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From: TSS ()
Subject: Rapid Typing of Transmissible Spongiform Encephalopathy Strains with Differential ELISA
Date: March 27, 2008 at 11:50 am PST

Volume 14, Number 4–April 2008
Research
Rapid Typing of Transmissible Spongiform Encephalopathy Strains with
Differential ELISA
Stéphanie Simon,* Jérôme Nugier,* Nathalie Morel,* Hervé Boutal,* Christophe
Créminon,* Sylvie L. Benestad,† Olivier Andréoletti,‡ Frédéric Lantier,§
Jean-Marc Bilheude,¶ Muriel Feyssaguet,¶ Anne-Gaëlle Biacabe,# Thierry
Baron,# and Jacques Grassi*
*Commissariat à l'Energie Atomique, Gif-sur-Yvette, France; †National
Veterinary Institute, Oslo, Norway; ‡Institut National de la Recherche
Agronomique-Ecole Nationale Vétérinaire de Toulouse, Toulouse, France;
§Infectiologie Animale et Santé Publique, Tours, France; ¶Bio-Rad,
Marnes-la-Coquette, France; and #Agence Française de Sécurité Sanitaire des
Aliments, Lyon, France


Abstract

The bovine spongiform encephalopathy (BSE) agent has been transmitted to
humans, leading to variant Creutzfeldt-Jakob disease. Sheep and goats can be
experimentally infected by BSE and have been potentially exposed to natural
BSE; however, whether BSE can be transmitted to small ruminants is not
known. Based on the particular biochemical properties of the abnormal prion
protein (PrPsc) associated with BSE, and particularly the increased
degradation induced by proteinase K in the N terminal part of PrPsc, we have
developed a rapid ELISA designed to distinguish BSE from other scrapie
strains. This assay clearly discriminates experimental ovine BSE from other
scrapie strains and was used to screen 260 transmissible spongiform
encephalopathy (TSE)–infected small ruminant samples identified by the
French active surveillance network (2002/2003). In this context, this test
has helped to identify the first case of natural BSE in a goat and can be
used to classify TSE isolates based on the proteinase K sensitivity of
PrPsc.


SNIP...


Analysis of Nor98 Isolates

The typing test was used to analyze 18 sheep isolates from Norway (Table 3).
Ratios were almost impossible to calculate because of the large decrease in
signal in A´ conditions, as shown in Figure 5, panel A for 3 isolates. Only
1 sample (Lavik) showed characteristics of a conventional scrapie isolate,
providing an A/A´ ratio of 0.84 (Figure 5, panel A), a normalized ratio of
0.11, and a Western blot profile close to that of a French scrapie isolate
(Figure 4, panel B, lanes 3 and 9; Figure 5, panel B, lanes 2 and 4). Other
samples had a pattern that included a 12-kDa band (Figure 5, panel B)
(19,22,34), characteristic of the Nor-98 strain.

After adapting the conditions of the PK treatment in the second set of
measurements (A´ conditions), we observed (see legend, Figure 6) a much
lower A/A´ ratio for those Nor-98, which enables discrimination of highly
sensitive PK samples (nos. 24 and 26, Appendix Figure 2 and Table 3) to
mildly sensitive PK samples (nos. 8, 11, 16, and 22).

Discussion

When this study was initiated, no case of natural BSE in small ruminants was
recorded, and only a few experimental ovine BSE samples were available, all
belonging to the same PrP genotype (ARQ/ARQ), and mainly from a first
passage. The possible impact of the genotype, the route of infection, and
the number of passages on the biochemical properties of PrPres associated
with the BSE strain are poorly understood. Now, further data suggest that,
at least during the second passage in sheep, the biochemical properties
(glycoform pattern in brain) of the BSE agent are unchanged (35,36). In this
study using our ELISA, small ruminant BSE samples clearly behaved
differently from conventional scrapie samples. However, slight differences
may exist (see ARQ/ARQ vs. ARR/ARR genotype in Appendix Figure 1). We do not
know whether these findings reflect differences in the PK sensitivity of
PrPres associated with these genotypes or the influence of different
tissues.

