Length variations in the NA stalk of an H7N1 influenza virus have opposite effects on viral excretion in chickens and ducks.

T W Hoffmann (1) , S Munier (2) , T Larcher (3) , D Soubieux (1) , M Ledevin (3) , Evelyne Esnault (1) , A Tourdes (2) , G Croville (4) , J-L Guérin (5) , R Volmer (5) , N Naffakh (2) , Pascale Quéré (1) , Daniel Marc (1)

1 UMR ISP - Infectiologie et Santé Publique
2 Génétique moléculaire des virus à ARN
3 ONIRIS - École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique
4 IHAP - Interactions hôtes-agents pathogènes [Toulouse]
5 ENVT - Ecole Nationale Vétérinaire de Toulouse

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.

Mots clés: neuraminidase; virus H7N1; pouvoir pathogène; virus influenza

Domaines: Virologie

T W Hoffmann, S Munier, T Larcher, D Soubieux, M Ledevin, et al.. Length variations in the NA stalk of an H7N1 influenza virus have opposite effects on viral excretion in chickens and ducks.. Journal of Virology, 2012, 86 (1), pp.584-8. ⟨10.1128/JVI.05474-11⟩. ⟨hal-01136974⟩