Abstract
Wild aquatic birds are the major reservoir of influenza A virus. Cloacal swabs and feces samples (n = 6595) were collected from 62 bird species in Argentina from 2006 to 2016 and screened for influenza A virus. Full genome sequencing of 15 influenza isolates from 6 waterfowl species revealed subtypes combinations that were previously described in South America (H1N1, H4N2, H4N6 (n = 3), H5N3, H6N2 (n = 4), and H10N7 (n = 2)), and new ones not previously identified in the region (H4N8, H7N7 and H7N9). Notably, the internal gene segments of all 15 Argentine isolates belonged to the South American lineage, showing a divergent evolution of these viruses in the Southern Hemisphere. Time-scaled phylogenies indicated that South American gene segments diverged between ~ 30 and ~ 140 years ago from the most closely related influenza lineages, which include the avian North American (PB1, HA, NA, MP, and NS-B) and Eurasian lineage (PB2), and the equine H3N8 lineage (PA, NP, and NS-A). Phylogenetic analyses of the hemagglutinin and neuraminidase gene segments of the H4, H6, and N8 subtypes revealed recent introductions and reassortment between viruses from the Northern and Southern Hemispheres in the Americas. Remarkably and despite evidence of recent hemagglutinin and neuraminidase subtype introductions, the phylogenetic composition of internal gene constellation of these influenza A viruses has remained unchanged. Considering the extended time and the number of sampled species of the current study, and the paucity of previously available data, our results contribute to a better understanding of the ecology and evolution of influenza virus in South America.
Highlights
IntroductionIntroduction Influenza AViruses (IAVs) belong to the familyOrthomyxoviridae. The genome of Influenza AViruses (IAVs) is composed of 8 segments of negative-sense, single-stranded RNA
Introduction Influenza AViruses (IAVs) belong to the familyOrthomyxoviridae
Viable Influenza AViruses (IAVs) were isolated from twenty-two RT-qPCR positive samples representing seven different bird species (Fig. 2), including Anas versicolor, Netta peposaca, Anas cyanoptera, Anas flavirostris, Anas georgica, Sarkidiornis melanotos and Larus dominicanus
Summary
Introduction Influenza AViruses (IAVs) belong to the familyOrthomyxoviridae. The genome of IAVs is composed of 8 segments of negative-sense, single-stranded RNA. The genome of IAVs is composed of 8 segments of negative-sense, single-stranded RNA. Wild aquatic birds of the order Anseriformes and Charadriiformes are considered the natural hosts of IAVs. Based on the antigenic characteristics of their surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA), IAVs are divided into subtypes. 16 HA subtypes (H1 to H16) and 9 NA subtypes (N1 to N9) have been recognized in wild birds. Due to the segmented nature of their genomes, IAVs frequently exchange gene segments, which has led to the identification of many subtype combinations in waterfowl species[1]. Regardless of the subtype, IAV infections in wild aquatic birds occur mostly in the intestinal tract in an apparently asymptomatic fashion. The virus is excreted in large amounts in the feces, which allows for an efficient fecal-oral route mode of transmission among birds
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
