Genome characterisation of the newly discovered avian influenza A H5N7 virus subtype combination.
In Denmark, in 2003, a previously unknown subtype combination of avian influenza A virus, H5N7 (A/Mallard/Denmark/64650/03), was isolated from a flock of 12,000 mallards. The H5N7 subtype combination might be a reassortant between recent European avian influenza A H5, H7, and a third subtype, possibly an H6. The haemagglutinin and the acidic polymerase genes of the virus were closely related to a low-pathogenic Danish H5N2 virus A/Duck/Denmark/65041/04 (H5N2). The neuraminidase gene and the non-structural gene were most similar to the highly pathogenic A/Chicken/Netherlands/1/03 (H7N7) and the human-fatal A/Netherlands/219/03 (H7N7), respectively. The basic polymerase 1 and 2 genes were phylogenetically equidistant to both A/Duck/Denmark/65047/04 (H5N2) and A/Chicken/Netherlands/1/03 (H7N7). The nucleoprotein and matrix gene had highest nucleotide sequence similarity to the H6 subtypes A/Duck/Hong Kong/3096/99 (H6N2) and A/WDk/ST/1737/2000 (H6N8), respectively. All genes of the H5N7 strain were of avian origin, and no further evidence of pathogenicity to humans has been found.
Bragstad
K
K
Department of Virology, Statens Serum Institut, Copenhagen, Denmark.
Jørgensen
P H
PH
Handberg
K J
KJ
Fomsgaard
A
A
D000818:Animals; D004372:Ducks / Q000821:virology; D016679:Genome, Viral; D009980:Influenza A virus / Q000145:classification / Q000235:genetics*; D005585:Influenza in Birds / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012367:RNA, Viral