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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Ruminant Diseases and Immunology Research » Research » Publications at this Location » Publication #424232
Research Project: Host-pathogen Interactions and Control Strategies for Bacterial Respiratory Pathogens in Cattle

Location: Ruminant Diseases and Immunology Research

Title: A modified-live Mannheimia haemolytica expressing Mycoplasma bovis EFTu and Hsp70 induced systemic and mucosal antibody responses in American bison but failed to fully protect against Mycoplasma bovis challenge

Author
item Kaplan, Bryan
item Dassanayake, Rohana
item Chriswell, Bradley
item Boatwright Jr, William
item Olsen, Steven
item Palmer, Mitchell
item Boggiatto, Paola
item KANIPE, CARLY - Oak Ridge Institute For Science And Education (ORISE)
item Casas, Eduardo
item BRIGGS, ROBERT - Retired ARS Employee
item Tatum, Fred

Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2025
Publication Date: 8/11/2025
Citation: Kaplan, B.S., Dassanayake, R.P., Chriswell, B.O., Boatwright Jr, W.D., Olsen, S.C., Palmer, M.V., Boggiatto, P.M., Kanipe, C.R., Casas, E., Briggs, R.E., Tatum, F.M. 2025. A modified-live Mannheimia haemolytica expressing Mycoplasma bovis EFTu and Hsp70 induced systemic and mucosal antibody responses in American bison but failed to fully protect against Mycoplasma bovis challenge. Veterinary Microbiology. 309. Article 110680. https://doi.org/10.1016/j.vetmic.2025.110680.
DOI: https://doi.org/10.1016/j.vetmic.2025.110680

Interpretive Summary: Mycoplasma bovis (M. bovis) is a bacteria that causes severe respiratory disease in American bison. Despite causing many high mortality outbreaks for over 20 years, there is no commercially available vaccine licensed for use in bison. In this study, we evaluated an experimental vaccine comprised of an attenuated modified-live Mannheimia haemolytica expressing M. bovis proteins, EFTu and Hsp70, in bison. Vaccinated bison produced antibody against the M. bovis proteins as well as Mannheimia haemolytica. Both vaccinated and unvaccinated bison were then intranasally infected with M. bovis. Vaccinated bison had lower mycoplasma colonization of the nasal cavity, trachea, and joints as well as fewer lung lobes with signs of damage. These results show that this modified-live vaccine can prevent systemic M. bovis infection in bison.

Technical Abstract: Mycoplasma bovis (M. bovis) is an emerging pathogen in American bison (Bison bison) responsible for high mortality epizootics of severe pneumonia and systemic disease. Though M. bovis poses a significant threat to bison conservation and ranching, there are no commercial vaccines licensed for use in this species. To this end, novel modified-live Mannheimia haemolytica (M. haemolytica) vaccine strains, serotypes 1 and 6, secreting inactive leukotoxin fused to truncated M. bovis Elongation Factor Tu (EFTu) and Heat shock protein (Hsp) 70 (EFTu-Hsp70-'lktCAV4) were evaluated for efficacy in bison. Modified-live M. haemolytica were administered intranasally and both serotypes were recovered from the palatine tonsils of bison. Bison inoculated with the two M. haemolytica EFTu-Hsp70- 'lktCAV4 strains seroconverted and produced mucosal antibodies to the M. bovis antigens and M. haemolytica prior to intranasal challenge with M. bovis. Vaccinated bison were found to have fewer affected lung lobes and lower bacterial titers in the nasal cavities, trachea, and joints compared to controls that received M. haemlytica 'lktCAV4, lacking the M. bovis proteins. These results demonstrate that modified-live M. haemolytica vaccine strains expressing M. bovis antigens can prevent systemic M. bovis infection in bison and potentially provide protection against M. haemolytica.