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Chlorine dioxide is a globally recognized green and efficient disinfectant. This study aims to investigate the bactericidal mechanism of chlorine dioxide using beta-hemolytic Streptococcus (BHS) CMCC 32210 as a representative strain. BHS was exposed to chlorine dioxide, the minimum bactericidal concentration (MBC) values of chlorine dioxide against BHS were determined by the checkerboard method in preparation for subsequent tests. Cell morphology was observed using electron microscopy. Protein content leakage, adenosine triphosphatase (ATPase) activity, and lipid peroxidation were determined by kits, and DNA damage was determined using agar gel electrophoresis. The concentration of chlorine dioxide during disinfection showed a linear relationship with the concentration of BHS. Scanning electron microscopy (SEM) results showed that chlorine dioxide caused significant damage to the cell walls of BHS at a concentration of 50 mg/L, but had no significant effect on Streptococcus exposed to different exposure times. Furthermore, the extracellular protein concentration increased with increasing chlorine dioxide concentration, while the total protein content remained unchanged. The activities of Na + /K + -ATPase and Ca 2+ /Mg 2+ -ATPase decreased with increasing chlorine dioxide concentration. Chlorine dioxide treatment led to significant lipid peroxidation and DNA degradation in BHS. Leakage of intracellular components indicated that chlorine dioxide damaged the cell membrane of BHS. Chlorine dioxide exposure resulted in oxidative damage to lipids and proteins, which negatively impacted the cell wall and membrane of Streptococcus. This caused increased permeability and inactivation of key enzymes (Na + /K + -ATPase and Ca 2+ /Mg 2+ -ATPase) involved in respiratory metabolism, ultimately leading to DNA degradation and bacterial death due to either content leakage or metabolic failure.

Objectives: To estimate the unintentional poisoning burden and risk factors in China from 1990 to 2015., Methods: We extracted data from the Global Burden of Disease Study 2015 to compare mortality, prevalence, disability-adjusted life years (DALYs), years of life lost, years lived with a disability, and risk factors of unintentional poisoning in China. We determined the median of the percent change and 95% uncertainty interval for the period between 1990 and 2015., Results: The age-standardized unintentional poisoning death rate decreased by 61.8% from 1990 (4.1 per 100 000) to 2015 (1.6 per 100 000). The age-standardized prevalence decreased from 1990 (87.9 per 100 000) to 2010 (39.0 per 100 000), but rebounded in 2015 (42.6 per 100 000). All risk factors combined accounted for 14.9% of unintentional poisoning DALYs in 2015. The leading risk factors for unintentional poisoning DALYs were alcohol and drug use and occupational risks., Conclusions: China has made substantial progress in reducing the mortality attributable to unintentional poisoning, but the prevalence and absolute number of patients has been increasing again since 2010. The growing contribution from alcohol and drug use requires increased attention.