Since 1998, an epidemic of avian influenza occurred in the Iranian poultry industry. The identified agent was a low-pathogenicity H9N2 avian influenza virus that caused frequent episodes of high mortality in broiler chicken farms in Iran and some other Asian countries. This study was designed to investigate the prevalence of AIV H9N2 subtype in commercial chicken flocks in Dezful, southern Iran...

This study investigated the potential of pinon shell polysaccharide (PSP) to enhance immunity against H9N2 subtype avian influenza virus (H9N2 AIV) in chickens. The effect of PSP treatment and H9N2 virus infection after PSP pretreatment were investigated by [3-(4, 5-dimethylthiazol-2-yl)-2, 3-diphenyl tetrazolium bromide] assay and analysis of major histocompatibility complex and cytokine mRNA ...

During a study on high mortality cases of goose embryo in Shandong Province, China (2014-2015), we isolated an H9N2 avian influenza virus (AIV) strain (A/goose/Shandong/DP01/2014, DP01), which was supposedly the causative agent for goose embryo death. Sequence analysis revealed that DP01 shared 99.9% homology in the HA gene with a classic immune suppression strain SD06. To study the potential v...

Bacterial co-infections can probably influence the pathogenicity of H9N2 low pathogenic avian influenza virus (AIV). This study aimed to evaluate the effect of exposure time to Escherichia coli (O:2) on the pathogenicity of H9N2 AIV in broiler chickens. Three hundred and sixty broiler chickens were randomly allocated to six equal groups. At the age of 26 days, all chicks except groups 5 and 6 w...

Since H9N2 avian influenza virus (AIV) was first isolated in Guangdong province of China, the virus has been circulating in chicken flocks in mainland China. However, a systematic phylogenetic analysis of H9N2 AIV from chickens in Shandong of China has not been conducted. Based on hemagglutinin (HA) gene sequences of H9N2 AIVs isolated from chickens in Shandong of China between 1998 and 2013, g...

Influenza H9N2 subtype viruses and their reassortants (such as H7N9) are posing increasing threats to birds and humans in China. During 2009-2013, multiple novel subtype viruses with H9N2 original genes emerged in China. Yet, the genetic evolution of H9N2 viruses in various host organisms in China has not been systematically investigated since 2009. In the present study, we performed large-scal...

Low pathogenic Avian Influenza (AI) virus has the ability to evolve to high pathogenic viruses resulting in significant economic losses in the poultry sector. This study aims at assessing the impact of H9N2 viral passaging in broilers and its relatedness to pathogenicity and amino acid (a.a) sequences of the hemagglutinin (HA) cleavage site and neuraminidase (NA) stalk. The original H9N2 AI vir...

Avian influenza viruses (AIV) of H5N1 and H9N2 subtypes have zoonotic and pandemic potential. 377 out of 633 human infections with H5N1 virus were fatal and human infections by H9N2 virus were infrequently reported to the World Health Organization. Some H9N2 viruses either possessed genes similar to the H5N1 virus or were claimed to donate gene segments to H5N1 virus. Both features were reporte...

Although smokers have increased susceptibility and severity of seasonal influenza virus infection, there is no report about the risk of 2009 pandemic H1N1 (pdmH1N1) or avian H9N2 (H9N2/G1) virus infection in smokers. In our study, we used mouse model to investigate the effect of cigarette smoke on pdmH1N1 or H9N2 virus infection. Mice were exposed to cigarette smoke for 21 days and then infecte...

BACKGROUND Mannose-binding lectin (MBL) is a pattern-recognition molecule, which functions as a first line of host defense. Pandemic H1N1 (pdmH1N1) influenza A virus caused massive infection in 2009 and currently circulates worldwide. Avian influenza A H9N2 (H9N2/G1) virus has infected humans and has the potential to be the next pandemic virus. Antiviral function and immunomodulatory role of MB...