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Development of a unique means of detecting and proving illegal administration of recombinant somatotropin in dairy cows

Final Report Summary - UNIQUE-CHECK (Development of a unique means of detecting and proving illegal administration of recombinant somatotropin in dairy cows)

Grant agreement no.: 230667
Project acronym: Unique-Check
Project full title: Development of a unique means of detecting and proving
illegal administration of recombinant somatotropin in
dairy cows
Funding Scheme: Collaborative Project
FP7 Marie Curie
Industry-Academia Partnership and Pathways (IAPP)
Duration of the project: 48 Months
Start date of the project: 1st June 2009
End date of the project: 31st May 2013
Project co-ordinator name: Dr Chen SITU
Project co-ordinator organisation: Queen’s University Belfast, United Kingdom
Tel: + 44 (0) 2890 976546
Fax: + 44 (0) 2890 976513

Executive summary
Background: The use of recombinant bovine somatotropin (rBST), also known as growth hormone to increase milk production, has been a common practice in the United States (US) and many other countries since the commercial product became available in 1994. Such use has however never been approved in the European Union (EU) and it was banned in 1999 due to concerns on animal health and welfare, food safety and quality, and human health implications associated with the administration of rBST in dairy cows. Though the administration and marketing of rBST are banned in the EU, imports of milk and dairy products from rBST treated animals to the EU are unaffected. Therefore, methods are required for unequivocal identification of rBST-treated animal products. Moreover, the commercial rBST is extremely similar to the endogenous growth hormone with only one different amino acid residue at the N-terminus of the protein. There are no direct methods available to date that are capable of distinguishing and detecting rBST in dairy products. The present project brought together four partners of academia and industry and aimed to deliver a unique procedure to rapidly detect and unambiguously prove the administration of rBST in dairy cows.

Project objectives: The objectives of the project were to produce specific binders that can recognise the rBST and to use these binders to develop a panel of immunoassays (ELISA, dipstick, biosensor) for rapid and reliable screening of rBST in milk. Development of immunoassay would be supported and backed up by the sophisticated chemical confirmatory method utilising the most advanced mass spectrometry instrumentations. The overall objective was to, by the use of new technologies and a wide range of expertise; deliver a means of screening and confirmation the presence of this unwanted growth promoter in milk.

Results and achievements: For decades, the production of specific antibodies directed towards rBST has not been successfully accomplished due to the highly similarity between rBST and endogenous BST. We have successfully demonstrated that by using different approaches, production of specific antibodies towards rBST is possible. We have also reported, for the first time, using the specific antibody, a high selectivity towards rBST in a competitive antigen-coated ELISA format. We have also demonstrated the suitability of biosensor technology platform as a sensitive and label-free immunodiagnostic tool for quantification of rBST. We have explored different approaches for production of specific binders to rBST (eg phage peptides). The LFD format for detection of rBST has been completely established in a full assembled device in cassettes and in a dipstick format. The final LFD prototype will be produced using the specific monoclonal antibodies currently being developed. A confirmatory method based on LC-MS/MS for the detection of rbST residues in milk samples has successfully been developed and validated according to Dec 2002/657/EC. This method enables sensitive and specific detection of the hormone of interest which opens the way for controlling the origin of dairy products.

Impact of the project results: Administration of recombinant bovine somatotropin (rBST) in dairy cows is known to significantly raise the amount of IGF-1, a protein in milk that has been linked to the development of several cancers in human. Such practice is prohibited in EU and many countries in the world. However, it is practically impossible to tell if the milk we consume has been produced using this growth-enhancing hormone which has been claimed to increase milk yield for at least 10% daily in cows. The present project has, by the use of new technologies, delivered sensitive analytical methods to detect and confirm the presence of this unwanted growth promoter in milk. This will greatly impact on both food safety and consumer confidence in food choice for “green products”. The project will also contribute to the current EU-wide efforts of promoting animal health and welfare. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has scheduled to re-evaluate rbST during its next meeting in November 2013. The present method may constitute an interesting tool for “update the exposure assessment based on any new occurrence data in food”.