ZusammenfassungScrapie bei Schafen und Ziegen ist seit mehr als 250 Jahren bekannt. Dennoch rückte die Gruppe der transmissiblen spongiformen Enzephalopathien (TSE) erst nach dem Auftreten der bovinen spongiformen Enzephalopathie (BSE) im Vereinigten Königreich Ende der 1980er Jahre und dem einige Jahre später geführten Nachweis der übertragbarkeit des BSE-Erregers auf den Menschen in den 1990er Jahren vermehrt in das wissenschaftliche und öffentliche Interesse.Weltweit wurden mehr als 180000 BSE-Fälle bei Rindern diagnostiziert, davon die überwiegende Zahl im Vereinigten Königreich. Diese massive Infektion von Tieren mit dem BSE-Erreger erfolgte durch die unzureichende Inaktivierung und Verfütterung kontaminierter Futtermittel tierischen Ursprungs. Angesichts der seit 2001 zurückgehenden Zahl von BSE-Fällen in der gesamten EU und seit 2002 auch in Deutschland scheint das BSE-Geschehen bei Rindern heute unter Kontrolle. Anders verhält es sich mit den Scrapie-Fällen bei kleinen Wiederkäuern, deren endemische Verbreitung in den meisten EU-Mitgliedsstaaten durch die Einführung eines aktiven überwachungsprogramms aufgedeckt wurde. Dieses Programm führte auch zur Feststellung so genannter atypischer Scrapiefälle. Atypische Scrapie-Ausbrüche wurden bis dato in fast allen EU-Mitgliedsstaaten und zahlenmäßig häufiger als klassische Scrapie-Ausbrüche diagnostiziert. Daneben wurden mittlerweile auch zwei weitere BSE-Typen gefunden, die sich von den vom Vereinigten Königreich ausgangenen Fällen unterscheiden. Dieser Artikel fasst die aktuellen Erkenntnisse zur Epidemiologie, Pathogenese und Diagnostik von Scrapie und BSE zusammen.

Ausgehend von der retrospektiven Betrachtung des Vorkommens von klassischen und atypischen BSE-Fällen wird die Fallzahlentwicklung zusammen mit den im Rahmen des gesundheitlichen Verbraucherschutzes durchgeführten Maßahmen beleuchtet. Dieser Ansatz ermöglicht die Identifizierung der Maßnahmen, die wesentlich zur Verringerung der BSE-Fälle beigetragen haben könnten. Durch diese Identifizierung wird es möglich, die zurzeit diskutierten Vorschläge zur Änderung der Maßnahmen zu qualifizieren.

Animal GeneticsVolume 38, Issue 1 p. 88-89 Microsatellites MCMA53 and MCMA16 on OAR15 are associated with susceptibility to atypical scrapie G. Lühken, G. Lühken Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorD. Zieleniewicz, D. Zieleniewicz Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorH. R. Brandt, H. R. Brandt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorA. Buschmann, A. Buschmann Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institute (FLI), Insel Riems, GermanySearch for more papers by this authorM. H. Groschup, M. H. Groschup Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institute (FLI), Insel Riems, GermanySearch for more papers by this authorG. Erhardt, G. Erhardt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this author G. Lühken, G. Lühken Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorD. Zieleniewicz, D. Zieleniewicz Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorH. R. Brandt, H. R. Brandt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorA. Buschmann, A. Buschmann Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institute (FLI), Insel Riems, GermanySearch for more papers by this authorM. H. Groschup, M. H. Groschup Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institute (FLI), Insel Riems, GermanySearch for more papers by this authorG. Erhardt, G. Erhardt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this author First published: 11 January 2007 https://doi.org/10.1111/j.1365-2052.2006.01552.xCitations: 2 G. Lühken (gesine.luehken@agrar.uni-giessen.de) Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume38, Issue1February 2007Pages 88-89 RelatedInformation

