Bovine spongiform encephalopathy

Activities in 2009

Bovine spongiform encephalopathy

Dr Stefanie Czub

CFIA Lethbridge Laboratory, P.O.Box 640 (Township Road 9-1)

Lethbridge/Alberta T1J 3Z4, Canada

Tel.: +1(403) 382-5549, Fax: +1(403)382-5583

Summary of general activities related to the disease

  1. Test(s) in use/or available for the specified disease at your laboratory

The Canadian reference laboratory (RL) performs Immunohistochemistry (IHC) and/or SAF Immunoblot for the confirmation of BSE. In addition, the Hybrid Western Blot and several rapid tests for BSE are part of the confirmatory schedule. Different rapid tests (n=6) are implemented and one is used for BSE surveillance within the laboratory.

Test / For / Specificity / Total
Prionics-Check PrioStrip / surveillance / BSE / 7124
IHC / confirmation / BSE / 1
SAF Immunoblot / confirmation / BSE / 1

Hybrid Western Blot

/ confirmation / BSE / 1

BioRad TeSeE Elisa

/ confirmation / BSE / 1

Prionics-Check Western

/ confirmation / BSE / 1

Prionics-Check PrioStrip

/ confirmation / BSE / 1
  1. Production and distribution of diagnostic reagents

For quality assurance and quality control purposes, proficiency panels for BSE rapid tests and IHC are distributed biannually to the laboratories of the Canadian BSE network (n=8) and to the national reference laboratories of Australia, China and the USA. The panel consists of Scrapie-positive and bovine negative brain homogenates (n=10) for the respective rapid tests and of unstained Chronic Wasting Disease and Scrapie-positive and unstained bovine negative brain sections for the IHC.

Activities specifically related to the mandate
of OIE Reference Laboratories

The Canadian RL performs the serial release testing of individual rapid tests series used by the network laboratories for BSE surveillance including one ELISA and one lateral flow immunoasay. Panels consist of 16 or 18 members respectively; the BSE positive members are of Canadian, French, German and Swiss origin. The BSE-negative panel members are Canadian, French and Swiss samples.

As part of the ISO 17025 certification, the Canadian RL participates in ring trials for BSE surveillance provided by the German TSE reference Laboratory (Friedrich-Loeffler-Institute). The ring trials monitor the laboratory’s performance in a rapid western blot, a lateral flow immunoassay and in one ELISA. In addition, one proficiency panel for the performance of the IHC was received by the CRL (VLA Weybridge).

Brain homogenates from German H- and L-type atypical BSE caseshave been received from the Friedrich-Loeffler-Institute for intracerebral and peroral challenge of calves. The purpose of this experiment is to define SRMs in atypical BSE.

3.International harmonisation and standardisation of methods for diagnostic testing or the production and testing of vaccines

Brain homogenates from the Canadian H-type atypical BSE and breed-matching negative controls weredistributed to the CEA Turino and CIDC-Lelystad/Netherlands for molecular characterization and comparison. H-type homogenate distributed to the Friedrich-Loeffler-Institute/Germany and the National Institute for Animal Health/Prion Disease Research Center/Japan was used for mouse and cattle inoculation studies.

The RL inoculated i.c. five cattle with either the Canadian H-type atypical BSE or BSE-negative bovine brain-material. Material and samples from this reference bank are available to interested parties.

Five cattle were sacrificed with clinical BSE, the incubation times ranging between 24 to 28 months post inoculation. These animals had been inoculated intra cerebrally with Canadian field cases (case #1, #2, #3). Tissues, blood and other samples are available for interested parties.

A project was started to determine the detection limit of the tests used in the Canadian BSE surveillance and for BSE confirmation. The performances of the BioRad TeSeE ELISA, IDEXX HerdChek BSE, Prionics-Check PrioStrip and Prionics-Check Western rapid tests were compared to the SAF Immunoblot and the BioRad confirmatory Western Blot. As one approach recommended by the OIE, this was done using end-point dilution analysis of samples from known positive animals (our experimentally infected cattle), to define the penultimate dilution of sample in which the analyte is no longer detectable, or at least, is indistinguishable from the activity of a negative sample. BSE positive brain samples were diluted in negative bovine brain. The results will be made available via peer reviewed publication.

4.Preparation and supply of international reference standards for diagnostic tests or vaccines

None

5.Research and development of new procedures for diagnosis and control

The RL is involved in ante-mortem test development for BSE using urine as a matrix. This approach is researching biomarkers for their potential use in ante-mortem tests.

The RL leads an international research group on a project focused on a comprehensive risk assessment of CWD transmission to humans using non-human primates.

The RL developed a procedure for a rapid discrimination and confirmation between BSE and other endemic TSEs, especially Chronic Wasting Disease in cattle. The procedure is based on IHCand on a western blot platform using discriminating antibodies.

