Location: Infectious Bacterial Diseases Research
Project Number: 5030-32000-221-12-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Jul 1, 2020
End Date: May 31, 2023
The overall objective is to develop MAP live-attenuated vaccines that can differentiate vaccinated from infected animals (DIVA) for MAP diagnosis.
The approach is to: (1) Generate unmarked in-frame deletion mutants with DIVA capabilities and the potential to induce protective immunity. Invasion and intracellular survival in bovine macrophages will be determined; (2) Test novel antigens for DIVA capabilities. DIVA capable diagnostic tests will be developed to work with the candidate vaccine mutants. We will expand the humoral immunity test to additional samples from natural and experimentally infected animals, and develop cellular immunity tests; and (3) Assess the immunopathogenicity and skin test reactivity of MAP mutants and their complemented strains in calves.