STUDY OF ATYPICAL BSE 2010 Annual Report May 2011
2010 Annual Report
1a.Objectives (from AD-416) The objective of this cooperative research project with Dr. Maria Caramelli from the Italian BSE Reference Laboratory in Turin, Italy, is to conduct comparative studies with the U.S. bovine spongiform encephalopathy (BSE) isolate and the atypical BSE isolates identified in Italy. The studies will cover the following areas: 1. Evaluation of present diagnostics tools used in the U.S. for the detection of atypical BSE cases. 2. Molecular comparison of the U.S. BSE isolate and other typical BSE isolates with atypical BSE cases. 3. Studies on transmissibility and tissue distribution of atypical BSE isolates in cattle and other species.
1b.Approach (from AD-416) This project will be done as a Specific Cooperative Agreement with the Italian BSE Reference Laboratory, Istituto Zooprofilattico Sperimentale del Piemonte, in Turin, Italy. It is essential for the U.S. BSE surveillance program to analyze the effectiveness of the U.S diagnostic tools for detection of atypical cases of BSE. Molecular comparisons of the U.S. BSE isolate with atypical BSE isolates will provide further characterization of the U.S. BSE isolate. Transmission studies are already underway using brain homogenates from atypical BSE cases into mice, cattle and sheep. It will be critical to see whether the atypical BSE isolates behave similarly to typical BSE isolates in terms of transmissibility and disease pathogenesis. If transmission occurs, tissue distribution comparisons will be made between cattle infected with the atypical BSE isolate and the U.S. BSE isolate. Differences in tissue distribution could require new regulations regarding specific risk material (SRM) removal.
3.Progress Report This report documents research conducted under a Specific Cooperative Agreement between ARS and the IST ZOOPROFIL SPERIMENT PIEMONTE. Additional details for the research can be found in the report for the parent project 3625-32000-086-00D, TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES
The aim of the cooperative research project was to: 1. Evaluate present diagnostic tools used in the U.S. for the detection of atypical bovine spongiform encephalopathy (BSE) cases. 2. Perform molecular comparison of the U.S. BSE isolate and other typical BSE isolates with atypical BSE cases. 3. Support studies on transmissibility and tissue distribution of atypical BSE isolates in cattle and other species. To complete objectives 1 and 2 (i.e., to compare Italian and U.S. BSE confirmatory protocols for detection of classical (C-) and atypical (H- and L-type) BSE cases), samples of Italian C-BSE and Italian L-type BSE (BASE), both frozen and formalin fixed, were sent to USDA laboratories in Ames, Iowa, to undergo Western blot (WB) and immunohistochemistry (IHC) comparison studies for PrPSc detection according to U.S. and Italian methods. A Western blot expert from the cooperating Italian lab assisted ARS scientists in performing the protocols from each laboratory in parallel. A comparative IHC study between U.S. and Italian BSE confirmatory protocols was also performed when the collaborator sent a scientist to Ames to assist in performing the Italian IHC protocol on BSE samples chosen for the study. Results obtained showed the Italian and U.S. IHC procedures were alike in PrPSc detection regarding its tissue distribution, deposition pattern and intensity of staining on all the C-, L- and H-type BSE cases considered. In addition, the U.S. protocol evidenced the characteristic presence of plaques in the frontal cortex of the Italian BASE case similar to the Italian protocol. Data from studies on objectives 1 & 2 has been presented at several international meetings in 2008 and 2009, and has been finalized into manuscript form for publication in a peer-reviewed journal (Journal of Veterinary Diagnostic Investigation). In support of objective 3, the cooperators completed and published their transmissibility and tissue distribution work on BASE cases in a peer-reviewed journal in 2008 (PLoS Pathogens Volume 4, page e1000075). They reported that in all experimentally infected atypical BSE animals, no PrPSc was detected in peripheral tissues either by standard Western blot analysis or following phosphotungstic acid precipitation. Peripheral issues examined included cervical and mesenteric lymph nodes, spleen, thymus, liver, lung, peripheral nerves, and forelimb and hind limb muscles. These findings support the conclusion there is no scientific evidence to expand the list of tissues included in the Specified Risk Material ban based on atypical BSE research data, thus confirming other studies indicating the pathogenesis of BSE in cattle is fundamentally different from that in sheep and mice, due to an exclusive intraneuronal spread of infectivity from the gut to the central nervous system. Methods used for monitoring included email, site visits, and periodic written reports.
They reported that in all experimentally infected atypical BSE animals, no PrPSc was detected in peripheral tissues either by standard Western blot analysis or following phosphotungstic acid precipitation. Peripheral issues examined included cervical and mesenteric lymph nodes, spleen, thymus, liver, lung, peripheral nerves, and forelimb and hind limb muscles. These findings support the conclusion there is no scientific evidence to expand the list of tissues included in the Specified Risk Material ban based on atypical BSE research data, thus confirming other studies indicating the pathogenesis of BSE in cattle is fundamentally different from that in sheep and mice, due to an exclusive intraneuronal spread of infectivity from the gut to the central nervous system. Methods used for monitoring included email, site visits, and periodic written reports.
Saturday, June 12, 2010
PUBLICATION REQUEST AND FOIA REQUEST Project Number: 3625-32000-086-05 Study of Atypical Bse
Wednesday, July 28, 2010
re-Freedom of Information Act Project Number 3625-32000-086-05, Study of Atypical BSE UPDATE July 28, 2010
Thursday, June 24, 2010
Accumulation of L-type Bovine Prions in Peripheral Nerve Tissues Volume 16, Number 7–July 2010
Accumulation of L-type Bovine Prions in Peripheral Nerve Tissues
Yoshifumi Iwamaru, Morikazu Imamura, Yuichi Matsuura, Kentaro Masujin, Yoshihisa Shimizu, Yujing Shu, Megumi Kurachi, Kazuo Kasai, Yuichi Murayama, Shigeo Fukuda, Sadao Onoe, Ken'ichi Hagiwara, Yoshio Yamakawa, Tetsutaro Sata, Shirou Mohri, Hiroyuki Okada, and Takashi Yokoyama Author affiliations: National Institute of Animal Health, Tsukuba, Ibaraki, Japan (Y. Iwamaru, M. Imamura, Y. Matsuura, K. Masujin, Y. Shimizu, Y. Shu, M. Kurachi, K. Kasai, Y. Murayama, S. Mohri, H. Okada, T. Yokoyama); Hokkaido Animal Research Center, Hokkaido, Japan (S. Fukuda, S. Onoe); and National Institute of Infectious Diseases, Tokyo, Japan (K. Hagiwara, Y. Yamakawa, T. Sata)
Suggested citation for this article
Abstract We recently reported the intraspecies transmission of L-type atypical bovine spongiform encephalopathy (BSE). To clarify the peripheral pathogenesis of L-type BSE, we studied prion distribution in nerve and lymphoid tissues obtained from experimentally challenged cattle. As with classical BSE prions, L-type BSE prions accumulated in central and peripheral nerve tissues.
Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disorder of cattle characterized by accumulation of a protease-resistant form of a normal cellular prion protein (PrPres) in the central nervous system. The scientific literature in general has assumed that BSE in cattle is caused by a uniform strain (classical BSE). However, different neuropathologic and molecular phenotypes of BSE (atypical BSEs) have recently been reported from various countries (1). Recent data from Western blot analyses of field cases of atypical BSEs are characterized by a higher (H-type BSE) or lower (L-type BSE) molecular mass of the unglycosylated form of PrPres than is classical BSE (2). The origins of atypical BSEs remain obscure; unlike classical BSE, atypical BSE has been detected mainly in aged cattle and suggested a as possible sporadic form of BSE (3).
Several lines of evidence demonstrate that classical BSE and a variant form of Creutzfeldt-Jacob disease are most likely caused by the same agent (4,5). Transmission of classical BSE to humans has been proposed to result from ingestion of contaminated food. Whether atypical BSEs are transmissible to humans remains uncertain; however, human susceptibility to L-type BSEs is suggested by recent experimental transmission in primates (6) and mice transgenic for human prion protein (PrP) (7) by using the most effective route of intracerebral inoculations of prions. The L-type BSE prion is much more virulent in primates and in humanized mice than is the classical BSE prion, which suggests the possibility of zoonotic risk associated with the L-type BSE prion. These findings emphasize the critical importance of understanding tissue distribution of L-type BSE prions in cattle because, among the current administrative measures for BSE controls, the specified risk materials removal policy plays a crucial role in consumer protection.
In Japan, atypical BSE was detected in an aged Japanese Black cow (BSE/JP24) (8). We recently reported the successful transmission of BSE/JP24 prions to cattle and showed that the characteristics of these prions closely resemble those of L-type BSE prions found in Italy (9). In this study, we report the peripheral distribution of L-type BSE prions in experimentally challenged cattle.
Conclusions We report accumulation of L-type atypical BSE prions in peripheral nerve tissues sampled from intracerebrally challenged cattle. Our study demonstrated that almost all of the peripheral nerve tissues tested became PrPres positive in a time-dependent manner, whereas no PrPres was detectable in lymphoid tissues, even in cattle with fatal atypical BSE. Our results suggest the possibility that, like classical BSE prions, L-type BSE prions propagated in the central nervous system and were spread centrifugally by nerve pathways (11,12). In Italy, L-type BSE prions have been characterized in detail by using cattle challenged intracerebrally. However, PrPres was not detected in their peripheral tissues, including the peripheral nerves (13). The reason for the discrepancy in PrPres detection is unclear. In view of the similarities between the L-type and BSE/JP24 prion characteristics (9), this discrepancy may result from differences in the methods used for PrPres detection.
