101
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Manson JC, Cancellotti E, Hart P, Bishop MT, Barron RM. The transmissible spongiform encephalopathies: emerging and declining epidemics. Biochem Soc Trans 2007; 34:1155-8. [PMID: 17073774 DOI: 10.1042/bst0341155] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TSEs (transmissible spongiform encephalopathies) are neurodegenerative diseases of various mammalian species, the best known of which include BSE (bovine spongiform encephalopathies) in cattle, CJD (Creutzfeldt-Jakob disease) in humans, scrapie in sheep and CWD (chronic wasting disease) in deer. This review examines the emergence of various TSE strains and their transmission, and discusses disease surveillance and control.
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Affiliation(s)
- J C Manson
- Institute for Animal Health, Neuropathogenesis Unit, Ogston Building, West Mains Road, Edinburgh EH9 3JF, Scotland, UK.
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102
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Konold T, Davis A, Bone G, Bracegirdle J, Everitt S, Chaplin M, Saunders GC, Cawthraw S, Simmons MM. Clinical findings in two cases of atypical scrapie in sheep: a case report. BMC Vet Res 2007; 3:2. [PMID: 17298670 PMCID: PMC1810526 DOI: 10.1186/1746-6148-3-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Accepted: 02/13/2007] [Indexed: 12/03/2022] Open
Abstract
Background Atypical scrapie is a recently recognised form of transmissible spongiform encephalopathy of sheep that differs from classical scrapie in its neuropathological and biochemical features. Most cases are detected in apparently healthy sheep and information on the clinical presentation is limited. Case presentation This report describes the clinical findings in two sheep notified as scrapie suspects and confirmed as atypical scrapie cases by immunohistochemistry and Western immunoblotting. Although both sheep displayed signs suggestive of a cerebellar dysfunction there was considerable variation in the individual clinical signs, which were similar to classical scrapie. Conclusion Any sheep presenting with neurological gait deficits should be assessed more closely for other behavioural, neurological and physical signs associated with scrapie and their presence should lead to the suspicion of scrapie.
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Affiliation(s)
- Timm Konold
- Neuropathology, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
- Royal Veterinary College, Population Biology and Disease Control Research Group, North Mymms, Hatfield, UK
| | - Andrew Davis
- Neuropathology, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
| | - Gemma Bone
- Neuropathology, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
| | | | - Sharon Everitt
- TSE Molecular Biology 4, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
| | - Melanie Chaplin
- TSE Molecular Biology 4, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
| | - Ginny C Saunders
- TSE Molecular Biology 4, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
| | - Saira Cawthraw
- TSE Molecular Biology 4, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
| | - Marion M Simmons
- Neuropathology, Veterinary Laboratories Agency Weybridge, New Haw, Addlestone, UK
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103
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Thackray A, Hopkins L, Bujdoso R. Proteinase K-sensitive disease-associated ovine prion protein revealed by conformation-dependent immunoassay. Biochem J 2007; 401:475-83. [PMID: 17018021 PMCID: PMC1820801 DOI: 10.1042/bj20061264] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PrPSc [abnormal disease-specific conformation of PrP (prion-related protein)] accumulates in prion-affected individuals in the form of amorphous aggregates. Limited proteolysis of PrPSc results in a protease-resistant core of PrPSc of molecular mass of 27-30 kDa (PrP27-30). Aggregated forms of PrP co-purify with prion infectivity, although infectivity does not always correlate with the presence of PrP27-30. This suggests that discrimination between PrPC (normal cellular PrP) and PrPSc by proteolysis may underestimate the repertoire and quantity of PrPSc subtypes. We have developed a CDI (conformation-dependent immunoassay) utilizing time-resolved fluorescence to study the conformers of disease-associated PrP in natural cases of sheep scrapie, without using PK (proteinase K) treatment to discriminate between PrPC and PrPSc. The capture-detector CDI utilizes N-terminal- and C-terminal-specific anti-PrP monoclonal antibodies that recognize regions of the prion protein differentially buried or exposed depending on the extent of denaturation of the molecule. PrPSc was precipitated from scrapie-infected brain stem and cerebellum tissue following sarkosyl extraction, with or without the use of sodium phosphotungstic acid, and native and denatured PrPSc detected by CDI. PrPSc was detectable in brain tissue from homozygous VRQ (V136 R154 Q171) and ARQ (A136 R154 Q171) scrapie-infected sheep brains. The highest levels of PrPSc were found in homozygous VRQ scrapie-infected brains. The quantity of PrPSc was significantly reduced, up to 90% in some cases, when samples were treated with PK prior to the CDI. Collectively, our results show that the level of PrPSc in brain samples from cases of natural scrapie display genotypic differences and that a significant amount of this material is PK-sensitive.
