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Old May 26th 2015, 10:21 AM   #1
 ToddM's Avatar
 
  May 2009
  Fulton, Michigan


It was just announced that a WILD deer has tested positive for CWD in Michigan.* Ingham County, the same county as our states capitol is where it was found.* Who will all the radicals have to blame on this one?* Michigan residents will be saddened that they cant blame deer farmers this time. *


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Old May 26th 2015, 10:55 AM   #2
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  May 2009
  Fulton, Michigan


http://www.michigan.gov/dnr/0,4570,7...5592--,00.html
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Old May 26th 2015, 12:22 PM   #3
 Wild Rivers Whitetails's Avatar
 
  Apr 2009
  Northeast Wisconsin

Cervid: Deer Farming
Just proves the theory that is everywhere, they just haven't found it yet.
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Old May 26th 2015, 01:12 PM   #4
 
  Feb 2011
  Pierre SD


I figured they wouldn't even look for it until it was found behind a fence first so they would have someone to blame. How long will it take before a "tainted CWD" sample from a deer farm shows up positive?? Id be keeping a DNA sample if I*owned any deer near by and sent them off to be tested. When other countrys find out that CWD, a prion disease can be absorbed into our plants and crops and spread back, it ain't gonna be good for the wild deer and elk. Look at what one BSE cow did to the cattle trade with Japan, it cost us billions in sales over years, not because it was really an issue but because they will use it as an excuse to ruin our markets to benefit them. They will "fear" it could jump species and infect humans or their animals. Farmers aren't going to tolerate deer*eating all the free crops*they wants along with wrecking the markets for all the foreign markets we need to survive.*
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Old May 26th 2015, 02:56 PM   #5
 
  Dec 2010
  Sydney, Australia
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*When other countrys find out that CWD, a prion disease can be absorbed into our plants and crops and spread back, it ain't gonna be good for the wild deer and elk.*




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Have you any more on this? There is no doubt that prions can remain in soil for at least 2 decades (Iceland), but prions "absorbed into our crops & plants and spread back" is a new one to me.


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You need to be very careful with statements like this, as it can undermine the credibility of everything else you say & do, if it is found to be false.


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If you're worried about "species jump" look no further than scrapie. Was this not the origin of CWD?*


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I see so much misinformation on prion disease from both sides of the fence (pardon the pun). It appears to an outsider that everyone is expending most of their energy trying to shed the blame to every other stakeholder, instead of on the abatement of this disease. IMO it really is a case of letting any of the stakeholders who haven't sinned "cast the first stone". As I see it researchers, various wildlife agencies, deer hunters, taxidermists, urine products, deer breeders, etc, etc, all carrying some responsibility for spreading this disease. Why can't folks there spend halve the resources on stopping this disease instead of trying to prosecute each other?


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Is anyone actually thinking about the deer?


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Sharkey
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Old May 26th 2015, 04:20 PM   #6
 Four Seasons Whitetails's Avatar
 
  Oct 2009
  upstate ny

Cervid: Whitetail Deer
When other countries say they will no longer take our products because of CWD the CWD will disappear faster the Ebolla or whatever that crap was? Mark my words!
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Old May 26th 2015, 04:26 PM   #7
 
  Dec 2010
  Sydney, Australia


Why then do you still call it CWD & allow those against you to dictate the game by the use of their own terms? Shouldn't it just have been described as "a variant of scrapie" from the start? This would have avoided all the undue demonisation of deer folk.*


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Why aren't you just calling this disease scrapie?


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Sharkey
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Old May 26th 2015, 04:33 PM   #8
 
  Dec 2010
  Sydney, Australia
Four Seasons Whitetails1025661432686047



When other countries say they will no longer take our products because of CWD the CWD will disappear faster the Ebolla or whatever that crap was? Mark my words!