We detected infectivity in the nerve tissue samples (including samples from the obex, sciatic nerve, adrenal gland, brachial nerve plexus, and vagus nerve) obtained 10, 12, and 16 mpi. On the basis of the incubation time of 223 ± 25 (mean ± SD) days in mice injected with a 1,000-fold dilution of the obex homogenate, infectious titers in peripheral nerve tissues appeared to be 1,000 × lower than those estimated in the obex during endpoint titration of infectivity.
Our results demonstrate that L-type atypical BSE prions can be distributed in the peripheral nerve tissues of intracerebrally challenged cattle. These findings are useful for understanding L-type BSE pathogenesis and accurately assessing the risks associated with this disease. Investigations of prion distribution in cattle that have been orally challenged with L-type BSE prions are critical.
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Originally published as JGV in Press, 10.1099/vir.0.025387-0 on October 13, 2010 J Gen Virol 92 (2011), 467-476; DOI 10.1099/vir.0.025387-0
BSE infectivity in the absence of detectable PrPSc accumulation in the tongue and nasal mucosa of terminally diseased cattle
Anne Balkema-Buschmann, Martin Eiden, Christine Hoffmann, Martin Kaatz, Ute Ziegler, Markus Keller and Martin H. Groschup
Friedrich-Loeffler-Institut, Institute for Novel and Emerging Infectious Diseases, Südufer 10, 17493 Greifswald – Insel Riems, Germany
Correspondence Anne Balkema-Buschmann firstname.lastname@example.org
The pathogenesis of bovine spongiform encephalopathy (BSE) infections in cattle has been studied in recent years by using highly sensitive transgenic-mouse bioassays. It has been shown that in this species, the BSE agent amplifies almost exclusively in the central and peripheral nervous system. Even in animals that were killed in the clinical end stage of the disease, the lymphoreticular system was shown to be free of the infectious agent. No other animal species investigated to date exhibits such a restricted BSE-infectivity distribution pattern. However, there is growing evidence for a radial spread of infection from the central nervous system (CNS) into the periphery during the late stages of the disease. In this study, we challenged transgenic mice overexpressing the bovine prion protein with homogenates prepared from a wide variety of tissue samples collected from BSE-infected cattle. As prion infections involve the conversion of the cellular prion protein into its abnormally folded isoform (PrPSc), we applied various detection methods, such as the purification of scrapie-associated fibrils, immunohistochemistry, and the protein misfolding cyclic amplification technique. Despite negative results using these highly sensitive biochemical methods, we were, for the first time, able to detect BSE infectivity in the tongue and in the nasal mucosa of terminally diseased BSE field cases as well as experimentally challenged cattle by transgenic-mouse bioassay. This shows that BSE infectivity can be present in the peripheral tissues of terminally diseased cattle, including tissues used for human consumption.
Saturday, January 29, 2011
Atypical L-Type Bovine Spongiform Encephalopathy (L-BSE) Transmission to Cynomolgus Macaques, a Non-Human Primate
Jpn. J. Infect. Dis., 64 (1), 81-84, 2011
Wednesday, March 31, 2010
Atypical BSE in Cattle
To date the OIE/WAHO assumes that the human and animal health standards set out in the BSE chapter for classical BSE (C-Type) applies to all forms of BSE which include the H-type and L-type atypical forms. This assumption is scientifically not completely justified and accumulating evidence suggests that this may in fact not be the case. Molecular characterization and the spatial distribution pattern of histopathologic lesions and immunohistochemistry (IHC) signals are used to identify and characterize atypical BSE. Both the L-type and H-type atypical cases display significant differences in the conformation and spatial accumulation of the disease associated prion protein (PrPSc) in brains of afflicted cattle. Transmission studies in bovine transgenic and wild type mouse models support that the atypical BSE types might be unique strains because they have different incubation times and lesion profiles when compared to C-type BSE.
When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE. In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.
This study will contribute to a correct definition of specified risk material (SRM) in atypical BSE. The incumbent of this position will develop new and transfer existing, ultra-sensitive methods for the detection of atypical BSE in tissue of experimentally infected cattle.
please see all seven threats listed in the USA, and more...FULL TEXT ;
Thursday, August 12, 2010
Seven main threats for the future linked to prions
The TSE road map defining the evolution of European policy for protection against prion diseases is based on a certain numbers of hypotheses some of which may turn out to be erroneous. In particular, a form of BSE (called atypical Bovine Spongiform Encephalopathy), recently identified by systematic testing in aged cattle without clinical signs, may be the origin of classical BSE and thus potentially constitute a reservoir, which may be impossible to eradicate if a sporadic origin is confirmed. ***Also, a link is suspected between atypical BSE and some apparently sporadic cases of Creutzfeldt-Jakob disease in humans. These atypical BSE cases constitute an unforeseen first threat that could sharply modify the European approach to prion diseases.
14th ICID International Scientific Exchange Brochure -
Final Abstract Number: ISE.114
Session: International Scientific Exchange
Transmissible Spongiform encephalopathy (TSE) animal and human TSE in North America
update October 2009
Bacliff, TX, USA
An update on atypical BSE and other TSE in North America. Please remember, the typical U.K. c-BSE, the atypical l-BSE (BASE), and h-BSE have all been documented in North America, along with the typical scrapie's, and atypical Nor-98 Scrapie, and to date, 2 different strains of CWD, and also TME. All these TSE in different species have been rendered and fed to food producing animals for humans and animals in North America (TSE in cats and dogs ?), and that the trading of these TSEs via animals and products via the USA and Canada has been immense over the years, decades.
12 years independent research of available data
I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2009. With all the science to date refuting it, to continue to validate this old myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, medical i.e., surgical, blood, dental, endoscopy, optical, nutritional supplements, cosmetics etc.
I would like to submit a review of past CJD surveillance in the USA, and the urgent need to make all human TSE in the USA a reportable disease, in every state, of every age group, and to make this mandatory immediately without further delay. The ramifications of not doing so will only allow this agent to spread further in the medical, dental, surgical arena's. Restricting the reporting of CJD and or any human TSE is NOT scientific. Iatrogenic CJD knows NO age group, TSE knows no boundaries. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Gajdusek, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route.
Quantification of PrPC in bovine peripheral tissues: Analysis in wild-type and PrPC-deficient cattle
Authors: Shin-Ichi Kobayashi, Yasuhisa Ano, Akikazu Sakudo, Masayoshi Yukawa, Katsuaki Sigiura, Noboru Manabe, Hiroyuki Nakayama, Takashi Onodera
Affiliations: School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
Abstract: Cellular PrP (PrPC) is necessary for bovine spongiform encephalopathy (BSE) infection. The purpose of the present experiment was the quantification of PrPC in peripheral tissues to assess the risk of BSE infection from these tissues. The tissue distribution of PrPC was examined by a sandwich enzyme-linked immunosorbent assay (sELISA) and histochemical analysis. PrPC-deficient cows were used as a negative control. The sELISA revealed that the brain contained the highest PrPC content (10.7 µg/g tissue), while other organs/tissues harbored lower amounts, in decreasing order as follows: longissimus capitis muscle, iliocostalis thoracis muscle, splenius muscle, biceps femoris muscle, triceps brachii muscle, longissimus thoracis muscle, ileum, jejunum, duodenum, colon, cecum, apex linguae, omotransversarius muscle, posterior part of the corpus linguae, anterior part of the corpus linguae and radix linguae (5.2- to 31-fold less PrPC than the brain). In the tissue/organs of PrP-deficient cows, PrPC levels were under the limit of detection. Histochemical analysis showed that PrPC was expressed in nerve cells in intestinal tissues. The presence of PrPC in the bovine tongue, skeletal muscles and intestines raises the possibility of PrPSc accumulation in these tissues, indicating that these organs/tissues may serve as potential sources of BSE infection.
Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate
Emmanuel E. Comoy1*, Cristina Casalone2, Nathalie Lescoutra-Etchegaray1, Gianluigi Zanusso3, Sophie Freire1, Dominique Marcé1, Frédéric Auvré1, Marie-Magdeleine Ruchoux1, Sergio Ferrari3, Salvatore Monaco3, Nicole Salès4, Maria Caramelli2, Philippe Leboulch1,5, Paul Brown1, Corinne I. Lasmézas4, Jean-Philippe Deslys1
1 Institute of Emerging Diseases and Innovative Therapies, CEA, Fontenay-aux-Roses, France, 2 Istituto Zooprofilattico Sperimentale del Piemonte, Turin, Italy, 3 Policlinico G.B. Rossi, Verona, Italy, 4 Scripps Florida, Jupiter, Florida, United States of America, 5 Genetics Division, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
Abstract Top Background Human variant Creutzfeldt-Jakob Disease (vCJD) results from foodborne transmission of prions from slaughtered cattle with classical Bovine Spongiform Encephalopathy (cBSE). Atypical forms of BSE, which remain mostly asymptomatic in aging cattle, were recently identified at slaughterhouses throughout Europe and North America, raising a question about human susceptibility to these new prion strains.
Methodology/Principal Findings Brain homogenates from cattle with classical BSE and atypical (BASE) infections were inoculated intracerebrally into cynomolgus monkeys (Macacca fascicularis), a non-human primate model previously demonstrated to be susceptible to the original strain of cBSE. The resulting diseases were compared in terms of clinical signs, histology and biochemistry of the abnormal prion protein (PrPres). The single monkey infected with BASE had a shorter survival, and a different clinical evolution, histopathology, and prion protein (PrPres) pattern than was observed for either classical BSE or vCJD-inoculated animals. Also, the biochemical signature of PrPres in the BASE-inoculated animal was found to have a higher proteinase K sensitivity of the octa-repeat region. We found the same biochemical signature in three of four human patients with sporadic CJD and an MM type 2 PrP genotype who lived in the same country as the infected bovine.
