基于16S rDNA扩增子测序技术揭示真胃左方变位对奶牛粪便微生物的影响

Revealing the impact of left displacement of the abomasum on fecal microbes of dairy cows by 16S rDNA amplicon sequencing technology

摘要:

[目的] 本试验旨在测定产后健康奶牛和罹患真胃左方变位（left displacement of the abomasum，LDA）奶牛粪便中微生物菌群的变化，以期探讨LDA发生与菌群的关联性，评估其对机体代谢的潜在影响。[方法] 采用16S rDNA高通量测序技术，测定10头健康奶牛（Health）、10头真胃左方变位奶牛（LDA）粪便中微生物16S rDNA V3-V4区序列，并对菌群群落结构和多样性进行比较，分析其与LDA发生的相关性。[结果] 多样性分析表明，Health组与LDA组奶牛的粪便中微生物多样性和群落组成存在较大的差异，其中LDA奶牛粪便微生物具有较高的物种丰度和种群差异性。对门、科、属3个分类水平上最大丰度排名前10的物种进行分析发现，LDA奶牛疣微菌门、蓝菌门、变形菌门、梭杆菌门、拟杆菌科、p-2534-18B5菌科、艰难杆菌科、梭杆菌科、螺旋菌属、5-7N15菌属和梭杆菌属的丰度显著升高（P<；0.05），而螺旋体门、TM7菌门、瘤胃球菌科、理研菌科、密螺旋体属的丰度显著下降（P<；0.05）。功能预测分析表明，LDA奶牛碳水化合物代谢和脂质代谢通路相关功能基因显著上调，而遗传信息处理相关功能基因显著下调。[结论] 本试验研究了健康奶牛和LDA奶牛粪便微生物的变化，为LDA的致病机理、早期诊断提供了理论依据与研究基础。

Abstract:

[Objective] Our study aims to measure the changes of microbial flora in feces of healthy postpartum cows and cows suffering from left displacement of the abomasum (LDA), so as to explore the relevance between LDA occurrence and the flora, and assess its potential impact on body metabolism. [Methods] We used 16S rDNA High-Throughput Sequencing technology to determine the 16S rDNA V3-V4 region sequence of microorganisms in the feces of 10 healthy cows and 10 cows with LDA. [Results] The diversity analysis indicated that there were significant differences in microbial diversity and community composition between healthy group and LDA group, and the fecal microbes of the LDA cows had higher species abundance and population differences. The analysis of the top 10 species with the largest abundance at the level of phyla, family, and genus showed that the abundances of Verrucomicrobia, Cyanobacteria, Proteobacteria, Fusobacteria, Bacteroides, p-2534-18B5, Mogibacteriaceae, Fusobacteriaceae, Oscillospira, 5-7N15 and Faecococcus in LDA cows increasedsignificantly (P<0.05), while the abundances of Spirochetes, TM7, Ruminococcaceae, Rikenellaceae and Treponema decreased significantly (P<0.05). Functional prediction analysis showed that the functional genes related to carbohydrate metabolism and lipid metabolism pathway in cows with LDA were greatly up-regulated, while those related to genetic information processing were significantly down regulated. [Conclusion] Our findings confirm that the changes of fecal microorganisms in dairy cows before and after LDA, and provide a foundation for a deeper understanding of the pathogenesis and early diagnosis of LDA.