TY - JOUR
T1 - Mechanisms underlying the effect of chlorination and UV disinfection on VBNC state Escherichia coli isolated from hospital wastewater
AU - Zhu, Lin
AU - Shuai, Xinyi
AU - Xu, Like
AU - Sun, Yujie
AU - Lin, Zejun
AU - Zhou, Zhenchao
AU - Meng, Lingxuan
AU - Chen, Hong
N1 - Funding Information:
This work was supported by National Natural Science Foundation of China (Grants 21876147 ) and Zhejiang University Global Partnership Fund . The authors would like to express their gratitude to Analysis Center of Agrobiology and Environmental Science of Zhejiang University for the electron microscope analysis.
PY - 2022/2/5
Y1 - 2022/2/5
N2 - The occurrence of viable but non-culturable (VBNC) bacteria in the wastewater system poses a huge threat to environmental and public health, in particular in hospital wastewater treatment system (HWTS). HWTS-oriented studies have been conducted to assess the effectiveness of chlorination and UV disinfection using indigenous bacteria. Results revealed that the VBNC Escherichia coli and ARGs remained persistent even at high chlorination (12 mg/L for 2.5 h) and UV doses (1000 mJ/cm2). The molecular mechanisms underlying chlorination-/UV-induced VBNC state in E. coli were explored through the transcriptomics and results suggested that most energy-dependent physiological activities (e.g., metabolism) have been suppressed in VBNC E. coli, while the pathogenicity-related genes varied insignificantly compared to the culturable cells, indicating that the VBNC E. coli could potentially display pathogenicity. Further Galleria mellonella model experiment has confirmed that although the disinfection-induced VBNC state made cells less infectious, these cells could regain their pathogenicity after resuscitation. This in vitro study can be used as a reference for studies on infections from VBNC bacteria and highlights the health risk due to VBNC pathogens in hospital effluents. There is a need to develop effluent standards specifically for healthcare facilities, and a stricter downstream disinfection strategy should be considered for the removal of VBNC cells and ARGs in the effluent.
AB - The occurrence of viable but non-culturable (VBNC) bacteria in the wastewater system poses a huge threat to environmental and public health, in particular in hospital wastewater treatment system (HWTS). HWTS-oriented studies have been conducted to assess the effectiveness of chlorination and UV disinfection using indigenous bacteria. Results revealed that the VBNC Escherichia coli and ARGs remained persistent even at high chlorination (12 mg/L for 2.5 h) and UV doses (1000 mJ/cm2). The molecular mechanisms underlying chlorination-/UV-induced VBNC state in E. coli were explored through the transcriptomics and results suggested that most energy-dependent physiological activities (e.g., metabolism) have been suppressed in VBNC E. coli, while the pathogenicity-related genes varied insignificantly compared to the culturable cells, indicating that the VBNC E. coli could potentially display pathogenicity. Further Galleria mellonella model experiment has confirmed that although the disinfection-induced VBNC state made cells less infectious, these cells could regain their pathogenicity after resuscitation. This in vitro study can be used as a reference for studies on infections from VBNC bacteria and highlights the health risk due to VBNC pathogens in hospital effluents. There is a need to develop effluent standards specifically for healthcare facilities, and a stricter downstream disinfection strategy should be considered for the removal of VBNC cells and ARGs in the effluent.
KW - Disinfection methods
KW - Hospital wastewater treatment system (HWTS)
KW - Pathogenicity
KW - Resuscitation
KW - Viable but non-culturable (VBNC)
UR - http://www.scopus.com/inward/record.url?scp=85115136372&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2021.127228
DO - 10.1016/j.jhazmat.2021.127228
M3 - Article
AN - SCOPUS:85115136372
SN - 0304-3894
VL - 423
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
IS - Part B
M1 - 127228
ER -