Wednesday, November 28, 2012

Scientific and technical assistance on the provisional results of the study on genetic resistance to Classical scrapie in goats in Cyprus 1

SCIENTIFIC REPORT OF EFSA


Scientific and technical assistance on the provisional results of the study on genetic resistance to Classical scrapie in goats in Cyprus1


European Food Safety Authority2, 3


European Food Safety Authority (EFSA), Parma, Italy


ABSTRACT


This EFSA Scientific Report reviews and discusses the provisional results of a study (EURL/Cypriot study) on genetic resistance to Classical scrapie in goats in Cyprus. It is concluded that the provisional results obtained in the study further support the lower susceptibility to Classical scrapie in goats carrying the D146 and S146 alleles compared to wild type (N146N) goats. The results from intracerebral challenge are not compatible with a level of resistance as high as the one observed in sheep carrying the ARR allele or in goats carrying the K222 allele. Final results from the oral challenge will be crucial in determining the level of resistance associated with the D146 and S146 alleles. Furthermore, it is concluded that the provisional results obtained in the study are compatible with the possibility to use the D146 and S146 alleles to build a genetic strategy to control and eradicate Classical scrapie in goats in Cyprus. However, the success of such a strategy will be determined by the level of resistance associated with the D146 and S146 alleles against infection with all the different TSE agents proved to be circulating in Cyprus, which at this stage of the EURL/Cypriot study remains to be definitively assessed. In addition, as compared to the results of the model developed in the study, it is concluded that the efficiency of the implementation in the field of a breeding strategy selecting for the D146 and S146 alleles may be lower due to potential practical constraints related to the management of genetic diversity, to the selection for production and health traits and to the need of moving animals for breeding purposes in Cyprus. Recommendations on aspects that may be considered when completing the study are formulated.


© European Food Safety Authority, 2012


KEY WORDS


TSE, Classical scrapie, goat, genetic resistance, breeding programme, Cyprus.


snip...


Interim Conclusions


The oral challenge studies, the management cull and the whole herd cull data all support the previously published field observations that on one side the genotype N146N is particularly associated with scrapie susceptibility and on the other side the genotypes N146D, N146S, D146D, D146S and S146S are associated with a degree of resistance.


All genotypes can succumb to challenge by the intracerebral route, but the resulting phenotype is different when comparing the animals carrying genotype N146N with all the others (most notably, no detection of PrPSc in the periphery of infected animals with all the non-N146N-genotypes).


It is important that the oral challenges are continued to endpoint to establish the relative resistance of other genotypes to challenge by this more natural route Appendix A to Scientific Report of EFSA, EFSA Journal 2012;10(11):2972


Cyprus/EURL resistance in goats protocol Report May 2012


Page 13 of 13


All components of the study reinforce previously published UK caprine data3 which indicates that the current ELISA rapid test screen has considerably lower sensitivity (approx 50%) than immunohistochemistry.


The wider issue of discriminatory testing for BSE vs scrapie may need to be reviewed (regardless of genotype), since data from these studies suggest that direct extrapolation from ovine data may not be appropriate for all caprine isolates.


The TSE European Union Reference Laboratory at the Animal Health and Veterinary Laboratory Agency New Haw, UK


The Government Veterinary Services, Cyprus


May 2012







Wednesday, January 18, 2012


BSE IN GOATS CAN BE MISTAKEN FOR SCRAPIE


February 1, 2012



posted January 18, 2012



BSE in goats can be mistaken for scrapie



Bovine spongiform encephalopathy in goats could be misdiagnosed as scrapie in the absence of appropriate discriminatory tests, and such misidentification occurred at least once before such tests were developed, according to a report released in December.



The article, "Isolation of prion with BSE properties from farmed goat" (Emerging Infectious Diseases 2011;17:2253-2261), indicates BSE can affect small ruminants under natural conditions and that the condition can be misdiagnosed. The agent that causes scrapie is not known to infect humans, but consumption of beef contaminated with the prions that cause BSE is connected with variant Creutzfeldt-Jakob disease, a neurodegenerative disorder in humans.



