Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, Minnesota, 55108, USA.
Agronomy Department, University of Florida, Gainesville, Florida, 32611, USA.
Ecology. 2020 Nov;101(11):e03155. doi: 10.1002/ecy.3155. Epub 2020 Sep 2.
Interactions among co-infecting pathogens are common across host taxa and can affect infectious disease dynamics. Host nutrition can mediate these among-pathogen interactions, altering the establishment and growth of pathogens within hosts. It is unclear, however, how nutrition-mediated among-pathogen interactions affect transmission and the spread of disease through populations. We manipulated the nitrogen (N) and phosphorus (P) supplies to oat plants in growth chambers and evaluated interactions between two aphid-vectored Barley and Cereal Yellow Dwarf Viruses: PAV and RPV. We quantified the effect of each virus on the other's establishment, within-plant density, and transmission. Co-inoculation significantly increased PAV density when N and P supplies were low and tended to increase RPV density when N supply was high. Co-infection increased PAV transmission when N and P supplies were low and tended to increase RPV transmission when N supply was high. Despite the parallels between the effects of among-pathogen interactions on density and transmission, changes in virus density only partially explained changes in transmission, suggesting that virus density-independent processes contribute to transmission. A mathematical model describing the spread of two viruses through a plant population, parameterized with empirically derived transmission values, demonstrated that nutrition-mediated among-pathogen interactions could affect disease spread. Interactions that altered transmission through virus density-independent processes determined overall disease dynamics. Our work suggests that host nutrition alters disease spread through among-pathogen interactions that modify transmission.
共感染病原体之间的相互作用在宿主分类群中很常见，并且会影响传染病的动态。宿主营养可以调节这些病原体之间的相互作用，改变病原体在宿主中的定植和生长。然而，尚不清楚营养介导的病原体间相互作用如何影响通过种群传播和疾病的传播。我们在生长室中操纵燕麦植物的氮（N）和磷（P）供应，并评估了两种蚜虫传播的大麦和谷物黄矮病毒（PAV 和 RPV）之间的相互作用：PAV 和 RPV。我们量化了每种病毒对另一种病毒的建立、植物内密度和传播的影响。当 N 和 P 供应低时，共同接种显着增加了 PAV 的密度，并且当 N 供应高时，倾向于增加 RPV 的密度。当 N 和 P 供应低时，共同感染会增加 PAV 的传播，而当 N 供应高时，会增加 RPV 的传播。尽管病原体间相互作用对密度和传播的影响存在相似之处，但病毒密度的变化仅部分解释了传播的变化，这表明病毒密度无关的过程有助于传播。一个描述两种病毒通过植物种群传播的数学模型，使用经验得出的传播值进行参数化，表明营养介导的病原体间相互作用会影响疾病的传播。通过病毒密度无关的过程改变传播的相互作用决定了整体疾病动态。我们的工作表明，宿主营养通过改变通过病毒密度无关的过程影响传播的病原体间相互作用来改变疾病的传播。
