A simple and rapid molecular typing of Mycobacterium tuberculosis by polymerase chain reaction

As an attempt to evaluate a molecular tool for fingerprinting clinical isolates of Mycobacterium tuberculosis, a PCR-based typing method, so-called 'outward-PCR', was employed in this study. Outward-PCR used in this study was designed to amplify the sequences in-between two IS6110 elements. A total of 81 M. tuberculosis isolates including 73 Korean and 8 Philippine isolates were subjected to PCR amplification and the profiles of the agarose gel electrophoresis were analyzed. In brief, under the PCR conditions used in this study, the 81 clinical isolates were classified into 33 distinctive sub-groups. Among these, 5 sub-groups represented major clusters with 7 to 11 clinical isolates belonging to each sub-group. The banding patterns were clear and reproducible, implying that this rapid and simple PCR-based typing method can be a valuable tool for typing clinical isolates of M. tuberculosis.