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Affiliation(s)
- Alana M. Thackray
- Centre for Veterinary Science, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, U.K
| | - Lee Hopkins
- Centre for Veterinary Science, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, U.K
| | - Raymond Bujdoso
- Centre for Veterinary Science, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, U.K
- To whom correspondence should be addressed (email )
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104
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Gretzschel A, Buschmann A, Langeveld J, Groschup MH. Immunological characterization of abnormal prion protein from atypical scrapie cases in sheep using a panel of monoclonal antibodies. J Gen Virol 2006; 87:3715-3722. [PMID: 17098989 DOI: 10.1099/vir.0.81816-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
After the implementation of an active surveillance programme for scrapie in sheep in the EU, the number of diagnosed classical scrapie cases rose sharply and a novel kind of so-called atypical scrapie case was discovered. These atypical scrapie cases display unusual features concerning the distribution of the abnormal prion protein (PrP(Sc)) in the brain, a distinct electrophoretic profile of PrP(Sc) and an inconsistent reaction pattern in the currently used rapid tests. In this report, PrP(Sc) of two German atypical sheep scrapie cases was characterized by epitope mapping using a panel of 18 monoclonal antibodies that were directed against epitopes located throughout the prion protein. This analysis suggests that PrP(Sc) derived from atypical scrapie cases and treated with proteinase K is largely composed of an 11 kDa fragment (previously referred to as the 12 kDa band) and of polymeric fragments thereof. The 11 kDa band corresponds to a prion protein fragment spanning approximately aa 90-153 and may therefore represent a novel PrP(Sc) type.
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Affiliation(s)
- Anja Gretzschel
- Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut, Boddenblick 5a, 17493 Greifswald-Insel Riems, Germany
| | - Anne Buschmann
- Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut, Boddenblick 5a, 17493 Greifswald-Insel Riems, Germany
| | - Jan Langeveld
- Central Institute for Animal Disease Control, PO Box 2004, 8203 AA Lelystad, The Netherlands
| | - Martin H Groschup
- Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut, Boddenblick 5a, 17493 Greifswald-Insel Riems, Germany
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105
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Lühken G, Buschmann A, Brandt H, Eiden M, Groschup MH, Erhardt G. Epidemiological and genetical differences between classical and atypical scrapie cases. Vet Res 2006; 38:65-80. [PMID: 17156738 DOI: 10.1051/vetres:2006046] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Accepted: 09/13/2006] [Indexed: 11/15/2022] Open
Abstract
The aim of this study was to analyze the epidemiology and prion protein (PrP) genetics in scrapie-affected sheep flocks in Germany. For this purpose, 224 German scrapie cases in sheep diagnosed between January 2002 and February 2006 were classified as classical or atypical scrapie and the amino acids at codons 136, 141, 154 and 171 were determined. Likewise, representative numbers of flock mates were genotyped. Significant epidemiological differences were observed between classical and atypical scrapie cases in regard to the numbers of scrapie-affected sheep within a flock, the sizes of flocks with only a single scrapie-positive sheep or more than one scrapie-positive sheep and the age distribution of the scrapie-positive sheep. Sheep with the ARQ/ARQ genotype had by far the highest risk for acquiring classical scrapie, but the risk for atypical scrapie was the highest for sheep carrying phenylalanine (F) at position 141 (AF(141)RQ) and/or the AHQ haplotype. However, atypical scrapie also occurred with a notable frequency in sheep with the PrP haplotypes ARR and/or ARQ in combination with Leucine at position 141 (AL(141)RQ). Furthermore, six atypical scrapie-positive sheep carried the PrP genotype ARR/ARR. The high proportion of sheep flocks affected by atypical scrapie underscores the importance of this scrapie type.
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Affiliation(s)
- Gesine Lühken
- Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, Germany.
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106
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Ronzon F, Bencsik A, Lezmi S, Vulin J, Kodjo A, Baron T. BSE inoculation to prion diseases-resistant sheep reveals tricky silent carriers. Biochem Biophys Res Commun 2006; 350:872-7. [PMID: 17049491 DOI: 10.1016/j.bbrc.2006.09.137] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Accepted: 09/21/2006] [Indexed: 11/28/2022]
Abstract
The possible transmission of bovine spongiform encephalopathy (BSE) agent to sheep contributed to select genetically sheep considered as resistant to prion diseases i.e., with PrP ARR/ARR genotype. Here, we report the infection of two PrP ARR/ARR genotype sheep using the cattle BSE agent inoculated by peripheral routes. Disease-associated prion protein (PrP(d)) was detected in the brain for one case (at 2191 days post-infection (dpi)) and only in the nervous enteric system for the other one (at 673dpi). The electrophoretic pattern of PrP(d) from the obex region in this BSE challenged sheep was shown to be closer from that found in naturally scrapie-affected sheep with regard to the apparent molecular mass of the unglycosylated PrP(d). Importantly, the absence of any clinical symptoms up to 6 years following experimental challenge suggests that silent carriers of the BSE agent may exist among ARR homozygous sheep.
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Affiliation(s)
- Frédéric Ronzon
- Agence Française de Sécurité Sanitaire des Aliments (AFSSA), Unité ATNC, 31 avenue Tony Garnier, 69364 LYON cedex 07, France
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107
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Hopp P, Omer MK, Heier BT. A case–control study of scrapie Nor98 in Norwegian sheep flocks. J Gen Virol 2006; 87:3729-3736. [PMID: 17098991 DOI: 10.1099/vir.0.81951-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Scrapie is a fatal, neurological disease of sheep and goats and belongs to the transmissible spongiform encephalopathies. In 1998, a new type of scrapie, designated scrapie Nor98, was detected in Norway. Scrapie Nor98 differs from classical scrapie in the distribution of pathological changes and of the scrapie prion protein, the Western blot profile of the prion protein, and with isolated cases usually being observed in the case flocks. In 2004, a case–control study was conducted on scrapie Nor98 with 28 cases and 102 randomly selected controls. The questionnaire included questions on demographic data, animal contact between sheep flocks, indirect contact with equipment, use of concentrate feed and supplemental feeds, and use of medicines and vaccines. The data were analysed by using logistic regression with the sheep flock as the statistical unit. In the final model, the detection of scrapie Nor98 was related to the practice of not removing all afterbirths, the use of vitamin and mineral feed supplements, the absence of concentrate feed of swine or poultry on the farm and the presence of dogs on the farm. The results show that the epidemiology of scrapie Nor98 differs from that of classical scrapie in that no risk factors that indicate transmission of scrapie Nor98 between flocks by movement or direct contact between animals were found. Furthermore, the association between scrapie Nor98 and mineral intake shown herein should be explored further. Although the possibility that scrapie Nor98 has a low transmissibility between animals under natural conditions cannot be ruled out, the results would also be in accordance with a spontaneous aetiology.