The main difficulty encountered for the development of a typing test is
evaluation of its specificity and sensitivity. In the current study, we
unambiguously identified all 37 experimental ovine BSE samples from 25
sheep, including 10 from a second passage. There are few data describing the
molecular features of PrPres associated with experimental BSE in goats
(37,38). In the framework of the French scrapie strain-typing network, 18
goats were analyzed by this ELISA, and 2 appeared compatible with
experimental ovine and caprine BSE. One of them (Ch636), when analyzed with
other molecular typing tests, appeared indistinguishable from experimental
BSE and was later confirmed as the first natural case of BSE in a goat (1),
after experimental transmission in wild-type and transgenic mice. The second
BSE compatible sample (TR041528) was later clearly identified as a case of
atypical scrapie as defined by its migration pattern (34). All these data
suggest a good sensitivity for our test, which unambiguously identified all
cases of experimental BSE in the sheep and goats tested, as well as the only
natural case identified to date in a goat.

Another key point during the development of this test was to ensure good
reproducibility because this parameter clearly influences both sensitivity
and specificity. Ratios obtained for the classic scrapie control were highly
reproducible, whereas ratios measured for the experimental BSE in sheep and
the intermediate scrapie control varied much more, leading to an overlap of
the 95% confidence interval (Table 1). To minimize interassay variations,
the ratio obtained for each unknown sample was thus normalized by taking as
reference the ratio measured for the ovine BSE sample (Figure 2, panel C,
and Figure 3) in the same experiment. This enabled us to define the range of
normalized ratio compatible with BSE as the mean of experimental ovine BSE ±
2s on the basis of reproducibility experiments recorded in Table 1. This
range was experimentally determined between 0.7 and 1.3, leading to 3
categories for field samples: conventional scrapie (ratio <0.7), compatible
with BSE (0.7 1.3).

Only 10 (3.8%) of the 260 samples analyzed in the framework of the French
epidemiologic surveillance network during 2002–2003 gave a ratio compatible
with BSE. Of the 10 BSE suspected samples, only 1 goat sample (Ch636) was
later confirmed as a true natural BSE case (1). This result indicates that
the specificity of this test is not that good because 9 false-positive
results were recorded in 260 samples (specificity 96.5%). However, the test
appears useful since it excluded the presence of BSE for most field samples,
thus restricting the use of more specific but time-consuming methods, like
experimental transmission in mice, to a small number of isolates. Moreover,
in a single screening, this test classified all TSE-infected isolates as a
function of their PK resistance and thus provided a rapid classification of
sheep isolates according to this criterion. The test could also be modified,
by adjusting the range of PK sensitivity, to classify Nor-98 isolates.

All these data demonstrate that this ELISA-based typing test is suitable for
a routine analysis of field samples, as assessed by the positive evaluation
from the European Commission as one of the tests recommended to identify the
possible presence of BSE in small ruminant flocks
(http://eur-lex.europa.eu/LexUriServ/site/en/oj/2005/l_010/l_01020050113en00
090017.pdf). These typing tests are mainly designed to identify the BSE
strain in small ruminant flocks. They are performed exclusively in national
reference laboratories and based on Western blot techniques. In this
context, the present ELISA is one of the secondary tests to be used to
confirm BSE suspicion. We believe it will help clarify the status of these
unusual isolates.

