Abstract：
Mycoplasma bovis is a bacterial pathogen endemic to cattle. In the early 2000s, M. bovis emerged as a cause of respiratory disease in American bison (Bison bison), causing significant morbidity and mortality. Bison herds that experience an outbreak of M. bovis are at higher risk for subsequent outbreaks, suggesting that chronic, subclinical infections can be established. Antemortem testing is therefore crucial to disease management; however, the precise sampling method to maximize detection of M. bovis in bison is unknown. We evaluated two sample types-superficial nasal swabs and deep nasopharyngeal swabs-collected from apparently healthy or symptomatic bison from January 2021 through December 2022. We used real-time PCR to detect M. bovis in 76/938 bison (8.1%) from 11 herds. For bison testing positive on at least one swab type, M. bovis was detected in 63/76 (82.8%) deep nasopharyngeal swabs and 29/73 (38.1%) superficial nasal swabs. Agreement between swabs for positive bison was 21% (n=16, kappa coefficient 0.319). We conclude that deep nasopharyngeal swabbing is more sensitive than superficial nasal swabbing for detection of M. bovis in bison and that low agreement between methods may be related to stage of infection. We further tested pooled samples by PCR and found that pooling of up to five samples can be effective to increase throughput and minimize costs. Management of wild bison relies on the ability to relocate animals to maintain gene flow and healthy populations. Sensitive and specific diagnostic tests are needed to inform decisions and minimize risk of transmission, especially from subclinical carriers. This study provides valuable insight that will inform best practices for M. bovis testing, thereby supporting the conservation of bison as healthy wildlife, which in turn promotes ecological restoration, safeguards cultural practices of Tribal Nations, and upholds the bison as a unique American icon.
摘要：
牛支原体是牛特有的细菌病原体。在2000年代初期，牛分枝杆菌是美国野牛（Bisonbison）呼吸道疾病的原因之一，导致显著的发病率和死亡率。经历牛分枝杆菌爆发的野牛群随后爆发的风险更高，表明慢性，可以建立亚临床感染。因此，死前测试对疾病管理至关重要；然而，精确的采样方法来最大限度地检测野牛中的牛分枝杆菌是未知的。我们评估了从2021年1月至2022年12月从明显健康或有症状的野牛中收集的两种样本类型-浅表鼻拭子和深鼻咽拭子。我们使用实时PCR检测了11只牛群的76/938野牛（8.1％）中的牛分枝杆菌。对于至少一种拭子类型的野牛测试呈阳性，牛分枝杆菌在63/76（82.8％）的深鼻咽拭子和29/73（38.1％）的浅表鼻拭子中检测到。阳性野牛拭子之间的一致性为21％（n=16，卡帕系数0.319）。我们得出的结论是，对于检测野牛中的牛分枝杆菌，深鼻咽拭子比浅部鼻拭子更敏感，并且方法之间的低一致性可能与感染阶段有关。我们通过PCR进一步测试了合并的样品，发现最多5个样品的合并可以有效地增加通量并最小化成本。野生野牛的管理依赖于重新安置动物以维持基因流动和健康种群的能力。需要进行敏感和特定的诊断测试，以告知决策并最大程度地减少传播风险，尤其是亚临床携带者.这项研究提供了有价值的见解，将为牛分枝杆菌测试提供最佳实践，从而支持保护野牛作为健康的野生动物，反过来促进生态恢复，保障部落民族的文化习俗，并将野牛视为独特的美国偶像。