Conclusion/Significance Our results point to a possibly higher degree of pathogenicity of BASE than classical BSE in primates and also raise a question about a possible link to one uncommon subset of cases of apparently sporadic CJD. Thus, despite the waning epidemic of classical BSE, the occurrence of atypical strains should temper the urge to relax measures currently in place to protect public health from accidental contamination by BSE-contaminated products.
Citation: Comoy EE, Casalone C, Lescoutra-Etchegaray N, Zanusso G, Freire S, et al. (2008) Atypical BSE (BASE) Transmitted from Asymptomatic Aging Cattle to a Primate. PLoS ONE 3(8): e3017. doi:10.1371/journal.pone.0003017
Editor: Neil Mabbott, University of Edinburgh, United Kingdom
Received: April 24, 2008; Accepted: August 1, 2008; Published: August 20, 2008
Copyright: © 2008 Comoy et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work has been supported by the Network of Excellence NeuroPrion.
Competing interests: CEA owns a patent covering the BSE diagnostic tests commercialized by the company Bio-Rad.
* E-mail: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000110/!x-usc:mailto:email@example.com
BASE Transmitted to Primates and MV2 sCJD Subtype Share PrP27-30 and PrPSc C-terminal Truncated Fragments
Zanusso, G1; Commoy, E2; Fasoli, E3; Fiorini, M3; Lescoutra, N4; Ruchoux, MM4; Casalone, C5; Caramelli, M5; Ferrari, S3; Lasmezas, C6; Deslys, J-P4; Monaco, S3 1University of Verona, of Neurological and Visual Sciences, Italy; 2CEA, IMETI/SEPIA, France; 3University of Verona, Neurological and Visual Sciences, Italy; 4IMETI/SEPIA, France; 5IZSPLVA, Italy; 6The Scripps Research Insitute, USA
The etiology of sporadic Creutzfeldt-Jakob disease (sCJD), the most frequent human prion disease, remains still unknown. The marked disease phenotype heterogeneity observed in sCJD is thought to be influenced by the type of proteinase K-resistant prion protein, or PrPSc (type 1 or type 2 according to the electrophoretic mobility of the unglycosylated backbone), and by the host polymorphic Methionine/Valine (M/V) codon 129 of the PRNP. By using a two-dimensional gel electrophoresis (2D-PAGE) and imunoblotting we previously showed that in sCJD, in addition to the PrPSc type, distinct PrPSc C-terminal truncated fragments (CTFs) correlated with different sCJD subtypes. Based on the combination of CTFs and PrPSc type, we distinguished three PrPSc patterns: (i) the first was observed in sCJD with PrPSc type 1 of all genotypes,; (ii) the second was found in M/M-2 (cortical form); (iii) the third in amyloidogenic M/V- 2 and V/V-2 subtypes (Zanusso et al., JBC 2004) . Recently, we showed that sCJD subtype M/V-2 shared molecular and pathological features with an atypical form of BSE, named BASE, thus suggesting a potential link between the two conditions. This connection was further confirmed after 2D-PAGE analysis, which showed an identical PrPSc signature, including the biochemical pattern of CTFs. To pursue this issue, we obtained brain homogenates from Cynomolgus macaques intracerebrally inoculated with brain homogenates from BASE. Samples were separated by using a twodimensional electrophoresis (2D-PAGE) followed by immunoblotting. ***We here show that the PrPSc pattern obtained in infected primates is identical to BASE and sCJD MV-2 subtype. These data strongly support the link, or at least a common ancestry, between a sCJD subtype and BASE. This work was supported by Neuroprion (FOOD-CT-2004-506579)
Transmission of Italian BSE and BASE Isolates in Cattle Results into a Typical BSE Phenotype and a Muscle Wasting Disease
Zanusso, G1; Lombardi, G2; Casalone, C3; D'Angelo, A4; Gelmetti, D2; Torcoli, G2; Barbieri, I2; Corona, C3; Fasoli, E1; Farinazzo, A1; Fiorini, M1; Gelati, M1; Iulini, B3; Tagliavini, F5; Ferrari, S1; Monaco, S1; Caramelli, M3; Capucci, L2 1University of Verona, Neurological and Visual Sciences, Italy; 2IZSLER, Italy; 3IZSPLVA, Italy; 4University of Turin, Animal Pathology, Italy; 5Isituto Carlo Besta, Italy
The clinical phenotype of bovine spongiform encephalopathy has been extensively reported in early accounts of the disorder. Following the introduction of statutory active surveillance, almost all BSE cases have been diagnosed on a pathological/molecular basis, in a pre-symptomatic clinical stage. In recent years, the active surveillance system has uncovered atypical BSE cases, which are characterized by distinct conformers of the PrPSc, named high-type (BSE-H) and low-type (BSE-L), whose clinicopathological phenotypes remain unknown. We recently reported two Italian atypical cases with a PrPSc type similar to BSE-L, pathologically characterized by PrP amyloid plaques. Experimental transmission to TgBov mice has recently disclosed that BASE is caused by a distinct prion strain which is extremely virulent. A major limitation of transmission studies to mice is the lack of reliable information on clinical phenotype of BASE in its natural host. In the present study, we experimentally infected Fresian/Holstein and Alpine/Brown cattle with Italian BSE and BASE isolates by i.c. route. BASE infected cattle showed survival times significantly shorter than BSE, a finding more readily evident in Fresian/Holstein, and in keeping with previous observations in TgBov mice. Clinically, BSE-infected cattle developed a disease phenotype highly comparable with that described in field BSE cases and in experimentally challenged cattle. On the contrary, BASE-inoculated cattle developed an amyotrophic disorder accompanied by mental dullness. The molecular and neuropathological profiles, including PrP deposition pattern, closely matched those observed in the original cases. ***This study further confirms that BASE is caused by a distinct prion isolate and discloses a novel disease phenotype in cattle, closely resembling the phenotype previous reported in scrapie-inoculated cattle and in some subtypes of inherited and sporadic Creutzfeldt-Jakob disease.
Molecular Features of the Protease-resistant Prion Protein (PrPres) in H-type BSE
Biacabe, A-G1; Jacobs, JG2; Gavier-Widén, D3; Vulin, J1; Langeveld, JPM2; Baron, TGM1 1AFSSA, France; 2CIDC-Lelystad, Netherlands; 3SVA, Sweden
Western blot analyses of PrPres accumulating in the brain of BSE-infected cattle have demonstrated 3 different molecular phenotypes regarding to the apparent molecular masses and glycoform ratios of PrPres bands. We initially described isolates (H-type BSE) essentially characterized by higher PrPres molecular mass and decreased levels of the diglycosylated PrPres band, in contrast to the classical type of BSE. This type is also distinct from another BSE phenotype named L-type BSE, or also BASE (for Bovine Amyloid Spongiform Encephalopathy), mainly characterized by a low representation of the diglycosylated PrPres band as well as a lower PrPres molecular mass. Retrospective molecular studies in France of all available BSE cases older than 8 years old and of part of the other cases identified since the beginning of the exhaustive surveillance of the disease in 20001 allowed to identify 7 H-type BSE cases, among 594 BSE cases that could be classified as classical, L- or H-type BSE. By Western blot analysis of H-type PrPres, we described a remarkable specific feature with antibodies raised against the C-terminal region of PrP that demonstrated the existence of a more C-terminal cleaved form of PrPres (named PrPres#2 ), in addition to the usual PrPres form (PrPres #1). In the unglycosylated form, PrPres #2 migrates at about 14 kDa, compared to 20 kDa for PrPres #1. The proportion of the PrPres#2 in cattle seems to by higher compared to the PrPres#1. Furthermore another PK-resistant fragment at about 7 kDa was detected by some more N-terminal antibodies and presumed to be the result of cleavages of both N- and C-terminal parts of PrP. These singular features were maintained after transmission of the disease to C57Bl/6 mice. ***The identification of these two additional PrPres fragments (PrPres #2 and 7kDa band) reminds features reported respectively in sporadic Creutzfeldt-Jakob disease and in Gerstmann-Sträussler-Scheinker (GSS) syndrome in humans.
And last but not least, similarities of PrPres between Htype BSE and human prion diseases like CJD or GSS have been put forward , as well as between L-type BSE and CJD . These findings raise questions about the origin and inter species transmission of these prion diseases that were discovered through the BSE active surveillance.
full text 18 pages ;
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Transmission of atypical BSE in humanized mouse models
Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 1Case Western Reserve University, USA; 2Instituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University (Previously at USDA National Animal Disease Center), USA
Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were largely undefined.
Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice. Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.
Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time.*** The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.
Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice. BSE-H is also transmissible in our humanized Tg mice. The possibility of more than two atypical BSE strains will be discussed.
Supported by NINDS NS052319, NIA AG14359, and NIH AI 77774.
Analysis of Bovine Prion Protein Gene Sequence Variation in Animals with Classical and Atypical BSE
Polak, MP; Larska, M; Rola, J; Zmudzinski, JF National Veterinary Research Institute, Department of Virology, Poland B.