Intensive active surveillance has uncovered two atypical German BSE cases in older cattle which resemble the two different atypical BSE phenotypes that have recently been described in France (designated H-type) and Italy (designated L-type or BASE). The H-type is characterized by a significantly higher molecular size, but a conventional glycopattern of the proteinase K treated abnormal prion protein (PrPSc), while the L-type PrPSc has only a slightly lower molecular size and a distinctly different glycopattern. In this paper we describe the successful transmission of both German atypical BSE cases to transgenic mice overexpressing bovine PrPC. Upon challenge with the L-type, these mice developed BSE after a substantially shorter incubation period than any classical BSE transmission using these mice to date. In contrast, the incubation period was distinctly prolonged when these mice were challenged with the H-type. PrPSc accumulated in the brains of these mice were of the same atypical BSE type that had been used for the transmission. These atypical cases suggest the possible existence of sporadic BSE cases in bovines. It is thus feasible that the BSE epidemic in the UK could have also been initiated by an intraspecies transmission from a sporadic BSE case.

Animal GeneticsVolume 37, Issue 4 p. 426-427 Microsatellite CTSBJ12 is located distal to the ovine prion protein gene on OAR13 and is not associated with scrapie susceptibility G. Lühken, G. Lühken Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorH. R. Brandt, H. R. Brandt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorA. Buschmann, A. Buschmann Friedrich-Loeffler-Institute (FLI), Institute for Novel and Emerging Infectious Diseases, Insel Riems, GermanySearch for more papers by this authorM. H. Groschup, M. H. Groschup Friedrich-Loeffler-Institute (FLI), Institute for Novel and Emerging Infectious Diseases, Insel Riems, GermanySearch for more papers by this authorG. Erhardt, G. Erhardt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this author G. Lühken, G. Lühken Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorH. R. Brandt, H. R. Brandt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this authorA. Buschmann, A. Buschmann Friedrich-Loeffler-Institute (FLI), Institute for Novel and Emerging Infectious Diseases, Insel Riems, GermanySearch for more papers by this authorM. H. Groschup, M. H. Groschup Friedrich-Loeffler-Institute (FLI), Institute for Novel and Emerging Infectious Diseases, Insel Riems, GermanySearch for more papers by this authorG. Erhardt, G. Erhardt Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, GermanySearch for more papers by this author First published: 20 June 2006 https://doi.org/10.1111/j.1365-2052.2006.01465.xCitations: 2 G. Lühken (e-mail: [email protected]) Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume37, Issue4August 2006Pages 426-427 RelatedInformation

The prion theory postulates that prions are novel infectious agents that are composed largely, if not entirely, of abnormally folded host-encoded prion proteins. However, the existence of different prion strains is enigma, if these novel infectious agents lack a genetic element, such as a nucleic acid. The best proof for this 'protein-only' concept would be the in vitro generation of prions from synthetic sources. Indeed, a substantial body of evidence has meanwhile been accumulated in favour of this postulate. This mini review recapitulates all relevant studies and experimental data on the generation of synthetic prions.

The term of 'TSE infections in small ruminants' summarises BSE as well as classical and the recently discovered atypical scrapie infections in sheep and goats. There are fundamental differences between the TSE infections in small and large ruminants. Other than in bovines the TSE pathogenesis in small ruminants implies that various peripheral tissues become infectious long before the onset of clinical symptoms. At least in sheep, classical scrapie is efficiently transmitted horizontally within affected flocks. On the other hand, BSE poses a distinctly higher zoonotic risk than scrapie. Therefore, regulatory measures for the protection of animals and humans from a BSE infection must be substantially different for large and small ruminants. While culling of the birth and feeding cohort of a BSE affected cattle is considered to be effective to prevent any further BSE cases in the affected herd, an effective BSE and classical scrapie eradication programme in small ruminants requires a much more stringent eradication strategy and the rendering of all susceptible animals. The situation became even more complicated when atypical scrapie cases with divergent transmission and pathogenesis characteristics and with a novel biochemical phenotype of the infectious agent came into play. The discovery of these atypical scrapie cases has initiated a discussion about the suitability of the current TSE eradication measures in sheep (which are selective breeding and genotype based culling), in particular when such cases were also found in sheep carrying the believed scrapie resistant genotypes.

