Monday, July 16, 2012

Persistence of the bovine spongiform encephalopathy infectious agent in sewage

Persistence of the bovine spongiform encephalopathy infectious agent in sewage

Carlos Maluquer de Motesa, 1, Juan-Carlos Espinosab, Ana Estebanb, Miquel Calvoc, Rosina Gironesa, Juan María Torresb, ,

a Department of Microbiology, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain b Centro de Investigacion en Sanidad Animal, CISA-INIA, Carretera Algete-El Casar s/n, Valdeolmos, 28130 Madrid, Spain c Department of Statistics, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain Received 12 December 2011. Revised 28 May 2012. Accepted 18 June 2012. Available online 7 July 2012., How to Cite or Link Using DOI

Abstract Horizontal transmission of prion diseases through the environment represents a considerable concern. Prions are extremely resistant to inactivation and are thought to enter the environment after burial of animal mortalities or through biosolids from wastewater treatment plants. In addition, deposition of prions in the environment through biological fluids and/or faeces has been proved in the last years. Little is known about the behaviour of prion infectivity in the environment. In this study, the persistence of BSE infectious agent in sewage has been assessed by both PrPRes immunoblotting and mouse bioassay in a long-term incubation study. Results indicated that no PrPRes was detected after 150 day of incubation and consistent with this, a statistical regression model estimated 2-logs decay in 151 day. In contrast, no reduction in infectivity was observed during this period. Similarly, BSE infectivity remained unaltered after incubation in PBS for 265 day, whereas PrPRes levels dropped progressively over the length of the study. These results indicate that in sewage and PBS, prion infectivity persists longer and with different dynamics than its commonly used marker PrPRes. Thus, mathematical models computed on the basis of PrPRes detection were unable to predict inactivation of prion infectivity. It is also reasonable to assume that conventional wastewater treatments with low retention times could have a very limited impact on prion infectivity. This data is essential for the development of accurate risk assessment analysis for BSE and other prion diseases in the environment.


Highlights ► Persistence of BSE agent over 265 day as environmental contaminant in sewage. ► Progressive decay in PrPRes detection: 150 day in sewage needed for 2 logs reduction. ► Conversely, no infectivity decay after 150 day in sewage. ► Inactivation dynamics of PrPRes and infectivity in sewage are different. ► Prediction models based on BSE PrPRes fail to predict BSE infectivity decay in sewage.

Abbreviations BSE, bovine spongiform encephalopathy; CWD, chronic wasting disease; TSE, transmissible spongiform encephalopathies; PrPc, cellular prion protein; PrPSc, scrapie-associated prion protein; PrPRes, protease-resistant prion protein Keywords Prions; BSE; PrPRes; Infectivity; Sewage; Environment


Figures and tables from this article:

Fig. 1. Detection of PrPRes in sewage and PBS contaminated with BSE. Aliquots of each sample were collected and concentrated on the indicated day. After proteinase K treatment, PrPRes was detected by IB.

Fig. 2. Prediction models computed for the PrPRes decay over time. (A) Linear regression curve on the logarithm of the densitometry data obtained for the BSE PrPRes immunoreactive bands observed by IB after incubation in PBS. (B) Linear (blue line) and quadratic (red line) regression curve on the logarithm of the densitometry data obtained after incubation in sewage. (C) Quadratic regression curve on the densitometry data obtained after incubation in sewage. RDU, relative densitometry units. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).

Fig. 3. Statistical analysis of the infectivity data obtained after incubation of BSE in either sewage or PBS for 0, 45, 150 and 265 day. Log-rank tests with the Benjamini and Hochberg's correction were carried out for all incubation times (*p<0.05). Data are expressed as means±standard deviation.

Fig. 4. Statistical analysis of the infectivity data obtained after inoculation of serial dilutions of the BSE inoculum used in this study in BoPrP-Tg110 transgenic mice. Log-rank tests with the Benjamini and Hochberg's correction were carried out for all incubation times (*p<0.05). Data are expressed as means±standard deviation.

Table 1. Infectivity of samples contaminated with BSE and incubated in sewage or PBS for the indicated lengths of time. Data indicates mean survival time±standard deviation.

Table 2. Infectivity of serial dilutions of the BSE inoculum used in this study. Data indicates mean survival time±standard deviation.



