title: H4N8 subtype avian influenza virus isolated from shorebirds contains a unique PB1 gene and causes severe respiratory disease in mice.
abstract: H4N8 subtype avian influenza viruses were isolated from shorebirds in eastern Hokkaido. All the isolates shared >99.7% nucleotide homology, and all the viral genes except for PB1 were highly related to those of A/red-necked stint/Australia/1/04. Thus, the isolates were regarded as PB1 reassortants. The most similar PB1 gene was identified in A/mallard/New Zealand/1615-17/04 (H4N6) with nucleotide homology of 90.9%. BALB/c mice intranasally inoculated with the H4N8 isolates developed severe respiratory disease, which eventually led to death in some mice. The virus was isolated from the lungs, and viral antigen was detected in the lungs with pneumonia. Other H4 subtype viruses tested did not cause any symptoms in mice, although these viruses were also isolated from the lungs. The PB2 gene of the H4N8 isolates contains K482R, but not the E627K or D701N substitutions. The PB1-F2 gene of the isolates consists of a 101-amino acid unique sequence, but lacks the N66S mutation.
authors.affiliation: Research Center for Animal Hygiene and Food Safety, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Vuong N
authors.initials: VN
authors.lastname: Bui
authors.forename: Haruko
authors.initials: H
authors.lastname: Ogawa
authors.lastname: Xininigen
authors.forename: Kazuji
authors.initials: K
authors.lastname: Karibe
authors.forename: Kengo
authors.initials: K
authors.lastname: Matsuo
authors.forename: Sanaa S A
authors.initials: SS
authors.lastname: Awad
authors.forename: Germaine L
authors.initials: GL
authors.lastname: Minoungou
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoden
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Haneda
authors.forename: Lai H
authors.initials: LH
authors.lastname: Ngo
authors.forename: Shio
authors.initials: S
authors.lastname: Tamaki
authors.forename: Yu
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Kikuyasu
authors.initials: K
authors.lastname: Nakamura
authors.forename: Keisuke
authors.initials: K
authors.lastname: Saito
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Jonathan
authors.initials: J
authors.lastname: Runstadler
authors.forename: Falk
authors.initials: F
authors.lastname: Huettmann
authors.forename: Falk
authors.initials: F
authors.lastname: Huettman
authors.forename: George M
authors.initials: GM
authors.lastname: Happ
authors.forename: Kunitoshi
authors.initials: K
authors.lastname: Imai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000835:Animals, Wild / Q000821:virology; D001717:Birds / Q000821:virology*; D002460:Cell Line; D005243:Feces / Q000821:virology; D005260:Female; D006801:Humans; D009980:Influenza A virus / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification / Q000472:pathogenicity*; D007251:Influenza, Human / Q000821:virology*; D007564:Japan; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010802:Phylogeny; D012141:Respiratory Tract Infections / Q000821:virology*; D016415:Sequence Alignment; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
chemical_list: D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1