Isolation and characterization of mammalian orthoreovirus from bats in the United States

Abstract

Mammalian orthoreovirus (MRV) infects many mammalian species including humans, bats, and domestic animals. To determine the prevalence of MRV in bats in the United States, we screened more than 900 bats of different species collected during 2015–2019 by a real‐time reverse‐transcription polymerase chain reaction assay; 4.4% bats tested MRV‐positive and 13 MRVs were isolated. Sequence and phylogenetic analysis revealed that these isolates belonged to four different strains/genotypes of viruses in Serotypes 1 or 2, which contain genes similar to those of MRVs detected in humans, bats, bovine, and deer. Further characterization showed that these four MRV strains replicated efficiently on human, canine, monkey, ferret, and swine cell lines. The 40/Bat/USA/2018 strain belonging to the Serotype 1 demonstrated the ability to infect and transmit in pigs without prior adaptation. Taken together, this is evidence for different genotypes and serotypes of MRVs circulating in US bats, which can be a mixing vessel of MRVs that may spread to other species, including humans, resulting in cross‐species infections.

Genetic characterization and pathogenicity in a mouse model of newly isolated bat-originated mammalian orthoreovirus in South Korea

“…Recently, the diversity of bat viruses has been of interest to many studies because of the high prevalence of disease-related viral families in bats, such as Coronaviridae, Paramyxoviridae , and Rhabdoviridae ( 23 , 45 , 46 ). Circulating MRVs in bat populations have been reported in many countries on different continents ( 30 , 32 , 37 , 47 ), suggesting pervasive dissemination. Demonstration of serious infections in humans, mice, and swine with bat-borne reoviruses indicates that bats are important intermediate hosts of these viruses ( 23 , 24 , 38 ).…”

“…Bat MRVs have been shown to exhibit a broad range of cell susceptibility ( 6 , 33 , 47 ). In this study, the collected strain was examined for potential infectivity in different cell lines from different organs, such as the kidney, lung, intestine, cervix, and bone, from a variety of hosts, including humans, non-human primates, and pigs.…”

“…S2). Several cell lines, such as MDCK, Vero, Marc145, and PK15, are normally used for isolation of MRVs using media supplemented with either FBS or trypsin ( 6 , 37 , 47 , 57 ). Therefore, we compared the growth kinetics of our strain in each cell line in different media.…”

“…MRVs have been previously reported to cause gastrointestinal and respiratory problems in experimental animals ( 7 , 33 , 47 ). Natural infections caused by MRVs include aerosol and/or oral transmission.…”