The report calls for continued extensive surveillance and breeding plans to prevent BSE outbreaks among small ruminants. Such outbreaks could harm public health.



The authors stated in the text that the misdiagnosis occurred in 1990 in the United Kingdom. The case had been identified as suspected BSE in 2006 because differential immunohistochemical analysis of fixed brain tissue produced a signature indistinguishable from BSE. The authors of the recent report used a bioassay to confirm the BSE diagnosis.



The sample collected in 1990 was among 26 historic samples collected from 1984-2002, the report states.



The report indicates the U.K. goat and a goat in France found to have BSE in 2005 both likely became infected through contaminated food supplements.



While BSE lesions are contained mainly within nervous tissue in cattle, the report states "in small ruminants the BSE agent is widely distributed in peripheral tissues and can be transmitted horizontally." Feed ban measures alone would be insufficient for controlling a BSE outbreak in small ruminants, according to the report.



"Also, it would be impossible to prevent BSE from entering the human food chain through consumption of food products derived from small ruminants," the report states.













Discussion




We confirmed that the agent responsible for TSE in a UK goat, which was initially reported as scrapie in 1990 and subsequently as suspected BSE in 2006 (16), was a BSE agent. This conclusion was based on bioassay of nervous tissue in mice demonstrating similarities of histopathologic lesions, PrPSc mapping in the brain, and WB of PrPSc with those of mice inoculated with BSE from various ovine, caprine, and bovine sources.











Saturday, December 3, 2011




Isolation of Prion with BSE Properties from Farmed Goat Volume 17, Number




12—December 2011









snip...see full text ;








Scientific Opinion on genetic TSE resistance in goats in all European Union Member States Question number: EFSA-Q-2009-00448


Adopted: 21 October 2009 Summary (0.1Mb)


Opinion (0.3Mb)


Summary


Following a request from the European Commission, the Panel on Biological Hazards (BIOHAZ) was asked to deliver a scientific opinion on genetic resistance to Transmissible Spongiform Encephalopathies (TSE) in goats.


For a first part of that request, the BIOHAZ Panel adopted on 5th March 2009 a scientific opinion on the scientific validity of a study carried out by the Cypriot authorities under the auspices of the Community Reference Laboratory (CRL) for TSEs. That scientific opinion also indicated to what extent the information contained in the study could be used as relevant tools to control Classical scrapie in Cyprus.


In the current scientific opinion the BIOHAZ Panel addresses genetic resistance as a relevant tool for breeding for resistance to all TSEs of goats (including Atypical scrapie and BSE) in all the Member States (MSs) (except for Classical scrapie in Cyprus).


To carry out this task, available scientific knowledge on genetic TSE resistance in goats in the EU is reviewed, addressing those PRNP polymorphisms for which a capacity to provide resistance to TSEs in goats has been (or is being) investigated. Details tailored to the different TSEs found in this small ruminants (i.e. Classical scrapie, Atypical scrapie and BSE) are also considered and presented.


Further on, the feasibility of a large-scale breeding program in animal populations would need to be supported by a sound logistical and technical infrastructure in any given territory. In order to collect preliminary data that could help to evaluate the specific situation in the different EU MSs, a questionnaire was developed and circulated among the EFSA BSE-TSE Network. The results of the analysis of the replies received are also presented herewith.


The BIOHAZ Panel concluded that there are encouraging but as yet incomplete data to consider supporting a breeding programme for resistance in goats against Classical scrapie in all EU MSs, and ongoing studies are expected to provide a more robust scientific background in the coming years. On the other hand, at this moment there are not enough data available to consider supporting a breeding programme for resistance against Atypical scrapie and BSE in goats in all EU MSs. Experiments are ongoing on BSE in goats and results will be available in the next years. Furthermore, there are limited data suggesting that an allele (H154) might confer resistance to Classical scrapie but increase susceptibility to Atypical scrapie.


