Saturday, August 07, 2010

Select Tissue Mineral Concentrations and Chronic Wasting Disease Status in Mule Deer from North-central Colorado

Greetings all,

confucius ponders, what if ;

I know that there are other modes of potential and proven transmission in human and animal TSE.

What if you had metals and mad deer feed (banned animal protein), all mixed in one, would it be possible that the metals caused the deer to be more susceptible, to the infectious deer feed, which all was mixed in ?

Or environmental metals, and either environmental contact with cwd or feed with cwd, what if ?


Tissue Mineral Concentrations and Chronic Wasting Disease Status in Mule Deer from North-central Colorado

Lisa L. Wolfe1,4, Mary M. Conner2, Cathy L. Bedwell3, Paul M. Lukacs1 and Michael W. Miller1 1 Colorado Division of Wildlife, Wildlife Research Center, 317 West Prospect Road, Fort Collins, Colorado 80526-2097, USA 2 Department of Wildland Resources, Utah State University, Logan, Utah 84322-5230, USA 3 Colorado State University Veterinary Diagnostic Laboratories, Fort Collins, Colorado 80523, USA 4 Corresponding author (email: )

ABSTRACT: Trace mineral imbalances have been suggested as having a causative or contributory role in chronic wasting disease (CWD), a prion disease of several North American cervid species. To begin exploring relationships between tissue mineral concentrations and CWD in natural systems, we measured liver tissue concentrations of copper, manganese, and molybdenum in samples from 447 apparently healthy, adult (2 yr old) mule deer (Odocoileus hemionus) culled or vehicle killed from free-ranging populations in north-central Colorado, United States, where CWD occurs naturally; we also measured copper concentrations in brain-stem (medulla oblongata at the obex) tissue from 181 of these deer. Analyses revealed a wide range of concentrations of all three minerals among sampled deer (copper: 5.6–331 ppm in liver, 1.5–31.9 ppm in obex; manganese: 0.1–21.4 ppm in liver; molybdenum: 0.5–4.0 ppm in liver). Bayesian multiple regression analysis revealed a negative association between obex copper (–0.097; 95% credible interval –0.192 to –0.006) and the probability of sampled deer also being infected with CWD, as well as a positive association between liver manganese (0.158; 95% credible interval 0.066 to 0.253) and probability of infection. We could not discern whether the tendencies toward lower brain-stem copper concentrations or higher systemic manganese concentrations in infected deer preceded prion infection or rather were the result of infection and its subsequent effects, although the distribution of trace mineral concentrations in infected deer seemed more suggestive of the latter.

Key words: Chronic wasting disease (CWD), copper (Cu), manganese (Mn), molybdenum (Mo), mule deer, Odocoileus hemionus, prion, trace mineral.

Complexed (organic) trace minerals are utilized in several ADM Alliance Nutrition deer feeds.

Research shows that rations supplemented with complexed (organic) trace minerals enhance reproductive performance.

The zinc portion of this complexed (organic) mineral has been shown to have positive effects on hoof and skin condition.

The cobalt component of this complexed (organic) trace mineral is essential for the synthesis of vitamin B12, a coenzyme and needed for the production of red blood cells.

Copper from the complexed (organic) trace mineral is involved in the proper function of bacteria-fighting cells (macrophages and neutrophils).

Manganese, a part of the complexed (organic) trace minerals, is essential in the process of blood detoxification within the liver.

CRITICAL MASS Concentrated Vitamin/Mineral Supplement for Deer Feed Guaranteed Analysis Crude Protein Minimum 2% Crude Fat Minimum .5% Crude Fiber Maximum 3 % Ash Maximum 90% Calcium (Ca) Minimum 15% Maximum 17 % Phosphorus (P) Minimum 8.25 % Selenium (Se) Minimum 9ppm Vitamin A Minimum 150,000 IU/lb Vitamin D3 Minimum 45,000 IU/lb Vitamin E Minimum 125 IU/lb

