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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Exotic & Emerging Avian Viral Diseases Research » Research » Publications at this Location » Publication #420766
Research Project: Control Strategies to Prevent and Respond to Diseases Outbreaks Caused by Avian Influenza Viruses

Location: Exotic & Emerging Avian Viral Diseases Research

Title: In silico genomic analysis of avian influenza viruses isolated from marine seal colonies

Author
item CHRZASTEK, KLAUDIA - Georgia State University
item Kapczynski, Darrell

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2024
Publication Date: 12/16/2024
Citation: Chrzastek, K., Kapczynski, D.R. 2024. In silico genomic analysis of avian influenza viruses isolated from marine seal colonies. Pathogens. 13(11):1009. https://doi.org/10.3390/pathogens13111009.
DOI: https://doi.org/10.3390/pathogens13111009

Interpretive Summary: Avian influenza is caused by infection with avian influenza virus (AIV). These viruses are naturally found in wild aquatic birds and can infect domestic poultry causing significant mortality and financial losses. AIVs do not normally infect mammals, however, recent outbreaks have demonstrated the ability to jump into marine mammals. In these studies, we perform analysis of AIV from marine seal populations. We demonstrate that isolation of AIV have increased in marine mammalian species. We also demonstrate that genetic changes usually occurs in isolates from marine seals. Taken together, these studies broaden our understanding of AIV adaption in other species.

Technical Abstract: Genetically diverse avian influenza viruses (AIV) are maintained in wild aquatic birds with increasingly frequent spillover into mammals, yet these represent a small proportion of the overall detections. The isolation of AIV in marine mammals, including seals, has been reported sporadically throughout the last 45 years. Prior to 2016, all reports of AIVs detected from seals were of low pathogenicity AIV (LPAIV). In spite of this, a majority of reported AIV outbreaks caused fatal respiratory diseases, with harbor seals particularly susceptible to infection. The H5 clade 2.3.4.4b highly pathogenic AIV (HPAIV) was detected in seals for the first time in 2016-2017. Globally, many cases of mass seal die-offs have occurred from 2.3.4.4b HPAIV and are attributed to spillover from wild bird species. The potential of seal-to-seal transmission has been considered after massive mortality of southern Elephant seals off the Argentina coast. Close contact between seals and wild birds, the rapid evolution of H5N1 AIVs, and the possibility of efficient mammal-to-mammal transmission, are increasing concerns over the potential for the establishment of a marine mammal reservoir, and public health risks associated with pandemic potential of the virus. This manuscript details the detection of AIV in the seal population, demonstrating interesting features of different subtypes with emphasis on avian-to-mammal-to-mammal transmission. Phylogenetic characterization of the representative seal isolates was performed to demonstrate the relationships within the different virus isolates. Furthermore, we demonstrate that the reassortment events between different LPAIVs occurred before and after the viruses reached the seal population. The reassortment of viral segments plays an important role in the evolution of influenza viruses. Taken together, these data provide information on the impact and isolation of AIV in seal populations.