Table_2_Anthropogenic disturbance promotes the diversification of antibiotic resistance genes and virulence factors in the gut of plateau pikas (Ochotona curzoniae).DOCX

The prevalence and transmission of antibiotic resistance genes (ARGs) and virulence factors (VFs) pose a great threat to public health. The importance of pollution in determining the occurrence of ARGs and VFs in wildlife is poorly understood. Using a metagenomic approach, this study investigates the composition and functional pathways of bacteria, ARGs, and VFs in the gut microbiome of Plateau pikas in regions of medical pollution (MPR), heavy tourist traffic (HTR), and no contamination (NCR). We found that the abundance of probiotic genera (Clostridium, Eubacterium, Faecalibacterium, and Roseburia) were significantly lower in the HTR. The metabolic pathways of replication and repair in the endocrine and nervous systems were significantly enriched in the MPR, whereas endocrine and metabolic diseases were significantly enriched in the NCR. The Shannon and Gini–Simpson α-diversity indices of ARGs were highest in the HTR, and there were significant differences in β-diversity among the three regions. The resistance of ARGs to glycopeptide antibiotics increased significantly in the MPR, whereas the ARGs for aminocoumarins increased significantly in the HTR. The diversity of mobile genetic elements (MGEs) was significantly higher in the MPR than in other regions. We observed a strong positive correlation between ARGs and pathogenic bacteria, and the network structure was the most complex in the MPR. There were significant differences in the β-diversity of VFs among the three regions. Medical pollution led to significant enrichment of fibronectin-binding protein and PhoP, whereas tourism-related pollution (in the HTR) led to significant enrichment of LPS and LplA1. Our study indicates that environmental pollution can affect the structure and function of gut microbes and disseminate ARGs and VFs via horizontal transmission, thereby posing a threat to the health of wild animals.

抗生素抗性基因（antibiotic resistance genes, ARGs）与毒力因子（virulence factors, VFs）的流行与传播对公共健康构成严重威胁。目前学界对污染如何调控野生动物体内ARGs与VFs的发生规律仍缺乏深入认知。本研究采用宏基因组学方法，探究了医疗污染区（medical pollution region, MPR）、旅游高负荷区（heavy tourist traffic region, HTR）以及无污染区（no contamination region, NCR）内高原鼠兔肠道菌群中细菌、ARGs与VFs的组成及功能通路。研究发现，旅游高负荷区的益生菌属（梭菌属Clostridium、真杆菌属Eubacterium、粪杆菌属Faecalibacterium以及罗氏菌属Roseburia）的丰度显著降低。内分泌与神经系统的复制修复代谢通路在医疗污染区显著富集，而内分泌与代谢疾病相关代谢通路在无污染区显著富集。ARGs的Shannon指数与Gini–Simpson α多样性指数在旅游高负荷区最高，且三个区域间的β多样性存在显著差异。医疗污染区的ARGs对糖肽类抗生素的抗性显著增强，而旅游高负荷区的ARGs对氨基香豆素类抗生素的抗性显著提升。可移动遗传元件（mobile genetic elements, MGEs）的多样性在医疗污染区显著高于其他区域。本研究观察到ARGs与致病菌间存在显著正相关关系，且其共现网络结构在医疗污染区最为复杂。三个区域间VFs的β多样性存在显著差异。医疗污染会显著富集纤连蛋白结合蛋白与PhoP，而旅游相关污染（即旅游高负荷区）会显著富集脂多糖（LPS）与LplA1。本研究表明，环境污染可改变肠道菌群的结构与功能，并通过水平传播扩散ARGs与VFs，进而对野生动物的健康构成威胁。