摘要
      全球范围内都可以看到含盐地下水，各种因素可以对抗生素耐药性基因（ARGs）（即耐药性组）施加复杂的选择压力。然而，人们对盐水中抗生素耐药性及其决定因素的综合概况知之甚少。本研究比较研究了生物（即微生物群和可移动遗传元素）和非生物（即水参数和抗生素）因素在盐度梯度上的动力学，并进一步探讨了它们在形成盐水-地下水抗性中的作用。总的来说，耐药组含有166个ARG，对16类抗生素产生耐药性，丰度为0.002–0.306拷贝/细胞，显示出显著的变异。微生物群的β-多样性直接影响耐药组的丰度，而抗生素（主要是磺胺类药物）和流动组直接影响耐药组成。环境变量，如有机碳、以硫酸盐为主的高盐度和金属（如钴、钾和锂），通过作用于微生物群和移动体间接影响抗性。此外，在高盐度地下水中，抗性体与迁移体和微生物群的相互相关性减弱，表明在高盐度地下水中，抗性体的水平基因转移潜力较低。ARGs在地下水抵抗体中的主要宿主和迁移潜力随盐度梯度而变化。这些发现为盐水中抗菌药物的管理提供了重要的见解。
Abstract
Saline groundwater is witnessed globally, where various factors can exert complex selective pressure on antibiotic resistance genes (ARGs) (i.e., the resistome). However, the comprehensive profile of the antibiotic resistome and its determining factors in saline groundwater is poorly understood. This study comparatively investigated the dynamics of biotic (i.e., microbiota and mobile genetic elements) and abiotic (i.e., water parameters and antibiotics) factors over salinity gradients and further explored their roles in shaping the saline groundwater resistome. Overall, the resistome harbored 166 ARGs conferring resistance to 16 classes of antibiotics, with an abundance of 0.002–0.306 copies/cell, showing significant variation. The microbiota β-diversity directly influenced resistome abundance, whereas antibiotics (mainly sulfonamides) and the mobilome directly affected resistome composition. Environmental variables, such as organic carbon, high sulfate-dominated salinity, and metals (e.g., cobalt, potassium, and lithium), indirectly affected the resistome by acting on the microbiota and mobilome. Moreover, inter-correlations of the resistome with mobilome and microbiota weakened in groundwater with high salinity, indicating lower horizontal gene transfer potential of the resistome in high-salinity groundwater. The major hosts and mobility potentials of ARGs in the groundwater resistome changed across the salinity gradients. These findings offer vital insights into the management of antimicrobials in saline groundwater.

https://www.sciencedirect.com/science/article/abs/pii/S030438942300016X