Variation within prion protein gene sequence have major impact on the susceptibility to prion diseases in humans and sheep. However no major differences between healthy cattle and bovine spongiform encephalopathy (BSE) affected individuals were identified. Recent studies indicate that susceptibility to bovine spongiform encephalopathy is associated with 23-base pair (bp) and 12-bp indel sequences. Identification of atypical BSE in older cattle in several countries pointed at the possibility of spontaneous origin of this new form of prion disease due to possible mutations within prion gene (PRNP) sequence. A./O. Therefore the aim of the study was to analyze and to compare prion protein gene sequences in animals showing classical and atypical BSE for any genetic traits differentating both forms of the disease. M. Analysis included: octapeptide-repeat polymorphism; sequence analysis of exon 3 region; deletion/insertion polymorphism within the promoter sequence (23-bp), intron 1 (12-bp) and 3'untranslated region - UTR (14-bp) of PRNP gene. R. No major differences were found as for the octapeptide-repeats. Most dominant genotype in both classical and atypical BSE involved 6/6 homozygous animals. Sequence comparison within exon 3 region also showed no differences. Results from indel sequence analysis within three regions of PRNP gene were also quite uniform between both forms of BSE. D. Therefore no genetic traits explaining the appearance of atypical BSE could be found. However, it is too early to reject the hypothesis that genetic makeup is not involved in atypical BSE. Further and more detailed studies including more cases of atypical BSE would be more reliable to draw such a conclusion.
Biological typing of sporadic Creutzfeldt- Jakob disease isolates and comparison with animal prion isolates
Romolo Nonno1, Michele Di Bari1, Laura Pirisinu1, Stefano Marcon1, Claudia D'Agostino1, Elena Esposito1, Paola Fazzi1, Shimon Simson1, Paolo Frassanito1, Cristina Casalone3, Franco Cardone2, Maurizio Pocchiari2, Gabriele Vaccari1, Umberto Agrimi1 1Dept. SPVSA, Istituto Superiore di Sanità, Italy; 2Dept. BCN, Istituto Superiore di Sanità, Italy; 3Istituto Zooprofilattico del Piemonte, Liguria e Valle D'Aosta, Italy
Background: Our incomplete understanding of the nature of TSE agents, along with the current technical limitations in the analysis of PrPSc structure, prevent the direct typing of prion isolates. The characterization of prion strains still relies upon bioassay in rodents. Bank vole (Myodes glareolus), being susceptible to a wide range of prion sources, offers the opportunity to investigate the biological properties of prion isolates from different species in a single model.
Objectives: To study the biological properties of sCJD subtypes and compare them with animal TSEs. Methods: We analysed the phenotype of transmission of MM1, MV1, MM2, MV2, and VV2 sCJD subtypes to voles, in comparison with BSE, BASE and classical scrapie isolates from different EU countries. Molecular analysis of PrPSc from the original isolates preceded voles inoculation. Survival time and attack rate were calculated upon primary transmissions and subsequent passages. The brain of voles were analysed by WB for PrPSc type, by Gnd- HCl denaturation for PrPSc conformational stability, by immunohistochemistry and PET-blot for PrPSc deposition pattern and by E&E for lesion profile.
Results: This study demonstrated that prion diseases induce in voles a variety of molecular and pathological phenotypes. CJD isolates were grouped into 4 categories: i) MM1/MV1 (n=3), ii) MM2 (n=1), iii) MV2 (n=2) and iv) VV2 (n=1). Scrapie isolates were categorised in at least 4 groups, with no overlapping with sCJD isolates. BSE was distinct from scrapie and sCJD phenotypes. Finally, BASE gave a phenotype distinct from BSE and scrapie but indistinguishable from VV2 sCJD.
Discussion: Overall, the biological classification of sCJD subtypes concurs with their clinico-pathological classification.*** Similarities in the transmission pattern of prion isolates from different host species were very rare, with the notable exception of BASE and VV2 sCJD. Herein, the meaning of such similarities is discussed in the context of current knowledge on strains and of available tools for their typing.
P26 TRANSMISSION OF ATYPICAL BOVINE SPONGIFORM ENCEPHALOPATHY (BSE) IN HUMANIZED MOUSE MODELS
Liuting Qing1, Fusong Chen1, Michael Payne1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5*, and Qingzhong Kong1 1Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA; 2CEA, Istituto Zooprofilattico Sperimentale, Italy; 3Friedrich-Loeffler-Institut, Germany; 4National Veterinary Research Institute, Poland; 5Kansas State University, Diagnostic Medicine/Pathobiology Department, Manhattan, KS 66506, USA. *Previous address: USDA National Animal Disease Center, Ames, IA 50010, USA
Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Two atypical BSE strains, BSE-L (also named BASE) and BSE-H, have been discovered in three continents since 2004. The first case of naturally occurring BSE with mutated bovine PrP gene (termed BSE-M) was also found in 2006 in the USA. The transmissibility and phenotypes of these atypical BSE strains/isolates in humans were unknown. We have inoculated humanized transgenic mice with classical and atypical BSE strains (BSE-C, BSE-L, BSE-H) and the BSE-M isolate. We have found that the atypical BSE-L strain is much more virulent than the classical BSE-C.*** The atypical BSE-H strain is also transmissible in the humanized transgenic mice with distinct phenotype, but no transmission has been observed for the BSE-M isolate so far.
III International Symposium on THE NEW PRION BIOLOGY: BASIC SCIENCE, DIAGNOSIS AND THERAPY 2 - 4 APRIL 2009, VENEZIA (ITALY)
I ask Professor Kong ;
Thursday, December 04, 2008 3:37 PM Subject: RE: re--Chronic Wating Disease (CWD) and Bovine Spongiform Encephalopathies (BSE): Public Health Risk Assessment
''IS the h-BSE more virulent than typical BSE as well, or the same as cBSE, or less virulent than cBSE? just curious.....''
Professor Kong reply ;
''As to the H-BSE, we do not have sufficient data to say one way or another, but we have found that H-BSE can infect humans. I hope we could publish these data once the study is complete. Thanks for your interest.''
Best regards, Qingzhong Kong, PhD Associate Professor Department of Pathology Case Western Reserve University Cleveland, OH 44106 USA
Tuesday, November 02, 2010
BSE - ATYPICAL LESION DISTRIBUTION (RBSE 92-21367) statutory (obex only) diagnostic criteria CVL 1992
BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein
Emmanuel A. Asante, Jacqueline M. Linehan, Melanie Desbruslais, Susan Joiner, Ian Gowland, Andrew L. Wood, Julie Welch, Andrew F. Hill, Sarah E. Lloyd, Jonathan D.F. Wadsworth, and John Collinge1 MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, Queen Square, London WC1N 3BG, UK 1Corresponding author e-mail: firstname.lastname@example.orgReceived August 1, 2002; Revised September 24, 2002; Accepted October 17, 2002.
The EMBO Journal (2002) 21, 6358 - 6366 doi:10.1093/emboj/cdf653
BSE prions propagate as either variant CJD-like or sporadic CJD-like prion strains in transgenic mice expressing human prion protein
Emmanuel A. Asante1, Jacqueline M. Linehan1, Melanie Desbruslais1, Susan Joiner1, Ian Gowland1, Andrew L. Wood1, Julie Welch1, Andrew F. Hill1, Sarah E. Lloyd1, Jonathan D.F. Wadsworth1 and John Collinge1
1.MRC Prion Unit and Department of Neurodegenerative Disease, Institute of Neurology, University College, Queen Square, London WC1N 3BG, UK Correspondence to:
John Collinge, E-mail: email@example.com
Received 1 August 2002; Accepted 17 October 2002; Revised 24 September 2002
Variant Creutzfeldt-Jakob disease (vCJD) has been recognized to date only in individuals homozygous for methionine at PRNP codon 129. Here we show that transgenic mice expressing human PrP methionine 129, inoculated with either bovine spongiform encephalopathy (BSE) or variant CJD prions, may develop the neuropathological and molecular phenotype of vCJD, consistent with these diseases being caused by the same prion strain. Surprisingly, however, BSE transmission to these transgenic mice, in addition to producing a vCJD-like phenotype, can also result in a distinct molecular phenotype that is indistinguishable from that of sporadic CJD with PrPSc type 2. These data suggest that more than one BSE-derived prion strain might infect humans; it is therefore possible that some patients with a phenotype consistent with sporadic CJD may have a disease arising from BSE exposure.
Keywords:BSE, Creutzfeldt-Jakob disease, prion, transgenic
Archive Number 20101206.4364 Published Date 06-DEC-2010 Subject PRO/AH/EDR> Prion disease update 2010 (11)
PRION DISEASE UPDATE 2010 (11)
TAFS1 Position Paper on Position Paper on Relaxation of the Feed Ban in the EU Berne, 2010 TAFS
INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation
10,000,000+ LBS. of PROHIBITED BANNED MAD COW FEED I.E. BLOOD LACED MBM IN COMMERCE USA 2007
Date: March 21, 2007 at 2:27 pm PST
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINES -- CLASS II
Bulk cattle feed made with recalled Darling's 85% Blood Meal, Flash Dried, Recall # V-024-2007
Cattle feed delivered between 01/12/2007 and 01/26/2007
Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007.
Firm initiated recall is ongoing.
Blood meal used to make cattle feed was recalled because it was cross- contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
Custom dairy premix products: MNM ALL PURPOSE Pellet, HILLSIDE/CDL Prot- Buffer Meal, LEE, M.-CLOSE UP PX Pellet, HIGH DESERT/ GHC LACT Meal, TATARKA, M CUST PROT Meal, SUNRIDGE/CDL PROTEIN Blend, LOURENZO, K PVM DAIRY Meal, DOUBLE B DAIRY/GHC LAC Mineral, WEST PIONT/GHC CLOSEUP Mineral, WEST POINT/GHC LACT Meal, JENKS, J/COMPASS PROTEIN Meal, COPPINI - 8# SPECIAL DAIRY Mix, GULICK, L-LACT Meal (Bulk), TRIPLE J - PROTEIN/LACTATION, ROCK CREEK/GHC MILK Mineral, BETTENCOURT/GHC S.SIDE MK-MN, BETTENCOURT #1/GHC MILK MINR, V&C DAIRY/GHC LACT Meal, VEENSTRA, F/GHC LACT Meal, SMUTNY, A- BYPASS ML W/SMARTA, Recall # V-025-2007
The firm does not utilize a code - only shipping documentation with commodity and weights identified.
Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007. Firm initiated recall is complete.
Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE
ID and NV
END OF ENFORCEMENT REPORT FOR MARCH 21, 2007
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. *It also suggests a similar cause or source for atypical BSE in these countries.
Saturday, November 6, 2010
TAFS1 Position Paper on Position Paper on Relaxation of the Feed Ban in the EU Berne, 2010 TAFS
INTERNATIONAL FORUM FOR TRANSMISSIBLE ANIMAL DISEASES AND FOOD SAFETY a non-profit Swiss Foundation
Saturday, August 14, 2010
BSE Case Associated with Prion Protein Gene Mutation (g-h-BSEalabama) and VPSPr PRIONPATHY
(see mad cow feed in COMMERCE IN ALABAMA...TSS)
Sunday, March 27, 2011
SCRAPIE USA UPDATE FEBRUARY 2011
and why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man. I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough. Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
Monday, April 25, 2011
Experimental Oral Transmission of Atypical Scrapie to Sheep
Volume 17, Number 5–May 2011
Atypical/Nor98 Scrapie Infectivity in Sheep Peripheral Tissues
Olivier Andréoletti1*, Leonor Orge2, Sylvie L. Benestad3, Vincent Beringue4, Claire Litaise1, Stéphanie Simon5, Annick Le Dur4, Hubert Laude4, Hugh Simmons6, Séverine Lugan1, Fabien Corbière1, Pierrette Costes1, Nathalie Morel5, François Schelcher1, Caroline Lacroux1
1 UMR INRA ENVT 1225, Interactions Hôtes Agents Pathogènes, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France, 2 Laboratório Nacional de Investigação Veterinária, Lisboa, Portugal, 3 National Veterinary Institute, Oslo, Norway, 4 INRA UR892, Virologie et Immunologie Moléculaires, INRA, F-78350 Jouy-en-Josas, France, 5 CEA, Service de Pharmacologie et d'Immunoanalyse, IBiTec-S, DSV, CEA/Saclay, Gif sur Yvette cedex, France, 6 VLA Weybridge, ASU, Addlestone, Surrey, United Kingdom
Atypical/Nor98 scrapie was first identified in 1998 in Norway. It is now considered as a worldwide disease of small ruminants and currently represents a significant part of the detected transmissible spongiform encephalopathies (TSE) cases in Europe. Atypical/Nor98 scrapie cases were reported in ARR/ARR sheep, which are highly resistant to BSE and other small ruminants TSE agents. The biology and pathogenesis of the Atypical/Nor98 scrapie agent in its natural host is still poorly understood. However, based on the absence of detectable abnormal PrP in peripheral tissues of affected individuals, human and animal exposure risk to this specific TSE agent has been considered low. In this study we demonstrate that infectivity can accumulate, even if no abnormal PrP is detectable, in lymphoid tissues, nerves, and muscles from natural and/or experimental Atypical/Nor98 scrapie cases. Evidence is provided that, in comparison to other TSE agents, samples containing Atypical/Nor98 scrapie infectivity could remain PrPSc negative. This feature will impact detection of Atypical/Nor98 scrapie cases in the field, and highlights the need to review current evaluations of the disease prevalence and potential transmissibility. Finally, an estimate is made of the infectivity loads accumulating in peripheral tissues in both Atypical/Nor98 and classical scrapie cases that currently enter the food chain. The results obtained indicate that dietary exposure risk to small ruminants TSE agents may be higher than commonly believed.
Increased Atypical Scrapie Detections
Press reports indicate that increased surveillance is catching what otherwise would have been unreported findings of atypical scrapie in sheep. In 2009, five new cases have been reported in Quebec, Ontario, Alberta, and Saskatchewan. With the exception of Quebec, all cases have been diagnosed as being the atypical form found in older animals. Canada encourages producers to join its voluntary surveillance program in order to gain scrapie-free status. The World Animal Health will not classify Canada as scrapie-free until no new cases are reported for seven years. The Canadian Sheep Federation is calling on the government to fund a wider surveillance program in order to establish the level of prevalence prior to setting an eradication date. Besides long-term testing, industry is calling for a compensation program for farmers who report unusual deaths in their flocks.
PUTTING THE CART BEFORE THE HORSE, in terms of human health risk $$$
Monday, November 30, 2009
USDA AND OIE COLLABORATE TO EXCLUDE ATYPICAL SCRAPIE NOR-98 ANIMAL HEALTH CODE
Wednesday, February 16, 2011
SCRAPIE TRANSMISSION TO CHIMPANZEES
Monday, March 21, 2011
Sheep and Goat BSE Propagate More Efficiently than Cattle BSE in Human PrP Transgenic Mice
On the other hand, this component would not be distinguishable from bovine-passaged BSE prions due to the current limits of the standard biological methods and/or the molecular tools employed here to characterize prion strains. Whatever the mechanism, the notion that a passage through an intermediate species can profoundly alter prion virulence for the human species has important public-health issues, regarding emerging and/or expanding TSEs, like atypical scrapie or CWD.
Taken all together, our results suggest that the possibility of a small ruminant BSE prion as vCJD causal agent could not be ruled out, which has important implications on public and animal health policies. On one hand, although the exact magnitude and characteristic of the vCJD epidemic is still unclear, its link with cattle BSE is supported by strong epidemiological ground and several experimental data. On the other hand, the molecular typing performed in our studies, indicates that the biochemical characteristics of the PrPres detected in brains of our sheep and goat BSE-inoculated mice seem to be indistinguishable from that observed in vCJD. Considering the similarity in clinical manifestation of BSE- and scrapie-affected sheep , a masker effect of scrapie over BSE, as well as a potential adaptation of the BSE agent through subsequent passages, could not be ruled out. As BSE infected sheep PrPSc have been detected in many peripheral organs, small ruminant-passaged BSE prions might be a more widespread source of BSE infectivity compared to cattle , , . This fact is even more worrying since our transmission studies suggest that apparently Met129 human PrP favours a BSE agent with ovine rather than a bovine sequence. Finally, it is evident that, although few natural cases have been described and so far we cannot draw any definitive conclusion about the origin of vCJD, we can not underestimate the risk of a potential goat and/or sheep BSE agent.
Prion strains may vary in their ability to transmit to humans and animals. Few experimental studies have been done to provide evidence of differences between U.S. strains of scrapie, which can be distinguished by incubation times in inbred mice, microscopic lesions, immunoreactivity to various antibodies, or molecular profile (electrophoretic mobility and glycoform ratio). Recent work on two U.S. isolates of sheep scrapie supports that at least two distinct strains exist based on differences in incubation time and genotype of sheep affected. One isolate (No. 13-7) inoculated intracerebrally caused scrapie in sheep AA at codon 136 (AA136) and QQ at codon 171 (QQ171) of the prion protein in an average of 19 months post-inoculation (PI) whereas a second isolate (No. x124) caused disease in less than 12 months after oral inoculation in AV136/QQ171 sheep. Striking differences were evident when further strain analysis was done in R111, VM, C57Bl6, and C57Bl6xVM (F1) mice. No. 13-7 did not induce disease in any mouse strain at any time post-inoculation (PI) nor were brain tissues positive by western blot (WB). Positive WB results were obtained from mice inoculated with isolate No. x124 starting at day 380 PI. Incubation times averaged 508, 559, 601, and 633 days PI for RIII, C57Bl6, VM, and F1 mice, respectively. Further passage will be required to characterize these scrapie strains in mice. This work provides evidence that multiple scrapie strains exist in U.S. sheep.
One of these isolates (TR316211) behaved like the CH1641 isolate, with PrPres features in mice similar to those in the sheep brain. From two other isolates (O100 and O104), two distinct PrPres phenotypes were identified in mouse brains, with either high (h-type) or low (l-type) apparent molecular masses of unglycosylated PrPres, the latter being similar to that observed with CH1641, TR316211, or BSE. Both phenotypes could be found in variable proportions in the brains of the individual mice. In contrast with BSE, l-type PrPres from "CH1641-like" isolates showed lower levels of diglycosylated PrPres. From one of these cases (O104), a second passage in mice was performed for two mice with distinct PrPres profiles. This showed a partial selection of the l-type phenotype in mice infected with a mouse brain with predominant l-type PrPres, and it was accompanied by a significant increase in the proportions of the diglycosylated band. These results are discussed in relation to the diversity of scrapie and BSE strains.
In the US, scrapie is reported primarily in sheep homozygous for 136A/171Q (AAQQ) and the disease phenotype is similar to that seen with experimental strain CH1641.
Background ----------- "Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. [Many of the neurological diseases can be transmitted by intracerebral inoculation, which causes this moderator to approach intracerebral studies as a tool for study, but not necessarily as a direct indication of transmissibility of natural diseases. - Mod.TG]
"The 1st successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.
"Results -------- "This study demonstrates that atypical scrapie has distinct clinical, pathological, and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.
"Conclusions ------------ Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage."
Lastly, this moderator wishes to thank Terry Singletary for some of his behind the scenes work of providing citations and references for this posting. - Mod.TG]
The HealthMap/ProMED-mail interactive map of Australia is available at
The two Commissions discussed the issue of 'atypical' scrapie in terms of notification requirements and the issue of the host genetic resistance. In response to questions of Members, the Code Commission clarified that 'classical' scrapie is reportable to the OIE but that 'atypical' scrapie is not reportable (in accordance with the recommendations made by the ad hoc Group on Atypical Scrapie and Atypical BSE, which met in November 2007). However, the sharing of scientific information on 'atypical' scrapie is encouraged. At this time, the Code Commission considered that more scientific information would be needed to fully address the issues associated with host genotype.
