Neutral microepidemic evolution of bacterial pathogens
Neutral microepidemic evolution of bacterial pathogens
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DOI：
10.1073/pnas.0406993102
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发表时间：
2005-02-08
影响因子：
11.1
通讯作者：
Spratt, BG
中科院分区：
文献类型：
--
作者：
Fraser, C;Hanage, WP;Spratt, BG
了解细菌群体遗传学对于解释细菌群体对选择压力的反应至关重要，例如抗生素治疗或仅针对菌株子集的疫苗。传染性细菌的进化通过突变和局部重组发生，并受到流行病学和分子过程的影响。我们表明，观察到的人口的三个重要的人类病原体，肺炎链球菌，脑膜炎奈瑟氏菌和金黄色葡萄球菌的遗传结构，可以解释使用一个简单的进化模型，是基于中性突变漂移，重组调制，并纳入流行病传播的影响，在当地人群。这个中性的“微流行病”模型的预测被发现密切配合观察到的遗传相关性分布的细菌样本从他们的自然人口，它提供了估计的相对重组率，同意与经验估计。分析表明，出现中性细菌种群结构的重叠微流行病内集群的主机人口，并提供洞察这些集群的性质和大小分布。这些发现挑战了细菌病原体菌株在相对适合度上明显不同的假设。
Understanding bacterial population genetics is vital for interpreting the response of bacterial populations to selection pressures such as antibiotic treatment or vaccines targeted at only a subset of strains. The evolution of transmissible bacteria occurs by mutation and localized recombination and is influenced by epidemiological as well as molecular processes. We demonstrate that the observed population genetic structure of three important human pathogens, Streptococcus pneumoniae, Neisseria meningitidis, and Staphylococcus aureus, can be explained by using a simple evolutionary model that is based on neutral mutational drift, modulated by recombination, and which incorporates the impact of epidemic transmission in local populations. The predictions of this neutral "microepidemic" model are found to closely fit observed genetic relatedness distributions of bacteria sampled from their natural population, and it provides estimates of the relative rate of recombination that agree well with empirical estimates. The analysis suggests the emergence of neutral bacterial population structure from overlapping microepidemics within clustered host populations and provides insight into the nature and size distribution of these clusters. These findings challenge the assumption that strains of bacterial pathogens differ markedly in relative fitness.