DIAGNOSIS AND EPIDEMIOLOGY OF BOVINE TUBERCULOSIS USING MOLECULAR BIOLOGICAL APPROACHES

Conventional methods for diagnosis and epidemiological studies of bovi ne tuberculosis and other mycobacterial diseases are far from ideal. I n the last twelve years, molecular biology has provided new approaches which have enabled detailed studies to be made of the molecular chara cteristics of Mycobacterium bovis, the causative organism of bovine tu berculosis. These characteristics have been investigated for their pot ential use in diagnosis and epidemiological studies. Restriction fragm ent analysis of genomic DNA from isolates of M. bovis has provided a h ighly discriminatory typing system which has been used extensively for epidemiological studies. DNA elements in M. bovis have been investiga ted for their potential use in diagnostic assays based on the polymera se chain reaction. Individual antigens of M. bovis and their reactive epitopes have been identified and investigated for their usefulness in both serological and T cell assays of animal infection. Serological a ssays have proven disappointing and the full potential of T cell assay s has yet to be determined. Currently, T cell assays based on recombin ant antigens have not been as sensitive as those based on natural anti gens.