DIFFERENTIATION OF MYCOBACTERIUM SPECIES BY RESTRICTION ENZYME ANALYSIS OF AMPLIFIED 16S-23S RIBOSOMAL DNA SPACER SEQUENCES

Setting: Mycobacteriology research and service laboratories in Thailan d. Objective: To evaluate the possibility of differentiating species o f mycobacteria by amplifying 16S-23S ribosomal deoxyribonucleic acid ( DNA) spacer and restriction enzyme analysis of the products. Design: D NA 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 HaeI II-, MspI- and BstXI-digested products were visualized after agarose g el electrophoresis. Results: The amplified products of rapid-growing m ycobacteria were different from the slow-growing mycobacteria, The res triction profiles of members of M. tuberculosis complex were the same as each other but different from other investigated species, The restr iction profiles of some species, such as M. avium, M. intracellulare a nd M. gordonae, were unique, while those of the other species had more than one pattern, However, the restriction profiles of most investiga ted species were different from each other. Conclusion: This prelimina ry study suggested that the method might be useful for species differe ntiation of some commonly isolated pathogenic mycobacteria.