Following the implementation of a large scale transmissible spongiform encephalopathies (TSE) surveillance programme of small ruminants, evidence for a natural transmission of bovine spongiform encephalopathy (BSE) to a French goat has been found. During the years 2002-2004, a massive TSE rapid testing programme on >250,000 small ruminants was carried out in Germany. In this national survey, 186 scrapie-affected sheep were found which originated from 78 flocks. The majority of these cases were of the classical TSE type (115 sheep belonging to 14 outbreaks). However, 71 cases coming from 64 flocks were of the novel atypical scrapie type. According to the regulation EU 999/2001, all TSE cases in small ruminants have to be examined by strain typing methods to explore any possibility of the existence of BSE cases in the field sheep population. Here we report on a biochemical typing strategy (termed FLI-test), which includes the determination of molecular masses, antibody binding affinities and glycosylation pattern of the TSE induced abnormal prion protein. Based on this typing approach none of the analysed German classical TSE outbreaks (total number of analysed sheep: 36) displayed biochemical features indicative for a BSE infection. However, in two cases distinct but BSE-unrelated PrP(Sc) types were found, which alludes to the existence of different scrapie strains in the German sheep population.

Transgenic mice expressing bovine prion protein (PrP)(C) (Tgbov XV mice) display remarkably shorter incubation times for cattle-derived bovine spongiform encephalopathy (BSE) infectivity than do nontransgenic mice. To verify that this phenomenon reflects increased sensitivity, we challenged Tgbov XV mice and conventional RIII mice with a BSE brain-stem homogenate of known infectivity titer in cattle. An end-point titration experiment in Tgbov XV mice revealed their superior sensitivity, which exceeded that of RIII mice by at least 10,000-fold and even that of cattle by similar to 10-fold. Moreover, Tgbov XV mice were challenged with various tissues from cattle with end-stage clinical BSE, and infectivity was found only in the central and peripheral nervous system and not in lymphatic tissues; the only exception was the Peyer's patches of the distal ileum, which most likely are the site of entry for BSE infectivity. These results provide further indication that the pathogenesis of BSE in cattle is fundamentally different from that in sheep and mice, due to an exclusive intraneuronal spread of infectivity from the gut to the central nervous system.

Prion protein (PrP) genotypes were determined in eight sheep that have been tested positive for atypical scrapie from purebred or crossbred Merinoland sheep flocks in Germany and compared with the PrP genotypes of their flock mates. Two restriction fragment length polymorphism (RFLP) analyses were developed to determine all PRNP haplotypes occurring by variations at codons 136, 154 and 171. At least one copy of the A(136) H(154) Q(171) (AHQ) allele was found in all scrapie-positive sheep while the frequency of AHQ varied from over 23% to less than 3% in the whole flocks. There was a significant association between PrP genotype and a positive scrapie diagnosis over all flocks, suggesting a high scrapie susceptibility of PrP genotypes including the AHQ allele, at least in sheep of Merinoland type. These results argue that sheep with the AHQ allele are not generally less susceptible to scrapie and support the hypothesis that the influence of this allele on scrapie susceptibility may vary from flock to flock depending on genetic and/or epidemiological factors. This has to be considered when strategies for the eradication of scrapie in sheep are based on PrP genotypes.

The conversion of cellular prion protein (PrP(C)) into its pathological isoform (PrP(Sc)) conveys an increase in hydrophobicity and induces a partial resistance to proteinase K (PK). Interestingly, co-incubation with high copper ion concentrations also modifies the solubility of PrP(c) and induces a partial PK resistance which was reminiscent of PrP(Sc). However, concerns were raised whether this effect was not due to a copper-induced inhibition of the PK itself. We have therefore analyzed the kinetics of the formation of PK-resistant PrP(C) and excluded possible interference effects by removing unbound copper ions prior to the addition of PK by methanol precipitation or immobilization of PrP(C) followed by washing steps. We found that preincubation of PrPc with copper ions at concentrations as low as 50 microM indeed rendered these proteins completely PK resistant, while control substrates were proteolyzed. No other divalent cations induced a similar effect. However, in addition to this specific stabilizing effect on PrP(C), higher copper ion concentrations in solution (>200 microM) directly blocked the enzymatic activity of PK, possibly by replacing the Ca2+ ions in the active center of the enzyme. Therefore, as a result of this inhibition the proteolytic degradation of PrP(C) as well as PrP(Sc) molecules was suppressed.

