Mycobacterium species identification in an acute hospital: towards rapid identification, and improved epidemiology, using novel Mass Spectrometry analysis / James Anthony O Connor.
By: O'Connor, James Anthony [author]
.
Material type: 
BookSeries: Ph.D - Biological Sciences.Publisher: Cork : Cork Institute of Technology, 2018Description: various pagings : illustrations (some color) tables, maps ; 30 cm.Content type: text Media type: unmediated Carrier type: volumeSubject(s): Mycobacteria -- Identification -- Hospitals | Mycobacterium tuberculosis | Time-of-flight mass spectrometry | Mass spectrometryDDC classification: THESES PRESS Dissertation note: Thesis Cork Institute of Technology, 2018. Abstract: 'Mycobacterium 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 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<0.01). A multicentre evaluation (14 laboratories across 10 EU/EEA countries) of the new protocol saw a mean identification of 90% of isolates tested. A comprehensive validation of MALDI-tof for the identification of clinical mycobacteria was undertaken; including an extensive comparison with the widely used, GenoType CM method. There was 97% concordance between methods for a diverse population of mycobacteria (n=117). The results demonstrate that MALDI-tof is a reliable means by which to identify clinical mycobacteria. The current study also investigated the efficacy of MALDI-tof as a typing tool for Mycobacterial-Interspersed Repetitive Unit-Variable Number of Tandem Repeats (MIRU-VNTR) typed MTC isolates. The results determined an optimal algorithm for processing mass spectra, however, there did not appear to be sufficient discrimination between types to allow for reliable real-time epidemiological outbreak investigations using MALDI-tof'. Abstract
| Item type | Current library | Call number | Status | Date due | Barcode | Item holds |
|---|---|---|---|---|---|---|
| Reference | MTU Bishopstown Library Thesis | THESES PRESS (Browse shelf(Opens below)) | Reference | 00181375 |
Thesis Cork Institute of Technology, 2018.
Includes bibliographical references.
'Mycobacterium 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 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<0.01). A multicentre evaluation (14 laboratories across 10 EU/EEA countries) of the new protocol saw a mean identification of 90% of isolates tested. A comprehensive validation of MALDI-tof for the identification of clinical mycobacteria was undertaken; including an extensive comparison with the widely used, GenoType CM method. There was 97% concordance between methods for a diverse population of mycobacteria (n=117). The results demonstrate that MALDI-tof is a reliable means by which to identify clinical mycobacteria. The current study also investigated the efficacy of MALDI-tof as a typing tool for Mycobacterial-Interspersed Repetitive Unit-Variable Number of Tandem Repeats (MIRU-VNTR) typed MTC isolates. The results determined an optimal algorithm for processing mass spectra, however, there did not appear to be sufficient discrimination between types to allow for reliable real-time epidemiological outbreak investigations using MALDI-tof'. Abstract