A Naturally Occurring Bovine Tauopathy Is Geographically Widespread in the UK

Research Article

 

A Naturally Occurring Bovine Tauopathy Is Geographically Widespread in the UK

 

Martin Jeffrey, Affiliation: Animal and Plant Health Agency, Lasswade Veterinary Laboratory, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, Scotland

 

⨯ Pedro Piccardo, Affiliation: Laboratory of Bacterial and TSE-agents, Food and Drug Administration, Rockville, Maryland, United States of America

 

⨯ Diane L. Ritchie, Affiliation: National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, School of Clinical Sciences, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, United Kingdom

 

⨯ James W. Ironside, Affiliation: National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, School of Clinical Sciences, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, United Kingdom

 

⨯ Alison J. E. Green, Affiliation: National CJD Research & Surveillance Unit, Centre for Clinical Brain Sciences, School of Clinical Sciences, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, United Kingdom

 

⨯ Gillian McGovern * E-mail: gillian.mcgovern@apha.gsi.gov.uk

 

Affiliation: Animal and Plant Health Agency, Lasswade Veterinary Laboratory, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, Scotland

 

⨯ A Naturally Occurring Bovine Tauopathy Is Geographically Widespread in the UK Martin Jeffrey, Pedro Piccardo, Diane L. Ritchie, James W. Ironside, Alison J. E. Green, Gillian McGovern PLOS x Published: June 19, 2015 DOI: 10.1371/journal.pone.0129499

 

Abstract

 

Many human neurodegenerative diseases are associated with hyperphosphorylation and widespread intra-neuronal and glial associated aggregation of the microtubule associated protein tau. In contrast, animal tauopathies are not reported with only senescent animals showing inconspicuous tau labelling of fine processes albeit significant tau aggregation may occur in some experimental animal disease. Since 1986, an idiopathic neurological condition of adult cattle has been recognised in the UK as a sub-set of cattle slaughtered as suspect bovine spongiform encephalopathy cases. This disorder is characterised by brainstem neuronal chromatolysis and degeneration with variable hippocampal sclerosis and spongiform change. Selected cases of idiopathic brainstem neuronal chromatolysis (IBNC) were identified from archive material and characterised using antibodies specific to several tau hyperphosphorylation sites or different isoforms of the tau microtubule binding region. Labelling was also carried out for alpha synuclein, ubiquitin, TDP43, Aβ1–42, Aβ1–40. Widespread tau labelling was identified in all IBNC brains examined and with each of seven tau antibodies recognising different hyperphosphorylated sites. Labelling with each antibody was associated with dendrites, neuronal perikarya and glia. Thus IBNC is a sporadic, progressive neurological disease predominantly affecting aged cattle that occurs throughout the UK and is associated with hyperphosphorylation of tau, a rare example of a naturally-occurring tauopathy in a non-primate species. Secondary accumulation of alpha synuclein and ubiquitin was also present. The neuropathology does not precisely correspond with any human tauopathy. The cause of IBNC remains undetermined but environmental factors and exposure to agrochemicals needs to be considered in future aetiological investigations.

 

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Discussion Tau is phosphorylated at about 30–40 sites in normal human brains and is also minimally phosphorylated in normal adult mammalian brains. In some human disease states tau may become hyperphosphorylated with up to 60 phosphorylation sites. In animals, P- tau has been described as thread like processes in the brains of clinically normal aged animals [18] and is inconsistently associated with some experimental and naturally occurring prion diseases [19,20] as it is also in man [21]. Some presumed constitutionally expressed isoforms of tau are abundant within the neuronal cytoplasm of some animal species [16,22]. Numerous tauopathies exist in man [23]. Some tauopathies such as Primary Age Related Tauopathy (formerly known as neurofibrillary dementia) [23,24] may lack clinical features in some individuals but many tauopathies have distinctive clinico-pathological presentations [23]. In contrast, neither clinical disease nor age related syndromes have previously been associated with consistent tau hyperphosphorylation in animals. In IBNC P-tau is both invariably present and associated with neurodegenerative features [2] in cows presenting with distinct neurological signs [3]. Thus IBNC appears to be the first naturally occurring and geographically widespread tauopathy in a species other than humans.

 

P-tau may aggregate into intra-cellular fibrillar structures. In Alzheimer’s disease aggregated tau takes the form of paired helical filaments. These may be identified by silver impregnation methods and are usually referred to as neurofibrillary tangles. Fibrils composed of aggregated tau molecules are not confined to Alzheimer’s disease but may occur as straight or random filaments in some other human tauopathies (Table 2). IBNC appear to lack intracellular neurofibrillary tangles, as shown by negative silver stains and by electron microscopic examinations suggesting that aggregation of P-tau in IBNC may not progress to formation of filaments.

 

Many human neurodegenerative diseases show abnormalities of tau and microtubules and although most are considered complex proteinopathies, some familial diseases with mutations of the microtubule associated protein gene, such as familial fronto-temporal dementia are considered pure tauopathies [23,25]. No genetic information about the bovine tau gene was available for cases of IBNC, but the involvement of multiple cattle breeds and the sporadic but geographically widespread distribution of IBNC cases across Scotland [2] and elsewhere within the UK argues against a familial cause of disease.

 

IBNC shows hyperphosphorylation at numerous sites across the tau molecule, albeit of those sites tested some were more conspicuous than others. 3R forms of tau were recognised but not the 4R forms. Labelling of 3R tau is known to require specific pre-treatments [16] and labelling for 4R may be capricious. The absence of 4R labelling persisted when methods considered highly favourable for detection of 3 and 4R isoforms in man was used [16], but in the absence of any 4R positive bovine control tissues we should be cautious of concluding that no 4R forms were present. Some species, such as the mouse, do not generate both 3R and 4R isoforms of tau [26]. However, adult cows generate isoforms with the N-terminal extensions 3R1N, 3R2N, 4R1N, 4R2N [26], which may suggest that IBNC represents a predominantly 3R tauopathy in cattle.

 

Tauopathies in man are classified according to the physical state of aggregation of abnormal tau, by the molecular size and nature of P-tau, by the neuroanatomical distribution of lesions and by additional neurodegenerative features [8,23,27,28]. The Western blot data from the three IBNC brains tested suggests that tau with multiple molecular weights is present, albeit the Western blots do not test the state of phosphorylation of the tau recognised. The immunoblot data therefore confirms the presence of multiple tau molecular states in IBNC brains, but the similar presence of tau in control adult cattle brains makes further interpretation difficult. Significant additional work to test specifically for the presence of hyperphosphorylated tau forms will be necessary to provide meaningful interpretation. Nevertheless both the immunoblotting and immunohistochemical data are consistent with IBNC brains containing multiple molecular weight isoforms of P-tau, potentially with a range similar to that found in Alzheimer’s disease. However, plaques or diffuse accumulations of Aβ1–40 or Aβ1–42 were absent from IBNC brains. Hippocampal sclerosis in man may be associated with TDP-43 immunolabelling, but this too was absent in IBNC. The predominant glial tau association of IBNC has similarities to the tau gliopathy reported for argyrophilic grain disease, progressive supranuclear palsy and corticobasal degeneration [22] but, in contrast to the predominant 3R tauopathy found in IBNC, these human neurodegenerations are all 4R tauopathies (Table 2). In common with other protein misfolding diseases, IBNC appears to be a complex proteinopathy with evidence for additional secondary accumulation of alpha synuclein, ubiquitin, and possibly PrP [5]. However there is no evidence of Lewy bodies, neurites or other primary alpha synuclein pathology such as is found in Parkinson’s disease. Thus the nature of the tauopathy in IBNC does not precisely parallel that of any of the existing human tauopathies ([22] and Table 2); however, it appears to represent a naturally-occurring predominantly 3R tauopathy in a non-primate species.

 

IBNC is a chronic progressive neurological illness that is widespread and occurs sporadically throughout the UK in aged cattle. Clinical signs of IBNC include behavioural changes, increased apprehension and locomotor problems such as tremor and stiffness of gait, and weight loss [2,3]. Difficulty in swallowing with increased salivation is also reported is some cases. Attempts to find the cause of IBNC have so far been unsuccessful. Small scale and largely unpublished studies of IBNC have not identified infectious, metabolic or micronutrient deficiencies that are known to cause neurodegeneration in cattle [6]. It is now widely understood that both genetic and environmental factors contribute to the pathogenesis of some human dementias and several environmental risk factors have been identified for some human Parkinsonian syndromes. In particular exposure to insecticides and herbicides and employment in the agricultural or horticultural industries increases risk [29,30,31]. Although the mechanisms remain uncertain, it has been suggested that diverse toxins may interact with alpha synuclein to initiate aggregation of alpha synuclein in Parkinson’s disease [32]. Experimental exposure of rodents to the insecticides rotenone, [33] the herbicide paraquat or the fungicide maneb (a dithiocarbamate) each results in striato-nigral dopaminergic neuron loss [32]. In the absence of any specific aetiological cause of IBNC yet identified, and based on the existing epidemiology and presence of P-tau we have considered the possibility that IBNC might also have a significant environmental component. Epidemiological investigations to explore usage of herbicides, insecticides, parasiticides and other chemicals used in agriculture would be helpful in future investigations of IBNC and might provide further insight into some causes of neurodegeneration in man.

