Virucidal effect of monogalactosyl diacylglyceride from a green microalga, <i>Coccomyxa</i> sp. KJ, against clinical isolates of SARS‐CoV‐2 as assessed by a plaque assay
Kyoko Hayashi, Satomi Asai, Kazuo Umezawa, Hidehumi Kakizoe, Hayato Miyachi, Masanobu Morita, Takaaki Akaike, Hitoshi Kuno, Satoko Komatsu, Takumi Watanabe, Toshio Kawahara
Abstract
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and is capable of human-to-human transmission and rapid global spread. Thus, the establishment of high-quality viral detection and quantification methods, and the development of anti-SARS-CoV-2 agents are critical. METHODS: Here, we present the rapid detection of infectious SARS-CoV-2 particles using a plaque assay with 0.5% agarose-ME (Medium Electroosmosis) as an overlay medium. RESULTS: The plaques were capable of detecting the virus within 36-40 h post-infection. In addition, we showed that a monogalactosyl diacylglyceride isolated from a microalga (Coccomyxa sp. KJ) could inactivate the clinical isolates of SARS-CoV-2 in a time- and concentration-dependent manner. CONCLUSIONS: These results would allow rapid quantification of the infectious virus titers and help develop more potent virucidal agents against SARS-CoV-2.