[DNA diagnostics of mycobacterial infection]

A diagnosis of mycobacterial infection may be suggested by a patient's symptoms, clinical or radiographic findings. However, the definite diagnoses of mycobacterial infections are dependent upon the isolation and identification of etiologic agents. Recently, nontuberculous mycobacteria are being increasingly recognized as the causes of lung diseases. Therefore, it is important to rapidly differentiate nontuberculous mycobacteria from Mycobacterium tuberculosis, since treatments, epidemiologic implications, and prognoses due to these various causative organisms may be considerably different. The isolation of mycobacteria from clinical samples takes several weeks for culture on presently available solid media, and biochemical identifications take additional several weeks after isolation of mycobacteria. Rapid, sensitive, and specific tests for detection of the organism as species in clinical specimens have been a long-standing goal. Recently, new diagnostic procedures based on molecular biology have been developed. The identifications of the species by DNA probes and PCR and a new test by means of luciferase reporter phages were discussed.