We isolated a strain of H9N2 avian influenza virus from a quail in southern China in May 2015 and named it A/quail/Guangxi/198Q39/2015. All eight gene segments of the strain were sequenced. Sequence analysis indicated that the amino acid motif of the hemagglutinin cleavage site of this H9N2 virus was RSSR↓GLF, which is a typical characteristic of the low pathogenic avian influenza virus. This s...

objectives the aim of this was to indentify the presence of a/h9n2 virus among different high risk occupational groups, in tehran and qazvin provinces in seasonal outbreak in iran. background in the last decade h9n2 avian influenza viruses had caused outbreaks in poultry in many parts of the world. this subtype could infect other animals such as human and pig. avian h9n2 virus has acquired rece...

Host resistance in Desi and commercial layer breeds was studied in this study. It was evaluated by measuring sensitivity of RBCs to LPAIV induced hemagglutination by using RBCs of two breeds and nine other avian species. Moreover, egg infectious dose 50 (EID50) along with mean death time (MDT) in embryonated eggs, intracerebral pathogenicity in dayold chicks, and intravenous pathogenicity, in f...

Background and Aims: Influenza A virus subtype H9N2 have continued to circulate in domestic poultry farms in Asia since 1998. The virus circulates in live bird markets, missing link in epidemiology of avian influenza. Regarding previous studies on H9N2 viruses of Iran and having no data on this subject in Iranian live bird markets this study was conducted to analyze genetically hemagglutinin pr...

Background and Aims: Avian Influenza (AI) H9N2 subtype was first reported to infect turkeys in the United States in 1966 and has been panzootic in Eurasia. In Iran, the H9N2 virus was first isolated from broiler chickens in 1998 in Ghazvin province and it is the most prevalent subtype of influenza virus in poultry industry in Iran at the present time. Materials and Methods: In this study, we se...

BACKGROUND Vaccines constitute a unique selective pressure, different from natural selection, drives the evolution of influenza virus. In this study, A/Chicken/Shanghai/F/1998 (H9N2) was continually passaged in specific pathogen-free embryonated chicken eggs with or without selective pressures from antibodies induced by homologous maternal antibodies. Genetic mutations, antigenic drift, replica...

Abstract Background and Aims: Vaccination of poultry has a major impact on the prevention and control of avian influenza viruses. Nanobiotechnology techniques provide a new approach for improvement of influenza vaccine efficacy. In this study, efficacy of an inactivated nano-adjuvant vaccine developed based on an endemic H9N2 virus was evaluated in SPF chickens. Materials and Methods: I...

Background and Aims: Avian Influenza (AI) H9N2 subtype was first reported to infect turkeys in the United States in 1966 and has been panzootic in Europe and Asia. The impact of avian influenza caused by H9N2 viruses in Iran is now significantly more severe than in previous years. Methods: Sequence analysis and phylogenetic study of the complete coding region Polymerase A (PA) gene of H9N2 subt...

abstract background and aims: vaccination of poultry has a major impact on the prevention and control of avian influenza viruses. nanobiotechnology techniques provide a new approach for improvement of influenza vaccine efficacy. in this study, efficacy of an inactivated nano-adjuvant vaccine developed based on an endemic h9n2 virus was evaluated in spf chickens. materials and methods: in each t...