State Key Laboratory of Animal Nutrition and Feeding, International Calf and Heifer Organization, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
State Key Laboratory of Animal Nutrition and Feeding, International Calf and Heifer Organization, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
J Hazard Mater. 2024 Dec 5;480:136005. doi: 10.1016/j.jhazmat.2024.136005. Epub 2024 Oct 1.
Virulence factor genes (VFGs) pose a potential threat to ecological security and animal health, and have attracted increasing attention in the livestock industry. As one of the primary livestock types, dairy cattle may be an important source of VFG transmission. However, the distribution, transmission, and evolution of VFGs in the gastrointestinal tract and surrounding environment of dairy cattle remain unclear. In the present study, a total of 263 samples were collected from cows, calves, colostrum, farm wastewater, and soil. Metagenomics was conducted to analyze changes in the microbiome and VFGs characteristics in these ecological niches. The VFGs of the cows showed distinct differences between the rumen and feces, and were influenced by the region. The dominant VFG hosts was regulated by their microbial structure. Colostrum administration of cows increased VFG abundance in their newborn calf feces sharply and Enterobacteriaceae became the primary host. While diet was the primary driving force for the temporal variation in calf VFGs. For samples of the surrounding environment, water and soil had higher VFG concentrations and were more structurally stable. Moreover, extensive interactions between the mobile genetic elements and VFGs and gene mobile analysis map based on metagenomic binning both displayed the potential horizontal transfer ability of VFGs in the cows and environment. Our study revealed the prevalence, diffusion, and regulatory factors of VFGs in dairy cattle production systems, providing novel insights into reducing livestock VFGs and limiting their spread.
毒力因子基因（VFGs）对生态安全和动物健康构成潜在威胁，在畜牧业中受到越来越多的关注。奶牛作为主要的家畜之一，可能是 VFG 传播的重要来源。然而，奶牛胃肠道及其周围环境中 VFG 的分布、传播和进化尚不清楚。本研究共采集了奶牛、牛犊、初乳、养殖场废水和土壤样本 263 份。通过宏基因组学分析这些生态位中微生物组和 VFG 特征的变化。奶牛的 VFG 在瘤胃和粪便中存在明显差异，且受地域影响。优势 VFG 宿主受其微生物结构调控。奶牛初乳的灌胃使新生牛犊粪便中的 VFG 丰度急剧增加，肠杆菌科成为主要宿主。而饮食是牛犊 VFG 时间变化的主要驱动力。对于周围环境样本，水和土壤的 VFG 浓度更高，结构更稳定。此外，移动遗传元件与 VFG 之间的广泛相互作用以及基于宏基因组 binning 的基因移动分析图谱均显示了 VFG 在奶牛和环境中的潜在水平转移能力。本研究揭示了奶牛生产系统中 VFG 的流行、扩散和调控因素，为减少家畜 VFG 及其传播提供了新的思路。
