title: Influenza A virus subtypes in wild birds in North-Eastern Spain (Catalonia).
abstract: Since the spread of H5N1 highly pathogenic avian influenza virus in 2005, many surveillance programmes have been initiated in poultry and wild birds worldwide. This study describes for the first time the detection of different subtypes of avian influenza viruses (AIV) in wild birds in the West Mediterranean area (Catalonia, North-Eastern Spain). During a 3-year period (from mid-2006 to mid-2009), 1374 birds from 16 different families were examined, and a total of 62 AIV were detected by means of a real-time reverse transcriptase PCR assay. AIV were more frequently detected in Anatidae, Phoenicopteridae, Rallidae and Laridae families. Of the 62 positive samples, 28 AIV could be isolated in embryonated eggs. All isolates were subtyped by haemagglutinin and neuraminidase inhibition techniques and 10 different haemagglutinins (HA) and 7 neuraminidases (NA) were found in 13 different subtype combinations. The most common combinations were H4N6 (22.2%) and H1N1 (18.5%). The HA and NA gene sequences of different AIV subtypes were compared and aligned with those available AIV strains from genome databases. Our studies on AIV phylogenetic analysis revealed that all AIV genes sequenced from wild birds in North-Eastern Spain clustered within Eurasian avian clades, including the sequences of H8, N4 and N5 genes analyzed for the first time in Europe. The results contribute to the understanding of AIV in the Mediterranean area and in Europe.
authors.affiliation: Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. nuria.busquets@cresa.uab.es
authors.forename: Núria
authors.initials: N
authors.lastname: Busquets
authors.forename: Anna
authors.initials: A
authors.lastname: Alba
authors.forename: Sebastián
authors.initials: S
authors.lastname: Napp
authors.forename: Azucena
authors.initials: A
authors.lastname: Sánchez
authors.forename: Erika
authors.initials: E
authors.lastname: Serrano
authors.forename: Raquel
authors.initials: R
authors.lastname: Rivas
authors.forename: José I
authors.initials: JI
authors.lastname: Núñez
authors.forename: Natàlia
authors.initials: N
authors.lastname: Majó
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology* / Q000821:virology*; D001717:Birds; D002642:Chick Embryo; D016000:Cluster Analysis; D006385:Hemagglutination Inhibition Tests; D006389:Hemagglutinins, Viral / Q000276:immunology; D009980:Influenza A virus / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000276:immunology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012703:Serotyping; D013030:Spain / Q000453:epidemiology; D014764:Viral Proteins / Q000276:immunology
chemical_list: D006389:Hemagglutinins, Viral; D012367:RNA, Viral; D014764:Viral Proteins; C458881:hemagglutinin fusogenic peptide, influenza virus; C487630:NA protein, influenza A virus; D009439:Neuraminidase