Co-Infection Studies in Chickens and Turkeys with Different Respiratory Pathogens

PI: Mary J. Pantin-Jackwood

Objective 2:
Investigate the multifactorial etiology involving poultry respiratory diseases; Activity 2.1: Study the interactions of relevant respiratory and immunosuppressive agents based on species (broiler, layer, and turkeys), their clinical outcomes, transmission patterns, and potential changes in vaccination and diagnostic strategies.

Project 2.1.1.
Co-infection of broiler chickens with LPAIV, IBV and Mycoplasma to reproduce bronchial casts and mortality reported with LPAIV infections in the field (Pantin-Jackwood M.). We will inoculate SPF broilers with LPAIV and IBV and/or Mycoplasma. Initially we will use an H5N2 LPAI Mexican isolate, an IBV vaccine strain and a M. synoviae (MS) isolate. Later, other strains will be examined, and similar experiments will be conducted in commercial broilers to account for other variables. The pathogens will be given simultaneously or sequentially and in different combinations. Metrics that will be evaluated include the outcome of infection (clinical signs, lesions), presence of the viruses and mycoplasmas in tissues, duration and titer of shedding, transmission to contacts, and seroconversion. The number of birds used for the experiments will be determined by our previous studies and are based on sample sets sufficient to demonstrate statistical significance. We will add additional 2-4 birds to each test for sampling of tissues for histopathology, virus isolation and other tests that require termination.

Project 2.1.2.
Co-infection of turkeys with respiratory pathogens including LPAIV, NDV, and Mycoplasma (Pantin-Jackwood M, Afonso C). We will inoculate SPF turkeys of different ages with LPAIV, NDV and Mycoplasma in different combinations. Several subtypes of LPAI viruses can infect turkeys, including strains of swine origin, causing diverse clinical signs. Initially we will use a poultry origin LPAI isolate, a NDV vaccine strain and a M. meleagridis (MM) isolate. Later, other strains will also be examined, and similar experiments will be conducted in commercial turkeys to account for other variables. Experiments and data analysis will be conducted similarly as described above.

Yearly Goals:

Year 1:
Co-infection of SPF and commercial broiler chickens with H5N2 LPAIV, IBV (vaccine strain) and MS.

Year 2:
Co-infection of SPF and commercial turkeys with a poultry LPAIV isolate, NDV (vaccine strain), and MM.

Year 3:
Co-infection of commercial broiler chickens with H9N2 LPAIV, IBV (virulent strain) and MS; and co-infection of commercial turkeys with a swine-origin LPAIV isolate, NDV (vaccine strain), and MM.

Years 4 & 5:
Complementary co-infection studies will be conducted based on the results obtained in the previous years.

Potential Impact and Expected Outcomes:
These studies will provide important and much needed information on the interaction of respiratory pathogens in poultry, which will help improve diagnostics and vaccination strategies needed to control respiratory syndromes in poultry. Specifically, these studies will provide practical information on what to expect in regards to clinical outcomes of co-infections with respiratory pathogens and will help improve control of the diseases by understanding patterns of shedding and transmission of these pathogens when co-infecting birds.

wpadminProject Patin Jackwood