Molecular changes associated with the transmission of avian influenza A H5N1 and H9N2 viruses to humans

Citation
M. Shaw et al., Molecular changes associated with the transmission of avian influenza A H5N1 and H9N2 viruses to humans, J MED VIROL, 66(1), 2002, pp. 107-114
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Clinical Immunolgy & Infectious Disease",Microbiology
Journal title
JOURNAL OF MEDICAL VIROLOGY
ISSN journal
0146-6615 → ACNP
Volume
66
Issue
1
Year of publication
2002
Pages
107 - 114
Database
ISI
SICI code
0146-6615(200201)66:1<107:MCAWTT>2.0.ZU;2-H
Abstract
In order to identify molecular changes associated with the transmission of avian influenza A H5N1 and H9N2 viruses to humans, the internal genes from these viruses were compared to sequences from other avian and human influen za A isolates. Phylogenetically, each of the internal genes of all sixteen of the human H5N1 and both of the H9N2 isolates were closely related to one another and fell into a distinct clade separate from clades formed by the same genes of other avian and human viruses. All six internal genes were mo st closely related to those of avian isolates circulating in Asia, indicati ng that reassortment with human strains had not occurred for any of these 1 8 isolates. Amino acids previously identified as host-specific residues wer e predominantly avian in the human isolates although most of the proteins a lso contained residues observed previously only in sequences of human influ enza viruses. For the majority of the nonglycoprotein genes, three distinct subgroups could be distinguished on bootstrap analyses of the nucleotide s equences, suggesting multiple introductions of avian virus strains capable of infecting humans. The shared nonglycoprotein gene constellations of the human H5N1 and H9N2 isolates and their detection in avian isolates only sin ce 1997 when the first human infections were detected suggest that this par ticular gene combination may confer the ability to infect humans and cause disease. Published 2002 Wiley-Liss, Inc.(dagger)