[Diagnosis of tuberculosis by specific DNA amplification directly in samples]

The polymerase chain reaction (PCR was used to identify M. tuberculosis in specimens from patients with suspected pulmonary tuberculosis. A segment of the IS 6110 sequence and of the Cro EL gene were amplified and identified by hybridization with specific probes labeled with peroxidase. The results are in agreement with those obtained using standard microbiological techniques or clinical criteria. The PCR method allowed the detection of M. tuberculosis in 22 out of 58 samples that were acid fast staining negative. The number of patients with at least one positive sample by PCR was much higher in the group with suspicion of tuberculosis (14/28) than in the control group (3/23). This demonstrates the possibility of using PCR technology in endemic areas for tuberculosis.