1.In Vitro Virucidal Effect of Povidone-Iodine Against SARS-CoV-2
Kyeong Ryeol SHIN ; Kyunghee KWAK ; Chunguang CUI ; Joon-Yong BAE ; Woosung HONG ; Man-Seong PARK
Journal of Bacteriology and Virology 2020;50(3):195-202
As of September 2020, SARS-CoV-2 has infected over 30 million people worldwide, and the death toll has now risen to 950,000. Given that Povidone-iodine (PVP-I) had consistently been showing the virucidal efficacy against various types of viruses, such as SARS-CoV, MERS-CoV, and Ebola, we conducted this study to figure out the virucidal effect against SARS-CoV-2 by using a viral plaque assay. We performed Kill-Time assays to assess the viral inactivation of SARS-CoV-2 contaminants after the application of the PVP-I product (Betadine® Throat Spray, PVP-I 0.45%). This test consisted of clean and dirty conditions and was designed to check the viral titers at a contact time of 60 seconds, which were evaluated by plaque-reduction rates in Vero cells. This PVP-I product fully achieved ≥4 log 10 reductions in viral titers under both clean and dirty conditions. This level of reduction, ≥4 log 10 (99.99%), in viral titers presented to be effective in terms of virucidal efficacy, according to the European standards, EN14476. This study revealed the virucidal efficacy of Betadine® Throat Spray against SARS-CoV-2 virus. Given that the convenience and availability of this product, we think that it may contribute to inhibit viral infection and transmissibility as an active type of personal protective equipment (PPE) by managing the hygiene of patients and medical professionals.
2.Porcine epidemic diarrhea viruses from Vietnam: isolation, characterization, and neutralizing activity
Van Tan DO ; Quang Lam TRUONG ; Hoai Thu DAO ; Thi Lan NGUYEN ; Minna SHIN ; Kyeong Ryeol SHIN ; Tae-Wook HAHN
Korean Journal of Veterinary Research 2023;63(2):e18-
Porcine epidemic diarrhea (PED) is characterized by acute enteritis, watery diarrhea, weight loss, dehydration, and death, with high mortality in neonatal piglets. In this study, 3 virus isolates collected in Vietnam between 2016 and 2017 were propagated successfully in Vero cells at high virus titers. Sequence analysis of the full-length spike (S) gene showed that all 3 isolates belong to genogroup 2b, which is closely related to other prevalent Asian strains. A comparison of the amino acid sequence revealed a 98.19% to 99.13% homology with the Vietnam isolates circulating during 2013–2015, suggesting that field PED viruses (PEDVs) are evolving continuously. Experiments in animals showed that the antisera from guinea pigs immunized with the vaccine strain resulted in higher levels (5 log2) of neutralizing antibodies against the homologous strain and a relatively moderate level of neutralizing antibodies against the field isolates. This finding would be helpful in selecting a PEDV strain for vaccine development.