Acknowledgments


snip...end

http://www.cdc.gov/eid/content/14/4/608.htm?s_cid=eid608_e


http://madcowtesting.blogspot.com/2008/03/rapid-typing-of-transmissible.html


http://madcowtesting.blogspot.com/


High incidence of subclinical infection of lymphoid tissues in
scrapie-affected sheep flocks

Journal Archives of Virology
Publisher Springer Wien
ISSN 0304-8608 (Print) 1432-8798 (Online)
Issue Volume 153, Number 4 / April, 2008
Category Original Article
DOI 10.1007/s00705-008-0035-8
Pages 637-644
Subject Collection Biomedical and Life Sciences
SpringerLink Date Tuesday, January 29, 2008

Gudmundur Georgsson1 , Jona Adalheidur Adolfsdottir1, Astridur Palsdottir1,
Einar Jorundsson1, 3, Sigurdur Sigurdarson2, 4 and Stefania Thorgeirsdottir1

(1) Institute for Experimental Pathology, University of Iceland, Keldur
v/Vesturlandsveg, 112 Reykjavík, Iceland
(2) Laboratory of Chief Veterinary Officer, Keldur, Reykjavík, Iceland
(3) Present address: Ministry of Education, Science and Culture,
Solvholsgata 4, 101 Reykjavík, Iceland
(4) Present address: Agricultural Authority of Iceland, Austurvegur 64, 800
Selfoss, Iceland

Received: 12 November 2007 Accepted: 27 December 2007 Published online: 29
January 2008

Abstract Prion diseases are characterized by a long incubation period. In
scrapie, sheep may incubate and spread the infection for several years
before clinical signs evolve. We have previously studied the occurrence of
subclincal infection in the brain. Now, we have studied the occurrence of
subclinical infection in the brain and several lymphoid tissues in two
scrapie-affected Icelandic sheep flocks by immunohistochemistry for PrPSc, a
molecular marker for infectivity, and correlated this with results of PrP
genotyping. At culling, one flock had one confirmed scrapie case, while the
other flock had two. Analysis of 106 asymptomatic sheep by immunostaining
for PrPSc revealed that the incidence of subclinical infection was 58.3% in
one flock and 42.5% in the other. PrPSc was only detected in lymphoid
tissues. The youngest positive sheep were 4 months old. PrP genotyping
showed that over 90% of the sheep were of a genotype which is moderately
sensitive to infection and may delay neuroinvasion. Our results show that
asymptomatic sheep may spread the infection during the long incubation
period of several years, which constitutes an important obstacle in the
eradication of scrapie. Our findings indicate that contamination of the
environment plays an important part in sustaining the infection.

----------------------------------------------------------------------------
----


Gudmundur Georgsson
Email: ggeorgs@hi.is


http://www.springerlink.com/content/u761171744280806/

http://scrapie-usa.blogspot.com/2008/03/high-incidence-of-subclinical-infection.html


SCRAPIE USA UPDATE MONTHLY REPORT JANUARY 2008


prepared February 20, 2008

Infected and Source Flocks

There were 27 scrapie infected and source flocks with open statuses (Figure
3) as of January 31, 2008. Two new source flocks and one new infected flock
were reported in January (Figure 4) with a total of 22 reported for FY 2008
(Figure 5). ....


snip...


Positive Scrapie Cases

As of January 31, 2008, 58 new scrapie cases have been confirmed and
reported by the National Veterinary Services Laboratories (NVSL) in FY 2008
(Figure 7). Of these, 52 were field cases and 6* were Regulatory Scrapie
Slaughter Surveillance (RSSS) cases (collected in FY 2008 and reported by
February 20, 2008). There were 8 positive cases for January which are
depicted in Figure 8. Seventeen cases of scrapie in goats have been
confirmed by NVSL since implementation of the regulatory changes in FY 2002
(Figure 9). The most recent positive goat cases were from the SAME HERD and
WERE BOTH CONFIRMED IN JANAURY 2008.


snip...


