Control of Emerging and Re-Emerging Poultry Respiratory Diseases in the United States

NON-TECHNICAL SUMMARY: Research will produce greater understanding of disease reservoirs, processes and control interventions. Reduced mortality and condemnation will result through the use of improved diagnostic tools, vaccines and bio-security measures. Consumers will enjoy safe, healthy, and competitively priced eggs and poultry meat products.

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APPROACH: <BR> Objective 1. AVIAN INFLUENZA VIRUS (AIV) (AUBURN, CONNECTICUT, DELAWARE, INDIANA, MARYLAND, MINNESOTA, OHIO) Surveillance will be performed in commercial poultry, backyard poultry, live bird markets and auctions, wild aquatic birds, and swine. The susceptibility of guinea fowl, turkeys, domestic ducks, and geese to AIVs from wild bird reservoirs (Pereda et al., 2008) will be determined. <BR> <BR> Objective 2: ORNITHOBACTERIUM RHINOTRACHEALE (ORT) (MINNESOTA, USDA-NADC) A 3-primer PCR assay for identification of ORT will be developed and optimized. Universally conserved forward and reverse primers, as well as an ORT-specific forward primer, all derived from the 16S rRNA genes, will be used. <BR> <BR> Objective 3: AVIAN INFLUENZA VIRUS (AIV) (DELAWARE, MARYLAND, MINNESOTA, OHIO) H5 LPAI isolates of wild bird origin will be characterized in chickens, ducks and turkeys. E. COLI (DELAWARE, MINNESOTA) The polymicrobial interactions of Mycoplasma gallisepticum, NDV, or IBV with avian pathogenic E. coli (APEC) involved in respiratory disease in chickens will be investigated. INFECTIOUS BRONCHITIS VIRUS (IBV) (GEORGIA, MINNESOTA) The potential interference between ILTV, NDV and IBV live vaccines in chickens will be investigated. The interaction of IBV, E. coli, and mycoplasma involved in respiratory disease in chickens will be studied. INFECTIOUS BURSAL DISEASE VIRUS (IBDV) (DELAWARE, INDIANA, MINNESOTA, OHIO) The pathogenic and antigenic properties of field strains will be characterized. MYCOPLASMAS (GEORGIA, MINNESOTA) The genetic relatedness and pathogenicity of selected field isolates of respiratory viruses and mycoplasmas will be studied in chickens. POULTRY ENTERITIS SYNDROME (PES) (MINNESOTA) Poult enteritis syndrome (PES) will be experimentally reproduced and interactions of PES and respiratory infections will be studied. <BR> <BR> Objective 4: AVIAN PNEUMOVIRUS (APV) (MARYLAND, MINNESOTA) A safe and effective recombinant APV vaccine will be developed. Recombinant APVs will be generated entirely from cloned cDNA based on independent mechanisms of attenuation (Govindarajan et al., 2006). Vaccine candidates will be evaluated for their ability to protect turkeys vs. APV challenge. The engineered vaccine viruses will also be marker vaccines enabling easy but accurate serological differentiation between infected and vaccinated birds. Using reverse genestics, a biomarker containing recombinant APV will be developed to differentiate vaccine from wild type APV. The N, P, M2 and L genes will be co-transfected along with the complete AMPV cDNA in order to produce infectious virions. Different biomarkers, GFP, 6x His tag, or DNA, will be evaluated for use in the recombinant virus (Kong et al. 2006; 2007). AVIAN PNEUMOVIRUS (APV) (MINNESOTA) A killed mucosal vaccines to protect turkeys and chickens against respiratory viral infections including APV will be developed. A biomarker containing recombinant APV to differentiate vaccine from wild type virus will be designed. The G gene from a vaccine strain of APV (MN-1a-p63) will be cloned into an infectious clone to generate a recombinant vaccine.