摘要
      众所周知，消毒会极大地改变水中细菌的特性，在富营养化条件下会发生高水平基因转移（HGT）频率。有趣的是，在这项研究中，这两种看似无关的现象与可能通过日常水消毒增加的结合频率的滞后反应密切相关。选择三种消毒方法（紫外线、氯和紫外线/氯）来研究消毒后继续培养阶段ARGs结合频率的增加。结果表明，在共孵育24小时后，所有消毒处理的偶联转移频率都受到抑制。出乎意料的是，在共培养3-7天后，与对照组相比，氯（30分钟）和紫外线/氯（1分钟）组的HGT频率增加了2.71–5.61倍和5.46–13.96倍，但紫外线照射组没有。首次发现了一种被忽视的滞后反应，即氧化消毒诱导的休眠促进了ARGs的结合转移。此外，从（1）膜渗透性、（2）偶联调节系统、（3）外排泵系统和（4）氧化应激系统中获得了机制见解，表明增强外排和氧化应激在ARGs传播中的关键作用。最后，对已知的氧化消毒的即时效果进行了比较，以解决该研究领域的争议，提出供体细菌的休眠水平是评估其是否能促进HGT过程的关键。这项研究对阐明氧化消毒后ARGs的传播具有重要的环境意义。
Abstract
Disinfection is known to greatly alter bacterial characteristics in water, and high horizontal gene transfer (HGT) frequency occurs in eutrophic conditions. Interestingly, these two seemingly irrelevant phenomena were closely linked by a lagging response of the increased conjugation frequency probably via daily water disinfection in this study. Three disinfection methods (UV, chlorine, and UV/chlorine) were selected to investigate the increased frequency of conjugation of ARGs during the stage of continuing culture after disinfection. The results showed that the conjugative transfer frequency was inhibited for all disinfection treatments after 24 h of co-incubation. Unexpectedly, after 3–7 days of co-cultivation, the HGT frequencies were increased by 2.71–5.61-fold and 5.46–13.96-fold in chlorine (30 min) and UV/chlorine (1 min) groups compared to the control, but not in UV-irradiated groups. A neglected lagging response was found for the first time, i.e., oxidative disinfection-induced dormancy promotes conjugative transfer of ARGs. Furthermore, mechanistic insights were gained from (1) membrane permeability, (2) conjugation-regulated system, (3) efflux pump system, and (4) oxidative stress system, suggesting the critical role of enhancing efflux and oxidative stress in the propagation of ARGs. Finally, the known instantaneous effect of oxidation disinfection was compared to address the controversial debate in this research field, proposing that the dormancy level of donor bacteria is the key to evaluating whether it can promote the HGT process. This study has important environmental implications for elucidating the transmission of ARGs after oxidation disinfection.

https://www.sciencedirect.com/science/article/abs/pii/S0043135422007515