 

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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0129499

 

 

Greetings,

 

I was stunned by this report.

This Research Report should have been titled ;

‘’It Appears A Naturally Occurring Bovine Tauopathy Is Geographically Widespread in the UK’’

 

I would kindly like to comment please, as follows ;

 

 

>>>Thus IBNC _appears_ to be the first naturally occurring and geographically widespread tauopathy in a species other than humans.<<<

 

>>>IBNC _appear_ to lack intracellular neurofibrillary tangles,<<<

 

>>>Thus IBNC _appears_ to be the first naturally occurring and geographically widespread tauopathy in a species other than humans<<<

 

>>>IBNC appears to be a complex proteinopathy with evidence for additional secondary accumulation of alpha synuclein, ubiquitin, and possibly PrP [5]. <<<

 

>>>however, it appears to represent a naturally-occurring predominantly 3R tauopathy in a non-primate species.<<<

 

>>>In the absence of any specific aetiological cause of IBNC yet identified, and based on the existing epidemiology and presence of P-tau we have considered the possibility that IBNC might also have a significant environmental component. Epidemiological investigations to explore usage of herbicides, insecticides, parasiticides and other chemicals used in agriculture would be helpful in future investigations of IBNC and might provide further insight into some causes of neurodegeneration in man.<<<

 

 

This is supposition at best in my opinion, and at worse, I will refrain from comment.

 

Too many _appears_ , appears this, appears that.

 

Too many _In the absence of any specific aetiological cause of IBNC yet identified_

 

is this what science has come to?

 

has science become some entwined with corporate special interest, do we change science now?

 

I believe that is far too early to rule out IBNC as a Transmissible Spongiform Encephalopathy TSE prion disease, either of typical or typical strain.

 

it can be argued that there is potential for Alzheimer’s to be a low dose TSE Prion disease ;

 

http://www.plosone.org/annotation/listThread.action?root=82860

 

what about horizontal and or vertical transmission of an atypical strain of the BSE TSE prion disease into a low dose that is not detectible with TSE Prion testing to date?

 

what about a completely different strain, another atypical, of the TSE prion disease, to low to detect to date, and I stress to date?

 

to abandon the TSE prion and IBNC link there from would be foolish in my opinion.

 

SEAC, FatPride, BSE Inquiry, have never found a link to pesticides, or OP’s, or metals, as a _cause_, to any TSE prion disease.

 

I have also followed the metals, pesticide debate as a cause for the TSE prion disease. to date, this has proven to be fruitless for any _cause_ of the TSE prion disease. not to say the potential for these factors for one to be more susceptible to a TSE prion from surrounding environmental factors i.e. surrounding TSE prion exposures from the various routes and sources of the TSE prion disease (see metals and pesticide i.e. FatePride towards the bottom). from Mark Purdey and his research, to a farmer with BSE that treated his kids with OP’s for head lice, and nothing scientific to date has confirmed a link to the TSE prion disease as a _cause_.

 

We MUST not abandon transmission studies, and or any link to the TSE prion disease.

 

IT appears, in the absence of any scientific link to any specific herbicides, insecticides, parasiticides and other chemicals to date to IBNC, to just explore other options instead of the transmission studies to prove one way or the other whether or not the IBNC or BBD or whatever you want to call this, while ignoring the existing epidemiology and knowledge of the TSE prion disease with the primitive TSE prion testing to date, it appears all this would be foolish, it appears this would be very questionable, in my opinion. ...

 

Terry S. Singeltary Sr.

 

please see ;

 

Prion-like transmission and spreading of tau pathology Invited Review

 

Prion-like transmission and spreading of tau pathology Florence Clavaguera1, Jürgen Hench1, Michel Goedert2 and Markus Tolnay1,* DOI: 10.1111/nan.12197

 

This article is protected by copyright. All rights reserved.

 

Additional Information(Hide All) Author InformationPublication History Author Information 1 Institute of Pathology, University Hospital Basel, Schönbeinstrasse 40, CH-4031 Basel, Switzerland 2 MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK * Please send correspondence to Markus Tolnay at the above address. Email: markus.tolnay@usb.ch

 

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/nan.12197

 

Publication History Accepted manuscript online: 17 NOV 2014 01:23AM EST Manuscript Accepted: 13 NOV 2014

 

Abstract

 

Filaments made of hyperphosphorylated tau protein are encountered in a number of neurodegenerative diseases referred to as “tauopathies”. In the most prevalent tauopathy, Alzheimer's disease, tau pathology progresses in a stereotypical manner with the first lesions appearing in the locus coeruleus and the entorhinal cortex from where they appear to spread to the hippocampus and neocortex. Propagation of tau pathology is also characteristic of argyrophilic grain disease, where the tau lesions appear to spread throughout distinct regions of the limbic system. These findings strongly implicate neuron-to-neuron propagation of tau aggregates. Isoform composition and morphology of tau filaments can differ between tauopathies suggesting the existence of conformationally diverse tau strains. ***Altogether, this points to prion-like mechanisms in the pathogenesis of tauopathies.

 

 http://onlinelibrary.wiley.com/doi/10.1111/nan.12197/abstract?campaign=wolacceptedarticle

 

 

‘’experiments using bovinised, ovinised and humanised mice indicate that IBNC is transmissible, the ability of surveillance to detect IBNC should be examined. It would be important to conduct transmission experiments using brains from IBNC cases proven, as far as possible, not to have BSE.’’

 

 

SEAC 103/1

 

SPONGIFORM ENCEPHALOPATHY ADVISORY COMMITTEE

 

Draft minutes of the 102nd meeting held on 4th March 2009 Nobel House, 17 Smith Square, London SW1P 3JR

 

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ITEM 5 – NEW RESULTS ON IDIOPATHIC BRAINSTEM NEURONAL CHROMATOLYSIS (IBNC) FROM THE VETERINARY LABORATORIES AGENCY (VLA)

 

14. Dr Martin Jeffrey (Veterinary Laboratories Agency (VLA)) presented an overview of a recent publication on Idiopathic Brainstem Neuronal Chromatolysis (IBNC)4. During the period 1987 to 1992, VLA examined the neuropathology of whole brains from all submissions made under the BSE orders in Scotland to look for possible strain variation or mutation of the existing BSE strain or other prion diseases of cattle. During the course of these investigations a small number of cases of IBNC were identified. Abnormally accumulated prion protein was found in the brains of the IBNC cases. Dr Jeffrey suggested that these findings indicate that the range of prion disease pathology may be wider than thought or that abnormalities of prion protein gene expression might be associated with brain lesions unconnected with classical prion diseases.

 

15. A member noted that IBNC appears to be a rare disease and the prevalence of IBNC seems not to have increased over time. Dr Jeffrey noted that the detection rate of IBNC is dependent on the design of cattle surveillance and it is possible that cases of IBNC may be missed by current surveillance. Nevertheless, it is likely that IBNC is rare. A member suggested that should transmission 3 Truscott, J.E. and Ferguson, N. M. (2008) Control of scrapie in the UK sheep population. Epidemiology and Infection, 8 August 2008, on-line, doi: 10.1017/S0950268808001064. 4Jeffrey et al. (2008) Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle? 4, 38.

 

experiments using bovinised, ovinised and humanised mice indicate that IBNC is transmissible, the ability of surveillance to detect IBNC should be examined. It would be important to conduct transmission experiments using brains from IBNC cases proven, as far as possible, not to have BSE.

 

16. A member asked about whether differential diagnosis was made on BSE suspect cases that subsequently were found not to be BSE. Dr Yvonne Boyd (Defra) noted that currently less than 10% of suspected BSE suspect cases were subsequently confirmed. Defra was funding a research project to examine a number of clinical BSE suspects subsequently found not to be BSE, but routine differential diagnosis was not carried out on all such cases. Dr Jim Hope (VLA) added that such cases were not specifically investigated for the presence of other neurological diseases; only the presence of spongiform change and the properties of the prion protein were assessed. However, obvious differential diagnoses were reported, e.g. meningioencephalitis, if detected.