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Affiliation(s)
- Petter Hopp
- National Veterinary Institute, PO Box 8156 Dep, NO-0033 Oslo, Norway
| | - Mohamed K Omer
- National Veterinary Institute, PO Box 8156 Dep, NO-0033 Oslo, Norway
| | - Berit T Heier
- National Veterinary Institute, PO Box 8156 Dep, NO-0033 Oslo, Norway
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108
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Abstract
Prions cause fatal and transmissible neurodegenerative disease. These etiological infectious agents are formed in greater part from a misfolded cell-surface protein called PrP(C). Several mammalian species are affected by the diseases, and in the case of "mad cow disease" (BSE) the agent has a tropism for humans, with negative consequences for agribusiness and public health. Unfortunately, the known universe of prion diseases is expanding. At least four novel prion diseases--including human diseases variant Creutzfeldt-Jakob disease (vCJD) and sporadic fatal insomnia (sFI), bovine amyloidotic spongiform encephalopathy (BASE), and Nor98 of sheep--have been identified in the last ten years, and chronic wasting disease (CWD) of North American deer (Odocoileus Specis) and Rocky Mountain elk (Cervus elaphus nelsoni) is undergoing a dramatic spread across North America. While amplification (BSE) and dissemination (CWD, commercial sourcing of cervids from the wild and movement of farmed elk) can be attributed to human activity, the origins of emergent prion diseases cannot always be laid at the door of humankind. Instead, the continued appearance of new outbreaks in the form of "sporadic" disease may be an inevitable outcome in a situation where the replicating pathogen is host-encoded.
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Affiliation(s)
- Joel C Watts
- Centre for Research in Neurodegenerative Diseases and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
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109
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Saunders GC, Cawthraw S, Mountjoy SJ, Hope J, Windl O. PrP genotypes of atypical scrapie cases in Great Britain. J Gen Virol 2006; 87:3141-3149. [PMID: 17030846 DOI: 10.1099/vir.0.81779-0] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Great Britain and elsewhere have detected atypical scrapie infection in sheep with PrP genotypes thought to be genetically resistant to the classical form of scrapie. DNA sequencing of the PrP gene of British atypical scrapie cases (n=69), classical scrapie cases (n=59) and scrapie-free controls (n=138) was undertaken to identify whether PrP variants, other than the three well-characterized polymorphic codons, influenced susceptibility to atypical scrapie infection. Four non-synonymous changes, M112T, M137T, L141F and P241S, were detected that are most probably associated with the A(136)R(154)Q(171) haplotype. Only the PrP variant containing a phenylalanine residue at amino acid position 141 was found to be associated more commonly with the atypical scrapie cases. In addition to the single nucleotide polymorphisms associated with the ARQ allele, two out of nine atypical scrapie cases with the ARR/ARR genotype were found to contain a 24 bp insertion, leading to an additional octapeptide repeat. In terms of PrP genetics, one classification of the GB scrapie cases examined in this study would place animals carrying any homozygous or heterozygous combination of ARR, AHQ or AF(141)RQ alleles, or any one of these alleles when paired with ARQ, as being susceptible to atypical scrapie infection, and animals heterozygous or homozygous for VRQ or homozygous for ARQ as being susceptible to classical scrapie disease. The AHQ PrP allele was associated with the highest incidence of atypical scrapie (263 per 100 000 alleles), whilst VRQ was associated with the lowest incidence (10 per 100 000 alleles).
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Affiliation(s)
- G C Saunders
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - S Cawthraw
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - S J Mountjoy
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - J Hope
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - O Windl
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
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110
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Baron T, Biacabe AG, Arsac JN, Benestad S, Groschup MH. Atypical transmissible spongiform encephalopathies (TSEs) in ruminants. Vaccine 2006; 25:5625-30. [PMID: 17126958 DOI: 10.1016/j.vaccine.2006.10.058] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 10/30/2006] [Indexed: 11/22/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs) are associated with the accumulation in infected tissues of a disease-associated form of a host-encoded protein, the prion protein (PrP). Contrary to the normal form of the protein, this form of PrP is partially resistant to protease digestion (PrP(res)). Detailed characterisation of PrP(res) has been intensively investigated in recent years to try and decipher the diversity of TSEs in human and animals. This considerably and unexpectedly enlarged our knowledge about such diseases in ruminants. Previously, such a diversity was essentially shown by the demonstration that scrapie from sheep and goats could have different biological behaviours following transmission of the disease in mice, unlike bovine spongiform encephalopathy from cattle (BSE) which showed a distinct and unique behaviour. The properties of the BSE agent were also demonstrated to be very stable, following transmission to a variety of different species. Molecular studies of PrP(res), followed by transmission studies to mice, gave the first evidence for the accidental transmission of the BSE agent to humans where it induced a variant form of the fatal Creutzfeldt-Jakob disease (CJD) and also to different animal species including a goat in France. This last case was found among a few unusual cases of TSEs in small ruminants that showed some molecular similarities with BSE and which are currently under investigation by transmission studies in mice. The application of the molecular methods to characterise PrP(res) has most recently led to the unexpected discovery of deviant BSE forms in a few affected cattle in Europe and in the United States, which raises the question of a possible different origin at least of some cases of BSE in cattle. Finally, considerable numbers of a new TSE form in small ruminants, referred to as "atypical scrapie" or "Nor98", have meanwhile been identified in most European countries by TSE rapid testing using an assay which recognizes also comparatively less PK resistant PrP(res).
