title: Molecular analysis of hemagglutinin-1 fragment of avian influenza H5N1 viruses isolated from chicken farms in Indonesia from 2008 to 2010.
abstract: Highly pathogenic avian influenza virus of subtype H5N1 (AIV-H5N1) has been circulating in Indonesia since 2003. To understand the genetic diversity of these viruses, and to predict vaccine efficacy, the hemaglutinin-1 (HA-1) fragment of viruses isolated from chicken farms in Indonesia from 2008 to 2010 was sequenced and analyzed. The effects of these molecular changes were investigated in challenge experiments and HI assays of homologous and heterologous strains. Molecular analysis showed that these AIV-H5N1 isolates had evolved into three distinct sub-lineages from an ancestor circulating since 2003. Although no significant positive selection of residues was detected, 12 negatively selected sites were identified (p<0.05). Moreover, four sites showed evidence of significant episodic diversifying selection. The findings indicated complete protectivity and high HI titers with homologous strains, compared with protectivity ranging from 40 to 100% and lower HI titers with heterologous strains resulting from polymorphisms at antigenic sites. Our findings provide valuable insight into the molecular evolution of AIV and have important implications for vaccine efficacy and future vaccination strategies.
authors.affiliation: Animal Biomedical and Molecular Biology Laboratory, Udayana University, Sesetan-Markisa Street No. 6, Denpasar 80226, Bali, Indonesia. Electronic address: gnmahardika@indosat.net.id.
authors.forename: Gusti N
authors.initials: GN
authors.lastname: Mahardika
authors.affiliation: Research and Development Department, PT. Medion, Babakan Ciparay Street #282, Bandung, Indonesia.
authors.forename: Melina
authors.initials: M
authors.lastname: Jonas
authors.affiliation: Research and Development Department, PT. Medion, Babakan Ciparay Street #282, Bandung, Indonesia.
authors.forename: Theresia
authors.initials: T
authors.lastname: Murwijati
authors.affiliation: Research and Development Department, PT. Medion, Babakan Ciparay Street #282, Bandung, Indonesia.
authors.forename: Nur
authors.initials: N
authors.lastname: Fitria
authors.affiliation: Animal Biomedical and Molecular Biology Laboratory, Udayana University, Sesetan-Markisa Street No. 6, Denpasar 80226, Bali, Indonesia.
authors.forename: I Nyoman
authors.initials: IN
authors.lastname: Suartha
authors.affiliation: Animal Biomedical and Molecular Biology Laboratory, Udayana University, Sesetan-Markisa Street No. 6, Denpasar 80226, Bali, Indonesia.
authors.forename: I Gusti A A
authors.initials: IG
authors.lastname: Suartini
authors.affiliation: Faculty of Veterinary Medicine, Bogor Agricultural University, Bogor, West Java, Indonesia.
authors.forename: I Wayan Teguh
authors.initials: IW
authors.lastname: Wibawan
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002645:Chickens; D056738:Cross Protection; D019143:Evolution, Molecular; D007214:Indonesia; D053124:Influenza A Virus, H5N1 Subtype / Q000145:classification / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D005585:Influenza in Birds / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D037102:Lectins / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014611:Vaccination / Q000662:veterinary; D014765:Viral Vaccines / Q000235:genetics / Q000592:standards
chemical_list: D000914:Antibodies, Viral; D037102:Lectins; D014765:Viral Vaccines; C112408:hemagglutinin I
keywords: Avian influenza virus; Chicken industry; H5N1; Indonesia; Vaccine