Friday, June 29, 2012

Highly Efficient Prion Transmission by Blood Transfusion

Saturday, January 24, 2009

Research Project: Detection of TSE Agents in Livestock, Wildlife, Agricultural Products, and the Environment Location: 2008 Annual Report Research Project: Detection of Transmissible Spongiform Encephalopathy Agents in Livestock, Wildlife, Agricultural Products, and the Environment Location: Foodborne Contaminants Research

2008 Annual Report

1a.Objectives (from AD-416) We will develop highly sensitive diagnostic tests to detect transmissible spongiform encephalopathy (TSE) in livestock and wildlife animal species prior to the onset of clinical disease. We will also develop tests to confirm the presence or absence of TSE disease agents in ingredients of animal origin and decontaminated environments.

1b.Approach (from AD-416) The threat of BSE continues to affect export economics for US meat. Meanwhile scrapie continues to influence sheep profits and herd biosecurity, and CWD is spreading throughout North America. Thus U.S. animal industry stakeholders have identified detection of the TSE infectious agent (prions) as a priority biosecurity research issue essential for prevention of TSE diseases. We will build on our previous successes using mass spectrometry (MS) for high-sensitivity and specificity in detection of PrPsc as a marker for TSE infectivity in blood using a hamster scrapie model. We will also develop a novel PrP-null mouse strain and related myeloma cell culture system for production of monoclonal antibodies (MAb), which may be specific for PrPsc. We will then choose MS or MAb and validate our novel diagnostic for preclinical diagnosis of scrapie in sheep blood. Whereas MS and MAb methods rely on dissolved samples, contamination of agricultural products and environmental surfaces is associated with solid samples. So we will produce a cell culture based assay for TSE infectivity that is surface-adsorbed. After using the relatively convenient hamster model for early development, we will validate this technology for detection of scrapie in sheep brain on meat-and-bone meal and stainless steel. Replacing 5325-32000-007-00D (3/19/2008).

3.Progress Report At this point in the Project, in general, we are completing preliminary studies using our relatively convenient hamster and mouse models, and are starting to work with more agriculturally relevant sheep and deer tissues. We are finding the cervid tissues quite different from rodent tissues, in their requirements for sample workup (e.g., amount and quality of lipid and fiber) and in their expression of TSE infectivity and presence of markers. OSQR required us to establish a new collaboration with a reputable cell biologist, to assist with our cell-based scrapie assay. We now have a new MTA with Dr. Charles Weissmann (Scripps), under which we are sharing cell lines and laboratory protocols. We have completed one part of our speed congenics project to develop PrP-null (disease-resistant) mice for use in antibody generation. After conceiving a new procedure for immunogen enrichment, we performed experimental vaccination of these animals in our facilities. This project relates to NP103 Component 8: Prevention and control of transmissible spongiform encephalopathies. Problem statement 9A: Scrapie; 9B Chronic Wasting Disease (CWD); and 9C: Bovine Spongiform Encephalopathy (BSE).

4.Accomplishments 1. Proteinase K-free method for preparation of samples facilitates TSE blood assay.

The most widely used and regulatory approved methods for detection of Transmissible Spongiform Encephalopathy (TSE) contain a step in which the sample is subjected to digestion by a very strong enzyme, proteinase K, which degrades almost all proteins in the sample except for an Infectious isoform of the normal cellular prion protein, a prion (PrPsc). Although PrPsc has served well as a marker for brain disease, infectivity in the blood is mostly not proteinase K resistant. The proteinase K-free technique developed by ARS scientists in the Foodborne Contaminants Research Unit in Albany, CA will allow scientists to detect infectivity in blood. These efforts will lead to diagnostic tests that will save farmers and ranchers money and resources by allowing them to identify infected animals prior to purchase, sale or slaughter, and keep TSE-infected animals out of the US food supply. This accomplishment addresses NP103 Component 8: Prevention and Control of Transmissible Spongiform Encephalopathies; Problem Statement 9A: Scrapie; 9B: Chronic Wasting Disease (CWD); and 9C: Bovine Spongiform Encephalopathy (BSE).

