Abstract
The first part of the thesis describes the characterization of 19 kDa antigen from M. bovis BCG. The gene was expressed in E. coli and was detected using the monoclonal antibody CMA134.1. It was shown to be inducible in E. coli by performing Western blot analysis of induced and non-induced lysogens. The complete nucleotide sequence of the gene was determined and shown to be identical to that of 19 kDa gene from M. tuberculosis. This gene has the potential to be used as a diagnostic tool for the early detection of bovine tuberculosis. The second part of the thesis describes an attempt to clone, characterize and sequence the two genes, dihydrofolate reductase (DHFR) and thymidylate synthase (TS) from M. tuberculosis. Polymerase chain reaction technique was used to amplify the coding DNA sequences and the amplified DNA product of the reaction was used as the probe to screen the genomic library of M. tuberculosis. Putative genes for dihydrofolate reductase and thymidylate synthase were isolated from the genomic library. Both of these putative genes failed to complement the E. coli deficient strains of DHFR and TS genes. The complete nucleotide sequence of both these genes was determined. CLUSTAL analysis of both sequences showed only low homology with published Dihydrofolate reductase and Thymidylate synthase sequences.