OIE Terrestrial Animal Health Standards Commission / September 2010
The EU takes note of the fact that atypical scrapie is not an OIE listed disease. Nevertheless, it will remain notifiable in the EU. Moreover it must be stressed that any emergence of this disease should be notified to the OIE by Members and that scientific data should continue to be gathered.
Has transmission to humans been proven? (with the exception of artificial
Is human infection associated with severe consequences? (death or prolonged illness)
Sunday, December 12, 2010
EFSA reviews BSE/TSE infectivity in small ruminant tissues News Story 2 December 2010
Monday, November 22, 2010
Atypical transmissible spongiform encephalopathies in ruminants: a challenge for disease surveillance and control
Sunday, April 18, 2010
SCRAPIE AND ATYPICAL SCRAPIE TRANSMISSION STUDIES A REVIEW 2010
Wednesday, January 19, 2011
EFSA and ECDC review scientific evidence on possible links between TSEs in animals and humans Webnachricht 19 Januar 2011
Tuesday, January 18, 2011
Agent strain variation in human prion disease: insights from a molecular and pathological review of the National Institutes of Health series of experimentally transmitted disease
EVIDENCE OF SCRAPIE IN SHEEP AS A RESULT OF FOOD BORNE EXPOSURE
This is provided by the statistically significant increase in the incidence of sheep scrape from 1985, as determined from analyses of the submissions made to VI Centres, and from individual case and flock incident studies. ........
RISK OF BSE TO SHEEP VIA FEED
Marion Simmons communicated surprising evidence for oral transmissibility of Nor98/atypical scrapie in neonatal sheep and although bioassay is ongoing, infectivity of the distal ileum of 12 and 24 month infected sheep is positive in Tg338 mice.
SUMMARY REPORTS OF MAFF BSE TRANSMISSION STUDIES AT THE CVL ;
THE RISK TO HUMANS FROM SHEEP;
EXPERIMENTAL TRANSMISSION OF BSE TO SHEEP
SHEEP AND BSE
PERSONAL AND CONFIDENTIAL
SHEEP AND BSE
A. The experimental transmission of BSE to sheep.
Studies have shown that the ''negative'' line NPU flock of Cheviots can be experimentally infected with BSE by intracerebral (ic) or oral challenge (the latter being equivalent to 0.5 gram of a pool of four cow brains from animals confirmed to have BSE).
BSE - TRANSMISSION STUDIES
1: J Infect Dis 1980 Aug;142(2):205-8
Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates.
Gibbs CJ Jr, Amyx HL, Bacote A, Masters CL, Gajdusek DC.
Kuru and Creutzfeldt-Jakob disease of humans and scrapie disease of sheep and goats were transmitted to squirrel monkeys (Saimiri sciureus) that were exposed to the infectious agents only by their nonforced consumption of known infectious tissues. The asymptomatic incubation period in the one monkey exposed to the virus of kuru was 36 months; that in the two monkeys exposed to the virus of Creutzfeldt-Jakob disease was 23 and 27 months, respectively; and that in the two monkeys exposed to the virus of scrapie was 25 and 32 months, respectively. Careful physical examination of the buccal cavities of all of the monkeys failed to reveal signs or oral lesions. One additional monkey similarly exposed to kuru has remained asymptomatic during the 39 months that it has been under observation.
The successful transmission of kuru, Creutzfeldt-Jakob disease, and scrapie by natural feeding to squirrel monkeys that we have reported provides further grounds for concern that scrapie-infected meat may occasionally give rise in humans to Creutzfeldt-Jakob disease.
12/10/76 AGRICULTURAL RESEARCH COUNCIL REPORT OF THE ADVISORY COMMITTE ON SCRAPIE Office Note CHAIRMAN: PROFESSOR PETER WILDY
A The Present Position with respect to Scrapie A] The Problem Scrapie is a natural disease of sheep and goats. It is a slow and inexorably progressive degenerative disorder of the nervous system and it ia fatal. It is enzootic in the United Kingdom but not in all countries. The field problem has been reviewed by a MAFF working group (ARC 35/77). It is difficult to assess the incidence in Britain for a variety of reasons but the disease causes serious financial loss; it is estimated that it cost Swaledale breeders alone $l.7 M during the five years 1971-1975. A further inestimable loss arises from the closure of certain export markets, in particular those of the United States, to British sheep. It is clear that scrapie in sheep is important commercially and for that reason alone effective measures to control it should be devised as quickly as possible. Recently the question has again been brought up as to whether scrapie is transmissible to man. This has followed reports that the disease has been transmitted to primates.
One particularly lurid speculation (Gajdusek 1977) conjectures that the agents of scrapie, kuru, Creutzfeldt-Jakob disease and transmissible encephalopathy of mink are varieties of a single "virus". The U.S. Department of Agriculture concluded that it could "no longer justify or permit scrapie-blood line and scrapie-exposed sheep and goats to be processed for human or animal food at slaughter or rendering plants" (ARC 84/77)" The problem is emphasised by the finding that some strains of scrapie produce lesions identical to the once which characterise the human dementias" Whether true or not. the hypothesis that these agents might be transmissible to man raises two considerations. First, the safety of laboratory personnel requires prompt attention. Second, action such as the "scorched meat" policy of USDA makes the solution of the acrapie problem urgent if the sheep industry is not to suffer grievously.
Nature. 1972 Mar 10;236(5341):73-4.
Transmission of scrapie to the cynomolgus monkey (Macaca fascicularis).
Gibbs CJ Jr, Gajdusek DC. Nature 236, 73 - 74 (10 March 1972); doi:10.1038/236073a0
Transmission of Scrapie to the Cynomolgus Monkey (Macaca fascicularis)
C. J. GIBBS jun. & D. C. GAJDUSEK National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
SCRAPIE has been transmitted to the cynomolgus, or crab-eating, monkey (Macaca fascicularis) with an incubation period of more than 5 yr from the time of intracerebral inoculation of scrapie-infected mouse brain. The animal developed a chronic central nervous system degeneration, with ataxia, tremor and myoclonus with associated severe scrapie-like pathology of intensive astroglial hypertrophy and proliferation, neuronal vacuolation and status spongiosus of grey matter. The strain of scrapie virus used was the eighth passage in Swiss mice (NIH) of a Compton strain of scrapie obtained as ninth intracerebral passage of the agent in goat brain, from Dr R. L. Chandler (ARC, Compton, Berkshire).
Epidemiology of Scrapie in the United States 1977
Aspects of the Cerebellar Neuropathology in Nor98
Gavier-Widén, D1; Benestad, SL2; Ottander, L1; Westergren, E1 1National Veterinary Insitute, Sweden; 2National Veterinary Institute,
Norway Nor98 is a prion disease of old sheep and goats. This atypical form of scrapie was first described in Norway in 1998. Several features of Nor98 were shown to be different from classical scrapie including the distribution of disease associated prion protein (PrPd) accumulation in the brain. The cerebellum is generally the most affected brain area in Nor98. The study here presented aimed at adding information on the neuropathology in the cerebellum of Nor98 naturally affected sheep of various genotypes in Sweden and Norway. A panel of histochemical and immunohistochemical (IHC) stainings such as IHC for PrPd, synaptophysin, glial fibrillary acidic protein, amyloid, and cell markers for phagocytic cells were conducted. The type of histological lesions and tissue reactions were evaluated. The types of PrPd deposition were characterized. The cerebellar cortex was regularly affected, even though there was a variation in the severity of the lesions from case to case. Neuropil vacuolation was more marked in the molecular layer, but affected also the granular cell layer. There was a loss of granule cells. Punctate deposition of PrPd was characteristic. It was morphologically and in distribution identical with that of synaptophysin, suggesting that PrPd accumulates in the synaptic structures. PrPd was also observed in the granule cell layer and in the white matter. The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
***The pathology features of Nor98 in the cerebellum of the affected sheep showed similarities with those of sporadic Creutzfeldt-Jakob disease in humans.
NOR98 SHOWS MOLECULAR FEATURES REMINISCENT OF GSS
R. Nonno1, E. Esposito1, G. Vaccari1, E. Bandino2, M. Conte1, B. Chiappini1, S. Marcon1, M. Di Bari1, S.L. Benestad3, U. Agrimi1 1 Istituto Superiore di Sanità, Department of Food Safety and Veterinary Public Health, Rome, Italy (firstname.lastname@example.org); 2 Istituto Zooprofilattico della Sardegna, Sassari, Italy; 3 National Veterinary Institute, Department of Pathology, Oslo, Norway
Molecular variants of PrPSc are being increasingly investigated in sheep scrapie and are generally referred to as "atypical" scrapie, as opposed to "classical scrapie". Among the atypical group, Nor98 seems to be the best identified. We studied the molecular properties of Italian and Norwegian Nor98 samples by WB analysis of brain homogenates, either untreated, digested with different concentrations of proteinase K, or subjected to enzymatic deglycosylation. The identity of PrP fragments was inferred by means of antibodies spanning the full PrP sequence. We found that undigested brain homogenates contain a Nor98-specific PrP fragment migrating at 11 kDa (PrP11), truncated at both the C-terminus and the N-terminus, and not N-glycosylated. After mild PK digestion, Nor98 displayed full-length PrP (FL-PrP) and N-glycosylated C-terminal fragments (CTF), along with increased levels of PrP11. Proteinase K digestion curves (0,006-6,4 mg/ml) showed that FL-PrP and CTF are mainly digested above 0,01 mg/ml, while PrP11 is not entirely digested even at the highest concentrations, similarly to PrP27-30 associated with classical scrapie. Above 0,2 mg/ml PK, most Nor98 samples showed only PrP11 and a fragment of 17 kDa with the same properties of PrP11, that was tentatively identified as a dimer of PrP11. Detergent solubility studies showed that PrP11 is insoluble in 2% sodium laurylsorcosine and is mainly produced from detergentsoluble, full-length PrPSc. Furthermore, among Italian scrapie isolates, we found that a sample with molecular and pathological properties consistent with Nor98 showed plaque-like deposits of PrPSc in the thalamus when the brain was analysed by PrPSc immunohistochemistry. Taken together, our results show that the distinctive pathological feature of Nor98 is a PrP fragment spanning amino acids ~ 90-155. This fragment is produced by successive N-terminal and C-terminal cleavages from a full-length and largely detergent-soluble PrPSc, is produced in vivo and is extremely resistant to PK digestion.
