Pathogens that use multiple host species are an increasing public health issue due to their complex transmission, which makes them difficult to mitigate. Here, we explore the possibility of using networks of ecological interactions among potential host species to identify the particular disease-source species to target to break down transmission of such pathogens. We fit a mathematical model on prevalence data of Mycobacterium ulcerans in western Africa and we show that removing the most abundant taxa for this category of pathogen is not an optimal strategy to decrease the transmission of the mycobacterium within aquatic ecosystems. On the contrary, we reveal that the removal of some taxa, especially Oligochaeta worms, can clearly reduce rates of pathogen transmission and should be considered as a keystone organism for its transmission because it leads to a substantial reduction in pathogen prevalence regardless of the network topology. Besides its potential application for the understanding of M. ulcerans ecology, we discuss about how networks of species interactions can modulate transmission of multi-host pathogens.

中文翻译：

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识别多宿主病原体的致命弱点：以溃疡分枝杆菌传播为例的关键“宿主”物种概念

由于传播复杂，使用多种宿主物种的病原体是一个日益严重的公共卫生问题，这使得它们难以缓解。在这里，我们探索了使用潜在宿主物种之间的生态相互作用网络来识别特定疾病源物种以分解此类病原体传播的可能性。我们拟合了西非溃疡分枝杆菌流行数据的数学模型，我们表明，去除这类病原体最丰富的分类群并不是减少分枝杆菌在水生生态系统中传播的最佳策略。相反，我们发现去除一些分类群，尤其是寡毛虫，可以明显降低病原体传播率，应被视为其传播的关键生物，因为无论网络拓扑如何，它都会导致病原体流行率大幅降低。除了其在理解溃疡分枝杆菌生态学方面的潜在应用外，我们还讨论了物种相互作用网络如何调节多宿主病原体的传播。