 

17. A member noted that even though prion protein accumulation was evident in IBNC cases, the form of prion protein produced was protease sensitive, indicating that IBNC may not be a form of TSE. Dr Jeffrey explained that, from the biochemical studies conducted, an abnormally folded, but protease sensitive, form of prion protein could not be ruled out.

 

18. A member asked if any of the cases of IBNC examined showed evidence of possible co-infection with classical BSE. Dr Jeffrey replied that as the neuropathological lesions of IBNC and BSE differed, co-infection should be detectable. However, no evidence of co-infection had been detected. A member suggested it may be possible to re-examine archived BSE brains for the possibility of IBNC co-infection to establish whether IBNC is indeed a rare disease. Dr Jeffrey noted that as IBNC predominantly affects older cattle, the age of the cattle brains would be a factor in such an investigation.

 

19. A member asked if the sequence of the prion protein gene had been studied in the IBNC cases as this can influence the pathogenesis and neuropathology of prion diseases. Dr Jeffrey replied that no detailed studies had been conducted.

 

20. A member noted that IBNC appeared to be a neurological condition and therefore the specified risk material controls would confer public health protection should IBNC be zoonotic.

 

21. The Chair summarised the discussion, noting that IBNC appears to pose no immediate high risk to human health. It appears to be a rare disease, although current surveillance may miss cases. It cannot be concluded if IBNC is transmissible, or not. Transmission studies using material from IBNC cases proven not to be BSE, that include transgenic mice lines, are important. Studies to investigate whether IBNC is associated with a normal or abnormal form of prion protein could be informative.

 

ITEM 6 – UPDATE ON CJD EPIDEMIOLOGY

 

22. Professor Richard Knight (National CJD Surveillance Unit) updated SEAC on the latest figures for the number of clinical vCJD and sporadic CJD (sCJD) cases. To date there had been 168 definite and probable clinical cases of vCJD in the UK - 165 from dietary infection with BSE and three from vCJD infection via blood transfusion. Four cases are still alive. The number of deaths from vCJD peaked at 28 in 2000 and had since declined with one known death in 2008. The trend in incidence of vCJD deaths fits the quadratic-exponential model. The median age of death is 28 years of age. No individuals born after 1989 have developed vCJD to date. Analysis of vCJD deaths by birth cohort supports the hypothesis that susceptibility to vCJD from dietary exposure to BSE may be age-related with a peak in susceptibility between five and 20 years of age.

 

23. Professor Knight explained that all the clinical vCJD cases genotyped to date were of the MM genotype with the exception of one case of the MV genotype recently classified as possible vCJD. This patient had died. Although the clinical features in life suggested this was a case of vCJD, it had not been possible to undertake a tonsil biopsy in life or neuropathological examination post mortem so the diagnosis could not be confirmed. The patient was born in 1978, with disease onset in 2007 and death in 2009. The clinical profile of this MV case was consistent with that observed for MM cases suggesting that the neuropathological profile of vCJD in MV and MM cases may be similar.

 

24. Professor Knight noted that four vCJD patients had been treated with intra-ventricular pentosan polysulphate (PPS) in the UK, in addition to one sCJD, two Gerstmann-Sträussler-Scheinker (GSS) disease and one human growth hormone (hGH) case. There is no evidence of benefit from the use of PPS for the sCJD, GSS and hGH cases. However, it appears PPS may have significantly prolonged the clinical phase of the illness in the vCJD cases treated, although no significant improvement in the clinical condition of these patients had been observed.

 

25. Professor Knight explained that elsewhere in the world 44 clinical vCJD cases had been reported with 23 in France, five in Spain, four in the Republic of Ireland, three in each of the USA and the Netherlands, two in Portugal and single cases in Canada, Saudi Arabia, Italy and Japan. Infection was presumed to have occurred in the UK in respect of two Irish and two USA cases, one French case, one Japanese case and one Canadian case. The time of the peak of onset of vCJD was five years later in non-UK countries than in the UK.

 

26. Professor Knight summarised studies to examine potential bloodborne exposures to vCJD. The Transfusion Medicine Epidemiology Review (TMER) identified 66 patients as recipients of labile blood components from donors whom later developed vCJD. Forty three of those patients had died due to non-vCJD related illnesses but three recipients developed clinical vCJD and one subclinical vCJD infections. The reverse TMER study identified three vCJD cases as receiving blood from vCJD infected donors. A study of plasma donations prepared from 1986 to 1998 plasma had identified 25 units of plasma prepared from donations from 11 individuals who later developed vCJD.

 

27. Professor Knight summarised data on sCJD cases. From May 1990 to January 2009, 1027 cases of sCJD had been identified in the UK with a mean age at death of 67 years and genotype distribution of 63% MM, 19% MV and 18% VV at codon 129 of the prion protein gene.

 

28. Members asked in what circumstances an autopsy is legally required. Professor Knight explained that autopsy may be legally required when the cause of death is considered not to be from natural causes or is unknown. However, the wishes of the family of the deceased are also considered.

 

29. Dr Elaine Gadd (Department of Health (DH)) asked about the clinical state of the vCJD cases treated with PPS. Professor Knight explained that the neurological impairment of the patients when treatment began was so advanced that any subtle changes in clinical state would be difficult to assess objectively. The condition of two patients is considered to have significantly deteriorated, whilst one patient may have improved slightly.

 

ITEM 7 – COMPARING THE RELATIVE RISK OF vCJD TRANSMISSION VIA SINGLE UNIT AND POOLED PLASMA FROM UK AND NON-UK SOURCES (SEAC 102/3)

 

30. Mr Stephen Dobra (DH) presented an overview of the risk assessment that had been developed by the Department of Health. He explained that there are three Fresh Frozen Plasma (FFP) products in use in the UK: (i) single unit FFP from UK donors given to recipients over 16 years of age, (ii) single unit methylene-blue treated FFP sourced from donors in the United States of America and given to patients under 16 years of age, and (iii) solvent detergent treated FFP (SD FFP) manufactured from pooled plasma currently sourced from countries with no known vCJD cases (although some, such as Germany, have a known BSE risk) given to patients with Thrombotic Thrombocytopenic Purpura (TTP). As most FFP is sourced from UK donors, there is a potential risk of vCJD transmission from its use. Prion reduction technologies may be available in the future for pooled SD FFP.

 

31. Mr Dobra explained that the risk assessment had been prepared to support decision making by the Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) which is considering options for extending the use of imported plasma to all recipients and National Health Service Blood and Transplant which is considering the procurement of plasma from alternative source countries. The risk assessment examines the relative residual risk from use of plasma taking into account the source country, whether it is single unit or pooled, and the method of processing. SEAC was being asked to review the methodology used for the sourcing and pooling elements of the risk assessment. DH will convene an expert group to assess the impact of processing taking into account previous SEAC advice.

 

32. Members suggested that the presentation of the risk assessment could be improved to provide greater clarity on the reasoning behind some of the assumptions made.

 

33. A member asked about the estimation of the probability that infectivity would be carried by a plasma product from pooled plasma donations that had been contaminated by a donor infected with vCJD. Mr Dobra suggested that in low infectivity scenarios, infectivity might not be present in all of the plasma product units produced from a contaminated pool as there may be an uneven distribution of infectivity throughout the pool. Members noted that the physico-chemical nature of infectivity in plasma is not known. It may be homogeneously spread within the pool or remain in the form of discrete entities spread unevenly, or something between these two extremes. There may be no low dose threshold for infection.

 

34. Members asked what confidence there may be in the results from the risk assessment given the large number of variables with large uncertainties. It was noted that as the relative risks (as opposed to absolute risks) posed by plasma products were being estimated, assumptions around the timing, level and distribution of infectivity in blood where there is much uncertainty would not appreciably affect the estimations made. The best way to manage other assumptions where there is large uncertainty, such as around the prevalence of vCJD in the UK and other countries, would be to develop a range of scenarios incorporating reasonable high and low value estimates for such parameters. It was noted that some patients received a large number of transfusions of plasma and plasma products. It may be possible to rule out some scenarios on the basis of observations made on these groups of patients. Members reiterated the importance SEAC placed on obtaining better estimates for the prevalence of subclinical vCJD through a post mortem tissue archive.

 

35. A member suggested that experiments to examine the infectivity of unused batches of plasma products might provide useful data. It was considered that such experiments may be difficult to conduct as there may be a small number of contaminated batches and they would be difficult to identify.

 

36. A member asked why prion reduction technologies would only be applied to pooled plasma. Mr Dobra explained that the only proposal of which he was aware had been developed by a manufacturer of pooled plasma and involved filtering a large volume of plasma through a column. The Chair remarked on the lack of independent validation of the efficacy of prion reduction filters to date.

