[Modern laboratory diagnostics for mycobacteria]

Early diagnosis of tuberculosis is one of the most important tools for the interruption of transmission chains and the elimination of the disease. Even today the final diagnosis of tuberculosis has to be confirmed finally by the bacteriological detection of mycobacteria in sputa or other specimens (1 - 4). The suspicion of tuberculosis can be corroborated by chest X-ray and clinical symptoms. Immunologically based assays like the tuberculin skin-test and the new interferon-gamma-release-assays enable the diagnosis of tuberculosis infection, but cannot distinguish between active and latent tuberculosis. [nl]Therefore, the main bacteriological tools in tuberculosis diagnostics remain the following: the microscopic detection of acid-fast bacteria in the specimens, the cultural isolation of the bacteria in liquid media and subsequent identification with molecular methods and the rapid direct identification with nucleic acid amplification techniques (NAT). Drug susceptibility testing has been enhanced by application of the more rapid liquid media and, at least for some drugs, the time to detection can be further shortened by the usage of molecular-based techniques.