*I like many others stopped buying any beef products from the US after that last positive for BSE turned up in a dairy herd in California a couple of years ago. I was amazed at the lack of testing & governance around prion disease there. The US needs to take a good look at how the UK handled BSE & "mad cow" if it wants to maintain its overseas markets.*


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Scrapie (CWD) is now in South Korea as a direct result of importing live elk from North America.*


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Sharkey
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Old May 26th 2015, 05:11 PM   #9
 
  Feb 2011
  Pierre SD


Sharkey, you can google the phrase "can cwd spread from plants to wildlife". There is several stories about a study that came out last week that confirms the prions taken into plants can spread into animals. This pretty well confirms what the deer farmers have been saying all along about it popping up in places other then where its not*known to be and*not only spread by the deer farmers movements. If you've read about the cases and outbreaks of Scrapie over the years along with*CWD,*the maps line up amazingly well.***
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Old May 26th 2015, 05:47 PM   #10
 
  Dec 2010
  Sydney, Australia
sdbigbucks1025721432689113



Sharkey, you can google the phrase "can cwd spread from plants to wildlife". There is several stories about a study that came out last week that confirms the prions taken into plants can spread into animals. This pretty well confirms what the deer farmers have been saying all along about it popping up in places other then where its not*known to be and*not only spread by the deer farmers movements. If you've read about the cases and outbreaks of Scrapie over the years along with*CWD,*the maps line up amazingly well.***




Cheers mate. I googled that & all that came up was the two year old abstract which showed that plants can take up prions & that this "may" be a route of infection. Then a bit from NADEFA this week quoting that same article & also quoting "may". Its been two years now & silence? There has been no further qualifications on this. Its a very scary thought *to think it might be the case.*


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Any more info would be great.


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Sharkey
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Old May 26th 2015, 06:41 PM   #11
 Bell's Avatar
 
  Apr 2014
  Greensburg, IN
http://transmissiblespongiformenceph...e-and.html?m=1

Less than a fraction of 1% of the uncontrolled deer herd is tested for CWD. Most states have CWD positive herds. They simply don't test a high enough % of the herd to find it. CWD has been classified by APHIS as a low infectious disease. Folks in Michigan will continue to hunt. I would be much more concerned about the bovine TB positive deer in Michigan than a CWD positive animal. TB is zoonotic and classified as a contagious disease. It will be interesting to see how Chad Stewart handles this. I hope he takes a page from Wisconsin's more passive approach to management of the syndrome. It will be a shame if he follows the idiotic and wasteful approach of David Clausen. Michigan DNR director Kieth Creagh has already spoken boldly about eradicating the disease. It will be sad for hunters in Michigan if that is attempted. CWD can be managed. It is never eradicated.
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Old May 27th 2015, 03:37 AM   #12
 
  Nov 2010
  Lanesboro, Minnesota

COULD PLANTS SPREAD CWD TO ANIMAL LIFE?
(34,18,13); ;background-(226,221,199)



font-style:italic05/26/2015*
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“It is highly unlikely that CWD will spread naturally to the greater Yellowstone area from the endemic area [in southeast Wyoming].”


—Letter written by the late state wildlife veterinarian Tom Thorne, then acting director of the Wyoming Game and Fish Department, to conservationists on May 28, 2002.


How long before the deadly brain disorder chronic wasting disease — the deer family equivalent of mad cow disease — reaches the wildlife-rich heart of the greater Yellowstone ecosystem, home to some of the most famous ungulate herds in the world?


Hindsight can be 20/20. Contrary to what the late Tom Thorne claimed 13 years ago, CWD-infected wildlife is showing up in western Wyoming hunting units.


Each year afflicted animals come closer to Wyoming’s 22 elk feedgrounds and the U.S. Fish and Wildlife Service’s National Elk Refuge in Jackson Hole. Will western Wyoming soon become a springboard for CWD proliferating into Montana and Idaho?


Now scientific research into possible vectors of CWD transmission suggests a number of previously unrecognized routes for wildlife infection.


Texas study and another from the U.S. Geological Survey in Wisconsin indicate that not only can CWD prions be absorbed into plants, but they potentially can infect mammals grazing on them.