*** Intriguingly, these conclusions suggest that some pathological features of Nor98 are reminiscent of Gerstmann-Sträussler-Scheinker disease.
A newly identified type of scrapie agent can naturally infect sheep with resistant PrP genotypes
Annick Le Dur*,?, Vincent Béringue*,?, Olivier Andréoletti?, Fabienne Reine*, Thanh Lan Laï*, Thierry Baron§, Bjørn Bratberg¶, Jean-Luc Vilotte?, Pierre Sarradin**, Sylvie L. Benestad¶, and Hubert Laude*,? +Author Affiliations
*Virologie Immunologie Moléculaires and ?Génétique Biochimique et Cytogénétique, Institut National de la Recherche Agronomique, 78350 Jouy-en-Josas, France; ?Unité Mixte de Recherche, Institut National de la Recherche Agronomique-Ecole Nationale Vétérinaire de Toulouse, Interactions Hôte Agent Pathogène, 31066 Toulouse, France; §Agence Française de Sécurité Sanitaire des Aliments, Unité Agents Transmissibles Non Conventionnels, 69364 Lyon, France; **Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, 37380 Nouzilly, France; and ¶Department of Pathology, National Veterinary Institute, 0033 Oslo, Norway
***Edited by Stanley B. Prusiner, University of California, San Francisco, CA (received for review March 21, 2005)
Abstract Scrapie in small ruminants belongs to transmissible spongiform encephalopathies (TSEs), or prion diseases, a family of fatal neurodegenerative disorders that affect humans and animals and can transmit within and between species by ingestion or inoculation. Conversion of the host-encoded prion protein (PrP), normal cellular PrP (PrPc), into a misfolded form, abnormal PrP (PrPSc), plays a key role in TSE transmission and pathogenesis. The intensified surveillance of scrapie in the European Union, together with the improvement of PrPSc detection techniques, has led to the discovery of a growing number of so-called atypical scrapie cases. These include clinical Nor98 cases first identified in Norwegian sheep on the basis of unusual pathological and PrPSc molecular features and "cases" that produced discordant responses in the rapid tests currently applied to the large-scale random screening of slaughtered or fallen animals. Worryingly, a substantial proportion of such cases involved sheep with PrP genotypes known until now to confer natural resistance to conventional scrapie. Here we report that both Nor98 and discordant cases, including three sheep homozygous for the resistant PrPARR allele (A136R154R171), efficiently transmitted the disease to transgenic mice expressing ovine PrP, and that they shared unique biological and biochemical features upon propagation in mice. *** These observations support the view that a truly infectious TSE agent, unrecognized until recently, infects sheep and goat flocks and may have important implications in terms of scrapie control and public health.
Monday, December 1, 2008
When Atypical Scrapie cross species barriers
Andreoletti O., Herva M. H., Cassard H., Espinosa J. C., Lacroux C., Simon S., Padilla D., Benestad S. L., Lantier F., Schelcher F., Grassi J., Torres, J. M., UMR INRA ENVT 1225, Ecole Nationale Veterinaire de Toulouse.France; ICISA-INlA, Madrid, Spain; CEA, IBiTec-5, DSV, CEA/Saclay, Gif sur Yvette cedex, France; National Veterinary Institute, Postboks 750 Sentrum, 0106 Oslo, Norway, INRA IASP, Centre INRA de Tours, 3738O Nouzilly, France.
Atypical scrapie is a TSE occurring in small ruminants and harbouring peculiar clinical, epidemiological and biochemical properties. Currently this form of disease is identified in a large number of countries. In this study we report the transmission of an atypical scrapie isolate through different species barriers as modeled by transgenic mice (Tg) expressing different species PRP sequence.
The donor isolate was collected in 1995 in a French commercial sheep flock. inoculation into AHQ/AHQ sheep induced a disease which had all neuro-pathological and biochemical characteristics of atypical scrapie. Transmitted into Transgenic mice expressing either ovine or PrPc, the isolate retained all the described characteristics of atypical scrapie.
Surprisingly the TSE agent characteristics were dramatically different v/hen passaged into Tg bovine mice. The recovered TSE agent had biological and biochemical characteristics similar to those of atypical BSE L in the same mouse model. Moreover, whereas no other TSE agent than BSE were shown to transmit into Tg porcine mice, atypical scrapie was able to develop into this model, albeit with low attack rate on first passage.
Furthermore, after adaptation in the porcine mouse model this prion showed similar biological and biochemical characteristics than BSE adapted to this porcine mouse model. Altogether these data indicate.
(i) the unsuspected potential abilities of atypical scrapie to cross species barriers
(ii) the possible capacity of this agent to acquire new characteristics when crossing species barrier
These findings raise some interrogation on the concept of TSE strain and on the origin of the diversity of the TSE agents and could have consequences on field TSE control measures.
BSE: TIME TO TAKE H.B. PARRY SERIOUSLY
If the scrapie agent is generated from ovine DNA and thence causes disease in other species, then perhaps, bearing in mind the possible role of scrapie in CJD of humans (Davinpour et al, 1985), scrapie and not BSE should be the notifiable disease. ...
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
28 Mar 01
Like lambs to the slaughter 31 March 2001 by Debora MacKenzie Magazine issue 2284. Subscribe and get 4 free issues. FOUR years ago, Terry Singeltary watched his mother die horribly from a degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary was suspicious. The diagnosis didn't fit her violent symptoms, and he demanded an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.
Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise. He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals. Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.
Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears. To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.
"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris. Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb.
Scrapie has been around for centuries and until now there has been no evidence that it poses a risk to human health. But if the French finding means that scrapie can cause sCJD in people, countries around the world may have overlooked a CJD crisis to rival that caused by BSE.
Deslys and colleagues were originally studying vCJD, not sCJD. They injected the brains of macaque monkeys with brain from BSE cattle, and from French and British vCJD patients. The brain damage and clinical symptoms in the monkeys were the same for all three. Mice injected with the original sets of brain tissue or with infected monkey brain also developed the same symptoms.
As a control experiment, the team also injected mice with brain tissue from people and animals with other prion diseases: a French case of sCJD; a French patient who caught sCJD from human-derived growth hormone; sheep with a French strain of scrapie; and mice carrying a prion derived from an American scrapie strain. As expected, they all affected the brain in a different way from BSE and vCJD. But while the American strain of scrapie caused different damage from sCJD, the French strain produced exactly the same pathology.
"The main evidence that scrapie does not affect humans has been epidemiology," says Moira Bruce of the neuropathogenesis unit of the Institute for Animal Health in Edinburgh, who was a member of the same team as Deslys. "You see about the same incidence of the disease everywhere, whether or not there are many sheep, and in countries such as New Zealand with no scrapie." In the only previous comparisons of sCJD and scrapie in mice, Bruce found they were dissimilar.
But there are more than 20 strains of scrapie, and six of sCJD. "You would not necessarily see a relationship between the two with epidemiology if only some strains affect only some people," says Deslys. Bruce is cautious about the mouse results, but agrees they require further investigation. Other trials of scrapie and sCJD in mice, she says, are in progress.
People can have three different genetic variations of the human prion protein, and each type of protein can fold up two different ways. Kretschmar has found that these six combinations correspond to six clinical types of sCJD: each type of normal prion produces a particular pathology when it spontaneously deforms to produce sCJD.
But if these proteins deform because of infection with a disease-causing prion, the relationship between pathology and prion type should be different, as it is in vCJD. "If we look at brain samples from sporadic CJD cases and find some that do not fit the pattern," says Kretschmar, "that could mean they were caused by infection."
There are 250 deaths per year from sCJD in the US, and a similar incidence elsewhere. Singeltary and other US activists think that some of these people died after eating contaminated meat or "nutritional" pills containing dried animal brain. Governments will have a hard time facing activists like Singeltary if it turns out that some sCJD isn't as spontaneous as doctors have insisted.
Deslys's work on macaques also provides further proof that the human disease vCJD is caused by BSE. And the experiments showed that vCJD is much more virulent to primates than BSE, even when injected into the bloodstream rather than the brain. This, says Deslys, means that there is an even bigger risk than we thought that vCJD can be passed from one patient to another through contaminated blood transfusions and surgical instruments.
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
(hmmm, this is getting interesting now...TSS)
Sporadic CJD type 1 and atypical/ Nor98 scrapie are characterized by fine (reticular) deposits,
see also ;
All of the Heidenhain variants were of the methionine/ methionine type 1 molecular subtype.
see full text ;
Monday, December 14, 2009
Similarities between Forms of Sheep Scrapie and Creutzfeldt-Jakob Disease Are Encoded by Distinct Prion Types
Tuesday, April 28, 2009
Nor98-like Scrapie in the United States of America
Wednesday, March 3, 2010
NOR-98 ATYPICAL SCRAPIE USA 4 CASES DETECTED JANUARY 2010
Prions in Skeletal Muscles of Deer with Chronic Wasting Disease
Rachel C. Angers1,*, Shawn R. Browning1,*?, Tanya S. Seward2, Christina J. Sigurdson4,?, Michael W. Miller5, Edward A. Hoover4 and Glenn C. Telling1,2,3,§ + Author Affiliations
The emergence of chronic wasting disease (CWD) in deer and elk in an increasingly wide geographic area, as well as the interspecies transmission of bovine spongiform encephalopathy to humans in the form of variant Creutzfeldt Jakob disease, have raised concerns about the zoonotic potential of CWD. Because meat consumption is the most likely means of exposure, it is important to determine whether skeletal muscle of diseased cervids contains prion infectivity. Here bioassays in transgenic mice expressing cervid prion protein revealed the presence of infectious prions in skeletal muscles of CWD-infected deer, demonstrating that humans consuming or handling meat from CWD-infected deer are at risk to prion exposure.