Ingredient Statement

Dicalcium Phosphate, Salt, Calcium Carbonate, Distillers Grains Dehydrated, Potassium Chloride, Magnesium Oxide, Saccaromyces Cerevisiae, dried Aspergillus oryzae fermentation product, dried Aspergillus oryzae fermentation extract, dried Propionibacterium freudenreichil fermentation product, dried lactobacillus acidophilus fermentation product, dried Lactobacillus casei fermentation product, dried Enterococcus faecium fermentation product, dried Lactobacillus fermentation product, dried Pediococcus cerevisiae fermentation product, dried Aspergillus niger fermentation extract, dried Trichoderma viride fermentation extract, dried Bacillus subtilis fermentation product, dried Bacillus lichenifomis fermentation product, sodium aluminosilicate.Zinc Oxide, Ferrous Sulfate, Sodium Bicarbonate, Biotin, Manganese Sulfate, Copper Sulfate, Natural and Artificial Flavors, Sodium Saccharin, Roughage Products, Attapulagite Clay, and TBHQ (to preserve flavor), Zinc Proteinate, Sodium Selenite, Non-Nutritive Sweetners, Propylene Glycol, Corn Flour, Vitamin E Supplement, Vitamin A Acetate, Cobalt Sulfate, Vitamin D3 Supplement, Ascorbic Acid, Ethylenediamine Dihydriodide, Menadione Sodium Bisulfate Complex (source of Vitamin K), Dried Whey, Iron Proteinate, DL Methionine, L-Lysine, Magnesium Sulfate, Manganese Proteinate, Zinc Sulfate, Silicon Dioxide, Niacinamide, Copper Proteinate, Selenium Yeast, Brewers Dried yeast, Calcium Pantothenate, Riboflavin, Vitmain B12 Supplement, Thiamine Mononitrate, Pyridoxine Hydrochloride, Folic Acid, Calcium Iodate

User Information: Critical Mass can be used by hunters, breeders, hunting clubs, outfitters, and wildlife enthusiasts of all types. Whether you are practicing a quality deer management program, or are scientific breeders looking to supplement and insure optimal nutrition for your prized herd, Critical Mass will become an important part of your overall management program.

Directions for Use: *Consult your State game laws before using!* Select a site near trails, food sources, water, or shelter.* Clear leaves and vegetation in a 3 foot Diameter circle.*Lightly loosen the top soil,*pour ½ bag (25 lbs.) of Critical Mass over the dirt circle.*One supplement site per 40 acres will reduce potential user conflicts.

Station Maintenance: Re-check site monthly; and refresh when necessary Feed year round.*With “Free Choice” supplementation, deer naturally seek the nutrition they need. Site visitation may vary, according to nutritional need and seasonal cycles.

Caution: Follow label directions. The addition to feed of higher levels of this premix containing selenium is not permitted.

Warning!! Contains copper! DO NOT feed to Sheep and other sensitive livestock or animals.

Manufactured For: Buckhorn Trophy Products A division of Bio-Tec Research, Inc. Pittsville, WI 54466 (800) 518-8019 Net Weight 50 LBS (22.68 kg) or Net Weight 25 LBS (11.34 kg)

The following is an “average analysis” of additional nutrient levels not listed on the Critical Mass feed tag (above);

Protein 3% min. Fat 1% min. Vit. A 155,500 IU/lb. min. Vit. D 46,250 IU/lb. min. Vit. E 130 IU/lb.min. Vit. C 120 ppm min. Vit. K 14 ppm min. Calcium 16.% min. 16.75%max. Phosphorus 8.75 % min. Magnesium 1.3 % min. Potassium 1 % min. Salt 23.5% min. Copper 660 ppm min. Zinc 4250 ppm min. Iron 1775 ppm min Manganese 1275 ppm min. Selenium 9.5 ppm min. Cobalt 65 ppm min. Iodine 64 ppm min. Thiamin (B-1) 7 ppm Riboflavin (B-2) 7 ppm Niacin (B-3) 50 ppm Pant. Acid (B-5) 12 ppm Pyridox. hcl (B-6) 7 ppm Biotin (B-7) 20 ppm Folic Acid (B-9) 2.25 ppm Vit B12 3.25 ug./lb Choline 125 ppm CFU’s / Lb. 256 million Enzyme act./lb. 1,650 ug

There are many “features” in Critical Mass that are not readily observable by reading the tag, but will certainly affect cervid performance. Compare the “Guaranteed Analysis” on the Vitamin/Mineral Supplement you are currently using to “Critical Mass”.