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Affiliation(s)
- T Baron
- AFSSA-Lyon, Unité ATNC, Lyon, France.
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111
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Lühken G, Brandt HR, Buschmann A, Groschup MH, Erhardt G. Microsatellite CTSBJ12 is located distal to the ovine prion protein gene on OAR13 and is not associated with scrapie susceptibility. Anim Genet 2006; 37:426-7. [PMID: 16879367 DOI: 10.1111/j.1365-2052.2006.01465.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- G Lühken
- Department of Animal Breeding and Genetics, Justus-Liebig University of Giessen, 35390 Giessen, Germany.
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112
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Molina A, Juárez M, Rodero A. Merino sheep breed's genetic resistance to Scrapie: Genetic structure and comparison of five eradication strategies. Prev Vet Med 2006; 75:239-50. [PMID: 16730818 DOI: 10.1016/j.prevetmed.2006.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2004] [Revised: 02/13/2006] [Accepted: 04/18/2006] [Indexed: 10/24/2022]
Abstract
Three thousand one hundred and ninety-three Merino-breeding males were genotyped for Scrapie-resistance gene. They showed a high frequency of ARQ allele while VRQ allele frequency, linked to the highest susceptibility, was close to 0. Alleles linked to Scrapie-susceptibility frequencies have been studied in different Merino flocks. Most of the variability is intraflock, not interflock. In addition, there is an excess of heterozygotes due to crossbreeding or Wahlund effect. Five control and prevention strategies were studied: first genotyping males and females and eliminating VRQ carriers and ARQ/ARQ rams; second genotyping males and females and eliminating VRQ carriers; third genotyping males and eliminating VRQ carriers and ARQ/ARQ rams; fourth genotyping males and using only as breeders ARR/ARR, ARR/AHQ, AHQ/AHQ and ARQ/ARQ rams; fifth genotyping males and using only as breeders ARR/ARR, ARR/AHQ and AHQ/AHQ rams. They were simulated from allelic and genotypic frequencies to decide which animals had to be genotyped and which animals had to be eliminated due to their genotypes and risk levels. The third option, to genotype rams and to eliminate ARQ/ARQ and VRQ carriers, would be the best strategy to improve the resistance and would cause minimal cost and loss of animals.
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Affiliation(s)
- A Molina
- Department of Genetics, University of Córdoba, Edif, Gregor Mendel, Campus de Rabanales, Crtra, Madrid-Cádiz Km, 396-a, C.P. 14071 Córdoba, Spain.
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113
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Opinion of the Scientific Panel on biological hazards (BIOHAZ) on the Breeding programme for TSE resistance in sheep. EFSA J 2006. [DOI: 10.2903/j.efsa.2006.382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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114
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Alvarez L, Gutiérrez-Gil B, San Primitivo F, de la Fuente LF, Arranz JJ. Influence of Prion Protein Genotypes on Milk Production Traits in Spanish Churra Sheep. J Dairy Sci 2006; 89:1784-91. [PMID: 16606750 DOI: 10.3168/jds.s0022-0302(06)72247-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this work was to analyze the possible relationships between milk production traits and prion protein genotypes in Spanish Churra sheep. For this purpose, 2 analyses were carried out. First, an association study was performed of the prion protein genotypes of 12,533 Churra ewes and their milk yield, protein percentage, fat percentage, and somatic cell score as phenotypes, followed by a quantitative trait loci screening on the chromosome where the prion protein gene was located in this population. The latter analysis was carried out using 8 genetic markers (7 microsatellites and the prion protein genotypes) spanning ovine chromosome 13 using a daughter design. Regarding genotype frequencies, the most frequent allele was ARQ (75.90%), which linked with a high susceptibility to scrapie, followed by the resistant haplotype, ARR (18.16 %). The frequency of the most susceptible allele, VRQ, was around 1%. No evidence of association or linkage between prion protein genotypes and milk traits has been detected in Churra sheep. These results indicate that increasing the ARR frequency in Churra population will not have an adverse effect on selection for milk traits included in the breeding objectives. However, the low allele frequencies for ARR should be considered in the initial stages to prevent possible bottlenecks in future genetic progress.
