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Kokemuller RD, Moore SJ, Bian J, West Greenlee MH, Greenlee JJ. Disease phenotype of classical sheep scrapie is changed upon experimental passage through white-tailed deer. PLoS Pathog 2023; 19:e1011815. [PMID: 38048370 PMCID: PMC10721168 DOI: 10.1371/journal.ppat.1011815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/14/2023] [Accepted: 11/09/2023] [Indexed: 12/06/2023] Open
Abstract
Prion agents occur in strains that are encoded by the structure of the misfolded prion protein (PrPSc). Prion strains can influence disease phenotype and the potential for interspecies transmission. Little is known about the potential transmission of prions between sheep and deer. Previously, the classical US scrapie isolate (No.13-7) had a 100% attack rate in white-tailed deer after oronasal challenge. The purpose of this study was to test the susceptibility of sheep to challenge with the scrapie agent after passage through white-tailed deer (WTD scrapie). Lambs of various prion protein genotypes were oronasally challenged with WTD scrapie. Sheep were euthanized and necropsied upon development of clinical signs or at the end of the experiment (72 months post-inoculation). Enzyme immunoassay, western blot, and immunohistochemistry demonstrated PrPSc in 4 of 10 sheep with the fastest incubation occurring in VRQ/VRQ sheep, which contrasts the original No.13-7 inoculum with a faster incubation in ARQ/ARQ sheep. Shorter incubation periods in VRQ/VRQ sheep than ARQ/ARQ sheep after passage through deer was suggestive of a phenotype change, so comparisons were made in ovinized mice and with sheep with known strains of classical sheep scrapie: No. 13-7 and x-124 (that has a more rapid incubation in VRQ/VRQ sheep). After mouse bioassay, the WTD scrapie and x-124 isolates have similar incubation periods and PrPSc conformational stability that are markedly different than the original No. 13-7 inoculum. Furthermore, brain tissues of sheep with WTD scrapie and x-124 scrapie have similar patterns of immunoreactivity that are distinct from sheep with No. 13-7 scrapie. Multiple lines of evidence suggest a phenotype switch when No. 13-7 scrapie prions are passaged through deer. This represents one example of interspecies transmission of prions resulting in the emergence or selection of new strain properties that could confound disease eradication and control efforts.
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Affiliation(s)
- Robyn D. Kokemuller
- Virus and Prion Research Unit, National Animal Disease Center, USDA, ARS, Ames, Iowa, United States of America
| | - S. Jo Moore
- Virus and Prion Research Unit, National Animal Disease Center, USDA, ARS, Ames, Iowa, United States of America
| | - Jifeng Bian
- Virus and Prion Research Unit, National Animal Disease Center, USDA, ARS, Ames, Iowa, United States of America
| | - M. Heather West Greenlee
- Department of Biomedical Sciences, Iowa State University College of Veterinary Medicine, Ames, Iowa, United States of America
| | - Justin J. Greenlee
- Virus and Prion Research Unit, National Animal Disease Center, USDA, ARS, Ames, Iowa, United States of America
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2
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Pirisinu L, Di Bari MA, D’Agostino C, Vanni I, Riccardi G, Marcon S, Vaccari G, Chiappini B, Benestad SL, Agrimi U, Nonno R. A single amino acid residue in bank vole prion protein drives permissiveness to Nor98/atypical scrapie and the emergence of multiple strain variants. PLoS Pathog 2022; 18:e1010646. [PMID: 35731839 PMCID: PMC9255773 DOI: 10.1371/journal.ppat.1010646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/05/2022] [Accepted: 06/03/2022] [Indexed: 12/03/2022] Open
Abstract
Prions are infectious agents that replicate through the autocatalytic misfolding of the cellular prion protein (PrPC) into infectious aggregates (PrPSc) causing fatal neurodegenerative diseases in humans and animals. Prions exist as strains, which are encoded by conformational variants of PrPSc. The transmissibility of prions depends on the PrPC sequence of the recipient host and on the incoming prion strain, so that some animal prion strains are more contagious than others or are transmissible to new species, including humans. Nor98/atypical scrapie (AS) is a prion disease of sheep and goats reported in several countries worldwide. At variance with classical scrapie (CS), AS is considered poorly contagious and is supposed to be spontaneous in origin. The zoonotic potential of AS, its strain variability and the relationships with the more contagious CS strains remain largely unknown. We characterized AS isolates from sheep and goats by transmission in ovinised transgenic mice (tg338) and in two genetic lines of bank voles, carrying either methionine (BvM) or isoleucine (BvI) at PrP residue 109. All AS isolates induced the same pathological phenotype in tg338 mice, thus proving that they encoded the same strain, irrespective of their geographical origin or source species. In bank voles, we found that the M109I polymorphism dictates the susceptibility to AS. BvI were susceptible and faithfully reproduced the AS strain, while the transmission in BvM was highly inefficient and was characterized by a conformational change towards a CS-like prion strain. Sub-passaging experiments revealed that the main strain component of AS is accompanied by minor CS-like strain components, which can be positively selected during replication in both AS-resistant or AS-susceptible animals. These findings add new clues for a better comprehension of strain selection dynamics in prion infections and have wider implications for understanding the origin of contagious prion strains, such as CS. Prions are transmissible agents responsible for fatal neurodegenerative diseases in humans and animals. Prions exist as strains, exhibiting distinct disease phenotypes and transmission properties. Some prion diseases occur sporadically with a supposedly spontaneous origin, while others are contagious and give rise to epidemics, mainly in animals. We investigated the strain properties of Nor98/atypical scrapie (AS), a sporadic prion disease of small ruminants. We found that AS was faithfully reproduced not only in a homologous context, i.e. ovinised transgenic mice, but also in an unrelated animal species, the bank vole. A natural polymorphism of the bank vole prion protein, coding for methionine (BvM) or for isoleucine (BvI) at codon 109, dictated the susceptibility of voles to AS, with BvI being highly susceptible to AS and BvM rather resistant. Most importantly, the M109I polymorphism mediated the emergence of AS-derived mutant prion strains resembling classical scrapie (CS), a contagious prion disease. Finally, by sub-passages in bank voles, we found that the main strain component of AS is accompanied by minor CS-like strain components, which can be positively selected during replication in both AS-resistant or AS-susceptible vole lines. These findings allow a better understanding of strain selection dynamics and suggest a link between sporadic and contagious prion diseases.
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Affiliation(s)
- Laura Pirisinu
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Michele Angelo Di Bari
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Claudia D’Agostino
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Ilaria Vanni
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Geraldina Riccardi
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Stefano Marcon
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Gabriele Vaccari
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Barbara Chiappini
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | | | - Umberto Agrimi
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Romolo Nonno
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
- * E-mail:
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3
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Favole A, Mazza M, D'Angelo A, Lombardi G, Palmitessa C, Dell'Atti L, Cagnotti G, Berrone E, Gallo M, Avanzato T, Messana E, Masoero L, Acutis PL, Meloni D, Cardone F, Caramelli M, Casalone C, Corona C. RT-QuIC detection of pathological prion protein in subclinical goats following experimental oral transmission of L-type BSE. BMC Res Notes 2021; 14:442. [PMID: 34876215 PMCID: PMC8650279 DOI: 10.1186/s13104-021-05859-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/23/2021] [Indexed: 11/20/2022] Open
Abstract
Objective The spread of bovine spongiform encephalopathy (BSE) agent to small ruminants is still a major issue in the surveillance of transmissible spongiform encephalopathies (TSEs). L-type bovine spongiform encephalopathy (L-BSE) is an atypical form of BSE with an unknown zoonotic potential that is transmissible to cattle and small ruminants. Our current knowledge of bovine atypical prion strains in sheep and goat relies only on experimental transmission studies by intracranial inoculation. To assess oral susceptibility of goats to L-BSE, we orally inoculated five goats with cattle L-BSE brain homogenates and investigated pathogenic prion protein (PrPsc) distribution by an ultrasensitive in vitro conversion assay known as Real-Time Quaking Induced Conversion (RT-QuIC). Results Despite a prolonged observation period of 80 months, all these animals and the uninfected controls did not develop clinical signs referable to TSEs and tested negative by standard diagnostics. Otherwise, RT-QuIC analysis showed seeding activity in five out of five examined brain samples. PrPsc accumulation was also detected in spinal cord and lymphoreticular system. These results indicate that caprine species are susceptible to L-BSE by oral transmission and that ultrasensitive prion tests deserve consideration to improve the potential of current surveillance systems against otherwise undetectable forms of animal prion infections.
