Bovine adapted transmissible mink encephalopathy is similar to L-BSE after passage through sheep with the VRQ/VRQ genotype but not VRQ/ARQ
Published: 08 October 2020
Bovine adapted transmissible mink encephalopathy is similar to L-BSE after passage through sheep with the VRQ/VRQ genotype but not VRQ/ARQ
Eric Cassmann, Sarah Jo Moore, Robyn Kokemuller, Anne Balkema-Buschmann, Martin Groschup, Eric Nicholson & Justin Greenlee BMC Veterinary Research volume 16, Article number: 383 (2020
Abstract Background Transmissible mink encephalopathy (TME) is a fatal neurologic disease of farmed mink. Evidence indicates that TME and L-BSE are similar and may be linked in some outbreaks of TME. We previously transmitted bovine adapted TME (bTME) to sheep. The present study compared ovine passaged bTME (o-bTME) to C-BSE and L-BSE in transgenic mice expressing wild type bovine prion protein (TgBovXV). To directly compare the transmission efficiency of all prion strains in this study, we considered the attack rates and mean incubation periods. Additional methods for strain comparison were utilized including lesion profiles, fibril stability, and western blotting.
Results Sheep donor genotype elicited variable disease phenotypes in bovinized mice. Inoculum derived from a sheep with the VRQ/VRQ genotype (o-bTMEVV) resulted in an attack rate, incubation period, western blot profile, and neuropathology most similar to bTME and L-BSE. Conversely, donor material from a sheep with the VRQ/ARQ genotype (o-bTMEAV) elicited a phenotype distinct from o-bTMEVV, bTME and L-BSE. The TSE with the highest transmission efficiency in bovinized mice was L-BSE. The tendency to efficiently transmit to TgBovXV mice decreased in the order bTME, C-BSE, o-bTMEVV, and o-bTMEAV. The transmission efficiency of L-BSE was approximately 1.3 times higher than o-bTMEVV and 3.2 times higher than o-bTMEAV.
Conclusions Our findings provide insight on how sheep host genotype modulates strain genesis and influences interspecies transmission characteristics. Given that the transmission efficiencies of L-BSE and bTME are higher than C-BSE, coupled with previous reports of L-BSE transmission to mice expressing the human prion protein, continued monitoring for atypical BSE is advisable in order to prevent occurrences of interspecies transmission that may affect humans or other species.
Snip...
Conclusions Various factors including TSE agent, interspecies transmission, and sheep donor genotype can influence the transmission efficiency and disease phenotype in this bovine model. In this case, the western blot and lesion profiles of o-bTMEAV differed greatly from o-bTMEVV, bTME, and L-BSE. The lesion profile, PrPSc patterns, and western blot similarities between L-BSE, bTME, and o-bTMEVV support the hypothesis of a common origin for these prion strains. Previous work has shown that the Stetsonville, WI outbreak of TME could have been precipitated by feeding mink a downer cow with atypical BSE; therefore, it very well may have originated from a cow with L-BSE. The agent of TME appears to remain stable, and it has a high transmission efficiency after a sequence of interspecies transmission events. Although C-BSE is the archetypal foodborne TSE, our findings indicate that L-BSE and bTME have greater transmission efficiencies in bovinized mice. Previous work has demonstrated that L-BSE also is more virulent than C-BSE in mice expressing the human prion protein [46, 55]. Although the documented incidence of L-BSE is low, the propensity of L-BSE and the TME agent to cross species barriers support the continued monitoring for atypical BSE.
WEDNESDAY, NOVEMBER 20, 2019
Sheep Are Susceptible to the Bovine Adapted Transmissible Mink Encephalopathy agent by Intracranial Inoculation and Have Evidence of Infectivity in Lymphoid Tissues
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
49. The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
E. D. Cassmanna,b, S. J. Moorea,b, R. D. Kokemullera, A. Balkema-Buschmannc, M. H. Groschupcand J. J. Greenleea
aVirus and Prion Research Unit, National Animal Disease Center, ARS, United States Department of Agriculture, Ames, IA, USA (EDC, SJM, RDK, JJG); bOak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the U.S. Department of Energy (DOE) and the U.S. Department of Agriculture (USDA). ORISE is managed by ORAU under DOE contract number DE-SC0014664. (EDC, SJM), Department of Veterinary Pathology, Iowa State University, Ames, IA, USA (JDS); cInstitute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald – Isle of Riems, Germany (ABB, MHG)
CONTACT E. D. Cassmann eric.cassmann@usda.gov
ABSTRACT
Introduction: Transmissible mink encephalopathy (TME) is a fatal neurologic prion disease of farmed mink. Epidemiologic and experimental evidence following a Wisconsin outbreak in 1985 has linked TME to low-type bovine spongiform encephalopathy (BSE-L). Evidence suggests that farmed mink were likely exposed through feeding of BSE-L infected downer cattle. The interspecies transmission of TME to cattle has been documented. Recently, we demonstrated the susceptibility of sheep to cattle passaged TME by intracranial inoculation. The aim of the present study was to compare ovine passaged cattle TME to other prion diseases of food-producing animals. Using a bovine transgenic mouse model, we compared the disease phenotype of sheep TME to BSE-C and BSE-L.
Materials and Methods: Separate inoculants of sheep passaged TME were derived from animals with the VRQ/VRQ (VV136) and ARQ/VRQ (AV136) prion protein genotype. Transgenic bovinized mice (TgBovXV) were intracranially inoculated with 20 µl of 1% w/v brain homogenate. The disease phenotypes were characterized by comparing the attack rates, incubation periods, and vacuolation profiles in TgBovXV mice.
Results: The attack rate for BSE-C (13/13), BSE-L (18/18), and TMEVV (21/21) was 100%; whereas, the TMEAV group (15/19) had an incomplete attack rate. The average incubation periods were 299, 280, 310, and 541 days, respectively. The vacuolation profiles of BSE-L and TMEVV were most similar with mild differences observed in the thalamus and medulla. Vacuolation profiles from the BSE-C and TMEAV experimental groups were different than TMEVVand BSE-L.
Conclusion: Overall the phenotype of disease in TME inoculated transgenic mice was dependent on the sheep donor genotype (VV vs AV). The results of the present study indicate that TME isolated from VRQ/VRQ sheep is similar to BSE-L with regards to incubation period, attack rate, and vacuolation profile. Our findings are in agreement with previous research that found phenotypic similarities between BSE-L and cattle passaged TME in an ovine transgenic rodent model. In this study, the similarities between ovine TME and BSE-L are maintained after multiple interspecies passages.
Prion2019 Conference
2007
August 1988
Evidence That Transmissible Mink Encephalopathy Results From Feeding Infected Cattle
Evidence That Transmissible Mink Encephalopathy Results from Feeding Infected Cattle Over the next 8-10 weeks, approximately 40% of all the adult mink on the farm died from TME. snip... The rancher was a ''dead stock'' feeder using mostly (>95%) downer or dead dairy cattle...
NOW, in 1979, it was proven that indeed U.S. scrapie strain that was transmitted to U.S. cattle, did NOT produce a Transmissible Spongiform Encephalopathy (TSE) like the U.K. B.S.E., but a TSE unlike the U.K. B.S.E. SO what does all this tell us? it tells me that there is a possibility that a strain of mad cow disease was circulating in the U.S.A. long, long, before originally thought, only left to be ignored, while incubating and spreading.
3.57 The experiment which might have determined whether BSE and scrapie were caused by the same agent (ie, the feeding of natural scrapie to cattle) was never undertaken in the UK. It was, however, performed in the USA in 1979, when it was shown that cattle inoculated with the scrapie agent endemic in the flock of Suffolk sheep at the United States Department of Agriculture in Mission, Texas, developed a TSE quite unlike BSE.339 The findings of the initial transmission, though not of the clinical or neurohistological examination, were communicated in October 1988 to Dr Watson, Director of the CVL, following a visit by Dr Wrathall, one of the project leaders in the Pathology Department of the CVL, to the United States Department of Agriculture.340 The results were not published at this point, since the attempted transmission to mice from the experimental cow brain had been inconclusive. The results of the clinical and histological differences between scrapie-affected sheep and cattle were published in 1995. Similar studies in which cattle were inoculated intracerebrally with scrapie inocula derived from a number of scrapie-affected sheep of different breeds and from different States, were carried out at the US National Animal Disease Centre.341 The results, published in 1994, showed that this source of scrapie agent, though pathogenic for cattle, did not produce the same clinical signs of brain lesions characteristic of BSE.