In addition, EFSA approved rapid tests for BSE (n=4) were subjected to a suitability testing for the use in bison (Bison bison). Performance criteria included diagnostic sensitivity and specificity in comparison to IHC.

6.Collection, analysis and dissemination of epizootiological data relevant to international disease control

Data collected, analyzed and provided via BSE surveillance testing (n= 7124). The RL confirmed one case of BSE in 2009.

7.Provision of consultant expertise to OIE or to OIE Members

Expertise provided via the review of the BSE chapter, email contacts, scientific and technical training on-site and in-house (see: 8).

8.Provision of scientific and technical training to personnel from other OIE Members

Scientific and technical training was provided to two pathologists/laboratory scientists from Costa Rica (SENASA/University) for 3 and 12 weeks, respectively (January to March 2009). Training included laboratory techniques, pathological diagnosis, and quality management system in laboratories working with prions.

Scientific and technical training was provided to two pathologists/laboratory scientists from the Philippines for 4weeks (April–May 2009). Training included laboratory techniques, pathological diagnosis and quality management system in laboratories working with prions.

Scientific training was provided for a technical cooperation entitled “ Strengthening of the prevention system of BSE and the adoption of the good practices of animal”. The related workshop “Training Laboratory Techniques for BSE” was organized by FAO & OIRSA in Panama City on July 7-10, 2009. Trainees included professionals from Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Dominican Republic and Cuba (~25participants).

9.Provision of diagnostic testing facilities to other OIE Members

None

10.Organisation of international scientific meetings on behalf of OIE or other international bodies

Scientific training was provided for a technical cooperation entitled “Strengthening of the prevention system of BSE and the adoption of the good practices of animal”. The related workshop “Training Laboratory Techniques for BSE” was organized by FAO & OIRSA in Panama City on July 7-10, 2009. Trainees included professionals from Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Dominican Republic and Cuba (~25participants).

11.Participation in international scientific collaborative studies

Start of an international collaboration with the German TSE reference Laboratory (Friedrich-Loeffler-Institute) on the identification of Specific Risk Material in cattle challenged with H- and l-type BSE (Health Canada funded project).

12.Publication and dissemination of information relevant to the work of OIE (including list of scientific publications, internet publishing activities, presentations at international conferences)

Presentations including national and international conferences and meetings

L. Lamoureux, S. Simon, M. Plews, M. Stobart, J. C. Graham, S. Czub, M. Groschup. D. Knox: Characterization of a BSE Biomarker, PrP Canada, Edmonton, March 1 - 3, 2009.

M. Plews, S. Simon, D. Parchaliuk, R. Mitchel, D. Boreham, H. Wyatt, S. Czub, D. Knox: The influence of low dose radiation on oxidative stress and prion pathogenesis. PrP Canada, Edmonton, March 1 - 3, 2009.

J. Yang, S. Dudas, C. Graham, M. Czub, T. McAllister, S. Czub: Molecular Characterization of BSE in Canada. PrP Canada, Edmonton, March 1 - 3, 2009.

J. Moser, S. Czub, M. Friztler: Overexpression of GW182 protein and GW bodies in BSE-positive bovine obex imprints. PrP Canada, Edmonton, March 1 - 3, 2009.

S. Dudas, C. Graham, S. Czub, S. Moore, L. Guan: Identification of differentially expressed genes in CWD-infected elk. PrP Canada, Edmonton, March 1 - 3, 2009.

T. Reuter, B.H. Gilroyed, T.W. Alexander, G. Mitchell, A. Balachandran, S. Czub, T.A. McAllister: Prion protein detection via direct immunoquantitative real-time PCR. Prion2009 meeting, Porto Carras/Greece, September 23-25, 2009.

J.D. Knox, M. Plews, L. Lamoureux, S. Simon, M. Stobart, M. Groschup, C. Graham, S. Czub: A comparative analysis of biomarkers in two cohorts of BSE infected cattle. Prion2009 meeting, Porto Carras/Greece, September 23-25, 2009.

J. Yang, S. Dudas, C. Graham, M. Czub, T. McAllister, S. Czub: Molecular characterization of BSE in Canada. Prion2009 meeting, Porto Carras/Greece, September 23-25, 2009.

Other communications

S. Czub: Canadian BSE surveillance and other BSE safeguards, Technical visit of Panama to Canada, Lethbridge, April 6th, 2009.

S. Dudas, S. Czub: Research at the BSE Reference Laboratory, CFIA TSE workshop, Ottawa, April 28- 29, 2009.

S. Czub: Canadian BSE surveillance and other BSE safeguards, Technical visit of South KoreanLobbyists to Canada, Lethbridge, December 10th, 2009.

13.Inscription of diagnostic kits on the OIE Register

i)Did you participate in expert panels for the validation of candidate kits for inscription on the OIE Register? If yes, for which kits?

None

ii)Did you submit to the OIE candidate kits for inscription on the OIE Register? If yes, for which kits?

None

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Annual reports of OIE Reference Laboratories and Collaborating Centres, 20091