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Affiliation(s)
- Alessandra Favole
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy.
| | - Maria Mazza
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | | | - Guerino Lombardi
- Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia-Romagna, Brescia, Italy
| | - Claudia Palmitessa
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Luana Dell'Atti
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | | | - Elena Berrone
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Marina Gallo
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Tiziana Avanzato
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Erika Messana
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Loretta Masoero
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Pier Luigi Acutis
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Daniela Meloni
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | | | - Maria Caramelli
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Cristina Casalone
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy
| | - Cristiano Corona
- S.C. Neuroscienze, Lab. di Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154, Turin, Italy.
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Arnold M, Ru G, Simmons M, Vidal‐Diez A, Ortiz‐Pelaez A, Stella P. Scientific report on the analysis of the 2-year compulsory intensified monitoring of atypical scrapie. EFSA J 2021; 19:e06686. [PMID: 34262626 PMCID: PMC8265166 DOI: 10.2903/j.efsa.2021.6686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The European Commission asked EFSA whether the scientific data on the 2-year intensified monitoring in atypical scrapie (AS) outbreaks (2013-2020) provide any evidence on the contagiousness of AS, and whether they added any new knowledge on the epidemiology of AS. An ad hoc data set from intensified monitoring in 22 countries with index case/s of AS in sheep and/or goats (742 flocks from 20 countries, 76 herds from 11 countries) was analysed. No secondary cases were confirmed in goat herds, while 35 secondary cases were confirmed in 28 sheep flocks from eight countries. The results of the calculated design prevalence and of a model simulation indicated that the intensified monitoring had limited ability to detect AS, with no difference between countries with or without secondary cases. A regression model showed an increased, but not statistically significant, prevalence (adjusted by surveillance stream) of secondary cases in infected flocks compared with that of index cases in the non-infected flocks (general population). A simulation model of within-flock transmission, comparing a contagious (i.e. transmissible between animals under natural conditions) with a non-contagious scenario, produced a better fit of the observed data with the non-contagious scenario, in which each sheep in a flock had the same probability of developing AS in the first year of life. Based on the analyses performed, and considering uncertainties and data limitations, it was concluded that there is no new evidence that AS can be transmitted between animals under natural conditions, and it is considered more likely (subjective probability range 50-66%) that AS is a non-contagious, rather than a contagious disease. The analysis of the data of the EU intensified monitoring in atypical scrapie infected flocks/herds confirmed some of the known epidemiological features of AS but identified that major knowledge gaps still remain.
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5
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Bartz JC. Environmental and host factors that contribute to prion strain evolution. Acta Neuropathol 2021; 142:5-16. [PMID: 33899132 PMCID: PMC8932343 DOI: 10.1007/s00401-021-02310-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 02/08/2023]
Abstract
Prions are novel pathogens that are composed entirely of PrPSc, the self-templating conformation of the host prion protein, PrPC. Prion strains are operationally defined as a heritable phenotype of disease that are encoded by strain-specific conformations of PrPSc. The factors that influence the relative distribution of strains in a population are only beginning to be understood. For prions with an infectious etiology, environmental factors, such as strain-specific binding to surfaces and resistance to weathering, can influence which strains are available for transmission to a naïve host. Strain-specific differences in efficiency of infection by natural routes of infection can also select for prion strains. The host amino acid sequence of PrPC has the greatest effect on dictating the repertoire of prion strains. The relative abundance of PrPC, post-translational modifications of PrPC and cellular co-factors involved in prion conversion can also provide conditions that favor the prevalence of a subset of prion strains. Additionally, prion strains can interfere with each other, influencing the emergence of a dominant strain. Overall, both environmental and host factors may influence the repertoire and distribution of strains within a population.
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Affiliation(s)
- Jason C Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, 2500 California Plaza, Omaha, NE, 68178, USA.
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6
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BSE can propagate in sheep co-infected or pre-infected with scrapie. Sci Rep 2021; 11:11931. [PMID: 34099797 PMCID: PMC8184847 DOI: 10.1038/s41598-021-91397-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/24/2021] [Indexed: 11/29/2022] Open
Abstract
To understand the possible role of mixed-prion infections in disease presentation, the current study reports the co-infection of sheep with bovine spongiform encephalopathy (BSE) and scrapie. The bovine BSE agent was inoculated subcutaneously into sheep with ARQ/ARQ or VRQ/ARQ PRNP genotypes either at the same time as subcutaneous challenge with scrapie, or three months later. In addition, VRQ/VRQ sheep naturally infected with scrapie after being born into a scrapie-affected flock were challenged subcutaneously with BSE at eight or twenty one months-of-age. Sheep were analysed by incubation period/attack rate, and western blot of brain tissue determined the presence of BSE or scrapie-like PrPSc. Serial protein misfolding cyclic amplification (sPMCA) that can detect very low levels of BSE in the presence of an excess of scrapie agent was also applied to brain and lymphoreticular tissue. For VRQ/ARQ sheep challenged with mixed infections, scrapie-like incubation periods were produced, and no BSE agent was detected. However, whilst ARQ/ARQ sheep developed disease with BSE-like incubation periods, some animals had a dominant scrapie western blot phenotype in brain, but BSE was detected in these sheep by sPMCA. In addition, VRQ/VRQ animals challenged with BSE after natural exposure to scrapie had scrapie-like incubation periods and dominant scrapie PrPSc in brain, but one sheep had BSE detectable by sPMCA in the brain. Overall, the study demonstrates for the first time that for scrapie/BSE mixed infections, VRQ/ARQ sheep with experimental scrapie did not propagate BSE but VRQ/VRQ sheep with natural scrapie could propagate low levels of BSE, and whilst BSE readily propagated in ARQ/ARQ sheep it was not always the dominant PrPSc strain in brain tissue. Indeed, for several animals, a dominant scrapie biochemical phenotype in brain did not preclude the presence of BSE prion.
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7
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Abstract
Sporadic Creutzfeldt-Jakob disease (sCJD) cases are currently classified according to the methionine/valine polymorphism at codon 129 of the PRNP gene and the proteinase K-digested abnormal prion protein (PrPres) isoform identified by Western blotting (type 1 or type 2). Converging evidence led to the view that MM/MV1, VV/MV2, and VV1 and MM2 sCJD cases are caused by distinct prion strains. However, in a significant proportion of sCJD patients, both type 1 and type 2 PrPres were reported to accumulate in the brain, which raised questions about the diversity of sCJD prion strains and the coexistence of two prion strains in the same patient. In this study, a panel of sCJD brain isolates (n = 29) that displayed either a single or mixed type 1/type 2 PrPres were transmitted into human-PrP-expressing mice (tgHu). These bioassays demonstrated that two distinct prion strains (M1CJD and V2CJD) were associated with the development of sCJD in MM1/MV1 and VV2/MV2 patients. However, in about 35% of the investigated VV and MV cases, transmission results were consistent with the presence of both M1CJD and V2CJD strains, including in patients who displayed a "pure" type 1 or type 2 PrPres The use of a highly sensitive prion in vitro amplification technique that specifically probes the V2CJD strain revealed the presence of the V2CJD prion in more than 80% of the investigated isolates, including isolates that propagated as a pure M1CJD strain in tgHu. These results demonstrate that at least two sCJD prion strains can be present in a single patient.IMPORTANCE sCJD occurrence is currently assumed to result from spontaneous and stochastic formation of a misfolded PrP nucleus in the brains of affected patients. This original nucleus then recruits and converts nascent PrPC into PrPSc, leading to the propagation of prions in the patient's brain. Our study demonstrates the coexistence of two prion strains in the brains of a majority of the 23 sCJD patients investigated. The relative proportion of these sCJD strains varied both between patients and between brain areas in a single patient. These findings strongly support the view that the replication of an sCJD prion strain in the brain of a patient can result in the propagation of different prion strain subpopulations. Beyond its conceptual importance for our understanding of prion strain properties and evolution, the sCJD strain mixture phenomenon and its frequency among patients have important implications for the development of therapeutic strategies for prion diseases.
