IS 6110 Insertions in Mycobacterium tuberculosis : Predominantly into Coding Regions

This is the authors' abstract. We don't add key points for this paper.

We read with interest the recent publication by Benjamin et al. (2) regarding the characterization of IS6110insertion sites in the direct repeat (DR) region of Mycobacterium tuberculosis. This topical and relevant study described the dissection of a single molecular event leading to an altered DNA fingerprint pattern that was detected by two different strain genotyping systems, namely, IS6110 DNA fingerprinting and spoligotyping. It was shown that a single IS6110transposition event in the DR region disrupted one of the spoligotyping primer regions, thereby resulting in simultaneous changes in the IS6110 fingerprint and spoligotype pattern. The authors rightly recommended that some caution should be applied to the interpretation of similar, but nonidentical, IS6110 DNA fingerprint and spoligotype patterns. In addition, the results corroborated the occurrence of IS6110 preferential integration loci, as previously identified by a number of investigators (3, 5, 7).