论文部分内容阅读
凡纳滨对虾养殖过程中,早期阶段是病害易感阶段,而消化道菌群结构与对虾健康关系密切。因此,探讨幼虾的消化道菌群尤其是弧菌类细菌与对虾发病的关系对病害有效防治具有重要意义。本实验采用Illumina测序研究了凡纳滨对虾健康和患病幼虾的消化道细菌群落结构,并基于纯培养和16S r DNA,rec A和pyr H基因序列比对,分析了幼虾消化道中弧菌的主要种类组成。结果发现,健康幼虾消化道中α-变形菌纲和厚壁菌门丰度较高,而患病幼虾中γ-变形菌纲、拟杆菌门、放线菌门和β-变形菌纲较高,其中放线菌门丰度差异显著。基于科水平的响应比分析,发现患病幼虾消化道中动性球菌科和噬菌弧菌科的丰度显著降低,而弧菌科的丰度显著升高。相似度分析发现,驱动群落变异的OTU主要来源于弧菌属、海洋杆状菌属、冷杆菌属、假交替单胞菌属以及未分类至属的红杆菌科和微杆菌科。健康幼虾消化道弧菌组成以锡那罗亚州弧菌为主,而患病幼虾消化道弧菌组成以坎氏弧菌为主。尽管健康和患病幼虾消化道内细菌群落结构整体差异不显著,但一些重要类群丰度变化显著,其特征与已知的生态功能一致。
Litopenaeus vannamei breeding process, the early stages of disease susceptibility stage, and the structure of digestive tract flora and shrimp health are closely related. Therefore, to explore juvenile gut flora, especially Vibrio bacteria and shrimp pathogenesis of effective prevention and treatment of disease is of great significance. In this study, Illumina sequencing was used to study the bacterial community structure of digestive tract in healthy and diseased juvenile Litopenaeus vannamei. Based on the comparison of 16S r DNA, rec A and pyr H gene sequences in pure culture, The main types of bacteria composition. The results showed that the healthy juvenile shrimp digestive α-Proteobacteria and thick-walled bacteria higher abundance, and the prevalence of juvenile γ-proteobacteria, Bacteroides, Actinomyces and β-Proteobacteria more High, including Actinomycetes abundance significant difference. Based on the analysis of subjects’ level of response, the abundance of Neisseria gonorrhoeae and Vibrio phageae in the digestive tract of juvenile shrimp was significantly decreased, while the abundance of Vibrio was significantly higher. Similarity analysis revealed that the OTUs that drive community variation mainly came from Vibrio, Marine Bacillus, Corynebacterium, Pseudoalteromonas, and not belonging to the genus Rhizobacteria and Microbacteriaceae. Vibrio gonorrhoeae of juvenile shrimp is mainly composed of Vibrio sinora in Sinaloa, while Vibrio vulnificus of juvenile shrimp is mainly composed of Vibrio vulnificus. Although the overall differences in bacterial community structure in the digestive tract of healthy and diseased shrimp are not significant, the abundance of some important groups varies significantly, with characteristics consistent with known ecological functions.