Abstract：
Controlling the dissemination of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) is a global concern. While commonly used chlorine disinfectants can damage or even kill ARB, dissolved oxygen (DO) may affect the formation of reactive chlorine species. This leads to the hypothesis that DO may play roles in mediating the effectiveness of chlorine disinfection for antibiotic resistance. To this end, this study investigated the impacts of DO on the efficiency of chlorine disinfection for antibiotic resistance. The results revealed that DO could increase the inactivation efficiency of ARB under chloramine and free chlorine exposure at practically relevant concentrations. Reactive species induced by DO, including H2O2, O2-, and OH, inactivated ARB strains by triggering oxidative stress response and cell membrane damage. In addition, the removal efficiency of extracellular ARGs (i.e. tetA and blaTEM) was enhanced with increasing dosage of free chlorine or chloramine under aerobic conditions. DO facilitated the fragmentation of plasmids, contributing to the degradation of extracellular ARGs under exposure to chlorine disinfectants. The findings suggested that DO facilitates disinfection efficiency for antibiotic resistance in water treatment systems.
摘要：
控制抗生素抗性细菌(ARB)和抗生素抗性基因(ARGs)的传播是全球关注的问题。虽然常用的氯消毒剂可以破坏甚至杀死ARB，溶解氧（DO）可能会影响活性氯的形成。这导致了以下假设：DO可能在介导氯消毒对抗生素耐药性的有效性中起作用。为此,这项研究调查了DO对抗生素耐药性氯消毒效率的影响。结果表明，在实际相关浓度的氯胺和游离氯暴露下，DO可以提高ARB的失活效率。DO诱导的反应性物种，包括H2O2，O2-，哦,通过引发氧化应激反应和细胞膜损伤来灭活ARB菌株。此外,在好氧条件下，随着游离氯或氯胺用量的增加，胞外ARGs（即tetA和blaTEM）的去除效率提高。DO促进了质粒的片段化,在暴露于氯消毒剂的情况下，有助于细胞外ARG的降解。研究结果表明，DO可以提高水处理系统中抗生素耐药性的消毒效率。
