Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
Proc Biol Sci. 2010 Jun 7;277(1688):1635-41. doi: 10.1098/rspb.2009.2033. Epub 2010 Feb 3.
Most studies of bacterial pathogen populations have been based on isolates collected from individuals with disease, or their contacts, over short time periods. For commensal organisms that occasionally cause disease, such as Neisseria meningitidis, however, the analysis of isolates from long-term asymptomatic carriage is necessary to elucidate their evolution and population structure. Here, we use mathematical models to analyse the structuring and dynamics of three vaccine-candidate antigens among carried meningococcal isolates collected over nearly 30 years in the Czech Republic. The data indicate that stable combinations of antigenic alleles were maintained over this time period despite evidence for high rates of recombination, consistent with theoretical models in which strong immune selection can maintain non-overlapping combinations of antigenic determinants in the presence of recombination. We contrast this antigenic structure with the overlapping but relatively stable combinations of the housekeeping genes observed among the same isolates, and use a novel network approach to visualize these relationships.
大多数关于细菌病原体种群的研究都是基于在短时间内从患病个体或其接触者中收集的分离株进行的。然而，对于那些偶尔会引起疾病的共生生物，如脑膜炎奈瑟菌，分析来自长期无症状携带的分离株对于阐明它们的进化和种群结构是必要的。在这里，我们使用数学模型来分析近 30 年来在捷克共和国收集的携带脑膜炎球菌分离株中三种候选疫苗抗原的结构和动态。数据表明，尽管有证据表明重组率很高，但在存在重组的情况下，抗原等位基因的稳定组合在这段时间内得以维持，这与理论模型一致，即强烈的免疫选择可以在存在重组的情况下维持抗原决定簇的非重叠组合。我们将这种抗原结构与同一分离株中观察到的重叠但相对稳定的管家基因组合进行对比，并使用一种新的网络方法来可视化这些关系。
