Abstract:
Bovine mastitis is a widespread infectious disease. In addition to the economic damages associated with reduced milk yield due to mastitis, the problem of food contamination by microorganism metabolites, in particular toxins, is also a concern. Horizontal transfer of microorganisms from animal populations to humans can also be complicated by antibiotic resistance. Therefore, bovine mastitis is relevant to the study of microbiology and veterinary medicine. In this study, we investigated the microbiome of milk samples from healthy cows and cows with different forms of mastitis from individual quarters of the udder of cows during first and second lactation. Total DNA was extracted from milk samples. The V3-V4 regions of the bacterial 16S rRNA genes from each sample were amplified to generate a library via high-throughput sequencing. We revealed significant dominance of several operational taxonomic units (OTUs) corresponding mostly to groups of Staphylococcus aureus, Aerococcus spp., and Streptococcus spp. In addition, we unexpectedly identified Streptococcus thermophilus in samples with high SCC quantities. We found some infectious agents that characterized summer mastitis. We demonstrated that in Central Russia, mastitis is associated with a wide variety of causal organisms. We observed some differences in the diversity of the two investigated farms. However, we did not find any significant difference among healthy, mastitis and subclinical samples according to their SCC status from either farms by principal component analysis. Linear discriminant analysis effect size (LEfSe) confirmed the presence of several indicator genera in farms from Moscow and the Tula Region. These results confirm the complex bacterial etiology of bovine mastitis.
摘要:
牛乳腺炎是一种广泛存在的传染病。除了与乳腺炎导致的产奶量降低相关的经济损失外,微生物代谢物污染食品的问题,特别是毒素,也是一个问题。微生物从动物种群向人类的水平转移也可能因抗生素抗性而变得复杂。因此,牛乳腺炎与微生物学和兽医学的研究有关。在这项研究中,我们调查了第一次和第二次泌乳期间,健康奶牛和奶牛乳房各部分乳腺炎不同形式的奶牛的牛奶样品的微生物组。从奶样品中提取总DNA。通过高通量测序扩增来自每个样品的细菌16SrRNA基因的V3-V4区域以产生文库。我们揭示了几个操作分类单位(OTU)的显着优势,主要对应于金黄色葡萄球菌组,空气球菌属。,和链球菌。此外,我们意外地在SCC含量高的样品中发现了嗜热链球菌。我们发现了一些以夏季乳腺炎为特征的传染性病原体。我们证明了在俄罗斯中部,乳腺炎与多种病原体有关。我们观察到两个被调查农场的多样性存在一些差异。然而,我们没有发现健康之间的任何显着差异,通过主成分分析,根据来自任一农场的SCC状态进行乳腺炎和亚临床样本。线性判别分析效应大小(LEfSe)证实了莫斯科和图拉地区农场中存在几个指示属。这些结果证实了牛乳腺炎的复杂细菌病因。