[Detection of Mycobacterium tuberculosis complex with polymerase chain reaction (PCR)]

248 respiratory specimens were examined using by Nested-PCR and by conventional methods (solid and liquid media). 54 specimens were culture-positive for M. tuberculosis, 51 of these were detected by PCR and conventional methods, whereas 3 were missed by PCR and 15 were only positive by PCR. 12 of the 15 culture-negative specimens derived from patients under treatment for tuberculosis. The 3 specimens, which are PCR negative could also be detected after modification of the method. The very high sensitivity depends on the high positive rate (21.8%) of the investigated specimens, so it is necessary to look also for other than pulmonary specimens, but it seems that his Nested-PCR is a highly specific and sensitive method for detecting of M. tuberculosis.