Length variations in the NA stalk of an H7N1 influenza virus have opposite effects on viral excretion in chickens and ducks.
A deletion of ∼20 amino acids in the stalk of neuraminidase is frequently observed upon transmission of influenza A viruses from waterfowl to domestic poultry. A pair of recombinant H7N1 viruses bearing either a short- or long-stalk neuraminidase was genetically engineered. Inoculation of the long-stalk-neuraminidase virus resulted in a higher cloacal excretion in ducks and led conversely to lower-level oropharyngeal excretion in chickens, associated with a higher-level local immune response and better survival. Therefore, a short-stalk neuraminidase is a determinant of viral adaptation and virulence in chickens but is detrimental to virus replication and shedding in ducks.
Equipe BioVA, INRA UR1282, Infectiologie Animale et Santé Publique, IASP, 37380 Nouzilly, France.
T W
TW
Hoffmann
S
S
Munier
T
T
Larcher
D
D
Soubieux
M
M
Ledevin
E
E
Esnault
A
A
Tourdes
G
G
Croville
J-L
JL
Guérin
P
P
Quéré
R
R
Volmer
N
N
Naffakh
D
D
Marc
D000818:Animals; D002645:Chickens; D004372:Ducks; D057916:Influenza A Virus, H7N1 Subtype / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D005585:Influenza in Birds / Q000821:virology*; D009439:Neuraminidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication; D017201:Virus Shedding
D014764:Viral Proteins; C487630:NA protein, influenza A virus; D009439:Neuraminidase