海地区的12株隐球菌临床株中,9株(75%)为VNⅠ基因型/α配型菌株,3株(25%)为VNⅡ基因型/α配型菌株,且ITS基因序列分析可将各临床株鉴定至变种水平。本研究提示,分离自上海地区AIDS患者的新生隐球菌临床株存在一定的遗传多态性,以VNⅠ基因型/α配型菌株为主,有少量VNⅡ基因型/α配型菌株。

The present report was designed to determine the population structure of genotypes and mating type of Cryptococcus neoformans isolates from Chinese patients infected with human immunodeficiency virus （HIV） living in Shanghai. A total of 12 clinical Cryptococcus neoformans isolates were analyzed by internal transcribed spacer （ITS） sequence using CLUSTAL W1. 83 and MEGA3. 1 software. The phylogenetic tree was statistically tested via bootstrapping method, and molecular typing was analyzed via polymerase chain reaction （PCR）-fingerprinting with M13 oligonucleotide as a single primer. Mating type was determined by PCR using two specific primer pairs in accordance with Chaturvedi et al. The results showed that hinting-type α, VN Ⅰ molecular type （9/12, 75% ） is predominant in clinical Cryptococcus neoformans isolates from this group of patients. Our research provides new information on the genetic polymorphisms of Cryptococcus neoformans isolates from Shanghai, China.