An evaluation of the identification technics with IS6110 and Mt308 used as molecular markers for Mycobacterium tuberculosis strains isolated in Romania]

During the past years, new diagnostic technologies based on DNA methods including PCR, were developed in the aid of tuberculosis control. Among several DNA sequences, an insertion sequence IS6110, found to be specific to mycobacteria belonging to M. tuberculosis complex were used. However, recent studies showed the absence of this IS6110 in 3-4% of M. tuberculosis strains isolated from patients of Vietnamese origin. In order to evaluate the frequency of IS6110 among a series of strains isolated in Romania, we have performed the PCR technique for amplification of 2 DNA specific regions of M. tuberculosis complex. The sequences of primers were as shown before (Guesdon et al., 1990). For this study, 219 strains have been isolated from tuberculous patients, in "Marius Nasta" Institute of Bucharest, Romania. We have shown that genomic DNA from 3.6% of 219 strains evaluated in our study do not contain the IS6110 sequence and could determine some identification problems when this molecular sequence is targeted.