ABSTRACT
SETTING: Mycobacteriology research and service laboratories in Thailand. OBJECTIVE: To evaluate the possibility of differentiating species of mycobacteria by amplifying 16S-23S ribosomal deoxyribonucleic acid (DNA) spacer and restriction enzyme analysis of the products. DESIGN: DNA of 113 strains of mycobacteria belonging to 18 species of the genus Mycobacterium were amplified by primers PL1 (5'-GAAGTCGTAACAAGG) and PL2 (5'-CAAGGCATCCACCAT). The amplified products as well as their HaeIII-, MspI- and BstXI-digested products were visualized after agarose gel electrophoresis. RESULTS: The amplified products of rapid-growing mycobacteria were different from the slow-growing mycobacteria. The restriction profiles of members of M. tuberculosis complex were the same as each other but different from other investigated species. The restriction profiles of some species, such as M. avium, M. intracellulare and M. gordonae, were unique, while those of the other species had more than one pattern. However, the restriction profiles of most investigated species were different from each other. CONCLUSION: This preliminary study suggested that the method might be useful for species differentiation of some commonly isolated pathogenic mycobacteria.