Grain Products, Roughage Products (not more than 35%), Processed GrainBy-Products, Plant Protein Products, Forage Products,

__Animal Protein Products__,

L-Lysine, Calcium Carbonate, Salt, Monocalcium/DicalciumPhosphate, Yeast Culture, Magnesium Oxide, Cobalt Carbonate, BasicCopper Chloride, Manganese Sulfate, Manganous Oxide, Sodium Selenite,Zinc Sulfate, Zinc Oxide, Sodium Selenite, Potassium Iodide,Ethylenediamine Dihydriodide, Vitamin E Supplement, Vitamin ASupplement, Vitamin D3 Supplement, Mineral Oil, Mold Inhibitor, CalciumLignin Sulfonate, Vitamin B12 Supplement, Menadione Sodium BisulfiteComplex, Calcium Pantothenate, Riboflavin, Niacin, Biotin, Folic Acid,Pyridoxine Hydrochloride, Mineral Oil, Chromium Tripicolinate


Deer Builder Pellets is designed to be fed to deer under rangeconditions or deer that require higher levels of protein. Feed to deerduring gestation, fawning, lactation, antler growth and pre-rut, allphases which require a higher level of nutrition. Provide adequateamounts of good quality roughage and fresh water at all times.


April 9, 2001 WARNING LETTER


Brian J. Raymond, Owner Sandy Lake Mills 26 Mill Street P.O. Box 117 Sandy Lake, PA 16145 PHILADELPHIA DISTRICT

Tel: 215-597-4390

Dear Mr. Raymond:

Food and Drug Administration Investigator Gregory E. Beichner conducted an inspection of your animal feed manufacturing operation, located in Sandy Lake, Pennsylvania, on March 23, 2001, and determined that your firm manufactures animal feeds including feeds containing prohibited materials. The inspection found significant deviations from the requirements set forth in Title 21, code of Federal Regulations, part 589.2000 - Animal Proteins Prohibited in Ruminant Feed. The regulation is intended to prevent the establishment and amplification of Bovine Spongiform Encephalopathy (BSE) . Such deviations cause products being manufactured at this facility to be misbranded within the meaning of Section 403(f), of the Federal Food, Drug, and Cosmetic Act (the Act).

Our investigation found failure to label your swine feed with the required cautionary statement "Do Not Feed to cattle or other Ruminants" The FDA suggests that the statement be distinguished by different type-size or color or other means of highlighting the statement so that it is easily noticed by a purchaser.

In addition, we note that you are using approximately 140 pounds of cracked corn to flush your mixer used in the manufacture of animal feeds containing prohibited material. This flushed material is fed to wild game including deer, a ruminant animal. Feed material which may potentially contain prohibited material should not be fed to ruminant animals which may become part of the food chain.

confucius is confused again ?

could it be, could it be _part_ of the puzzle of deer or elk CWD ?

Manganese Enhances Prion Protein Survival in Model Soils and Increases Prion Infectivity to Cells

Paul Davies, David R. Brown*

Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom

Abstract Top

Prion diseases are considered to be transmissible. The existence of sporadic forms of prion diseases such as scrapie implies an environmental source for the infectious agent. This would suggest that under certain conditions the prion protein, the accepted agent of transmission, can survive in the environment. We have developed a novel technique to extract the prion protein from soil matrices. Previous studies have suggested that environmental manganese is a possible risk factor for prion diseases. We have shown that exposure to manganese is a soil matrix causes a dramatic increase in prion protein survival (~10 fold) over a two year period. We have also shown that manganese increases infectivity of mouse passaged scrapie to culture cells by 2 logs. These results clearly verify that manganese is a risk factor for both the survival of the infectious agent in the environment and its transmissibility.

Mad Cows and Metals By Katherine Unger ScienceNOW Daily News 31 May 2006

The proteins that, when mangled, cause "Mad Cow" and similar diseases also help regulate how yeast cells metabolize metals, biochemists report. Exposure to high levels of metals can coax proteins called prions to adopt an abnormal disease-causing conformation, the researchers found. That could explain why outbreaks of prion diseases have popped up in Iceland, Slovakia, and Colorado--regions with soils high in manganese. Mad Cow disease in cattle, scrapie in sheep, and Creutzfeldt-Jakob disease in humans are all deadly and transmissible conditions in which the brain degenerates. All seemed to be caused by prion proteins that have changed shape so that enzymes can no longer break them down. This altered conformation is widely thought to be responsible for the diseases, because the tangled and essentially indestructible proteins collect in brain tissue (ScienceNOW, July 29 2004). Studies have shown that some metals bind to prion proteins, leading some scientists to wonder whether metals are involved in the shape shift.