The frequency of the wild type allele, which is known to confer susceptibility to Classical scrapie, is high in all goat breeds considered. Thus, selection for putative resistance alleles will be slow, complicated and highly dependent on breeding structure.


It is acknowledged that any large scale breeding programme for TSE resistance in goats must take into consideration key elements related to the current dissemination of potentially TSE protective polymorphisms in the goat population of each EU MS and the characterisation of the real protection provided by those polymorphisms. At present, only a few EU MSs seem to have in place the necessary elements to introduce a breeding for resistance programme for Classical scrapie in goats.


The BIOHAZ Panel makes a series of recommendations on new investigations in order to assess the efficacy of breeding for the candidate PRNP alleles as a mean to control TSEs in goats. Furthermore, research on the possible adverse effects of the candidate PRNP polymorphisms on other production traits should be encouraged. In addition, it is recommended that a breeding for resistance programme for TSE in goats is first implemented in the seven EU MSs with the largest goat population as this would have the most impact.


Published: 9 November 2009







OPINION








Tuesday, November 10, 2009


A retrospective immunohistochemical study reveals atypical scrapie has existed in the United Kingdom since at least 1987


Brief Research Reports








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


Subject: Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004


Date: Wed, 19 Jan 2005 13:30:26 –0600


From: "Terry S. Singeltary Sr."


To: Bovine Spongiform Encephalopathy


CC: cjdvoice@yahoogroups.com


Wednesday January 19, 2005


Brain disease in Greek goats


Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004, EU figures made public yesterday reveal.


The data, issued by the European Food Safety Authority (EFSA), show that 12 cases of transmissible spongiform encephalopathies (TSE) were discovered in Greece, eight in Cyprus and 26 in France out of some 17,294 goats tested throughout the EU in 2004. The figures were made public by Left Coalition Synaspismos MEP Dimitris Papadopoulos.


Some 100 Europeans have died from the human form of bovine spongiform encephalopathy (BSE), or mad cow disease, a strain of the TSE group. Meanwhile, tests are continuing in the case of a French goat slaughtered in 2002, which experts think may have developed BSE. The EU bans the use of milk and meat from herds affected by a TSE case.









TSS





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


Subject: Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004


Date: Wed, 19 Jan 2005 13:30:26 –0600


From: "Terry S. Singeltary Sr."


To: Bovine Spongiform Encephalopathy


CC: cjdvoice@yahoogroups.com


Wednesday January 19, 2005


Brain disease in Greek goats


Twelve Greek goats were found to be suffering from the brain-wasting disease scrapie in the first half of 2004, EU figures made public yesterday reveal.


The data, issued by the European Food Safety Authority (EFSA), show that 12 cases of transmissible spongiform encephalopathies (TSE) were discovered in Greece, eight in Cyprus and 26 in France out of some 17,294 goats tested throughout the EU in 2004. The figures were made public by Left Coalition Synaspismos MEP Dimitris Papadopoulos.


Some 100 Europeans have died from the human form of bovine spongiform encephalopathy (BSE), or mad cow disease, a strain of the TSE group. Meanwhile, tests are continuing in the case of a French goat slaughtered in 2002, which experts think may have developed BSE. The EU bans the use of milk and meat from herds affected by a TSE case.










TSS





Comment from Terry S Singeltary, CJD WATCH/VOICE




Document ID: APHIS-2007-0033-0002 Document Type: Public Submission
This is comment on Proposed Rule: Agricultural Bioterrorism Protection Act of 2002; Biennial Review and Republication of the Select Agent and Toxin List
Docket ID:
APHIS-2007-0033
 RIN:0579-AC53

Topics: No Topics associated with this document

View Document:





snip...



Under APHIS-PPQ’s agriculture quarantine inspection monitoring, 584 air passengers from Greece were sampled for items of agricultural interest in fiscal year 2000. Of these passengers, 14 carried meat (non-pork) items that could potentially transmit pathogens that cause BSE; most passengers carried from one to two kilograms (kg) of meat, although one passenger in November 1999 carried 23 kg of meat in a suitcase. Florida, Massachusetts, and New York were the reported destinations of these passengers. None of the passengers with meat items reported plans to visit or work on a ranch or farm while in the US.