3.58 There are several possible reasons why the experiment was not performed in the UK. It had been recommended by Sir Richard Southwood (Chairman of the Working Party on Bovine Spongiform Encephalopathy) in his letter to the Permanent Secretary of MAFF, Mr (now Sir) Derek Andrews, on 21 June 1988,342 though it was not specifically recommended in the Working Party Report or indeed in the Tyrrell Committee Report (details of the Southwood Working Party and the Tyrell Committee can be found in vol. 4: The Southwood Working Party, 1988–89 and vol. 11: Scientists after Southwood respectively). The direct inoculation of scrapie into calves was given low priority, because of its high cost and because it was known that it had already taken place in the USA.343 It was also felt that the results of such an experiment would be hard to interpret. While a negative result would be informative, a positive result would need to demonstrate that when scrapie was transmitted to cattle, the disease which developed in cattle was the same as BSE.344 Given the large number of strains of scrapie and the possibility that BSE was one of them, it would be necessary to transmit every scrapie strain to cattle separately, to test the hypothesis properly. Such an experiment would be expensive. Secondly, as measures to control the epidemic took hold, the need for the experiment from the policy viewpoint was not considered so urgent. It was felt that the results would be mainly of academic interest.345
3.59 Nevertheless, from the first demonstration of transmissibility of BSE in 1988, the possibility of differences in the transmission properties of BSE and scrapie was clear. Scrapie was transmissible to hamsters, but by 1988 attempts to transmit BSE to hamsters had failed. Subsequent findings increased that possibility.
337 Fraser, H., Bruce, M., Chree, A., McConnell, I. and Wells, G. (1992) Transmission of Bovine Spongiform Encephalopathy and Scrapie to Mice, Journal of General Virology, 73, 1891–7; Bruce, M., Chree, A., McConnell, I., Foster, J., Pearson, G. and Fraser, H. (1994) Transmission of Bovine Spongiform Encephalopathy and Scrapie to Mice: Strain Variation and the Species Barrier, Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences, 343, 405–11 338 Bruce, M., Will, R., Ironside, J., McConell, I., Drummond, D., Suttie, A., McCordie, L., Chree, A., Hope, J., Birkett, C., Cousens, S., Fraser, H. and Bostock, C. (1997) Transmissions to Mice Indicate that ‘New Variant’ CJD is Caused by the BSE Agent, Nature, 389, 498–501 339 Clark, W., Hourrigan, J. and Hadlow, W. (1995) Encephalopathy in Cattle Experimentally Infected with the Scrapie Agent, American Journal of Veterinary Research, 56, 606–12 340 YB88/10.00/1.1 341 Cutlip, R., Miller, J., Race, R., Jenny, A., Katz, J., Lehmkuhl, H., Debey, B. and Robinson, M. (1994) Intracerebral Transmission of Scrapie to Cattle, Journal of Infectious Diseases, 169, 814–20 342 YB88/6.21/1.2 343 YB88/11.17/2.4
31
Appendix I VISIT TO USA - OR A E WRATHALL — INFO ON BSE AND SCRAPIE
Dr Clark lately of the scrapie Research Unit, Mission Texas has
successfully transmitted ovine and caprine scrapie to cattle. The
experimental results have not been published but there are plans to do
this. This work was initiated in 1978. A summary of it is:-
Expt A 6 Her x Jer calves born in 1978 were inoculated as follows with
a 2nd Suffolk scrapie passage:-
i/c 1ml; i/m, 5ml; s/c 5ml; oral 30ml.
1/6 went down after 48 months with a scrapie/BSE-like disease.
Expt B 6 Her or Jer or HxJ calves were inoculated with angora Goat
virus 2/6 went down similarly after 36 months.
Expt C Mice inoculated from brains of calves/cattle in expts A & B were resistant, only 1/20 going down with scrapie and this was the reason given for not publishing.
Diagnosis in A, B, C was by histopath. No reports on SAF were given.
Dr Warren Foote indicated success so far in eliminating scrapie in offspring from experimentally— (and naturally) infected sheep by ET. He had found difficulty in obtaining embryos from naturally infected sheep (cf SPA).
Prof. A Robertson gave a brief accout of BSE. The us approach was to
32
accord it a very low profile indeed. Dr A Thiermann showed the picture in the "Independent" with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs.
BSE was not reported in USA.
4. Scrapie incidents (ie affected flocks) have shown a dramatic increase since 1978. In 1953 when the National Control scheme was started there were 10-14 incidents, in 1978 - 1 and in 1988 so far 60.
5. Scrapie agent was reported to have been isolated from a solitary fetus.
6. A western blotting diagnostic technique (? on PrP) shows some promise.
7. Results of a questionnaire sent to 33 states on the subject of the national sheep scrapie programme survey indicated
17/33 wished to drop it
6/33 wished to develop it
8/33 had few sheep and were neutral
Information obtained from Dr Wrathall‘s notes of a meeting of the u.s.
Animal Health Association at Little Rock, Arkansas Nov. 1988.
33
In Confidence - Perceptions of unconventional slow virus diseases of animals in the USA - APRIL-MAY 1989 - G A H Wells
3. Prof. A. Robertson gave a brief account of BSE. The US approach was to accord it a very low profile indeed. Dr. A Thiermann showed the picture in the ''Independent'' with cattle being incinerated and thought this was a fanatical incident to be avoided in the US at all costs. ...
VISIT TO USA - DR AE WRATHALL - INFO ON BSE AND SCRAPIE
1. Dr. Clark lately of the Scrapie Research Unit, Mission Texas has successfully transmitted ovine & caprine Scrapie to cattle. The experimental results have not been published but there are plans to do this. This work was initiated in 1978. A summary of it is;
snip...see handwritten notes from this here;
IN CONFIDENCE
Perceptions of an unconventional slow virus diseases of animals in the U.S.A. G A H Wells
Report of a Visit to the USA April-May 1989
Thursday, June 09, 2016
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base Scrapie Experiment 1964
How Did CWD Get Way Down In Medina County, Texas?
Confucius ponders...
Could the Scrapie experiments back around 1964 at Moore Air Force near Mission, Texas, could this area have been ground zero for CWD TSE Prion (besides the CWD cases that have waltzed across the Texas, New Mexico border near WSMR Trans Pecos region since around 2001)?
Epidemiology of Scrapie in the United States 1977
snip...
Scrapie Field Trial Experiments Mission, Texas A Scrapie Field Trial was developed at Mission, Texas, to provide additional information for the eradication program on the epidemiology of natural scrapie. The Mission Field Trial Station is located on 450 acres of pastureland, part of the former Moore Air Force Base, near Mission, Texas.
It was designed to bring previously exposed, and later also unexposed, sheep or goats to the Station and maintain and breed them under close observation for extended periods to determine which animals would develop scrapie and define more closely the natural spread and other epidemiological aspects of the disease.
The 547 previously exposed sheep brought to the Mission Station beginning in 1964 were of the Cheviot, Hampshire, Montadale, or Suffolk breeds.
They were purchased as field outbreaks occurred, and represented 21 bloodlines in which scrapie had been diagnosed.
Upon arrival at the Station, the sheep were maintained on pasture, with supplemental feeding as necessary.
The station was divided into 2 areas:
(1) a series of pastures and-pens occupied by male animals only, and
(2) a series of pastures and pens occupied by females and young progeny of both sexes.
... snip...
see full text ;
Thursday, June 09, 2016
Scrapie Field Trial Experiments Mission, Texas, The Moore Air Force Base Scrapie TSE Prion Experiment 1964 How Did CWD Get Way Down In Medina County, Texas?
doi:10.1016/S0021-9975(97)80022-9 Copyright © 1997 Published by Elsevier Ltd.
Second passage of a US scrapie agent in cattle
R.C. Cutlip, J.M. Miller and H.D. Lehmkuhl
United States Department of Agriculture, Agricultural Research Service, National Animal Disease Center, Ames, Iowa, USA
Received 10 September 1996; accepted 31 July 1997. Available online 25 May 2006.
Summary
Scrapie and bovine spongiform encephalopathy are similar chronic neurodegenerative diseases of sheep and cattle. An earlier study showed that, on first passage in cattle, a US scrapie agent caused an encephalopathy that was distinct from bovine spongiform encephalopathy (BSE). The present report describes a second passage in cattle, carried out because diseases caused by the spongiform encephalopathy agents often change in character with additional passages in abnormal hosts. For this work, young calves were inoculated intracerebrally with a pooled suspension of brain from cattle that had died of encephalopathy after experimental inoculation with brain from scrapie-affected sheep. The second passage disease was essentially identical with the first passage disease, as judged by clinical signs, histopathological findings and distribution of "prion protein scrapie" (PrPsc). This represents additional evidence to suggest that the US sheep scrapie agent tested is incapable of causing BSE in cattle.
IT seems that Cutlip, Miller, Lehmkuhl et al, it seems by this statement ;
'suggest that the US sheep scrapie agent tested is incapable of causing BSE in cattle.'