 

37. A member asked whether the risk assessment could take into account the measures taken in different countries to prevent dietary exposure to BSE and the movement of people from other countries to the UK during the BSE epidemic. Mr Dobra explained that there are no consistent data available to assess differences in dietary exposure to BSE in different European countries. Most countries excluded from donating blood anyone who had visited or been resident in the UK for a significant period of time.

 

38. A member noted that the risk of vCJD transmission alters depending on the age of the blood donor and asked whether restrictions on the age of donation could be introduced to manage the vCJD transmission risks. Mr Dobra explained that this was possible but would require clear advice from SEAC on the difference in risk and was complicated by the need to ensure sufficient supplies of blood.

 

39. The Chair summarised the discussion, noting that the committee felt that the best way of handling the uncertainties around key assumptions made in the risk assessment is to use reasonable high and low values for each parameter to derive a range of scenarios. Scenarios could be validated against the number of infections observed in populations that had received large numbers of transfusions of plasma products.

 

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http://www.seac.gov.uk/papers/103-1.pdf

 

Saturday, October 19, 2013

 

A comparative study of modified confirmatory techniques and additional immuno-based methods for non-conclusive autolytic Bovine spongiform encephalopathy cases

 

BMC Veterinary Research 2013, 9:212 doi:10.1186/1746-6148-9-212 Rocío Sarasa (rociosar@unizar.es) Dietmar Becher (becher@micromun.de) Juan J Badiola (badiola@unizar.es) Marta Monzón (mmonzon@unizar.es)

 

ISSN 1746-6148

 

Article type Research article

 

Submission date 6 March 2013

 

Acceptance date 9 October 2013

 

Publication date 18 October 2013

 

Article URL http://www.biomedcentral.com/1746-6148/9/212

 

BMC Veterinary Research

 

© 2013 Sarasa et al.

 

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

A comparative study of modified confirmatory techniques and additional immuno-based methods for non-conclusive autolytic Bovine spongiform encephalopathy cases

 

Rocío Sarasa1 Email: rociosar@unizar.es Dietmar Becher2 Email: becher@micromun.de Juan J Badiola1 Email: badiola@unizar.es Marta Monzón1* * Corresponding author Email: mmonzon@unizar.es 1 Research Centre for Encephalopathies and Transmissible Emerging Diseases, University of Zaragoza, Zaragoza, Spain 2 Micromun Privates Institut für Mikrobiologische Forschung GmbH, Greifswald,

 

Germany

 

Abstract

 

Background

 

In the framework of the Bovine Spongiform Encephalopathy (BSE) surveillance programme, samples with non-conclusive results using the OIE confirmatory techniques have been repeatedly found. It is therefore necessary to question the adequacy of the previously established consequences of this non-conclusive result: the danger of failing to detect potentially infected cattle or erroneous information that may affect the decision of culling or not of an entire bovine cohort. Moreover, there is a very real risk that the underreporting of cases may possibly lead to distortion of the BSE epidemiological information for a given country.

 

In this study, samples from bovine nervous tissue presenting non-conclusive results by conventional OIE techniques (Western blot and immunohistochemistry) were analyzed. Their common characteristic was a very advanced degree of autolysis. All techniques recommended by the OIE for BSE diagnosis were applied on all these samples in order to provide a comparative study.

 

Specifically, immunohistochemistry, Western blotting, SAF detection by electron microscopy and mouse bioassay were compared. Besides, other non confirmatory techniques, confocal scanning microscopy and colloidal gold labelling of fibrils, were applied on these samples for confirming and improving the results.

 

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Discussion

 

All the studied bovine samples were confirmed as BSE positive cases thanks to the results provided by immunocytochemistry, electron microscopy and bioassay. Despite all the applied techniques being standardized for increasing their capability to detect PrPsc, the extremely scarce concentration of PrPsc in the samples is proposed here as the most coherent reason why non-conclusive results (weak signal presenting an unconventional pattern) were provided by Western blotting as well as showing different titers in the bioassay (reflected by the lack of 100% success of transmission in all the mice included in it). Therefore, the positive results provided by immunohistochemistry on murine bioassay ultimately demonstrated that initial samples were infectious and transmitted the disease. This was also concluded by immunocytochemistry and SAF detection by electron microscopy being applied on the initial samples. However, rapid tests and immunoblotting did not result useful for convincingly confirming these results.

 

Although rapid techniques applied in this study achieved their objective as screening tests by showing a non-conclusive signal in the samples analyzed, they were not able to give definite results, demonstrating a lower sensitivity compared to some of the confirmatory techniques (not all in this occasion, since immunoblotting, despite the combined protocol described, was not able to improve the results provided by rapid tests in terms of sensitivity). Nonconclusive diagnosis obtained by these techniques in the bovine as well as false negative diagnosis in the murine samples have been previously justified on the basis of the low PrPsc concentration and the unsuitable selection of area to be analyzed [29]. Both are unavoidable and intrinsic features for the samples studied here. Overall, these findings might call into question the recent proposal determined by the OIE which dictates that two equal results with two different rapid techniques are enough to give an official BSE confirmation [30]. Furthermore, the results of this study confirm immunocytochemistry as a useful and rapid tool for diagnosis in liquid state samples, solving a relevant problem in BSE and Scrapie epidemiology. As it had been previously impossible to apply histopathological examination due to the advanced degree of autolyisis of the analyzed samples, immunohistochemistry was evidenced as the first and reliable technique to diagnosis of samples included here.

 

Immunocytochemistry has been demonstrated here as a technique capable to provide final results for bovine samples. Moreover, this study first demonstrates the reliability of this technique established by Monleón et al. [18] since their results have been corroborated by other confirmatory techniques, specifically, by electron microscopy and by in vivo tools (bioassay). Confirmation of the immunocytochemical positive results by electron microscopy clearly discards the possible subjectivity and non-specificity which some authors could state for the immunocytochemical assessment established, since SAF visualization has been demonstrated to be exclusive to TSEs [31]. In spite of the proportion and length of fibrils being lower than those previously described in conventional positive cases [32], the immunolabelling of these fibrils by colloidal gold [33] unequivocally identified PrPsc in all of them. This slight difference in appearance is probably associated with the low PrPsc concentration assumed at the beginning and finally evidenced in this study. Besides, the visualization of paired gold deposits which seem to correspond with PrPsc dimers described by Dourmashkin et al. [34], supports this hypothesis, associating gold deposits to areas of potential formation of fibrils [35]. As a consequence, although it is a technique currently fallen into disuse, SAF visualization by electron microscopy is confirmed in this study as a technique with high sensitivity despite PrPsc concentration and autolysis of the sample, demonstrating to be useful for diagnosing this kind of samples.

 

On the other hand, although the bioassay presented a transmission rate lower than expected (only 24% of the inoculated mice developing clinical signs), its sensitivity was 100% since it confirmed the positive diagnosis of the bovine samples. The low number of affected mice, expressed in the low percentage of animals which presented clinical signs or positive result by diagnostic techniques, could be explained by several reasons. Despite partly avoiding the problem of species barrier by use of bovinized transgenic mice [36], the autolytic state of samples could have hampered the choice of the area of study where PrPsc was present.

 

Nevertheless, the main responsible factor for this failure seems to be the low initial PrPsc concentration due to, advancement of the protease digestion associated with the putrefaction process, the serial dilutions and heat treatment which had to be applied on the samples before inoculation. This scarce PrPsc presence could elongate the incubation period and, indirectly, cause false negatives in those mice which died prematurely, by natural death or euthanasia, before presenting clinical signs [37] or not presenting enough concentration of PrPsc to be detected by the applied techniques at that moment [38]. The fact that the only mouse clearly considered positive by rapid tests and the only mouse showing PrPsc plaques (as usually seen in BSE inoculated mice) [39] belonged to the group of animals where the highest concentration was used for inoculation, confirms this theory. Moreover, the presence of isolated fibrils in the mice analyzed [40] instead of grouped fibrils visualized by electron microscopy in the only positive mouse by rapid tests [41], would, once again, correlate with this hypothesis.

 

As for the variance between the presence of PrPsc deposits and presentation of clinical signs found in some mice, PrPsc concentration used for inoculation could affect the results but also other explanations arise on this matter [42]. The possibility of a transmission of the disease without neurological signs [43] or a possible non-exclusive relationship between PrPsc and infectivity [44-46] and neurodegeneration [47], among them. Besides, the demonstration of the existence of animals as persistent carriers [48] or with a subclinical state of the disease [47], already described in mice with high titers of infection but no symptoms [49], should be borne in mind. This same lack of correlation between PrPsc and infectivity could be reflecting in the animals with symptoms but no PrPsc deposits [50], considering in this case that the disease might be transmitted without detectable PrPsc [44], even with high titers [51]. Further studies with non-diagnostic aims but for identification of astrocytes co-locating with PrPsc were developed here, as mentioned in Material and Methods section. The relationship between PrPsc and glial cells observed by conventional immunohistochemistry, was confirmed by confocal microscopy showing an evident co-localization. This finding would put in evidence the possibility of the participation of these cells, possibly across the haematoencephalic barrier [27,52], in the prion propagation in the model used here [53]. On this occasion, it was not possible to associate the studied samples to classical or atypical BSE owing to the lack of success to provide a clear banding pattern by Western blotting and/or a characteristic profile by immunohistochemistry, the lack of reference to previous data on incubation periods and the inability to determine lesion profiles in the mouse line. All these facts, as it has been stated, probably due to the very scarce concentration of PrPsc. Otherwise, whether the agent present in samples was atypical BSE or classical BSE with really low PrPsc deposits and low infectivity titers was not possible to be determined.

