Complete genome sequence of an H7N3 avian influenza virus isolated from ducks in southern China.
ABSTRACT We report here the complete genomic sequence of an H7N3 avian influenza virus (AIV) isolate, which was obtained from duck in 1996. This is the first report of this subtype of AIV being isolated from duck in Guangdong of Southern China. Genomic sequence and phylogenetic analyses showed that it was highly homologous with the wild bird virus A/ruddy turnstone/Delaware Bay/135/1996 (H7N3) and that all eight genes of this virus belonged to the North America gene pool. The availability of genome sequences is helpful to further investigations of epidemiology and evolution of AIV between waterfowl and wild birds.
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ABSTRACT: Monoclonal antibodies specific for the hemagglutinin (HA) or the neuraminidase (NA) of influenza viruses were used in immunoelectron microscopic studies to determine the distribution of the two surface spikes on the virion. Indirect immunogold staining revealed that the HA is uniformly distributed on the virion while the NA occurs in discrete areas. Crosslinking and low temperature studies argue against redistribution of the HA and NA after antibody attachment and indicate that the NA on influenza virus occurs in patches.Virology 03/1986; 149(1):36-43. · 3.37 Impact Factor
- The Lancet 05/2003; 361(9367):1444. · 39.06 Impact Factor
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ABSTRACT: Influenza A virus reservoirs in animals have provided novel genetic elements leading to the emergence of global pandemics in humans. Most influenza A viruses circulate in waterfowl, but those that infect mammalian hosts are thought to pose the greatest risk for zoonotic spread to humans and the generation of pandemic or panzootic viruses. We have identified an influenza A virus from little yellow-shouldered bats captured at two locations in Guatemala. It is significantly divergent from known influenza A viruses. The HA of the bat virus was estimated to have diverged at roughly the same time as the known subtypes of HA and was designated as H17. The neuraminidase (NA) gene is highly divergent from all known influenza NAs, and the internal genes from the bat virus diverged from those of known influenza A viruses before the estimated divergence of the known influenza A internal gene lineages. Attempts to propagate this virus in cell cultures and chicken embryos were unsuccessful, suggesting distinct requirements compared with known influenza viruses. Despite its divergence from known influenza A viruses, the bat virus is compatible for genetic exchange with human influenza viruses in human cells, suggesting the potential capability for reassortment and contributions to new pandemic or panzootic influenza A viruses.Proceedings of the National Academy of Sciences 02/2012; 109(11):4269-74. · 9.74 Impact Factor
Complete Genome Sequence of an H7N3 Avian Influenza Virus
Isolated from Ducks in Southern China
Peirong Jiao, Liangmeng Wei, Runyu Yuan, Yafen Song, Lan Cao, and Ming Liao
MOA Key Laboratory for Animal Vaccine Development, Key Laboratory of Zoonoses Control and Prevention of Guangdong, College of Veterinary Medicine, South China
Agricultural University, Guangzhou, China
We report here the complete genomic sequence of an H7N3 avian influenza virus (AIV) isolate, which was obtained from
duck in 1996. This is the first report of this subtype of AIV being isolated from duck in Guangdong of Southern China.
Genomic sequence and phylogenetic analyses showed that it was highly homologous with the wild bird virus A/ruddy turn-
stone/Delaware Bay/135/1996 (H7N3) and that all eight genes of this virus belonged to the North America gene pool. The
availability of genome sequences is helpful to further investigations of epidemiology and evolution of AIV between water-
fowl and wild birds.
aminidase (NA) glycoproteins, which are located on the outer
surface of the envelope (5). At present, 17 HA and 9 NA sub-
types have been recognized, and only viruses of H5 and H7
subtypes have been shown to cause highly pathogenic avian
influenza (HPAI) in susceptible species (7, 9, 6). The H7 AIV
caused disease outbreaks in poultry in Europe, North America,
South America, and South Asia and in humans in Europe and
North America (4). In 2003, an epidemic of HPAI A virus sub-
type H7N7 occurred in the Netherlands, the virus was trans-
potential for interspecies transmission. There have been only
limited cases of H7 AIV isolated in China, and the first report
was in 2002 when a routine surveillance was carried out in
poultry in Northern China (4).
In this study, an H7N3 strain, named A/Duck/Guangdong/
1/1996 (H7N3), was first isolated from duck in Guangdong of
sequence with an ABI 3730 genetic analyzer using the Sanger
method, which was based on DNA fragments amplified by PCR
with a previous primer (4). Sequence fragments were assem-
bled using Sequencher 5.0. The complete genome of the strain
consists of eight segments of negative-sense single-stranded
RNA molecules, including PB2, PB1, PA, HA, NP, NA, M, and
NS. The full lengths of each segment are 2,341, 2,341, 2,233,
1,731, 1,565, 1,453, 1,027, and 890 nucleotides, respectively.
The eight genes encode the following proteins with the indi-
NP, 498; NA, 469; M1, 252; M2, 80; NS1, 230; and NS2, 121.
The amino acid sequence at the cleavage site in the HA mole-
cule is PENPKTR2GLF, with the characteristic of low-pathoge-
nicity AIV. An analysis of potential N-glycosylation sites of the
surface proteins indicated that the strain possesses six potential
N-glycosylation sites (positions 30, 46, 141, 421, 493, and 516) in
the HA protein and six (positions 14, 57, 66, 72, 146, and 308)
in the receptor-binding site in the HA protein, findings which
showed that it is avian-origin influenza virus.
vian influenza viruses (AIV) are classified in the family
Orthomyxoviridae, genus Influenzavirus A (1). They are
of this virus belonged to the North America gene pool and were
highly homologous (nucleotide homologies were above 99%)
135/1996 (H7N3). Thus, the virus may be transmitted directly to
ducks from wild birds.
These data are useful for analyses of epidemiology and evolu-
tionary characteristics of AIV between waterfowl and wild birds
and support the idea for more-extensive and long-term AIV sur-
Nucleotide sequence accession numbers. The genome se-
quences of A/Duck/Guangdong/1/1996 (H7N3) have been de-
posited in GenBank under accession numbers JQ988864 to
This work was supported by grants from the Natural Science Foundation
the National Natural Science Foundation of China (no. 31172343),
the Science and Technology Projects of Guangdong Province (no.
University Project of Guangdong Province.
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human conjunctivitis and a fatal case of acute respiratory distress syn-
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Received 29 April 2012 Accepted 30 April 2012
Address correspondence to Ming Liao, firstname.lastname@example.org.
P.J. and L.W. contributed equally to this work.
Copyright © 2012, American Society for Microbiology. All Rights Reserved.
jvi.asm.org Journal of Virology p. 7724–7725July 2012 Volume 86 Number 14
subtype H7N2 isolated from chickens in northern China. Virus Genes
5. Murti KG, Webster RG. 1986. Distribution of hemagglutinin and neur-
aminidase on influenza virions as revealed by immunoelectron micro-
scopy. Virology 149:36–43.
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(ed), Diseases of poultry. Iowa State University Press, Ames, IA.
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