Abstract:

【Objective】 To study the main pathogenic microorganisms of dairy cow mastitis and the distribution of microbiota in milk.【Method】 The cows in the two farms of CJ and HZS were examined for mastitis.After visual and tactile examination of the udder and milk of the cows, 3 milk samples were randomly collected from the dairy cows diagnosed with clinical mastitis in the two farms each, and then 1 milk sample was collected from non-clinical dairy cows.Through PCR amplification and high-throughput sequencing of the 16S rRNA gene V3-V4 regions of bacteria in milk samples of mastitis dairy cows and non-clinical dairy cows, the diversity of microbial communities in clinical dairy milk samples and non-clinical dairy milk samples were analyzed and the differences were compared between the two.【Result】 The results showed that from the 6 clinical mastitis samples, a total of 25 phyla, 47 classes, 82 orders, 174 families, and 349 genera were obtained; from 2 non-clinical dairy cow milk samples, a total of 23 phyla, 38 classes, 61 Orders, 125 families, 212 genera were obtained.In clinical mastitis samples, the dominant bacterial groups were Proteobacteria, Tenericutes, Firmicutes, Bacteroidetes, Actinobacteria; In non-clinical dairy milk samples, the dominant flora were Proteobacteria, followed by Firmicutes and Bacteroidetes.At the genus level, compared with mastitis samples, non-clinical dairy milk samples had fewer dominant bacterial groups, and only streptococcus was detected in HZS mastitis samples and Mycoplasma was detected in CJ mastitis samples.【Conclusion】 After cows suffer from mastitis, the abundance of the microbial flora is significantly increased, and the diversity changes significantly, indicating that the milk cows suffering from mastitis will cause the milk cow's milk flora to be imbalanced, and the changes in the structure and abundance of the milk flora are closely related to the occurrence of mastitis.

Key words: cow; mastitis; microbial diversity

摘要：

【目的】研究奶牛乳房炎主要病原微生物及乳汁中微生物群系分布。【方法】对CJ和HZS 2个牛场的奶牛进行乳房炎检查,视觉和触觉等临床检查奶牛乳房及乳汁后,将2个场中确诊为临床乳房炎的奶牛随机采集乳汁样本各3份,并将非临床型奶牛的乳汁样本随机采集各1份,通过对乳房炎奶牛和非临床型奶牛乳样中细菌的16S rRNA基因V3-V4区的PCR扩增和高通量测序,分析临床奶牛乳汁样本和非临床型奶牛乳汁样本中微生物群落的多样性,并比较二者之间的差异性。【结果】6个临床乳房炎样本共获得25个门,47个纲,82个目,174个科,349个属;2个非临床型奶牛乳汁样本共获得23个门,38个纲,61个目,125个科,212个属。在临床乳房炎样本中,优势菌群分别是变形菌门(Proteobacteria)、无壁菌门(Tenericutes)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria);在非临床型样本中,优势菌群是变形菌门(Proteobacteria),其次是厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)。在属水平上,非临床型样本与乳房炎样本相比,检测到的优势菌群较少,且仅在HZS场乳房炎样本中检测到链球菌,CJ场乳房炎样本中检测到支原体。【结论】奶牛患乳房炎后菌群丰度明显升高,多样性变化显著;奶牛患乳房炎后会引起奶牛乳汁菌群失调,乳汁菌群结构分布和丰度变化与乳房炎的发生具有密切的联系。

关键词: 奶牛, 乳房炎, 微生物多样性