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Affiliation(s)
- L Alvarez
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, 24071, León, Spain
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115
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Lan Z, Wang ZL, Liu Y, Zhang X. Prion protein gene (PRNP) polymorphisms in Xinjiang local sheep breeds in China. Arch Virol 2006; 151:2095-101. [PMID: 16622593 DOI: 10.1007/s00705-006-0758-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Accepted: 02/27/2006] [Indexed: 11/24/2022]
Abstract
Amino acid polymorphisms of the prion protein (PrP) gene (PRNP), particularly those occurring at codons 136, 154, and 171 have a significant influence on scrapie pathogenesis in many sheep breeds. We isolated blood samples from 222 sheep representing the eight main local sheep breeds in the Xinjiang Autonomous Region, the territory with the most abundant local sheep breeds in China, to identify the PRNP polymorphisms and to determine whether these breeds were at risk for developing scrapie. A new PRNP polymorphism encoding either glycine (G) or arginine (R) at codon 85 as well as eight previously reported polymorphisms at codons 101, 112, 127, 141, 146, 154, 171, and 189 in other sheep breeds were detected. Interestingly, the alanine (A)/V polymorphism at codon 136 was not observed in this study, all sheep being homozygous for A at this position. While the previously identified polymorphism of argine (R) or histidine (H) at codon 154 was detected, the H polymorphism was rare (2.25%). Four polymorphisms at codon 171 encoding glutamine (Q), R, H, or lysine (K) were detected. The predominant ARQ allele occurred at a high frequency of 77.48%, suggesting an increased risk of scrapie in Xinjiang Autonomous Region.
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Affiliation(s)
- Z Lan
- Life Sciences and Technology College, Ocean University of China, Qingdao, P.R. China
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116
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Schettler E, Steinbach F, Eschenbacher-Kaps I, Gerst K, Muessdoerffer F, Risch K, Streich WJ, Frölich K. Surveillance for prion disease in cervids, Germany. Emerg Infect Dis 2006; 12:319-22. [PMID: 16494763 PMCID: PMC3373103 DOI: 10.3201/eid1202.050970] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An active survey on transmissible spongiform encephalopathies was performed from 2002 to 2005 on 4,255 roe deer, 1,445 red deer, and 1,604 fallow deer in Germany. All cervids tested negative. This survey has been the largest in European wildlife and provides no evidence of prion diseases in free-living German cervids.
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117
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Gavier-Widén D, Stack MJ, Baron T, Balachandran A, Simmons M. Diagnosis of transmissible spongiform encephalopathies in animals: a review. J Vet Diagn Invest 2006; 17:509-27. [PMID: 16475509 DOI: 10.1177/104063870501700601] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Transmissible spongiform encephalopathies (TSEs) in animals include, among others, bovine spongiform encephalopathy (BSE), scrapie, chronic wasting disease, and atypical forms of prion diseases. Diagnosis of TSEs is based on identification of characteristic lesions or on detection of the abnormal prion proteins in tissues, often by use of their partial proteinase K resistance property. Correctly sampling of target tissues is of utmost importance as this has a considerable effect on test sensitivity. Most of the rapid or screening tests are based on ELISA or Western immunoblot (WB) analysis, and many are officially approved. Confirmatory testing is normally performed by use of histologic examination, immunohistochemical analysis, certain WB protocols, or detection of prion fibrils by use of electron microscopy (scrapie-associated fibril). The discriminatory methods for diagnostic use are mostly based on WB technology and provide initial identification of the prion strain, particularly for differentiation of BSE from scrapie in small ruminants. Definitive prion strain characterization is performed by use of bioassays, usually in mice. A burgeoning number of transgenic mice have been developed for TSE studies. Development of new tests with higher sensitivity and of more reliable diagnostic applications for live animals tested for food safety reasons is a rapidly developing field. Ultimately, the choice of a test for TSE diagnosis depends on the rationale for the testing.
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118
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Kobayashi Y, Kohno N, Wanibe S, Hirayasu K, Uemori H, Tagawa Y, Yokoyama T, Shinagawa M. A solid-phase immunoassay of protease-resistant prion protein with filtration blotting involving sodium dodecyl sulfate. Anal Biochem 2006; 349:218-28. [PMID: 16289444 DOI: 10.1016/j.ab.2005.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 10/03/2005] [Indexed: 10/25/2022]
Abstract
The precise diagnosis for bovine spongiform encephalopathy (BSE) is crucial for preventing new transmission to humans. Several testing procedures are reported for determining protease-resistant prion protein in various tissues as a major hallmark of prion diseases such as BSE, scrapie, and Creutzfeldt-Jakob disease. However, contamination of materials from tissues or degradation of the specimens sometimes disturbs the accuracy of the assay. Here, we have developed a novel method for solid-phase immunoassay of the disease-specific conformational isoform, PrP(Sc), using filtration blotting of protein in the presence of sodium dodecyl sulfate (SDS) followed by a filtration-based immunoassay with a single anti-prion protein antibody, together with the improved fractionation procedure involving high concentrations of surfactant/detergent. The SDS/heat treatment renders unfolded PrP(Sc) quantitative retention on a polyvinylidene difluoride filter and allows enhancement of the analyte signal with immunodetection; thus, all of the tested specimens are determined with 100% accuracy. In addition, the immunoassay is completed in approximately 1h, indicating its usefulness not only for the screening of BSE specimens but probably also for the postmortem BSE diagnosis of fallen stock as the antibody recognizes the core part of PrP(Sc). The solid-phase immunoassay method, including the filtration blotting with SDS, would be applicable to determining even more sensitively proteins other than PrP(Sc), especially those having rigid conformations.
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Affiliation(s)
- Yoshiteru Kobayashi
- New Business and Technology Development Operations, Wako Pure Chemical Industries, Chuo-ku, Osaka 540-8605, Japan.
