First isolation of West Nile virus from a dromedary camel.
Although antibodies against West Nile virus (WNV) have been detected in the sera of dromedaries in the Middle East, North Africa and Spain, no WNV has been isolated or amplified from dromedary or Bactrian camels. In this study, WNV was isolated from Vero cells inoculated with both nasal swab and pooled trachea/lung samples from a dromedary calf in Dubai. Complete-genome sequencing and phylogenetic analysis using the near-whole-genome polyprotein revealed that the virus belonged to lineage 1a. There was no clustering of the present WNV with other WNVs isolated in other parts of the Middle East. Within lineage 1a, the dromedary WNV occupied a unique position, although it was most closely related to other WNVs of cluster 2. Comparative analysis revealed that the putative E protein encoded by the genome possessed the original WNV E protein glycosylation motif NYS at E154-156, which contained the N-linked glycosylation site at N-154 associated with increased WNV pathogenicity and neuroinvasiveness. In the putative NS1 protein, the A70S substitution observed in other cluster 2 WNVs and P250, which has been implicated in neuroinvasiveness, were present. In addition, the foo motif in the putative NS2A protein, which has been implicated in neuroinvasiveness, was detected. Notably, the amino-acid residues at 14 positions in the present dromedary WNV genome differed from those in most of the closely related WNV strains in cluster 2 of lineage 1a, with the majority of these differences observed in the putative E and NS5 proteins. The present study is the first to demonstrate the isolation of WNV from dromedaries. This finding expands the possible reservoirs of WNV and sources of WNV infection.
Central Veterinary Research Laboratory, Dubai, the United Arab Emirates.
Sunitha
S
Joseph
Central Veterinary Research Laboratory, Dubai, the United Arab Emirates.
Ulrich
U
Wernery
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Jade Ll
JL
Teng
Central Veterinary Research Laboratory, Dubai, the United Arab Emirates.
Renate
R
Wernery
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Yi
Y
Huang
Central Veterinary Research Laboratory, Dubai, the United Arab Emirates.
Nissy Ag
NA
Patteril
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Kwok-Hung
KH
Chan
Central Veterinary Research Laboratory, Dubai, the United Arab Emirates.
Shyna K
SK
Elizabeth
Department of Microbiology, The University of Hong Kong, Hong Kong, China.
Rachel Yy
RY
Fan
Department of Microbiology, The University of Hong Kong, Hong Kong, China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.|Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310000, Zhejiang Province, China.
Susanna Kp
SK
Lau
Central Veterinary Research Laboratory, Dubai, the United Arab Emirates.
Jörg
J
Kinne
Department of Microbiology, The University of Hong Kong, Hong Kong, China.|State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China.|Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China.|Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China.|Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou 310000, Zhejiang Province, China.
Patrick Cy
PC
Woo
D000352:Africa, Northern / Q000453:epidemiology; D000818:Animals; D002162:Camelus / Q000821:virology*; D002522:Chlorocebus aethiops; D004197:Disease Reservoirs / Q000662:veterinary*; D016679:Genome, Viral; D006031:Glycosylation; D008168:Lung / Q000821:virology; D008877:Middle East / Q000453:epidemiology; D009666:Nose / Q000821:virology; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014709:Vero Cells; D017361:Viral Nonstructural Proteins / Q000235:genetics; D014901:West Nile Fever / Q000453:epidemiology / Q000662:veterinary*; D014902:West Nile virus / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity
D017361:Viral Nonstructural Proteins; C531936:nonstructural protein 1, West Nile virus