Caprine Scrapie Prevalence Study (CSPS)

CSPS was initiated in May 2007 to estimate the national prevalance of
scrapie in adult goats at slaughter. If no scrapie is found we will be able
to conclude that the prevalence in goats is greater than zero and less than
0.1 percent. AS of January 31, 2008, 2,942 goats have been sampled for
scrapie testing (1,515 in FY 2007 and 1,427 in FY 2008). Collection numbers
by quarter in FY 2008 is shown in Chart 8. To date, no goats have tested
positive for scrapie as part of this surveillance program. HOWEVER, THREE
POSITIVE GOATS have been identified this fiscal year through field
investigations. One was a clinical suspect submitted for testing and THE
OTHER TWO WERE MEMBERS OF THE OF THE BIRTH HERD OF THE CLINICAL CASE.


snip...


please see full text ;


http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps

ATYPICAL NOR-98 SCRAPIE LOCATION UPDATE ON 5 DOCUMENTED CASES THIS YEAR ;


The flocks of origin are WY, CO, CA, IN, and MN.


personal communication USDA et al. ...TSS

snip...

INFECTED AND SOURCE FLOCKS AS of August 31, 2007, there were 33 scrapie
infected and source flocks with open statuses (Figure 3). Five new source
flocks and one new infected flock were reported n August (Figure 4) with a
total of 64 reported for FY 2007(Figure 5).


snip...


IN FY 2007 TWO FIELD CASES, ONE VALIDATION CASE, AND TWO RSSS CASES WERE
CONSISTENT WITH NOR-98 SCRAPIE. ...


(BRINGS A TOTAL OF 5 NOR-98 CASES DOCUMENTED IN 2007 IN USA. ...TSS)


http://www.aphis.usda.gov/animal_health/animal_diseases/scrapie/downloads/monthly_scrapie_rpt.pps

> If atypical scrapie is found in the United States, an additional control
program may be necessary

> but it is likely that no changes in the current control program will be
needed.


http://www.usaha.org/committees/reports/2006/report-scr-2006.pdf

>>>For the period of time from January 1, 2005, until October 15, 2005,
there were 23 instances of discrepancies in results from 35 flocks. Of those
23 instances, 14 were caused by laboratory error (paperwork or sample
mix-up), 3 results from field error, 5 were not completely resolved, and 1
originated from the use of a non-approved laboratory for the first test. As
a result of inconsistencies, one laboratory’s certification was revoked by
APHIS-VS. <<<


http://www.usaha.org/committees/reports/2005/report-scr-2005.pdf


SCRAPIE TYPICAL AND ATYPICAL USA


http://nor-98.blogspot.com/


http://scrapie-usa.blogspot.com/


> -------- Original Message --------
> Subject: USA BIO-RADs INCONCLUSIVEs
> Date: Fri, 17 Dec 2004 15:37:28 -0600
> From: "Terry S. Singeltary Sr."
> To: susan_berg@bio-rad.com
>
>
>
> Hello Susan and Bio-Rad,
>
> Happy Holidays!
>
> I wish to ask a question about Bio-Rad and USDA BSE/TSE testing
> and there inconclusive. IS the Bio-Rad test for BSE/TSE that complicated,
> or is there most likely some human error we are seeing here?
>
> HOW can Japan have 2 positive cows with
> No clinical signs WB+, IHC-, HP- ,
> BUT in the USA, these cows are considered 'negative'?
>
> IS there more politics working here than science in the USA?
>
> What am I missing?
>
>
>
> -------- Original Message --------
> Subject: Re: USDA: More mad cow testing will demonstrate beef's safety
> Date: Fri, 17 Dec 2004 09:26:19 -0600
> From: "Terry S. Singeltary Sr."
> snip...end
>
>
> Experts doubt USDA's mad cow results

snip...END

WELL, someone did call me from Bio-Rad about this,
however it was not Susan Berg.
but i had to just about take a blood oath not to reveal
there name. IN fact they did not want me to even mention
this, but i feel it is much much to important. I have omitted
any I.D. of this person, but thought I must document this ;

Bio-Rad, TSS phone conversation 12/28/04

Finally spoke with ;