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119
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Everest SJ, Thorne L, Barnicle DA, Edwards JC, Elliott H, Jackman R, Hope J. Atypical prion protein in sheep brain collected during the British scrapie-surveillance programme. J Gen Virol 2006; 87:471-477. [PMID: 16432036 DOI: 10.1099/vir.0.81539-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Scrapie of sheep and goats is the most common prion disease (or transmissible spongiform encephalopathy, TSE) of mammals and aggregates of abnormal, proteinase-resistant prion protein (PrPSc) are found in all naturally occurring prion diseases. During active surveillance of British sheep for TSEs, 29 201 sheep brain stem samples were collected from abattoirs and analysed for the presence of PrPSc. Of these samples, 54 were found to be positive by using an ELISA screening test, but 28 of these could not be confirmed initially by immunohistochemistry. These unconfirmed or atypical cases were generally found in PrP genotypes normally associated with relative resistance to clinical scrapie and further biochemical analysis revealed that they contained forms of PrPSc with a relatively protease-sensitive amyloid core, some resembling those of Nor98 scrapie. The presence of these atypical forms of protease-resistant PrP raises concerns that some TSE disorders of PrP metabolism previously may have escaped identification in the British sheep population.
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Affiliation(s)
- S J Everest
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - L Thorne
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - D A Barnicle
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - J C Edwards
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - H Elliott
- Institute for Animal Health, Pirbright Laboratory, Woking, Surrey, UK
| | - R Jackman
- Department of TSE Molecular Biology, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - J Hope
- Veterinary Laboratories Agency Lasswade, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
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120
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Bolea R, Monleón E, Schiller I, Raeber AJ, Acín C, Monzón M, Martín-Burriel I, Struckmeyer T, Oesch B, Badiola JJ. Comparison of immunohistochemistry and two rapid tests for detection of abnormal prion protein in different brain regions of sheep with typical scrapie. J Vet Diagn Invest 2006; 17:467-9. [PMID: 16312240 DOI: 10.1177/104063870501700511] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
One of the "gold standard" techniques for postmortem confirmation of scrapie diagnosis in sheep and goats is immunohistochemical examination of brain tissue. Active surveillance for scrapie is mainly performed by rapid diagnostic tests on the basis of postmortem immunochemical detection of prion protein (PrP) in the obex tissue. The aim of this study was to determine the performance of 2 rapid tests, Prionics-Check LIA (a chemiluminescence sandwich enzyme-linked immunosorbent assay) and Prionics-Check Western blot for scrapie diagnosis when applied to brain areas other than the obex, in comparison with the recognized immunohistochemistry. Prion protein was detected in the obex, cervical spinal cord, and thalamus from all the scrapie-positive sheep by the 3 tests. Western blot and LIA were negative in other areas of the brain, although weak immunohistochemical staining was detected. The results show that the 2 rapid tests studied may detect PrP in brain areas other than the obex, although with a lower sensitivity than immunohistochemistry when there is minimal PrP deposition.
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Affiliation(s)
- Rosa Bolea
- National Reference Centre for TSE, Facultad de Veterinaria, Zaragoza, Spain
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121
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122
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Opinion of the Scientific Panel on biological hazards (BIOHAZ) on classification of atypical Transmissible Spongiform Encephalopathy (TSE) cases in Small Ruminants. EFSA J 2005. [DOI: 10.2903/j.efsa.2005.276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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123
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Sabuncu E, Paquet S, Chapuis J, Moudjou M, Lai TL, Grassi J, Baron U, Laude H, Vilette D. Prion proteins from susceptible and resistant sheep exhibit some distinct cell biological features. Biochem Biophys Res Commun 2005; 337:791-8. [PMID: 16214113 DOI: 10.1016/j.bbrc.2005.09.114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Accepted: 09/05/2005] [Indexed: 11/26/2022]
Abstract
It is well established that natural polymorphisms in the coding sequence of the PrP protein can control the expression of prion disease. Studies with a cell model of sheep prion infection have shown that ovine PrP allele associated with resistance to sheep scrapie may confer resistance by impairing the multiplication of the infectious agent. To further explore the biochemical and cellular mechanisms underlying the genetic control of scrapie susceptibility, we established permissive cells expressing two different PrP variants. In this study, we show that PrP variants with opposite effects on prion multiplication exhibit distinct cell biological features. These findings indicate that cell biological properties of ovine PrP can vary with natural polymorphisms and raise the possibility that differential interactions of PrP variants with the cellular machinery may contribute to permissiveness or resistance to prion multiplication.
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Affiliation(s)
- Elifsu Sabuncu
- Unité de Virologie et Immunologie Moléculaires, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France
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124
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Le Dur A, Béringue V, Andréoletti O, Reine F, Laï TL, Baron T, Bratberg B, Vilotte JL, Sarradin P, Benestad SL, Laude H. A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes. Proc Natl Acad Sci U S A 2005; 102:16031-6. [PMID: 16239348 PMCID: PMC1276041 DOI: 10.1073/pnas.0502296102] [Citation(s) in RCA: 205] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrP(c)), into a misfolded form, abnormal PrP (PrP(Sc)), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrP(Sc) detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrP(Sc) molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrP(ARR) allele (A(136)R(154)R(171)), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
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Affiliation(s)
- Annick Le Dur
- Virologie Immunologie Moléculaires and Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France
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125
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De Bosschere H, Roels S, Dechamps P, Vanopdenbosch E. TSE detected in a Belgian ARR-homozygous sheep via active surveillance. Vet J 2005; 173:449-51. [PMID: 16169265 DOI: 10.1016/j.tvjl.2005.07.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
It is commonly accepted that scrapie-resistance and -susceptibility in sheep are genetically controlled. Consequently, the selection of sheep with scrapie-resistant genotypes is currently one of the most important objectives of the sheep breeding associations. However, during the last two years, new data have become available on transmissible spongiform encephalopathy (TSE) cases in TSE-resistant sheep in several European Union member states. The present paper describes the first Belgian natural "atypical" TSE case in a sheep with a scrapie-resistant genotype (ARR/ARR) detected via active surveillance. No other infections or diseases were detected in the source flock. The continued finding of new "atypical" TSE cases in sheep with scrapie-resistant genotypes undermines the purpose and efficacy of the breeding programs.