THAT the USA is home free from TSEs, however, how many scrapie strains are in the USA, including the atypical. we know atypical scrapie Nor-98 has been in the USA for a while, only detected recently. but did this study include all USA scrapie strains typical and atypical ??? I dont think so. also, this TSE strain that is produced by USA scrapie, could it be more virulent, and how many phenotypes are there ??? we know that the atypical BSE is more virulent, so I dont understand what seems to be 'jubilation' of the small study that shows that in fact the USA scrapie DOES produce a Transmissible Spongiform Encephalopathy TSE, it just happens to be unlike that of the UK BSE phenotype, and I would have expected nothing less, considering the many different strains. but I don't think these findings makes the USA mad cow free. IN fact, I find that by these findings, TSE in the USA bovine could have gone way back before the UK BSE epidemic, and I think it's just possible that the USA started this epidemic of TSEs.
let's look at the new atypical scrapie that has been in the U.S.A. i.e. the NOR-98-like;-) strain ;
PLEASE NOTE, (FIGURE 6), Scrapie Confirmed Cases in FY 2008 MAP, PA 3, 1**, Two cases-state of ID UNKNOWN, 1 case Nor98-like**
WEDNESDAY, JUNE 10, 2020
Radical Change in Zoonotic Abilities of Atypical BSE Prion Strains as Evidenced by Crossing of Sheep Species Barrier in Transgenic Mice
Atypical BSE prions showed a modification in their zoonotic ability after adaptation to sheep-PrP producing agents able to infect TgMet129 and TgVal129, bearing features that make them indistinguishable of sporadic Creutzfeldt-Jakob disease prions.
our results clearly indicate that atypical BSE adaptation to an ovine-PrP sequence could modify the prion agent to potentially infect humans, showing strain features indistinguishable from those of classic sCJD prions, even though they might or might not be different agents.
However, the expanding range of TSE agents displaying the capacity to transmit in human-PrP–expressing hosts warrants the continuation of the ban on meat and bone meal recycling and underscores the ongoing need for active surveillance
WEDNESDAY, JULY 31, 2019
The agent of transmissible mink encephalopathy passaged in sheep is similar to BSE-L
THURSDAY, SEPTEMBER 24, 2020
***> The emergence of classical BSE from atypical/ Nor98 scrapie <***
MONDAY, JULY 27, 2020
APHIS USDA Nor98-like scrapie was confirmed in a sheep sampled at slaughter in May 2020
A REVIEW of facts and science on scrapie zoonosis potential/likelihood and the USA incredible failure of the BSE 589.2001 FEED REGULATIONS (another colossal failure, and proven to be a sham)
***> 1st up BSE 589.2001 FEED REGULATIONS
SUNDAY, OCTOBER 4, 2020
Cattle Meat and Offal Imported from the United States of America, Canada and Ireland to Japan (Prions) Food Safety Commission of Japan
''Why is USDA "only" testing 25,000 samples a year?
TUESDAY, AUGUST 18, 2020
Sheep Scrapie, Bovine BSE, Cervid CWD, ZOONOSIS, TSE Prion Roundup August 18, 2020
TUESDAY, SEPTEMBER 22, 2020
APHIS USDA MORE SCRAPIE ATYPICAL Nor-98 Confirmed USA September 15 2020
MAD COW DISEASE ALABAMA 2017
***> WEDNESDAY, JULY 19, 2017
***> USDA OIE Alabama Atypical L-type BASE Bovine Spongiform Encephalopathy BSE and BANNED FEED USDA Detects a Case of Atypical Bovine Spongiform Encephalopathy in Alabama
USDA Animal and Plant Health Inspection Service sent this bulletin at 07/18/2017 07:05 PM EDT
USDA Detects a Case of Atypical Bovine Spongiform Encephalopathy in Alabama
Washington, D.C., July 18, 2017 – The U.S. Department of Agriculture (USDA) announced an atypical case of Bovine Spongiform Encephalopathy (BSE), a neurologic disease of cattle, in an eleven-year old cow in Alabama. This animal never entered slaughter channels and at no time presented a risk to the food supply, or to human health in the United States.
snip...end
2009 UPDATE ON ALABAMA AND TEXAS MAD COWS 2005 and 2006
Oral Transmission of L-Type Bovine Spongiform Encephalopathy Agent among Cattle
CDC Volume 23, Number 2—February 2017
*** Consumption of L-BSE–contaminated feed may pose a risk for oral transmission of the disease agent to cattle.
Prion 2018 Conference
P98 The agent of H-type bovine spongiform encephalopathy associated with E211K prion protein polymorphism transmits after oronasal challenge
This study demonstrates that the H-type BSE agent is transmissible by the oronasal route. These results reinforce the need for ongoing surveillance for classical and atypical BSE to minimize the risk of potentially infectious tissues entering the animal or human food chains.
Prion 2018 Conference
P04.27
Experimental BSE Infection of Non-human Primates: Efficacy of the Oral Route
Holznagel, E1; Yutzy, B1; Deslys, J-P2; Lasmézas, C2; Pocchiari, M3; Ingrosso, L3; Bierke, P4; Schulz-Schaeffer, W5; Motzkus, D6; Hunsmann, G6; Löwer, J1 1Paul-Ehrlich-Institut, Germany; 2Commissariat à l´Energie Atomique, France; 3Instituto Superiore di Sanità, Italy; 4Swedish Institute for Infectious Disease control, Sweden; 5Georg August University, Germany; 6German Primate Center, Germany
Background:
In 2001, a study was initiated in primates to assess the risk for humans to contract BSE through contaminated food. For this purpose, BSE brain was titrated in cynomolgus monkeys.
Aims:
The primary objective is the determination of the minimal infectious dose (MID50) for oral exposure to BSE in a simian model, and, by in doing this, to assess the risk for humans. Secondly, we aimed at examining the course of the disease to identify possible biomarkers.
Methods:
Groups with six monkeys each were orally dosed with lowering amounts of BSE brain: 16g, 5g, 0.5g, 0.05g, and 0.005g. In a second titration study, animals were intracerebrally (i.c.) dosed (50, 5, 0.5, 0.05, and 0.005 mg).
Results:
In an ongoing study, a considerable number of high-dosed macaques already developed simian vCJD upon oral or intracerebral exposure or are at the onset of the clinical phase. However, there are differences in the clinical course between orally and intracerebrally infected animals that may influence the detection of biomarkers.
Conclusions:
Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate. The difference in the incubation period between 5 g oral and 5 mg i.c. is only 1 year (5 years versus 4 years). However, there are rapid progressors among orally dosed monkeys that develop simian v CJD as fast as intracerebrally inoculated animals.
The work referenced was performed in partial fulfillment of the study “BSE in primates“ supported by the EU (QLK1-2002-01096).
Simian vCJD can be easily triggered in cynomolgus monkeys on the oral route using less than 5 g BSE brain homogenate.
look at the table and you'll see that as little as 1 mg (or 0.001 gm) caused 7% (1 of 14) of the cows to come down with BSE;
Risk of oral infection with bovine spongiform encephalopathy agent in primates
Corinne Ida Lasmézas, Emmanuel Comoy, Stephen Hawkins, Christian Herzog, Franck Mouthon, Timm Konold, Frédéric Auvré, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Nicole Salès, Gerald Wells, Paul Brown, Jean-Philippe Deslys Summary The uncertain extent of human exposure to bovine spongiform encephalopathy (BSE)--which can lead to variant Creutzfeldt-Jakob disease (vCJD)--is compounded by incomplete knowledge about the efficiency of oral infection and the magnitude of any bovine-to-human biological barrier to transmission. We therefore investigated oral transmission of BSE to non-human primates. We gave two macaques a 5 g oral dose of brain homogenate from a BSE-infected cow. One macaque developed vCJD-like neurological disease 60 months after exposure, whereas the other remained free of disease at 76 months. On the basis of these findings and data from other studies, we made a preliminary estimate of the food exposure risk for man, which provides additional assurance that existing public health measures can prevent transmission of BSE to man.
snip...
BSE bovine brain inoculum
100 g 10 g 5 g 1 g 100 mg 10 mg 1 mg 0·1 mg 0·01 mg
Primate (oral route)* 1/2 (50%)
Cattle (oral route)* 10/10 (100%) 7/9 (78%) 7/10 (70%) 3/15 (20%) 1/15 (7%) 1/15 (7%)
RIII mice (ic ip route)* 17/18 (94%) 15/17 (88%) 1/14 (7%)
PrPres biochemical detection
The comparison is made on the basis of calibration of the bovine inoculum used in our study with primates against a bovine brain inoculum with a similar PrPres concentration that was
inoculated into mice and cattle.8 *Data are number of animals positive/number of animals surviving at the time of clinical onset of disease in the first positive animal (%). The accuracy of
bioassays is generally judged to be about plus or minus 1 log. ic ip=intracerebral and intraperitoneal.
