Inactivation Mechanisms of Pulsed Corona Discharge Plasma on Escherichia Coli and Staphylococcus Aureus Phages

Pathogenic virus brings tremendous threat to human lives, livelihoods, and public health. The nonthermal plasma (NTP) generated through pulsed corona discharge has aroused considerable interest in microbial inactivation. However, the mechanism of virus inactivation by NTP is not fully understood. This study presented the NTP by means of corona discharge in air with the multineedles plate electrode driven by a pulsed power, and the electrical and optical characteristics of corona discharge plasma were analyzed. The
Escherichia coli
phage (ECP) vB-EcoP-Bp4 and
Staphylococcus aureus
phage (SAP) vB-StaM-JTB were utilized to explore plasma inactivation effect and mechanism. The killing log value (KLV) results indicated that corona discharge plasma could inactivate the two kinds of bacteriophages effectively. DNA and protein analysis revealed that the NTP damaged both nucleic acids and proteins, consistent with the morphological observation. From the variation of H
$_{2}$
O
$_{2}$
and NO
$_{2}^{-}$
inside solution and its pH, it could be concluded that these strong oxidation reactive oxygen species (ROS) and reactive nitrogen species (RNS) induced by NTP would degrade the nucleic acid and protein, weakening bacteriophages replication ability and affecting the adsorption process of bacteriophages to infect the host bacteria.