尼罗罗非鱼表皮和鳃黏膜共生菌结构特征及其与鱼体健康状况相关关系

黏膜及其表面的共生菌群是鱼类抵御外界不利环境的第一道屏障。为探索养殖罗非鱼表皮和鳃黏膜共生菌菌群的结构特征是否与其健康状况间存在相关关系,本研究运用高通量测序技术,以无乳链球菌腹腔注射攻毒48 h后存活和濒死尼罗罗非鱼为检测对象,检测攻毒前后罗非鱼表皮和鳃黏膜共生菌群落结构差异。结果显示,健康尼罗罗非鱼表皮和鳃黏膜共生菌均存在优势菌群,主要为特吕珀菌属、硫杆菌属、弓形杆菌属、海单胞菌属和弧菌属。人工感染无乳链球菌后存活尼罗罗非鱼表皮和鳃黏膜共生菌菌群与感染前无显著差异;与存活组相比,濒死尼罗罗非鱼的表皮和鳃黏膜共生菌菌群多样性下降,其中弓形杆菌属、假交替单胞菌属、海单胞菌属、假单胞菌属和弧菌属等含量显著下降,链球菌属含量占总菌群的55.30%±1.24%,表明养殖尼罗罗非鱼表皮和鳃黏膜共生菌群落结构可能与其健康状况相关。

The commensal microbiota structure of Nile tilapia (Oreochromis niloticus) skin and gill surfaces and preliminary study of their implications on tilapia health status

Fish mucosa and their commensal microbiota serve as the first biological bulwark against invading pathogens. The purpose of this study is to study the implications on tilapia health status of the associated commensal microorganisms. Illumina sequencing was used to study the difference between the microbiota of mucosal surfaces from healthy tilapia, live and dying tilapia after Streptococcus agalactiae infection. The results showed that there were several genera dominated on tilapia skin and gill surfaces, i.e., Truepera, Thiobacillus, Arcobacter, Marinomonas, and Vibrio. There was no significant difference between the skin and gill microbiota of the live tilapia after Streptococcus agalactiae infection and those of the initial tilapia sample. A decreased bacterial diversity was shown in the skin and gill microbiota of the dying tilapia after the pathogen infection, and the genera of Arcobacter, Pseudoalteromonas, Marinomonas, Pseudomonas and Vibrio were decreased, while the genus of Streptococcus dominated in the skin and gill microbiota of the dying tilapia after the pathogen infection, with the relative abundance of 55.30%±1.24%. The results suggested that commensal microbiota of tilapia skin and gill surface could be related to fish health.