Table 1: Comparison of transmission rates in primates and cattle infected orally with similar BSE brain inocula
Published online January 27, 2005
Calves were challenged by mouth with homogenised brain from confirmed cases of BSE. Some received 300g (3 doses of 100g), some 100g, 10g or 1g. They were then left to develop BSE, but were not subjected to the normal stresses that they might have encountered in a dairy herd. Animals in all four groups developed BSE. There has been a considerable spread of incubation period in some of the groups, but it appears as if those in the 1 and 10g challenge groups most closely fit the picture of incubation periods seen in the epidemic. Experiments in progress indicate that oral infection can occur in some animals with doses as low as 0.01g and 0.001g. .........
It is clear that the designing scientists must also have shared Mr Bradley's surprise at the results because all the dose levels right down to 1 gram triggered infection.
6. It also appears to me that Mr Bradley's answer (that it would take less than say 100 grams) was probably given with the benefit of hindsight; particularly if one considers that later in the same answer Mr Bradley expresses his surprise that it could take as little of 1 gram of brain to cause BSE by the oral route within the same species. This information did not become available until the "attack rate" experiment had been completed in 1995/96. This was a titration experiment designed to ascertain the infective dose. A range of dosages was used to ensure that the actual result was within both a lower and an upper limit within the study and the designing scientists would not have expected all the dose levels to trigger infection. The dose ranges chosen by the most informed scientists at that time ranged from 1 gram to three times one hundred grams. It is clear that the designing scientists must have also shared Mr Bradley's surprise at the results because all the dose levels right down to 1 gram triggered infection.
Saturday, June 25, 2011
Transmissibility of BSE-L and Cattle-Adapted TME Prion Strain to Cynomolgus Macaque
"BSE-L in North America may have existed for decades"
THURSDAY, AUGUST 20, 2020
Why is USDA "only" BSE TSE Prion testing 25,000 samples a year?
USDA/FDA MAD COW PROTEIN IN COMMERCE 2006
MAD COW FEED RECALL USA SEPT 6, 2006 1961.72 TONS IN COMMERCE AL, TN, AND WV
Date: September 6, 2006 at 7:58 am PST
PRODUCT
a) EVSRC Custom dairy feed, Recall # V-130-6;
b) Performance Chick Starter, Recall # V-131-6;
c) Performance Quail Grower, Recall # V-132-6;
d) Performance Pheasant Finisher, Recall # V-133-6.
CODE
None
RECALLING FIRM/MANUFACTURER
Donaldson & Hasenbein/dba J&R Feed Service, Inc., Cullman, AL, by telephone on June 23, 2006 and by letter dated July 19, 2006. Firm initiated recall is complete.
REASON
Dairy and poultry feeds were possibly contaminated with ruminant based protein.
VOLUME OF PRODUCT IN COMMERCE
477.72 tons
DISTRIBUTION
AL
______________________________
PRODUCT
a) Dairy feed, custom, Recall # V-134-6;
b) Custom Dairy Feed with Monensin, Recall # V-135-6.
CODE
None. Bulk product
RECALLING FIRM/MANUFACTURER
Recalling Firm: Burkmann Feed, Greeneville, TN, by Telephone beginning on June 28, 2006.
Manufacturer: H. J. Baker & Bro., Inc., Albertville, AL. Firm initiated recall is complete.
REASON Possible contamination of dairy feeds with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 1,484 tons
DISTRIBUTION TN and WV
http://www.fda.gov/bbs/topics/enforce/2006/ENF00968.html
Subject: MAD COW FEED RECALLS ENFORCEMENT REPORT FOR AUGUST 9, 2006 KY, LA, MS, AL, GA, AND TN 11,000+ TONS
Date: August 16, 2006 at 9:19 am PST
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINE - CLASS II ______________________________
PRODUCT
Bulk custom made dairy feed, Recall # V-115-6
CODE
None
RECALLING FIRM/MANUFACTURER
Hiseville Feed & Seed Co., Hiseville, KY, by telephone and letter on or about July 14, 2006. FDA initiated recall is ongoing.
REASON
Custom made feeds contain ingredient called Pro-Lak which may contain ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE
Approximately 2,223 tons
DISTRIBUTION
KY ______________________________
PRODUCT
Bulk custom made dairy feed, Recall # V-116-6
CODE
None
RECALLING FIRM/MANUFACTURER
Rips Farm Center, Tollesboro, KY, by telephone and letter on July 14, 2006.
FDA initiated recall is ongoing.
REASON
Custom made feeds contain ingredient called Pro-Lak which may contain ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 1,220 tons
DISTRIBUTION KY
______________________________
PRODUCT Bulk custom made dairy feed, Recall # V-117-6
CODE
None
RECALLING FIRM/MANUFACTURER
Kentwood Co-op, Kentwood, LA, by telephone on June 27, 2006. FDA initiated recall is completed.
REASON
Possible contamination of animal feed ingredients, including ingredients that are used in feed for dairy animals, with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 40 tons
DISTRIBUTION LA and MS ______________________________
PRODUCT
Bulk Dairy Feed, Recall V-118-6
CODE
None
RECALLING FIRM/MANUFACTURER
Cal Maine Foods, Inc., Edwards, MS, by telephone on June 26, 2006. FDA initiated recall is complete.
REASON
Possible contamination of animal feed ingredients, including ingredients that are used in feed for dairy animals, with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 7,150 tons
DISTRIBUTION
MS
______________________________
PRODUCT
Bulk custom dairy pre-mixes, Recall # V-119-6
CODE
None
RECALLING FIRM/MANUFACTURER
Walthall County Co-op, Tylertown, MS, by telephone on June 26, 2006. Firm initiated recall is complete.
REASON
Possible contamination of dairy animal feeds with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 87 tons
DISTRIBUTION MS ______________________________
PRODUCT
Bulk custom dairy pre-mixes, Recall # V-120-6
CODE
None
RECALLING FIRM/MANUFACTURER
Ware Milling Inc., Houston, MS, by telephone on June 23, 2006. Firm initiated recall is complete.
REASON
Possible contamination of dairy animal feeds with ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE 350 tons
DISTRIBUTION AL and MS
______________________________
PRODUCT
a) Tucker Milling, LLC Tm 32% Sinking Fish Grower, #2680-Pellet,
50 lb. bags, Recall # V-121-6;
b) Tucker Milling, LLC #31120, Game Bird Breeder Pellet,
50 lb. bags, Recall # V-122-6;
c) Tucker Milling, LLC #31232 Game Bird Grower,
50 lb. bags, Recall # V-123-6;
d) Tucker Milling, LLC 31227-Crumble, Game Bird Starter, BMD Medicated, 50 lb bags, Recall # V-124-6;
e) Tucker Milling, LLC #31120, Game Bird Breeder, 50 lb bags, Recall # V-125-6;
f) Tucker Milling, LLC #30230, 30 % Turkey Starter, 50 lb bags, Recall # V-126-6;
g) Tucker Milling, LLC #30116, TM Broiler Finisher, 50 lb bags, Recall # V-127-6
CODE
All products manufactured from 02/01/2005 until 06/20/2006
RECALLING FIRM/MANUFACTURER
Recalling Firm: Tucker Milling LLC, Guntersville, AL, by telephone and visit on June 20, 2006, and by letter on June 23, 2006.
Manufacturer: H. J. Baker and Brothers Inc., Stamford, CT. Firm initiated recall is ongoing.
REASON Poultry and fish feeds which were possibly contaminated with ruminant based protein were not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE
7,541-50 lb bags
DISTRIBUTION
AL, GA, MS, and TN
END OF ENFORCEMENT REPORT FOR AUGUST 9, 2006
###
http://www.fda.gov/bbs/topics/ENFORCE/2006/ENF00964.html
Subject: MAD COW FEED RECALL MI MAMMALIAN PROTEIN VOLUME OF PRODUCT IN COMMERCE 27,694,240 lbs
Date: August 6, 2006 at 6:14 pm PST
PRODUCT
Bulk custom dairy feds manufactured from concentrates, Recall # V-113-6
CODE
All dairy feeds produced between 2/1/05 and 6/16/06 and containing H. J. Baker recalled feed products.
RECALLING FIRM/MANUFACTURER
Vita Plus Corp., Gagetown, MI, by visit beginning on June 21, 2006. Firm initiated recall is complete.
REASON
The feed was manufactured from materials that may have been contaminated with mammalian protein.