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Affiliation(s)
- Hendrik De Bosschere
- Veterinary Agrochemical Research Centre, Department of Biocontrol, Groeselenberg 99, B-1180 Brussels (Ukkel), Belgium.
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126
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Scientific Report of the European Food Safety Authority on the Evaluation of Rapid post mortem TSE Tests intended for Small Ruminants. EFSA J 2005. [DOI: 10.2903/j.efsa.2005.49r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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127
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Monleón E, Monzón M, Hortells P, Bolea R, Acín C, Vargas F, Badiola JJ. Approaches to Scrapie diagnosis by applying immunohistochemistry and rapid tests on central nervous and lymphoreticular systems. J Virol Methods 2005; 125:165-71. [PMID: 15794986 DOI: 10.1016/j.jviromet.2005.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Revised: 12/16/2004] [Accepted: 01/08/2005] [Indexed: 10/25/2022]
Abstract
Comparative studies evaluating the performance of Transmissible Spongiform Encephalopathies (TSE) rapid tests (validated for Bovine Spongiform Encephalopathy samples) on Scrapie samples have not been reported widely, particularly those dealing with lymphoreticular system tissues to a much lesser extent. The main objective of this study was to compare the ability of two current rapid tests (Western blot and Luminiscence Immunoassay Prionics-Check; WB and LIA, respectively) to detect PrPsc using central nervous system as well as lymphoreticular system samples corresponding to naturally infected animals. Thirty-four Scrapie-affected sheep, 26 with clinical signs of the disease, were included in the study. Tonsil, retropharyngeal lymph node and medulla oblongata were assessed by three tests: immunohistochemistry (confirmatory test), WB and LIA (rapid tests). The conclusion which can be drawn from this study is the fact that all animals involved in the study, including those at a preclinical stage, could be diagnosed regardless of the test used (with immunohistochemistry consistently showing higher sensitivity) only when the analyses of both the central nervous system and the lymphoreticular system were considered. The choice of these tissues for routine diagnosis is, therefore, proposed as a valuable tool to highly reduce the number of undetected positive cases.
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Affiliation(s)
- E Monleón
- National Reference Centre for Transmissible Spongiform Encephalopathies, University of Zaragoza, Avda. Miguel Servet 177, 50013 Zaragoza, Spain
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128
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EFSA Scientific Report on the evaluation of rapid post mortem TSE tests intended for small ruminants. EFSA J 2005. [DOI: 10.2903/j.efsa.2005.31r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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129
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Gretzschel A, Buschmann A, Eiden M, Ziegler U, Lühken G, Erhardt G, Groschup MH. Strain typing of German transmissible spongiform encephalopathies field cases in small ruminants by biochemical methods. ACTA ACUST UNITED AC 2005; 52:55-63. [PMID: 15752263 DOI: 10.1111/j.1439-0450.2005.00827.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
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.
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Affiliation(s)
- A Gretzschel
- Friedrich-Loeffler-Institut (FLI), Institute for Novel and Emerging Diseases, Insel Riems, Germany
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130
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Moum T, Olsaker I, Hopp P, Moldal T, Valheim M, Moum T, Benestad SL. Polymorphisms at codons 141 and 154 in the ovine prion protein gene are associated with scrapie Nor98 cases. J Gen Virol 2005; 86:231-235. [PMID: 15604451 DOI: 10.1099/vir.0.80437-0] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Until June 2004, thirty-eight scrapie cases with unusual features, designated Nor98, have been diagnosed in Norway. This study investigated the distribution of PrP genotypes among Nor98 cases, their flock-mates and a random sample of Norwegian slaughtered sheep. The PrP genotype distribution of Nor98 cases differed markedly from that of previous cases of classical scrapie. A leucine/phenylalanine polymorphism at codon 141 with hitherto unknown significance to scrapie was strongly associated with Nor98 cases. Twenty of 38 (52.6 %) cases were either homozygous or heterozygous for phenylalanine at codon 141. In contrast, this allele was present in only 10.5 % of the flock-mates and 4.5 % of the random sample of slaughtered sheep. Moreover, the H(154) allele was represented in 24 of 38 (63.2 %) of Nor98 cases, as opposed to 27.0 % of Nor98 flock-mates and 17.0 % of the slaughtered sheep.
