北京市人类免疫缺陷病毒-1 B亚型分子的流行特征

Molecular epidemiological characteristics of human immunodeficiency virus-1 B strains in Beijing

目的分析北京市HIV-1B亚型的分子流行特征。方法采集北京市2006年至2010年新发现的HIV—1B亚型感染者抗凝血，反转录套式PCR扩增病毒gag基因，并进行系统进化和Entropy核苷酸多态性差异分析。结果成功扩增167份标本，其中欧美B亚型10份，B’亚型14份，中国B亚型101份。B’亚型进化簇内存存多条来自泰国和印度的序列，中国B亚型独立成簇，进化簇内无其他围家的序列。中国B亚型存在4个业簇，71．1％的病例为男男性传播。以欧美B进化簇为参照，B’亚型和中国B亚型进化簇分别存在55和94个有明显差异的核苷酸位点。结论北京市存在3种类型的HIV-1B亚型，其中1种为本土株。

Objective To analyze the molecular epidemiological characteristics of human immunodeficiency virus-1 （ HIV 1 ） B sublype strains in Beijing. Methods Plasma samples were collected from 200 newly diagnosed HIV 1 B subtype individuals reported during 2006 to 2010 in Beijing. The gag gene fragments were amplified from RNA template extracted from plasma using reverse transcriptation and nested polymerase chain reaction （PCR） methods and the sequences were analyzed by phylogenetic and Entropy analysis. Results A total of 167 sequences were successfully amplified from the gag genes. Phylogenetic analysis indicated that the subtype B sequences in Beijing could be grouped into three clades, which were named Europe and America B clade （10 sequences） , Br clade （54 sequences） and China B clade （101 sequences） based on the origin of the reference sequences. China clade was pure Chinese B subtype clade which did not contain any foreign slrains and it was segregated into four major distinct clusters, of which 71.1% individuals was men who have sex with men （MSM）. When compared with Europe and America clade, there were 55 and 94 significantly different nucleotides polymorphism composition sites in B＇clade and China clade, respectively. Conclusion Three main epidemic clades exist in HIV1 B strains in Beijing, including one local China B clade.