Species-specific identification of Mycobacterium leprae by PCR-restriction fragment length polymorphism analysis of the hsp65 gene.

PCR-restriction fragment length polymorphism analysis (PRA) of the hsp65 gene present in all mycobacteria was used in the present investigation to characterize Mycobacterium leprae. Bacilli were extracted and purified from different organs from experimentally infected armadillos and nude mice (Swiss mice of nu/nu origin). A total of 15 samples were assayed in duplicate, and the results were compared with those obtained for a total of 147 cultivable mycobacteria representing 34 species. Irrespective of its origin or viability, M. leprae strains from all the samples were uniformly characterized by two fragments of 315 and 135 bp upon BstEII digestion and two fragments of 265 and 130 bp upon HaeIII digestion. PRA is a relatively simple method and permits the conclusive identification of M. leprae to the species level.