VOLUME OF PRODUCT IN COMMERCE 27,694,240 lbs
DISTRIBUTION
MI
END OF ENFORCEMENT REPORT FOR AUGUST 2, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00963.html
Subject: MAD COW FEED RECALL AL AND FL VOLUME OF PRODUCT IN COMMERCE 125 TONS Products manufactured from 02/01/2005 until 06/06/2006
Date: August 6, 2006 at 6:16 pm PST
PRODUCT
a) CO-OP 32% Sinking Catfish, Recall # V-100-6;
b) Performance Sheep Pell W/Decox/A/N, medicated, net wt. 50 lbs, Recall # V-101-6;
c) Pro 40% Swine Conc Meal -- 50 lb, Recall # V-102-6;
d) CO-OP 32% Sinking Catfish Food Medicated, Recall # V-103-6;
e) "Big Jim's" BBB Deer Ration, Big Buck Blend, Recall # V-104-6;
f) CO-OP 40% Hog Supplement Medicated Pelleted, Tylosin 100 grams/ton, 50 lb. bag, Recall # V-105-6;
g) Pig Starter Pell II, 18% W/MCDX Medicated 282020, Carbadox -- 0.0055%, Recall # V-106-6;
h) CO-OP STARTER-GROWER CRUMBLES, Complete Feed for Chickens from Hatch to 20 Weeks, Medicated, Bacitracin Methylene Disalicylate, 25 and 50 Lbs, Recall # V-107-6;
i) CO-OP LAYING PELLETS, Complete Feed for Laying Chickens, Recall # 108-6;
j) CO-OP LAYING CRUMBLES, Recall # V-109-6;
k) CO-OP QUAIL FLIGHT CONDITIONER MEDICATED, net wt 50 Lbs, Recall # V-110-6;
l) CO-OP QUAIL STARTER MEDICATED, Net Wt. 50 Lbs, Recall # V-111-6;
m) CO-OP QUAIL GROWER MEDICATED, 50 Lbs, Recall # V-112-6
CODE
Product manufactured from 02/01/2005 until 06/06/2006
RECALLING FIRM/MANUFACTURER
Alabama Farmers Cooperative, Inc., Decatur, AL, by telephone, fax, email and visit on June 9, 2006. FDA initiated recall is complete.
REASON
Animal and fish feeds which were possibly contaminated with ruminant based protein not labeled as "Do not feed to ruminants".
VOLUME OF PRODUCT IN COMMERCE
125 tons
DISTRIBUTION
AL and FL
END OF ENFORCEMENT REPORT FOR AUGUST 2, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00963.html
Subject: MAD COW FEED RECALL KY VOLUME OF PRODUCT IN COMMERCE ?????
Date: August 6, 2006 at 6:19 pm PST
PRODUCT
Bulk custom made dairy feed, Recall # V-114-6
CODE
None
RECALLING FIRM/MANUFACTURER
Burkmann Feeds LLC, Glasgow, KY, by letter on July 14, 2006. Firm initiated recall is ongoing.
REASON
Custom made feeds contain ingredient called Pro-Lak, which may contain ruminant derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE ?????
DISTRIBUTION KY
END OF ENFORCEMENT REPORT FOR AUGUST 2, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00963.html
CJD WATCH MESSAGE BOARD
TSS
MAD COW FEED RECALL USA EQUALS 10,878.06 TONS NATIONWIDE Sun Jul 16, 2006 09:22
71.248.128.67
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINE -- CLASS II ______________________________
PRODUCT
a) PRO-LAK, bulk weight, Protein Concentrate for Lactating Dairy Animals, Recall # V-079-6;
b) ProAmino II, FOR PREFRESH AND LACTATING COWS, net weight 50lb (22.6 kg), Recall # V-080-6;
c) PRO-PAK, MARINE & ANIMAL PROTEIN CONCENTRATE FOR USE IN ANIMAL FEED, Recall # V-081-6;
d) Feather Meal, Recall # V-082-6
CODE
a) Bulk
b) None
c) Bulk
d) Bulk
RECALLING FIRM/MANUFACTURER
H. J. Baker & Bro., Inc., Albertville, AL, by telephone on June 15, 2006 and by press release on June 16, 2006. Firm initiated recall is ongoing.
REASON
Possible contamination of animal feeds with ruminent derived meat and bone meal.
VOLUME OF PRODUCT IN COMMERCE
10,878.06 tons
DISTRIBUTION
Nationwide
END OF ENFORCEMENT REPORT FOR July 12, 2006
###
http://www.fda.gov/bbs/topics/enforce/2006/ENF00960.html
10 years post mad cow feed ban August 1997
10,000,000+ LBS. of PROHIBITED BANNED MAD COW FEED I.E. BLOOD LACED MBM IN COMMERCE USA 2007
Date: March 21, 2007 at 2:27 pm PST
RECALLS AND FIELD CORRECTIONS: VETERINARY MEDICINES -- CLASS II PRODUCT
Bulk cattle feed made with recalled Darling's 85% Blood Meal, Flash Dried, Recall # V-024-2007 CODE Cattle feed delivered between 01/12/2007 and 01/26/2007 RECALLING FIRM/MANUFACTURER Pfeiffer, Arno, Inc, Greenbush, WI. by conversation on February 5, 2007.
Firm initiated recall is ongoing.
REASON Blood meal used to make cattle feed was recalled because it was cross- contaminated with prohibited bovine meat and bone meal that had been manufactured on common equipment and labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE 42,090 lbs. DISTRIBUTION WI
___________________________________
PRODUCT Custom dairy premix products: MNM ALL PURPOSE Pellet, HILLSIDE/CDL Prot- Buffer Meal, LEE, M.-CLOSE UP PX Pellet, HIGH DESERT/ GHC LACT Meal, TATARKA, M CUST PROT Meal, SUNRIDGE/CDL PROTEIN Blend, LOURENZO, K PVM DAIRY Meal, DOUBLE B DAIRY/GHC LAC Mineral, WEST PIONT/GHC CLOSEUP Mineral, WEST POINT/GHC LACT Meal, JENKS, J/COMPASS PROTEIN Meal, COPPINI - 8# SPECIAL DAIRY Mix, GULICK, L-LACT Meal (Bulk), TRIPLE J - PROTEIN/LACTATION, ROCK CREEK/GHC MILK Mineral, BETTENCOURT/GHC S.SIDE MK-MN, BETTENCOURT #1/GHC MILK MINR, V&C DAIRY/GHC LACT Meal, VEENSTRA, F/GHC LACT Meal, SMUTNY, A- BYPASS ML W/SMARTA,
Recall # V-025-2007
CODE The firm does not utilize a code - only shipping documentation with commodity and weights identified.
RECALLING FIRM/MANUFACTURER Rangen, Inc, Buhl, ID, by letters on February 13 and 14, 2007.
Firm initiated recall is complete.
REASON Products manufactured from bulk feed containing blood meal that was cross contaminated with prohibited meat and bone meal and the labeling did not bear cautionary BSE statement.
VOLUME OF PRODUCT IN COMMERCE 9,997,976 lbs. DISTRIBUTION ID and NV END OF ENFORCEMENT REPORT FOR MARCH 21, 2007
PRODUCT O-NO-MORE (Formerly ORPHAN-NO-MORE) Calf Claimer Powder, packaged in 11-oz. bottles, For Animal Use Only.
Recall # V-043-2007 CODE A06 RECALLING FIRM/MANUFACTURER Springer Magrath Co., Mc Cook, NE, by telephone on January 2, 2007, fax dated January 9, 2007, by letters on February 22, 2007, March 12, March 14 and March 21, 2007.
Firm initiated recall is ongoing.
REASON The finished product was manufactured with prohibited bovine blood meal and did not bear the cautionary BSE statement that the product should not be fed to ruminants.
VOLUME OF PRODUCT IN COMMERCE
Approximately 13,255 bottles DISTRIBUTION
Nationwide
END OF ENFORCEMENT REPORT FOR JUNE 13, 2007 ###
SUNDAY, OCTOBER 4, 2020
Cattle Meat and Offal Imported from the United States of America, Canada and Ireland to Japan (Prions) Food Safety Commission of Japan
ZOONOSIS OF SCRAPIE TSE PRION
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, Valerie 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 long 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***
===============
***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.
==============
***Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
***Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
***These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
PRION 2016 TOKYO
Saturday, April 23, 2016
SCRAPIE WS-01: Prion diseases in animals and zoonotic potential 2016
Prion. 10:S15-S21. 2016 ISSN: 1933-6896 printl 1933-690X online
Taylor & Francis
Prion 2016 Animal Prion Disease Workshop Abstracts
WS-01: Prion diseases in animals and zoonotic potential
Juan Maria Torres a, Olivier Andreoletti b, J uan-Carlos Espinosa a. Vincent Beringue c. Patricia Aguilar a,
Natalia Fernandez-Borges a. and Alba Marin-Moreno a
"Centro de Investigacion en Sanidad Animal ( CISA-INIA ). Valdeolmos, Madrid. Spain; b UMR INRA -ENVT 1225 Interactions Holes Agents Pathogenes. ENVT. Toulouse. France: "UR892. Virologie lmmunologie MolécuIaires, Jouy-en-Josas. France
Dietary exposure to bovine spongiform encephalopathy (BSE) contaminated bovine tissues is considered as the origin of variant Creutzfeldt Jakob (vCJD) disease in human. To date, BSE agent is the only recognized zoonotic prion... Despite the variety of Transmissible Spongiform Encephalopathy (TSE) agents that have been circulating for centuries in farmed ruminants there is no apparent epidemiological link between exposure to ruminant products and the occurrence of other form of TSE in human like sporadic Creutzfeldt Jakob Disease (sCJD). However, the zoonotic potential of the diversity of circulating TSE agents has never been systematically assessed. The major issue in experimental assessment of TSEs zoonotic potential lies in the modeling of the ‘species barrier‘, the biological phenomenon that limits TSE agents’ propagation from a species to another. In the last decade, mice genetically engineered to express normal forms of the human prion protein has proved essential in studying human prions pathogenesis and modeling the capacity of TSEs to cross the human species barrier.