Source: US Department of Transportation, and APHIS-PPQ Agricultural Quarantine Inspection data base

















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Monday, November 19, 2012

Prion in Saliva of Bovine Spongiform Encephalopathy–Infected Cattle

Letter



Prion in Saliva of Bovine Spongiform Encephalopathy–Infected Cattle



To the Editor: A definitive diagnosis of bovine spongiform encephalopathy (BSE) in cattle usually relies on Western blot and immunohistochemical testing of samples from the obex region of the brainstem. These conventional diagnostic tests can detect the presence of the abnormal (disease-associated) form of the prion protein (PrPSc) in brain samples several months before the onset of clinical signs; however, there is no appropriate, universal tool for early preclinical and antemortem diagnosis of BSE. Furthermore, confirmation of the disease is currently only possible by postmortem examination of brain tissues. In this study, we used the serial protein misfolding cyclic amplification (sPMCA) technique to determine the presence of PrPSc in saliva samples collected from BSE-infected cows before and after the onset of disease (1). In a previous study (2), we analyzed the tissue distribution of PrPSc in cattle up to 66 months after they were orally inoculated with a relatively low dose (5 g) of homogenized brainstem from animals with naturally occurring BSE in England. In 2011, after publication of that study and 83.3 months after the cows were inoculated, clinical signs of BSE developed in 1 cow (no. 5444); necropsy was performed 84.7 months after inoculation. In addition, we used saliva samples from 2 BSE-affected cows (nos. 5413 and 5437) (2) to determine the presence of PrPSc. We collected saliva samples from animals at 4 monthly intervals, beginning in 2009, 56 months after inoculation. Samples were stored at −80°C until analysis. Using the sodium phosphotungstic acid precipitation method, we concentrated (100-fold) individual 1-mL saliva samples from each time point. We then diluted the concentrated samples 1:10 with the normal isoform of prion protein substrate containing 0.5% potassium dextran sulfate. Using the sPMCA technique as described (1), we amplified the samples in 3–8 tubes, and we used Western blot to analyze the proteinase K–treated sPMCA products (2). Using Western blot and immunohistochemical tests, we detected the accumulation of PrPSc in brains collected at necropsy from the 3 cows examined. In addition, using the sPMCA technique, we detected PrPSc signal in 1) saliva samples that were concentrated from samples collected from the same 3 cows at necropsy and in 2) concentrated saliva samples that were collected from 2 of the cows (nos. 5413 and 5444) at the early clinical stages of disease.




Figure



Figure. . Western blot detection, using the serial protein misfolding cyclic amplification technique, of the abnormal (disease-associated) form of the prion protein (PrPSc) in concentrated saliva samples from 3 cows experimentally infected...



After saliva samples underwent 3 rounds of amplification, we detected PrPSc in a saliva sample that was collected from cow number 5437 two months before the clinical onset of clinical symptoms (Figure). For 2 of the cows (nos. 5413 and 5437), the positive ratio of salivary PrPSc at round 4 of amplification increased as the disease progressed (Figure). Because PrPSc signal could be detected in BSE-infected brain homogenates diluted up to 10−10 after 2 rounds of amplification (1), we estimated PrPSc levels in the nonconcentrated original saliva samples to be lower than those in BSE-infected brain homogenate diluted to 10−12. No PrPSc signal was detected in samples collected from the 3 cows 3–5 months before the onset of clinical symptoms or from age-matched noninfected controls, even after 4 rounds of amplification. We demonstrated the presence of PrPSc in saliva of BSE-affected cows during the clinical stage of the disease, and in 1 case, at the preclinical or asymptomatic stage. Our findings suggest that PrPSc is likely to be detected in the saliva of BSE-affected cattle during the clinical stage of disease, after accumulation of PrPSc in the brain. PrPSc was found in the salivary glands of BSE-affected cattle at the terminal stage of infection (1). Therefore, once the infectious agent reaches the central nervous system, it may spread centrifugally from the brain to the salivary glands through the autonomic nervous system. Infectivity of saliva and the presence of PrPSc in saliva have been reported in other ruminants affected with transmissible spongiform encephalopathy. Infectivity of saliva was demonstrated in deer with chronic wasting disease (3) and in scrapie-affected sheep (4); the immunolabeled PrPSc accumulated in the salivary glands of scrapie-affected sheep (5). A low level of PrPSc was detected in concentrated buccal swab samples of preclinical scrapie-infected sheep by using sPMCA (6,7). These results suggest that small amounts of PrPSc may accumulate in the salivary glands and are then secreted into saliva. The presence of infectious prions in saliva may explain the facile horizontal transmission of scrapie in sheep (4–6) and chronic wasting disease in deer (4,8). There has been no epidemiologic evidence, however, that saliva, milk, blood, and cerebrospinal fluid from BSE-infected cattle are infectious (9). Nonetheless, the potential risk for BSE transmission by body fluids or excretions from BSE-infected cattle is cannot be ruled out by the current data.



