title: Isolation and Characterization of Dromedary Camel Coronavirus UAE-HKU23 from Dromedaries of the Middle East: Minimal Serological Cross-Reactivity between MERS Coronavirus and Dromedary Camel Coronavirus UAE-HKU23.
abstract: Recently, we reported the discovery of a dromedary camel coronavirus UAE-HKU23 (DcCoV UAE-HKU23) from dromedaries in the Middle East. In this study, DcCoV UAE-HKU23 was successfully isolated in two of the 14 dromedary fecal samples using HRT-18G cells, with cytopathic effects observed five days after inoculation. Northern blot analysis revealed at least seven distinct RNA species, corresponding to predicted subgenomic mRNAs and confirming the core sequence of transcription regulatory sequence motifs as 5'-UCUAAAC-3' as we predicted previously. Antibodies against DcCoV UAE-HKU23 were detected in 58 (98.3%) and 59 (100%) of the 59 dromedary sera by immunofluorescence and neutralization antibody tests, respectively. There was significant correlation between the antibody titers determined by immunofluorescence and neutralization assays (Pearson coefficient = 0.525, p < 0.0001). Immunization of mice using recombinant N proteins of DcCoV UAE-HKU23 and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively, and heat-inactivated DcCoV UAE-HKU23 showed minimal cross-antigenicity between DcCoV UAE-HKU23 and MERS-CoV by Western blot and neutralization antibody assays. Codon usage and genetic distance analysis of RdRp, S and N genes showed that the 14 strains of DcCoV UAE-HKU23 formed a distinct cluster, separated from those of other closely related members of Betacoronavirus 1, including alpaca CoV, confirming that DcCoV UAE-HKU23 is a novel member of Betacoronavirus 1.
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, the University of Hong Kong, Pokfulam, Hong Kong. pcywoo@hku.hk.|Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. pcywoo@hku.hk.|Research Centre of Infection and Immunology, the University of Hong Kong, Pokfulam, Hong Kong. pcywoo@hku.hk.|Carol Yu Centre for Infection, the University of Hong Kong, Pokfulam, Hong Kong. pcywoo@hku.hk.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310006, China. pcywoo@hku.hk.
authors.forename: Patrick C Y
authors.initials: PC
authors.lastname: Woo
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, the University of Hong Kong, Pokfulam, Hong Kong. skplau@hku.hk.|Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. skplau@hku.hk.|Research Centre of Infection and Immunology, the University of Hong Kong, Pokfulam, Hong Kong. skplau@hku.hk.|Carol Yu Centre for Infection, the University of Hong Kong, Pokfulam, Hong Kong. skplau@hku.hk.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310006, China. skplau@hku.hk.
authors.forename: Susanna K P
authors.initials: SK
authors.lastname: Lau
authors.affiliation: Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. rachelfyy2004@yahoo.com.hk.
authors.forename: Rachel Y Y
authors.initials: RY
authors.lastname: Fan
authors.affiliation: Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. candylaucy@gmail.com.
authors.forename: Candy C Y
authors.initials: CC
authors.lastname: Lau
authors.affiliation: Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. emilyhk2811@gmail.com.
authors.forename: Emily Y M
authors.initials: EY
authors.lastname: Wong
authors.affiliation: Central Veterinary Research Laboratory, Dubai, UAE. sjoseph@cvrl.ae.
authors.forename: Sunitha
authors.initials: S
authors.lastname: Joseph
authors.affiliation: Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. alantsangmb@gmail.com.
authors.forename: Alan K L
authors.initials: AK
authors.lastname: Tsang
authors.affiliation: Central Veterinary Research Laboratory, Dubai, UAE. wernery@cvrl.ae.
authors.forename: Renate
authors.initials: R
authors.lastname: Wernery
authors.affiliation: Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. cyrilyip@gmail.com.
authors.forename: Cyril C Y
authors.initials: CC
authors.lastname: Yip
authors.affiliation: Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. microbioct@connect.hku.hk.
authors.forename: Chi-Ching
authors.initials: CC
authors.lastname: Tsang
authors.affiliation: Central Veterinary Research Laboratory, Dubai, UAE. cvrl@cvrl.ae.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wernery
authors.affiliation: State Key Laboratory of Emerging Infectious Diseases, the University of Hong Kong, Pokfulam, Hong Kong. kyyuen@hku.hk.|Department of Microbiology, the University of Hong Kong, Pokfulam, Hong Kong. kyyuen@hku.hk.|Research Centre of Infection and Immunology, the University of Hong Kong, Pokfulam, Hong Kong. kyyuen@hku.hk.|Carol Yu Centre for Infection, the University of Hong Kong, Pokfulam, Hong Kong. kyyuen@hku.hk.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310006, China. kyyuen@hku.hk.
authors.forename: Kwok-Yung
authors.initials: KY
authors.lastname: Yuen
mesh_terms: D000818:Animals; D002162:Camelus / Q000821:virology*; D045744:Cell Line, Tumor; D003429:Cross Reactions; D005814:Genes, Viral; D006801:Humans; D051379:Mice; D065207:Middle East Respiratory Syndrome Coronavirus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D010802:Phylogeny
keywords: characterization; coronavirus; dromedary camel; isolation