title: A highly pathogenic avian-derived influenza virus H5N1 with 2009 pandemic H1N1 internal genes demonstrates increased replication and transmission in pigs.
abstract: This study investigated the pathogenicity and transmissibility of a reverse-genetics-derived highly pathogenic avian influenza (HPAI) H5N1 lineage influenza A virus that was isolated from a human, A/Iraq/755/06. We also examined surface gene reassortant viruses composed of the haemagglutinin and neuraminidase from A/Iraq/755/06 and the internal genes of a 2009 pandemic H1N1 virus, A/New York/18/2009 (2Iraq/06 : 6NY/09 H5N1), and haemagglutinin and neuraminidase from A/New York/18/2009 with the internal genes of A/Iraq/755/06 (2NY/09 : 6Iraq/06 H1N1). The parental A/Iraq/755/06 caused little to no lesions in swine, limited virus replication was observed in the upper respiratory and lower respiratory tracts and transmission was detected in 3/5 direct-contact pigs based on seroconversion, detection of viral RNA or virus isolation. In contrast, the 2Iraq/06 : 6NY/09 H5N1 reassortant caused mild lung lesions, demonstrated sustained virus replication in the upper and lower respiratory tracts and transmitted to all contacts (5/5). The 2NY/09 : 6Iraq/06 H1N1 reassortant also caused mild lung lesions, there was evidence of virus replication in the upper respiratory and lower respiratory tracts and transmission was detected in all contacts (5/5). These studies indicate that an HPAI-derived H5N1 reassortant with pandemic internal genes may be more successful in sustaining infection in swine and that HPAI-derived internal genes were marginally compatible with pandemic 2009 H1N1 surface genes. Comprehensive surveillance in swine is critical to identify a possible emerging HPAI reassortant in all regions with HPAI in wild birds and poultry and H1N1pdm09 in pigs or other susceptible hosts.
authors.affiliation: Virus and Prion Research Unit, USDA, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA.
authors.forename: Eugenio J
authors.initials: EJ
authors.lastname: Abente
authors.affiliation: Present address: Merck Animal Health, De Soto, Kansas, USA.|Virus and Prion Research Unit, USDA, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA.
authors.forename: Pravina
authors.initials: P
authors.lastname: Kitikoon
authors.affiliation: Virus and Prion Research Unit, USDA, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Lager
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Gauger
authors.affiliation: Virus and Prion Research Unit, USDA, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA.
authors.forename: Tavis K
authors.initials: TK
authors.lastname: Anderson
authors.affiliation: Virus and Prion Research Unit, USDA, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Vincent
mesh_terms: D000818:Animals; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D007251:Influenza, Human / Q000821:virology; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000662:veterinary / Q000821:virology; D016865:Reassortant Viruses / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D012137:Respiratory System / Q000473:pathology / Q000821:virology; D059386:Reverse Genetics; D013552:Swine; D013553:Swine Diseases / Q000473:pathology / Q000821:virology; D014779:Virus Replication