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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

The molecular epidemiology of mycobacterium tuberculosis : role in understanding disease dynamics in high prevalence settings in Southern Africa region

Chihota, Violet 03 1900 (has links)
Thesis (PhD)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The tuberculosis (TB) incidence has increased in Southern Africa and the situation is worsened by the emergence of drug-resistant Mycobacterium tuberculosis strains. Molecular biological techniques have been used to understand the disease dynamics of TB. In a series of studies we describe the use of these techniques to understand the disease dynamics of TB in Southern Africa. Using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) to characterize M. tuberculosis strains from TB patients in Zimbabwe, we identified a genotype causing a disproportionate number of TB cases. The genotype belonged to the Latin American Mediterranean (LAM) lineage and we named it the Southern Africa1 (SAF1) family and later renamed it SAF1/RDRio, also reflecting its predominance in South America. To establish if this family of strains was predominant elsewhere in Southern Africa, genotypes were compared to those from Western Cape, South Africa and Zambia. The SAF1/RDRio strains were highly prevalent in Zambia but were only a minor fraction of the strains in South Africa. The geographical distribution of SAF1/RDRio strains was determined in Gweru, Zimbabwe, and was found to be spread in high incidence areas. From these two studies it was hypothesized that certain host and bacterial factors were associated with disease due to SAF1/RDRio. Subsequently potential risk factors and clinical outcomes of disease due to SAF1/RDRio strains were explored. An association was found with smoking and cavitary pulmonary disease suggesting that SAF1/RDRio caused a more severe and highly transmissible formof TB Using IS6110-RFLP, principal genetic grouping, spoligotyping, IS6110 insertion-site mapping and variable-number tandem repeats (VNTR) typing, low IS6110 copy clade (LCC) identified in Zimbabwe were characterized and compared to the strains from Cape Town, South Africa and other regions. The LCC strains from Cape Town, South Africa, were found to have close evolutionary relationship with strains from Zimbabwe and other regions and were widely distributed suggesting they play an important role in the global TB epidemic. Observations from these studies and those from other studies led to the hypothesis that specific genotypes of M. tuberculosis predominate in regions of Southern Africa. To gain an insight on the population structure of M. tuberculosis strains in Southern Africa, spoligotyping and/or IS6110-RFLP data from eight countries were compared. This is the first study to describe the M. tuberculosis population structure in Southern Africa. Distinct genotypes were associated with specific geographic regions. These findings have important implications for TB diagnostics, anti-TB drug and vaccine development. The population structure of multidrug-resistant (MDR), pre-extensively drug-resistant (pre-XDR) and extensively drug-resistant (XDR) M. tuberculosis isolates from provinces in South Africa was also determined. This is again the first study to describe the population structure of drug-resistant M. tuberculosis in South Africa. The results also showed geographic localization of genotypes and an association with resistance class. However, decreasing strain diversity was observed as the isolates evolved from MDR-TB to XDR-TB suggesting selection for the specific genotypes. These findings highlight the importance of identifying genetic markers in drug-resistant strains, to enhance early detection of those at risk of developing XDR-TB. / AFIKAANSE OPSOMMING: Die voorkoms van tuberkulose (TB) in Suider Afrika word vererger deur stamme van Mycobacterium tuberculosis wat weerstandig is teen die beskikbare anti-tuberkulose middels. Molekulêre tegnieke word gebruik om in hierdie reeks studies die dinamika van TB in Suider Afrika te ondersoek Deur spoligotipering en IS6110 restriksie fragment lengte polimorfisme (RFLP) tegnieke te gebruik om M. tuberculosis stamme van pasiente in Zimbabwe te beskryf, het ons ‘n genotipe gevind wat ‘n buitengewone aantal TB gevalle veroorsaak het. Hierdie genotipe is deel van die internasionaal beskryfde Latyns Amerikaase en Meditereense (LAM) stam familie. Ons het dit die Suider Afrikaanse Familie1 (SAF1) genoem, maar later hernoem na SAF1/RDRio, omdat dieselfde genotipe in ook volop is in Suid Amerika. Om vas te stel of hierdie familie ook oorheesend is in die res van Suider Afrika, is dit vergelyk met beskikbare databasisse van die Wes-Kaap, Suid-Afrika en Zambië. Alhoewel SAF1/RDRio in die Wes-Kaap gevind is, dra dit slegs tot ‘n mindere mate by tot die plaaslike TB epidemie. Aan die anderkant kom SAF1/RDRio baie algemeen in Zambië voor. ‘n Verdere studie wys ook dat die SAF1/RDRio familie eweredig en wyd verspreid voorkom in hoë insidensie gebiede in Gweru, Zimbabwe. Vanuit die bevindings van hierdie 2 studies, kan ons aflei dat sekere gasheer- en bakteriële eienskappe geassosieer is met SAF1/RDRio-TB-infeksie. Hierna is potensiële risiko faktore en kliniese uitkomste van siekte as gevolg van infeksie met SAF1/RDRio ondersoek. ‘n Assosiasie met rook en kaviterende pulmonale infeksie is gevind,wat daarop dui dat SAF1/RDRio erger vorm van TB veroorsaak en hoogs oordraagbaar is. Deur gebruik te maak van IS6110- (RFLP), hoof groep groepering, spoligotipering, IS6110 invoegings kaartering en veranderlike getal tandem herhaling (VNTR) tipering kon lae IS6110 invoeginsgetal (LCC) stamme van Kaapstad, Zimbabwe en ander gebiede vergelyk word. Al die LCC stamme in die studie is evolusionêr naby verwant aan mekaar en is wyd verspreid, wat dui op hulle belangrike rol in die wêreldwye TB epidemie. Waarnemings in hierdie asook ander studies het tot die hipotese gely dat spesifieke genotipes van M. tuberculosis dominant is in verskillende gebiede van Suider Afrika. Om meer insig tot die populasie samestelling van M. tuberculosis stamme in Suider Afrika in te win is spoligotipes en RFLP-data van 8 lande vergelyk. Hierdie is die eerste studie om die populasie samestelling van M. tuberculosis in Suider Afrika te beskryf en is belangrike fir toekomstige ontwikkeling van nuwe TB diagnose tegnieke, anti-TB middels en TB entstowwe. Die populasie samestelling van multiweerstandige (MDR), pre-ekstreme weerstandige (pre-XDR) en ekstreme weerstandige (XDR) M. tuberculosis van verskillende provinsies in Suid-Afrika is ook bepaal. Hierdie studie is ook die eerste wat die populasie samestelling van weerstandige M. tuberculosis in Suid-Afrika beskryf. Die resultate wys geografiese lokalisering van genotipes en ‘n assosiasie met weerstandigheidsklas. ‘n Afname in stam diversiteit soos die isolate van MDR-TB tot XDR-TB ontwikkel, dui op seleksie van spesifieke genotipes. Hierdie bevinding lê die klem op die belangrikheid van die identifisering van genetiese merkers in weerstandige stamme om die risiko vir die ontwikkeling van XDR-TB te verminder deur vroë deteksie.
32

