Climate change is altering light regimes in lakes, which should impact disease outbreaks, since sunlight can harm aquatic pathogens. However, some bacterial endospores are resistant to damage from light, even surviving exposure to UV-C. We examined the sensitivity of Pasteuria ramosa endospores, an aquatic parasite infecting Daphnia zooplankton, to biologically relevant wavelengths of light. Laboratory exposure to increasing intensities of UV-B, UV-A, and visible light significantly decreased P. ramosa infectivity, though there was no effect of spore exposure on parasitic castration of infected hosts. P. ramosa is more sensitive than its Daphnia host to damage by longer wavelength UV-A and visible light; this may enable Daphnia to seek an optimal light environment in the water column, where both UV-B damage and parasitism are minimal. Studies of pathogen light sensitivity help us to uncover factors controlling epidemics in lakes, which is especially important given that water transparency is decreasing in many lakes.

中文翻译：

---

光照降低了水蚤寄生虫巴氏巴斯德氏菌的传染性

气候变化正在改变湖泊的光照状态，这将影响疾病的爆发，因为阳光会损害水生病原体。但是，某些细菌内生孢子即使暴露在紫外线下也能抵抗光的伤害。我们检查了巴斯德氏菌内生孢子（一种感染水蚤浮游生物的水生寄生虫）对生物相关波长的光的敏感性。实验室暴露于不断增加的UV-B，UV-A和可见光强度下，虽然孢子暴露对感染宿主的寄生去势没有影响，但可显着降低ramosa P. ramosa的感染力。P. ramosa比水蚤更敏感较长波长的UV-A和可见光会损坏主机；这可以使水蚤能够在水柱中寻找最佳的光照环境，使UV-B损害和寄生虫的发生率最小。对病原体光敏感度的研究有助于我们发现控制湖泊中流行病的因素，鉴于许多湖泊中水的透明度正在下降，这一点尤其重要。