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8
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Zetterberg H, Bozzetta E, Favole A, Corona C, Cavarretta MC, Ingravalle F, Blennow K, Pocchiari M, Meloni D. Neurofilaments in blood is a new promising preclinical biomarker for the screening of natural scrapie in sheep. PLoS One 2019; 14:e0226697. [PMID: 31856243 PMCID: PMC6922435 DOI: 10.1371/journal.pone.0226697] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/02/2019] [Indexed: 12/14/2022] Open
Abstract
Scrapie is a fatal neurodegenerative disease of sheep and goats belonging to the group of Transmissible Spongiform Encephalopathy or prion diseases. The EU has adopted mandatory measures for scrapie surveillance to safeguard public and animal health because it is highly contagious and might decimate all genetic susceptible animals in affected flocks. Definite diagnosis of scrapie relies on the detection of the pathological prion protein in brain tissues and there are still no blood biomarkers available for making diagnosis in living animals that can be used for the screening of sheep in scrapie-affected flocks. Neurofilament light (NfL) protein, a valid biomarker for neuronal and axonal damages, can now be easily measured in blood by the ultra-sensitive single molecule array (Simoa) technology. Recent work reported that serum NfL is increased in neurodegenerative diseases, including human prion diseases, but no data are available for scrapie or other animal prion diseases. Here, we found that the median serum NfL concentration in scrapie animals (56.2, IQR 42.2–84.8, n = 9) was more than 15 times higher (p = 0.00084) than that found in control samples (3.4, IQR 3.0–26.3, n = 11). Moreover, serum NfL concentration in scrapie sheep with clinical signs (n = 2; 75.3, 15.7 pg/ml) did not significantly (p = 0.541; t-test) differ from scrapie animals without clinical signs (n = 7; 61.0, 10.7 pg/ml). The receiver operating characteristic (ROC) curve analysis estimated the cut-off value of 31 pg/ml serum NfL for distinguishing scrapie-infected sheep from controls. The application of this cut-off value gives an accuracy of the test of 95% (percent error of 5.23%). These data indicate that the Simoa test for serum NfL might be a useful screening method for detecting preclinical scrapie in living sheep. Finally, the preliminary data reported here need confirmation in large and more structured studies.
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Affiliation(s)
- Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, United Kingdom
- UK Dementia Research Institute at UCL, University College London, London, United Kingdom
| | - Elena Bozzetta
- Istituto zooprofilattico del Piemonte Liguria e Valle d’Aosta, Turin, Italy
| | - Alessandra Favole
- Istituto zooprofilattico del Piemonte Liguria e Valle d’Aosta, Turin, Italy
| | - Cristiano Corona
- Istituto zooprofilattico del Piemonte Liguria e Valle d’Aosta, Turin, Italy
| | | | | | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
| | | | - Daniela Meloni
- Istituto zooprofilattico del Piemonte Liguria e Valle d’Aosta, Turin, Italy
- * E-mail:
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9
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Langeveld JPM, Pirisinu L, Jacobs JG, Mazza M, Lantier I, Simon S, Andréoletti O, Acin C, Esposito E, Fast C, Groschup M, Goldmann W, Spiropoulos J, Sklaviadis T, Lantier F, Ekateriniadou L, Papasavva-Stylianou P, van Keulen LJM, Acutis PL, Agrimi U, Bossers A, Nonno R. Four types of scrapie in goats differentiated from each other and bovine spongiform encephalopathy by biochemical methods. Vet Res 2019; 50:97. [PMID: 31767033 PMCID: PMC6878695 DOI: 10.1186/s13567-019-0718-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/16/2019] [Indexed: 01/03/2023] Open
Abstract
Scrapie in goats has been known since 1942, the archetype of prion diseases in which only prion protein (PrP) in misfolded state (PrPSc) acts as infectious agent with fatal consequence. Emergence of bovine spongiform encephalopathy (BSE) with its zoonotic behaviour and detection in goats enhanced fears that its source was located in small ruminants. However, in goats knowledge on prion strain typing is limited. A European-wide study is presented concerning the biochemical phenotypes of the protease resistant fraction of PrPSc (PrPres) in over thirty brain isolates from transmissible spongiform encephalopathy (TSE) affected goats collected in seven countries. Three different scrapie forms were found: classical scrapie (CS), Nor98/atypical scrapie and one case of CH1641 scrapie. In addition, CS was found in two variants-CS-1 and CS-2 (mainly Italy)-which differed in proteolytic resistance of the PrPres N-terminus. Suitable PrPres markers for discriminating CH1641 from BSE (C-type) appeared to be glycoprofile pattern, presence of two triplets instead of one, and structural (in)stability of its core amino acid region. None of the samples exhibited BSE like features. BSE and these four scrapie types, of which CS-2 is new, can be recognized in goats with combinations of a set of nine biochemical parameters.
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Affiliation(s)
- Jan P M Langeveld
- Wageningen BioVeterinary Research (WBVR), Wageningen University & Research, Houtribweg 39, 8221RA, Lelystad, The Netherlands.
| | - Laura Pirisinu
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanita (ISS), 299-00161, Rome, Italy
| | - Jorg G Jacobs
- Wageningen BioVeterinary Research (WBVR), Wageningen University & Research, Houtribweg 39, 8221RA, Lelystad, The Netherlands
| | - Maria Mazza
- Italian Reference Centre for TSEs, Istituto Zooprofilattico Sperimentale del Piemonte (IZSTO), 10154, Turin, TO, Italy
| | - Isabelle Lantier
- UMR 1282 ISP, Institut National de la Recherche Agronomique (INRA), University of Tours, 37380, Nouzilly, France
| | - Stéphanie Simon
- Commissariat à l'Énergie Atomique (CEA), 91191, Gif-sur-Yvette, France
| | - Olivier Andréoletti
- UMR INRA/ENVT 1225 IHAP, École Nationale Vétérinaire de Toulouse (ENVT), 31300, Toulouse, France
| | - Cristina Acin
- Research Centre for TSE and Emerging Transmissible Diseases, University of Zaragoza (UNIZAR), 50013, Zaragoza, Spain
| | - Elena Esposito
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanita (ISS), 299-00161, Rome, Italy
| | - Christine Fast
- Friedrich-Loeffler-Institut (FLI), Institute of Novel and Emerging Infectious Diseases, Greifswald-Isle of Riems, 17493, Greifswald, Germany
| | - Martin Groschup
- Friedrich-Loeffler-Institut (FLI), Institute of Novel and Emerging Infectious Diseases, Greifswald-Isle of Riems, 17493, Greifswald, Germany
| | - Wilfred Goldmann
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh (UEDIN), Easter Bush, Midlothian, EH25 9RG, UK
| | - John Spiropoulos
- Department of Pathology, Animal and Plant Health Agency (APHA), Woodham Lane, Addlestone, Surrey, KT15 3NB, UK
| | - Theodoros Sklaviadis
- School of Pharmacy, Aristotle University of Thessaloniki (AUTh), 54124, Thessaloniki, Greece
| | - Frederic Lantier
- UMR 1282 ISP, Institut National de la Recherche Agronomique (INRA), University of Tours, 37380, Nouzilly, France
| | - Loukia Ekateriniadou
- Hellenic Agricultural Organization DEMETER, Veterinary Research Institute, 57001, Thessaloniki, Greece
| | | | - Lucien J M van Keulen
- Wageningen BioVeterinary Research (WBVR), Wageningen University & Research, Houtribweg 39, 8221RA, Lelystad, The Netherlands
| | - Pier-Luigi Acutis
- Italian Reference Centre for TSEs, Istituto Zooprofilattico Sperimentale del Piemonte (IZSTO), 10154, Turin, TO, Italy
| | - Umberto Agrimi
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanita (ISS), 299-00161, Rome, Italy
| | - Alex Bossers
- Wageningen BioVeterinary Research (WBVR), Wageningen University & Research, Houtribweg 39, 8221RA, Lelystad, The Netherlands
| | - Romolo Nonno
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanita (ISS), 299-00161, Rome, Italy
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10
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Koutsoumanis K, Allende A, Alvarez-Ordoňez A, Bolton D, Bover-Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Skandamis P, Suffredini E, Andreoletti O, Benestad SL, Comoy E, Nonno R, da Silva Felicio T, Ortiz-Pelaez A, Simmons MM. Update on chronic wasting disease (CWD) III. EFSA J 2019; 17:e05863. [PMID: 32626163 PMCID: PMC7008890 DOI: 10.2903/j.efsa.2019.5863] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The European Commission asked EFSA for a Scientific Opinion: to revise the state of knowledge about the differences between the chronic wasting disease (CWD) strains found in North America (NA) and Europe and within Europe; to review new scientific evidence on the zoonotic potential of CWD and to provide recommendations to address the potential risks and to identify risk factors for the spread of CWD in the European Union. Full characterisation of European isolates is being pursued, whereas most NA CWD isolates have not been characterised in this way. The differing surveillance programmes in these continents result in biases in the types of cases that can be detected. Preliminary data support the contention that the CWD strains identified in Europe and NA are different and suggest the presence of strain diversity in European cervids. Current data do not allow any conclusion on the implications of strain diversity on transmissibility, pathogenesis or prevalence. Available data do not allow any conclusion on the zoonotic potential of NA or European CWD isolates. The risk of CWD to humans through consumption of meat cannot be directly assessed. At individual level, consumers of meat, meat products and offal derived from CWD-infected cervids will be exposed to the CWD agent(s). Measures to reduce human dietary exposure could be applied, but exclusion from the food chain of whole carcasses of infected animals would be required to eliminate exposure. Based on NA experiences, all the risk factors identified for the spread of CWD may be associated with animals accumulating infectivity in both the peripheral tissues and the central nervous system. A subset of risk factors is relevant for infected animals without involvement of peripheral tissues. All the risk factors should be taken into account due to the potential co-localisation of animals presenting with different disease phenotypes.
