Stable association between strains of Mycobacterium tuberculosis and their human host populations
Stable association between strains of Mycobacterium tuberculosis and their human host populations
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DOI：
10.1073/pnas.0305627101
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发表时间：
2004-04-06
影响因子：
11.1
通讯作者：
Small, PM
中科院分区：
文献类型：
--
作者：
Hirsh, AE;Tsolaki, AG;Small, PM
结核分枝杆菌几乎是世界各地的重要人类病原体。在这里，我们研究不同的结核分枝杆菌菌株是否感染不同的人群，以及尽管存在全球交通以及国际化城市中心不同病原体菌株的汇聚，但宿主和病原体种群之间的关联是否稳定。 100 株结核分枝杆菌最近的全球移动和传播历史是根据一项为期 12 年的结核病分子流行病学研究推断出来的。这些分离株之间的遗传关系是从大基因组缺失的分布中推断出来的，这些缺失通过 DNA 微阵列进行鉴定，并通过 PCR 和序列分析进行确认。这些缺失的系统发育分析表明它们是独特的事件多态性，并且水平基因转移在结核分枝杆菌中极其罕见。结合流行病学数据，系统发育揭示了三个大的系统发育地理区域。宿主的原籍地区可以预测他或她携带的结核病菌株，即使传播发生在原籍地区以外的国际大都市中心，这种关联仍然很强。自东亚和菲律宾结核分枝杆菌分支分化以来的大致年代测定表明，这些谱系在几个世纪前就已分化。因此，宿主和病原体种群之间的关联似乎高度稳定。
Mycobacterium tuberculosis is an important human pathogen in virtually every part of the world. Here we investigate whether distinct strains of M. tuberculosis infect different human populations and whether associations between host and pathogen populations are stable despite global traffic and the convergence of diverse strains of the pathogen in cosmopolitan urban centers. The recent global movement and transmission history of 100 M. tuberculosis isolates was inferred from a molecular epidemiologic study of tuberculosis that spans 12 years. Genetic relationships among these isolates were deduced from the distribution of large genomic deletions, which were identified by DNA microarray and confirmed by PCR and sequence analysis. Phylogenetic analysis of these deletions indicates that they are unique event polymorphisms and that horizontal gene transfer is extremely rare in M. tuberculosis. In conjunction with the epidemiological data, phylogenies reveal three large phylogeographic regions. A host's region of origin is predictive of the strain of tuberculosis he or she carries, and this association remains strong even when transmission takes place in a cosmopolitan urban center outside of the region of origin. Approximate dating of the time since divergence of East Asian and Philippine clades of M. tuberculosis suggests that these lineages diverged centuries ago. Thus, associations between host and pathogen populations appear to be highly stable.