Prevalence of Mycoplasma spp. in the respiratory tract of healthy North American bison (Bison bison) and comparison with serum antibody status

Authors: Register, Karen; JONES, LEE - Us Fish And Wildlife Service; Boatwright, Jr, William; SHURY, TODD - Parks Canada, Banff National Park; WOODBURY, M - University Of Saskatchewan; HAMILTON, ROBERT - Nature Conservancy; TREANOR, JOHN - Yellowstone Heritage And Research Center; DYER, NEILL - North Dakota State University; NOL, PAULINE - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center

Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2020
Publication Date: 7/5/2021
Citation: Register, K.B., Jones, L.C., Boatwright Jr, W.D., Shury, T.K., Woodbury, M., Hamilton, R.G., Treanor, J., Dyer, N., Nol, P. 2021. Prevalence of Mycoplasma spp. in the respiratory tract of healthy North American bison (Bison bison) and comparison with serum antibody status. Journal of Wildlife Diseases. 57(3):683-688. https://doi.org/10.7589/JWD-D-20-00198.
DOI: https://doi.org/10.7589/JWD-D-20-00198

Interpretive Summary: Mycoplasma bovis causes respiratory and reproductive diseases in North American bison, imposing a substantial degree of animal suffering and significant economic losses. Developing measures to limit the impact of related disease requires an understanding of how the bacterium spreads among bison, about which little is currently known. This study addresses the question of whether healthy bison can be infected with M. bovis, potentially serving as unrecognized sources of exposure, and whether those bison can be identified by testing their serum for related antibodies. We looked for M. bovis in the nasal cavity or tonsil of 500 healthy bison from 11 locations in the USA and two in Canada. M. bovis was detected in 15 bison (3.0 percent) representing at least 3 herds in the USA and Canada. One of four other closely related mycoplasmas not generally associated with disease was identified from an additional 156 bison (31.2 percent). Only 46.2 percent of the bison positive for M. bovis had detectable antibodies. We also found antibodies reactive with M. bovis in 5.2 percent of the bison that tested negatively for the bacterium. These data reveal that M. bovis can be carried in the upper respiratory tract of healthy bison with no prior history or clinical signs of mycoplasmosis and that serum testing will fail to identify a large proportion of those carriers. Whether carriage of mycoplasmas other than M. bovis can trigger the production of cross-reactive antibodies that cause a false positive serum test for M. bovis requires further study.

Technical Abstract: Mycoplasma bovis is a primary cause of respiratory and reproductive diseases in North American bison, with significant morbidity and mortality. Developing measures to limit the impact of mycoplasmosis requires an understanding of the epidemiology of M. bovis, about which little is known. This study addresses the question of whether healthy bison might be carriers of M. bovis, potentially serving as unrecognized sources of exposure. We used culture and PCR to identify mycoplasmas in the upper respiratory tract of 500 healthy bison from 11 locations in the USA and two in Canada. M. bovis was detected in 15 bison (3.0 percent) representing at least 3 herds in the USA and Canada, while one of four other mycoplasmas was identified from an additional 156 bison (31.2 percent). Mycoplasma bovirhinis was identified most frequently, in 143 bison (28.6 percent) representing at least 10 herds. Of the 382 bison for which serum was available only 6/13 positive for M. bovis (46.2 percent) tested positively with an M. bovis ELISA, as did 19/369 negative for M. bovis (5.2 percent). These data reveal that M. bovis can be carried in the upper respiratory tract of healthy bison with no prior history or clinical signs of mycoplasmosis and that a large proportion of carriers may fail to seroconvert. Whether carriage of other mycoplasmas can trigger cross-reactive antibodies that may confound M. bovis serology requires further study.