title: A novel astrovirus from dromedaries in the Middle East.
abstract: The recent emergence of Middle East respiratory syndrome coronavirus from the Middle East and its discovery from dromedary camels has boosted interest in the search for novel viruses in dromedaries. The existence of astroviruses (AstVs) in dromedaries was previously unknown. We describe the discovery of a novel dromedary camel AstV (DcAstV) from dromedaries in Dubai. Among 215 dromedaries, DcAstV was detected in faecal samples of four [three (1.5 %) adult dromedaries and one (8.3 %) dromedary calf] by reverse transcription-PCR. Sequencing of the four DcAstV genomes and phylogenetic analysis showed that the DcAstVs formed a distinct cluster. Although DcAstV was most closely related to a recently characterized porcine AstV 2, their capsid proteins only shared 60-66 % amino acid identity, with a mean amino acid genetic distance of 0.372. Notably, the N-terminal halves of the capsid proteins of DcAstV shared ≤ 85 % amino acid identity, but the C-terminal halves only shared ≤ 49 % amino acid identity compared with the corresponding proteins in other AstVs. A high variation of the genome sequences of DcAstV was also observed, with a mean amino acid genetic distance of 0.214 for ORF2 of the four strains. Recombination analysis revealed a possible recombination event in ORF2 of strain DcAstV-274. The low Ka/Ks ratios (number of non-synonymous substitutions per non-synonymous site to number of synonymous substitutions per synonymous site) of the four ORFs in the DcAstV genomes supported the suggestion that dromedaries are the natural reservoir where AstV is stably evolving. These results suggest that AstV is a novel species of the genus Mamastrovirus in the family Astroviridae. Further studies are important to understand the pathogenic potential of DcAstV.
authors: State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, PR China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, PR China.|Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.|Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, PR China.
authors: Patrick C Y
authors: PCY
authors: Woo
authors: Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, PR China.|Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, PR China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, PR China.|Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.
authors: Susanna K P
authors: SKP
authors: Lau
authors: Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.
authors: Jade L L
authors: JLL
authors: Teng
authors: Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.
authors: Alan K L
authors: AKL
authors: Tsang
authors: Central Veterinary Research Laboratory, Dubai, United Arab Emirates.
authors: Sunitha
authors: S
authors: Joseph
authors: Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.
authors: Jun
authors: J
authors: Xie
authors: Central Veterinary Research Laboratory, Dubai, United Arab Emirates.
authors: Shanty
authors: S
authors: Jose
authors: Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.
authors: Rachel Y Y
authors: RYY
authors: Fan
authors: Central Veterinary Research Laboratory, Dubai, United Arab Emirates.
authors: Ulrich
authors: U
authors: Wernery
authors: Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, PR China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, PR China.|Department of Microbiology, The University of Hong Kong, Hong Kong, PR China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, PR China.
authors: Kwok-Yung
authors: KY
authors: Yuen
mesh_terms: D000818:Animals; D019200:Astroviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D019350:Astroviridae Infections / Q000662:veterinary* / Q000821:virology; D002162:Camelus / Q000821:virology*; D036022:Capsid Proteins / Q000235:genetics; D008877:Middle East; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny
chemical_list: D036022:Capsid Proteins