2. Demonstrated conversion of a non-infectious normal cellular prion protein (PrP) into disease isoform in cell culture.

Although Transmissible Spongiform Encephalopathy (TSE) infectivity can be detected using animal models and mass spectroscopy, a cell culture system offers increased speed and throughput. ARS scientists in the Foodborne Contaminants Research Unit in Albany, CA developed conditions for growth and infection of existing cell cultures and cultures expressing transgenic PrP genes, observing conversion to the disease-associated PrPsc isoform. This method will be further developed to detect infectivity that is adsorbed onto surfaces, such as stainless steel and soil. These efforts will lead to diagnostic tests that will save farmers and ranchers money and resources by allowing them to identify infected areas and equipment before these areas or items can infect their animals. This accomplishment addresses NP103 Component 8: Prevention and Control of Transmissible Spongiform Encephalopathies; Problem Statement 9A: Scrapie; 9B: Chronic Wasting Disease (CWD); and 9C: Bovine Spongiform Encephalopathy (BSE).

5.Significant Activities that Support Special Target Populations None.

6.Technology Transfer Number of New Commercial Licenses Executed 1

Review Publications Bruederle, C.E., Hnasko, R.M., Kraemer, T., Garcia, R.A., Haas, M.J., Marmer, W.N., Carter, J.M. 2008. Prion infected Meat-and-Bone Meal is still infectious after biodiesel production. PLoS Pathogens. Available:

Onisko, B.C., Chen, N., Napoli, J. 2008. The Nuclear Transcription Factor RAR Associates with Neuronal RNA Granules and Suppresses Translation. Journal of Biological Chemistry. 283(30):20841-20847.

Sajnani, G., Pastrana, M.A., Dynin, I.A., Onisko, B.C., Requena, J.R. 2008. Insights on scrapie prion protein (prpsc) structure obtained by limited proteolysis and mass spectrometry. Journal of Molecular Biology. 382(2008):88-98.

FY2006: Tests for prion contamination in soil and water will be developed.

Scrapie Agent (Strain 263K) Can Transmit Disease via the Oral Route after Persistence in Soil over Years

Bjoern Seidel1#*, Achim Thomzig2#, Anne Buschmann3#, Martin H. Groschup3, Rainer Peters1, Michael Beekes2, Konstantin Terytze4

1 Fraunhofer Institute for Molecular Biology und Applied Ecology (IME), Schmallenberg, Germany, 2 P24 -Transmissible Spongiform Encephalopathies, Robert Koch-Institut, Berlin, Germany, 3 Institute for Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Insel Riems, Germany, 4 German Federal Environmental Agency (Umweltbundesamt, UBA), Dessau, Germany

Abstract The persistence of infectious biomolecules in soil constitutes a substantial challenge. This holds particularly true with respect to prions, the causative agents of transmissible spongiform encephalopathies (TSEs) such as scrapie, bovine spongiform encephalopathy (BSE), or chronic wasting disease (CWD). Various studies have indicated that prions are able to persist in soil for years without losing their pathogenic activity. Dissemination of prions into the environment can occur from several sources, e.g., infectious placenta or amniotic fluid of sheep. Furthermore, environmental contamination by saliva, excrements or non-sterilized agricultural organic fertilizer is conceivable. Natural transmission of scrapie in the field seems to occur via the alimentary tract in the majority of cases, and scrapie-free sheep flocks can become infected on pastures where outbreaks of scrapie had been observed before. These findings point to a sustained contagion in the environment, and notably the soil. By using outdoor lysimeters, we simulated a contamination of standard soil with hamster-adapted 263K scrapie prions, and analyzed the presence and biological activity of the soil-associated PrPSc and infectivity by Western blotting and hamster bioassay, respectively. Our results showed that 263K scrapie agent can persist in soil at least over 29 months. Strikingly, not only the contaminated soil itself retained high levels of infectivity, as evidenced by oral administration to Syrian hamsters, but also feeding of aqueous soil extracts was able to induce disease in the reporter animals. We could also demonstrate that PrPSc in soil, extracted after 21 months, provides a catalytically active seed in the protein misfolding cyclic amplification (PMCA) reaction. PMCA opens therefore a perspective for considerably improving the detectability of prions in soil samples from the field.

