EVALUATION OF MTP40 GENOMIC FRAGMENT AMPLIFICATION FOR SPECIFIC DETECTION OF MYCOBACTERIUM-TUBERCULOSIS IN CLINICAL SPECIMENS

A PCR assay based on the species-specific mtp40 genomic fragment was d eveloped for the specific detection and identification of Mycobacteriu m tuberculosis in different uncultured clinical specimens. The aim of the study was to evaluate the clinical applicability of this target DN A in comparison with those of conventional microbiological methods and to compare the results obtained with those obtained after amplificati on with the IS6110 repetitive element. Discrepant results were interpr eted in conjunction with the patients' clinical data, medical historie s, and responses to therapy. A total of 172 specimens from 162 patient s with respiratory symptoms were tested, 101 specimens were obtained f rom 92 patients clinically suspected of having tuberculosis, and 71 sp ecimens were obtained from 70 patients without known mycobacterial inf ection. The results of our study suggest that PCR amplification with t he mtp40 genomic fragment provides a highly sensitive and specific tec hnique for the detection of M. tuberculosis strains in clinical sample s. It allows for the differentiation between M. tuberculosis and other related mycobacteria, including M. bovis, and is more specific than t he IS6110 target. For these and other reasons, we propose that the mtp 40 assay is a possible alternative for the specific direct detection o f M. tuberculosis in clinical laboratories.