Bio-Rad Laboratories
2000 Alfred Nobel Drive
Hercules, CA 94547
Ph: 510-741-6720
Fax: 510-741-5630
Email: XXXXXXXXXXXXXXXXXX

at approx. 14:00 hours 12/28/04, I had a very pleasant
phone conversation with XXXX XXXXX about the USDA
and the inconclusive BSE testing problems they seem
to keep having. X was very very cautious as to speak
directly about USDA and it's policy of not using WB.
X was very concerned as a Bio-Rad official of retaliation
of some sort. X would only speak of what other countries
do, and that i should take that as an answer. I told X
I understood that it was a very loaded question and X
agreed several times over and even said a political one.

my question;

Does Bio-Rad believe USDA's final determination of False positive,
without WB, and considering the new
atypical TSEs not showing positive with -IHC and -HP ???

ask if i was a reporter. i said no, i was with CJD Watch
and that i had lost my mother to hvCJD. X did not
want any of this recorded or repeated.

again, very nervous, will not answer directly about USDA for fear of
retaliation, but again said X tell
me what other countries are doing and finding, and that
i should take it from there.
"very difficult to answer"

"very political"

"very loaded question"

outside USA and Canada, they use many different confirmatory tech. in
house WB, SAF, along with
IHC, HP, several times etc. you should see at several
talks meetings (TSE) of late Paris Dec 2, that IHC- DOES NOT MEAN IT IS
NEGATIVE. again, look what
the rest of the world is doing.
said something about Dr. Houston stating;
any screening assay, always a chance for human
error. but with so many errors (i am assuming
X meant inconclusive), why are there no investigations, just false
positives?
said something about ''just look at the sheep that tested IHC- but were
positive''. ...


TSS

-------- Original Message --------
Subject: Your questions
Date: Mon, 27 Dec 2004 15:58:11 -0800
From: To: flounder@wt.net

Hi Terry:

............................................snip Let me know your phone
number so I can talk to you about the Bio-Rad BSE test.
Thank you

Regards

Bio-Rad Laboratories
2000 Alfred Nobel Drive
Hercules, CA 94547
Ph: 510-741-6720
Fax: 510-741-5630
Email: =================================


END...TSS


######### https://listserv.kaliv.uni-karlsruhe.de/warc/bse-l.html ##########

Executive Summary

In June 2005, an inconclusive bovine spongiform encephalopathy (BSE) sample
from November 2004, that had originally been classified as negative on the
immunohistochemistry test, was confirmed positive on SAF immunoblot (Western
blot). The U.S. Department of Agriculture (USDA) identified the herd of
origin for the index cow in Texas; that identification was confirmed by DNA
analysis. USDA, in close cooperation with the Texas Animal Health Commission
(TAHC), established an incident command post (ICP) and began response
activities according to USDA’s BSE Response Plan of September 2004. Response
personnel removed at-risk cattle and cattle of interest (COI) from the index
herd, euthanized them, and tested them for BSE; all were negative. USDA and
the State extensively traced all at-risk cattle and COI that left the index
herd. The majority of these animals entered rendering and/or slaughter
channels well before the
investigation began. USDA’s response to the Texas finding was thorough and
effective.


http://www.aphis.usda.gov/lpa/issues/bse/epi-updates/bse_final_epidemiology_report.pdf


Report on Food & Drug Administration Dallas District Investigation of
Bovine Spongiform Encephalopathy Event in Texas 2005

Executive Summary:

On June 24, 2005, USDA informed FDA that a cow in Texas tested positive for
Bovine Spongiform Encephalopathy (BSE). Information provided by APHIS was
that the BSE positive cow was born and raised in a herd in Texas and was
approximately 12 years old. The animal was sampled for BSE at a pet food
plant in Texas on November 15, 2004, as part of USDA’s enhanced surveillance
program.

http://www.fda.gov/cvm/texasfeedrpt.htm

Texas even had a 'secret' test that showed that mad cow positive;


experimental IHC test results, because the test was

not a validated procedure, and because the two

approved IHC tests came back negative, the results

were not considered to be of regulatory significance

and therefore were not reported beyond the

laboratory.