 

Conclusions

 

In conclusion, demonstration of transmission of the disease even with low concentrations of PrPsc [54], highlights BSE’s ability to adopt different behavior, even sometimes similar to Scrapie [55], should reinforce that vigilance is required in interpreting results so that subtle changes do not go unnoticed. Additionally, to maintain a continued supervision of the techniques which are applied in the routine diagnosis would prove essential for the ultimate eradication of the disease. A study of the actual BSE presence should be considered as necessary because a state of sporadic prevalence could exist [56] and samples without a diagnosis [57,58] could reach the food chain, involving therefore a risk for public health.

 

Keywords

 

TSEs, BSE, Confirmatory diagnosis, Non-conclusive cases

 

http://www.biomedcentral.com/content/pdf/1746-6148-9-212.pdf

 

From: Terry S. Singeltary Sr.

 

Sent: Tuesday, August 13, 2013 3:58 PM

 

To: Science.Advisory.Council@defra.gsi.gov.uk

 

Subject: Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle?

 

Greetings Honorable Science Advisory Council et al @ DEFRA,

 

I wish to ask a question about something I have seen no updates on, that concerns me.

 

IDIOPATHIC BRAINSTEM NEURONAL CHROMATOLYSIS IBNC or what I some times call, IBNC BSE.

 

I have seen nothing in the scientific literature updated on this in years, since around 2008, then it was like it fell off the face of the earth ?

 

can you please give me some sort of update on the IBNC BSE science to date ?

 

how many cases of IBNC BSE have been detected ?

 

is there an ongoing surveillance for this the IBNC BSE, and are the BSE test even capable of detecting it ?

 

could the USA and or North America even detect, if they were even looking for it ?

 

latest studies, if any more since "All of the 15 cattle tested showed that the brains had abnormally accumulated PrP" ?

 

thank you,

 

kind regards, terry

 

references as follows ;

 

Research article Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle? Martin Jeffrey1*, Belinda Baquero Perez2, Stuart Martin1, Linda Terry2 and Lorenzo González1

 

* Corresponding author: Martin Jeffrey m.jeffrey@vla.defra.gsi.gov.uk

 

Author Affiliations

 

1 Veterinary Laboratories Agency (VLA-Lasswade), Pentlands Science Park, Bush Loan, Midlothian EH26 0PZ, UK

 

2 VLA-Weybridge, Addlestone, Surrey, KT15 3NB, UK

 

For all author emails, please log on.

 

BMC Veterinary Research 2008, 4:38 doi:10.1186/1746-6148-4-38

 

The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1746-6148/4/38

 

Received: 3 April 2008 Accepted: 30 September 2008 Published: 30 September 2008

 

© 2008 Jeffrey et al; licensee BioMed Central Ltd.

 

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

Abstract Background The epidemic form of Bovine Spongiform Encephalopathy (BSE) is generally considered to have been caused by a single prion strain but at least two strain variants of cattle prion disorders have recently been recognized. An additional neurodegenerative condition, idiopathic brainstem neuronal chromatolysis and hippocampal sclerosis (IBNC), a rare neurological disease of adult cattle, was also recognised in a sub-set of cattle submitted under the BSE Orders in which lesions of BSE were absent. Between the years of 1988 and 1991 IBNC occurred in Scotland with an incidence of 7 cases per 100,000 beef suckler cows over the age of 6 years.

 

Results When the brains of 15 IBNC cases were each tested by immunohistochemistry, all showed abnormal labelling for prion protein (PrP). Immunohistological labelling for PrP was also present in the retina of a single case available for examination. The pattern of PrP labelling in brain is distinct from that seen in other ruminant prion diseases and is absent from brains with other inflammatory conditions and from normal control brains. Brains of IBNC cattle do not reveal abnormal PrP isoforms when tested by the commercial BioRad or Idexx test kits and do not reveal PrPres when tested by Western blotting using stringent proteinase digestion methods. However, some weakly protease resistant isoforms of PrP may be detected when tissues are examined using mild proteinase digestion techniques.

 

Conclusion The study shows that a distinctive neurological disorder of cattle, which has some clinical similarities to BSE, is associated with abnormal PrP labelling in brain but the pathology and biochemistry of IBNC are distinct from BSE. The study is important either because it raises the possibility of a significant increase in the scope of prion disease or because it demonstrates that widespread and consistent PrP alterations may not be confined to prion diseases. Further studies, including transmission experiments, are needed to establish whether IBNC is a condition in which prion protein is abnormally regulated or it is yet a further example of an infectious cattle prion disease.

 

http://www.biomedcentral.com/1746-6148/4/38

 

1992

 

NEW BRAIN DISORDER

 

3. WHAT ABOUT REPORTS OF NEW FORM OF BSE ?

 

THE VETERINARY RECORD HAS PUBLISHED AN ARTICLE ON A NEW BRAIN DISORDER OF CATTLE DISCOVERED THROUGH OUR CONTROL MEASURES FOR BSE. ALTHOUGH IT PRESENTS SIMILAR CLINICAL SIGNS TO BSE THERE ARE MAJOR DIFFERENCES IN HISTOPATHOLOGY AND INCUBATION PERIODS BETWEEN THE TWO. MUST EMPHASISE THAT THIS IS _NOT_ BSE.

 

4. IS THIS NEW BRAIN DISORDER A THREAT ?

 

WE DO NOT EVEN KNOW WHETHER THE AGENT OF THIS DISEASE IS TRANSMISSIBLE. IN ANY CASE, CASES SO FAR IDENTIFIED HAD SHOWN SIMILAR SYMPTOMS TO THOSE OF BSE, AND THEREFORE HAVE BEEN SLAUGHTERED AND INCINERATED, SO THAT IF A TRANSMISSIBLE AGENT WERE INVOLVED IT WOULD HAVE BEEN ELIMINATED. ...

 

http://collections.europarchive.org/tna/20090114131343/http://www.bseinquiry.gov.uk/files/yb/1992/10/26001001.pdf

 

Tuesday, November 17, 2009

 

SEAC NEW RESULTS ON IDIOPATHIC BRAINSTEM NEURONAL CHROMATOLYSIS (IBNC) FROM THE VETERINARY LABORATORIES AGENCY (VLA) SEAC 103/1

 

http://bse-atypical.blogspot.com/2009/11/seac-new-results-on-idiopathic.html

 

NEW RESULTS ON IDIOPATHIC BRAINSTEM NEURONAL CHROMATOLYSIS

 

"All of the 15 cattle tested showed that the brains had abnormally accumulated PrP"

 

2009

 

http://bse-atypical.blogspot.com/2009/02/new-results-on-idiopathic-brainstem.html

 

''THE LINE TO TAKE'' ON IBNC $$$ 1995 $$$

 

1995

 

page 9 of 14 ;

 

30. The Committee noted that the results were unusual. the questioned whether there could be coincidental BSE infection or contamination with scrapie. Dr. Tyrell noted that the feeling of the committee was that this did not represent a new agent but it was important to be prepared to say something publicly about these findings. A suggested line to take was that these were scientifically unpublishable results but in line with the policy of openness they would be made publicly available and further work done to test their validity. Since the BSE precautions were applied to IBNC cases, human health was protected. Further investigations should be carried out on isolations from brains of IBNC cases with removal of the brain and subsequent handling under strict conditions to avoid the risk of any contamination.

 

31. Mr. Bradley informed the Committee that the CVO had informed the CMO about the IBNC results and the transmission from retina and he, like the Committee was satisfied that the controls already in place or proposed were adequate. ...

