Use of some mycobacterial peptides and recombinant proteins for diagnosis of bovine tuberculosis / Wagdy Samir Beshir Youssef ; Supervised Kamelia Mahmoud Osman , Emad Mokhtar Riad

Thesis (Ph.D.) - Cairo University - Faculty of Veterinary Medicine - Department of Microbiology

In this study, some M. bovis recombinant peptides 2recombinant early secretory antigenic target-6 (rESAT-6), recombinant major protein of M. bovis 64 (rMPB-64) and recombinant major protein of M. bovis 83 (rMPB-83)3 were cloned, expressed and purified from well identified of M. bovis strains. They were used in both serum dependent tests as ELISA and whole blood techniques; IFN- Þ assay as a diagnostic tests for tuberculosis. So, we successfully cloned and expressed the rESAT-6, rMPB-64 and rMPB-83 proteins in pure form and identified by SDS-PAGE and immunoblotting technique.They were used in skin testing in infected guinea pigs by killed M. bovis and it showed clear response using different used doses of expressed proteins as well as it was used in ELISA on 500 serum samples from tuberculin tested animals and in Gamma interferon assay on 50 tuberculin tested animals in comparison with PPD. The obtained results proved the antigenicity and immunogenicity of the recombinant antigens as they can detect cases as tuberculous positive from tuberculin negative cases by ELISA and gamma interferon assay. The sensitivity and specificity of each used test were recorded and discussed. Results showed higher sensitivity and specificity of purified recombinant proteins over PPD when used in diagnosis of bovine tuberculosis in ELISA and IFN-Þ assay and superiority of these tests over tuberculin test. It was concluded that the purified rESAT-6, rMPB-64 and rMPB-83 were implementable as a specific and sensitive antigens alternative to ordinary diagnostic PPD. It also declare that use of this antigen resulted in a marked improvement in the ELISA and IFN-Þ release among both TST negative and TST positive cattle

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