| abstract |
This invention provides recombinant mycobacterium strains of pathogenic origin that have been attenuated by the inactivation of a gene coding for a metabolic protein, specifically a gene coding for a protein necessary for the biosynthesis of a purine or a pyrimidine base, and more precisely, the purC gene that codes for an enzyme of the metabolic pathway of purine biosynthesis. The recombinant mycobacterium of this invention have a reduced capacity to propagate in a mammalian host, but remain viable in the host for a period of time sufficient to induce an protective immune response against the natural pathogenic mycobacterium counterpart. |