Earlier studies confirmed that CWD-infected animals can contaminate soils where they live with prions shed into the environment via fecal matter, bodily fluids and decomposing tissue. In fact, captive Wyoming elk kept in a state research pen where other wapiti died from CWD also contracted the disease and perished after being exposed merely to tainted soil.


Where speculation becomes hair-raising, especially when considering how prion diseases could jump species barriers and pose a threat to humans, is in the variety of plants found by scientists that can absorb prions.


“Grass plants can bind, uptake and transport infectious prions,” Dr. Claudio Soto and colleagues at UT Health in Houston revealed recently in the journal Cell Reports.


“This suggests that plants may play an important role in environmental prion contamination and the horizontal transmission of the disease,” Soto and researchers wrote.


Chronic wasting, known to strike deer, elk and moose in 22 states, is among a family of incurable diseases classified as “transmissible spongiform encephalopathies.” The list includes Mad Cow in cattle, variant Creutzfeldt-Jakob in humans and scrapie in sheep.


The diseases attack the brains of victims and render them incapacitated.


“There is no proof of [CWD] transmission from wild animals and plants to humans,” Soto wrote. “But it’s a possibility that needs to be explored and people need to be aware of it. Prions have a long incubation period.”


A study led by Christopher Johnson at the USGS lab in Madison, Wisconsin, demonstrated that plants growing from CWD-contaminated soils could spread the disease.


Johnson discovered that prions could be absorbed into alfalfa, barley, tomatoes and corn. In turn, when CWD prions were extracted from plants and injected into mice, the rodents became ill.


“Our results suggest that prions are taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to CWD and scrapie agents,” Johnson wrote in a 2013 abstract.


That comes on top of other insights, one being that hard-to-destroy prions bind with soil and can become up to 680 times more infectious when ingested orally.


Lloyd Dorsey, conservation director for the Sierra Club’s Wyoming Chapter, has been doggedly tracking CWD in Wyoming for two decades.


Dorsey asks: What if CWD reaches thousands of elk bunched together on winter feedgrounds and it then becomes established in grasses and soils?


He believes that by continually downplaying warnings, state and federal agencies are unprepared to deal with the consequences of unnaturally congregating wildlife herds in winter that then disperse throughout the northern Rockies in summer.


Wyoming, Dorsey notes, has more CWD cases in elk and deer and more land affected and at risk from the disease than any other state in the country. Apart from animal-to-animal transmission, the Texas and Wisconsin studies show just how insidious the possible avenues for spreading CWD might be.


“Denial never serves the public’s interest,” Dorsey says. “We should be in an action mode to mitigate the effects of this potentially catastrophic disease we know is coming.”


Source: Todd Wilkinson, Jackson Hole News & Guide






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Old May 27th 2015, 04:13 AM   #13
 
  Dec 2010
  Sydney, Australia
G O Whitetails1025861432726670



COULD PLANTS SPREAD CWD TO ANIMAL LIFE?
(34,18,13); ;background-(226,221,199)



font-style:italic05/26/2015*
margin:0px 15px 15px 0px









“It is highly unlikely that CWD will spread naturally to the greater Yellowstone area from the endemic area [in southeast Wyoming].”


—Letter written by the late state wildlife veterinarian Tom Thorne, then acting director of the Wyoming Game and Fish Department, to conservationists on May 28, 2002.


How long before the deadly brain disorder chronic wasting disease — the deer family equivalent of mad cow disease — reaches the wildlife-rich heart of the greater Yellowstone ecosystem, home to some of the most famous ungulate herds in the world?


Hindsight can be 20/20. Contrary to what the late Tom Thorne claimed 13 years ago, CWD-infected wildlife is showing up in western Wyoming hunting units.


Each year afflicted animals come closer to Wyoming’s 22 elk feedgrounds and the U.S. Fish and Wildlife Service’s National Elk Refuge in Jackson Hole. Will western Wyoming soon become a springboard for CWD proliferating into Montana and Idaho?


Now scientific research into possible vectors of CWD transmission suggests a number of previously unrecognized routes for wildlife infection.


Texas study and another from the U.S. Geological Survey in Wisconsin indicate that not only can CWD prions be absorbed into plants, but they potentially can infect mammals grazing on them.


Earlier studies confirmed that CWD-infected animals can contaminate soils where they live with prions shed into the environment via fecal matter, bodily fluids and decomposing tissue. In fact, captive Wyoming elk kept in a state research pen where other wapiti died from CWD also contracted the disease and perished after being exposed merely to tainted soil.


Where speculation becomes hair-raising, especially when considering how prion diseases could jump species barriers and pose a threat to humans, is in the variety of plants found by scientists that can absorb prions.


“Grass plants can bind, uptake and transport infectious prions,” Dr. Claudio Soto and colleagues at UT Health in Houston revealed recently in the journal Cell Reports.


“This suggests that plants may play an important role in environmental prion contamination and the horizontal transmission of the disease,” Soto and researchers wrote.


Chronic wasting, known to strike deer, elk and moose in 22 states, is among a family of incurable diseases classified as “transmissible spongiform encephalopathies.” The list includes Mad Cow in cattle, variant Creutzfeldt-Jakob in humans and scrapie in sheep.


The diseases attack the brains of victims and render them incapacitated.


“There is no proof of [CWD] transmission from wild animals and plants to humans,” Soto wrote. “But it’s a possibility that needs to be explored and people need to be aware of it. Prions have a long incubation period.”


A study led by Christopher Johnson at the USGS lab in Madison, Wisconsin, demonstrated that plants growing from CWD-contaminated soils could spread the disease.


Johnson discovered that prions could be absorbed into alfalfa, barley, tomatoes and corn. In turn, when CWD prions were extracted from plants and injected into mice, the rodents became ill.


“Our results suggest that prions are taken up by plants and that contaminated plants may represent a previously unrecognized risk of human, domestic species and wildlife exposure to CWD and scrapie agents,” Johnson wrote in a 2013 abstract.


That comes on top of other insights, one being that hard-to-destroy prions bind with soil and can become up to 680 times more infectious when ingested orally.


Lloyd Dorsey, conservation director for the Sierra Club’s Wyoming Chapter, has been doggedly tracking CWD in Wyoming for two decades.


Dorsey asks: What if CWD reaches thousands of elk bunched together on winter feedgrounds and it then becomes established in grasses and soils?


He believes that by continually downplaying warnings, state and federal agencies are unprepared to deal with the consequences of unnaturally congregating wildlife herds in winter that then disperse throughout the northern Rockies in summer.


Wyoming, Dorsey notes, has more CWD cases in elk and deer and more land affected and at risk from the disease than any other state in the country. Apart from animal-to-animal transmission, the Texas and Wisconsin studies show just how insidious the possible avenues for spreading CWD might be.


“Denial never serves the public’s interest,” Dorsey says. “We should be in an action mode to mitigate the effects of this potentially catastrophic disease we know is coming.”


Source: Todd Wilkinson, Jackson Hole News & Guide









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It's very concerning, however the abstract that this relies upon is now over 2 years old & we haven't see any further qualifications. Look at the use of words like "potentially", "may", "could" *& "suggest". *I'm not saying its not correct, but at first look Its pretty soft, especially after 2 years without more insight. I wouldn't be risking any credibility on this ATM.


*


Any more info would be great.


*


Sharkey
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Old May 27th 2015, 05:58 AM   #14
 Bell's Avatar
 
  Apr 2014
  Greensburg, IN
Sharkey

This is a lot more info that is again abstract. The word "likely" isn't very scientific.

I don't think that anyone knows at what point a miss folded prion is shed by a living host.


This info was edited from a blog run by Terry Singletary.


Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions

DOI: http://dx.doi.org/10.1016/j.celrep.2015.04.036


•Grass plants bind prions from contaminated brain and excreta •Prions from different strains and species remain bound to living plants •Hamsters fed with prion-contaminated plant samples develop prion disease •Stems and leaves from grass plants grown in infected soil contain prions.


Summary


Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrPSc for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease.


This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).


Received: October 31, 2014; Received in revised form: February 4, 2015; Accepted: April 15, 2015; Published Online: May 14, 2015


2015 The Authors. Published by Elsevier Inc.

http://www.cell.com/cell-reports/abstract/S2211-1247(15)00437-4



Prions Bind to Plants and Bound-PrPSc Efficiently Sustain Prion Replication


To study whether plants can interact with prions, we exposed wheat grass roots and leaves to brain homogenate from hamsters that have succumbed to prion disease induced by experimental inoculation with the 263K prion strain. The presence of PrPSc and infectivity attached to the plants was studied in vitro using the protein misfolding cyclic amplification (PMCA) technique and in vivo by infectivity bioassays. For in vitro analyses, the plant tissues (roots and leaves) were incubated for 16 hr with serial dilutions of 263K-brain homogenate ranging from 10 1 to 10 8. Roots and leaves were washed thoroughly and analyzed for the presence of PrPSc by serial PMCA (Morales et al., 2012). The results show that even highly diluted PrPSc can bind to roots and leaves and sustain PrPC conversion (Figure 1A). Although a direct comparison cannot be made, because of differences on the effective surface, roots appear to retain PrPSc better than leaves. However, both roots and leaves capture PrPSc efficiently, even at very small concentrations, equivalent to those present in biological fluids, such as blood and urine (Chen et al., 2010). By comparing the detection of PrPSc-bound to plants (Figure 1A) with an experiment in which the same dilutions of 263K brain homogenate were added directly to the tubes containing normal brain homogenate and an equivalent piece of leaves or roots (Figure 1, we can estimate that a high proportion of PrPSc present in the sample was attached to the plant tissue. Importantly, no detection of PrPSc was observed when leaves and roots were exposed to normal brain homogenate (Figure 1C). However, comparing PMCA amplification in the presence (Figure 1 or in the absence (Figure S1A) of plant tissue, it is possible to appreciate that plants (both leaves and roots) partially inhibits the PMCA reaction. This explains why in most of the experiments with plants, protease-resistant PrPSc is only observed after two rounds of PMCA. In our current PMCA settings, no false-positive PrPSc signals were ever detectable when samples did not contain PrPSc inoculum (Figure S1. These results indicate that leaves and roots can efficiently bind PrPSc, which remains able to catalyze PrPC to PrPSc conversion, leading to prion replication. In these experiments, plant tissues were incubated with prions for 16 hr, but a similar experiment in which roots and leaves were exposed to a 10 5 dilution of 263K brain homogenate for different times, we found that as little as 2 min of incubation was sufficient for the efficient contamination of plants (Figure S2).

Animals Can Be Infected by Oral Administration of Prion-Contaminated Plants



To investigate whether prion-contaminated plants were able to infect animals by ingestion, leaves and roots previously incubated with either 263K-infected or control hamster brain homogenates were orally administered into naive hamsters. After exposure, plants were extensively washed five times with water and animals were fed with dried material. As positive controls, we orally administered 750 ml of 5% 263K brain homogenate (same material used to contaminate plant tissue). All animals that ingested prion contaminated leaves and roots developed typical prion disease. Although the incubation times were significantly longer in animals ingesting prions attached to leaves and roots as compared with those fed directly with the brain material, the differences were not as high as one could have expected (Figure 2A). Indeed, incubation periods were 147 10,



159 10, and 164 13 days (mean SEM) for the groups inoculated with brain homogenate, and prion contaminated roots and leaves, respectively. Prion disease was confirmed by histological study of PrPSc deposition, astrogliosis, and brain vacuolation (Figure 2, as well as by biochemical detection of protease-resistant PrPSc by western blot (Figure 2C). None of the animals inoculated with leaves and roots exposed to normal brain homogenate developed disease up to 550 days post-inoculation. Histological analysis did not show any PrPSc staining or disease specific alteration in control animals.



