Gignoux-Wolfsohn Sarah A, Aronson Felicia M, Vollmer Steven V
Department of Ecology, Evolution, & Natural Resources School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901-8525, USA.
Marine Science Center, Northeastern University, Nahant, MA 01908, USA.
FEMS Microbiol Ecol. 2017 Jul 1;93(7). doi: 10.1093/femsec/fix080.
Increased bacterial diversity on diseased corals can obscure disease etiology and complicate our understanding of pathogenesis. To untangle microbes that may cause white band disease signs from microbes responding to disease, we inoculated healthy Acropora cervicornis corals with an infectious dose from visibly diseased corals. We sampled these dosed corals and healthy controls over time for sequencing of the bacterial 16S region. Endozoicomonas were associated with healthy fragments from 4/10 colonies, dominating microbiomes before dosing and decreasing over time only in corals that displayed disease signs, suggesting a role in disease resistance. We grouped disease-associated bacteria by when they increased in abundance (primary vs secondary) and whether they originated in the dose (colonizers) or the previously healthy corals (responders). We found that all primary responders increased in all dosed corals regardless of final disease state and are therefore unlikely to cause disease signs. In contrast, primary colonizers in the families Pasteurellaceae and Francisellaceae increased solely in dosed corals that ultimately displayed disease signs, and may be infectious foreign bacteria involved in the development of disease signs. Moving away from a static comparison of diseased and healthy bacterial communities, we provide a framework to identify key players in other coral diseases.
患病珊瑚上细菌多样性的增加可能会掩盖疾病病因，并使我们对发病机制的理解变得复杂。为了区分可能导致白带病症状的微生物和对疾病做出反应的微生物，我们用来自明显患病珊瑚的感染剂量接种健康的鹿角珊瑚。我们随着时间对这些接种珊瑚和健康对照进行采样，用于细菌16S区域的测序。内共生菌与10个菌落中4个的健康片段相关，在接种前主导微生物群落，并且仅在出现疾病症状的珊瑚中随时间减少，表明其在抗病中发挥作用。我们根据疾病相关细菌丰度增加的时间（原发性与继发性）以及它们是源自接种物（定植菌）还是先前健康的珊瑚（反应菌）对其进行分组。我们发现，所有原发性反应菌在所有接种珊瑚中均增加，无论最终疾病状态如何，因此不太可能导致疾病症状。相比之下，巴斯德氏菌科和弗朗西斯菌科的原发性定植菌仅在最终出现疾病症状的接种珊瑚中增加，可能是参与疾病症状发展的感染性外来细菌。我们不再对患病和健康细菌群落进行静态比较，而是提供了一个框架来识别其他珊瑚疾病中的关键因素。