Now, biochemist Gerd Multhaup of the Free University of Berlin and colleagues have shown that prions alter metal metabolism in yeast. As a first step, they took a species of yeast that does not normally make prions and added prions that don't cause disease. Copper levels increased 1.6-fold inside these cells while manganese decreased by half compared to yeast without prion proteins, the researchers report in a paper to be published 13 June in Biochemistry. The researchers then added copper or manganese to the growth medium to form 1 to 5 millimolar concentrations; both additions transformed the prions to the indestructible form.

At one time a skeptic, Multhaup says the new findings and prior evidence are starting to convince him that exposure to metal-enriched food and soils "is a risk factor" that increases susceptibility to prion diseases.

David Brown, a neurochemist at the University of Bath in the United Kingdom, doesn't go that far but says the paper is "a good confirmation" that metals strongly influence prions. And yeast molecular biologist Mick Tuite of the University of Kent in the United Kingdom says that "any attempt to try and model prion conversion in vivo is an important step forward." But he questions the relevance of a yeast species that doesn't usually have prions and says more work in necessary to prove prions behave the same way in mammals.

PLEASE note, most important ;

"exposure to metal-enriched food and soils "is a risk factor" that increases susceptibility to prion diseases." ...

Subject: FATEPriDE Environmental Factors that Affect the Development of Prion Diseases Date: February 18, 2006 at 9:24 am PST


Environmental Factors that Affect the Development of Prion Diseases.

Project funded by the European Commission under the Quality of Life Programme.

Contract No: QLK4-CT-2002-02723

Project No: QLRT-2001-02723

Start Date

1st January 2003


36 months plus 6 month extension


1. The University of Bristol, UK (Co-ordinator) 2. National Environment Research Council-The British Geological Society, UK 3. University of Bath, UK 4. Free University of Berlin, Germany 5. University of Iceland, Iceland 6. Universita degli studi di Perugia, Italy 7. Universite Joseph Fourier Grenoble, France 8. Alpine Institute of Environmental Dynamics, France


The work proposed here brings together top EU geo and biochemists focusing on determining the environmental factors that affect the development of prion diseases such as scrapie, bovine spongiform enchpalitis (BSE), chronic wasting disease (CWD) and Creutzfeld-Jacobs disease (CJD). First the geographical distribution of manganese and copper in soils will be investigated as risk factors. This will be undertaken due to the fact that prion diseases often are found in clusters. It now has been established that the normal metal for prion protein is copper but if that metal is replaced with manganese, the structure of the prion protein is altered. The role of organophosphate pesticides will also be investigated because it has been suggested that copper is complexed with organophosphate, preventing copper absorption.


There is clear evidence that the occurrence of prion diseases often has a non-random distribution, suggesting a link to some environmental factors. The work proposed here will investigate risk factors, including the role of trace elements and organophosphates. Analysis of regional variation in local manganese/copper levels will be determined and compared to the incidence of the diseases. The ability of manganese and/or organophosphates in influencing conversion of the prion protein to an abnormal and/or infectious protein will be determined. In combination with geographical occurrence and geo-chemical considerations this program will identify whether these environmental considerations should be acted upon to bring about effective prevention or at least risk minimalisation of prion diseases in the EU and further afield.

Description of the Work

Recently it has been suggested that disbalance in dietary trace-elements and/or exposure to organophosphates might either cause or be a risk factor for prion disease development. In particular, high incidence of scrapie (e.g. in Iceland), chronic wasting disease, and in Slovakia and Italy CJD are associated with regions where soil and foliage are reported to be low in copper and high in manganese. This proposal will address whether exposure to a diet that has a high manganese/copper ratio can influence prion disease will also be addressed. In particular, we shall investigate this theory at the level of protein, cells, animals as well as geographical and geo-chemical associations with prion diseases. Animal models of prion disease and sheep from farms in regions of high scrapie will be investigated for a possible influence of level of manganese and copper on incidence or onset of these diseases. Bio-chemical and biophysical techniques will be used to investigate interaction of the prion protein with copper and manganese to determine the mechanism by which Mn substitution for Cu influences conversion to the abnormal isoform of the protein and whether such conversion results in protein that is infectious in mouse bioassay for infectivity. Additionally, a cell culture model will be used to generate abnormal prion protein by exposure to manganese. Cell culture model of infection will be used to assay whether prion disease alters manganese metabolism and transport of manganese into cells. The level of expression of the prion protein is in itself a risk factor for prion disease as it shortens the incubation time for the disease. This research will result in understanding of the role of disbalance in the trace elements Cu and Mn on the onset and mechanisms behind the occurrence of prion diseases and will for the first time define whether there are environmental risk factors for prion diseases.

