Richt Jürgen A, Kunkle Robert A, Alt David, Nicholson Eric M, Hamir Amir N, Czub Stefanie, Kluge John, Davis Arthur J, Hall S Mark
Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, Iowa 50010, USA.
J Vet Diagn Invest. 2007 Mar;19(2):142-54. doi: 10.1177/104063870701900202.
Bovine spongiform encephalopathy (BSE) is a transmissible spongiform encephalopathy of cattle, first detected in 1986 in the United Kingdom and subsequently in other countries. It is the most likely cause of variant Creutzfeldt-Jakob disease (vCJD) in humans, but the origin of BSE has not been elucidated so far. This report describes the identification and characterization of two cases of BSE diagnosed in the United States. Case 1 (December 2003) exhibited spongiform changes in the obex area of the brainstem and the presence of the abnormal form of the prion protein, PrP(Sc), in the same brain area, by immunohistochemistry (IHC) and Western blot analysis. Initial suspect diagnosis of BSE for case 2 (November 2004) was made by a rapid ELISA-based BSE test. Case 2 did not exhibit unambiguous spongiform changes in the obex area, but PrP(Sc) was detected by IHC and enrichment Western blot analysis in the obex. Using Western blot analysis, PrP(Sc) from case 1 showed molecular features similar to typical BSE isolates, whereas PrP(Sc) from case 2 revealed an unusual molecular PrP(Sc) pattern: molecular mass of the unglycosylated and monoglycosylated isoform was higher than that of typical BSE isolates and case 2 was strongly labeled with antibody P4, which is consistent with a higher molecular mass. Sequencing of the prion protein gene of both BSE-positive animals revealed that the sequences of both animals were within [corrected] the range of the prion protein gene sequence diversity previously reported for cattle.
牛海绵状脑病（BSE）是一种牛的传染性海绵状脑病，1986年首次在英国被发现，随后在其他国家也有发现。它是人类变异型克雅氏病（vCJD）最可能的病因，但BSE的起源至今尚未阐明。本报告描述了在美国诊断出的两例BSE病例的鉴定和特征。病例1（2003年12月）通过免疫组织化学（IHC）和蛋白质印迹分析，在脑干的闩部区域表现出海绵状变化，并在同一脑区检测到异常形式的朊病毒蛋白PrP(Sc)。病例2（2004年11月）最初通过基于ELISA的快速BSE检测被怀疑诊断为BSE。病例2在闩部区域未表现出明确的海绵状变化，但通过IHC和富集蛋白质印迹分析在闩部检测到PrP(Sc)。使用蛋白质印迹分析，病例1的PrP(Sc)显示出与典型BSE分离株相似的分子特征，而病例2的PrP(Sc)则显示出异常的分子PrP(Sc)模式：未糖基化和单糖基化异构体的分子量高于典型BSE分离株，并且病例2被抗体P4强烈标记，这与较高的分子量一致。对两例BSE阳性动物的朊病毒蛋白基因进行测序，结果显示这两只动物的序列均在先前报道的牛朊病毒蛋白基因序列多样性范围内[已校正]。