The susceptibility of sheep to scrapie infection is influenced by prion gene alleles, which are modulated by polymorphic variations corresponding to amino acid positions 136, 154 and 173 of the prion protein (PrP). As no unquestioned report of a diseased sheep carrying homozygous alleles encoding alanine, arginine and arginine (Prp(ARR)) at these sites has been published to date, sheep of this genotype are believed to be scrapie resistant. After the introduction of large-scale rapid testing for scrapie, a number of so-called 'atypical' scrapie cases have been found in Germany and elsewhere. Among those cases were two supposedly scrapie- resistant sheep. Brain samples from these animals tested positive for abnormal PrP (PrPSc) in one of four rapid tests available. Moreover, scrapie-associated fibril (SAF)-immunoblotting and immunohistochemistry, which are the generally accepted diagnostic techniques for scrapie, revealed prominent PrPSc deposition in the cerebellum. SAF immunoblotting also revealed PrPsc deposition in the obex, frontal cortex and brainstem. Transmission experiments to investigate the infectivity of scrapie propagated from these sheep have been initiated.

The intensified surveillance of scrapie in small ruminants in the European Union (EU) has resulted in a substantial increase of the number of diagnosed cases. Four rapid tests which have passed the EU evaluation for BSE testing of cattle are also recommended currently and used for the testing of small ruminants by the EU authorities. These tests include an indirect ELISA (cELISA), a colorimetric sandwich ELISA (sELISA I), a chemiluminescent sandwich ELISA (sELISA II), and a Western blot (WB). To this point, the majority of samples have been screened by using either sELISA I (predominantly in Germany) or WB (predominantly in France). In this study, it is shown that a number of the German and French scrapie cases show inconsistent results using rapid and confirmatory test methods. Forty-eight German sheep, 209 French sheep and 19 French goat transmissible spongiform encephalopathy (TSE) cases were tested. All cases were recognised by the sELISA I and either one of the confirmatory methods (scrapie-associated fibrils (SAF)-immunoblot or immunohistochemistry). Surprisingly, three rapid tests failed to detect a significant number of scrapie cases (29 in France and 24 in Germany). The possible reasons for these inconsistent reaction patterns of scrapie cases are discussed. Similar discrepancies have not been observed during rapid testing of cattle for BSE, the disease for which all diagnostic methods applied have been evaluated.

We here report on the first case of scrapie in Bavaria. The post mortem of a six year old ewe of the breed German grey Heath with a suspected subclinical calcinosis revealed typical histopathological signs of a spongiform encephalopathy aid immunohistochemistry was positive for PrPSc in the cervical part of the spinal cord. Eight out of 18 sheep of the herd showed clinical symptoms.

The susceptibility of sheep to scrapie is known to involve, as a major determinant, the nature of the prion protein (PrP) allele, with the VRQ allele conferring the highest susceptibility to the disease, Transgenic mice expressing in their brains three different ovine PrP(VRQ)-encoding transgenes under an endogenous PrP-deficient genetic background were established, Nine transgenic (tgOv) lines were selected and challenged with two scrapie field isolates derived from VRQ-homozygous affected sheep, All inoculated mice developed neurological signs associated with a transmissible spongiform encephalopathy (TSE) disease and accumulated a protease-resistant form of PrP (PrPres) in their brains. The incubation duration appeared to be inversely related to the PrP steady-state level in the brain, irrespective of the transgene construct. The survival time for animals from the line expressing the highest level of PrP was reduced by at least 1 year compared to those of two groups of conventional mice. With one isolate, the duration of incubation was as short as 2 months, which is comparable to that observed for the rodent TSE models with the briefest survival times. No survival time reduction was observed upon subpassaging of either isolate, suggesting no need for adaptation of the agent to its new host, Overexpression of the transgene was found not to be required for transmission to be accelerated compared to that observed with wild-type mice. Conversely, transgenic mice overexpressing murine PrP were found to be less susceptible than tgOv lines expressing ovine PrP at physiological levels. These data argue that ovine PrP(VRQ) provided a better substrate for sheep prion replication than did mouse PrP. Altogether, these tgOv mice could be an improved model for experimental studies on natural sheep scrapie.