Efficacy of argon cold atmospheric pressure plasma jet on hospital surface decontamination and its impact on the surface property

Abstract The emergence of antimicrobial resistance has become a major contributor to healthcare-associated infections. Recently, the cold atmospheric pressure plasma jet (CAPJ) discharges have garnered attention of the researchers globally for their novel antimicrobial property. This research evaluated the effectiveness of an in-house developed CAPJ on the inactivation of multidrug-resistant (MDR) E. coli and S. aureus artificially inoculated over stainless steel and aluminium test surfaces. A greater than ∼5 log 10 reduction of E. coli , whereas reduction of ∼3.4–4.6 log 10 for S. aureus on the test surfaces was achieved on 180 s CAPJ exposure. Extremely low D- values (in the range of ∼27–63 s) were recorded for both isolates. In addition, this study assessed the impact of repeated CAPJ exposure on surface property, by replicating the process of hospital surface decontamination. Surface properties such as wettability, roughness, and elemental composition varied non-linearly on repetitive Ar CAPJ exposure on test surfaces. It was observed that the identified gas-phase species such as excited atoms (Ar I, and O I), positive ions (NO + , O 2 + , OH + , O + , N 2 + , Ar + , etc), negative ions (N 2 O 2 − , N 2 O 3 − , NO 3 − , NO 2 − , etc), radical RONS (OH•), and non-radical RONS (O I, NO + , OH + , N 2 O 3 − , NO 3 − , NO 2 − , etc) would contribute to bacterial load reduction on the test surface along with any alteration in surface characteristic. There may be chemical and physical processes involved in the above activity. This investigation into understanding the effects of CAPJ surface decontamination on surface properties would aid in determining its potential applications in healthcare settings.