奶牛子宫菌群在大肠杆菌感染中作用机制研究

Endometritis causes huge economic losses in dairy industry; therefore, clarifying the pathogenesis is very important for prevention and treatment of cow endometritis. We and others have found that uterine microecology plays crucial roles in the occurrence of cow endometritis, however, its mechanism is still unclear. As E. coli is one of the main pathogenic bacteria, in this project, model of E. coli infection will be used to compare microbial community structure, component of genome, gene expression, metabolites of uterus and microbes and metabolism pathway in uterus of cows during different stage of infection based on technologies of metagenome, metatranscriptome and metabolome. To probe relationship between structure and function of microbial community and metabolic phenotypes, then screen the early biomarkers of E.coli infection and reveal the crucial bacterial in uterus involved in preventing E.coli infection. Finally, In vitro culture technology will be used to study the function of the crucial bacterial during E.coli infection. It is the first time to combine Multi-omics technologies to fully clarify the mechanism of cow uterus microflora in E. coli infection in terms of structure, gene expression and metabolism of microbial community. The results will not only be helpful for fully understanding structure and function of microbial community in cow reproductive tracts, but also provide reference for developing new technology for diagnosis and treatment of cow endometritis.

子宫内膜炎给奶牛业造成巨大经济损失，阐明其发病机制对于该病的防治具有重要意义。我们和他人研究发现，子宫菌群对奶牛子宫内膜炎的发生起至关重要作用，但其作用机制尚不清楚。基于大肠杆菌是奶牛子宫内膜炎的一种主要致病菌，本项目拟利用大肠杆菌感染模型，综合宏基因组学、宏转录组学和代谢组学技术，比较研究大肠杆菌感染子宫不同阶段菌群结构、基因组成份及基因表达和子宫、细菌的共代谢产物和代谢通路，探索菌群结构、功能与子宫代谢表型的关系，发现子宫感染大肠杆菌早期生物标记，揭示参与子宫抵抗大肠杆菌感染的关键细菌，利用体外培养技术研究其在大肠杆菌感染子宫内膜细胞过程中的生物学作用。该项目首次串联多组学技术，从子宫菌群结构、基因表达和代谢角度全面解析奶牛子宫菌群在大肠杆菌感染过程中的作用机制，研究结果不仅有助于全面认识奶牛生殖道菌群的结构和功能，而且也为开发奶牛子宫内膜炎的新型诊断和治疗技术提供参考。

子宫内膜炎给奶牛业造成巨大经济损失，阐明其发病机制对于该病的防治具有重要意义。研究发现，子宫菌群对奶牛子宫内膜炎的发生起至关重要作用，但其作用机制尚不清楚。为了阐明子宫菌群对奶牛子宫内膜炎发生的作用机制，本项目基于大肠杆菌是奶牛子宫内膜炎的一种主要致病菌，利用大肠杆菌感染模型，综合16S rRNA测序、宏基因组和宏转录组技术比较研究奶牛子宫感染大肠杆菌24 h和48 h后子宫菌群结构，并通过功能富集和通路富集，明确大肠杆菌感染奶牛子宫菌群的功能，揭示奶牛子宫菌群在大肠杆菌感染过程中的作用机制；并且项目组利用代谢组测序研究大肠杆菌感染后子宫代谢产物和代谢通路，寻找子宫感染大肠杆菌早期生物标记。结果表明，大肠杆菌感染后与对照组相比具有31个显著差异代谢物，可作为子宫感染大肠杆菌早期生物标记，并富集多种代谢通路。此外，项目组筛选出了子宫内应对大肠杆菌感染的关键细菌（约氏乳杆菌、唾液乳杆菌、魏斯氏乳杆菌）。体外研究发现，三株乳酸菌均显著抑制病原菌的生长，并且能够抑制大肠杆菌诱导的奶牛子宫内膜上皮细胞炎症，而约氏乳杆菌效果最佳。研究结果不仅有助于全面认识奶牛生殖道菌群的结构和功能，而且也为开发奶牛子宫内膜炎的新型诊断和治疗技术提供参考。