Plants Bind Prions from Different Strains and Species To analyze prion-plant interaction with other species and strains of the prion agent, we performed similar studies as described in Figure 1, by incubating leaves and roots with a preparation containing hamster, murine, cervid, and human prions corresponding to the Hyper, 301C, CWD, and vCJD prion strains, respectively. PrPSc from these strains and species showed good amplification by PMCA, using homologous substrates (Figure S3A). In all cases, leaves and roots bound prions from these species and retained the ability to replicate in vitro (Figure S3, indicating that the interaction of PrPSc with plants is a general feature of infectious prions.


Contamination of Plants with Prions Excreted in Urine and Feces


Under natural conditions, it is likely that the main source of prions in the environment comes from secretory and excretory fluids, such as saliva, urine, and feces. We and others have shown that PrPSc is released in these fluids and excretions in various animal species (Gonzalez-Romero et al., 2008; Haley et al., 2009, 2011; Maddison et al., 2010; Terry et al., 2011; Moda et al., 2014). It has been estimated that the amount of infectious prions spread by excreta during the animals’ lifespan could match or even surpass the quantity present in the brain of a symptomatic individual (Tamgu ney et al., 2009). To study whether plant tissue can be contaminated by waste products excreted from prion-infected hamsters and deer, leaves and roots were incubated with samples of urine and feces and the presence of PrPSc analyzed by serial rounds of PMCA. For these experiments, plant tissues were incubated for 1 hr with urine or feces homogenates obtained either from 263K-infected hamsters or CWD-affected cervids. This time was chosen because longer incubation with these biological fluids affected the integrity of the plant tissue. After being thoroughly washed and dried, PrPSc attached to leaves and roots was detected by PMCA. The results clearly show that PrPSc was readily detectable after three or four rounds of PMCA in samples of wheat grass leaves and roots exposed to both urine and feces from 263K sick hamsters (Figure 3A) and CWD-affected cervids (Figure 3. Comparing these results with studies of the direct detection of PrPSc in urine and feces (Figures 3A and 3, it seems that the majority of PrPSc present in these waste products was effectively attached to leaves and roots. No signal was observed in plant tissue exposed to urine or feces coming from non-infected hamsters.

To investigate a more natural scenario for prion contamination of living plants, we sprayed the leaves of wheat grass with a preparation containing 1% 263K hamster brain homogenate. Plants were let to grow for different times after exposure, and PrPSc was detected in the leaves by PMCA in duplicates for each time point. The results show that PrPSc was able to bind to leaves and remained attached to the living plants for at least 49 days after exposure (Figure 4). Considering that PrPSc signal was detectable normally in the second or third round of PMCA without obvious trend in relation to time, we conclude that the relative amount of PrPSc present in leaves did not appear to change substantially over time. These data indicate that PrPSc can be retained in living plants for at least several weeks after a simple contact with prion contaminated materials, and PrPSc remains competent to drive prion replication.


Plants Uptake Prions from Contaminated Soil


The experiments described above were done by exposure of the surface of leaves and roots with different solutions containing prions. To evaluate whether living plants can uptake PrPSc from contaminated soil, we grew barley grass plants on soil that was contaminated by addition of 263K brain homogenate. Plants were grown for 1 or 3 weeks under conditions that carefully prevented any direct contact of the aerial part of the plant with the soil. After this time, pieces of stem and leaves were collected and analyzed for the presence of PrPSc by PMCA. As shown in Figure 5A, all plants grown for 3 weeks in contaminated soil contained PrPSc in their stem, albeit in small quantities that required four serial rounds of PMCA for detection. One of the four plants analyzed contained a detectable amount of PrPSc in the leaves (Figure 5, indicating that prions were uptaken from the soil and transported into the aerial parts of the plants, far from the soil. These results differ from a recent article reporting that infectious prions were not detectable in above the ground tissues of wheat plants exposed to CWD prions (Rasmussen et al., 2014). The lack of detection in this article is most likely due to the low sensitive techniques (western blots or ELISA) employed to analyze the presence of PrPSc. Indeed, as we reported previously, PMCA has a power of detection, which is several millions times higher than western blots or ELISA (Saa et al., 2006). In order to estimate the amount of PrPSc present in stem and leaves coming from contaminated soil, we performed a quantitative PMCA study, as previously described (Chen et al., 2010). Unfortunately, by comparing the PMCA amplification in the absence or the presence of plant tissue, it is possible to conclude that stems and leaves substantially interfered with the PMCA procedure, and thus the calculation cannot be very precise (Figure S4). Indeed, after two rounds of PMCA we cannot detect any protease-resistant PrPSc, but on the third round we observed the maximum amplification (10 9), presumably because at this round the concentration of PMCA inhibitors has been reduced enough to permit good amplification. At this point, we can estimate that the amount of PrPSc that reaches the stem and leaves from contaminated soil is equivalent to the PrPSc concentration present in a 10 6 to 10 9 dilution of sick brain homogenate. Nevertheless, this result is interesting, because it indicates that the amount of prions uptaken from soil and transported to aerial parts of the plant is within the infectious range. Indeed, titration studies showed that the last infectious dilution of a 263K brain homogenate is 10 9 (Gregori et al., 2006).


