The complete genome sequence of an avian influenza virus isolated from wild terrestrial non migratory birds in Argentina supports the hypothesis of a South American AIV phylogenetic lineage

PAULA ALVAREZ; ROSANA MATTIELLO; ARIEL PEREDA; LORENA BOADO; ELISA D’AMBROSIO; SEBASTIAN AGUIRRE; JOSE LA TORRE; NORA MATTION

Punta del Este (Uruguay)

Congreso; Darwin 200 South American Celebration; 2009

The complete genome sequence of an avian influenza virus isolated from wild terrestrial non migratory birds in Argentina supports the hypothesis of a South American AIV phylogenetic lineage. ALVAREZ PAULA1, MATTIELLO ROSANA2, PEREDA ARIEL3, BOADO LORENA1, D’AMBROSIO ELISA2, AGUIRRE SEBASTIAN1, LA TORRE JOSÉ1, MATTION NORA1. 1 Centro de Virología Animal, Instituto de Ciencia y Tecnología Dr. César Milstein, CONICET, Buenos Aires, Argentina 2 Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Argentina. 3 Instituto Nacional de Tecnología Agropecuaria, Centro de Investigación de Ciencias Veterinarias y Agronómicas (INTA-CICVyA), Argentina. Background: An H1N1 avian influenza (AI) virus was isolated in April 2008 in Argentina from dead and severely ill red-winged tinamous (Ryynchotus rufescens) captured in the 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 South American 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. Given the scarce information available on the subject, the interesting genetic features of the red-winged tinamou AIV analysed here might contribute to the knowledge on the evolution and distribution of AI viruses subtypes circulating in South America.