Temperature-mediated inhibition of a bumblebee parasite by an intestinal symbiont
Temperature-mediated inhibition of a bumblebee parasite by an intestinal symbiont
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肠道共生体对大黄蜂寄生虫的温度介导抑制
DOI：
10.1098/rspb.2018.2041
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
McFrederick, Quinn S.
中科院分区：
文献类型：
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作者：
Palmer-Young, Evan C.;Raffel, Thomas R.;McFrederick, Quinn S.
生物体之间的竞争通常由环境因素介导，包括温度。在动物肠道中，非致病性共生体在物理和化学上与病原体竞争，从而导致宿主感染。我们使用代谢理论为基础的模型来表征温度的细菌共生体和共同发生的锥虫寄生虫的熊蜂，调节体温在飞行和孵化过程中的差异反应。我们假设细菌共生体对寄生虫的抑制作用会随着温度的升高而增加，因为共生体比寄生虫具有更高的最佳生长温度。我们发现，温度升高超过在大黄蜂殖民地测量的范围将有利于共生体而不是寄生虫。正如我们的假设所预测的那样，共生体降低了寄生虫的最佳生长温度，无论是在直接竞争中，还是当寄生虫暴露于共生体培养基中时。共生体的抑制作用随温度的升高而增加，反映了共生体的加速生长和产酸。我们的研究结果表明，高温，无论是由于主机吸热或环境因素，可以增强共生体对寄生虫的抑制作用。对微生物群的温度调节操作可能是发烧和热诱导的动物感染减少的一种解释，其后果是医学和保护关注的疾病。
Competition between organisms is often mediated by environmental factors, including temperature. In animal intestines, nonpathogenic symbionts compete physically and chemically against pathogens, with consequences for host infection. We used metabolic theory-based models to characterize differential responses to temperature of a bacterial symbiont and a co-occurring trypanosomatid parasite of bumblebees, which regulate body temperature during flight and incubation. We hypothesized that inhibition of parasites by bacterial symbionts would increase with temperature, due to symbionts having higher optimal growth temperatures than parasites. We found that a temperature increase over the range measured in bumblebee colonies would favour symbionts over parasites. As predicted by our hypothesis, symbionts reduced the optimal growth temperature for parasites, both in direct competition and when parasites were exposed to symbiont spent medium. Inhibitory effects of the symbiont increased with temperature, reflecting accelerated growth and acid production by symbionts. Our results indicate that high temperatures, whether due to host endothermy or environmental factors, can enhance the inhibitory effects of symbionts on parasites. Temperature-modulated manipulation of microbiota could be one explanation for fever- and heat-induced reductions of infection in animals, with consequences for diseases of medical and conservation concern.