|Knowles, Donald - Don|
Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2007
Publication Date: 2/1/2008
Publication URL: http:///ddr.nal.usda.gov/dspace/bitstream/10113/14954/1/IND44013040.pdf
Citation: Besser, T.E., Cassirer, K.A., Potter, K.A., Vanderschalie, J., Fischer, A., Knowles Jr, D.P., Herndon, D.R., Rurangirwa, F.R., Weiser, G.C., Srikumaran, S. 2008. Association of Mycoplasma ovipneumoniae Infection with Population-Limiting Respiratory Disease in Free-Ranging Rocky Mountain Bighorn Sheep (Ovis canadensis canadensis). Journal of Clinical Microbiology. 46(2):423-430. Interpretive Summary: Population limiting lung disease in bighorn sheep is an important issue for management of domestic and wildlife animal populations. The data within this report shows that Mycoplasma ovipneumoniae is likely to play and important role in lung disease in bighorn sheep. It is not known if Mycoplasma ovipneumoniae plays a primary or predisposing role in the disease process.
Technical Abstract: Bronchopneumonia is a population-limiting disease in bighorn sheep in much of western North America. Previous investigators have isolated diverse bacteria from the lungs of affected sheep, but no single bacterial species is consistently present, even within single epizootics. We obtained high-quality diagnostic specimens from nine pneumonic bighorn sheep in three populations and analyzed the bacterial populations present in bronchoalveolar lavage specimens of seven by using a culture-independent method (16S rRNA gene amplification and clone library analyses). Mycoplasma ovipneumoniae was detected as a predominant member of the pneumonic lung flora in lambs with early lesions of bronchopneumonia. Specific PCR tests then revealed the consistent presence of M. ovipneumoniae in the lungs of pneumonic bighorn sheep in this study, and M. ovipneumoniae was isolated from lung specimens of five of the animals. Retrospective application of M. ovipneumoniae PCR to DNA extracted from archived formalin-fixed, paraffin-embedded lung tissues of historical adult bighorn sheep necropsy specimens supported the association of this agent with bronchopneumonia (16/34 pneumonic versus 0/17 nonpneumonic sheep were PCR positive [P < 0.001]). Similarly, a very strong association was observed between the presence of one or more M. ovipneumoniae antibody-positive animals and the occurrence of current or recent historical bronchopneumonia problems (seropositive animals detected in 9/9 versus 0/9 pneumonic and nonpneumonic populations, respectively [P < 0.001]). M. ovipneumoniae is strongly associated with bronchopneumonia in free-ranging bighorn sheep and is a candidate primary etiologic agent for this disease.