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11
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Babelhadj B, Di Bari MA, Pirisinu L, Chiappini B, Gaouar SBS, Riccardi G, Marcon S, Agrimi U, Nonno R, Vaccari G. Prion Disease in Dromedary Camels, Algeria. Emerg Infect Dis 2018; 24:1029-1036. [PMID: 29652245 PMCID: PMC6004840 DOI: 10.3201/eid2406.172007] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Prions cause fatal and transmissible neurodegenerative diseases, including
Creutzfeldt-Jakob disease in humans, scrapie in small ruminants, and bovine
spongiform encephalopathy (BSE). After the BSE epidemic, and the associated
human infections, began in 1996 in the United Kingdom, general concerns have
been raised about animal prions. We detected a prion disease in dromedary camels
(Camelus dromedarius) in Algeria. Symptoms suggesting prion
disease occurred in 3.1% of dromedaries brought for slaughter to the Ouargla
abattoir in 2015–2016. We confirmed diagnosis by detecting pathognomonic
neurodegeneration and disease-specific prion protein (PrPSc) in brain
tissues from 3 symptomatic animals. Prion detection in lymphoid tissues is
suggestive of the infectious nature of the disease. PrPSc biochemical
characterization showed differences with BSE and scrapie. Our identification of
this prion disease in a geographically widespread livestock species requires
urgent enforcement of surveillance and assessment of the potential risks to
human and animal health.
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12
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Mathiason CK. Scrapie, CWD, and Transmissible Mink Encephalopathy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 150:267-292. [PMID: 28838664 DOI: 10.1016/bs.pmbts.2017.07.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Transmissible spongiform encephalopathies (TSEs), or prions, are neurodegenerative diseases that affect a variety of animal species, including humans. Cruetzfeldt-Jakob disease (CJD) in humans, sheep and goat scrapie, chronic wasting disease (CWD) of cervids, and transmissible mink encephalopathy (TME) of mink are classified as TSEs. According to the "protein-only" hypothesis (Prusiner, 1982),1 prions are devoid of nucleic acids and consist of assemblies of misfolded host-encoded normal protein, the prion protein (PrPC). Prion propagation is thought to occur by a templating mechanism during which PrPC is recruited, converted to a disease-associated isoform (PrPD), and assembled onto the growing amyloid fibril. This fibular assembly is infectious, with ability to initiate disease processes similar to other pathogenic agents. Evidence indicates that scrapie, CWD, and TME disease processes follow this rule.
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13
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Meloni D, Bozzetta E, Langeveld JPM, Groschup MH, Goldmann W, Andrèoletti O, Lantier I, Van Keulen L, Bossers A, Pitardi D, Nonno R, Sklaviadis T, Ingravalle F, Peletto S, Colussi S, Acutis PL. EU-approved rapid tests might underestimate bovine spongiform encephalopathy infection in goats. J Vet Diagn Invest 2017; 29:232-236. [PMID: 28068881 DOI: 10.1177/1040638716688045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We report the diagnostic sensitivity of 3 EU-approved rapid tests (ELISAs; 1 from IDEXX and 2 from Bio-Rad) for the detection of transmissible spongiform encephalopathy diseases in goats. Ninety-eight goat brainstem samples were tested. All the rapid tests had 100% specificity and ≥80% sensitivity, with the IDEXX test significantly more sensitive than the 2 Bio-Rad tests. All tests detected 100% of samples from goats with clinical scrapie, but missed 8% (IDEXX) to 33% (Bio-Rad SG) of samples from preclinical goats. Importantly, only IDEXX picked up all samples from clinical bovine spongiform encephalopathy (BSE)-infected goats, whereas the other 2 rapid tests missed 15% (Bio-Rad SG) to 25% (Bio-Rad SAP). These results show that a fraction of preclinical scrapie infections are likely missed by EU surveillance, with sensitivity of detection strongly dependent on the choice of the rapid test. Moreover, a significant proportion of clinical BSE infections are underestimated by using either Bio-Rad test. Assuming that the same sensitivity on preclinical goats would also occur in BSE-infected goats, our data suggest that IDEXX is likely the most sensitive test for detecting preclinical field cases of BSE infection in goats, although with an 8% failure rate. These results raise some concerns about the reliability of current EU surveillance figures on BSE infection in goats.
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Affiliation(s)
- Daniela Meloni
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Elena Bozzetta
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Jan P M Langeveld
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Martin H Groschup
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Wilfred Goldmann
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Olivier Andrèoletti
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Isabelle Lantier
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Lucien Van Keulen
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Alex Bossers
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Danilo Pitardi
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Romolo Nonno
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Theodoros Sklaviadis
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Francesco Ingravalle
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Simone Peletto
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Silvia Colussi
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
| | - Pier Luigi Acutis
- CEA, Centro di Referenza Nazionale per lo Studio e le Ricerche sulle Encefalopatie Animali e Neuropatologie Comparate, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy (Meloni, Bozzetta, Pitardi, Ingravalle, Peletto, Colussi, Acutis).,Central Veterinary Institute part of Wageningen UR, Lelystad, the Netherlands (Langeveld, Van Keulen, Bossers).,Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Insel Riems, Germany (Groschup).,Roslin Institute and R(D)SVS University of Edinburgh, Roslin, Midlothian, United Kingdom (Goldmann).,UMR INRA ENVT 1225 Interactions Hotes Agents Pathògenes, ENVT, Toulouse, France (Andrèoletti).,ISP, INRA, Université Tours, Nouzilly, France (Lantier).,Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità (ISS), Rome, Italy (Nonno).,Aristotle University, Laboratory of Pharmacology, Department of Pharmaceutical Sciences, School of Health Sciences Thessaloniki, Greece (Sklaviadis)
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14
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Abstract
Prion diseases affect a wide range of mammal species and are caused by a misfolded self-propagating isoform (PrPSc) of the normal prion protein (PrPC). Distinct strains of prions exist and are operationally defined by differences in a heritable phenotype under controlled experimental transmission conditions. Prion strains can differ in incubation period, clinical signs of disease, tissue tropism, and host range. The mechanism by which a protein-only pathogen can encode strain diversity is only beginning to be understood. The prevailing hypothesis is that prion strain diversity is encoded by strain-specific conformations of PrPSc; however, strain-specific cellular cofactors have been identified in vitro that may also contribute to prion strain diversity. Although much progress has been made on understanding the etiological agent of prion disease, the relationship between the strain-specific properties of PrPSc and the resulting phenotype of disease in animals is poorly understood.
