Molecular characterization of low pathogenicity H7N3 avian influenza viruses isolated in Italy.
The complete coding regions of the surface glycoproteins, nucleoprotein (NP), polymerase 2 (PB2), and matrix (M) of A/turkey/214845/02 and A/turkey/220158/99 (H7N3) low pathogenicity avian influenza (LPAI) viruses isolated in October 2002 in Italy were amplified and sequenced to determine the epidemiologic relationships with an A/turkey/Italy/4603/99 (H7N1/4603/99) LPAI virus isolated during the 1999-2001 epizootic in Italy. The hemagglutinin (HA) of H7N3 viruses showed 97.8% nucleotide similarity with A/turkey/Italy/4603/99 (H7N1), and NP, M, and PB2 gene similarities were 93.6%, 98.2%, and 96.2%, respectively. Phylogenetic analyses of HA, PB2, and M genes showed that H7N3 and H7N1 viruses were closely related. Sequence analysis revealed a 23 amino acid deletion in the stalk of the neuraminidase of H7N3 viruses and a unique deletion of amino acid glycine in position 17 in the NP gene of H7N1 virus.
Di Trani
L
L
Department of Food and Animal Health, Istituto Supieriore di Sanità, Rome, 00161, Italy.
Bedini
B
B
Cordioli
P
P
Muscillo
M
M
Vignolo
E
E
Moreno
A
A
Tollis
M
M
D000818:Animals; D004196:Disease Outbreaks / Q000662:veterinary*; D005814:Genes, Viral / Q000235:genetics*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D009980:Influenza A virus / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D005585:Influenza in Birds / Q000453:epidemiology* / Q000821:virology; D007558:Italy / Q000453:epidemiology; D008562:Membrane Glycoproteins / Q000235:genetics; D008967:Molecular Biology; D009439:Neuraminidase; D009698:Nucleoproteins / Q000235:genetics; D016366:Open Reading Frames; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000453:epidemiology* / Q000821:virology; D014422:Turkeys / Q000821:virology*
D019267:Hemagglutinin Glycoproteins, Influenza Virus; D008562:Membrane Glycoproteins; D009698:Nucleoproteins; D009439:Neuraminidase