• A Western blot test conducted the week of

June 5, 2005, returned positive for BSE.

http://www.usda.gov/documents/vs_bse_ihctestvar.pdf

48 hr BSE confirmation turnaround took 7+ months to confirm this case, so
the BSE MRR policy could be put into place. ...TSS

-------- Original Message --------Subject: re-USDA's surveillance plan for
BSE aka mad cow diseaseDate: Mon, 02 May 2005 16:59:07 -0500From: "Terry S.
Singeltary Sr."To: paffairs@oig.hhs.gov, HHSTips@oig.hhs.gov,
contactOIG@hhsc.state.tx.us

Greetings Honorable Paul Feeney, Keith Arnold, and William Busbyet al at
OIG, ...............snip...


There will be several more emails of my research to follow.

I respectfully request a full inquiry into the cover-up of TSEsin the United
States of America over the past 30 years. Iwould be happy to testify...

Thank you,I am sincerely,


Terry S. Singeltary Sr.P.O. Box 42Bacliff, Texas USA 77518
xxx xxx xxxx


Date: June 14, 2005 at 1:46 pm PST

In Reply to: Re: Transcript Ag. Secretary Mike Johanns and Dr. John
Clifford, Regarding further analysis of BSE Inconclusive Test Results posted
by TSS on June 13, 2005 at 7:33 pm:

Secretary of Agriculture Ann M. Veneman resigns Nov 15 2004, three dayslater
inclusive Mad Cow is announced. June 7th 2005 Bill Hawks UnderSecretary for
Marketing and Regulatory Programs resigns. Three days later same mad cow
found in November turns out to be positive. Both resignationare unexpected.
just pondering...TSS

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

Subject: Re: BSE 'INCONCLUSIVE' COW fromTEXAS ???Date: Mon, 22 Nov 2004
17:12:15 -0600From: "Terry S. Singeltary Sr."To: Carla EverettReferences:
<[log in to unmask]><[log in to unmask] us>

Greetings Carla,still hear a rumor;

Texas single beef cow not born in Canada no beef entered the food chain?

and i see the TEXAS department of animal health is ramping up
forsomething,but they forgot a url for update?

I HAVE NO ACTUAL CONFIRMATION YET...

can you confirm???terry

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

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

Subject: Re: BSE 'INCONCLUSIVE' COW fromTEXAS ???Date: Fri, 19 Nov 2004
11:38:21 -0600From: Carla EverettTo: "Terry S. Singeltary Sr."References:
<[log in to unmask]>

The USDA has made a statement, and we are referring all callers to the
USDAweb site. We have no informationabout the animal being in Texas.

Carla

At 09:44 AM 11/19/2004, you wrote:

>Greetings Carla,

>>i am getting unsubstantiated claims of this BSE 'inconclusive' cow is from

>TEXAS. can you comment on this either way please?

>>thank you,

>Terry S. Singeltary Sr.>>

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

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

Subject: Re: BSE 'INCONCLUSIVE' COW fromTEXAS ???Date: Mon, 22 Nov 2004
18:33:20 -0600From: Carla EverettTo: "Terry S. Singeltary Sr."References:
<[log in to unmask]><[log in to unmask] us><[log in to unmask]> <[log in to
unmask]us> <[log in to unmask]>

our computer department was working on a place holder we could post
USDA'sannouncement of any results. There are no results to be announced
tonight byNVSL, so we are back in a waiting mode and will post the
USDAannouncement when we hear something.

At 06:05 PM 11/22/2004,

you wrote:

>why was the announcement on your TAHC site removed?

>>Bovine Spongiform Encephalopathy:

>November 22: Press Release title here

>>star image More BSE information

>>>>terry

>>Carla Everett wrote:

>>>no confirmation on the U.S.'inconclusive test...

>>no confirmation on location of animal.>>>>>>


http://madcowtesting.blogspot.com/

TSS




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