To assess the zoonotic potential of prions circulating in farmed ruminants, we study their transmission ability in transgenic mice expressing human PrPC (HuPrP-Tg). Two lines of mice expressing different forms of the human PrPC (129Met or 129Val) are used to determine the role of the Met129Val dimorphism in susceptibility/resistance to the different agents.
These transmission experiments confirm the ability of BSE prions to propagate in 129M- HuPrP-Tg mice and demonstrate that Met129 homozygotes may be susceptible to BSE in sheep or goat to a greater degree than the BSE agent in cattle and that these agents can convey molecular properties and neuropathological indistinguishable from vCJD. However homozygous 129V mice are resistant to all tested BSE derived prions independently of the originating species suggesting a higher transmission barrier for 129V-PrP variant.
Transmission data also revealed that several scrapie prions propagate in HuPrP-Tg mice with efficiency comparable to that of cattle BSE. While the efficiency of transmission at primary passage was low, subsequent passages resulted in a highly virulent prion disease in both Met129 and Val129 mice.
Transmission of the different scrapie isolates in these mice leads to the emergence of prion strain phenotypes that showed similar characteristics to those displayed by MM1 or VV2 sCJD prion.
These results demonstrate that scrapie prions have a zoonotic potential and raise new questions about the possible link between animal and human prions.
***> why do we not want to do TSE transmission studies on chimpanzees $
5. A positive result from a chimpanzee challenged severly would likely create alarm in some circles even if the result could not be interpreted for man.
***> I have a view that all these agents could be transmitted provided a large enough dose by appropriate routes was given and the animals kept long enough.
***> Until the mechanisms of the species barrier are more clearly understood it might be best to retain that hypothesis.
snip...
R. BRADLEY
Title: Transmission of scrapie prions to primate after an extended silent incubation period)
*** In complement to the recent demonstration that humanized mice are susceptible to scrapie, we report here the first observation of direct transmission of a natural classical scrapie isolate to a macaque after a 10-year incubation period. Neuropathologic examination revealed all of the features of a prion disease: spongiform change, neuronal loss, and accumulation of PrPres throughout the CNS.
*** This observation strengthens the questioning of the harmlessness of scrapie to humans, at a time when protective measures for human and animal health are being dismantled and reduced as c-BSE is considered controlled and being eradicated.
*** Our results underscore the importance of precautionary and protective measures and the necessity for long-term experimental transmission studies to assess the zoonotic potential of other animal prion strains.
***> Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility. <***
Transmission of scrapie prions to primate after an extended silent incubation period
Emmanuel E. Comoy, Jacqueline Mikol, Sophie Luccantoni-Freire, Evelyne Correia, Nathalie Lescoutra-Etchegaray, Valérie Durand, Capucine Dehen, Olivier Andreoletti, Cristina Casalone, Juergen A. Richt, Justin J. Greenlee, Thierry Baron, Sylvie L. Benestad, Paul Brown & Jean-Philippe Deslys Scientific Reports volume 5, Article number: 11573 (2015) | Download Citation
Abstract
Classical bovine spongiform encephalopathy (c-BSE) is the only animal prion disease reputed to be zoonotic, causing variant Creutzfeldt-Jakob disease (vCJD) in humans and having guided protective measures for animal and human health against animal prion diseases. Recently, partial transmissions to humanized mice showed that the zoonotic potential of scrapie might be similar to c-BSE. We here report the direct transmission of a natural classical scrapie isolate to cynomolgus macaque, a highly relevant model for human prion diseases, after a 10-year silent incubation period, with features similar to those reported for human cases of sporadic CJD. Scrapie is thus actually transmissible to primates with incubation periods compatible with their life expectancy, although fourfold longer than BSE. Long-term experimental transmission studies are necessary to better assess the zoonotic potential of other prion diseases with high prevalence, notably Chronic Wasting Disease of deer and elk and atypical/Nor98 scrapie.
SNIP...
Discussion We describe the transmission of spongiform encephalopathy in a non-human primate inoculated 10 years earlier with a strain of sheep c-scrapie. Because of this extended incubation period in a facility in which other prion diseases are under study, we are obliged to consider two alternative possibilities that might explain its occurrence. We first considered the possibility of a sporadic origin (like CJD in humans). Such an event is extremely improbable because the inoculated animal was 14 years old when the clinical signs appeared, i.e. about 40% through the expected natural lifetime of this species, compared to a peak age incidence of 60–65 years in human sporadic CJD, or about 80% through their expected lifetimes. Moreover, sporadic disease has never been observed in breeding colonies or primate research laboratories, most notably among hundreds of animals over several decades of study at the National Institutes of Health25, and in nearly twenty older animals continuously housed in our own facility.
The second possibility is a laboratory cross-contamination. Three facts make this possibility equally unlikely. First, handling of specimens in our laboratory is performed with fastidious attention to the avoidance of any such cross-contamination. Second, no laboratory cross-contamination has ever been documented in other primate laboratories, including the NIH, even between infected and uninfected animals housed in the same or adjacent cages with daily intimate contact (P. Brown, personal communication). Third, the cerebral lesion profile is different from all the other prion diseases we have studied in this model19, with a correlation between cerebellar lesions (massive spongiform change of Purkinje cells, intense PrPres staining and reactive gliosis26) and ataxia. The iron deposits present in the globus pallidus are a non specific finding that have been reported previously in neurodegenerative diseases and aging27. Conversely, the thalamic lesion was reminiscent of a metabolic disease due to thiamine deficiency28 but blood thiamine levels were within normal limits (data not shown). The preferential distribution of spongiform change in cortex associated with a limited distribution in the brainstem is reminiscent of the lesion profile in MM2c and VV1 sCJD patients29, but interspecies comparison of lesion profiles should be interpreted with caution. It is of note that the same classical scrapie isolate induced TSE in C57Bl/6 mice with similar incubation periods and lesional profiles as a sample derived from a MM1 sCJD patient30.
We are therefore confident that the illness in this cynomolgus macaque represents a true transmission of a sheep c-scrapie isolate directly to an old-world monkey, which taxonomically resides in the primate subdivision (parvorder of catarrhini) that includes humans. With an homology of its PrP protein with humans of 96.4%31, cynomolgus macaque constitutes a highly relevant model for assessing zoonotic risk of prion diseases. Since our initial aim was to show the absence of transmission of scrapie to macaques in the worst-case scenario, we obtained materials from a flock of naturally-infected sheep, affecting animals with different genotypes32. This c-scrapie isolate exhibited complete transmission in ARQ/ARQ sheep (332 ± 56 days) and Tg338 transgenic mice expressing ovine VRQ/VRQ prion protein (220 ± 5 days) (O. Andreoletti, personal communication). From the standpoint of zoonotic risk, it is important to note that sheep with c-scrapie (including the isolate used in our study) have demonstrable infectivity throughout their lymphoreticular system early in the incubation period of the disease (3 months-old for all the lymphoid organs, and as early as 2 months-old in gut-associated lymph nodes)33. In addition, scrapie infectivity has been identified in blood34, milk35 and skeletal muscle36 from asymptomatic but scrapie infected small ruminants which implies a potential dietary exposure for consumers.
Two earlier studies have reported the occurrence of clinical TSE in cynomolgus macaques after exposures to scrapie isolates. In the first study, the “Compton” scrapie isolate (derived from an English sheep) and serially propagated for 9 passages in goats did not transmit TSE in cynomolgus macaque, rhesus macaque or chimpanzee within 7 years following intracerebral challenge1; conversely, after 8 supplementary passages in conventional mice, this “Compton” isolate induced TSE in a cynomolgus macaque 5 years after intracerebral challenge, but rhesus macaques and chimpanzee remained asymptomatic 8.5 years post-exposure8. However, multiple successive passages that are classically used to select laboratory-adapted prion strains can significantly modify the initial properties of a scrapie isolate, thus questioning the relevance of zoonotic potential for the initial sheep-derived isolate. The same isolate had also induced disease into squirrel monkeys (new-world monkey)9. A second historical observation reported that a cynomolgus macaque developed TSE 6 years post-inoculation with brain homogenate from a scrapie-infected Suffolk ewe (derived from USA), whereas a rhesus macaque and a chimpanzee exposed to the same inoculum remained healthy 9 years post-exposure1. This inoculum also induced TSE in squirrel monkeys after 4 passages in mice. Other scrapie transmission attempts in macaque failed but had more shorter periods of observation in comparison to the current study. Further, it is possible that there are differences in the zoonotic potential of different scrapie strains.
