Genetic and functional analysis of the bovine uterine microbiota. Part I: Metritis versus healthy cows
Genetic and functional analysis of the bovine uterine microbiota. Part I: Metritis versus healthy cows
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DOI：
10.3168/jds.2016-12058
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发表时间：
2017-05-01
影响因子：
3.5
通讯作者：
Bicalho, R. C.
中科院分区：
文献类型：
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作者：
Bicalho, M. L. S.;Machado, V. S.;Bicalho, R. C.
子宫炎是一种子宫疾病，影响10%至30%的所有泌乳奶牛，并对生殖性能，产奶量和存活率产生不利影响。关于细菌基因的特性和丰度的数据，如毒力，抗生素耐药性和应激反应，可以使以前未知的代理人，在子宫炎的发病机制中发挥作用的鉴定。此外，这些知识可以导致改进治疗或预防方法的发展。因此，本研究的目的是表征子宫微生物种群，并首次区分子宫炎奶牛与健康奶牛的微生物功能多样性。此外，我们旨在确定微生物基因与产后子宫健康之间的关系。子宫拭子收集24头奶牛在3至12天的牛奶，12头奶牛被诊断为子宫炎，其他12个是健康的。子宫炎定义为水样、红色或褐色的子宫分泌物，有恶臭，直肠温度高于39.5 ℃。具有透明和粘性子宫分泌物、无恶臭或粘液脓性的奶牛被归类为健康。来自子宫拭子样品的微生物宏基因组DNA在Illumina MiSeq平台（Illumina Inc.，加利福尼亚州圣地亚哥）。MG-RAST服务器（使用子系统技术的宏基因组快速注释; http：//metagenomics.anl.gov/）和STAMP软件（http：//kiwi.cs.daLca/Software/STAM.P）用于检测子宫炎和健康奶牛的子宫微生物宏基因组之间的分类学和功能特征丰度的统计学显著差异。我们的研究结果表明，增加了丰富的梭杆菌和拟杆菌在子宫炎的奶牛，证实了潜在的作用，这2个类群的发病机制子宫炎。MG-RAST分析揭示了子宫微生物群中跨细胞质膜和VI型细菌分泌系统的蛋白质转运基因的显著更高丰度。此外，编码对酸应激的抗性的基因是子宫炎微生物群独有的，这表明微生物对酸应激的抗性对于受感染子宫中的微生物存活是重要的。另一方面，编码粘附分子、细菌素和抗菌肽的基因与健康奶牛的子宫微生物群显著相关，对大肠杆菌素E2的耐受性也是如此。
Metritis is a uterine disease that affects 10 to 30% of all lactating dairy cows and has detrimental effects on reproductive performance, milk production, and survival. Data regarding the identity and abundance of bacterial genes governing traits such as virulence, antibiotic resistance, and stress responses could enable identification of previously unknown agents that play a role in metritis pathogenesis. Moreover, such knowledge could lead to the development of improved treatments or preventive methods. Therefore, the objectives of this study were to characterize the uterine microbial population and to differentiate, for the first time, the microbial functional diversity in cows with metritis versus healthy cows. In addition, we aimed to identify relationships between microbial genes and postpartum uterine health. Uterine swabs were collected from 24 cows within 3 to 12 d in milk; 12 cows were diagnosed with metritis and the other 12 were healthy. Metritis was defined as a watery, reddish or brownish uterine discharge having a fetid smell, and rectal temperature greater than 39.5 degrees C. Cows with a clear and viscous uterine discharge, not fetid or mucopurulent, were classified as healthy. Microbial metagenomic DNA from uterine swab samples was subjected to whole-genome shotgun sequencing on the Illumina MiSeq platform (Illumina Inc., San Diego, CA). The MG-RAST server (metagenomic rapid annotations using subsystems technology; http://metagenomics.anl.gov/) and STAMP software (http://kiwi.cs.daLca/Software/STAM.P) were used to detect statistically significant differences in the abundance of taxonomic and functional features between the uterine microbial metagenomes of metritic and healthy cows. Our results showed an increased abundance of Fusobacteria and Bacteroidetes in metritic cows, confirming the potential role of those 2 taxa in the pathogenesis of metritis. The MG-RAST analysis revealed a significantly higher abundance of genes for protein transport across the cytoplasmic membrane and type VI bacterial secretion systems in the metritic microbiota. Additionally, genes coding for resistance to acid stress were exclusive to the metritis microbiota, suggesting that microbial resistance to acid stress is important for microbial survival in the infected uterus. On the other hand, genes coding for adhesion molecules, bacteriocins, and antibacterial peptides were significantly associated with the uterine microbiota of healthy cows, as was tolerance to colicin E2.