Genetic characterization of avian influenza viruses isolated from waterfowl in southern part of South Korea in 2006

Abstract

Aquatic birds are a reservoir of all known influenza A viruses. Avian influenza viruses have played a major role in the creation of pandemic influenza viruses in humans. In this study, we genetically characterized genes of nine isolates from waterfowl in Eulsukdo, a congregating place for migratory birds on the flyway of migration from Siberia, which is located in the southern part of South Korea. Phylogenic analysis showed that HA and NA genes of isolates belonged to Eurasian lineage, and lineage analysis showed that NS, PB1, PA, NP, and M genes of isolates clustered with Eurasian lineage, and PB2 genes of isolates belonged to North American or Eurasian lineage. Results suggest that the interregional transmission of genes of avian influenza viruses may occur in the migratory birds.

Historical Prevalence and Distribution of Avian Influenza Virus A(H7N9) among Wild Birds

“…In Asia, before this outbreak, an H7N9 strain was sequenced from a wild bird in South Korea that was sampled during 2011 in a migratory bird habitat adjacent to duck farms ( 7 ) and also during 2011 in a sample from a mallard duck of unknown status from Japan. In 2008, the other H7N9 strain sequences collected in Asia were from a wild duck that was sampled in South Korea and from a wild bird sampled in Mongolia.…”

“…Recent phylogenetic analysis indicates that the HA segment of the H7N9 subtype is closely related to a strain that was isolated from domestic ducks in Zhejiang, China, in 2011. The neuraminidase (NA) gene of the H7N9 subtype is closely related to that of a strain that was isolated from wild bird samples in South Korea in a location adjacent to a domestic bird production facility; additionally, 6 internal genes are closely related to those of an A(H9N2) virus isolated from a brambling ( Fringilla montifringilla ) sample during 2012 in Beijing, China ( 7 , 8 ). …”

Genetic evidence of intercontinental movement of avian influenza in a migratory bird: the northern pintail (Anas acuta)

“…Several lines of evidence from recent surveys of LPAI in wild birds have led to speculation that intercontinental transfer of avian influenza viruses from Asia to North America via wild birds is rare (Kilpatrick et al 2006;Krauss et al 2007;Winker et al 2007). These include lack of detection of HP H5N1 in North America, phylogenetic divergence between Asian and North American lineages of LPAI (Ito et al 1995;Widjaja et al 2004), and low levels of reassortment between Asian and North American lineages of LPAI (Marakova et al 1999;Wallensten et al 2005;Krauss et al 2007;Dugan et al 2008;Kim et al 2008). However, most of these studies examined viruses obtained from species that are not transcontinental migrants or from mid-latitude locales of North America, which are far removed from sources of Asian lineages of avian influenza.…”

PB1-F2 Finder: scanning influenza sequences for PB1-F2 encoding RNA segments

“…The second outlier is a CPP from A/shorebird/Korea/S331/2006(H10N9), of length 295 with distance 33. This sequence has a single nucleotide insertion at position 266 in the coding transcript, which causes a frame shift mutation rendering PB1 nonfunctional [9]. These sequences are therefore nonfunctional outliers.…”