Sequence analysis of recent H7 avian influenza viruses associated with three different outbreaks in commercial poultry in the United States.
The hemagglutinin (HA) and neuraminidase (NA) genes of H7 avian influenza virus (AIV) isolated between 1994 and 2002 from live-bird markets (LBMs) in the northeastern United States and from three outbreaks in commercial poultry have been characterized. Phylogenetic analysis of the HA and NA genes demonstrates that the isolates from commercial poultry were closely related to the viruses circulating in the LBMs. Also, since 1994, two distinguishing genetic features have appeared in this AIV lineage: a deletion of 17 amino acids in the NA protein stalk region and a deletion of 8 amino acids in the HA1 protein which is putatively in part of the receptor binding site. Furthermore, analysis of the HA cleavage site amino acid sequence, a marker for pathogenicity in chickens and turkeys, shows a progression toward a cleavage site sequence that fulfills the molecular criteria for highly pathogenic AIV.
Spackman
Erica
E
Southeast Poultry Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Athens, Georgia 30605, USA.
Senne
Dennis A
DA
Davison
Sherrill
S
Suarez
David L
DL
D000595:Amino Acid Sequence; D000818:Animals; D004196:Disease Outbreaks; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D009980:Influenza A virus / Q000145:classification / Q000235:genetics*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000235:genetics; D010802:Phylogeny; D011200:Poultry / Q000821:virology; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology; D017422:Sequence Analysis, DNA; D014481:United States / Q000453:epidemiology
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D009439:Neuraminidase