Amoebic gill disease is a parasitic condition that commonly affects marine farmed Atlantic salmon. The causative agent, Neoparamoeba perurans, induces a marked proliferation of the gill mucosa and focal superficial necrosis upon branchial lesions. The effect that amoebic branchialitis has upon gill associated commensal bacteria is unknown. A 16S rRNA sequencing approach was employed to profile changes in bacterial community composition, within amoebic gill disease (AGD)-affected and non-affected gill tissue. The bacterial diversity of biopsies with and without diseased tissue was significantly lower in the AGD-affected fish compared to uninfected fish. Furthermore, within the AGD-affected tissue, lesions appeared to contain a significantly higher abundance of the Flavobacterium, Tenacibaculum dicentrarchi compared to adjunct unaffected tissues. Quantitative PCR specific to both N. perurans and T. dicentrarchi was used to further examine the co-abundance of these known fish pathogens. A moderate positive correlation between these pathogens was observed. Taken together, the present study sheds new light on the complex interaction between the host, parasite and bacterial communities during AGD progression. The role that T. dicentrarchi may play in this complex relationship requires further investigation.

中文翻译：

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由 Neoparamoeba perurans Challenge 引起的鳃部病变的细菌学分析揭示了受 AGD 影响的大西洋鲑鱼 (Salmo salar L.) 中的共生失调以及与双中心粘带杆菌的关联。


阿米巴鳃病是一种常见影响海水养殖大西洋鲑鱼的寄生虫病。病原体，新帕拉米巴，perurans ，引起鳃粘膜显着增殖和鳃损伤后的局灶性浅表坏死。阿米巴鳃炎对鳃相关共生细菌的影响尚不清楚。采用 16S rRNA 测序方法来分析受阿米巴鳃病 (AGD) 影响和未受影响的鳃组织内细菌群落组成的变化。与未感染的鱼相比，受 AGD 影响的鱼中有或没有患病组织的活组织检查中的细菌多样性显着降低。此外，在受 AGD 影响的组织中，与未受影响的附属组织相比，病变部位似乎含有显着更高丰度的黄杆菌、双中心粘杆菌。使用针对N. perurans和T. dicentrarchi的特异性定量 PCR 来进一步检查这些已知鱼类病原体的共丰度。观察到这些病原体之间存在中度正相关。总而言之，本研究为 AGD 进展过程中宿主、寄生虫和细菌群落之间复杂的相互作用提供了新的线索。 T. dicentrarchi在这种复杂关系中可能发挥的作用需要进一步研究。