Prions Adhere to Soil Minerals and Remain Infectious

Christopher J. Johnson1,2, Kristen E. Phillips3, Peter T. Schramm3, Debbie McKenzie2, Judd M. Aiken1,2, Joel A. Pedersen3,4*

1 Program in Cellular and Molecular Biology, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 2 Department of Animal Health and Biomedical Sciences, School of Veterinary Medicine, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 3 Molecular and Environmental Toxicology Center, University of Wisconsin Madison, Madison, Wisconsin, United States of America, 4 Department of Soil Science, University of Wisconsin Madison, Madison, Wisconsin, United States of America

Abstract An unidentified environmental reservoir of infectivity contributes to the natural transmission of prion diseases (transmissible spongiform encephalopathies [TSEs]) in sheep, deer, and elk. Prion infectivity may enter soil environments via shedding from diseased animals and decomposition of infected carcasses. Burial of TSE-infected cattle, sheep, and deer as a means of disposal has resulted in unintentional introduction of prions into subsurface environments. We examined the potential for soil to serve as a TSE reservoir by studying the interaction of the disease-associated prion protein (PrPSc) with common soil minerals. In this study, we demonstrated substantial PrPSc adsorption to two clay minerals, quartz, and four whole soil samples. We quantified the PrPSc-binding capacities of each mineral. Furthermore, we observed that PrPSc desorbed from montmorillonite clay was cleaved at an N-terminal site and the interaction between PrPSc and Mte was strong, making desorption of the protein difficult. Despite cleavage and avid binding, PrPSc bound to Mte remained infectious. Results from our study suggest that PrPSc released into soil environments may be preserved in a bioavailable form, perpetuating prion disease epizootics and exposing other species to the infectious agent.

Synopsis Transmissible spongiform encephalopathies (TSEs) are a group of incurable diseases likely caused by a misfolded form of the prion protein (PrPSc). TSEs include scrapie in sheep, bovine spongiform encephalopathy (“mad cow” disease) in cattle, chronic wasting disease (CWD) in deer and elk, and Creutzfeldt-Jakob disease in humans. Scrapie and CWD are unique among TSEs because they can be transmitted between animals, and the disease agents appear to persist in environments previously inhabited by infected animals. Soil has been hypothesized to act as a reservoir of infectivity, because PrPSc likely enters soil environments through urinary or alimentary shedding and decomposition of infected animals. In this manuscript, the authors test the potential for soil to serve as a reservoir for PrPSc and TSE infectivity. They demonstrate that PrPSc binds to a variety of soil minerals and to whole soils. They also quantitate the levels of protein binding to three common soil minerals and show that the interaction of PrPSc with montmorillonite, a common clay mineral, is remarkably strong. PrPSc bound to Mte remained infectious to laboratory animals, suggesting that soil can serve as a reservoir of TSE infectivity.

Direct Detection of Soil-Bound Prions

Sacha Genovesi1, Liviana Leita2, Paolo Sequi3, Igino Andrighetto4, M. Catia Sorgato1,5, Alessandro Bertoli1*

1 Dipartimento di Chimica Biologica, Università di Padova, Padova, Italy, 2 Istituto Sperimentale per la Nutrizione delle Piante, Gorizia, Italy, 3 Istituto Sperimentale per la Nutrizione delle Piante, Roma, Italy, 4 Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Italy, 5 CNR Istituto di Neuroscienze, Padova, Italy

Abstract Scrapie and chronic wasting disease are contagious prion diseases affecting sheep and cervids, respectively. Studies have indicated that horizontal transmission is important in sustaining these epidemics, and that environmental contamination plays an important role in this. In the perspective of detecting prions in soil samples from the field by more direct methods than animal-based bioassays, we have developed a novel immuno-based approach that visualises in situ the major component (PrPSc) of prions sorbed onto agricultural soil particles. Importantly, the protocol needs no extraction of the protein from soil. Using a cell-based assay of infectivity, we also report that samples of agricultural soil, or quartz sand, acquire prion infectivity after exposure to whole brain homogenates from prion-infected mice. Our data provide further support to the notion that prion-exposed soils retain infectivity, as recently determined in Syrian hamsters intracerebrally or orally challanged with contaminated soils. The cell approach of the potential infectivity of contaminated soil is faster and cheaper than classical animal-based bioassays. Although it suffers from limitations, e.g. it can currently test only a few mouse prion strains, the cell model can nevertheless be applied in its present form to understand how soil composition influences infectivity, and to test prion-inactivating procedures.

now, something i have pondered long about, with the atypical BSE in Texas and Alabama, where, as far as i know, those farms WERE NOT quarantined for 5 years due to an atypical TSE. HOWEVER, the farms of the atypical scrapie from where the mad sheep of mad river valley occurred, these farms were quarantined. ...