 

snip... see full text

 

http://collections.europarchive.org/tna/20080102204938/http://www.bseinquiry.gov.uk/files/yb/1995/06/21005001.pdf

 

http://web.archive.org/web/20030327015011/http://www.bseinquiry.gov.uk/files/yb/1995/06/21005001.pdf

 

Wednesday, July 28, 2010

 

*** Atypical prion proteins and IBNC in cattle DEFRA project code SE1796 FOIA Final report ***

 

http://bse-atypical.blogspot.com/2010/07/atypical-prion-proteins-and-ibnc-in.html

 

IN CONFIDENCE

 

*** BSE ATYPICAL LESION DISTRIBUTION

 

http://web.archive.org/web/20041226015813/http://www.bseinquiry.gov.uk/files/yb/1993/03/14001001.pdf

 

Tuesday, November 02, 2010

 

*** BSE - ATYPICAL LESION DISTRIBUTION (RBSE 92-21367) statutory (obex only) diagnostic criteria CVL 1992

 

http://bse-atypical.blogspot.com/2010/11/bse-atypical-lesion-distribution-rbse.html

 

BSE: BRAIN STEM NEURONAL CHROMATOLYSIS – ‘’BOVINE BRAIN DISORDER’’

 

http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/files/yb/1992/10/23002001.pdf

 

zinc link to cows speculative

 

http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/evidence/yb/1992oct.htm

 

DRAFT IN CONFIDENCE

 

IDIOPATHIC BRAIN STEM NEURONAL CHROMATOLYSIS AND HIPPOCAMPAL SCLEROSIS (Vet. Rec. 1992, M Jeffrey, J W Wilemsith p359-362)

 

http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/files/yb/1992/10/20003001.pdf

 

NEW RESULTS ON IDIOPATHIC BRAINSTEM NEURONAL CHROMATOLYSIS TYPE BSE

 

"All of the 15 cattle tested showed that the brains had abnormally accumulated PrP" 2009 SEAC 102/2

 

http://bse-atypical.blogspot.com/2009/02/new-results-on-idiopathic-brainstem.html

 

Wednesday, October 08, 2008

 

Idiopathic Brainstem Neuronal Chromatolysis (IBNC): a novel prion protein related disorder of cattle?

 

http://bse-atypical.blogspot.com/2008/10/idiopathic-brainstem-neuronal.html

 

Wednesday, May 27, 2015

 

BSE Case Associated with Prion Protein Gene Mutation

 

http://bovineprp.blogspot.com/2015/05/bse-case-associated-with-prion-protein.html

 

BSE: DISCLOSURE OF INFORMATION AND FORECAST

 

http://collections.europarchive.org/tna/20090505194948/http://bseinquiry.gov.uk/files/yb/1992/10/12002001.pdf

 

Thursday, August 15, 2013

 

Stability properties of PrPSc from cattle with experimental transmissible spongiform encephalopathies: use of a rapid whole homogenate, protease-free assay

 

http://transmissiblespongiformencephalopathy.blogspot.com/2013/08/stability-properties-of-prpsc-from.html

 

Thursday, August 15, 2013

 

The emergence of novel BSE prions by serial passages of H-type BSE in bovinized mice

 

http://bse-atypical.blogspot.com/2013/08/the-emergence-of-novel-bse-prions-by.html

 

Monday, September 02, 2013

 

Atypical BSE: role of the E211K prion polymorphism Research Project: TRANSMISSION, DIFFERENTIATION, AND PATHOBIOLOGY OF TRANSMISSIBLE SPONGIFORM ENCEPHALOPATHIES Location: Virus and Prion Research Unit

 

http://bse-atypical.blogspot.com/2013/09/atypical-bse-role-of-e211k-prion.html

 

Sunday, September 1, 2013

 

Evaluation of the Zoonotic Potential of Transmissible Mink Encephalopathy

 

We previously described the biochemical similarities between PrPres derived from L-BSE infected macaque and cortical MM2 sporadic CJD: those observations suggest a link between these two uncommon prion phenotypes in a primate model (it is to note that such a link has not been observed in other models less relevant from the human situation as hamsters or transgenic mice overexpressing ovine PrP [28]). We speculate that a group of related animal prion strains (L-BSE, c-BSE and TME) would have a zoonotic potential and lead to prion diseases in humans with a type 2 PrPres molecular signature (and more specifically type 2B for vCJD)

 

snip...

 

*** Together with previous experiments performed in ovinized and bovinized transgenic mice and hamsters [8,9] indicating similarities between TME and L-BSE, the data support the hypothesis that L-BSE could be the origin of the TME outbreaks in North America and Europe during the mid-1900s.

 

http://transmissiblespongiformencephalopathy.blogspot.com/2013/09/evaluation-of-zoonotic-potential-of.html

 

PLEASE note, most important ;

 

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

 

PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS

 

THANK YOU PRION 2015 TAYLOR & FRANCIS, Professor Chernoff, and Professor Aguzzi et al, for making these PRION 2015 Congressional Poster and Oral Abstracts available freely to the public. ...Terry S. Singeltary Sr.

 

O.05: Transmission of prions to primates after extended silent incubation periods: Implications for BSE and scrapie risk assessment in human populations

 

Emmanuel Comoy, Jacqueline Mikol, Val erie Durand, Sophie Luccantoni, Evelyne Correia, Nathalie Lescoutra, Capucine Dehen, and Jean-Philippe Deslys Atomic Energy Commission; Fontenay-aux-Roses, France

 

Prion diseases (PD) are the unique neurodegenerative proteinopathies reputed to be transmissible under field conditions since decades. The transmission of Bovine Spongiform Encephalopathy (BSE) to humans evidenced that an animal PD might be zoonotic under appropriate conditions. Contrarily, in the absence of obvious (epidemiological or experimental) elements supporting a transmission or genetic predispositions, PD, like the other proteinopathies, are reputed to occur spontaneously (atpical animal prion strains, sporadic CJD summing 80% of human prion cases). Non-human primate models provided the first evidences supporting the transmissibiity of human prion strains and the zoonotic potential of BSE. Among them, cynomolgus macaques brought major information for BSE risk assessment for human health (Chen, 2014), according to their phylogenetic proximity to humans and extended lifetime. We used this model to assess the zoonotic potential of other animal PD from bovine, ovine and cervid origins even after very long silent incubation periods. We recently observed the direct transmission of a natural classical scrapie isolate to macaque after a 10-year silent incubation period, with features similar to some reported for human cases of sporadic CJD, albeit requiring fourfold longe incubation than BSE. Scrapie, as recently evoked in humanized mice (Cassard, 2014), is the third potentially zoonotic PD (with BSE and L-type BSE), ***thus questioning the origin of human sporadic cases. We will present an updated panorama of our different transmission studies and discuss the implications of such extended incubation periods on risk assessment of animal PD for human health.

 

===============

 

***thus questioning the origin of human sporadic cases...TSS

 

===============

 

O.08: H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism: Clinical and pathologic features in wild-type and E211K cattle following intracranial inoculation

 

S Jo Moore, M Heather West Greenlee, Jodi Smith, Eric Nicholson, Cathy Vrentas, and Justin Greenlee United States Department of Agriculture; Ames, IA USA

 

In 2006 an H-type bovine spongiform encephalopathy (BSE) case was reported in an animal with an unusual polymorphism (E211K) in the prion protein gene. Although the prevalence of this polymorphism is low, cattle carrying the K211 allele are predisposed to rapid onset of H-type BSE when exposed. The purpose of this study was to investigate the phenotype of this BSE strain in wild-type (E211E) and E211K heterozygous cattle. One calf carrying the wild-type allele and one E211K calf were inoculated intracranially with H-type BSE brain homogenate from the US 2006 case that also carried one K211 allelle. In addition, one wild-type calf and one E211K calf were inoculated intracranially with brain homogenate from a US 2003 classical BSE case. All animals succumbed to clinical disease. Survival times for E211K H-type BSE inoculated catttle (10 and 18 months) were shorter than the classical BSE inoculated cattle (both 26 months). Significant changes in retinal function were observed in H-type BSE challenged cattle only. Animals challenged with the same inoculum showed similar severity and neuroanatomical distribution of vacuolation and disease-associated prion protein deposition in the brain, though differences in neuropathology were observed between E211K H-type BSE and classical BSE inoculated animals. Western blot results for brain tissue from challenged animals were consistent with the inoculum strains. ***This study demonstrates that the phenotype of E211K H-type BSE remains stable when transmitted to cattle without the E211K polymorphism, and exhibits a number of features that differ from classical BSE in both wild-type and E211K cattle.

