Characterization of a pathogenic H9N2 influenza A virus isolated from central China in 2007

Abstract

The entire genome of the A/Chicken/Hubei/C1/2007 (H9N2) virus, isolated from central China in 2007, was completely sequenced and phylogenetically analyzed. Phylogenetic analysis demonstrated that A/Chicken/Hubei/C1/2007 (H9N2) virus represents multiple reassortant lineages, with genes coming from the early mainland China strain (Ck/Beijing/1/94), an H9N2 virus with special genotype (Ck/shanghai/F/98) and other lineages from poultry in Asia. Infection studies indicated that A/Chicken/Hubei/C1/2007 (H9N2) virus replicated efficiently in MDCK cells and in BALB/c mice. The H9N2 virus also replicated to high titers in chicken respiratory tracts and caused overt clinical signs in chickens. Our results suggest that attention should be paid to the natural evolution of H9N2 influenza viruses and to the control of H9N2 influenza viruses in animals.

Genetic analysis of polymerase complex (PA, PB1 and PB2) genes of H9N2 avian influenza viruses from Iran (1999 to 2009)

“…This finding suggests a high degree of diversity among the H9N2 viruses in the regions of the Middle East and Indian sub-continent. In recent years, novel genotypes of H9N2 avian influenza viruses from domestic poultry in China, Korea, Vietnam, India and Pakistan have been identified and well characterized [27][28][29][30][31][32][33][34] . In February 2006, highly pathogenic H5N1 virus was isolated from wild birds in Northern provinces of Iran [28] .…”

Sequence and phylogenetic analysis of neuraminidase genes of H9N2 avian influenza viruses isolated from commercial broiler chicken in Iran (2008 and 2009)

“…Sublineage II (Beijing-like) consists of Hong Kong H9N2 viruses isolated in 1997, which were characterized by no amino acid deletion, and all the mainland China H9N2 strains which had three amino acid deletions at positions 63, 64 and 65 except for the primary chicken H9N2 viruses identified in Beijing 1994. Sublineage III (Korean-like) included the Korean strains and viruses isolated from domestic ducks in Hong Kong in 1997 Tosh et al 2008;Wu et al 2008).…”

Isolation and phylogenetic characterization of haemagglutinin and neuraminidase genes of H9N2 low pathogenicity avian influenza virus isolated from commercial layers in India

“…In Asia, H9N2 viruses were regularly isolated from ducks [8][9][10]. However, during the latter half of the last decade, H9N2 viruses had caused disease outbreaks in chicken in many parts of the world including Germany, Italy, Ireland, Iran, Pakistan, Saudi Arabia, South Korea, UAE, Israel, Jordan, China, South Africa and USA [11][12][13][14][15][16][17]. The LPAI H9N2 viruses generally cause decreased egg production and mild to moderate infections, but they can also cause heavy morbidity and mortality when the birds are co-infected with other agents [18,19].…”