不同大菱鲆(Scophthalmus maximus)个体肠道菌群结构差异研究

Different Taxonomic Distribution of Gastrointestinal Tract Microbiome of Turbot(Scophthalmus maximus) Individuals

目的:肠道微生物能够帮助宿主完成多种生理生化功能,对宿主的健康生长也起到非常重要的作用。大菱鲆(Scophthalmus maximus)是我国北方最重要的海水养殖品种之一。然而,细菌性疾病的频发造成大规模的鱼类死亡。此外,许多大菱鲆致病菌也被证实是人类潜在的致病菌。因此鉴定成年养殖大菱鲆肠道中所包含的核心菌群,并筛选可能与大菱鲆或人类健康密切相关的细菌尤为重要。方法:构建三个大菱鲆个体肠道16S rRNA文库,利用限制性片段长度多态性分析(RFLP)及生物信息学技术研究三个大菱鲆个体肠道菌群结构及多样性。结果:共得到758个阳性克隆,16个OTU类型。分类分析显示,变形菌门在大菱鲆肠道中占优势地位。进一步将细菌按属来分类显示,弧菌属所占的比例最高,约为95.3%。韦恩图显示大菱鲆三个个体共有的OTU类型数量为3,分别占三个大菱鲆个体肠道文库中阳性克隆总数的94.9%、96.7%以及93.5%。分类结果显示它们分别属于条件致病菌哈氏弧菌、副溶血弧菌和创伤弧菌。结论:大菱鲆的核心肠道菌群为弧菌属,它的主要成员哈氏弧菌、副溶血弧菌和创伤弧菌对大菱鲆及人类的健康起到关键的作用。在水产养殖过程中,通过监控这些弧菌种类的浓度变化能够及时对养殖环境进行评价,并及时调整温度、水质等因素,这为预防大菱鲆细菌性疾病,保证人类健康提供重要的理论依据。

Objective： Microbial community of gastrointestinal tract plays an important role in host physiology and health. Turbot （Scophthalmus maximus） is one of the most important farmed species in northern China. However, bacterial diseases have become increasingly prominent which lead to considerable mortality. Moreover, many pathogenic bacteria of turbot were also identified as potential human pathogens. Therefore, it is important to identify the core intestinal microbiota in farmed adult turbot （Scophthalmus maximus）, and the bacteria which may be associated with turbot or human health. Methods： Restriction fragment length polymorphism （RFLP） and bioinformatics were applied to investigate the bacterial composition and diversity of gastrointestinal tract in tb_ree individuals. Results： A total of 758 positive clones and 16 OTUs were obtained in this study. Taxonomic analysis indicated that Proteobacteria were dominated in the turbot gastrointestinal microbiome. At the genus level, Vibrio was the most dominated genus, accounting for 95.3% of all positive clones. Venn diagram showed that the number of OTUs shared between three turbot gastrointestinal libraries was 3, i.e., 94.9%, 96.7% and 93.5% of the positive clones were present in the three turbot gastrointestinal libraries, respectively. Taxonomy showed that the shared OTUs belonged to V. harveyi, V. Parahaemolyticus and V. vulrdficus. Conclusion： The core intestinal microbiota of fanned adult turbot was Vibrio. Within Vibrio, the three main species, V. harveyi, V. Parahaemolyticus and V. vulnificus were recognized as potential pathogens which played an important role on turbot and human health. In aquaculture, fanning environment can be evaluated and some other factors, such as temperature, water quality could be also regulated timely by monitoring the change of the concentration of Vibrio species. This study provided an important fbundation for preventing bacterial diseases in turbot and defending human health.