Inactivation of multidrug-resistant bacteria using cold atmosphericpressure plasma technology

Xingxing Wang ¹ Mengzhen Chen ² Ye Lu ² Peihao Yu ¹ Chen Zhang ¹ Chao Huang ³ Zhibiao Yang ³ Yan Chen ^2* Jian-cang ZHOU ^1*

• ¹ Department of Critical Care Medicine, Sir Run Run Shaw Hospital, School of Medicine, Graduate School, Zhejiang University, Hangzhou, China
• ² Department of Infectious Diseases, Sir Run Run Shaw Hospital, School of Medicine, Graduate School, Zhejiang University, Hangzhou, China
• ³ Panasonic Home Appliances (China) Co., Ltd, Hangzhou, China

Objective: This study aimed to investigate the impact of cold atmospheric-pressure plasma (CAP) on multidrug-resistant (MDR) bacteria on various surfaces under nosocomial circumstances and the underlying mechanism.Method: Four common MDR bacteria (carbapenem-resistant Acinetobacter baumannii, carbapenemresistant Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and carbapenemresistant Klebsiella pneumoniae) were inoculated on nosocomial surfaces, which were subsequently exposed to CAP. Then the bacteria from surfaces were recovered and diluted. The killing curve was analyzed to evaluate the sterilization effects of CAP. Electron microscopy was used to evaluate the changes in cell morphology.Result: In the CAP-producing device, most of the MDR bacteria were nearly inactivated after 2 h of CAP treatment. Under the simulated ward, CAP exerted an inactivating effect on MDR bacteria. Scanning electron microscopy revealed that the surface of MDR bacteria became blurred, the bodies ruptured and adhered to each other after CAP treatment. The cell walls were thinner as revealed by transmission electron microscopy.Conclusion: CAP could inactivate the most common MDR bacteria on nosocomial surfaces in simulation ward settings by destroying the structure of pathogens. Our data provided insights into the sterilization of MDR bacteria using CAP and suggested a novel in-hospital disinfection alternative.