Hiroyuki Okada, Yuichi Murayama , Noriko Shimozaki, Miyako Yoshioka, Kentaro Masujin, Morikazu Imamura, Yoshifumi Iwamaru, Yuichi Matsuura, Kohtaro Miyazawa, Shigeo Fukuda, Takashi Yokoyama, and Shirou Mohri



Author affiliations: Author affiliations: National Agriculture and Food Research Organization, Tsukuba, Japan (H. Okada, Y. Murayama, N. Shimozaki, M. Yoshioka, K. Masujin, M. Imamura, Y. Iwamaru, Y. Matsuura, K. Miyazawa, T. Yokoyama, S. Mohri); Hokkaido Research Organization, Shintoku, Japan (S. Fukuda)



Acknowledgment



This work was supported by a grant-in-aid from the BSE and Other Prion Disease Project of the Ministry of Agriculture, Forestry and Fisheries, Japan.



References



1.Murayama Y, Yoshioka M, Masujin K, Okada H, Iwamaru Y, Imamura M, Sulfated dextrans enhance in vitro amplification of bovine spongiform encephalopathy PrPSc and enable ultrasensitive detection of bovine PrPSc. PLoS ONE. 2010;5:e13152. DOIPubMed 2.Okada H, Iwamaru Y, Imamura M, Masujin K, Matsuura Y, Murayama Y, Detection of disease-associated prion protein in the posterior portion of the small intestine involving the continuous Peyer’s patch in cattle orally infected with bovine spongiform encephalopathy agent. Transbound Emerg Dis. 2011;58:333–43. DOIPubMed 3.Haley NJ, Seelig DM, Zabel MD, Telling GC, Hoover EA. Detection of CWD prions in urine and saliva of deer by transgenic mouse bioassay. PLoS ONE. 2009;4:e4848. DOIPubMed 4.Tamgüney G, Richt JA, Hamir AN, Greenlee JJ, Miller MW, Wolfe LL, Salivary prions in sheep and deer. Prion. 2012;6:52–61. DOIPubMed 5.Vascellari M, Nonno R, Mutinelli F, Bigolaro M, Di Bari MA, Melchiotti E, PrPSc in salivary glands of scrapie-affected sheep. J Virol. 2007;81:4872–6. DOIPubMed 6.Maddison BC, Rees HC, Baker CA, Taema M, Bellworthy SJ, Thorne L, Prions are secreted into the oral cavity in sheep with preclinical scrapie. J Infect Dis. 2010;201:1672–6. DOIPubMed 7.Gough KC, Baker CA, Rees HC, Terry LA, Spiropoulos J, Thorne L, The oral secretion of infectious scrapie prions occurs in preclinical sheep with a range of PRNP genotypes. J Virol. 2012;86:566–71. DOIPubMed 8.Mathiason CK, Powers JG, Dahmes SJ, Osborn DA, Miller KV, Warren RJ, Infectious prions in the saliva and blood of deer with chronic wasting disease. Science. 2006;314:133–6. DOIPubMed 9.Brown P, Andréoletti O, Bradley R, Budka H, Deslys JP, Groschup M, WHO tables on tissue infectivity distribution in transmissible spongiform encephalopathies. Geneva: World Health Organization; 2010 [cited 2011 Nov 2]. http://www.who.int/bloodproducts/tablestissueinfectivity.pdf



