Inactivation of antibiotic resistant bacterium Escherichia coli by electrochemical disinfection on molybdenum carbide electrode

Abstract

Antibiotic-resistant bacteria (ARB) pose a substantial threat to public health worldwide. Electrochemistry, as a low energy consumption and environmentally friendly technique, is ideal for inactivating ARB. This study explored the utility of electrochemical disinfection (ED) for inactivating ARB (Escherichia coli K-12 LE392 resistant to kanamycin, tetracycline, and ampicillin) and the regrowth potential of the treated ARB. The results revealed that 5.12-log ARB removal was achieved within 30 min of applying molybdenum carbide as the anode and cathode material under a voltage of 2.0 V. No ARB regrowth was observed in the cathode chamber after 60 min of incubation in unselective broth, demonstrating that the process in the cathode chamber was more effective for permanent inactivation of ARB. The mechanisms underlying the ARB inactivation were verified based on intercellular reactive oxygen species (ROS) measurement, membrane integrity detection, and genetic damage assessment. Higher ROS production and membrane permeability were observed in the cathode and anode groups (p < 0.001) compared to the control group (0 V). In addition, the DNA was more likely to be damaged during the ED process. Collectively, our results demonstrate that ED is a promising technology for disinfecting water to prevent the spread of ARB.