MYCOBACTERIUM-LEPRAE ISOLATES FROM DIFFERENT SOURCES HAVE IDENTICAL SEQUENCES OF THE SPACER REGION BETWEEN THE 16S AND 23S RIBOSOMAL-RNA GENES

To test for genotypic variations between different isolates of Mycobac terium leprae, the causative agent of leprosy, the 282 bp spacer regio n between the 16S and 23S rRNA genes was amplified using PCR, and subm itted to single-strand conformation polymorphism (SSCP) analysis. The procedure was optimized using four modified spacer fragments, containi ng mutations at one, three, four and six positions, respectively. Seve nty-five M. leprae isolates from different sources, including isolates from leprosy patients. healthy individuals, armadillos and mouse foot pads were identical in the SSCP analysis. DNA sequencing and restricti on enzyme analysis performed on four and 40 samples, respectively, con firmed the results obtained with SSCP analysis.