title: Comparison of in vitro replication features of H7N3 influenza viruses from wild ducks and turkeys: potential implications for interspecies transmission.
abstract: In previous work, it was shown that turkey H7N3 influenza viruses, presumably derived 'in toto' from interspecies transmission of duck viruses in Northern Italy, had only 2 aa differences in haemagglutinin and a few amino acid differences as well as a 23 aa deletion in neuraminidase compared with duck viruses. Here, the replication of these duck and turkey viruses in Madin-Darby canine kidney cells was investigated with respect to virus-cell fusion and viral elution from red blood cells. Duck viruses showed similar receptor-binding properties to turkey viruses but possessed a higher pH of fusion activation than the turkey viruses. Conversely, turkey viruses were not able to elute from red blood cells. These data confirm that neuraminidase-stalk deletion impairs the release of virions from cells and also confirm existence of naturally occurring viruses with different pH fusion activities, raising the possibility that these features may play a role in the evolution of influenza viruses in different hosts.
authors.affiliation: Virology Unit, Department of Public Health, University of Florence, Viale Morgagni 48, I-50134 Firenze, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Giannecchini
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore Sanità, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Campitelli
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore Sanità, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Calzoletti
authors.affiliation: Istituto Nazionale per la Fauna Selvatica, Ozzano Emilia, Bologna, Italy.
authors.forename: Maria Alessandra
authors.initials: MA
authors.lastname: De Marco
authors.affiliation: Virology Unit, Department of Public Health, University of Florence, Viale Morgagni 48, I-50134 Firenze, Italy.
authors.forename: Alberta
authors.initials: A
authors.lastname: Azzi
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore Sanità, Rome, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Donatelli
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000821:virology; D001715:Bird Diseases / Q000635:transmission* / Q000821:virology; D002460:Cell Line; D004372:Ducks; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics*; D009980:Influenza A virus / Q000235:genetics* / Q000472:pathogenicity; D005585:Influenza in Birds / Q000453:epidemiology* / Q000635:transmission* / Q000821:virology; D011201:Poultry Diseases / Q000635:transmission* / Q000821:virology; D014422:Turkeys; D014779:Virus Replication
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus