The bacteriological diagnosis of NTM is based on isolation of these organisms from diagnostic specimens using standard mycobacteriology laboratories techniques. Frequency of isolation and semi-quantitative assessment of the bacteriological load in the specimen is necessary in cases when differentiation between invasive disease and colonization is an issue, as addressed below in cases of pulmonary NTM disease. A special issue is the bacteriological diagnosis of disseminated NTM disease, which is based on isolation of NTM from blood. The most convenient approach is to submit a blood sample collected in a sodium polyanetholesulphonate (SPS)-containing yellow-top vacutainer to the laboratory. Such a sample can be used for either culture isolation only and/or quantitation of the bacterial load in blood (quantitative culture) as a tool for monitoring the patient's response to therapy.37,38 It is important that a properly processed specimen is inoculated into both liquid medium and agar plates rather than only on the Löwenstein-Jensen slant, which is the least favourable for cultivation of NTM.