Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis

Thesis (PhD (Biomedical Sciences. Molecular Biology and Human Genetics))--University of Stellenbosch, 2007.

Saved in:
Bibliographic Details
Main Author: Johnson, Rabia
Other Authors: Victor, T. C.
Format: Thesis
Language:English
Published: Stellenbosch : University of Stellenbosch 2008
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613916620652544
access_status_str Open Access
author Johnson, Rabia
author2 Victor, T. C.
author_browse Johnson, Rabia
Victor, T. C.
author_facet Victor, T. C.
Johnson, Rabia
author_sort Johnson, Rabia
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (PhD (Biomedical Sciences. Molecular Biology and Human Genetics))--University of Stellenbosch, 2007.
format Thesis
id oai:scholar.sun.ac.za:10019.1/1265
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:43:44.982Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2008
publishDateRange 2008
publishDateSort 2008
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/1265 Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis Johnson, Rabia Victor, T. C. Warren, R. M. University of Stellenbosch. Faculty of Health Sciences. Dept. of Biomedical Sciences. Molecular Biology and Human Genetics. Mycobacterium drug resistance Transcriptomics Beijing epedemiology Beijing epedemiology Thesis (PhD (Biomedical Sciences. Molecular Biology and Human Genetics))--University of Stellenbosch, 2007. One of the aims of direct observed therapy strategy implemented by the World Health Organization was to prevent the development of drug resistant tuberculosis. However, in recent years a dramatic increase and spread in multidrug resistant tuberculosis has been observed. In this study, a molecular epidemiological approach was used to understand and rapidly detect drug resistance in high incidence tuberculosis communities of the Western Cape, South Africa. Previous studies showed that, drug resistant tuberculosis occurs as a result of spontaneous mutations in particular genes. Using molecular techniques, we developed an algorithm to rapidly detect isoniazid, rifampicin and ethambutol drug resistance in tuberculosis patients from a short term mini culture. Rapid detection of drug resistance is important to prevent future transmission events. In addition, accurate ethambutol resistance testing is of particular importance, since treatment of patients infected with multidrug resistant strains with second line anti-tuberculosis drugs depend on the ethambutol test results. In a comprehensive study, we found that the algorithm performs well when compared to the traditional culture method currently used by the routine laboratories. However, the results showed that more then 90 % of ethambutol resistance is missed by the routine laboratories. This has important implications for the tuberculosis control program, since patients infected with the drug resistant strain may be on inappropriate treatment. In this study, we found that certain strains have a selective advantage to become drug resistant and transmit and this implies that they are more virulent and fit than other strains. This observation has also been made for strains within the same genotype family. The more transmissible drug resistant strains cause large drug resistant outbreaks. This study highlights the complexity of the drug resistant epidemic, and confirms that it is a major problem in local communities. Application of molecular methods has provided us with tools to study how resistance might develop. We have demonstrated how we made use of a newly developed method to detect a multidrug resistant outbreak in the study community. The applications of transcriptomics identified several genes that might play a role in isoniazid resistance. Using this data a model was proposed whereby isoniazid resistant strains can compensate for the toxic effect of the drug. Application of comparative genomics by whole genome sequencing will be used to assist us in the further understanding of the mechanisms of drug resistance. This study also conclude that we should continue in our attempts to develop faster diagnostics for both first and second line drugs and that we must not loose site that all of this research must in the end benefit the patients. Doctoral 2008-03-27T12:05:19Z 2010-06-01T08:16:49Z 2008-03-27T12:05:19Z 2010-06-01T08:16:49Z 2007-12 Thesis http://hdl.handle.net/10019.1/1265 en University of Stellenbosch 1080060 bytes application/pdf application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Mycobacterium drug resistance
Transcriptomics
Beijing epedemiology
Beijing epedemiology
Johnson, Rabia
Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis
title Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis
title_full Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis
title_fullStr Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis
title_full_unstemmed Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis
title_short Understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in Mycobacterium tuberculosis
title_sort understanding the mechanisms of drug resistance in enhancing rapid molecular detection of drug resistance in mycobacterium tuberculosis
topic Mycobacterium drug resistance
Transcriptomics
Beijing epedemiology
Beijing epedemiology
url http://hdl.handle.net/10019.1/1265
work_keys_str_mv AT johnsonrabia understandingthemechanismsofdrugresistanceinenhancingrapidmoleculardetectionofdrugresistanceinmycobacteriumtuberculosis