Nanowire electroporation-induced cell pores on antibiotic-resistant bacteria to promote chlorine permeation for eliminating intracellular antibiotic resistance genes

Conventional chlorination (Cl2) is inefficient to eliminate intracellular antibiotic resistance genes (i-ARGs) of antibiotic-resistant bacteria (ARB) due to the chlorine permeation barrier and oxidative competition of cell wall/ membrane. Herein, we proposed an efficient strategy by constructing synergistic nanowire-induced electroporation (DC-EP) and Cl2 (DC-EP/Cl2) with H2-reduced TiO2 nanowire (TiOxNW) electrodes, attempting to promote i-ARG removal via DC-EP-induced cell damage for chlorine permeation and i-ARG leakage. DC-EP/Cl2 (-3.7 log and -60.5 J/L/log) exhibited excellent synergistic effects for ARB inactivation (Escherichia coli) and i-ARG removal (tet(W), aac(3)-II, and blaTEM-1), which achieved much larger i-ARG removal and lower energy consumption than the individual 1.5 V-DC-EP (-0.05 log) and 10 mg/L-Cl2 (-0.5 log and -262.0 J/L/log). Analyses of i-ARG/e-ARG abundances, bacterial cell integrity, and cell morphology indicated that DC-EP-induced cell pores provided channels of chlorine permeation, which was accompanied with oxidative enlargement of cell pores for i-ARG leakage and subsequent degradation. DC-EP/Cl2 exhibited 15-90 times lower frequency of horizontal gene transfer than the individual Cl2 disinfection. The TiOxNW-based DC-EP/Cl2 exhibited excellent stability of i-ARG removal (undetectable ARG abundance and -20.3 J/L/log) for treating 103 CFU/mL ARB-contaminated tap water within 7-day continuous operation, suggesting its great application potential to alleviate ARG dissemination risk for drinking water.