Within-Host Dynamics of Multi-Species Infections: Facilitation, Competition and Virulence
Within-Host Dynamics of Multi-Species Infections: Facilitation, Competition and Virulence
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DOI：
10.1371/journal.pone.0038730
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发表时间：
2012-06-21
期刊：
影响因子：
3.7
通讯作者：
Brown, Sam P.
中科院分区：
文献类型：
--
作者：
Eswarappa, Sandeepa M.;Estrela, Sylvie;Brown, Sam P.
宿主个体通常感染一种以上的寄生虫种类(广义定义的寄生虫，包括病毒和细菌)。然而，感染生物学的研究主要是对单寄生虫感染的研究。如果寄生虫之间的相互作用是相加的，那么关注单一寄生虫感染是合理的，然而，越来越多的证据表明，非相加相互作用是常态。在这里，我们回顾了这一证据，并从理论上探讨了共感染寄生虫之间的非相加相互作用的含义。我们使用经典的Lotka-Volterra两种群竞争方程来研究一对共感染的种之间不同的竞争和促进的混合在宿主内的动力学后果。然后，我们考虑这些动态对联合感染的毒力(对宿主的损害)以及随后寄生虫开发策略的演变的影响。我们发现，虽然单向易化带来了一些增加的毒力风险，但互惠易化带来了宿主内部动态的定性明显的不稳定，并带来了严重疾病的最大风险。
Host individuals are often infected with more than one parasite species (parasites defined broadly, to include viruses and bacteria). Yet, research in infection biology is dominated by studies on single-parasite infections. A focus on single-parasite infections is justified if the interactions among parasites are additive, however increasing evidence points to non-additive interactions being the norm. Here we review this evidence and theoretically explore the implications of non-additive interactions between co-infecting parasites. We use classic Lotka-Volterra two-species competition equations to investigate the within-host dynamical consequences of various mixes of competition and facilitation between a pair of co-infecting species. We then consider the implications of these dynamics for the virulence (damage to host) of co-infections and consequent evolution of parasite strategies of exploitation. We find that whereas one-way facilitation poses some increased virulence risk, reciprocal facilitation presents a qualitatively distinct destabilization of within-host dynamics and the greatest risk of severe disease.