PDF(Pubmed)
Abstract：
Host-pathogen interactions can be influenced by the host microbiota, as the microbiota can facilitate or prevent pathogen infections. In addition, members of the microbiota can become virulent. Such pathobionts can cause co-infections when a pathogen infection alters the host immune system and triggers dysbiosis. Here we performed a theoretical investigation of how pathobiont co-infections affect the evolution of pathogen virulence. We explored the possibility that the likelihood of pathobiont co-infection depends on the evolving virulence of the pathogen. We found that, in contrast to the expectation from classical theory, increased virulence is not always selected for. For an increasing likelihood of co-infection with increasing pathogen virulence, we found scenario-specific selection for either increased or decreased virulence. Evolutionary changes, however, in pathogen virulence do not always translate into similar changes in combined virulence of the pathogen and the pathobiont. Only in one of the scenarios where pathobiont co-infection is triggered above a specific virulence level we found a reduction in combined virulence. This was not the case when the probability of pathobiont co-infection linearly increased with pathogen virulence. Taken together, our study draws attention to the possibility that host-microbiota interactions can be both the driver and the target of pathogen evolution. This article is part of the theme issue \'Sculpting the microbiome: how host factors determine and respond to microbial colonization\'.
摘要：
宿主-病原体相互作用可受宿主微生物群的影响，因为微生物群可以促进或预防病原体感染。此外,微生物群的成员可以变得有毒。当病原体感染改变宿主免疫系统并引发菌群失调时,此类病原体可引起共感染。在这里，我们对病原体共感染如何影响病原体毒力的进化进行了理论研究。我们探索了病原体共感染的可能性取决于病原体不断发展的毒力的可能性。我们发现,与古典理论的预期相反，并不总是选择增加的毒力。随着病原体毒力的增加，合并感染的可能性越来越大，我们发现了毒力增加或减少的特定场景选择。进化变化，然而,在病原体中，毒力并不总是转化为病原体和病原体的联合毒力的相似变化。仅在高于特定毒力水平的病原体共感染被触发的情况之一中，我们发现联合毒力降低。当病原体共感染的可能性随病原体毒力线性增加时，情况并非如此。一起来看,我们的研究提请注意宿主-微生物群相互作用可能既是病原体进化的驱动因素，也是病原体进化的目标。本文是“塑造微生物组：宿主因素如何决定和响应微生物定植”主题的一部分。