This study shows that plants can efficiently bind prions contained in brain extracts from diverse prion infected animals, including CWD-affected cervids. PrPSc attached to leaves and roots from wheat grass plants remains capable of seeding prion replication in vitro. Surprisingly, the small quantity of PrPSc naturally excreted in urine and feces from sick hamster or cervids was enough to efficiently contaminate plant tissue. Indeed, our results suggest that the majority of excreted PrPSc is efficiently captured by plants’ leaves and roots. Moreover, leaves can be contaminated by spraying them with a prion-containing extract, and PrPSc remains detectable in living plants for as long as the study wasperformed (several weeks). Remarkably, prion contaminated plants transmit prion disease to animals upon ingestion, producing a 100% attack rate and incubation periods not substantially longer than direct oral administration of sick brain homogenates. Finally, an unexpected but exciting result was that plants were able to uptake prions from contaminated soil and transport them to aerial parts of the plant tissue. Although it may seem farfetched that plants can uptake proteins from the soil and transport it to the parts above the ground, there are already published reports of this phenomenon (McLaren et al., 1960; Jensen and McLaren, 1960; Paungfoo-Lonhienne et al., 2008). The high resistance of prions to degradation and their ability to efficiently cross biological barriers may play a role in this process. The mechanism by which plants bind, retain, uptake, and transport prions is unknown. Weare currently studying the way in which prions interact with plants using purified, radioactively labeled PrPSc to determine specificity of the interaction, association constant, reversibility, saturation, movement, etc.

Epidemiological studies have shown numerous instances of scrapie or CWD recurrence upon reintroduction of animals on pastures previously exposed to prion-infected animals. Indeed, reappearance of scrapie has been documented following fallow periods of up to 16 years (Georgsson et al., 2006), and pastures were shown to retain infectious CWD prions for at least 2 years after exposure (Miller et al., 2004). It is likely that the environmentally mediated transmission of prion diseases depends upon the interaction of prions with diverse elements, including soil, water, environmental surfaces, various invertebrate animals, and plants. However, since plants are such an important component of the environment and also a major source of food for many animal species, including humans, our results may have far-reaching implications for animal and human health. Currently, the perception of the risk for animal-to-humanprion transmissionhas beenmostly limited to consumption or exposure to contaminated meat; our results indicate that plants might also be an important vector of transmission that needs to be considered in risk assessment.

http://www.cell.com/cell-reports/pdf...15)00437-4.pdf


Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions

http://www.cell.com/cell-reports/pdf...247(15)00437-4


Friday, September 27, 2013


Uptake of Prions into Plants
http://chronic-wasting-disease.blogs...to-plants.html


Friday, May 15, 2015 Grass Plants Bind, Retain, Uptake, and Transport Infectious Prions


Report

http://transmissiblespongiformenceph...ptake-and.html
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Old May 27th 2015, 06:40 AM   #15
 
  Apr 2009
  IA / USA


Jonathan, I'm sorry but I am not interested in reading anything linked with Terry Singletary...
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