In vitro virucidal activity of chemical compounds against porcine transmissible gastroenteritis virus and porcine respiratory coronavirus

Porcine transmissible gastroenteritis virus (TGEV) and porcine respiratory coronavirus (PRCV) are enveloped, single-stranded RNA viruses belonging to the genus Alphacoronavirus in the family Coronaviridae. In the absence of effective treatments, these viruses may lead to significant economic losses in the swine industry. To date, there is no or limited information about the efficiency of disinfectants against TGEV and PRCV. Therefore, in this study, we investigated the virucidal activity of eleven chemical compounds against TGEV and PRCV using a quantitative suspension test method based on the European Standard EN 14675. The results revealed that caustic soda (3%, 2%, 1%), potassium peroxymonosulfate (2%, 1%, 0.5%), and 80% ethanol exhibited effective virucidal activity (reduction ≥ 4 log10TCID50/ml) under low- and high-level soiling conditions against both TGEV and PRCV. Ethanol (60% and 40%) showed virucidal efficacy against PRCV under low- and high soiling conditions but against TGEV only under low soiling conditions. Sodium hypochlorite (1.5%, 1%, 0.5%) was effective only against TGEV in low-level soiling conditions but was ineffective against PRCV. Furthermore, acetic acid (3.5%, 2.5%, 1.5%), hydrogen peroxide (0.5%, 1%, 2%), and phenol (1%, 1.5%, 2%) did not result in a ≥ 4 log10TCID50/ml reduction in the PRCV and TGEV viral titers under both tested conditions, so these compounds were found to be ineffective. Benzalkonium chloride (0.5%, 1%, 1.5%), formaldehyde (0.125%, 0.275%, 0.5%), and glutaraldehyde (0.1%, 0.5%, 1%) were found to be cytotoxic, limiting the detection of viral infectivity reduction to less than 4 log10TCID50/ml. Our study also revealed that caustic soda and potassium peroxysulfate were the most stable disinfectants and that organic matter notably reduced the activity of sodium hypochlorite. To the best of our knowledge, this is the first report on in vitro testing of chemicals that can help prevent the spread and transmission of PRCV and TGEV.