Animal-side serologic assay for rapid detection of Mycobacterium Bovis infection in multiple species of free-ranging wildlife

Numerous species of mammals are susceptible to Mycobacterium bovis, the causative agent of bovine tuberculosis (TB). Several wildlife hosts have emerged as reservoirs of M. bovis infection for domestic livestock in different countries. In the present study, blood samples were collected from Eurasian badgers (n = 1532), white-tailed deer (n = 463), brushtail possums (n = 129), and wild boar (n = 177) for evaluation of antibody responses to M. bovis infection by a lateral-flow rapid test (RT) and multiantigen print immunoassay (MAPIA). Magnitude of the antibody responses and antigen recognition patterns varied among the animals as determined by MAPIA; however, MPB83 was the most commonly recognized antigen for each host studied. Other seroreactive antigens included ESAT-6, CFP10, and MPB70. The agreement of the RT with culture results varied from 74% for possums to 81% for badgers to 90% for wild boar to 97% for white-tailed deer. Small numbers of wild boar and deer exposed to M. avium infection or paratuberculosis, respectively, did not cross-react in the RT, supporting the high specificity of the assay. In deer, whole blood samples reacted similarly to corresponding serum specimens (97% concordance), demonstrating the potential for field application. As previously demonstrated for badgers and deer, antibody responses to M. bovis infection in wild boar were positively associated with advanced disease. Together, these findings suggest that a rapid TB assay such as the RT may provide a useful screening tool for certain wildlife species that may be implicated in the maintenance and transmission of M. bovis infection to domestic livestock.

Hydatid Disease in Boreal Regions

It is the purpose of this paper to review the status of hydatid disease (caused by Echinococcus spp.) in the boreal regions of the world. Its importance has long been recognized in Eurasian countries, but only during recent years have investigators added anything significant to the knowledge of hydatid disease in North America. There is need to disseminate up-to-date information among medical workers in Canada and Alaska, where the disease is endemic in northern regions having a large aboriginal population. Therefore, particular emphasis will be placed on the situation in boreal North America.

Cytogenic Evidence for the Specific Distinction of an Alaskan Marmot, Marmota broweri Hall and Gilmore (Mammalia: Sciuridae)

Cytogenetic studies based upon somatic cells (bone marrow) have disclosed that the marmot hitherto designated Marmota caligata broweri Hall and Gilmore, occurring in the Brooks Range of Arctic Alaska, differs from M. c. caligata (Eschscholtz) in number of chromosomes (2n=36 as compared with 2n=42 in M. caligata) and in proportions of chromosomal types. Typical karyograms for the two species are presented. It is concluded that the Brooks Range marmot is specifically distinct from M. caligata, the applicable name being Marmota broweri Hall and Gilmore. Also determined were diploid chromosome numbers for two other Nearctic species of marmots, M. flaviventris (Audubon and Bachman), with 42, and M. olympus (Merriam), with 40. It is suggested that M. broweri survived the last (Wisconsin) glaciations in the amphi-Beringian refugium, and that its closest affinities may be with one of the Eurasian species of Marmota.

The Specific Status of the Narrow-Skulled Vole (Subgenus Stenocranius Kashchenko) in North America

On morphological and zoogeographical grounds, discussed in the present paper, it is concluded that the narrow-skulled vole in North America, previously designated Microtus (Stenocranius) miurus Osgood, is conspecific with the Eurasian M. (Stenocranius) gregalis Pallas. Fourteen subspecies in Eurasia and 5 in North America are now recognized, but it is probable that the number in Eurasia will be reduced through future investigation. The Eurasian subspecies of this vole comprise two major groups, of which one occupies the tundra zone and the other occurs across central Asia below latitude 60° N; their geographic ranges are largely separate but evidently become confluent in northeastern Siberia. The members of the northern group of Eurasian subspecies and the North American forms are closely related; the present distribution of the latter indicates post-glacial dispersal from the Amphiberingian Refugium. It is believed that the tundra-inhabiting voles in Eurasia likewise survived the Pleistocene glaciations in northern refugia, while the members of the southern group of subspecies probably represent populations that survived south of the limits of the continental glaciers. The ranges of the two Eurasian groups probably have become confluent during post-glacial time in northeastern Siberia as a result of the southward spread of the northern forms. At least, the subspecies having the intervening range closely resembles members of the northern group. Some of the ecological and ethological characteristics of these voles are briefly discussed. The chromosome number of one of the North American subspecies of narrow-skulled vole was determined to be 54; this is the first time that the chromosomes of a member of the subgenus Stenocranius have been investigated. A karyogram has been included. German abstract: Auf morphologischen und tiergeographischen Grundlagen, die in dieser Arbeit besprochen wurden, ist festgestellt worden, daß die schmalschädlige Wiihlmaus in Nordamerika, friiher Microtus (Stenocranius) miurus Osgood bezeichnet, mit der palaearktischen Art M. (Stenocranius) gregalis Pallas identisch ist. Zur Zeit gelten 14 Unterarten in Eurasien und 5 in Nordamerika als unterscheidbar; vermutlich aber wird die Zahl der palaearktischen Unterarten durch eingehendere Untersuchungen künftig vermindert werden. Auf Grund ihrer Verbreitung bilden die palaearktischen Unterarten zwei beinahe vollständig getrennte Gruppen. Die Wühlmäuse der nördlichen Gruppe bewohnen die Tundrazone, während die Vertreter der zweiten Gruppe über Mittelasien südlicher als 60° N.B. verbreitet sind. Die Verbreitungsgebiete der zwei Gruppen verbinden sich anscheinend. Die nordamerikanischen schmalschädligen Wühlmäuse sind mit den in der Tundrazone vorkommenden palaearktischen Formen nahe verwandt; sie haben sich wahrscheinlich während der Postglazialzeit aus dem Amphiberingschen Refugium verbreitet. Möglicherweise überlebten die tundrabewohnenden Wühlmäuse Eurasiens die Eiszeit ebenfalls in vereinzelten Refugien in Nordostsibirien, während die Formen der südlichen Gruppe sie jenseits der Grenzen des Festlandsgletschers überlebten. Wahrscheinlich wurden die zwei Verbreitungsgebiete dieser Art in Eurasien erst während der Postglazialzeit durch das Vordringen der nordischen Formen verbunden, da eine nähere Verwandtschaft zwischen den nördlichen und der dazwischenliegenden Unterart besteht. Einige ökologische und ethologische Eigentümlichkeiten dieser Wühlmäuse werden kurz besprochen. Es wurde festgestellt, daß eine der nordamerikanischen Unterarten der schmalschädligen Wühlmaus 54 Chromosomen hat; sie ist der einzige Vertreter der Untergattung Stenocranius, dessen Chromosomen untersucht worden sind.