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Improved Diagnostics for Cattle - SE3005

Description
The national cattle testing programme currently utilises the tuberculin test for the detection of bovine tuberculosis. However, the tuberculin test can lack both sensitivity and specificity, and alters the immune status of the animal. It also results in a significant number of cattle with inconclusive test results, which, due to the altered immune status caused by the tuberculin skin-test, cannot be re-tested within 60 days. This proposal addresses section H (paragraph 71) of the MAFF Animal Health and Welfare Research Requirements and specifically the problem of inconclusive reactors (IR), where an alternative immunological read-out system like the BOVIGAM interferon- assay - which would allow earlier re-testing after skin testing - could be highly beneficial to quickly resolve an inconclusive test status. In addition, a test of higher specificity might reduce the absolute numbers of IR, thus reducing the need for re-testing. This proposal builds on advances made in previous ROAME-funded projects SE0112 and SE0114. The aim is to develop diagnostic tests which are more specific than existing assays, can detect infection earlier in cattle than the tuberculin test, and do not require long intervals between testing. Such improved tests would be intended for use in TB control programmes as an adjunct to tuberculin testing in key problem areas, particularly in resolving inconclusive reactions.
Objective
Obj. No. Completed by date Description

01
31/01/2000
To establish whether antigen and peptide cocktails improve specificity of IFN- assay, and to compare with other alternative immunological measurements.


02
31/03/2001
To apply new protein- and peptide-based reagents to inconclusive reactors.



03
31/01/2001
To assess whether an MPB70 or MPB83 ELISA system will help predict the outcome of re-testing of inconclusive reactors and cattle with high risk of disease transmission.


04
30/04/2001
To produce MPB83 M. smegmatis and to test whether there are differences in the antigenicity to the corresponding E. coli recombinant in cattle and guinea pigs.


05
30/11/1999
To determine active components in PPD and to study effects of chemical modifications on PPD potency in guinea pigs and cattle.


06
30/07/2001
To determine the effects of post-translational modifications on antigenicity using MPB83 as model antigen.


07
31/03/2002
To assess the role of adjuvants and delivery systems to improve the potency of protein- or peptide-based diagnostic reagents.


08
31/03/2002
To maintain close collaboration with Dr J. Pollock’s group (DANI, Stormont, Northern Ireland).


09
31/03/2002
To prepare manuscripts for scientific publications.


10
31/03/2002
To prepare annual and final reports.



11
31/12/2000
To assess whether factors within the blood influence the preformance of assays to detect tuberculosis based on cellular immune responses.

Project Documents
• Final Report : Improved diagnostics for cattle   (468k)
• Executive Summary : Executive Summary for SE3005   (129k)
Time-Scale and Cost
From: 1999

To: 2002

Cost: £511,347
Contractor / Funded Organisations
Veterinary Laboratories Agency
Keywords
Animal Health              
Biotechnology              
Bovine Tuberculosis              
Control              
Plants and Animals              
Zoonoses              
Fields of Study
Animal Health