Milestones and Expected Results

The study proposed here will produce a geo-chemical map of Europe for manganese and copper. These maps will be used to target field areas where prion diseases have occurred as clusters. The bio-chemical studies will establish whether the replacement of manganese for copper in prion protein is a risk factor for the disease _development_. Organophosphate will also be investigated as a risk factor. The study aims at minimising the risk of prion diseases for humans and animals in the EU.

a) As regards the involvement of organophosphates in the origin of BSE, no new scientific information providing evidence or supporting the hypothesis by valid data became available after the adoption of the last opinion of the SSC on this issue. Consequently there is no reason for modifying the existing opinions. b) Regarding the possibility of OP poisoning, the European legislation for registration of plant protection products and veterinary medicines ? addressed in the enquiries ? provide the basis for safe use of registered compounds and their formulations. Regarding the alleged intoxication cases reported and OP exposure it must be concluded that safety measures may not have been strictly followed.


Brown, D.R., Qin, K., Herms, J.W., Madlung, A., Manson, J., Strome, R., Fraser, P.E., Kruck, T., von Bohlen, A., Schulz- Schaeffer, W., Giese, A., Westaway, D. and Kretzschmar, H. (1997) The Cellular Prion Protein Binds Copper In Vivo, Nature, 390, 684-7. Purdey, M. (2000) Ecosystems Supporting Clusters of Sporadic TSEs Demonstrate Excesses of the Radical- Generating Divalent Cation Manganese and Deficiencies of Antioxidant Co-Factors Cu, Se, Fe, Zn Medical Hypotheses, 54, 278-306. Scientific Steering Committee, 1998. Opinion on possible links between BSE and Organophosphates. Adopted on 25-26 June 1998 Scientific Steering Committee, 2001. Opinion on Hypotheses on the origin and transmission of BSE. Adopted on 29-30 November 2001.



The Chair explained that FATEPriDE is a multi-centre European Union funded project that examined the possible influence of environmental trace elements on the occurrence of TSEs. 36. Professor David Brown (University of Bath) explained that the project had principally studied potential interactions between prion disease and copper and manganese, although interactions with other environmental factors such as organophosphates had also been assessed. No link, other than with manganese, between many environmental factors studied, including organophosphates, and TSEs was found. The key experiments and findings had been summarised in SEAC paper 97/4. The main conclusions were that manganese binds to PrP with similar affinity to known manganese binding proteins, induces conformational change in PrP, catalyses PrP aggregation, induces protease resistance in PrP, increases PrP expression levels and increases cellular susceptibility to prion infection. Manganese had also been found at high levels on farms with a high classical scrapie incidence and manganese was found to increase the stability of PrP in soil. Although it had been the intention to create maps of bioavailable manganese and compare those to similar maps of TSE hotspots, this had not been possible as no data of sufficient precision relating the location of BSE or scrapie cases was made available. Further studies were required to investigate the interactions of manganese and prions.

37. Members noted that the study suggested an association between high levels of bioavailable manganese, low levels of bioavailable copper and classical scrapie in field studies. However, it was likely that other factors such as soil pH and organic matter may also be involved. It was acknowledged that it was very difficult in environmental studies to exclude potential confounding factors. The experimental and field data suggested that manganese may influence the susceptibility to TSEs.

However, there was no evidence that environmental factors, including manganese, cause disease.

38. Members noted that data on BSE should allow spatial mapping of cases, however sheep movements were so complex that it is not possible to create similar maps for classical or atypical scrapie. 39. Members suggested that further research could investigate the differential stability of a range of TSE agents bound with manganese in soil, although other modifying factors in soil such as 12 © SEAC 2006 soil content and pH are likely. In addition, further animal studies could examine the effect of manganese on a range of TSE agents.



Organophosphate Studies

6. Studies using phosmet (an organophosphate pesticide) were carried out throughout the project. No relationship between this compound and the potential to cause a TSE were identified. In studies with oral dosing of rats, it was shown that PrP expression levels increased in the brain but there was no association between this and formation of proteinase K (PK) resistant PrP.