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Affiliation(s)
- Jason C Bartz
- Department of Medical Microbiology and Immunology, School of Medicine, Creighton University, Omaha, Nebraska 68178
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15
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Epidemiological investigations on the potential transmissibility of a rare disease: the case of atypical scrapie in Great Britain. Epidemiol Infect 2016; 144:2107-16. [PMID: 26976340 DOI: 10.1017/s0950268816000303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Multiple cases of atypical scrapie in the same holding and co-existence with classical scrapie have been reported in Great Britain. A two-stage simulation tool was developed by combining a sampling algorithm and a hierarchical Bayesian model to simulate the number of positive cases of atypical scrapie from: (i) random sampling and (ii) using the actual sampled population in Great Britain, being the output probability of detection of flocks with one and more cases. Cluster analysis was conducted to assess the level of geographical over- and under-sampling over the years. The probability of detecting at least two cases of atypical scrapie in the same holding is much lower in simulated random data than in simulated actual data for all scenarios. Sampling bias in the selection of sheep for testing led to multiple sampling from fewer but larger holdings, Scotland, and areas of Wales were under-sampled and the South-West and East of England oversampled. The pattern of atypical scrapie cases observed is unlikely to be explained by a multi-case event epidemiologically linked. The co-existence of classical and atypical scrapie is a rare event with 19 holdings detected in GB and does not suggest an epidemiological link between the two types of disease.
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PrP genotype frequencies and risk evaluation for scrapie in dairy sheep breeds from southern Italy. Prev Vet Med 2015; 122:318-24. [DOI: 10.1016/j.prevetmed.2015.10.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 09/30/2015] [Accepted: 10/28/2015] [Indexed: 11/23/2022]
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Berrone E, Corona C, Mazza M, Costassa EV, Faro ML, Properzi F, Guglielmetti C, Maurella C, Caramelli M, Deregibus MC, Camussi G, Casalone C. Detection of cellular prion protein in exosomes derived from ovine plasma. J Gen Virol 2015; 96:3698-3702. [PMID: 26399471 PMCID: PMC4804764 DOI: 10.1099/jgv.0.000291] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 09/18/2015] [Indexed: 01/01/2023] Open
Abstract
Prion protein (PrP) is present at extremely low levels in the blood of animals and its detection is complicated by the poor sensitivity of current standard methodologies. Interesting results have been obtained with recent advanced technologies that are able to detect minute amounts of the pathological PrP (PrPSc), but their efficiency is reduced by various factors present in blood. In this study, we were able to extract cellular PrP (PrPC) from plasma-derived exosomes by a simple, fast method without the use of differential ultracentrifugation and to visualize it by Western blotting, reducing the presence of most plasma proteins. This result confirms that blood is capable of releasing PrP in association with exosomes and could be useful to better study its role in the pathogenesis of transmissible spongiform encephalopathies.
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Affiliation(s)
- Elena Berrone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Cristiano Corona
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Maria Mazza
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Elena Vallino Costassa
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Monica Lo Faro
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Francesca Properzi
- Department of Cellular Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Chiara Guglielmetti
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Cristiana Maurella
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Maria Caramelli
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
| | - Maria Chiara Deregibus
- Department of Internal Medicine and Molecular Biotechnology Center, University of Turin, Corso Dogliotti 14, 10126 Turin, Italy
| | - Giovanni Camussi
- Department of Internal Medicine and Molecular Biotechnology Center, University of Turin, Corso Dogliotti 14, 10126 Turin, Italy
| | - Cristina Casalone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Turin, Italy
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Methods for Differentiating Prion Types in Food-Producing Animals. BIOLOGY 2015; 4:785-813. [PMID: 26580664 PMCID: PMC4690018 DOI: 10.3390/biology4040785] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/29/2015] [Accepted: 11/04/2015] [Indexed: 12/05/2022]
Abstract
Prions are an enigma amongst infectious disease agents as they lack a genome yet confer specific pathologies thought to be dictated mainly, if not solely, by the conformation of the disease form of the prion protein (PrPSc). Prion diseases affect humans and animals, the latter including the food-producing ruminant species cattle, sheep, goats and deer. Importantly, it has been shown that the disease agent of bovine spongiform encephalopathy (BSE) is zoonotic, causing variant Creutzfeldt Jakob disease (vCJD) in humans. Current diagnostic tests can distinguish different prion types and in food-producing animals these focus on the differentiation of BSE from the non-zoonotic agents. Whilst BSE cases are now rare, atypical forms of both scrapie and BSE have been reported, as well as two types of chronic wasting disease (CWD) in cervids. Typing of animal prion isolates remains an important aspect of prion diagnosis and is now becoming more focused on identifying the range of prion types that are present in food-producing animals and also developing tests that can screen for emerging, novel prion diseases. Here, we review prion typing methodologies in light of current and emerging prion types in food-producing animals.
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Deer Prion Proteins Modulate the Emergence and Adaptation of Chronic Wasting Disease Strains. J Virol 2015; 89:12362-73. [PMID: 26423950 PMCID: PMC4665243 DOI: 10.1128/jvi.02010-15] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/23/2015] [Indexed: 12/02/2022] Open
Abstract
Transmission of chronic wasting disease (CWD) between cervids is influenced by the primary structure of the host cellular prion protein (PrPC). In white-tailed deer, PRNP alleles encode the polymorphisms Q95 G96 (wild type [wt]), Q95 S96 (referred to as the S96 allele), and H95 G96 (referred to as the H95 allele), which differentially impact CWD progression. We hypothesize that the transmission of CWD prions between deer expressing different allotypes of PrPC modifies the contagious agent affecting disease spread. To evaluate the transmission properties of CWD prions derived experimentally from deer of four PRNP genotypes (wt/wt, S96/wt, H95/wt, or H95/S96), transgenic (tg) mice expressing the wt allele (tg33) or S96 allele (tg60) were challenged with these prion agents. Passage of deer CWD prions into tg33 mice resulted in 100% attack rates, with the CWD H95/S96 prions having significantly longer incubation periods. The disease signs and neuropathological and protease-resistant prion protein (PrP-res) profiles in infected tg33 mice were similar between groups, indicating that a prion strain (Wisc-1) common to all CWD inocula was amplified. In contrast, tg60 mice developed prion disease only when inoculated with the H95/wt and H95/S96 CWD allotypes. Serial passage in tg60 mice resulted in adaptation of a novel CWD strain (H95+) with distinct biological properties. Transmission of first-passage tg60CWD-H95+ isolates into tg33 mice, however, elicited two prion disease presentations consistent with a mixture of strains associated with different PrP-res glycotypes. Our data indicate that H95-PRNP heterozygous deer accumulated two CWD strains whose emergence was dictated by the PrPC primary structure of the recipient host. These findings suggest that CWD transmission between cervids expressing distinct PrPC molecules results in the generation of novel CWD strains.
IMPORTANCE CWD prions are contagious among wild and captive cervids in North America and in South Korea. We present data linking the amino acid variant Q95H in white-tailed deer cellular prion protein (PrPC) to the emergence of a novel CWD strain (H95+). We show that, upon infection, deer expressing H95-PrPC molecules accumulated a mixture of CWD strains that selectively propagated depending on the PRNP genotype of the host in which they were passaged. Our study also demonstrates that mice expressing the deer S96-PRNP allele, previously shown to be resistant to various cervid prions, are susceptible to H95+ CWD prions. The potential for the generation of novel strains raises the possibility of an expanded host range for CWD.
