To date, 128 mycobacterial species have been characterised, ranging from non-pathogenic to pathogenic for humans. Molecular methods contributed significantly to the identification of the species, replacing conventional laborious methods. In this thesis, the design and application of a genus-specific real-time PCR, for the rapid detection of non-tuberculous mycobacteria in clinical materials, was described. The technique was extremely useful for the rapid detection of the slowgrowing Mycobacterium species. Addition of species-specific probes to the ITS assay, identified M. haemophilum to be present in previously undiagnosed skin inflammation and resulted in the recognition of M. haemophilum as the second most common mycobacterial species causing lymphadenitis. Subsequent Amplified Fragment Length Polymorphism analysis of M. haemophilum isolates showed this species to posses an extremely low mutation rate. Also, M. haemophilum lymphadenitis cases are suspected to have a common source, most likely piped water, in contrast to M. avium infections, which appear to originate from variable environmental sources as was underscribed by Restriction Fragment Length Polymorphism analysis. Contamination with saprophytic mycobacterial DNA is problematic for the current NTM detection in clinical materials. This and other bottlenecks in the molecular diagnostics of NTM were addressed in this thesis as well.UBL - phd migration 201
