title: Phylogenetic analysis of the neuraminidase gene of pandemic H1N1 influenza A virus circulating in the South American region.
abstract: Molecular characterization of circulating influenza A viruses (IAV) in all regions of the world is essential to detect mutations potentially involved in increased virulence, anti-viral resistance and immune escape. In order to gain insight into these matters, a phylogenetic analysis of the neuraminidase (NA) gene of 146 pandemic H1N1 (H1N1pdm) influenza A virus strains isolated in Argentina, Brazil, Chile, Paraguay, Peru and Uruguay from 2009 to 2013 was performed. Comparison of vaccine strain A/California/7/2009 included in the influenza vaccine recommended for the Southern hemisphere from 2010 through 2013 influenza seasons and strains isolated in South America revealed several amino acid substitutions. Mapping of these substitutions revealed that most of them are located at the surface of the protein and do not interfere with the active site. 3.4% of the strains enrolled in these studies carried the H275Y substitution that confers resistance to oseltamivir. Strains isolated in South America differ from vaccine in two predicted B-cell epitope regions present at positions 102-103 and 351-352 of the NA protein. Moreover, vaccine and strains isolated in Paraguay differ also in an epitope present at position 229. These differences among strains isolated in South America and vaccine strain suggests that these epitopes may not be present in strains isolated in this region. A potential new N-linked glycosylation site was observed in the NA protein of an H1N1pdm IAV strain isolated in Brazil. The results of these studies revealed several genetic and antigenic differences in the NA of H1N1pdm IAV among vaccine and strains circulating in South America. All these findings contribute to our understanding of the course of genetic and antigenic evolution of H1N1pdm IAV populations circulating in the South American region and, consequently, contribute to the study and selection of future and more appropriate vaccines and anti-viral drugs.
authors.affiliation: Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay.
authors.forename: Victoria
authors.initials: V
authors.lastname: Comas
authors.affiliation: Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay; Viral Populations and Pathogenesis laboratory. Institut Pasteur, CNRS UMR 3569, Paris, France.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Moratorio
authors.affiliation: Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay.
authors.forename: Martin
authors.initials: M
authors.lastname: Soñora
authors.affiliation: Centro Nacional de Referencia de Influenza, Departamento de Laboratorios de Salud Pública, Ministerio de Salud Pública, Alfredo Navarro 3051 acceso norte, 11200 Montevideo, Uruguay.
authors.forename: Natalia
authors.initials: N
authors.lastname: Goñi
authors.affiliation: Laboratorio de Biología Molecular, Asociación Española Primera de Socorros Mutuos, Br. Artigas 1515, 11300 Montevideo, Uruguay.
authors.forename: Silvana
authors.initials: S
authors.lastname: Pereyra
authors.affiliation: Laboratorio de Biología Molecular, Asociación Española Primera de Socorros Mutuos, Br. Artigas 1515, 11300 Montevideo, Uruguay.
authors.forename: Silvana
authors.initials: S
authors.lastname: Ifran
authors.affiliation: Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay.
authors.forename: Pilar
authors.initials: P
authors.lastname: Moreno
authors.affiliation: Laboratorio de Virología Molecular, Centro de Investigaciones Nucleares, Facultad de Ciencias, Universidad de la República, Igua 4225, 11400 Montevideo, Uruguay. Electronic address: cristina@cin.edu.uy.
authors.forename: Juan
authors.initials: J
authors.lastname: Cristina
mesh_terms: D019943:Amino Acid Substitution; D016000:Cluster Analysis; D024882:Drug Resistance, Viral; D018985:Epitopes, B-Lymphocyte / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008969:Molecular Sequence Data; D009439:Neuraminidase / Q000235:genetics*; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D013020:South America / Q000453:epidemiology; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D018985:Epitopes, B-Lymphocyte; D012367:RNA, Viral; D014764:Viral Proteins; C487630:NA protein, influenza A virus; D009439:Neuraminidase
keywords: Evolution; Influenza A virus; Neuraminidase; Pandemic