Purpose: The goal of this research was to determine the ability of non-thermal plasma to inactivate human enteric virus surrogates on stainless steel surfaces.
Methods: Cultivable human norovirus surrogates, feline calicivirus (FCV-F9) and murine norovirus (MNV-1), and bacteriophage MS2 at ~7 log plaque forming units (PFU)/ml were inoculated and dried on sterile stainless steel coupons. These coupons were treated with the patented One Atmosphere Uniform Glow Discharge Plasma for 0, 1, 2, 5, and 10 min. Recovered viruses were evaluated by plaque assays using their respective host cells and compared to untreated controls. Each experiment was replicated thrice in duplicate. Data was statistically analyzed using SAS at P < 0.05.
Results: Data obtained showed that FCV-F9 was the most sensitive among the tested viruses to cold-plasma treatment, followed by MS2 and MNV-1. FCV-F9 showed reduction of 2.34 and 3.55 log PFU after 1 and 2 min, respectively and to non-detectable levels after 5 and 10 min. MS2 was reduced by 2.03 and 5.46 log PFU after 2 and 5 min, respectively and to non-detectable levels after 10 min. MNV-1 was reduced by 0.56, 1.61, 1.95, and 3.16 log PFU after 1, 2, 5 and 10 min, respectively.
Significance: Non-thermal atmospheric plasma shows promise for use as an alternative disinfection technology against human enteric virus surrogates on stainless steel surfaces to prevent viral transmission. The technology has potential application for microbial inactivation on produce and other thermally-sensitive food products to prevent foodborne viral outbreaks.