Evaluation of the insertion-sequence-6110- based polymerase chain reaction for detection of pathogenic mycobacteria

The insertion sequence IS6110 is a mobile genetic element typical for Mycobacterium tuberculosis complex (MTC) bacteria. Due to its narrow host range, this insertion element can be used for rapid identifi cation of pathogenic mycobacteria. The aim of this study was to evaluate the diagnostic value of the IS6110 element in comparison with common molecular and microbiological methods. A total of 170 clinical specimens from tuberculosis (TB) patients were tested for the presence of IS6110 by polymerase chain reaction (PCR). Detection of MTC by IS6110–PCR revealed the highest number of MTC positive specimens (40.6 %) in comparison to commercial LCx assay (27.6 %) and to the commonly used methods for estimating bacteria growth: BACTEC system (20.6 %) and on Lowenstein-Jensen medium (15.3 %). IS6110-PCR was shown to be a rapid and specifi c method for identifi cation of the Mycobacterium tuberculosis complex. It was found to be especially useful for confi rming diagnosis in cases of smear- and culture-negative results, when the clinical expansion of tuberculosis was obvious.