Origin and evolutionary history of HIV-1 subtype C in Brazil
Origin and evolutionary history of HIV-1 subtype C in Brazil
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DOI：
10.1097/qad.0b013e328315e0aa
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发表时间：
2008-10-01
期刊：
影响因子：
3.8
通讯作者：
Morgado, Mariza G.
中科院分区：
文献类型：
--
作者：
Bello, Gonzalo;Passaes, Caroline P. B.;Morgado, Mariza G.
目的：调查巴西HIV - 1 C亚型流行的起源并重建其起始日期。
设计：对15年间（1991 - 2006年）从巴西南部HIV - 1阳性患者中分离出的C亚型序列的三个独立数据集进行了分析：82个env V3序列（213个核苷酸）、40个env C2 - C5序列（559个核苷酸）以及72个pol序列（960个核苷酸）。
方法：使用基本局部比对搜索工具、系统发育分析以及特定氨基酸特征模式搜索，将巴西的序列与数据库中的其他C亚型参考毒株进行比较。在严格或宽松的分子钟模型下，使用基于贝叶斯合并的方法估计进化参数。
结果：来自巴西和布隆迪的HIV - 1 C亚型序列在env和pol区域均形成一个单系簇，并且与来自世界各地的同亚型其他病毒相比，在蛋白酶区域具有特定的氨基酸特征。所有巴西毒株在布隆迪 - 巴西谱系内作为一个单系亚簇出现，而来自布隆迪的分离株出现在该分支的起源处。对env和pol基因组区域的进化分析表明，巴西C亚型分支最近共同祖先的年代可追溯到20世纪80年代早期。
结论：巴西南部地区的C亚型流行是由引入一种与布隆迪C亚型毒株密切相关的单一奠基者毒株引发的。我们的结果表明，这一奠基事件可能发生在20世纪80年代早期左右，比之前的估计大约早十年。（c）2008年，威科集团 | 利平科特·威廉姆斯和威尔金斯出版社。
Objective: To investigate the origin and to reconstruct the onset date of the HIV-1 subtype C epidemic in Brazil.Design: Three independent datasets of subtype C sequences isolated from HIV-1-positive patients from southern Brazil over a period of 15 years (1991-2006) were analyzed: 82 env V3 sequences (213nt), 40 env C2-C5 sequences (559nt), and 72 pol sequences (960nt).Methods: Brazilian sequences were compared with other subtype C reference strains from the database using basic local alignment search tool, phylogenetic analyses, and searching of specific amino acid signature patterns. Evolutionary parameters were estimated using a Bayesian coalescent-based method under either strict or relaxed molecular clock models.Results: HIV-1 subtype C sequences from Brazil and Burundi formed a monophyletic cluster at both env and pol regions and shared specific amino acid signatures in the protease region when compared with other viruses of the same subtype from around the world. All Brazilian strains arose as a monophyletic subcluster within the Burundi-Brazilian lineage, whereas isolates from Burundi appeared at the origin of the clade. Evolutionary analyses of both env and pol genomic regions indicate that the age of the most recent common ancestor of the Brazilian subtype C clade dates back to the early 1980s.Conclusion: The subtype C epidemic in the southern Brazilian region was initiated by the introduction of a single founder strain closely related to subtype C strains from Burundi. Our results suggest that this founder event probably took place around the early 1980s, roughly a decade before the previous estimates. (c) 2008 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.