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Chong A, Kennedy I, Goldmann W, Green A, González L, Jeffrey M, Hunter N. Archival search for historical atypical scrapie in sheep reveals evidence for mixed infections. J Gen Virol 2015; 96:3165-3178. [PMID: 26281831 DOI: 10.1099/jgv.0.000234] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Natural scrapie in sheep occurs in classical and atypical forms, which may be distinguished on the basis of the associated neuropathology and properties of the disease-associated prion protein on Western blots. First detected in 1998, atypical scrapie is known to have occurred in UK sheep since the 1980s. However, its aetiology remains unclear and it is often considered as a sporadic, non-contagious disease unlike classical scrapie which is naturally transmissible. Although atypical scrapie tends to occur in sheep of prion protein (PRNP) genotypes that are different from those found predominantly in classical scrapie, there is some overlap so that there are genotypes in which both scrapie forms can occur. In this search for early atypical scrapie cases, we made use of an archive of fixed and frozen sheep samples, from both scrapie-affected and healthy animals (∼1850 individuals), dating back to the 1960s. Using a selection process based primarily on PRNP genotyping, but also on contemporaneous records of unusual clinical signs or pathology, candidate sheep samples were screened by Western blot, immunohistochemistry and strain-typing methods using tg338 mice. We identified, from early time points in the archive, three atypical scrapie cases, including one sheep which died in 1972 and two which showed evidence of mixed infection with classical scrapie. Cases with both forms of scrapie in the same animal as recognizable entities suggest that mixed infections have been around for a long time and may potentially contribute to the variety of scrapie strains.
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Affiliation(s)
- Angela Chong
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Iain Kennedy
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Wilfred Goldmann
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Andrew Green
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Lorenzo González
- Animal and Plant Health Agency (APHA - Lasswade), Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Martin Jeffrey
- Animal and Plant Health Agency (APHA - Lasswade), Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK
| | - Nora Hunter
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
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Does the Presence of Scrapie Affect the Ability of Current Statutory Discriminatory Tests To Detect the Presence of Bovine Spongiform Encephalopathy? J Clin Microbiol 2015; 53:2593-604. [PMID: 26041899 DOI: 10.1128/jcm.00508-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/27/2015] [Indexed: 11/20/2022] Open
Abstract
Current European Commission (EC) surveillance regulations require discriminatory testing of all transmissible spongiform encephalopathy (TSE)-positive small ruminant (SR) samples in order to classify them as bovine spongiform encephalopathy (BSE) or non-BSE. This requires a range of tests, including characterization by bioassay in mouse models. Since 2005, naturally occurring BSE has been identified in two goats. It has also been demonstrated that more than one distinct TSE strain can coinfect a single animal in natural field situations. This study assesses the ability of the statutory methods as listed in the regulation to identify BSE in a blinded series of brain samples, in which ovine BSE and distinct isolates of scrapie are mixed at various ratios ranging from 99% to 1%. Additionally, these current statutory tests were compared with a new in vitro discriminatory method, which uses serial protein misfolding cyclic amplification (sPMCA). Western blotting consistently detected 50% BSE within a mixture, but at higher dilutions it had variable success. The enzyme-linked immunosorbent assay (ELISA) method consistently detected BSE only when it was present as 99% of the mixture, with variable success at higher dilutions. Bioassay and sPMCA reported BSE in all samples where it was present, down to 1%. sPMCA also consistently detected the presence of BSE in mixtures at 0.1%. While bioassay is the only validated method that allows comprehensive phenotypic characterization of an unknown TSE isolate, the sPMCA assay appears to offer a fast and cost-effective alternative for the screening of unknown isolates when the purpose of the investigation was solely to determine the presence or absence of BSE.
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22
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Corda E, Thorne L, Beck KE, Lockey R, Green RB, Vickery CM, Holder TM, Terry LA, Simmons MM, Spiropoulos J. Ability of wild type mouse bioassay to detect bovine spongiform encephalopathy (BSE) in the presence of excess scrapie. Acta Neuropathol Commun 2015; 3:21. [PMID: 25853789 PMCID: PMC4382846 DOI: 10.1186/s40478-015-0194-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 02/05/2015] [Indexed: 11/10/2022] Open
Abstract
Introduction Scrapie and bovine spongiform encephalopathy (BSE) are transmissible spongiform encephalopathies (TSEs) which naturally affect small and large ruminants respectively. However, small ruminants, which are susceptible to BSE under experimental conditions, have been exposed to the same or similar contaminated food additives as cattle. To date two natural cases of BSE in small ruminants have been reported. As a result surveillance projects, combined with appropriate control measures, have been established throughout the European Union (EU) to minimize the overall incidence of small ruminant TSEs. Although BSE can be differentiated from classical scrapie (subsequently referred to as scrapie) if appropriate discriminatory tests are applied, the value of these tests in BSE/scrapie co-infection scenarios has not been evaluated fully. Mouse bioassay is regarded as the gold standard regarding differentiation of distinct TSE strains and has been used as to resolve TSE cases were laboratory tests produced equivocal results. However, the ability of this method to discriminate TSE strains when they co-exist has not been examined systematically. To address this issue we prepared in vitro mixtures of ovine BSE and scrapie and used them to challenge RIII, C57BL/6 and VM mice. Results Disease phenotype analysis in all three mouse lines indicated that most phenotypic parameters (attack rates, incubation periods, lesion profiles and Western blots) were compatible with scrapie phenotypes as were immunohistochemistry (IHC) data from RIII and C57BL/6 mice. However, in VM mice that were challenged with BSE/scrapie mixtures a single BSE-associated IHC feature was identified, indicating the existence of BSE in animals where the scrapie phenotype was dominant. Conclusions We conclude that wild type mouse bioassay is of limited value in detecting BSE in the presence of scrapie particularly if the latter is in relative excess. Electronic supplementary material The online version of this article (doi:10.1186/s40478-015-0194-2) contains supplementary material, which is available to authorized users.
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23
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Simmons MM, Moore SJ, Lockey R, Chaplin MJ, Konold T, Vickery C, Spiropoulos J. Phenotype shift from atypical scrapie to CH1641 following experimental transmission in sheep. PLoS One 2015; 10:e0117063. [PMID: 25710519 PMCID: PMC4339189 DOI: 10.1371/journal.pone.0117063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/18/2014] [Indexed: 11/19/2022] Open
Abstract
The interactions of host and infecting strain in ovine transmissible spongiform encephalopathies are known to be complex, and have a profound effect on the resulting phenotype of disease. In contrast to classical scrapie, the pathology in naturally-occurring cases of atypical scrapie appears more consistent, regardless of genotype, and is preserved on transmission within sheep homologous for the prion protein (PRNP) gene. However, the stability of transmissible spongiform encephalopathy phenotypes on passage across and within species is not absolute, and there are reports in the literature where experimental transmissions of particular isolates have resulted in a phenotype consistent with a different strain. In this study, intracerebral inoculation of atypical scrapie between two genotypes both associated with susceptibility to atypical forms of disease resulted in one sheep displaying an altered phenotype with clinical, pathological, biochemical and murine bioassay characteristics all consistent with the classical scrapie strain CH1641, and distinct from the atypical scrapie donor, while the second sheep did not succumb to challenge. One of two sheep orally challenged with the same inoculum developed atypical scrapie indistinguishable from the donor. This study adds to the range of transmissible spongiform encephalopathy phenotype changes that have been reported following various different experimental donor-recipient combinations. While these circumstances may not arise through natural exposure to disease in the field, there is the potential for iatrogenic exposure should current disease surveillance and feed controls be relaxed. Future sheep to sheep transmission of atypical scrapie might lead to instances of disease with an alternative phenotype and onward transmission potential which may have adverse implications for both public health and animal disease control policies.