12. A model of seed protein aggregation and fibril formation was established using PrP charged with Mn2+. PrP-Mn2+ was found to form small circular aggregates able to catalyse further protein aggregation and fibrilisation of PrP. This model unlike other published models (for example those of Baskakov et al.1) does not require the presence of denaturants and is not an autocatalytic process (i.e. the substrate of the reaction did not aggregate). The results suggest that Mn2+ may play a role in the formation of prion seeds

__although further studies showed that this material was not infectious in mouse bioassay.__


24. The project also generated information concerning the relation of TSEs to environmental factors: • __Potentially no role for organophosphates in TSEs.__ • Increased Mn in the diet results in higher PrP levels in the brain. • No conclusion is yet possible in terms of the relationship between environmental trace element concentrations and the geographical occurrence of TSEs (classical scrapie or BSE). • Some confirmation was provided that in some specific farms occurrence of classical scrapie correlates with high Mn levels.


Phosmet induces up-regulation of surface levels of the cellular prion protein. Neuroreport. 9(7):1391-1395, May 11, 1998. Gordon, Irit 1; Abdulla, Elizabeth M. 1; Campbell, Iain C. 1; Whatley, Stephen A. 1,2 Abstract: CHRONIC (2 day) exposure of human neuroblastoma cells to the organophosphate pesticide phosmet induced a marked concentration-dependent increase in the levels of PrP present on the cell surface as assessed by biotin labelling and immunoprecipitation. Levels of both phospholipase C (PIPLC)-releasable and non-releasable forms of PrP were increased on the plasma membrane. These increases appear to be due to post-transcriptional mechanisms, since PrP mRNA levels as assessed by Northern blotting were unaffected by phosmet treatment. These data raise the possibility that phosmet exposure could increase the _susceptibility to the prion agent by altering the levels of accessible PrP_.

(C) Lippincott-Raven Publishers.

or, what about oral consumption either of animal protein in feed, or animal carcass scavengering, or environmental there from ?

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.

PMID: 6997404

Experimental oral transmission of chronic wasting disease to red deer (Cervus elaphus elaphus): Early detection and late stage distribution of protease-resistant prion protein

Aru Balachandran, Noel P. Harrington, James Algire, Andrei Soutyrine, Terry R. Spraker, Martin Jeffrey, Lorenzo González, Katherine I. O’Rourke

Abstract —

Chronic wasting disease (CWD), an important emerging prion disease of cervids, is readily transmitted by intracerebral or oral inoculation from deer-to-deer and elk-to-elk, suggesting the latter is a natural route of exposure. Studies of host range susceptibility to oral infection, particularly of those species found in habitats where CWD currently exists are imperative. This report describes the experimental transmission of CWD to red deer following oral inoculation with infectious CWD material of elk origin. At 18 to 20 months post-inoculation, mild to moderate neurological signs and weight loss were observed and animals were euthanized and tested using 3 conventional immunological assays. The data indicate that red deer are susceptible to oral challenge and that tissues currently used for CWD diagnosis show strong abnormal prion (PrPCWD) accumulation. Widespread peripheral PrPCWD deposition involves lymphoreticular tissues, endocrine tissues, and cardiac muscle and suggests a potential source of prion infectivity, a means of horizontal transmission and carrier state.

Can Vet J 2010;51:169–178

Chronic wasting disease (CWD), an important emerging prion disease of cervids, is readily transmitted by intracerebral or oral inoculation from deer-to-deer and elk-to-elk, suggesting the latter is a natural route of exposure.

Title: Experimental oral transmission of chronic wasting disease (CWD) to red deer (Cervus elaphus elaphus): early detection and late stage distribution of protease-resistant protein (PrP-res)

Balachandran, A - CANADIAN FOOD INSPCTN AG Harrington, Noel - CANADIAN FOOD INSPCTN AG Algire, James - CANADIAN FOOD INSPCTN AG Souyrine, Andre - CANADIAN FOOD INSPCTN AG Orourke, Katherine Spraker, Terry - COLORADO ST UNIV

Submitted to: Canadian Journal of Veterinary Research Publication Type: Peer Reviewed Journal Publication Acceptance Date: December 1, 2008 Publication Date: N/A

