《Regulatory formation of VBNC state antibiotic-resistant bacteria in water induced by sub-lethal photocatalysis and their resuscitation mechanism》

Website: https://doi.org/10.1016/j.jhazmat.2025.140041

Graphical Abstract：

ABSTRACT:

The presence of antibiotic-resistant bacteria (ARB) in water poses serious threat to public safety. Worse still, to escape damage, ARB could enter viable but nonculturable (VBNC) state during water disinfection, and VBNC bacteria may resuscitate and further exposure to human, even causing serious disease. Herein, both regulatory formation mechanisms of VBNC bacteria induced by sub-lethal photocatalysis and its resuscitation mechanism were elucidated. After inducing for 1 h, >10⁸ CFU/mL E. coli of all strains including ARB entered VBNC state, demonstrated by losing culturability and decreasing cell length. After stress rescinded for 5–10 d, VBNC E. coli could resuscitate, with a gradually increased trendy within 20 d and then decreased slightly. This resuscitation was demonstrated by recovering cell length, culturability and growth to the extent as wild type state. However, resuscitated cells showed a higher antibiotic resistance than wild type cells. Furthermore, qPCR analysis indicates that repaired oxidative damage and induced changes in energy allocation were the driving force for resuscitation of VBNC E. coli. This study deepens our understanding of health risks associated with ARB entering and exiting VBNC state, and provides new insights into developing more effective strategies to water disinfection.