The complete genome sequence of an H1N1 avian influenza virus isolated from

PAULA ALVAREZ; ROSANA MATIELLO; ARIEL PEREDA; LORENA BOADO; ELISA D´AMBROSIO; SEBASTIÁN AGUIRRE; JOSÉ LA TORRE; NORA MATTION

Punta del Este

Congreso; Darwin 200 South American Celebration; 2009

An H1N1 avian influenza (AI) virus was isolated from dead and severely ill red-winged tinamous surroundings of Marcos Paz freshwater lagoons in the province of Buenos Aires. After detection by RT-PCR the virus was successfully isolated in chicken embryonated eggs and denominated A/red-winged tinamou/Argentina/MP1/08 (H1N1). Serological analysis revealed that sera from red-winged tinamous had specific hemagglutination inhibition titers, while sera from other birds from the same area were negative.The eight genomic segments from the virus isolate were sequenced and phylogenetic studies were carried out. Analysis of all eight genes revealed that while the hemagglutinin and neuraminidase genes were related to AI viruses from North America, the other six genes M, NP, NS, PA, PB1, and PB2 were more related to previously South American isolates.Several internal genes from AI viruses previously isolated in Bolivia, Chile and Argentina (in 2001, 2002 and 2006, respectively) have been reported to be genetically divergent from AIVs from other parts of the world and were proposed to represent an unique South American AIV phylogenetic lineage, distinct from North American viruses.Phylogenetic analysis of the red-winged tinamou AI virus isolate support this hypothesis, but also suggest more complex evolutionary features and gene exchange within the region. Although 4 genes of the virus isolate (NP, PA, PB1 and PB2) were located in the same phylogenetic clusters, the NS gene from this virus was found very close to the Chilean AI chicken isolates but very distant from the previous Argentine and Bolivian AIV viruses, whereas the M gene from the Bolivian isolate was found clearly more distant from the previous Argentine and Chilean viruses. Finally, it is interesting that NP and PA genes sequences from all South American strains were found grouped close to those of equine origin.