Faculty of Agricultural and Environmental Sciences, Macdonald Campus, McGill University, Quebec, Canada.
Mastitis Network, Saint-Hyacinthe, Québec, Canada.
mSystems. 2024 Oct 22;9(10):e0036224. doi: 10.1128/msystems.00362-24. Epub 2024 Sep 10.
is a common environmental pathogen associated with clinical mastitis (CM) in dairy cattle. There is an interest in optimizing the udder microbiome to increase the resistance of dairy cattle to CM; however, the details of which members of the healthy udder microbiome may play a role in antagonizing are unknown. In this study, we characterized the bacterial community composition in raw milk collected from quarters of lactating Holstein dairy cows that developed CM during lactation, including milk from both healthy and diseased quarters ( = 1,172). The milk microbiome from infected quarters was compared before, during, and after CM. A combination of 16S rRNA gene amplicon and metagenomic sequencing was used generate data sets with a high level of both depth and breadth. The microbial diversity present in raw milk significantly decreased in quarters experiencing CM, indicating that displaces other members of the microbiome. However, the diversity recovered very rapidly after infection. Two genera, and , and the family Oscillospiraceae were significantly more abundant in healthy quarters with low inflammation. Species of these genera, and , were identified by metagenomics. Thus, these species are of interest for optimizing the microbiome to discourage colonization without triggering inflammation.IMPORTANCEIn this study, we show that outcompetes and displaces several members of the udder microbiome during CM, but that microbial diversity recovers post-infection. In milk from quarters which remained healthy, the community composition was often highly dominated by and without increases in somatic cell count (SCC). Community dominance by these organisms, without inflammation, could indicate that these species might have potential as prophylactic probiotics which could contribute to colonization resistance and prevent future instances of CM.
是一种常见的环境病原体，与奶牛的临床乳腺炎（CM）有关。人们对优化乳房微生物组以提高奶牛对 CM 的抵抗力感兴趣；然而，健康乳房微生物组中的哪些成员可能在拮抗中发挥作用尚不清楚。在这项研究中，我们对处于泌乳期的荷斯坦奶牛的 quarters 中采集的初乳中的细菌群落组成进行了表征，这些奶牛在泌乳期发生了 CM，包括健康和患病 quarters 的牛奶（= 1,172）。感染 quarters 的牛奶微生物组在 CM 发生之前、期间和之后进行了比较。使用 16S rRNA 基因扩增子和宏基因组测序的组合生成了具有深度和广度的数据集。在经历 CM 的 quarters 中，初乳中存在的微生物多样性显着降低，表明 取代了微生物组的其他成员。然而，感染后多样性恢复得非常快。在炎症程度较低的健康 quarters 中，两个属 和 以及 Oscillospiraceae 家族的丰度明显更高。通过宏基因组学鉴定了这些属的物种 和 。因此，这些物种对于优化微生物组以阻止 定植而不引发炎症很有意义。
重要性
在这项研究中，我们表明，在 CM 期间， 会与乳房微生物组的几个成员竞争并取代它们，但感染后微生物多样性会恢复。在保持健康的 quarters 的牛奶中，群落组成通常高度由 和 主导，而体细胞计数（SCC）没有增加。这些生物体没有炎症的群落主导地位可能表明这些物种可能具有作为预防性益生菌的潜力，这可能有助于定植抗性并防止未来发生 CM。
