title: Detection and molecular characterization of porcine type 3 orthoreoviruses circulating in South Korea.
abstract: Orthoreoviruses infect virtually all mammalian species, causing systemic infections including mild gastrointestinal and respiratory illnesses. However, little is known about the prevalence or genetic diversity of porcine orthoreoviruses in South Korea. We examined 237 diarrheic fecal samples collected from 78 pig farms around the country. RT-PCR utilizing primers specific for the L1 gene of mammalian orthoreoviruses showed that 45 (19.0%) samples were positive. The 10 strains isolated from orthoreovirus-positive samples formed typical perinuclear cytoplasmic inclusion bodies and had an atypical hemagglutination pattern; these are characteristics of type 3 orthoreovirus. Phylogenetic analysis of the S1 gene in these 10 Korean and other strains showed that type 3 orthoreoviruses could be divided into four lineages; the 10 Korean strains were included in porcine lineage IV, along with T3/porcine/Sichuan/2006. Sequence analysis showed that strains in lineage IV had nucleotide identities of 97.0-98.1% and deduced amino acid identities of 96.4-98.2%. Sequence analysis of the σ1 protein, a viral attachment protein, revealed that the amino acid sequences associated with neurotropism (amino acids 198-204, 249I, 350D, and 419E) were highly conserved among the Korean strains, confirming that neural tropism was present. In conclusion, our findings suggest that porcine orthoreovirus infections are endemic in pig farms in South Korea and that the 10 novel Korean porcine orthoreoviruses belong to porcine lineage IV of type 3 orthoreovirus. In addition, sequence analysis of S1 genes encoding the σ1 protein showed that the 9 of 10 Korean porcine orthoreoviruses exhibited neural tropism.
authors.affiliation: Infection Control Material Research Center and AI Control Material Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185, Republic of Korea.
authors.forename: Hyung-Jun
authors.initials: HJ
authors.lastname: Kwon
authors.forename: Ha-Hyun
authors.initials: HH
authors.lastname: Kim
authors.forename: Hyun-Jeong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jun-Gyu
authors.initials: JG
authors.lastname: Park
authors.forename: Kyu-Yeol
authors.initials: KY
authors.lastname: Son
authors.forename: Juyeon
authors.initials: J
authors.lastname: Jung
authors.forename: Woo Song
authors.initials: WS
authors.lastname: Lee
authors.forename: Kyoung-Oh
authors.initials: KO
authors.lastname: Cho
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Park
authors.forename: Mun-Il
authors.initials: MI
authors.lastname: Kang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005243:Feces / Q000821:virology; D014644:Genetic Variation; D006385:Hemagglutination Inhibition Tests; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D018165:Orthoreovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny; D012088:Reoviridae Infections / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D056910:Republic of Korea; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary*; D017422:Sequence Analysis, DNA; D013552:Swine / Q000821:virology*; D013553:Swine Diseases / Q000175:diagnosis / Q000821:virology*