SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
Vet Parasitol. 2012 Nov 23;190(1-2):19-28. doi: 10.1016/j.vetpar.2012.06.017. Epub 2012 Jun 23.
Bovine besnoitiosis, caused by Besnoitia besnoiti, is considered to be emergent in Europe and responsible for severe economic losses due to the chronic and debilitating course of the disease but has not been reported in North America. Besnoitia tarandi is a related species and it has been reported in reindeer and caribou from different locations of the Arctic Pole, including North America. Diagnosis of clinical besnoitiosis is largely based on the recognition of dermal grossly visible tissue cysts of Besnoitia. Nothing is known of cross reactivity between B. besnoiti and B. tarandi species. Here, we evaluated the use of serological tests employed in the diagnosis of bovine besnoitiosis for the detection of Besnoitia spp. infections in different wild ruminant species (caribou, elk, mule-deer, white-tailed deer, moose, muskox and bison) from Canada and investigated cross-reactivity between B. besnoiti and B. tarandi species by indirect immunofluorescence antibody test and Western blot. For this, species-specific antibodies were obtained in rabbits experimentally infected with B. besnoiti and B. tarandi. Marked cross reactivity was found between B. besnoiti and B. tarandi. For the first time, antibodies to Besnoitia spp. infection were found in 16 of 20 caribou (Ranginfer tarandus), seven of 18 muskox (Ovibos moschatus), one of three bison (Bison bison), but not in 20 elk (Cervus canadensis), 20 white tailed deer (Odocoileus virginianus), and 20 moose (Alces alces) in Canada; results were similar using B. besnoiti and B. tarandi as antigen. There was no cross reactivity between the two Besnoitia species, Neospora caninum and Toxoplasma gondii with the cut-offs applied that prevented to observe it. The present study provides evidence that the serological assays can be useful to accomplish large scale prevalence studies in caribou and other wildlife species. Further studies are needed to study sylvatic and domestic cycle of B tarandi and B. besnoiti.
牛贝氏贝虫病由贝氏贝虫引起，被认为在欧洲呈新兴态势，由于该病的慢性和虚弱病程，给经济造成严重损失，但在北美洲尚未有报道。亲缘种 Besnoitia tarandi 已见于不同北极地区的驯鹿和北美野牛。临床贝氏贝虫病的诊断主要基于对 Besnoitia 的皮肤肉眼可见的组织囊肿的识别。关于 B. besnoiti 和 B. tarandi 种之间的交叉反应性尚一无所知。在此，我们评估了用于诊断牛贝氏贝虫病的血清学检测方法，以检测来自加拿大的不同野生反刍动物物种（驯鹿、麋鹿、骡鹿、白尾鹿、驼鹿、麝香牛和野牛）中的 Besnoitia spp. 感染，并通过间接免疫荧光抗体试验和 Western blot 研究了 B. besnoiti 和 B. tarandi 种之间的交叉反应性。为此，我们在实验感染 B. besnoiti 和 B. tarandi 的兔中获得了种特异性抗体。发现 B. besnoiti 和 B. tarandi 之间存在明显的交叉反应性。首次在 20 头驯鹿（Rangifer tarandus）中的 16 头、18 头麝香牛（Ovibos moschatus）中的 7 头、3 头野牛（Bison bison）中的 1 头中发现了 Besnoitia spp. 感染的抗体，但在加拿大的 20 头麋鹿（Cervus canadensis）、20 头白尾鹿（Odocoileus virginianus）和 20 头驼鹿（Alces alces）中未发现抗体；使用 B. besnoiti 和 B. tarandi 作为抗原时，结果相似。两种 Besnoitia 种、新孢子虫（Neospora caninum）和刚地弓形虫（Toxoplasma gondii）与应用的截断值之间没有交叉反应性，这阻止了我们观察到这种情况。本研究提供了证据表明，血清学检测可用于在驯鹿和其他野生动物物种中进行大规模流行情况研究。需要进一步的研究来研究 B tarandi 和 B. besnoiti 的森林和家养循环。
