DNA Analysis of Tuberculosis: Diagnosis and Prevention

Abstract

The continued threat of tuberculosis (TB) to animals and humans is complicated by inefficient or ineffective methods of diagnosis and prevention. The high similarity among mycobacteria makes differentiation of strains and species difficult and laborious. Members of the Mycobacterium tuberculosis complex, which include the primary agents of human and bovine tuberculosis, share over 90% DNA identity and are indistinguishable by most modem methods. Additionally, the current vaccine for TB is of questionable efficacy. In this study we demonstrate the use of Random Amplified Polymorphic DNA (RAPD) as a means of typing TB isolates and as the potential source of a Mycobacterium bovis-specific PCR assay, arising from a species-specific polymorphism upstream of an acyl-CoA synthase. We also have developed a technique for the identification of antigenic recombinant polypeptide sequences from M. bovis that may be of potential worth as vaccines, on the basis of delayed-type hypersensitivity (DTH) responses by infected cattle.