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Affiliation(s)
- Truls Moum
- Norwegian School of Veterinary Science, Department of Production Animal Clinical Sciences, Kyrkjevegen 332-334, N-4325 Sandnes, Norway
| | - Ingrid Olsaker
- Norwegian School of Veterinary Science, Department of Basic Sciences and Aquatic Medicine, PO Box 8146 Dep., N-0033 Oslo, Norway
| | - Petter Hopp
- National Veterinary Institute, PO Box 8156 Dep., N-0033 Oslo, Norway
| | - Torfinn Moldal
- National Veterinary Institute, PO Box 8156 Dep., N-0033 Oslo, Norway
| | - Mette Valheim
- National Veterinary Institute, PO Box 8156 Dep., N-0033 Oslo, Norway
| | - Torbjørn Moum
- University of Oslo, Department of Behavioural Sciences in Medicine, PO Box 1111, N-0317 Oslo, Norway
| | - Sylvie L Benestad
- National Veterinary Institute, PO Box 8156 Dep., N-0033 Oslo, Norway
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131
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132
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Madec JY, Simon S, Lezmi S, Bencsik A, Grassi J, Baron T. Abnormal prion protein in genetically resistant sheep from a scrapie-infected flock. J Gen Virol 2004; 85:3483-3486. [PMID: 15483266 DOI: 10.1099/vir.0.80220-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The central molecular event in transmissible spongiform encephalopathies, such as scrapie in sheep, is the accumulation in tissues of an abnormal isoform of the cellular prion protein. A previous investigation of 26 sheep showed that the accumulation of PrP(res) in brain correlated more with the prnp genotype than with the severity of the clinical disease. Here, the ability of a sandwich ELISA to detect PrP(res) distribution in the brain was demonstrated. Immunohistochemistry also strongly supported the hypothesis that the dorsal motor nucleus of the vagus nerve is the possible entry site in the brain for the scrapie agent. Remarkably, three asymptomatic (or possibly asymptomatic for scrapie) sheep carrying an allele known to be associated with clinical scrapie resistance (ARR), which were negative for the detection of PrP(res) by Western blotting and immunohistochemistry, were positive for the presence of PrP(res) by ELISA, raising the possibility of carriers resistant to the disease and possibly contributing to the persistence of scrapie in certain flocks.
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Affiliation(s)
- J-Y Madec
- AFSSA Lyon, 31 avenue Tony Garnier, 69364 Lyon cedex 07, France
| | - S Simon
- CEA, Service de Pharmacologie et d'Immunologie, CEA/Saclay, France
| | - S Lezmi
- AFSSA Lyon, 31 avenue Tony Garnier, 69364 Lyon cedex 07, France
| | - A Bencsik
- AFSSA Lyon, 31 avenue Tony Garnier, 69364 Lyon cedex 07, France
| | - J Grassi
- CEA, Service de Pharmacologie et d'Immunologie, CEA/Saclay, France
| | - T Baron
- AFSSA Lyon, 31 avenue Tony Garnier, 69364 Lyon cedex 07, France
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133
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Orge L, Galo A, Machado C, Lima C, Ochoa C, Silva J, Ramos M, Simas JP. Identification of putative atypical scrapie in sheep in Portugal. J Gen Virol 2004; 85:3487-3491. [PMID: 15483267 DOI: 10.1099/vir.0.80246-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Experimental transmission of bovine spongiform encephalopathy to sheep has prompted the implementation of a surveillance plan of scrapie in small ruminants by the European Union in all member states. Since its start over 30,000 animals have been tested, and the first seven cases of sheep with detectable PrP(res) deposition in the central nervous system have been identified in Portugal. Notably, the pattern of PrP(res) distribution in the brainstem was different from that previously described for scrapie and consistent in all seven animals. Moreover, the profile of the electrophoretic mobility of PrP(res) after proteinase K treatment was equivalent in all cases analysed but distinct from that observed for scrapie. Notably, four animals had genotypes rarely associated with scrapie, including one animal homozygous for A(136)R(154)R(171). There were no cases found to exhibit vacuolation, a pattern of PrP(res) distribution or PrP(res) electrophoretic mobility corresponding to scrapie. These data reveal a putative atypical scrapie strain in Portugal not linked to specific Prnp genotypes.
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Affiliation(s)
- Leonor Orge
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - Alexandre Galo
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - Carla Machado
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - Carla Lima
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - Cristina Ochoa
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - João Silva
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - Manuel Ramos
- Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal
| | - J Pedro Simas
- Laboratório de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal
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134
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Buschmann A, Lühken G, Schultz J, Erhardt G, Groschup MH. Neuronal accumulation of abnormal prion protein in sheep carrying a scrapie-resistant genotype (PrPARR/ARR). J Gen Virol 2004; 85:2727-2733. [PMID: 15302966 DOI: 10.1099/vir.0.79997-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
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 (PrPARR) 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.
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Affiliation(s)
- Anne Buschmann
- Federal Research Centre for Virus Diseases of Animals, Institute for Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald - Insel Riems, Germany
| | - Gesine Lühken
- Department of Animal Breeding and Genetics, Justus-Liebig-University Gießen, Ludwigstraße 21B, 35390 Gießen, Germany
| | - Julia Schultz
- Federal Research Centre for Virus Diseases of Animals, Institute for Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald - Insel Riems, Germany
| | - G Erhardt
- Department of Animal Breeding and Genetics, Justus-Liebig-University Gießen, Ludwigstraße 21B, 35390 Gießen, Germany
| | - Martin H Groschup
- Federal Research Centre for Virus Diseases of Animals, Institute for Novel and Emerging Infectious Diseases, Boddenblick 5a, 17493 Greifswald - Insel Riems, Germany
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135
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Budka H. Concern about Mad Cow Disease: End of the beginning, or beginning of the end? Wien Klin Wochenschr 2004; 116:505-7. [PMID: 15471175 DOI: 10.1007/bf03217701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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