Kurze Christoph, Mayack Christopher, Hirche Frank, Stangl Gabriele I, Le Conte Yves, Kryger Per, Moritz Robin F A
Institute for Biology, Martin-Luther-Universität Halle-Wittenberg, 06099, Halle (Saale), Germany.
Institute of Agricultural and Nutritional Sciences, Martin-Luther-Universität Halle-Wittenberg, 06120, Halle (Saale), Germany.
Parasitol Res. 2016 Jun;115(6):2381-8. doi: 10.1007/s00436-016-4988-3. Epub 2016 Mar 15.
Host-pathogen coevolution leads to reciprocal adaptations, allowing pathogens to increase host exploitation or hosts to minimise costs of infection. As pathogen resistance is often associated with considerable costs, tolerance may be an evolutionary alternative. Here, we examined the effect of two closely related and highly host dependent intracellular gut pathogens, Nosema apis and Nosema ceranae, on the energetic state in Nosema tolerant and sensitive honeybees facing the infection. We quantified the three major haemolymph carbohydrates fructose, glucose, and trehalose using high-performance liquid chromatography (HPLC) as a measure for host energetic state. Trehalose levels in the haemolymph were negatively associated with N. apis infection intensity and with N. ceranae infection regardless of the infection intensity in sensitive honeybees. Nevertheless, there was no such association in Nosema spp. infected tolerant honeybees. These findings suggest that energy availability in tolerant honeybees was not compromised by the infection. This result obtained at the individual level may also have implications at the colony level where workers in spite of a Nosema infection can still perform as well as healthy bees, maintaining colony efficiency and productivity.
宿主-病原体的共同进化导致相互适应，使病原体能够增加对宿主的利用，或者使宿主将感染成本降至最低。由于病原体抗性通常与相当大的成本相关，耐受性可能是一种进化替代方案。在这里，我们研究了两种密切相关且高度依赖宿主的细胞内肠道病原体——蜜蜂微孢子虫（Nosema apis）和东方蜜蜂微孢子虫（Nosema ceranae），对感染时具有微孢子虫耐受性和敏感性的蜜蜂能量状态的影响。我们使用高效液相色谱法（HPLC）对血淋巴中的三种主要碳水化合物果糖、葡萄糖和海藻糖进行定量，以此作为宿主能量状态的衡量指标。在敏感蜜蜂中，无论东方蜜蜂微孢子虫的感染强度如何，血淋巴中海藻糖水平与蜜蜂微孢子虫感染强度以及与东方蜜蜂微孢子虫感染均呈负相关。然而，在感染微孢子虫的耐受性蜜蜂中不存在这种关联。这些发现表明，耐受性蜜蜂的能量供应并未因感染而受到损害。在个体水平上获得的这一结果，在蜂群水平上可能也有影响，即尽管工蜂感染了微孢子虫，但仍能像健康蜜蜂一样正常工作，维持蜂群的效率和生产力。
