Oxidative damage of antibiotic resistant E. coli and gene in a novel sulfidated micron zero-valent activated persulfate system

Antibiotic resistant bacteria and genes, as emerging pollutants, are threatening public health. In this study, sulfidated micron zero-valent iron (S-mZVI) activated persulfate (SMP) system was used to eliminate antibiotic resistant E. coli (AR E. coli) and antibiotic resistant gene (ARG). S-mZVI exhibited excellent activation of persulfate, which could completely remove AR E. coli within 30 min. The oxidative damage of AR E. coli cell was systemically studied by transmission electron microscopy, fluorescence microscopy, flow cytometry and malondialdehyde analysis. Concentrations of TN and TOC in SMP system were conducted to evaluate the oxidation and mineralization ability for cellular substances in AR E. coli cell. Moreover, removal efficiencies of cell-associated ARG (TetB) and 16S rRNA in SMP system were 2.9 and 2.2 log, respectively. Study on the presence and role of main reactive oxygen species (SO4·- and HO·) in SMP system suggested that SO4·- and HO· are key factors when considering membrane lipid oxidation and removal of 16S rRNA and ARG. This study provided a promising treatment method to inhibit antibiotic resistance and revealed the oxidative damage of AR E. coli and gene under SO4·- involved system.