Transmission bottlenecks as determinants of virulence in rapidly evolving pathogens
Transmission bottlenecks as determinants of virulence in rapidly evolving pathogens
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DOI：
10.1073/pnas.96.9.5095
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发表时间：
1999-04-27
影响因子：
11.1
通讯作者：
Real, LA
中科院分区：
文献类型：
--
作者：
Bergstrom, CT;McElhany, P;Real, LA
传播瓶颈发生在病原体群体中，即在新感染开始时，只有少数个别病原体从一个受感染宿主传播到另一个宿主。传播瓶颈可以极大地影响迅速进化的病原体（如RNA病毒）的毒力演变。用准物种概念描述病原体多样性，我们使用分析和模拟方法来证明，严重的瓶颈可能会导致病原体的毒力下降，因为最具毒力的病原体会随机丧失，这一过程类似于穆勒棘轮。我们研究了宿主种群大小、宿主内病毒复制持续时间和传播瓶颈大小在这一过程中的作用。我们认为有害突变的积累模式可以解释垂直和水平传播疾病的不同毒力水平。
Transmission bottlenecks occur in pathogen populations when only a few individual pathogens are transmitted from one infected host to another in the initiation of a new infection. Transmission bottlenecks can dramatically affect the evolution of virulence in rapidly evolving pathogens such as RNA viruses. Characterizing pathogen diversity with the quasispecies concept, we use analytical and simulation methods to demonstrate that severe bottlenecks are likely to drive dean the virulence of a pathogen because of stochastic loss of the most virulent pathotypes, through a process analogous to Muller's ratchet. We investigate in this process the roles of host population size, duration of within-host viral replication, and transmission bottleneck size. We argue that the patterns of accumulation of deleterious mutation may explain differing levels of virulence in vertically and horizontally transmitted diseases.