Date of Award


Document Type

Doctoral Thesis

Degree Name

Doctor of Philosophy


Biological Sciences

First Advisor

Dr. Brigid Lucey

Second Advisor

Prof. Jim O'Mahony


Mycobacteria are a heterogeneous group of bacteria that cause a wide spectrum of disease, including Tuberculosis (TB), the single biggest killer worldwide. The genus also incorporates over 170 nontuberculosis (NTM) species, many of which are opportunistic pathogens. The aim of this project was to ascertain the burden of mycobacterial disease in the region and to determine the efficacy of Matrix-Assisted Laser Desorption/Ionisation time-of-flight (MALDI-tof) mass spectrometry (MS) for novel uses as a rapid identification method for clinical mycobacteria and as a typing tool for Mycobacterium tuberculosis complex isolates. A five-year retrospective epidemiological study of the region was conducted, the first study of its kind in fifteen years. It revealed a decrease of over 40% in the rate of TB in the intervening fifteen-year period. The study also highlighted a four-fold increase in the rate of NTM disease. This study examined preanalytical variables and recommended methods of extraction of mycobacterial proteins for MALDI-tof analysis and found major shortcomings with three extraction methods tested with very high rates of nonidentification. This study saw the first description of a novel two-step cell disruption protocol. The new protocol resulted in a significant improvement in identifications over the recommended protocol (97% of isolates compared to 75% of isolates, p

Access Level