摘要
      病原体中抗生素耐药性基因（ARGs）的发生和发展对全球健康构成了严重威胁。农业土壤为病原体和ARGs提供了蓄水池，与公共卫生和食品安全密切相关。特别是，金属压力为ARGs提供了更长期的选择压力，而气候变化是ARGs传播的“威胁乘数”。然而，人们对金属污染对农业土壤中病原体和ARGs的影响及其对持续气候变化的敏感性知之甚少。为了填补这一空白，在开放式室（OTCs）中进行了盆栽实验，以研究汞（Hg）污染对环境和高CO2浓度下土壤病原体和ARGs分布的影响。结果表明，在两种CO2浓度下，汞污染土壤中常见植物和人类病原体的相对丰度显著增加。在两个CO2水平下，汞污染是外排泵和攻击性毒力因子（粘附和分泌系统）激活的积极效应。汞污染引起的外排泵的激活可能有助于某些病原体的毒力或适应性的变化。总的来说，我们的研究强调了外排泵在汞胁迫下作为抗生素耐药性和病原体毒力的交叉点的关键作用。
Abstract
The occurrence and development of antibiotic resistance genes (ARGs) in pathogens poses serious threatens to global health. Agricultural soils provide reservoirs for pathogens and ARGs, closely related to public health and food safety. Especially, metals stress provides more long-standing selection pressure for ARGs, and climate change is a “threat multiplier” for the spread of ARGs. However, little is known about the impact of metals contamination on pathogens and ARGs in agricultural soils and their sensitivity to ongoing climate changes. To fill this gap, a pot experiment was conducted in open-top chambers (OTCs) to investigate the influence of mercury (Hg) contamination on the distribution of soil pathogens and ARGs under ambient and elevated CO2 concentration. Results showed that the relative abundance of common plant and human pathogens increased significantly in Hg-contaminated soil under two CO2 concentrations. Hg contamination was a positive effector of the activation of efflux pumps and offensive virulence factors (adhere and secretion system) under two CO2 levels. Activation of efflux pumps caused by Hg contamination might contribute to changes of virulence or fitness of certain pathogens. Overall, our study emphasizes the critical role of efflux pumps as an intersection of antibiotic resistance and pathogen's virulence under Hg stress.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722079347