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Not AvailableThe molecular pathogenesis of avian influenza infection varies greatly with individual bird species and virus strain. The molecular pathogenesis of the highly pathogenic avian influenza virus (HPAIV) or the low pathogenic avian influenza virus (LPAIV) infection in avian species remains poorly understood. Thus, global immune response of chickens infected with HPAI H5N1 (A/duck/India/02CA10/2011) and LPAI H9N2 (A/duck/India/249800/2010) viruses was studied using microarray to identify crucial host genetic components responsive to these infection. HPAI H5N1 virus induced excessive expression of type I IFNs (IFNA and IFNG), cytokines (IL1B, IL18, IL22, IL13, and IL12B), chemokines (CCL4, CCL19, CCL10, and CX3CL1) and IFN stimulated genes (OASL, MX1, RSAD2, IFITM5, IFIT5, GBP 1, and EIF2AK) in lung tissues. This dysregulation of host innate immune genes may be the critical determinant of the severity and the outcome of the influenza infection in chickens. In contrast, the expression levels of most of these genes was not induced in the lungs of LPAI H9N2 virus infected chickens. This study indicated the relationship between host immune genes and their roles in pathogenesis of HPAIV infection in chickens.Not Availabl

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Not AvailableThis study reports the highly pathogenic avian influenza (HPAI) H5N1 virus load estimation in different organs of chickens following experimental infection. The TaqMan probe based quantitative real-time reverse transcriptase PCR (qRT-PCR) assay was optimized for quantification of HPAI virus RNA in tissues collected from experimentally infected chickens. Conserved region in the matrix gene of avian influenza virus served as target for the primers and TaqMan probe. A recombinant plasmid containing the matrix protein gene amplicon was constructed for a quantitative estimation of copy numbers of the target gene. Quantification of avian influenza virus RNA was accomplished using a standard curve generated from ten-fold serial dilutions of IVT RNA generated from recombinant plasmid containing matrix gene. High viral RNA load was detected in spleen, brain and lung indicating enormous replication of virus in these tissues. However, spleen showed significantly higher viral RNA load (P<0.03) over other organs.Not Availabl

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Not AvailableThe post infection virus isolated at the latest time point from the infected duck showed mutations in HA segment which were absent in post infection virus isolated at the latest time point from the contact challenged chickens. The genome sequencing of the highly pathogenic avian influenza virus (HPAI) derived directly from a cloacal swab of infected duck revealed substantial sequence heterogeneity.Not Availabl