title: Full-genome based molecular characterization of encephalitis-associated bovine astroviruses.
abstract: Novel types of astrovirus have been identified recently in association with neurological disease in cattle. Among those viruses is bovine astrovirus CH13 (BoAstV CH13) that has been identified in Switzerland in a cow with encephalitis. Molecular testing by a combination of reverse transcription (RT-) PCR and in situ hybridization (ISH) indicated that astrovirus infection accounts for around one quarter of viral encephalitis cases of unknown etiology in cattle. Yet, it remained to be explored whether these animals were infected by BoAstV CH13 or other astrovirus species. In the present study we sequenced the entire astrovirus genome in brain tissues of eight RT-PCR and/or ISH positive cattle. Phylogenetic comparison of the genomic RNA and the encoded non-structural and structural proteins revealed that all these astrovirus strains were very similar to BoAstV CH13 as well as to a bovine encephalitis strain reported from the USA (BoAstV NeuroS1), and clearly distinct from other previously reported astroviruses. Conserved 5' and 3' untranslated regions (UTRs) were predicted to display distinct secondary RNA structures, which likely play a role in viral RNA replication and/or protein translation. Based on these data we propose that BoAstV CH13/NeuroS1 represents a new genotype species within the genus Mammastrovirus. The high degree of similarity between the strains and their relative distance to other genotype species suggest that during evolution some astroviruses acquired factors that specifically contribute to neuroinvasion.
authors.affiliation: NeuroCenter, Division of Neurological Sciences, Vetsuisse Faculty, University of Bern,Bremgartenstrasse 109a, CH-3012 Bern, Switzerland. Electronic address: ilias.bouzalas@vetsuisse.unibe.ch.
authors.forename: Ilias G
authors.initials: IG
authors.lastname: Bouzalas
authors.affiliation: Interfaculty Bioinformatics Unit, University of Bern and Swiss Institute of Bioinformatics, Baltzerstrasse 6, CH-3012 Bern, Switzerland. Electronic address: daniel.wuethrich@bioinformatics.unibe.ch.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wüthrich
authors.affiliation: NeuroCenter, Division of Neurological Sciences, Vetsuisse Faculty, University of Bern,Bremgartenstrasse 109a, CH-3012 Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Freiestrasse 1, CH-3012 Bern, Switzerland. Electronic address: senija.selimovic@vetsuisse.unibe.ch.
authors.forename: Senija
authors.initials: S
authors.lastname: Selimovic-Hamza
authors.affiliation: Institute of Genetics, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, CH-3012 Bern, Switzerland. Electronic address: cord.droegemueller@vetsuisse.unibe.ch.
authors.forename: Cord
authors.initials: C
authors.lastname: Drögemüller
authors.affiliation: Interfaculty Bioinformatics Unit, University of Bern and Swiss Institute of Bioinformatics, Baltzerstrasse 6, CH-3012 Bern, Switzerland. Electronic address: remy.bruggmann@bioinfromatics.unibe.ch.
authors.forename: Rémy
authors.initials: R
authors.lastname: Bruggmann
authors.affiliation: NeuroCenter, Division of Neurological Sciences, Vetsuisse Faculty, University of Bern,Bremgartenstrasse 109a, CH-3012 Bern, Switzerland. Electronic address: torsten.seuberlich@vetsuisse.unibe.ch.
authors.forename: Torsten
authors.initials: T
authors.lastname: Seuberlich
mesh_terms: D000818:Animals; D019200:Astroviridae / Q000235:genetics* / Q000472:pathogenicity; D019350:Astroviridae Infections / Q000662:veterinary* / Q000821:virology; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D016679:Genome, Viral; D005838:Genotype; D010802:Phylogeny; D013557:Switzerland
keywords: Astrovirus; Cattle; Encephalitis; Epidemiology; Neurology