Bienentreu Joe-Felix, Schock Danna M, Greer Amy L, Lesbarrères David
Department of Biology, Laurentian University, Sudbury, ON, Canada.
Sciences and Environmental Technology, Keyano College, Fort McMurray, AB, Canada.
Front Vet Sci. 2022 Feb 9;9:755426. doi: 10.3389/fvets.2022.755426. eCollection 2022.
In an era where emerging infectious diseases are a serious threat to biodiversity, epidemiological patterns need to be identified, particularly the complex mechanisms driving the dynamics of multi-host pathogens in natural communities. Many amphibian species have faced unprecedented population declines associated with diseases. Yet, specific processes shaping host-pathogen relationships within and among communities for amphibian pathogens such as ranaviruses (RV) remain poorly understood. To address this gap, we conducted a comprehensive study of RV in low-diversity amphibian communities in north-western Canada to assess the effects of biotic factors (species identity, species richness, abundance) and abiotic factors (conductivity, pH) on the pathogen prevalence and viral loads. Across 2 years and 18 sites, with communities of up to three hosts (wood frog, ; boreal chorus frog, ; Canadian toad, ), we observed that RV prevalence nearly doubled with each additional species in a community, suggesting an amplification effect in aquatic, as well as terrestrial life-history stages. Infection intensity among infected wood frogs and boreal chorus frogs also significantly increased with an increase in species richness. Interestingly, we did not observe any effects of host abundance or abiotic factors, highlighting the importance of including host identity and species richness when investigating multi-host pathogens. Ultimately, only such a comprehensive approach can improve our understanding of complex and often highly context-dependent host-pathogen interactions.
在一个新兴传染病对生物多样性构成严重威胁的时代，需要识别流行病学模式，尤其是驱动自然群落中多宿主病原体动态变化的复杂机制。许多两栖动物物种面临着与疾病相关的前所未有的种群数量下降。然而，对于蛙病毒（RV）等两栖动物病原体而言，在群落内部和群落之间塑造宿主-病原体关系的具体过程仍知之甚少。为了填补这一空白，我们对加拿大西北部低多样性两栖动物群落中的RV进行了一项全面研究，以评估生物因素（物种身份、物种丰富度、丰度）和非生物因素（电导率、pH值）对病原体患病率和病毒载量的影响。在两年时间里，我们在18个地点进行了研究，这些地点的群落中最多有三种宿主（林蛙、北方合唱蛙、加拿大蟾蜍），我们观察到，群落中每增加一个物种，RV患病率几乎就会翻倍，这表明在水生以及陆地生活史阶段都存在放大效应。感染的林蛙和北方合唱蛙的感染强度也随着物种丰富度的增加而显著增加。有趣的是，我们没有观察到宿主丰度或非生物因素的任何影响，这突出了在调查多宿主病原体时纳入宿主身份和物种丰富度的重要性。最终，只有这样一种全面的方法才能增进我们对复杂且往往高度依赖具体情境的宿主-病原体相互作用的理解。