Interpretive Summary: Farmed cervids may be exposed to the prion disorder chronic wasting disease through contact with free ranging or farmed infected Rocky Mountain elk, white tailed deer, mule deer, or moose. This is the first report of experimental transmission of chronic wasting disease to red deer, an economically important agricultural commodity in parts of North America. Brain tissue from infected Rocky Mountain elk was administered by the oral route of red deer. Deer were examined at 18 months after infection for evidence of abnormal prion protein, the marker for the disease. The abnormal protein was found throughout the brain, spinal cord and lymphoid tissues, with variable distribution in other organ systems. This finding confirms the potential susceptibility of this species to disease under natural conditions and the reliability of the current testing format for identifying the abnormal protein in the tissues routinely collected in surveillance programs. The widespread distribution of the abnormal protein in red deer indicates the potential for shedding of the agent into the environment. Technical Abstract: Chronic wasting disease CWD is the transmissible spongiform encephalopathy or prion disease of wild and farmed cervid ruminants, including Rocky Mountain elk (Cervus elaphus nelsoni), white tailed deer (Odocoileus virginianus), mule deer (Odocoileus hemionus), or moose (Alces alces). Reliable data on the susceptibility of other farmed cervid species, the distribution of the abnormal prion protein marker in brain and lymphoid tissues collected in surveillance programs, and the role of prion genotype are necessary for design of control programs for CWD in farmed cervids. In this study, red deer (Cervus elaphus elaphus) were exposed to the prion agent by oral administration of brain homogenates from infected Rocky Mountain elk. Antemortem testing was performed at 7 months post infection and the deer were euthanized when clinical disease was observed at approximately 18 months after infection. The abnormal prion protein was assayed by immunohistochemistry, enzyme linked immunosorbent assay and western blot. Abnormal prion protein was found in the spinal cord, brainstem, cerebellum, midbrain, thalamus, and cerebrum in all 4 infected red deer. Most of the lymph nodes throughout the body were positive for abnormal prion proteins. Abnromal prion protein was observed in some additional peripheral tissues in some but not all of the deer. In particular, most areas of the gastrointestinal tract were positive for abnormal prions, although the salivary glands were rarely positive. This study demonstrates the potential for oral transmission of chronic wasting disease to red deer and confirms the usefulness of the current testing methods for post mortem diagnosis of the disease in this species.

Oral transmission and early lymphoid tropism of chronic wasting disease PrPres in mule deer fawns (Odocoileus hemionus )

Christina J. Sigurdson1, Elizabeth S. Williams2, Michael W. Miller3, Terry R. Spraker1,4, Katherine I. O'Rourke5 and Edward A. Hoover1

Mule deer fawns (Odocoileus hemionus) were inoculated orally with a brain homogenate prepared from mule deer with naturally occurring chronic wasting disease (CWD), a prion-induced transmissible spongiform encephalopathy. Fawns were necropsied and examined for PrP res, the abnormal prion protein isoform, at 10, 42, 53, 77, 78 and 80 days post-inoculation (p.i.) using an immunohistochemistry assay modified to enhance sensitivity. PrPres was detected in alimentary-tract-associated lymphoid tissues (one or more of the following: retropharyngeal lymph node, tonsil, Peyer's patch and ileocaecal lymph node) as early as 42 days p.i. and in all fawns examined thereafter (53 to 80 days p.i.). No PrPres staining was detected in lymphoid tissue of three control fawns receiving a control brain inoculum, nor was PrPres detectable in neural tissue of any fawn. PrPres-specific staining was markedly enhanced by sequential tissue treatment with formic acid, proteinase K and hydrated autoclaving prior to immunohistochemical staining with monoclonal antibody F89/160.1.5. These results indicate that CWD PrP res can be detected in lymphoid tissues draining the alimentary tract within a few weeks after oral exposure to infectious prions and may reflect the initial pathway of CWD infection in deer. The rapid infection of deer fawns following exposure by the most plausible natural route is consistent with the efficient horizontal transmission of CWD in nature and enables accelerated studies of transmission and pathogenesis in the native species.


