Genetic and phylogenetic analysis of the ribonucleoprotein complex genes of H9N2 avian influenza viruses isolated from commercial poultry in Iran

Bashashati, Mohsen; Vasfimarandi, Mahdi; Bozorgmehri Fard, Mohammad Hassan; Hemmatzadeh, Farhid; Sabouri, Fereshteh

doi:10.22059/ijvm.2013.35965

Genetic and phylogenetic analysis of the ribonucleoprotein complex genes of H9N2 avian influenza viruses isolated from commercial poultry in Iran

Authors

Mohsen Bashashati ¹

Mahdi Vasfimarandi ¹

Mohammad Hassan Bozorgmehri Fard ¹

Farhid Hemmatzadeh ²

Fereshteh Sabouri ¹

¹ Department of Poultry Diseases, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

² School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, South Australia, Australia

10.22059/ijvm.2013.35965

Abstract

BACKGROUND: The H9N2 subtype of avian influenza
viruses (AIVs) has been isolated in multiple avian species in
many European, Asian, African and American countries. Since
the first outbreak of H9N2 virus in Iran in 1998, this virus has
widely circulated throughout the country, resulting in major
economic losses in chicken flocks. Several amino acids in the
virus ribonucleoprotein (RNP) complex including the nucleoprotein
(NP) and polymerase (PB2, PB1 and PA) proteins are
associated with host range and virulence. OBJECTIVES: Our aim
was to understand the molecular characterization of RNP
complex proteins of Iranian H9N2 subtype isolates. METHODS:
The full length nucleotide sequences of RNP complex genes of
two strains designated as Ck/IR/ZMT-101/98 and Ck/IR/EBGV-
88/10 were amplified and sequenced. RESULTS: The phylogenetic
analysis revealed that both strains were located in
different sub-lineages. However, based on the genetic similarities,
PB1, PAand NP genes of Ck/IR/EBGV-88/10 strain had a
close relationship with a H7N3 subtype strain, isolated from
Pakistan. Most positions of RNP proteins contained amino acids
typical of avian determinants of host range. The results showed
that the Iranian RNP complex genes have undergone genetic
reassortment. CONCLUSIONS: Continuous AIV monitoring in
poultry industry would help to obtain more information about
genetic variation of H9N2 viruses and possible emergence of
virulent and/or pandemic viruses.

Keywords

Avian influenza virus

H9N2

Poultry

ribonucleoprotein