Xue Shuxia, Xu Wei, Wei Junli, Sun Jinsheng
Tianjin Key Laboratory of Animal and Plant Resistance/College of Life Science, Tianjin Normal University, Tianjin, China; Tianjin Center for Control and Prevention of Aquatic Animal Infectious Disease, Tianjin, China; Louisiana State University, Agricultural Center, United States.
Louisiana State University, Agricultural Center, United States; School of Renewable Natural Resources, Louisiana State University, Baton Rouge, LA, United States.
Vet Microbiol. 2017 May;203:34-39. doi: 10.1016/j.vetmic.2017.01.034. Epub 2017 Feb 3.
Marine cultured fish diseases caused by bacteria in recirculating aquaculture systems (RASs) greatly threaten fish aquaculture. To date, the dynamics of bacterial populations in RAS and their impacts to fish health remain largely unknown. In the present study, the bacterial communities in the water from two different marine RASs were analyzed using pyrosequencing technique. Fish disease syndromes and mortality had been reported from one RAS (RAS-d) while the fish in the other RAS remained healthy (RAS-h). The diversity of bacteria in each RAS and the abundance of each bacterium were identified based on sequencing the V4 hypervariable region of the 16S rRNA gene. A total number of 107,476 effective sequences were obtained from the pyrosequencing results. 640 and 844 operational taxonomic units (OTUs) were identified in RAS-d and RAS-h, respectively. In order level, tags annotation showed that Vibrionales and Flavobacteriales were the predominant strains in RAS-d with a relative abundance 50.5% and 36.5%, respectively. In contrast, the bacterial community in RAS-h contained 35.8% Vibrionales, 17.3% Alteromonadales, 10.7% Rhodobacterales, 7.43% Kordiimonadales, and 6.26% Oceanospirillales. In addition, the Vibrionaceae in the RAS-d represented 6.98% of the population which was significantly higher than that in RAS-h (0.40%). More potential pathogenic bacteria in fish, such as Vibrio harveyi, Vibrio rotiferianus were also found in the bacterial population in RAS-d. The results also showed that the bacteria community in RAS-h was more diverse and balanced than in RAS-d. These findings of this study suggested a potential correlation between fish diseases and environmental bacterial populations.
循环水养殖系统（RAS）中由细菌引起的海水养殖鱼类疾病对鱼类养殖构成了巨大威胁。迄今为止，RAS中细菌种群的动态及其对鱼类健康的影响在很大程度上仍不为人知。在本研究中，利用焦磷酸测序技术分析了两个不同海水RAS系统水中的细菌群落。其中一个RAS系统（RAS-d）曾报告出现鱼类疾病症状和死亡情况，而另一个RAS系统中的鱼类保持健康（RAS-h）。通过对16S rRNA基因的V4高变区进行测序，确定了每个RAS系统中细菌的多样性以及每种细菌的丰度。焦磷酸测序结果共获得107,476条有效序列。在RAS-d和RAS-h中分别鉴定出640个和844个可操作分类单元（OTU）。在目水平上，标签注释显示弧菌目和黄杆菌目是RAS-d中的优势菌株，相对丰度分别为50.5%和36.5%。相比之下，RAS-h中的细菌群落包含35.8%的弧菌目、17.3%的交替单胞菌目、10.7%的红杆菌目、7.43%的科尔迪氏菌目和6.26%的海洋螺菌目。此外，RAS-d中的弧菌科占种群的6.98%，显著高于RAS-h中的比例（0.40%）。在RAS-d的细菌种群中还发现了更多鱼类中的潜在致病细菌，如哈维氏弧菌、轮虫弧菌。结果还表明，RAS-h中的细菌群落比RAS-d中的更加多样和平衡。本研究的这些发现表明鱼类疾病与环境细菌种群之间可能存在关联。