Received for publication 21 November 2005. Accepted for publication 13 January 2006.
Journal of Virology, September 2009, p. 9608-9610, Vol. 83, No. 18 0022-538X/09/$08.00+0 doi:10.1128/JVI.01127-09 Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Prion Infectivity in Fat of Deer with Chronic Wasting Disease
Brent Race,# Kimberly Meade-White,# Richard Race, and Bruce Chesebro* Rocky Mountain Laboratories, 903 South 4th Street, Hamilton, Montana 59840
Received 2 June 2009/ Accepted 24 June 2009
ABSTRACT Top ABSTRACT TEXT REFERENCES
Chronic wasting disease (CWD) is a neurodegenerative prion disease of cervids. Some animal prion diseases, such as bovine spongiform encephalopathy, can infect humans; however, human susceptibility to CWD is unknown. In ruminants, prion infectivity is found in central nervous system and lymphoid tissues, with smaller amounts in intestine and muscle. In mice, prion infectivity was recently detected in fat. Since ruminant fat is consumed by humans and fed to animals, we determined infectivity titers in fat from two CWD-infected deer. Deer fat devoid of muscle contained low levels of CWD infectivity and might be a risk factor for prion infection of other species.
The highest risk of human contact with CWD might be through exposure to high-titer CNS tissue through accidental skin cuts or corneal contact at the time of harvest and butchering. However, the likelihood of a human consuming fat infected with a low titer of the CWD agent is much higher. It is impossible to remove all the fat present within muscle tissue, and fat consumption is inevitable when eating meat. Of additional concern is the fact that meat from an individual deer harvested by a hunter is typically consumed over multiple meals by the same group of people. These individuals would thus have multiple exposures to the CWD agent over time, which might increase the chance for transfer of infection.
In the Rocky Mountain region of North America, wild deer are subject to predation by wolves, coyotes, bears, and mountain lions. Although canines such as wolves and coyotes are not known to be susceptible to prion diseases, felines definitely are susceptible to BSE (9) and might also be infected by the CWD agent. Deer infected with the CWD agent are more likely to be killed by predators such as mountain lions (11). Peripheral tissues, including lymph nodes, muscle, and fat, which harbor prion infectivity are more accessible for consumption than CNS tissue, which has the highest level of infectivity late in disease. Therefore, infectivity in these peripheral tissues may be important in potential cross-species CWD transmissions in the wild.
The present finding of CWD infectivity in deer fat tissue raises the possibility that prion infectivity might also be found in fat tissue of other infected ruminants, such as sheep and cattle, whose fat and muscle tissues are more widely distributed in both the human and domestic-animal food chains. Although the infectivity in fat tissues is low compared to that in the CNS, there may be significant differences among species and between prion strains. Two fat samples from BSE agent-infected cattle were reported to be negative by bioassay in nontransgenic RIII mice (3, 6). However, RIII mice are 10,000-fold-less sensitive to BSE agent infection than transgenic mice expressing bovine PrP (4). It would be prudent to carry out additional infectivity assays on fat from BSE agent-infected cattle and scrapie agent-infected sheep using appropriate transgenic mice or homologous species to determine the risk from these sources.
THE LATEST DATA ON TISSUE INFECTIVITY
WHO Tables on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies Updated 2010
MAJOR CATEGORIES OF INFECTIVITY: TABLES IA, IB, IC
The assignment of tissues to high, low, and undetected infectivity categories is based exclusively upon observations of naturally occurring disease, or primary experimental infection by the oral route (in ruminants). The Tables do not include results from disease models using strains of TSE that have been adapted to experimental animals, because passaged strain phenotypes can differ significantly and unpredictably from those of naturally occurring disease. However, for tissues and fluids of exceptional public health interest, such as muscle, intestine, skin, secretions and excretions, experimental results have been indicated in footnotes.
Because the detection of misfolded prion protein (PrPTSE) broadly parallels infectivity titers in various tissues [Beekes et al 1996; Andreoletti et al 2004], PrPTSE testing results are presented in parallel with bioassay data.
Although a given tissue may be positive or negative in different varieties of TSE, the expert group considered a tissue to be potentially infectious even if a positive result occurred in only a single disease. The categorical assignment of tissues will almost certainly undergo further revision as new data accumulate from increasingly sensitive tests.
IA: High-infectivity tissues: CNS tissues that attain a high titer of infectivity in the later stages of all TSEs, and certain tissues that are anatomically associated with the CNS.
IB: Lower-infectivity tissues: peripheral tissues that have tested positive for infectivity and/or PrPTSE in at least one form of TSE.
IC: Tissues with no detectable infectivity: tissues that have been examined for infectivity and/or PrPTSE with negative results.
Data entries are shown as follows:
+ Presence of infectivity or PrPTSE
- Absence of detectable infectivity or PrPTSE
NT Not tested
NA Not applicable ?
( ) Limited or preliminary data
[ ] Infectivity or PrPTSE data based exclusively on bioassays in transgenic
(Tg)mice over-expressing the PrP-encoding gene or PrPTSE amplification methods.
A word of caution is offered about tissues in Table IB for which positive results are so far limited to either detection of PrPTSE using amplification techniques (PMCA), or infectivity bioassays in Tg mice that over-express PrP. The amounts of pathological protein or infectious agent detected by these exquisitely sensitive assays may well fall below the threshold of transmissibility for normal animals and humans. WHO Tables on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies 5
A good example is illustrated in the studies of urine and feces from deer infected with CWD: bioassays using normal deer as recipient subjects were negative; subsequent bioassays performed in Tg mice were positive. A similar discordance was observed for BSE muscle inoculated into cattle and Tgmice. Until more evidence is compiled showing that positive results in experimental PMCA and Tg mouse assays equate to a risk of transmitting disease under natural conditions, it cannot be assumed that such results imply the existence of a substantial risk to the health of animals or humans.
Considering the succession of updated Tables of the past few years, and the fact that inflammation has been shown to result in PrPTSE deposition in tissues that are not normally involved in TSE pathogenesis, it is evident that as testing continues, more tissues will find their way from Table IC into Table IB (but probably not from either Table IC or IB into Table IA). It is also evident that the data generated to date are far from complete, and that a great deal more work needs to be done if conclusions about the tissue distribution and significance of infectivity in a given TSE are to be based on direct measurements rather than by analogy to other forms of the disease.
Finally, it is critically important to understand that categories of infectivity are not the same as categories of risk, which require consideration not only of the level of infectivity in tissue, but also of the amount of tissue to which a person or animal is exposed, and the route by which infection is transmitted. For example, although the level of tissue infectivity is the most important factor in estimating the risk of transmission by instrument crosscontamination during surgical procedures (e.g., neurosurgery versus general surgery), it will be only one determinant of the risk of transmission by blood transfusions, in which a large amount of low-infectivity blood is administered intravenously, or the risk of transmission by foodstuffs that, irrespective of high or low infectivity, involve a comparatively inefficient oral route of infection.
Table IC: Tissues with no detected infectivity or PrPTSE
Bone NT - NT - - NT NT NT NT NT
Tendon NT - NT - - NT NT NT NT NT
please see full text with tables here ;
WHO Tables on Tissue Infectivity Distribution in Transmissible Spongiform Encephalopathies Updated 2010
also in the references at bottom i saw ;
12. A single positive marrow in multiple transmission attempts from cattle orally dosed with BSE-infected brain [Wells et al., 1999; Wells et al., 2005; Sohn et al., 2009].
The most recent assessments (and reassessments) were published in June 2005 (Table I; 18), and included the categorisation of Canada, the USA, and Mexico as GBR III. Although only Canada and the USA have reported cases, the historically open system of trade in North America suggests that it is likely that BSE is present also in Mexico.
Saturday, March 5, 2011
MAD COW ATYPICAL CJD PRION TSE CASES WITH CLASSIFICATIONS PENDING ON THE RISE IN NORTH AMERICA
Saturday, April 30, 2011
Blood product, collected from a donor who was at risk for variant Creutzfeldt-Jakob disease (vCJD), was distributed APRIL 27, 2011
PRION TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHY PROJECTS, RESEARCH FUNDING, BSE VOLUNTARY TESTING UPDATE IN NORTH AMERICA 2011
USA PRION FUNDING 2011
"which includes the ___elimination___ of Prion activities ($5,473,000),"
All Other Emerging and Zoonotic Infectious Diseases CDC‘s FY 2012 request of $52,658,000 for all other emerging and zoonotic infectious disease activities is a decrease of $13,607,000 below the FY 2010 level, which includes the elimination of Prion activities ($5,473,000), a reduction for other cross-cutting infectious disease activities, and administrative savings. These funds support a range of critical emerging and zoonotic infectious disease programs such Lyme Disease, Chronic Fatigue Syndrome, and Special Pathogens, as well as other activities described below.
Einstein once said, 'The definition of insanity is doing the same thing over and over again and expecting different results.'re-transmission studies on TSE's...TSS