 

==============

 

***This study demonstrates that the phenotype of E211K H-type BSE remains stable when transmitted to cattle without the E211K polymorphism, and exhibits a number of features that differ from classical BSE in both wild-type and E211K cattle.***

 

PLEASE SEE ;

 

Wednesday, May 27, 2015

 

BSE Case Associated with Prion Protein Gene Mutation

 

http://bovineprp.blogspot.com/2015/05/bse-case-associated-with-prion-protein.html

 

==============

 

P.108: Successful oral challenge of adult cattle with classical BSE

 

Sandor Dudas1,*, Kristina Santiago-Mateo1, Tammy Pickles1, Catherine Graham2, and Stefanie Czub1 1Canadian Food Inspection Agency; NCAD Lethbridge; Lethbridge, Alberta, Canada; 2Nova Scotia Department of Agriculture; Pathology Laboratory; Truro, Nova Scotia, Canada

 

Classical Bovine spongiform encephalopathy (C-type BSE) is a feed- and food-borne fatal neurological disease which can be orally transmitted to cattle and humans. Due to the presence of contaminated milk replacer, it is generally assumed that cattle become infected early in life as calves and then succumb to disease as adults.

 

Here we challenged three 14 months old cattle per-orally with 100 grams of C-type BSE brain to investigate age-related susceptibility or resistance. During incubation, the animals were sampled monthly for blood and feces and subjected to standardized testing to identify changes related to neurological disease.

 

At 53 months post exposure, progressive signs of central nervous system disease were observed in these 3 animals, and they were euthanized. Two of the C-BSE animals tested strongly positive using standard BSE rapid tests, however in 1 C-type challenged animal, Prion 2015 Poster Abstracts S67 PrPsc was not detected using rapid tests for BSE. Subsequent testing resulted in the detection of pathologic lesion in unusual brain location and PrPsc detection by PMCA only.

 

Our study demonstrates susceptibility of adult cattle to oral transmission of classical BSE. We are further examining explanations for the unusual disease presentation in the third challenged animal.

 

========================

 

***Our study demonstrates susceptibility of adult cattle to oral transmission of classical BSE. ***

 

P.86: Estimating the risk of transmission of BSE and scrapie to ruminants and humans by protein misfolding cyclic amplification

 

Morikazu Imamura, Naoko Tabeta, Yoshifumi Iwamaru, and Yuichi Murayama National Institute of Animal Health; Tsukuba, Japan

 

To assess the risk of the transmission of ruminant prions to ruminants and humans at the molecular level, we investigated the ability of abnormal prion protein (PrPSc) of typical and atypical BSEs (L-type and H-type) and typical scrapie to convert normal prion protein (PrPC) from bovine, ovine, and human to proteinase K-resistant PrPSc-like form (PrPres) using serial protein misfolding cyclic amplification (PMCA).

 

Six rounds of serial PMCA was performed using 10% brain homogenates from transgenic mice expressing bovine, ovine or human PrPC in combination with PrPSc seed from typical and atypical BSE- or typical scrapie-infected brain homogenates from native host species. In the conventional PMCA, the conversion of PrPC to PrPres was observed only when the species of PrPC source and PrPSc seed matched. However, in the PMCA with supplements (digitonin, synthetic polyA and heparin), both bovine and ovine PrPC were converted by PrPSc from all tested prion strains. On the other hand, human PrPC was converted by PrPSc from typical and H-type BSE in this PMCA condition.

 

Although these results were not compatible with the previous reports describing the lack of transmissibility of H-type BSE to ovine and human transgenic mice, ***our findings suggest that possible transmission risk of H-type BSE to sheep and human. Bioassay will be required to determine whether the PMCA products are infectious to these animals.

 

================

 

***our findings suggest that possible transmission risk of H-type BSE to sheep and human. ***

 

ALSO, PLEASE SEE ;

 

31 Jan 2015 at 20:14 GMT

 

*** Ruminant feed ban for cervids in the United States? ***

 

31 Jan 2015 at 20:14 GMT

 

http://www.plosone.org/annotation/listThread.action?root=85351

 

http://chronic-wasting-disease.blogspot.com/

 

Saturday, May 30, 2015

 

PRION 2015 ORAL AND POSTER CONGRESSIONAL ABSTRACTS

 

https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf

 

http://transmissiblespongiformencephalopathy.blogspot.com/2015/05/prion-2015-oral-and-poster.html

 

Wednesday, June 10, 2015

 

Zoonotic Potential of CWD Prions

 

LATE-BREAKING ABSTRACTS

 

http://chronic-wasting-disease.blogspot.com/2015/06/zoonotic-potential-of-cwd-prions.html

 

please see attached pdf file, with references of breaches in the USA triple BSE mad cow firewalls, and recent science on the TSE prion disease. ...TSS No documents available. Attachments View All (1) Docket No. APHIS-2014-0107 Bovine Spongiform Encephalopathy; Importation of Animals and Animal Products Singeltary Submission View Attachment:

 

 http://www.regulations.gov/#!documentDetail;D=APHIS-2014-0107-0003

 

Thursday, May 28, 2015

 

OIE cuts six European countries' mad cow risk level, while increasing risk factors for humans to the BSE TSE PRION DISEASE around the globe

 

http://bovineprp.blogspot.com/2015/05/oie-cuts-six-european-countries-mad-cow.html

 

COOL H.R. 2393 Agriculture Chairman K. Michael Conaway (R-TX) Fears of US imports infected with mad cow disease is emerging as an issue in trans-Pacific trade talks

 

Posted by Terry S. Singeltary Sr. on May 20, 2015 at 9:00am

 

http://justgroundsonline.com/profiles/blogs/cool-h-r-2393-agriculture-chairman-k-michael-conaway-r-tx-fears?xg_source=msg_appr_blogpost

 

Sunday, June 14, 2015

 

Larry’s Custom Meats Inc. Recalls Beef Tongue Products That May Contain Specified Risk Materials BSE TSE Prion

 

http://madcowusda.blogspot.com/2015/06/larrys-custom-meats-inc-recalls-beef.html

 

spontaneous atypical BSE ???

 

if that's the case, then France is having one hell of an epidemic of atypical BSE, probably why they stopped testing for BSE, problem solved $$$

 

As of December 2011, around 60 atypical BSE cases have currently been reported in 13 countries, *** with over one third in France.

 

http://www.biomedcentral.com/1746-6148/8/74

 

so 20 cases of atypical BSE in France, compared to the remaining 40 cases in the remaining 12 Countries, divided by the remaining 12 Countries, about 3+ cases per country, besides Frances 20 cases. you cannot explain this away with any spontaneous BSe. ...TSS

 

Sunday, October 5, 2014

 

France stops BSE testing for Mad Cow Disease

 

http://transmissiblespongiformencephalopathy.blogspot.com/2014/10/france-stops-bse-testing-for-mad-cow.html

 

Thursday, July 24, 2014

 

*** Protocol for further laboratory investigations into the distribution of infectivity of Atypical BSE SCIENTIFIC REPORT OF EFSA New protocol for Atypical BSE investigations

 

 http://bse-atypical.blogspot.com/2014/07/protocol-for-further-laboratory.html

 

Subject: FATEPriDE Environmental Factors that Affect the Development of Prion Diseases

 

Date: February 18, 2006 at 9:24 am PST

 

FATEPriDE

 

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

 

Duration

 

36 months plus 6 month extension

 

Partners

 

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

 

Introduction

 

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.

 

Objectives

 

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.

 

http://www.arp-manchester.org.uk/FatePride.htm

 

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.

 

References

 

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.

 

http://europa.eu.int/comm/food/fs/sc/ssc/out356_en.pdf

 

FATEPRIDE

 

http://www.arpmanchester.org.uk/documents/FINALDetailedProgrammeandAbstracts.pdf

 

ITEM 6 FATEPRIDE (SEAC 97/4) 35.

 

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.

 

http://www.seac.gov.uk/papers/draft98-1.pdf

 

Subject: FATEPriDE KEY FINDINGS ORGANOPHOSPHATE NO RELATIONSHIP TO CAUSE TSE Date: May 3, 2007 at 8:41 am PST

 

KEY FINDINGS

 

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.

 

snip...

 

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.__

 

snip...

 

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.

 

http://www.seac.gov.uk/papers/97-4.pdf

 

OP'S MEETING WITH PURDEY

 

http://web.archive.org/web/20010614051238/http://www.bseinquiry.gov.uk/files/yb/1994/02/09001001.pdf

 

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.

 

http://www.neuroreport.com/

 

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.

 

References 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.

 

 http://europa.eu.int/comm/food/fs/sc/ssc/out356_en.pdf

 

UK FARMER WITH BSE (personal communication)

 

1) None of our animals that contracted BSE were treated with OP's, even in utero. 2) My kids were treated with OP's as infants to control head lice. This seems to be endemic as infection waves in UK primary schools (and possibly elsewhere). 3) One might argue if the continued use of british beef in the UK was ethical, none the less it happened. We have a duty to learn from it, not least a duty to learn on behalf of those people who died so horribly....

 

============end...tss===========

 

However, i have never dusputed the remote possibility that ;

 

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.

