Blackburn Jason K, Asher Valpa, Stokke Stephen, Hunter David L, Alexander Kathleen A
1 Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida 32611, USA.
J Wildl Dis. 2014 Apr;50(2):393-6. doi: 10.7589/2013-08-204. Epub 2014 Jan 31.
Bacillus anthracis, the cause of anthrax, was recovered from two plains bison (Bison bison bison) cows killed by wolves (Canis lupus) in Montana, USA, without associated wolf mortality in July 2010. This bison herd experienced an epizootic in summer 2008, killing ∼ 8% of the herd, the first documented in the region in several decades. No wolf deaths were associated with the 2008 event. Surveillance has continued since 2008, with research, ranch, and wildlife personnel diligent during summer. As part of this, we tested wolf-killed bison and elk (Cervus elaphus) for anthrax during the 2010 summer using lateral flow immunochromatographic assays (LFIA). Two bison cows were positive for protective antigen, confirming active bacteremia. The LFIA results were confirmed with traditional bacteriology recovering viable B. anthracis. No wolf fatalities were associated with the bison deaths, despite consuming the meat. Low-level anthrax occurrence in large, rough terrain landscapes remains difficult to detect, particularly if mortality in the herbivore host is not a consequence of infection. In these instances, surveillance of predators with large home ranges may provide a more sensitive indicator of anthrax emergence or reemergence in such systems. Though speculative, it is also possible that anthrax infection in the bison increased predation risk. These results also suggest B. anthracis remains a threat to wildlife and associated livestock in southwestern Montana.
炭疽杆菌是炭疽病的病原体，2010年7月在美国蒙大拿州从两头被狼（犬属狼疮）咬死的平原野牛（美洲野牛指名亚种）母牛身上分离出该病菌，当时没有狼死亡的情况。这群野牛在2008年夏天经历了一次 epizootic，约8%的牛群死亡，这是该地区几十年来首次有记录的此类事件。2008年的事件没有导致狼死亡。自2008年以来一直在进行监测，夏季时研究人员、牧场主和野生动物工作人员都很勤勉。作为其中一部分，我们在2010年夏天使用侧向流动免疫层析测定法（LFIA）对被狼咬死的野牛和麋鹿（马鹿）进行了炭疽检测。两头野牛母牛的保护性抗原呈阳性，证实存在活动性菌血症。LFIA结果通过传统细菌学方法得到证实，分离出了活的炭疽杆菌。尽管狼食用了野牛的肉，但没有狼因野牛死亡而死亡。在广阔、地形复杂的地区，炭疽的低水平发生仍然难以检测到，特别是如果食草动物宿主的死亡不是感染的结果。在这些情况下，对活动范围大的捕食者进行监测可能会提供一个更敏感的指标，以指示此类系统中炭疽的出现或再次出现。虽然只是推测，但野牛感染炭疽也有可能增加被捕食的风险。这些结果还表明，炭疽杆菌仍然对蒙大拿州西南部的野生动物和相关家畜构成威胁。
