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Inactivation of multidrug-resistant pathogens and Yersinia enterocolitica with cold atmospheric-pressure plasma on stainless-steel surfaces

Lis, Karolina A., Kehrenberg, Corinna, Boulaaba, Annika, von Köckritz-Blickwede, Maren, Binder, Sylvia, Li, Yangfang, Zimmermann, Julia L., Pfeifer, Yvonne, Ahlfeld, Birte
International journal of antimicrobial agents 2018 v.52 no.6 pp. 811-818
Acinetobacter, Enterococcus, Escherichia, Klebsiella, Staphylococcus, Yersinia, antibiotic resistance, atmospheric pressure, bacteria, bovine serum albumin, electric potential, methicillin, multiple drug resistance, pathogens, propidium, stainless steel
The objective of this study was to investigate the impact of cold atmospheric-pressure plasma (CAP) produced by a surface micro-discharge plasma source as a new strategy to combat the transmission of five multidrug-resistant (MDR) pathogens and Yersinia enterocolitica on typical hospital- and food-producing surfaces, e.g. stainless-steel. Approximately 106 CFU/cm2 of vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and Y. enterocolitica were inoculated on a 3.14-cm2 stainless-steel surface. Bovine serum albumin (BSA) (3%) was used as a disruptive factor simulating natural organic material. The inoculated surfaces were subsequently exposed to CAP, generated by a peak-to-peak voltage of 10 kV with sinusoidal waveform and a frequency of 2 kHz, for 5, 10 and 20 min, respectively. Fluorescent staining with propidium iodide and SYTOTM 9 was used to demonstrate the manner of bacterial cell damage. Significant (P < 0.05) inactivation of 1.68 ± 0.17 up to 2.80 ± 0.17 log steps was achieved after 5 min of CAP treatment. However, bacterial reduction could be increased to 3.35 ± 0.1 up to 5.17 ± 0.67 log steps after 20 min of CAP treatment. Bacterial cells covered with BSA were statistically significantly less inactivated by CAP. Fluorescent staining showed a predominant level of orange-stained, sublethally damaged bacterial cells after 10 min of CAP treatment. In conclusion, CAP has the ability to inactivate MDR bacterial pathogens on stainless-steel surfaces. Further research is required to investigate the clinical features of CAP.