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Affiliation(s)
- Marion M. Simmons
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
- * E-mail:
| | - S. Jo Moore
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Richard Lockey
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Melanie J Chaplin
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Timm Konold
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Christopher Vickery
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - John Spiropoulos
- Animal and Plant Health Agency—Weybridge, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
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Detection and discrimination of classical and atypical L-type bovine spongiform encephalopathy by real-time quaking-induced conversion. J Clin Microbiol 2015; 53:1115-20. [PMID: 25609728 DOI: 10.1128/jcm.02906-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Statutory surveillance of bovine spongiform encephalopathy (BSE) indicates that cattle are susceptible to both classical BSE (C-BSE) and atypical forms of BSE. Atypical forms of BSE appear to be sporadic and thus may never be eradicated. A major challenge for prion surveillance is the lack of sufficiently practical and sensitive tests for routine BSE detection and strain discrimination. The real-time quaking-induced conversion (RT-QuIC) test, which is based on prion-seeded fibrillization of recombinant prion protein (rPrPSen), is known to be highly specific and sensitive for the detection of multiple human and animal prion diseases but not BSE. Here, we tested brain tissue from cattle affected by C-BSE and atypical L-type bovine spongiform encephalopathy (L-type BSE or L-BSE) with the RT-QuIC assay and found that both BSE forms can be detected and distinguished using particular rPrPSen substrates. Specifically, L-BSE was detected using multiple rPrPSen substrates, while C-BSE was much more selective. This substrate-based approach suggests a diagnostic strategy for specific, sensitive, and rapid detection and discrimination of at least some BSE forms.
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Adkin A, Donaldson N, Kelly L. A quantitative assessment of the prion risk associated with wastewater from carcass-handling facilities. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2013; 33:1212-1227. [PMID: 23126436 DOI: 10.1111/j.1539-6924.2012.01921.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Wastewater from facilities processing livestock that may harbor transmissible spongiform encephalopathies (TSEs) infectivity is permitted under license for application to land where susceptible livestock may have access. Several previous risk assessments have investigated the risk of bovine spongiform encephalopathy (BSE) associated with wastewater effluents; however, the risk of exposure to classical scrapie and atypical scrapie has not been assessed. With the prevalence of certain TSEs (BSE in cattle and classical scrapie in sheep) steadily in decline, and with considerable changes in the structure of carcass-processing industries in Great Britain, a reappraisal of the TSE risk posed by wastewater is required. Our results indicate that the predicted number of new TSE infections arising from the spreading of wastewater on pasture over one year would be low, with a mean of one infection every 1,000 years for BSE in cattle (769, 555,556), and one infection every 30 years (16, 2,500), and 33 years (16, 3,333) for classical and atypical scrapie, respectively. It is assumed that the values and assumptions used in this risk assessment remain constant. For BSE in cattle the main contributors are abattoir and rendering effluent, contributing 35% and 22% of the total number of new BSE infections. For TSEs in sheep, effluent from small incinerators and rendering plants are the major contributors (on average 32% and 31% of the total number of new classical scrapie and atypical scrapie infections). This is a reflection of the volume of carcass material and Category 1 material flow through such facilities.
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Affiliation(s)
- Amie Adkin
- Epidemiology, Surveillance and Risk Group, Animal Health and Veterinary Laboratories Agency, Woodham Lane, Weybridge, KT15 3NB, UK.
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26
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Pirisinu L, Nonno R, Esposito E, Benestad SL, Gambetti P, Agrimi U, Zou WQ. Small ruminant nor98 prions share biochemical features with human gerstmann-sträussler-scheinker disease and variably protease-sensitive prionopathy. PLoS One 2013; 8:e66405. [PMID: 23826096 PMCID: PMC3691246 DOI: 10.1371/journal.pone.0066405] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 05/06/2013] [Indexed: 01/08/2023] Open
Abstract
Prion diseases are classically characterized by the accumulation of pathological prion protein (PrPSc) with the protease resistant C-terminal fragment (PrPres) of 27–30 kDa. However, in both humans and animals, prion diseases with atypical biochemical features, characterized by PK-resistant PrP internal fragments (PrPres) cleaved at both the N and C termini, have been described. In this study we performed a detailed comparison of the biochemical features of PrPSc from atypical prion diseases including human Gerstmann-Sträussler-Scheinker disease (GSS) and variably protease-sensitive prionopathy (VPSPr) and in small ruminant Nor98 or atypical scrapie. The kinetics of PrPres production and its cleavage sites after PK digestion were analyzed, along with the PrPSc conformational stability, using a new method able to characterize both protease-resistant and protease-sensitive PrPSc components. All these PrPSc types shared common and distinctive biochemical features compared to PrPSc from classical prion diseases such as sporadic Creutzfeldt-Jakob disease and scrapie. Notwithstanding, distinct biochemical signatures based on PrPres cleavage sites and PrPSc conformational stability were identified in GSS A117V, GSS F198S, GSS P102L and VPSPr, which allowed their specific identification. Importantly, the biochemical properties of PrPSc from Nor98 and GSS P102L largely overlapped, but were distinct from the other human prions investigated. Finally, our study paves the way towards more refined comparative approaches to the characterization of prions at the animal–human interface.
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Affiliation(s)
- Laura Pirisinu
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
- * E-mail: (LP); (WQZ)
| | - Romolo Nonno
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Elena Esposito
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | | | - Pierluigi Gambetti
- Department of Pathology, National Prion Disease Pathology Surveillance Center, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Umberto Agrimi
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
| | - Wen-Quan Zou
- Department of Pathology, National Prion Disease Pathology Surveillance Center, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- * E-mail: (LP); (WQZ)
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Meydan H, Özkan MM, Yildiz MA. Genetic risk assessment for atypical scrapie in Turkish native sheep breeds. Small Rumin Res 2013. [DOI: 10.1016/j.smallrumres.2012.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Beck KE, Thorne L, Lockey R, Vickery CM, Terry LA, Bujdoso R, Spiropoulos J. Strain typing of classical scrapie by transgenic mouse bioassay using protein misfolding cyclic amplification to replace primary passage. PLoS One 2013; 8:e57851. [PMID: 23472112 PMCID: PMC3589467 DOI: 10.1371/journal.pone.0057851] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/26/2013] [Indexed: 11/24/2022] Open
Abstract
According to traditional murine bioassay methodology, prions must be serially passaged within a new host before a stable phenotype, and therefore a strain, can be assigned. Prions often transmit with difficulty from one species to another; a property termed the transmission barrier. Transgenic mouse lines that over express prion protein (PrP) genes of different species can circumvent the transmission barrier but serial passages may still be required, particularly if unknown strains are encountered. Here we sought to investigate whether protein misfolding cyclic amplification (PMCA), an in-vitro method of PrPSc replication, could be used to replace serial passage of VRQ/VRQ classical scrapie isolates undergoing strain typing in ovine transgenic tg338 mice. Two classical scrapie field isolates that do not readily transmit to wild-type mice underwent bioassay in tg338 mice pre- and post- PMCA and the phenotype of disease in inoculated mice was compared. For one of the sources investigated, the PMCA product gave rise to the same disease phenotypes in tg338 mice as traditional bioassay, as indicated by lesion profile, IHC analysis and Western blot, whilst the second source produced phenotypic characteristics which were not identical with those that arose through traditional bioassay. These data show that differences in the efficiency of PMCA as a strain-typing tool may vary between ovine classical scrapie isolates and therefore suggest that the ability of PMCA to replace serial passage of classical scrapie in tg338 mice may depend on the strain present in the initial source.