These results indicate that mule deer fawns develop detectable PrP res after oral exposure to an inoculum containing CWD prions. In the earliest post-exposure period, CWD PrPres was traced to the lymphoid tissues draining the oral and intestinal mucosa (i.e. the retropharyngeal lymph nodes, tonsil, ileal Peyer's patches and ileocaecal lymph nodes), which probably received the highest initial exposure to the inoculum. Hadlow et al. (1982) demonstrated scrapie agent in the tonsil, retropharyngeal and mesenteric lymph nodes, ileum and spleen in a 10-month-old naturally infected lamb by mouse bioassay. Eight of nine sheep had infectivity in the retropharyngeal lymph node. He concluded that the tissue distribution suggested primary infection via the gastrointestinal tract. The tissue distribution of PrPres in the early stages of infection in the fawns is strikingly similar to that seen in naturally infected sheep with scrapie. These findings support oral exposure as a natural route of CWD infection in deer and support oral inoculation as a reasonable exposure route for experimental studies of CWD.


see full text ;

Sunday, December 06, 2009

Detection of Sub-Clinical CWD Infection in Conventional Test-Negative Deer Long after Oral Exposure to Urine and Feces from CWD+ Deer

or, what about water from cwd-endemic areas in Colorado ?

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

T.A. Nichols,1,2 Bruce Pulford,1 A. Christy Wyckoff,1,2 Crystal Meyerett,1 Brady Michel,1 Kevin Gertig,3 Edward A. Hoover,1 Jean E. Jewell,4 Glenn C. Telling5 and Mark D. Zabel1,*

1Department of Microbiology, Immunology and Pathology; College of Veterinary Medicine and Biomedical Sciences; Colorado State University; Fort Collins, CO USA; 2National Wildlife Research Center; Wildlife Services; United States Department of Agriculture; Fort Collins, CO USA; 3Fort Collins Utilities; Fort Collins; CO USA; 4Department of Veterinary Sciences; Wyoming State Veterinary Laboratory; University of Wyoming; Laramie, WY USA; 5Department of Microbiology, Immunology, Molecular Genetics and Neurology; Sanders Brown Center on Aging; University of Kentucky; Lexington, KY USA Key words: prions, chronic wasting disease, water, environment, serial protein misfolding cyclic amplification Abbreviations: CWD, chronic wasting disease; sPMCA, serial protein misfolding cyclic amplification; PrPC, cellular prion protein; PrPSc, disease-related, misfolded murine PrP; PrPCWD, disease-related, misfolded cervid PrP; PrPRES, protease-resistant PrP; FCWTF, Fort Collins water treatment facility

Chronic wasting disease (CWD) is the only known transmissible spongiform encephalopathy affecting free-ranging wildlife. Although the exact mode of natural transmission remains unknown, substantial evidence suggests that prions can persist in the environment, implicating components thereof as potential prion reservoirs and transmission vehicles.1-4 CWD-positive animals may contribute to environmental prion load via decomposing carcasses and biological materials including saliva, blood, urine and feces.5-7 Sensitivity limitations of conventional assays hamper evaluation of environmental prion loads in soil and water. Here we show the ability of serial protein misfolding cyclic amplification (sPMCA) to amplify a 1.3 x 10-7 dilution of CWD-infected brain homogenate spiked into water samples, equivalent to approximately 5 x 107 protease resistant cervid prion protein (PrPCWD) monomers. We also detected PrPCWD in one of two environmental water samples from a CWD endemic area collected at a time of increased water runoff from melting winter snow pack, as well as in water samples obtained concurrently from the flocculation stage of water processing by the municipal water treatment facility. Bioassays indicated that the PrPCWD detected was below infectious levels. These data demonstrate detection of very low levels of PrPCWD in the environment by sPMCA and suggest persistence and accumulation of prions in the environment that may promote CWD transmission.


CWD has been endemic in the area for forty years, and it remains unclear how long prions can persist in the environment. If persistent for at least several years, CWD prions deposited into the environment from thousands of infected carcasses may accumulate on soil and vegetation such that it can be washed into surface water draining the basin during snowmelt or rainstorms. Symptomatic and asymptomatic positive animals can also contribute to environmental CWD load via biological materials such as saliva, blood, urine and feces.5-7,32,36,38 Deer and elk defecate approximately 900,000 kg of feces and urinate approximately 14 million liters of urine in the area immediately surrounding the Cache la Poudre river per year.39-42 Although urine and feces likely contain much lower prion loads than blood or saliva, the sheer amount of excreta may contribute significantly to overall environmental prion contamination. 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, October 14, 2009

Detection of protease-resistant cervid prion protein in water from a CWD-endemic area

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