Chemical Changes in Nonthermal Plasma-Treated N-Acetylcysteine (NAC) Solution and Their Contribution to Bacterial Inactivation

• Published in: Scientific reports Vol. 6; p. 20365
• Main Authors: Ercan, Utku K, Smith, Josh, Ji, Hai-Feng, Brooks, Ari D, Joshi, Suresh G
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 02-02-2016
• Subjects: Acetylcysteine; Acetylcysteine - chemistry; Acetylcysteine - pharmacology; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antimicrobial activity; Antimicrobial agents; Biofilms; Chemical reactions; Chemical speciation; Colorimetry; E coli; Hydrogen-Ion Concentration; Inactivation; Magnetic Resonance Spectroscopy; Microbial Viability - drug effects; Microorganisms; Multidrug resistance; Nitrates - chemistry; Nitrites - chemistry; NMR; Nuclear magnetic resonance; Peroxynitrite; Pharmaceutical Solutions - chemistry; Pharmaceutical Solutions - pharmacology; Plasma; Plasma Gases - chemistry; Reactive nitrogen species; Reactive Nitrogen Species - chemistry; Reactive oxygen species; Reactive Oxygen Species - chemistry; Spectrometry; Spectroscopy, Fourier Transform Infrared
• ISSN: 2045-2322
• DOI: 10.1038/srep20365

In continuation of our previous reports on the broad-spectrum antimicrobial activity of atmospheric non-thermal dielectric barrier discharge (DBD) plasma treated N-Acetylcysteine (NAC) solution against planktonic and biofilm forms of different multidrug resistant microorganisms, we present here the chemical changes that mediate inactivation of Escherichia coli. In this study, the mechanism and products of the chemical reactions in plasma-treated NAC solution are shown. UV-visible spectrometry, FT-IR, NMR, and colorimetric assays were utilized for chemical characterization of plasma treated NAC solution. The characterization results were correlated with the antimicrobial assays using determined chemical species in solution in order to confirm the major species that are responsible for antimicrobial inactivation. Our results have revealed that plasma treatment of NAC solution creates predominantly reactive nitrogen species versus reactive oxygen species, and the generated peroxynitrite is responsible for significant bacterial inactivation.