Figure Figure. . Western blot detection, using the serial protein misfolding cyclic amplification technique, of the abnormal (disease-associated) form of the prion protein (PrPSc) in concentrated saliva samples from 3 cows experimentally...



Suggested citation for this article: Okada H, Murayama Y, Shimozaki N, Yoshioka M, Masujin K, Imamura M, et al. Prion in saliva of bovine spongiform encephalopathy–infected cattle [letter]. Emerg Infect Dis [Internet]. 2012 Dec [date cited]. DOI: http://dx.doi.org/10.3201/eid1812.120528



DOI: 10.3201/eid1812.120528









DISSERTATION



CHRONIC WASTING DISEASE: A MODEL FOR PRION TRANSMISSION VIA SALIVA AND URINE


Submitted by Nicholas James Haley


Department of Microbiology, Immunology and Pathology In partial fulfillment of the requirements For the Degree of Doctor of Philosophy Colorado State University Fort Collins, Colorado Summer 2010



ABSTRACT OF DISSERTATION CHRONIC WASTING DISEASE: A MODEL FOR PRION TRANSMISSION VIA SALIVA AND URINE



Chronic wasting disease (CWD) of cervids is a prion disease distinguished by its high level of transmissibility, wherein bodily fluids and excretions are thought to play an important role. Typical of all prion diseases, CWD is characterized by the forced conversion of the normal prion protein (PrPC) into a misfolded isoform (PrPCWD), which has been shown to accumulate primarily in tissues of the lymphoid and nervous systems, though has also been found in other peripheral tissues including elements of the cardiovascular, musculoskeletal, and urogenital systems. Despite strong evidence that natural infection is acquired from the environment, as well as saliva and blood, a more thorough evaluation of excreta, including saliva, urine, and feces, is essential for a comprehensive foundation for (1) understanding how environmental CWDcontamination occurs, (2) developing in vitro assays for the antemortem identification of CWD-infected cervids, and (3) demonstrating the pathogenesis of the disease in the natural host.


In this dissertation, two approaches are used to identify infectious CWD prions and PrPCWD in the bodily fluids and tissues of CWD-exposed white-tailed deer: a novel bioassay system using a transgenic mouse line expressing the cervid PrP protein (Tg[CerPrP] mice), and a recently developed prion amplification assay known as serial iv protein misfolding cyclic amplification (sPMCA). In conjunction with immunohistochemistry and western blotting, these two assays were used to definitively identify CWD prions in saliva and urine, in addition to elements of the lymphoreticular system, central and peripheral nervous systems, and urogenital and oropharyngeal tissues. In initial experiments, concentrated urine and saliva samples from terminal CWD+ white-tailed deer, suspected of harboring infectious CWD prions, was assessed by Tg[CerPrP] bioassay and sPMCA. Authentic prion infectivity was detected in urine and saliva using both detection systems in the case of urine, though only mouse bioassay successfully demonstrated CWD prions in saliva. The concentration of abnormal prion protein in bodily fluids was very low, as indicated by: undetectable PrPCWD levels by traditional assays (western blot, ELISA) and prolonged incubation periods and incomplete TSE attack rates in inoculated Tg[CerPrP] mice. These findings helped to extend the understanding of CWD prion shedding and transmission and portend the detection of infectious prions in body fluids in other prion infections.