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Affiliation(s)
- Katy E. Beck
- Transmissible Spongiform Encephalopathy Department, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom
| | - Leigh Thorne
- Transmissible Spongiform Encephalopathy Department, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom
| | - Richard Lockey
- Department of Pathology, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom
| | - Christopher M. Vickery
- Transmissible Spongiform Encephalopathy Department, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom
| | - Linda A. Terry
- Transmissible Spongiform Encephalopathy Department, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom
| | - Raymond Bujdoso
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - John Spiropoulos
- Department of Pathology, Animal Health and Veterinary Laboratories Agency, Addlestone, Surrey, United Kingdom
- * E-mail:
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Comparative performance of three TSE rapid tests for surveillance in healthy sheep affected by scrapie. J Virol Methods 2011; 173:161-8. [DOI: 10.1016/j.jviromet.2011.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/29/2010] [Accepted: 01/11/2011] [Indexed: 11/21/2022]
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Ortiz-Pelaez A, Bianchini J. The impact of the genotype on the prevalence of classical scrapie at population level. Vet Res 2011; 42:31. [PMID: 21324113 PMCID: PMC3055824 DOI: 10.1186/1297-9716-42-31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Accepted: 02/15/2011] [Indexed: 12/02/2022] Open
Abstract
Total number and genotypes of animals in holdings selected for the genotype & cull option in the Compulsory Scrapie Flock Scheme (CSFS) in Great Britain were extracted from the National Scrapie Plan data warehouse. The association between various genotype-related measures and scrapie prevalence infection was tested using zero-inflated negative binomial models with the counts of positive cases as dependent variable, and country, number of flocks in the scheme, flock size, surveillance source and the following genotype-related measurements: the centered-log ratios (clr) oof the 15 genotypes, of the proportions of the 5 alleles at codons 136, 154 and 171, of the proportions of the 5 NSP types, and two flock-susceptibility risk indicators, as explanatory variables. A total of 319341 genotyped animals from 168 holdings were included in the analysis. An increased proportion of the ARR/ARR genotype corresponded to a decrease in the number of scrapie cases. ARR/AHQ, AHQ/VRQ, ARH/VRQ and ARQ/VRQ genotypes, NSP type V, ARH, ARQ, AHQ and VRQ alleles and the low and high-susceptibility risk indicators are all associated with an increase risk in the number of scrapie cases. Regardless the management practices; the increased susceptibility that the non-ARR alleles confer on an individual could be extrapolated at the population level. Increasing prevalence of ARR allele reduces the overall risk of scrapie at population level. At genotype level, the VRQ/VRQ genotype, present a very low frequency in the study population, seems to play a residual effect in the overall risk of scrapie in a flock.
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Affiliation(s)
- Angel Ortiz-Pelaez
- Centre for Epidemiology and Risk Analysis, Veterinary Laboratories Agency, Woodham Lane, Weybridge, UK.
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Thackray AM, Hopkins L, Lockey R, Spiropoulos J, Bujdoso R. Emergence of multiple prion strains from single isolates of ovine scrapie. J Gen Virol 2011; 92:1482-1491. [PMID: 21270287 DOI: 10.1099/vir.0.028886-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The infectious agent associated with prion diseases such as ovine scrapie shows strain diversity. Ovine prion strains have typically been identified by their transmission properties in wild-type mice. However, strain typing of ovine scrapie isolates in wild-type mice may not reveal properties of the infectious prion agent as they exist in the original host. This could be circumvented if ovine scrapie isolates are passaged in ovine prion protein (PrP)-transgenic mice. This study used incubation time, lesion profile, immunohistochemistry of the disease-associated PrP (PrP(Sc)) and molecular profile to compare the range of ovine prion strains that emerged from sheep scrapie isolates following serial passage in wild-type and ovine PrP transgenic mice. It was found that a diverse range of ovine prion strains emerged from homozygous ARQ and VRQ scrapie isolates passaged in wild-type and ovine PrP transgenic mice. However, strain-specific PrP(Sc) deposition and PrP27-30 molecular profile patterns were identified in ovine PrP transgenic mice that were not detected in wild-type mice. Significantly, it was established that the individual mouse brain selected for transmission during prion strain typing had a significant influence on strain definition. Serial passage of short- and long-incubation-time animals from the same group of scrapie-inoculated mice revealed different prion strain phenotypes. These observations are consistent with the possibility that some scrapie isolates contain more than one prion strain.
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Affiliation(s)
- Alana M Thackray
- University of Cambridge, Department of Veterinary Medicine, Madingley Road, Cambridge CB3 0ES, UK
| | - Lee Hopkins
- University of Cambridge, Department of Veterinary Medicine, Madingley Road, Cambridge CB3 0ES, UK
| | - Richard Lockey
- Veterinary Laboratories Agency, Department of Pathology and Host Susceptibility, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - John Spiropoulos
- Veterinary Laboratories Agency, Department of Pathology and Host Susceptibility, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, UK
| | - Raymond Bujdoso
- University of Cambridge, Department of Veterinary Medicine, Madingley Road, Cambridge CB3 0ES, UK
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Joint Scientific Opinion on any possible epidemiological or molecular association between TSEs in animals and humans. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.1945] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Abstract
Although prion diseases, such as Creutzfeldt-Jakob disease (CJD) in humans and scrapie in sheep, have long been recognized, our understanding of their epidemiology and pathogenesis is still in its early stages. Progress is hampered by the lengthy incubation periods and the lack of effective ways of monitoring and characterizing these agents. Protease-resistant conformers of the prion protein (PrP), known as the "scrapie form" (PrP(Sc)), are used as disease markers, and for taxonomic purposes, in correlation with clinical, pathological, and genetic data. In humans, prion diseases can arise sporadically (sCJD) or genetically (gCJD and others), caused by mutations in the PrP-gene (PRNP), or as a foodborne infection, with the agent of bovine spongiform encephalopathy (BSE) causing variant CJD (vCJD). Person-to-person spread of human prion disease has only been known to occur following cannibalism (kuru disease in Papua New Guinea) or through medical or surgical treatment (iatrogenic CJD, iCJD). In contrast, scrapie in small ruminants and chronic wasting disease (CWD) in cervids behave as infectious diseases within these species. Recently, however, so-called atypical forms of prion diseases have been discovered in sheep (atypical/Nor98 scrapie) and in cattle, BSE-H and BSE-L. These maladies resemble sporadic or genetic human prion diseases and might be their animal equivalents. This hypothesis also raises the significant public health question of possible epidemiological links between these diseases and their counterparts in humans.
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A new method for the characterization of strain-specific conformational stability of protease-sensitive and protease-resistant PrPSc. PLoS One 2010; 5:e12723. [PMID: 20856860 PMCID: PMC2939050 DOI: 10.1371/journal.pone.0012723] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 08/02/2010] [Indexed: 11/24/2022] Open
Abstract
Although proteinacious in nature, prions exist as strains with specific self-perpetuating biological properties. Prion strains are thought to be associated with different conformers of PrPSc, a disease-associated isoform of the host-encoded cellular protein (PrPC). Molecular strain typing approaches have been developed which rely on the characterization of protease-resistant PrPSc. However, PrPSc is composed not only of protease-resistant but also of protease-sensitive isoforms. The aim of this work was to develop a protocol for the molecular characterization of both, protease-resistant and protease-sensitive PrPSc aggregates. We first set up experimental conditions which allowed the most advantageous separation of PrPC and PrPSc by means of differential centrifugation. The conformational solubility and stability assay (CSSA) was then developed by measuring PrPSc solubility as a function of increased exposure to GdnHCl. Brain homogenates from voles infected with human and sheep prion isolates were analysed by CSSA and showed strain-specific conformational stabilities, with mean [GdnHCl]1/2 values ranging from 1.6 M for MM2 sCJD to 2.1 for scrapie and to 2.8 M for MM1/MV1 sCJD and E200K gCJD. Interestingly, the rank order of [GdnHCl]1/2 values observed in the human and sheep isolates used as inocula closely matched those found following transmission in voles, being MM1 sCJD the most resistant (3.3 M), followed by sheep scrapie (2.2 M) and by MM2 sCJD (1.6 M). In order to test the ability of CSSA to characterise protease-sensitive PrPSc, we analysed sheep isolates of Nor98 and compared them to classical scrapie isolates. In Nor98, insoluble PrPSc aggregates were mainly protease-sensitive and showed a conformational stability much lower than in classical scrapie. Our results show that CSSA is able to reveal strain-specified PrPSc conformational stabilities of protease-resistant and protease-sensitive PrPSc and that it is a valuable tool for strain typing in natural hosts, such as humans and sheep.
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