Detection of Mycobacterium tuberculosis DNA in blood of patients with acute pulmonary tuberculosis by polymerase chain reaction and non-isotopic hybridisation assay

The detection of Mycobacterium tuberculosis DNA in peripheral blood mononuclear cells (PBMC) by PCR and non-isotopic hybridisation assay was evaluated for the laboratory diagnosis of pulmonary M. tuberculosis infection. The PCR technique was based on the presence of IS6120, a DNA sequence specific for M. tuberculosis, and performed on PBMC from 30 patients belonging to the fifth group of the American Thoracic Society (ATS) classification of tuberculosis. The identification of amplification products was confirmed after electrophoresis by hybridisation with a non-isotopic probe in a DNA enzyme immunoassay (DEIA). Of the 30 blood samples studied by the PCR-DEIA technique, 26 gave positive results and four gave negative results. Blood samples from 30 subjects in a control group were negative by this technique. The data suggest that PCR-DEIA of blood may provide a sensitive, specific and useful means of diagnosing mycobacterial infection.