This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Hamir, A. N. Articles by Richt, J. A. Search for Related Content PubMed PubMed Citation Articles by Hamir, A. N. Articles by Richt, J. A.

Second Passage of Sheep Scrapie and Transmissible Mink Encephalopathy (TME) Agents in Raccoons (Procyon lotor)

Abstract

To determine the transmissibility and pathogenicity of sheep scrapie and transmissible mink encephalopathy (TME) agents derived from raccoons (first passage), raccoon kits were inoculated intracerebrally with either TME (one source) or scrapie (two sources—each in separate groups of raccoons). Two uninoculated raccoon kits served as controls. All animals in the TME-inoculated group developed clinical signs of neurologic dysfunction and were euthanatized between postinoculation month (PIM) 6 and 8. Raccoons in the two scrapie-inoculated groups manifested similar clinical signs of disease, but such signs were observed much later and the animals were euthanized between PIM 12 and 18. Necropsy revealed no gross lesions in any of the raccoons. Spongiform encephalopathy was observed by use of light microscopy, and the presence of protease-resistant prion protein (PrP^res) was detected by use of immunohistochemical (IHC) and Western blot analytic techniques. Results of IHC analysis indicated a distinct pattern of anatomic distribution of PrP^res in the TME- and scrapie-inoculated raccoons. These findings confirm that TME and sheep scrapie are experimentally transmissible to raccoons and that the incubation periods and IHC distribution for both agents are distinct. Therefore, it may be possible to use raccoons for differentiating unknown transmissible spongiform encephalopathy (TSE) agents. Further studies, with regard to the incubation period and the pattern of PrP^res deposition by use of IHC analysis in bovine spongiform encephalopathy and for other isolates of scrapie, chronic wasting disease, and TME in raccoons are needed before the model can be further characterized for differentiation of TSE agents.

Key words: Cross-species transmission; immunohistochemistry (PrP^res), raccoons (Procyon lotor); sheep scrapie; spongiform encephalopathy; strain differentiation; transmissible mink encephalopathy.

Request reprints from Dr. A. N. Hamir, National Animal Disease Center, ARS, USDA, 2300 Dayton AvenueP. O. Box 70, Ames, IA 50010 (USA). E-mail: ahamir{at}nadc.ars.usda.gov

This article has been cited by other articles:

				A. N. Hamir, R. A. Kunkle, J. M. Miller, R. C. Cutlip, J. A. Richt, M. E. Kehrli Jr, and E. S. Williams Age-related lesions in laboratory-confined raccoons (Procyon lotor) inoculated with the agent of chronic wasting disease of mule deer J Vet Diagn Invest, November 1, 2007; 19(6): 680 - 686. [Abstract] [Full Text] [PDF]

				J. J. Greenlee, A. N. Hamir, and M. H. West Greenlee Abnormal prion accumulation associated with retinal pathology in experimentally inoculated scrapie-affected sheep. Vet. Pathol., September 1, 2006; 43(5): 733 - 739. [Abstract] [Full Text] [PDF]