----- Original Message -----

From: Terry S. Singeltary Sr.

To: mhtml:%7B33B38F65-8D2E-434D-8F9B-8BDCD77D3066%7Dmid://00000169/!

Sent: Sunday, February 25, 2007 12:35 PM


Greetings USDA,

I respectfully request the final results of the mouse bio-assays test that were to have supposedly began 2+ years late, 5 years ago, on the imported sheep from Belgium ?

WHAT happened to the test results and MOUSE BIO-ASSAYS of those imported sheep from Belgium that were confiscated and slaughtered from the Faillace's, what sort of TSE did these animals have ?

WERE they atypical scrapie, BSE, and or typical scrapie ?

HOW much longer will you refuse to give us this information ? and for what reason ?

WHY is it that the Farm of the Mad Sheep of Mad River Valley were quarantined for 5 years, but none of these farms from Texas and Alabama with Atypical TSE in the Bovine, they have not been quarantined for 5 years,why not, with the real risk of BSE to sheep, whom is to say this was not BSE ?


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Monday, September 1, 2008


Greetings again BSE-L members,

I had a pleasant surprise this past Saturday. I got an unexpected package from O.I.G. on my old F.O.I.A. request, of the final test results of the infamous mad sheep of mad river valley. IF you all remember, back on Thu, 24 Apr 2008 15:00:20 -0500 I wrote ;

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i remember a few years back ???


that a study showed the prion uptake in a tomato plant, not that this would surprise me ;

56. Members considered that there is no evidence that crops grown on the land which received composted excreta from BSE-challenged animals pose a TSE risk to humans or animals. One member suggested that, as some of these animals are orally challenged with high doses of BSE-infected materials, and the distribution of infectivity in the digestive system is not completely understood, it might be premature to conclude that there is no infective agent in the manure. Furthermore, an unpublished study had indicated low level absorption of PrP from soil by tomato plants although it should be noted that this study had not been repeated. Details of this work would be sent to the SEAC Secretary. Dr Matthews explained that most of the manure from animals challenged with high doses of BSE had already been composted and used for coppicing. Members agreed that the risks from disposal of residual manure from experimental animals would be much less than historic risks of on farm contamination from naturally infected animals at the height of the BSE epidemic.

SRM are certain cattle tissues capable of transmitting BSE. There is no human health risk assessment to indicate the absence of human health concerns associated with use of composted SRM domestically. To date, scientific evidence has not been able to demonstrate that composting destroys prions. Although domestic use would pose a negligible risk to livestock, there is a potential risk to humans via direct ingestion of the compost or of compost particles adhered to skin or plant material (e.g. carrots). Another potential route of exposure is by ingestion of prions that have been taken up by plants. It has been proven that bacteria are readily taken up by some plants (e.g. E. coli in lettuce) thus the uptake of prions by plants cannot be precluded or dismissed at this time. As a science-based regulator, the CFIA cannot change the policy on this issue without a risk assessment demonstrating that the use of composted SRM poses an acceptable risk to humans.

The BSE Inquiry / Statement No 19B (supplementary) Dr Alan Colchester Issued 06/08/1999 (not scheduled to give oral evidence) SECOND STATEMENT TO THE BSE INQUIRY Dr A Colchester BA BM BCh PhD FRCP Reader in Neurosciences & Computing, University of Kent at Canterbury; Consultant Neurologist, Guy’s Hospital London and William Harvey Hospital Ashford April 1999