The most striking observation in our study is the extended incubation period of scrapie in the macaque model, which has several implications. Firstly, our observations constitute experimental evidence in favor of the zoonotic potential of c-scrapie, at least for this isolate that has been extensively studied32,33,34,35,36. The cross-species zoonotic ability of this isolate should be confirmed by performing duplicate intracerebral exposures and assessing the transmissibility by the oral route (a successful transmission of prion strains through the intracerebral route may not necessarily indicate the potential for oral transmission37). However, such confirmatory experiments may require more than one decade, which is hardly compatible with current general management and support of scientific projects; thus this study should be rather considered as a case report.
Secondly, transmission of c-BSE to primates occurred within 8 years post exposure for the lowest doses able to transmit the disease (the survival period after inoculation is inversely proportional to the initial amount of infectious inoculum). The occurrence of scrapie 10 years after exposure to a high dose (25 mg) of scrapie-infected sheep brain suggests that the macaque has a higher species barrier for sheep c-scrapie than c-BSE, although it is notable that previous studies based on in vitro conversion of PrP suggested that BSE and scrapie prions would have a similar conversion potential for human PrP38.
Thirdly, prion diseases typically have longer incubation periods after oral exposure than after intracerebral inoculations: since humans can develop Kuru 47 years after oral exposure39, an incubation time of several decades after oral exposure to scrapie would therefore be expected, leading the disease to occur in older adults, i.e. the peak age for cases considered to be sporadic disease, and making a distinction between scrapie-associated and truly sporadic disease extremely difficult to appreciate.
Fourthly, epidemiologic evidence is necessary to confirm the zoonotic potential of an animal disease suggested by experimental studies. A relatively short incubation period and a peculiar epidemiological situation (e.g., all the first vCJD cases occurring in the country with the most important ongoing c-BSE epizootic) led to a high degree of suspicion that c-BSE was the cause of vCJD. Sporadic CJD are considered spontaneous diseases with an almost stable and constant worldwide prevalence (0.5–2 cases per million inhabitants per year), and previous epidemiological studies were unable to draw a link between sCJD and classical scrapie6,7,40,41, even though external causes were hypothesized to explain the occurrence of some sCJD clusters42,43,44. However, extended incubation periods exceeding several decades would impair the predictive values of epidemiological surveillance for prion diseases, already weakened by a limited prevalence of prion diseases and the multiplicity of isolates gathered under the phenotypes of “scrapie” and “sporadic CJD”.
Fifthly, considering this 10 year-long incubation period, together with both laboratory and epidemiological evidence of decade or longer intervals between infection and clinical onset of disease, no premature conclusions should be drawn from negative transmission studies in cynomolgus macaques with less than a decade of observation, as in the aforementioned historical transmission studies of scrapie to primates1,8,9. Our observations and those of others45,46 to date are unable to provide definitive evidence regarding the zoonotic potential of CWD, atypical/Nor98 scrapie or H-type BSE. The extended incubation period of the scrapie-affected macaque in the current study also underscores the limitations of rodent models expressing human PrP for assessing the zoonotic potential of some prion diseases since their lifespan remains limited to approximately two years21,47,48. This point is illustrated by the fact that the recently reported transmission of scrapie to humanized mice was not associated with clinical signs for up to 750 days and occurred in an extreme minority of mice with only a marginal increase in attack rate upon second passage13. The low attack rate in these studies is certainly linked to the limited lifespan of mice compared to the very long periods of observation necessary to demonstrate the development of scrapie. Alternatively, one could estimate that a successful second passage is the result of strain adaptation to the species barrier, thus poorly relevant of the real zoonotic potential of the original scrapie isolate of sheep origin49. The development of scrapie in this primate after an incubation period compatible with its lifespan complements the study conducted in transgenic (humanized) mice; taken together these studies suggest that some isolates of sheep scrapie can promote misfolding of the human prion protein and that scrapie can develop within the lifespan of some primate species.
In addition to previous studies on scrapie transmission to primate1,8,9 and the recently published study on transgenic humanized mice13, our results constitute new evidence for recommending that the potential risk of scrapie for human health should not be dismissed. Indeed, human PrP transgenic mice and primates are the most relevant models for investigating the human transmission barrier. To what extent such models are informative for measuring the zoonotic potential of an animal TSE under field exposure conditions is unknown. During the past decades, many protective measures have been successfully implemented to protect cattle from the spread of c-BSE, and some of these measures have been extended to sheep and goats to protect from scrapie according to the principle of precaution. Since cases of c-BSE have greatly reduced in number, those protective measures are currently being challenged and relaxed in the absence of other known zoonotic animal prion disease. We recommend that risk managers should be aware of the long term potential risk to human health of at least certain scrapie isolates, notably for lymphotropic strains like the classical scrapie strain used in the current study. Relatively high amounts of infectivity in peripheral lymphoid organs in animals infected with these strains could lead to contamination of food products produced for human consumption. Efforts should also be maintained to further assess the zoonotic potential of other animal prion strains in long-term studies, notably lymphotropic strains with high prevalence like CWD, which is spreading across North America, and atypical/Nor98 scrapie (Nor98)50 that was first detected in the past two decades and now represents approximately half of all reported cases of prion diseases in small ruminants worldwide, including territories previously considered as scrapie free... Even if the prevailing view is that sporadic CJD is due to the spontaneous formation of CJD prions, it remains possible that its apparent sporadic nature may, at least in part, result from our limited capacity to identify an environmental origin.
Like lambs to the slaughter
* 31 March 2001 *
Debora MacKenzie *
Magazine issue 2284
Suspect symptoms
What if you can catch old-fashioned CJD by eating meat from a sheep infected with scrapie?
Exclusive from New Scientist magazine
Four years ago, Terry Singeltary watched his mother die horribly from a degenerative brain disease. Doctors told him it was Alzheimer's, but Singeltary was suspicious.
The diagnosis didn't fit her violent symptoms, and he demanded an autopsy. It showed she had died of sporadic Creutzfeldt-Jakob disease.
Photo: Murdo McLeod
Most doctors believe that sCJD is caused by a prion protein deforming by chance into a killer. But Singeltary thinks otherwise.
He is one of a number of campaigners who say that some sCJD, like the variant CJD related to BSE, is caused by eating meat from infected animals.
Their suspicions have focused on sheep carrying scrapie, a BSE-like disease that is widespread in flocks across Europe and North America.
Now scientists in France have stumbled across new evidence that adds weight to the campaigners' fears.
To their complete surprise, the researchers found that one strain of scrapie causes the same brain damage in mice as sCJD.
"This means we cannot rule out that at least some sCJD may be caused by some strains of scrapie," says team member Jean-Philippe Deslys of the French Atomic Energy Commission's medical research laboratory in Fontenay-aux-Roses, south-west of Paris.
Hans Kretschmar of the University of Göttingen, who coordinates CJD surveillance in Germany, is so concerned by the findings that he now wants to trawl back through past sCJD cases to see if any might have been caused by eating infected mutton or lamb.
Brain damage Scrapie has been around for centuries and until now there has been no evidence that it poses a risk to human health.
But if the French finding means that scrapie can cause sCJD in people, countries around the world may have overlooked a CJD crisis to rival that caused by BSE.
Deslys and colleagues were originally studying vCJD, not sCJD.
They injected the brains of macaque monkeys with brain from BSE cattle, and from French and British vCJD patients. The brain damage and clinical symptoms in the monkeys were the same for all three.
Mice injected with the original sets of brain tissue or with infected monkey brain also developed the same symptoms.
As a control experiment, the team also injected mice with brain tissue from people and animals with other prion diseases: a French case of sCJD; a French patient who caught sCJD from human-derived growth hormone; sheep with a French strain of scrapie; and mice carrying a prion derived from an American scrapie strain.
As expected, they all affected the brain in a different way from BSE and vCJD.
But while the American strain of scrapie caused different damage from sCJD, the French strain produced exactly the same pathology. Multiple strains "The main evidence that scrapie does not affect humans has been epidemiology," says Moira Bruce of the neuropathogenesis unit of the Institute for Animal Health in Edinburgh, who was a member of the same team as Deslys.
"You see about the same incidence of the disease everywhere, whether or not there are many sheep, and in countries such as New Zealand with no scrapie," she says.
