Mass spectrometry is a powerful methodology for chemical screening to directly quantify substrates and products of enzymes, but its low throughput has been an issue. Recently, an acoustic liquid-handling apparatus (Echo®) used for rapid nano-dispensing has been coupled to a high-sensitivity mass spectrometer to create the Echo® MS system, and we applied this system to screening of SARS-CoV-2 3CL protease inhibitors. Primary screening of 32,033 chemical samples was completed in 12 hours. Among the hits showing selective, dose-dependent 3CL-inhibitory activity, 8 compounds showed antiviral activity in cell-based assay.
Orthoreoviruses have been indentified in several mammals, however, there is no information about orthoreoviruses in shrews. In this study, we screened wild animals in Zambia, including shrews, rodents, and bats for the detection of orthoreoviruses. Two orthoreovirus RNA genomes were detected from a shrew intestinal-contents (1/24) and a bat colon (1/96) sample by reverse-transcription (RT)-PCR targeting the RNA-dependent RNA polymerase gene of orthoreoviruses. Phylogenetic analyses revealed that each of the identified orthoreoviruses formed a distinct branch among members of the Orthoreovirus genus. This is the first report that shrews are susceptible to orthoreovirus infection. Our results suggest the existence of undiscovered orthoreoviruses in shrews and provide important information about the genetic diversity of orthoreoviruses.