title: Genetic characterization of H5N1 influenza A viruses isolated from zoo tigers in Thailand.
abstract: The H5N1 avian influenza virus outbreak among zoo tigers in mid-October 2004, with 45 animals dead, indicated that the avian influenza virus could cause lethal infection in a large mammalian species apart from humans. In this outbreak investigation, six H5N1 isolates were identified and two isolates (A/Tiger/Thailand/CU-T3/04 and A/Tiger/Thailand/CU-T7/04) were selected for whole genome analysis. Phylogenetic analysis of the 8 gene segments showed that the viruses clustered within the lineage of H5N1 avian isolates from Thailand and Vietnam. The hemagglutinin (HA) gene of the viruses displayed polybasic amino acids at the cleavage site, identical to those of the 2004 H5N1 isolates, which by definition are highly pathogenic avian influenza (HPAI). In addition, sequence analyses revealed that the viruses isolated from tigers harbored few genetic changes compared with the viruses having infected chicken, humans, tigers and a leopard isolated from the early 2004 H5N1 outbreaks. Sequence analyses also showed that the tiger H5N1 isolated in October 2004 was more closely related to the chicken H5N1 isolated in July than that from January. Interestingly, all the 6 tiger H5N1 isolates contained a lysine substitution at position 627 of the PB2 protein similar to the human, but distinct from the original avian isolates.
authors.affiliation: Faculty of Veterinary Science, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand.
authors.forename: Alongkorn
authors.initials: A
authors.lastname: Amonsin
authors.forename: Sunchai
authors.initials: S
authors.lastname: Payungporn
authors.forename: Apiradee
authors.initials: A
authors.lastname: Theamboonlers
authors.forename: Roongroje
authors.initials: R
authors.lastname: Thanawongnuwech
authors.forename: Sanipa
authors.initials: S
authors.lastname: Suradhat
authors.forename: Nuananong
authors.initials: N
authors.lastname: Pariyothorn
authors.forename: Rachod
authors.initials: R
authors.lastname: Tantilertcharoen
authors.forename: Sudarat
authors.initials: S
authors.lastname: Damrongwantanapokin
authors.forename: Chantanee
authors.initials: C
authors.lastname: Buranathai
authors.forename: Arunee
authors.initials: A
authors.lastname: Chaisingh
authors.forename: Thaweesak
authors.initials: T
authors.lastname: Songserm
authors.forename: Yong
authors.initials: Y
authors.lastname: Poovorawan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000836:Animals, Zoo / Q000821:virology*; D004196:Disease Outbreaks / Q000662:veterinary; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology*; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013785:Thailand / Q000453:epidemiology; D046010:Tigers / Q000821:virology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D014764:Viral Proteins