In the only previous comparisons of sCJD and scrapie in mice, Bruce found they were dissimilar. But there are more than 20 strains of scrapie, and six of sCJD.
"You would not necessarily see a relationship between the two with epidemiology if only some strains affect only some people," says Deslys.
Bruce is cautious about the mouse results, but agrees they require further investigation.
Other trials of scrapie and sCJD in mice, she says, are in progress.
Deformed proteins People can have three different genetic variations of the human prion protein, and each type of protein can fold up two different ways.
Kretschmar has found that these six combinations correspond to six clinical types of sCJD: each type of normal prion produces a particular pathology when it spontaneously deforms to produce sCJD. But if these proteins deform because of infection with a disease-causing prion, the relationship between pathology and prion type should be different, as it is in vCJD.
"If we look at brain samples from sporadic CJD cases and find some that do not fit the pattern," says Kretschmar, "that could mean they were caused by infection."
There are 250 deaths per year from sCJD in the US, and a similar incidence elsewhere.
Singeltary and other US activists think that some of these people died after eating contaminated meat or "nutritional" pills containing dried animal brain.
Governments will have a hard time facing activists like Singeltary if it turns out that some sCJD isn't as spontaneous as doctors have insisted.
Deslys's work on macaques also provides further proof that the human disease vCJD is caused by BSE.
And the experiments showed that vCJD is much more virulent to primates than BSE, even when injected into the bloodstream rather than the brain. This, says Deslys, means that there is an even bigger risk than we thought that vCJD can be passed from one patient to another through contaminated blood transfusions and surgical instruments.
More at: Proceedings of the National Academy of Sciences (vol 98, p 4142)
Correspondence about this story should be directed to letters@newscientist.com 1900 GMT, 28 March 2001
* New Scientist
http://www.newscientist.com/dailynews/news.jsp?id=ns9999560
http://www.newscientist.com/article.ns?id=mg16922840.300
http://www.newscientist.com/article.ns?id=mg16922840.300
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies
Author
Location: Virus and Prion Research
Title: The pathogenesis, detection, and control of scrapie in sheep Author
 | CASSMANN, ERIC - Oak Ridge Institute For Science And Education (ORISE) |
| Greenlee, Justin |
Submitted to: American Journal of Veterinary Research Publication Type: Review Article Publication Acceptance Date: 12/4/2019 Publication Date: 7/20/2020 Citation: Cassmann, E.D., Greenlee, J.J. 2020. The pathogenesis, detection, and control of scrapie in sheep. American Journal of Veterinary Research. 81(7):600-614. https://doi.org/10.2460/ajvr.81.7.600. DOI: https://doi.org/10.2460/ajvr.81.7.600 Interpretive Summary: Technical Abstract: Sheep scrapie is a fatal neurologic disease that is caused by an infectious misfolded protein called a prion. The prion protein is encoded by an endogenous gene, PRNP, and it resides in high concentrations within the central nervous system. A broad range of functions for the prion protein have been uncovered, but the entire range of function is undetermined. In the misfolded conformation, prion accumulation results in neurodegeneration. There are several naturally occurring polymorphisms in the PRNP gene, and there is a strong correlation between disease susceptibility and the PRNP genotype. The cornerstone of many scrapie eradication programs is selection of scrapie resistant genotypes. The transmission of scrapie often occurs between sheep in the periparturient period when lambs are the most susceptible due to higher densities of gut-associated lymphoid tissue. Subsequently, prions are disseminated to the lymphoid system and spread to the central nervous system. The shedding of prions occurs prior to the onset of clinical signs. In contrast to classical scrapie, atypical scrapie is a spontaneous form of scrapie that occurs in individual older animals within a flock. It is not considered to be naturally infectious. This review addresses the current diagnostic modalities and techniques for studying scrapie in sheep. The examination of disease characteristics aims to identify the etiology and diagnose prion diseases. Scrapie transmission to other species including deer has been demonstrated experimentally, as well as the transmission of non-scrapie prion diseases to sheep. Finally, the effectiveness of the United States scrapie eradication program is reviewed. Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research Title: Scrapie in white-tailed deer: a strain of the CWD agent that efficiently transmits to sheep? Author
Research Project: Pathobiology, Genetics, and Detection of Transmissible Spongiform Encephalopathies Location: Virus and Prion Research Title: Sheep are susceptible to the agent of TME by intracranial inoculation and have evidence of infectivity in lymphoid tissues Author
|
P.9.21 Molecular characterization of BSE in Canada
Jianmin Yang1, Sandor Dudas2, Catherine Graham2, Markus Czub3, Tim McAllister1, Stefanie Czub1 1Agriculture and Agri-Food Canada Research Centre, Canada; 2National and OIE BSE Reference Laboratory, Canada; 3University of Calgary, Canada
Background: Three BSE types (classical and two atypical) have been identified on the basis of molecular characteristics of the misfolded protein associated with the disease. To date, each of these three types have been detected in Canadian cattle. Objectives: This study was conducted to further characterize the 16 Canadian BSE cases based on the biochemical properties of there associated PrPres.
Methods: Immuno-reactivity, molecular weight, glycoform profiles and relative proteinase K sensitivity of the PrPres from each of the 16 confirmed Canadian BSE cases was determined using modified Western blot analysis.
Results: Fourteen of the 16 Canadian BSE cases were C type, 1 was H type and 1 was L type. The Canadian H and L-type BSE cases exhibited size shifts and changes in glycosylation similar to other atypical BSE cases. PK digestion under mild and stringent conditions revealed a reduced protease resistance of the atypical cases compared to the C-type cases. N terminal- specific antibodies bound to PrPres from H type but not from C or L type. The C-terminal-specific antibodies resulted in a shift in the glycoform profile and detected a fourth band in the Canadian H-type BSE.
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. * It also suggests a similar cause or source for atypical BSE in these countries.
*** It also suggests a similar cause or source for atypical BSE in these countries. ***
Discussion: The C, L and H type BSE cases in Canada exhibit molecular characteristics similar to those described for classical and atypical BSE cases from Europe and Japan. *** This supports the theory that the importation of BSE contaminated feedstuff is the source of C-type BSE in Canada. *** It also suggests a similar cause or source for atypical BSE in these countries. ***
see page 176 of 201 pages...tss
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply;
*** Singeltary reply ; Molecular, Biochemical and Genetic Characteristics of BSE in Canada Singeltary reply;
MONDAY, OCTOBER 05, 2020
USA, UK, JAPAN, CJD TSE PRION STATISTICS UPDATE OCTOBER 2020
SATURDAY, SEPTEMBER 26, 2020
A nationwide trend analysis in the incidence and mortality of Creutzfeldt–Jakob disease in Japan between 2005 and 2014 with increasing trends of incidence and mortality
snip...
Overall, the AAPCs of age-adjusted CJD-associated mortality rates rose significantly over the study period (3.2%; 95% confidence interval [CI] 1.4–5.1%). The AAPC of the age-adjusted incidence rates also increased (overall 6.4%; 95% CI 4.7–8.1%). The CJD-associated increases in the mortality and incidence rates were especially prominent among adults over the age of 70 years. Given this trend in aging of population, the disease burden of CJD will continue to increase in severity. Our findings thus recommend that policymakers be aware of the importance of CJD and focus on preparing to address the increasing prevalence of dementia.
snip...
Volume 26, Number 8—August 2020
Sporadic Creutzfeldt-Jakob Disease among Physicians, Germany, 1993–2018 high proportion of physicians with sCJD were surgeons
THURSDAY, JULY 02, 2020
Variant Creutzfeldt–Jakob Disease Diagnosed 7.5 Years after Occupational Exposure
Diagnosis and Reporting of Creutzfeldt-Jakob Disease
Singeltary, Sr et al. JAMA.2001; 285: 733-734. Vol. 285 No. 6, February 14, 2001 JAMA Diagnosis and Reporting of Creutzfeldt-Jakob Disease
To the Editor:
In their Research Letter, Dr Gibbons and colleagues1 reported that the annual US death rate due to Creutzfeldt-Jakob disease (CJD) has been stable since 1985. These estimates, however, are based only on reported cases, and do not include misdiagnosed or preclinical cases. It seems to me that misdiagnosis alone would drastically change these figures. An unknown number of persons with a diagnosis of Alzheimer disease in fact may have CJD, although only a small number of these patients receive the postmortem examination necessary to make this diagnosis. Furthermore, only a few states have made CJD reportable. Human and animal transmissible spongiform encephalopathies should be reportable nationwide and internationally.
Terry S. Singeltary, Sr Bacliff, Tex
1. Gibbons RV, Holman RC, Belay ED, Schonberger LB. Creutzfeldt-Jakob disease in the United States: 1979-1998. JAMA. 2000;284:2322-2323.
Terry S. Singeltary Sr.
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