88. Natural decay: Infectivity persists for a long time in the environment. A study by Palsson in 1979 showed how scrapie was contracted by healthy sheep, after they had grazed on land which had previously been grazed by scrapie-infected sheep, even though the land had lain fallow for three years before the healthy sheep were introduced. Brown also quoted an early experiment of his own (1991), where he had buried scrapie-infected hamster brain and found that he could still detect substantial infectivity three years later near where the material had been placed. 89. Potential environmental routes of infection: Brown discusses the various possible scenarios, including surface or subsurface deposits of TSE-contaminated material, which would lead to a build-up of long-lasting infectivity. Birds feeding on animal remains (such as gulls visiting landfill sites) could disperse infectivity. Other animals could become vectors if they later grazed on contaminated land. "A further question concerns the risk of contamination of the surrounding water table or even surface water channels, by effluents and discarded solid wastes from treatment plants. A reasonable conclusion is that there is a potential for human infection to result from environmental contamination by BSE-infected tissue residues. The potential cannot be quantified because of the huge numbers of uncertainties and assumptions that attend each stage of the disposal process". These comments, from a long established authority on TSEs, closely echo my own statements which were based on a recent examination of all the evidence. 90. Susceptibility: It is likely that transmissibility of the disease to humans in vivo is probably low, because sheep that die from scrapie and cattle that die from BSE are probably a small fraction of the exposed population. However, no definitive data are available.

91. Recommendations for disposal procedures: Brown recommends that material which is actually or potentially contaminated by BSE should be: 1) exposed to caustic soda; 2) thoroughly incinerated under carefully inspected conditions; and 3) that any residue should be buried in landfill, to a depth which would minimise any subsequent animal or human exposure, in areas that would not intersect with any potable water-table source.

92. This review and recommendations from Brown have particular importance. Brown is one of the world's foremost authorities on TSEs and is a senior researcher in the US National Institutes of Health (NIH). It is notable that such a respected authority is forthright in acknowledging the existence of potential risks, and in identifying the appropriate measures necessary to safeguard public health. Paper by SM Cousens, L Linsell, PG Smith, Dr M Chandrakumar, JW Wilesmith, RSG Knight, M Zeidler, G Stewart, RG Will, "Geographical distribution of variant CJD in the UK (excluding Northern Ireland)". Lancet 353:18-21, 2 nd January 1999 93. The above paper {Appendix 41 (02/01/99)} (J/L/353/18) examined the possibility that patients with vCJD (variant CJD) might live closer to rendering factories than would be expected by chance. All 26 cases of vCJD in the UK with onset up to 31 st August 1998 were studied. The incubation period of vCJD is not known but by analogy with other human TSEs could lie within the range 5-25 years. If vCJD had arisen by exposure to rendering products, such exposure might plausibly have occurred 8-10 years before the onset of symptoms. The authors were able to obtain the addresses of all rendering plants in the UK which were in production in 1988. For each case of vCJD, the distance from the place of residence on 1st January 1998 to the nearest rendering plant was calculated


Infectivity surviving ashing to 600*C is (in my opinion) degradable but infective. based on Bown & Gajdusek, (1991), landfill and burial may be assumed to have a reduction factor of 98% (i.e. a factor of 50) over 3 years. CJD-infected brain-tissue remained infectious after storing at room-temperature for 22 months (Tateishi et al, 1988). Scrapie agent is known to remain viable after at least 30 months of desiccation (Wilson et al, 1950). and pastures that had been grazed by scrapie-infected sheep still appeared to be contaminated with scrapie agent three years after they were last occupied by sheep (Palsson, 1979).



please see full text ;

Thursday, February 17, 2011

Environmental Sources of Scrapie Prions

Thursday, May 31, 2012

CHRONIC WASTING DISEASE CWD PRION2012 Aerosol, Inhalation transmission, Scrapie, cats, species barrier, burial, and more

Friday, February 25, 2011

Soil clay content underlies prion infection odds

PRION 2010

International Prion Congress: From agent to disease September 8–11, 2010 Salzburg, Austria



Survival and Limited Spread of TSE Infectivity after Burial

Karen Fernie, Allister Smith and Robert A. Somerville The Roslin Institute and R(D)SVS; University of Edinburgh; Roslin, Scotland UK

Scrapie and chronic wasting disease probably spread via environmental routes, and there are also concerns about BSE infection remaining in the environment after carcass burial or waste 3disposal. In two demonstration experiments we are determining survival and migration of TSE infectivity when buried for up to five years, as an uncontained point source or within bovine heads. Firstly boluses of TSE infected mouse brain were buried in lysimeters containing either sandy or clay soil. Migration from the boluses is being assessed from soil cores taken over time. With the exception of a very small amount of infectivity found 25 cm from the bolus in sandy soil after 12 months, no other infectivity has been detected up to three years. Secondly, ten bovine heads were spiked with TSE infected mouse brain and buried in the two soil types. Pairs of heads have been exhumed annually and assessed for infectivity within and around them. After one year and after two years, infectivity was detected in most intracranial samples and in some of the soil samples taken from immediately surrounding the heads. The infectivity assays for the samples in and around the heads exhumed at years three and four are underway. These data show that TSE infectivity can survive burial for long periods but migrates slowly. Risk assessments should take into account the likely long survival rate when infected material has been buried.

