背景:牛乳腺炎是影响奶牛的最重要的经济疾病之一。床上用品的选择已被确定为导致乳腺炎发展的重要风险因素。然而,很少有报告检查了常用床上用品的可培养和不可培养的微生物组成,即,微生物组。考虑到大多数环境中不可培养微生物的普遍存在,这些信息可能是了解床上用品微生物组是否以及如何成为乳腺炎危险因素的重要一步.因此,我们的目标是表征垫料微生物组的微生物组组成和多样性,使用前和使用后。
方法:我们从美国44个奶牛场收集了88个床上用品样本。未使用的(来自储存堆)和已使用的(来自摊位)床上用品从四种类型的床上用品中收集:新沙子(NSA),回收粪肥固体(RMS),有机非粪肥(ON)和再生砂(RSA)。使用V3-V4区的16SrRNA测序分析样品。
结果:几种微生物类群的总体组成和计数在垫层类型之间有所不同,与变形杆菌,放线菌,拟杆菌和Firmicutes在所有类型中占主导地位。用过的床上用品含有与未使用的床上用品明显不同的微生物组成,但是这种差异的大小因垫层类型而异,RMS垫层表现出最小的差异。此外,在潜在的乳腺炎病原体(细菌属)的16SrRNA序列计数与相应的垫层细菌培养数据之间观察到正相关。
结论:我们的结果加强了床上用品作为乳腺炎病原体的潜在来源的作用。奶牛在使用过程中发生的所有床上用品类型的微生物组的一致变化值得进一步研究,以了解这种变化是否会促进病原体定植和/或持久性。或者它是否可以不同地影响乳房健康结果。通过在研究设计中加入微生物组成分,可以加强对床上用品和乳房健康的未来研究。
BACKGROUND: Bovine mastitis is one of the most economically important diseases affecting dairy cows. The choice of bedding material has been identified as an important risk factor contributing to the development of mastitis. However, few reports examine both the culturable and nonculturable microbial composition of commonly used bedding materials, i.e., the microbiome. Given the prevalence of nonculturable microbes in most environments, this information could be an important step to understanding whether and how the bedding microbiome acts as a risk factor for mastitis. Therefore, our objective was to characterize the microbiome composition and diversity of bedding material microbiomes, before and after use.
METHODS: We collected 88 bedding samples from 44 dairy farms in the U.S. Unused (from storage pile) and used (out of stalls) bedding materials were collected from four bedding types: new sand (NSA), recycled manure solids (RMS), organic non-manure (ON) and recycled sand (RSA). Samples were analyzed using 16S rRNA sequencing of the V3-V4 region.
RESULTS: The overall composition as well as the counts of several microbial taxa differed between bedding types, with Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes dominating across all types. Used bedding contained a significantly different microbial composition than unused bedding, but the magnitude of this difference varied by bedding type, with RMS bedding exhibiting the smallest difference. In addition, positive correlations were observed between 16S rRNA sequence counts of potential mastitis pathogens (bacterial genera) and corresponding bedding bacterial culture data.
CONCLUSIONS: Our results strengthen the role of bedding as a potential source of mastitis pathogens. The consistent shift in the microbiome of all bedding types that occurred during use by dairy cows deserves further investigation to understand whether this shift promotes pathogen colonization and/or persistence, or whether it can differentially impact udder health outcomes. Future studies of bedding and udder health may be strengthened by including a microbiome component to the study design.