Submitted to: United States Animal Health Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/20/2004
Publication Date: 10/22/2004
Citation: Richt, J.A., Kluge, J.P., Alt, D.P., Kunkle, R.A., Hamir, A.N., Czub, S., Davis, A.J., Hall, S.M. 2004. Characterization of the recent U.S. BSE case and methods for surveillance. In: Proceedings of the 108th Annual Meeting of the United States Animal Health Association, October 22-27, 2004, Greensboro, North Carolina. p. 91-92. Interpretive Summary:
Technical Abstract: Bovine spongiform encephalopathy (BSE) is a transmissible spongiform encephalopathy of cattle, first detected in 1986 in the U.K. and subsequently in other countries. Here we report on the prion protein polypeptide profile and genotype from the first case of BSE diagnosed in the United States. The six-year old Holstein cow, imported into the State of Washington from Canada in 2001, was nonambulatory at slaughter. The formalin-fixed obex area of the brainstem was found to contain spongiform changes by histopathology and extensive deposition of the abnormal form of the prion protein, PrPres, by immunohistochemistry. Western blot analyses and an enzyme-linked immunosorbent assay using brainstem and cerebellum derived from fresh tissue from the suspect animal revealed positive results. Comparison of the U.S. BSE isolate to the Canadian BSE isolate and European BSE isolates showed similar sized PrPres polypeptide fragments. In addition, the PrP gene from the U.S. BSE case was found to be of bovine origin with a normal cattle PrP sequence. We conclude from these studies that the PrPres profile from the first BSE case diagnosed in the U.S. showed similar molecular properties to the typical PrPres pattern described for the earlier Canadian and European BSE isolates, and that a germline mutation in the bovine PrP gene was not evident. In addition, the sampling and testing methods implemented for the enhanced surveillance program for BSE in the United States will be discussed.