The authors gratefully acknowledge funding from DEFRA.

Wednesday, September 08, 2010



Detection of Protease-Resistant Prion Protein in Water from a CWD-Endemic Area


Detection of Protease-Resistant Prion Protein in Water from a CWD-Endemic Area

Tracy A. Nichols*1,2, Bruce Pulford1, Christy Wyckoff1,2, Crystal Meyerett1, Brady Michel1, Kevin Gertig3, Jean E. Jewell4, Glenn C. Telling5 and M.D. Zabel1 1Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA 2National Wildlife Research Center, Wildlife Services, United States Department of Agriculture, Fort Collins, Colorado, 80521, USA 3Fort Collins Water and Treatment Operations, Fort Collins, Colorado, 80521, USA 4 Department of Veterinary Sciences, Wyoming State Veterinary Laboratory, University of Wyoming, Laramie, Wyoming, 82070, USA 5Department of Microbiology, Immunology, Molecular Genetics and Neurology, Sanders Brown Center on Aging, University of Kentucky, Lexington, Kentucky, 40536, USA * Corresponding author-

Chronic wasting disease (CWD) is the only known transmissible spongiform encephalopathy affecting free-ranging wildlife. Experimental and epidemiological data indicate that CWD can be transmitted horizontally and via blood and saliva, although the exact mode of natural transmission remains unknown. Substantial evidence suggests that prions can persist in the environment, implicating it as a potential prion reservoir and transmission vehicle. CWD- positive animals can contribute to environmental prion load via biological materials including saliva, blood, urine and feces, shedding several times their body weight in possibly infectious excreta in their lifetime, as well as through decomposing carcasses. Sensitivity limitations of conventional assays hamper evaluation of environmental prion loads in water. Here we show the ability of serial protein misfolding cyclic amplification (sPMCA) to amplify minute amounts of CWD prions in spiked water samples at a 1:1 x106 , and protease-resistant prions in environmental and municipal-processing water samples from a CWD endemic area. Detection of CWD prions correlated with increased total organic carbon in water runoff from melting winter snowpack. These data suggest prolonged persistence and accumulation of prions in the environment that may promote CWD transmission.


The data presented here demonstrate that sPMCA can detect low levels of PrPCWD in the environment, corroborate previous biological and experimental data suggesting long term persistence of prions in the environment2,3 and imply that PrPCWD accumulation over time may contribute to transmission of CWD in areas where it has been endemic for decades. This work demonstrates the utility of sPMCA to evaluate other environmental water sources for PrPCWD, including smaller bodies of water such as vernal pools and wallows, where large numbers of cervids congregate and into which prions from infected animals may be shed and concentrated to infectious levels.

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Wednesday, June 27, 2012

First US BSE Case Since 2006 Underscores Need for Vigilance

Neurology Today 21 June 2012

Thursday, March 29, 2012

atypical Nor-98 Scrapie has spread from coast to coast in the USA 2012

NIAA Annual Conference April 11-14, 2011San Antonio, Texas

Monday, June 11, 2012

another atypical Nor-98 Scrapie case documented in Canada for 2012

Tuesday, June 26, 2012

Creutzfeldt Jakob Disease Human TSE report update North America, Canada, Mexico, and USDA PRION UNIT as of May 18, 2012

type determination pending Creutzfeldt Jakob Disease (tdpCJD), is on the rise in Canada and the USA

Wednesday, May 16, 2012

Alzheimer’s disease and Transmissible Spongiform Encephalopathy prion disease, Iatrogenic, what if ?

Proposal ID: 29403


Terry S. Singeltary Sr.

P.O. Box 42

Bacliff, Texas USA 77518