Pathogenicity of highly pathogenic avian H5N1 influenza A viruses isolated from humans between 2003 and 2008 in northern Vietnam.
Vietnam is one of the countries most affected by highly pathogenic H5N1 influenza A viruses. To evaluate the potential pathogenicity in mammals of H5N1 viruses isolated from humans in Vietnam, we determined the sequences of all eight genes of 22 human isolates collected between 2003 and 2008 and compared their virulence in mice. The isolates were classified into clade 1 and clade 2.3.4 and differed in pathogenicity for mice. Whilst lysine at position 627 of PB2 (PB2-627K) is a critical virulence determinant for clade 2.3.4 viruses, asparagine at position 701 of PB2 and other unknown virulence determinants appear to be involved in the high pathogenicity of clade 1 viruses, warranting further studies to determine the factors responsible for the high virulence of H5N1 viruses in mammals.
Le
Quynh Mai
QM
National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Vietnam.
Ito
Mutsumi
M
Muramoto
Yukiko
Y
Hoang
Phuong Vu Mai
PV
Vuong
Cuong Duc
CD
Sakai-Tagawa
Yuko
Y
Kiso
Maki
M
Ozawa
Makoto
M
Takano
Ryo
R
Kawaoka
Yoshihiro
Y
D000818:Animals; D001216:Asparagine / Q000235:genetics; D016000:Cluster Analysis; D004195:Disease Models, Animal; D005838:Genotype; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification* / Q000472:pathogenicity*; D007251:Influenza, Human / Q000821:virology*; D008239:Lysine / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009976:Orthomyxoviridae Infections / Q000473:pathology / Q000821:virology; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014744:Vietnam; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics
C057027:PB2 protein, Influenzavirus A; D012367:RNA, Viral; D014764:Viral Proteins; D037521:Virulence Factors; D001216:Asparagine; D012324:RNA-Dependent RNA Polymerase; D008239:Lysine