Based on the identification of CWD prions in saliva (“prionsialia”) and urine (“prionuria”), I next sought to determine whether deer previously exposed orally to urine and feces from CWD+ sources, while conventional test-negative, may actually be harboring very low level CWD infection not evident in the 19 month observation period in initial cervid bioassay studies. A selection of tissues, including those of the lymphoreticular and both central and peripheral nervous systems were fully examined, initially using Tg[CerPrP] bioassay to demonstrate true infectivity, and secondarily with sPMCA. Positive controls consisted of issues from CWD+ deer exposed orally to saliva; negative control tissue sets were collected from deer exposed orally and intracranially to


v


CWD-negative brain. PrPCWD was detected in the tissues of orally exposed deer by both sPMCA and Tg[CerPrP] mouse bioassay; each assay revealed very low levels of CWD prions previously undetectable by western blot, ELISA, or IHC. Serial PMCA analysis of individual tissues identified that obex alone was positive in urine/feces exposed deer. PrPCWD was amplified from both LRS and neural tissues of positive control deer but not from the same tissues of negative control deer. Detection of subclinical infection in deer orally exposed to urine and feces (1) suggests that a prolonged subclinical state can exist such that observation periods in excess of two years may be needed to detect CWD infection, and (2) illustrates the sensitive and specific application of sPMCA in the diagnosis of low-level prion infection.


Despite the confirmation of infectious prions in urine and saliva, along with conventional test-negative deer exposed to urine and feces, the manner in which infectivity is transferred to these excreta is unknown. To address this, I went on to apply sPMCA to tissues associated with production and excretion of urine and saliva in an effort to seek proximal sources of prion shedding. I blindly analyzed oropharyngeal and urogenital tissues, reproducibly demonstrating PrPCWD in each tissue examined in 3 rounds of sPMCA; whereas blood samples from the same animals and concurrent negative controls remained negative. Tissue distribution was affected by route of inoculation and CNS burden. The identification of PrPCWD in bodily fluids and conventional-test negative tissues – in the absence of detection by conventional methods – may indicate the presence of protease-sensitive infectious prions in excretory tissues not revealed by assays employing PK digestion or other means to remove PrPC reactivity.


vi


The continued evaluation of bodily fluids and peripheral tissues via sPMCA may therefore allow additional insights into prion transmission, trafficking, and pathogenesis.


Nicholas James Haley Department of Microbiology, Immunology and Pathology Colorado State University Fort Collins, CO 80523 Summer 2010


snip...


In summary, this study demonstrates for the first time amplifiable PrPCWD in various organs and tissues associated with prionsialia and prionuria. The ultimate source and mechanism of release into bodily fluids remain unknown, though elevated levels in both salivary gland and urinary bladder provides strong evidence that these tissues play a crucial role in prion excretion. In addition, the source and route of inoculation weighed heavily on the terminal peripheral distribution of PrPCWD, as did an individual’s apparent central nervous system burden. Finally, while this discovery provides evidence for prion invasion of peripheral excretory tissues, the timing of infiltration during CWD infection and the protease resistance profile of these prions warrant future studies in serial pathogenesis and detection of alternate infectious prion species.












Sunday, July 03, 2011


Prion Disease Detection, PMCA Kinetics, and IgG in Urine from Naturally/Experimentally Infected Scrapie Sheep and Preclinical/Clinical CWD Deer






Thursday, June 09, 2011


Detection of CWD prions in salivary, urinary, and intestinal tissues of deer: potential mechanisms of prion shedding and transmission





CHRONIC WASTING DISEASE: A MODEL FOR PRION TRANSMISSION VIA SALIVA AND URINE






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






Wednesday, March 18, 2009


Detection of CWD Prions in Urine and Saliva of Deer by Transgenic Mouse Bioassay






*** Tuesday, September 02, 2008


Detection of infectious prions in urine (Soto et al Available online 13 August 2008.)






Friday, October 26, 2012


CHRONIC WASTING DISEASE CWD PENNSYLVANIA GAME FARMS, URINE ATTRACTANT PRODUCTS, BAITING, AND MINERAL LICKS






TSS


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Tuesday, November 6, 2012

Transmission of New Bovine Prion to Mice, Atypical Scrapie, BSE, and Sporadic CJD, November-December 2012 update

This summary is not available. Please click here to view the post.
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