Inactivation of SARS-COV-2 by various surfactants

Introduction: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing the global pandemic is an enveloped virus and expected to be susceptible to some surfactants. The efficacy of the commercially available disinfectants and cleaners against this virus has been well examined so far, but only few reports mentioned about the efficacy of each surfactant alone. Objectives: This study aimed to evaluate the virucidal efficacy of various surfactants against SARS-CoV-2 (JPN/TY/WK-521). In addition, it also aimed to examine the presence of correlation between the virucidal efficacy and cytotoxicity of each surfactant. Methods: For this study, the experiments dealing with the novel coronavirus were carried out at the Research Institute for Microbial Diseases (Osaka University), while the cytotoxicity tests were performed at the Saraya Microbiologicial Research Center (Saraya Co., Ltd). The virucidal efficacy of each surfactant (cationic, anionic, amphoteric and non-ionic surfactant;0.01% ∼ 5.00%) was evaluated according to EN 14476 (dirty conditions). Their cytotoxicity was then examined by MTT assay. Results: The performance of EN 14476 with SARS-CoV-2 demonstrated that the cationic surfactant showed high virucidal efficacy. Although not as high as that of the cationic surfactant, some nonionic and amphoteric surfactants also showed relatively good virucidal efficacy, while the rest did not. After evaluation of cytotoxicity, a good correlation between the virucidal efficacy and the cytotoxicity of each surfactant was observed;the higher the cytotoxicity, the higher the virucidal efficacy. Conclusion: All of the tested cationic surfactants showed high virucidal efficacy and some nonionic and amphoteric surfactants had relatively highly virucidal efficacy. The evaluation of this strain has been finished. Further studies on the comparison of surfactant efficacy to other enveloped viruses with the original strain would bring some new insights to this research.