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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.