Non-negligible effects of sunlight irradiation on generation of VBNC-state antibiotic resistant bacteria in natural water
Zhang, Tingting Cheng, Fangyuan Fan, Linyi Zhang, Ya-Nan Qu, Jiao Peijnenburg, Willie JGM
Zhang, Tingting
Cheng, Fangyuan
Fan, Linyi
Zhang, Ya-Nan
Qu, Jiao
Peijnenburg, Willie JGM
Series / Report no.
Open Access
Type
Journal Article
Article
Article
Language
en
Date of publication
2025-04-23
Year of publication
Research Projects
Organizational Units
Journal Issue
Title
Non-negligible effects of sunlight irradiation on generation of VBNC-state antibiotic resistant bacteria in natural water
Translated Title
Published in
J Hazard Mater 2025:493:138397
Abstract
The viable but non-culturable (VBNC) state antibiotic resistant bacteria (ARB) poses significant environmental risk. The mechanism by which simulated sunlight irradiation induces ARB to enter the VBNC state remains unclear. This study systematically explored the photochemical generation mechanism of VBNC-ARB in natural water. Ampicillin-resistant Escherichia coli (AR E. coli) was selected as a representative ARB. The results showed that AR E. coli lost cultivability under sunlight with 91.1 % of AR E. coli entering the VBNC state. Suwannee River fulvic acid (SRFA) slightly enhanced this effect and can induce 95.9 % of AR E. coli into the VBNC state. Under sunlight exposure, oxidative stress and the toxin-antitoxin (TA) system in AR E. coli were identified as key factors in inducing the VBNC state. This process was accompanied by a deterioration in cell membrane fluidity, upregulation of cell wall and outer membrane-related genes, and toxin-mediated inhibition of DNA replication. Importantly, AR E. coli retained intact antibiotic resistance genes (ARGs) and could reactivate these genes in the dark, with SRFA promoting this recovery. Therefore, VBNC-ARB remains antibiotic resistance and increases virulence expression, consequently increasing human health risks. These findings underscore the need for effective strategies to manage VBNC-ARB in environmental systems.