Krediet Cory J, Meyer Julie L, Gimbrone Nicholas, Yanong Roy, Berzins Ilze, Alagely Ali, Castro Herman, Ritchie Kim B, Paul Valerie J, Teplitski Max
Interdisciplinary Ecology Graduate Program, School of Natural Resources and Environment, University of Florida-IFAS, Gainesville, FL, 32610, USA.
Environ Microbiol Rep. 2014 Jun;6(3):287-92. doi: 10.1111/1758-2229.12151. Epub 2014 Mar 25.
Coral reefs are under increasing stress caused by global and local environmental changes, which are thought to increase the susceptibility of corals to opportunistic pathogens. In the absence of an easily culturable model animal, the understanding of the mechanisms of disease progression in corals remains fairly limited. In the present study, we tested the susceptibility of the tropical sea anemone Aiptasia pallida to an opportunistic coral pathogen (Serratia marcescens). A. pallida was susceptible to S. marcescens PDL100 and responded to this opportunistic coral pathogen with darkening of the tissues and retraction of tentacles, followed by complete disintegration of polyp tissues. Histological observations revealed loss of zooxanthellae and structural changes in eosinophilic granular cells in response to pathogen infection. A screen of S. marcescens mutants identified a motility and tetrathionate reductase mutants as defective in virulence in the A. pallida infection model. In co-infections with the wild-type strain, the tetrathionate reductase mutant was less fit within the surface mucopolysaccharide layer of the host coral Acropora palmata.
珊瑚礁正承受着全球和局部环境变化带来的日益增加的压力，这些变化被认为会增加珊瑚对机会性病原体的易感性。由于缺乏易于培养的模式动物，对珊瑚疾病进展机制的了解仍然相当有限。在本研究中，我们测试了热带海葵苍白艾氏海葵对一种机会性珊瑚病原体（粘质沙雷氏菌）的易感性。苍白艾氏海葵对粘质沙雷氏菌PDL100敏感，对这种机会性珊瑚病原体的反应是组织变黑和触手收缩，随后珊瑚虫组织完全解体。组织学观察显示，响应病原体感染，虫黄藻丧失，嗜酸性粒细胞出现结构变化。对粘质沙雷氏菌突变体的筛选确定了一个运动性和连四硫酸盐还原酶突变体在苍白艾氏海葵感染模型中致病性存在缺陷。在与野生型菌株的共感染中，连四硫酸盐还原酶突变体在宿主珊瑚鹿角珊瑚的表面粘多糖层内适应性较差。