 

http://www.neuroreport.com/pt/re/neuroreport/abstract.00001756-199805110-00026.htm;jsessionid=D3XI1RSXL8uyd5FtR23dvWP1753t5Cv0lY8VXIid8eyvzvuM7qJ5!-477899252!-949856144!90011index=1&database=ppvovft&results=1&count=10&searchid=1&nav=search

 

Copper deficiency in the young bovine results in dramatic decreases in brain copper concentration ***but does not alter brain prion protein biology

 

L. R. Legleiter, J. W. Spears and H. C. Liu Department of Animal Science and Interdepartmental Nutrition Program, North Carolina State University, Raleigh, NC

 

Jerry_Spears@ncsu.edu

 

Abstract

 

A manganese (Mn) for copper (Cu) substitution on cellular prion proteins (PrPc) in the brain that results in biochemical changes to PrPc has been implicated in the pathogenesis of transmissible spongiform encephalopathies. Recent research in the mature bovine does _NOT_ support this theory. The present study tested this hypothesis using progeny from gestating cows receiving Cu-deficient diets or Cu-deficient diets coupled with high dietary Mn. Copper-adequate cows (n = 39) were assigned randomly to treatments: 1) control (adequate in Cu and Mn), 2) Cu-deficient (-Cu), and 3) Cu-deficient plus high dietary Mn (-Cu Mn). Cows assigned to treatments -Cu and -Cu Mn received no supplemental Cu and were supplemented with molybdenum (Mo) to further induce Cu deficiency. The -Cu Mn treatment also received 500 mg supplemental Mn/kg dietary DM. Calves were weaned at 180 d and maintained on the same treatments as their respective dams for 260 d. Copper-deficient calves (-Cu and -Cu Mn) had decreased (P = 0.001) brain (obex) Cu and tended to have increased (P = 0.09) obex Mn relative to controls. Obex Mn/Cu ratios were substantially increased (P < 0.001) in calves receiving -Cu and -Cu Mn treatments compared to controls and were higher (P < 0.001) in -Cu Mn calves than in -Cu calves. Obex prion protein characteristics, including proteinase K degradability, superoxide dismutase (SOD)-like activity, and glycoform distributions, were largely unaffected. Obex tissue antioxidant capacity was not compromised by perturbations in brain metals, but Cu-deficient calves tended to have decreased (P = 0.06) Cu/Zn SOD activity and increased (P = 0.06) Mn SOD activity. Although obex copper was decreased due to Cu deficiency and Mn increased due to exposure to high dietary Mn, the obex metal imbalance had minimal effects on PrPc functional characteristics in the calves.

 

http://jas.fass.org/cgi/content/abstract/jas.2007-0403v1

 

2015

 

P.46: Mitigation of prion infectivity and conversion capacity by a simulated natural process—repeated cycles of drying and wetting

 

Qi Yuan2,*, Thomas Eckland2, Glenn Telling3, Jason Bartz2, and Shannon Bartelt-Hunt1 1University of Nebraska-Lincoln; Omaha, NE, USA; 2Creighton University; Omaha, NE, USA; 3Colorado State University; Fort Collins, CO, USA

 

Prions enter the environment from infected hosts, bind to a wide range of soil and soil minerals, and remain highly infectious. Environmental sources of prions almost certainly contribute to the transmission of chronic wasting disease in cervids and scrapie in sheep and goats. While much is known about the introduction of prions into the environment and their interaction with soil, relatively little is known about prion degradation and inactivation by natural environmental processes. In this study, we examined the effect of repeated cycles of drying and wetting on prion fitness and determined that 10 cycles of repeated drying and wetting could reduce PrPSc abundance, PMCA amplification efficiency and extend the incubation period of disease. Importantly, prions bound to soil were more susceptible Prion 2015 Poster Abstracts S35 to inactivation by repeated cycles of drying and wetting compared to unbound prions, a result which may be due to conformational changes in soil-bound PrPSc or consolidation of the bonding between PrPSc and soil. This novel finding demonstrates that naturallyoccurring environmental process can degrade prions.

 

==========

 

P.66: Transport of CWD prions in Alberta soils

 

Alsu Kuznetsova1, Debbie McKenzie2, Tariq Siddique1, and Judd Aiken2 1University of Alberta; Department of Renewable Resources; Edmonton, Canada; 2University of Alberta; Centre for Prions and Protein Folding Diseases; Edmonton, Canada

 

The transmission of chronic wasting disease (CWD) includes environmental pathways, particularly soils as disease reservoirs. Soils differ dramatically in their capacity to adsorb PrPCWD due to differences in mineral composition, humus content and particle surface area. Mineral and organic compounds have the ability to bind PrPCWD impacting infectious properties. The extreme variability of these soil constituents suggests that the PrPCWD fate and behavior will depend on specific soil properties. The soil moisture regime also has the potential to affect transportation of compounds through a soil profile. PrPCWD can be bound to soil particles with Prion 2015 Poster Abstracts S45 3 hypothetical scenarios for prion fate: (i) prions stay in the surface soil horizon and remain bioavailable for grazing animals; (ii) prions can be transported into lower soil horizons and become unavailable for consumption; or (iii) prions can migrate through the soil profile and end up in ground water. We performed bench-scale experiments with soil columns to evaluate the potential for transportation of PrPCWD using soils from different regions of Alberta, Canada. The Luvisols found in northern Alberta have an ustic/udic moisture regime and illite as a predominant clay mineral. The prion binding capacity of illite is poor suggesting it cannot contribute to prion binding and PrPCWD can migrate through the soil profile. Chernozems are found in the CWD-endemic region in southern Alberta and have an aridic soil moisture regime, high amount of humus content and contain montmorillonite. In the Chernozem soil columns PrPCWD remains on the soil surface and does not migrate in lower horizons.

 

========

 

P.161: Prion soil binding may explain efficient horizontal CWD transmission

 

Nathaniel Denkers1, Davin Henderson1, Shannon Bartelt-Hunt2, Jason Bartz3, and Edward Hoover1 1Colorado State University; Fort Collins, Colorado USA; 2University of Nebraska-Lincoln; Omaha, Nebraska USA; 3Creighton University; Omaha, Nebraska USA

 

Background. Chronic wasting disease (CWD) is unique due to the facile spread in nature. The interaction of excreted CWD prions and soil is a hypothesized contributor in environmental transmission. The present study examines whether and to what degree CWD prions bind to silty clay loam (SCL) using an adapted version of real-time quaking-induced conversion (RT-QuIC) methodology.

 

Materials and Methods. Varying amounts (50–3.12 mg) of SCL were incubated with 1 mL-serial dilutions of CWD (C), CWD (¡), or no brain homogenate (BH). Samples were centrifuged, washed, diluted 1:10 in 0.1% SDS, and 2.5 uL seeded in RT-QuIC assays employing recombinant Syrian hamster prion PrP substrate. Multiple well replicates of sample and supernatant fractions were assayed for positive seeding activity (recorded as thioflavin T fluorescence emission; 480 nm). Samples were considered positive if they crossed a threshold of 25,000. Reaction rates (RR) were calculated, averaged, and expressed as 1/RR. Results. Positive seeding activity was detected for most SCL samples incubated with CWD (C) BH dilutions. Higher SCL concentrations (50 mg) produced low fluorescent readings due to optical interference. Lower SCL concentrations (6.25 mg) produced minimal optical interference and removed the vast majority of seeding activity from CWDC BH in a concentration-dependent manner; determined by seeding activity in residual BH supernatants. Control SCL and supernatants produced minimal falsepositive reactions (8 of 240 replicates; 3.3%). We estimated the prion binding capacity of SCL to be 0.16 ng/mg.

 

Conclusion. Silty clay loam exhibits highly efficient prion binding, inferring a durable environmental reservoir, and an efficient mechanism for indirect horizontal CWD transmission.

 

https://prion2015.files.wordpress.com/2015/05/prion2015abstracts.pdf

 

Saturday, March 15, 2014

 

Potential role of soil properties in the spread of CWD in western Canada

 

http://chronic-wasting-disease.blogspot.com/2014/03/potential-role-of-soil-properties-in.html

 

http://chronic-wasting-disease.blogspot.com/2012/09/resistance-of-soil-bound-prions-to.html

 

http://scrapie-usa.blogspot.com/2011/02/environmental-sources-of-scrapie-prions.html

 

http://chronic-wasting-disease.blogspot.com/2010/08/select-tissue-mineral-concentrations.html

 

Tuesday, June 23, 2015

 

Report on the monitoring and testing of ruminants for the presence of transmissible spongiform encephalopathies (TSEs) in the EU in 2013 Final version 18 May 2015

 

http://transmissiblespongiformencephalopathy.blogspot.com/2015/06/report-on-monitoring-and-testing-of.html

 

 

end...TSS