Submitted to: International Symposium on Avian Influenza
Publication Type: Abstract Only
Publication Acceptance Date: 1/28/2009
Publication Date: 4/5/2009
Citation: Kapczynski, D.R., Tilley, B., Gonder, E., Smith, C., Jackson, S., Liljebjelke, K.A., Petkov, D. 2009. Differences in sialic acid repertoire provides a molecular platform for replication of both avian and mammalian influenza viruses in turkeys but not chickens [abstract]. 7th International Avian Influenza Symposium, April 5-8, 2009, Athens, Georgia. p. 87.
Technical Abstract: Avian influenza virus infection in turkeys results in clinical signs ranging from asymptomatic to severe. Symptoms may include respiratory disease, drop in egg production, reduced hatchability, eggshell abnormalities, decreased feed efficiency, and increased mortality. In 2003, an H3N2 subtype of influenza triple reassortant containing human, swine, and avian gene segments, was isolated from turkey breeders in North Carolina housed in close proximity to a swine operation. This flock experienced a severe drop in egg production, egg quality, and hatchability with no other clinical signs. Subsequently, additional turkey breeder flocks from areas of concentrated swine production in North Carolina, Ohio, Minnesota, Indiana, Missouri, and Canada were infected with the H3N2 subtype of influenza, which was phylogenetically related to swine influenza viruses. Influenza isolates containing mammalian-origin hemagglutinin proteins preferentially bind sialic acid alpha2,6-galactose linked receptors, while avian-origin hemagglutinin proteins bind sialic acid alph2,3-galactose. The objectives of this research was to determine if turkeys contained the receptors needed to support binding by avian and mammalian influenza viruses. Results indicate turkey ovaries exhibited strong reactions for sialic acid alpha2,3gal and sialic acid alph2,6gal linked receptors, while chicken ovaries only showed strong reactions for sialic acid alpha2,3gal. Because these H3N2 turkey isolates contain a mammalian-origin hemagglutinin, the presence of the sialic acid alpha2,6gal linked receptors in turkey ovaries provides the molecular platform for attachment and infection. This finding also implicates turkeys as a potential mixing vessel for generating influenza reassortants of mammalian and avian origin in the field.