Tuberculose multirresistente e extensivamente resistente em área metropolitana de elevada incidência - município de Santos (SP), Brasil / Multidrug and extensively drug-resistant tuberculosis in the metropolitan area of high incidence - the city of Santos (SP), Brazil

Coelho, Andrea Gobetti Vieira 03 March 2015 (has links)
INTRODUÇÃO: A incidência de tuberculose (TB) em Santos (SP) situa-se em 73/100.000 habitantes-ano. A prevalência média de coinfecção TB/HIV é de 16%, taxas de cura e abandono de tratamento, entre casos novos são, respectivamente, 71% e 12%. Tais indicadores sugerem elevado risco para TB multidroga resistente (TBMR) no município, com incidência estimada em 1,9/100.000 habitantes-ano. OBJETIVO: Descrever e analisar o perfil de sensibilidade às drogas (TS) de primeira e segunda linha de tratamento entre pacientes com TB pulmonar (TBP), estimar a incidência de TBMR e a proporção de TB extensivamente resistente (TBXR); analisar aspectos moleculares, epidemiológicos e institucionais dos casos de TBP resistentes em Santos (SP). MÉTODOS: Estudo descritivo de uma coorte de pacientes de TBP, com início de tratamento ou retratamento entre 01 de janeiro de 2011 a 31 de dezembro de 2012. Definiu-se como caso de TBP, indivíduos com 15 anos ou mais, de ambos os sexos, residentes no município de Santos, com manifestações clínicas compatíveis com TBP e confirmação por cultura com isolamento de Mycobacterium tuberculosis. As variáveis de interesse para o estudo foram as características sociodemográficas, história atual e pregressa de TB, aspectos relativos ao tratamento, co-morbidades, ao diagnóstico e resistência a drogas. Para as análises comparativas entre proporções foram usados os testes qui-quadrado de Pearson e o Exato de Fisher e para variáveis contínuas o teste T de Student ou o de Kruskal - Wallis. Os perfis genéticos dos isoladas resistentes a ao menos uma droga foram obtidos pela técnica RLFP e analisados pelo programa Bionumerics versão 5.0 (Applied Maths - Bélgica). A descrição da distribuição espacial da TB resistentes e clusters foram feitas mediante a inserção dos casos no mapa de Santos, por endereço de residência, segundo o índice de vulnerabilidade social. RESULTADOS: Dos 263 casos de TBP selecionados, 68,4% (180/263) eram do sexo masculino, a mediana da idade foi de 38 anos, 8,7% (23/263) eram diabéticos; 20,4% (42/206) dos casos novos apresentavam ao menos um fator de risco para TBMR; destacando-se entre estes casos 10,7% (22/206) de confecção HIV/TB; 47,3% (123/260) tiveram tratamento supervisionado, 14,7% (91/617) dos contatos foram examinados, 18,6% (49/263) foram hospitalizados durante o tratamento, perfazendo uma média de 145,4 dias por paciente. Entre os casos resistentes a ao menos uma droga, a resistência à isoniazida foi 8,4% (22/263) e à rifampicina 3,8% (10/263) dos casos. A TBMR primária foi encontrada em 1,9% (4/206) dos casos e destes 25,0% (1/4) eram TBXR. A incidência média anual de TBMR foi de 0,57/100,000 habitantes. Dos 25 isolados resistentes ao menos uma droga, submetidos à RFLP, 12 (48,0%) foram agrupados em seis grupos genéticos, com dois pacientes em cada grupo. CONCLUSÕES: A elevada proporção TBMR primária, com um caso de TBXR enfatizam a necessidade de universalizar a cultura e TS, ampliar a cobertura do tratamento supervisionado, a investigação rotineira dos contatos e o monitoramento da resistência a drogas. O fortalecimento da vigilância da resistência às drogas é indispensável para o contínuo aperfeiçoamento do Programa de Controle da TB, especialmente em regiões de elevada carga da doença / INTRODUCTION: The incidence of tuberculosis (TB) in Santos (SP) is located around 73 / 100,000-year, approximately double that found on average in the country. The average prevalence of TB / HIV is 16% cure rates and treatment dropout among new cases are, respectively, 71% and 12%. Such indicators suggest high risk for multidrug-resistant TB (MR-TB) in the city, with the incidence estimated at 1.9 / 100,000-year. OBJECTIVE: To describe and analyze the sensitivity to drugs of first and second line treatment of patients with pulmonary TB (PTB) to estimate the incidence of MR-TB and extensively drugresistant TB (TBXR), describe molecular and institutional aspects, spatial distribution, epidemiological PTB resistant cases in the city of Santos (SP). METHODS: A descriptive study of a cohort of patients with PTB residing in the city who started treatment or retreatment in the period January 2011 to December 31, 2012. The case definition PTB individuals 15 years or more, both sexes, living in the city of Santos (SP), who present clinical manifestations compatible with PTB and whose confirmation was made by culture with isolation of M. tuberculosis. The variables of interest for the study were: bacteriological / laboratory socio-demographic characteristics, current and previous history of TB, aspects related to treatment, and comorbidities. For comparative analyzes of proportions the chi-squared tests and Fisher\'s exact were used for continuous variables and the Student t test or the Kruskal - Wallis. The genetic profiles of isolates resistant to at least one drug were obtained by RFLP (length polymorphism restriction fragment) and analyzed using version BioNumerics 5.0 (Applied Maths - Belgium) software. The description of the spatial distribution of resistant TB and the clusters was made by inserting the cases in Santos map, by address of residence, which was according to the index of social vulnerability. RESULTS: Of the 263 cases of PTB selected, 68.4% (180/263) were male, th median age was 38 years, 8.7% (23/263) were diabetes; 20.4% (42/206) of new cases had at least one risk factor for MR-TB, especially 10.7% (22/206) of making HIV / TB; 47.3% (123/260) underwent supervised treatment, 14.7% (91/617) of the contacts were examined, 18.6% (49/263) were hospitalized during treatment, totaling 7127 days of hospitalization with a mean 145.4 days per patient. Among the cases resistant to at least one drug resistance to isoniazid 8.4% (22/263) and rifampin 3.8% (10/263) of the cases was found. The primary MR-TB was found in 1.9% (4/206) of MR-TB cases and of these 25.0% (1/4) were TBXR. The average annual incidence of MDR-TB was 0.57/100,000 inhabitants. Of the 25 isolates resistant least one drug, subjected to molecular characterization of IS6110, 12 (48.0%) were grouped in six clusters, with each group including two isolates. CONCLUSIONS: A high proportion of primary MR-TB, including a case of TBXR emphasizes the need to universalize culture and TS, expand the coverage of supervised treatment, routine investigation of contacts and monitoring of drug resistance. The strengthening of the surveillance of drug resistance is essential for continuous improvement of the TB Control Program, especially in regions of high disease burden
33

Tuberculose multirresistente e extensivamente resistente em área metropolitana de elevada incidência - município de Santos (SP), Brasil / Multidrug and extensively drug-resistant tuberculosis in the metropolitan area of high incidence - the city of Santos (SP), Brazil

Andrea Gobetti Vieira Coelho 03 March 2015 (has links)
INTRODUÇÃO: A incidência de tuberculose (TB) em Santos (SP) situa-se em 73/100.000 habitantes-ano. A prevalência média de coinfecção TB/HIV é de 16%, taxas de cura e abandono de tratamento, entre casos novos são, respectivamente, 71% e 12%. Tais indicadores sugerem elevado risco para TB multidroga resistente (TBMR) no município, com incidência estimada em 1,9/100.000 habitantes-ano. OBJETIVO: Descrever e analisar o perfil de sensibilidade às drogas (TS) de primeira e segunda linha de tratamento entre pacientes com TB pulmonar (TBP), estimar a incidência de TBMR e a proporção de TB extensivamente resistente (TBXR); analisar aspectos moleculares, epidemiológicos e institucionais dos casos de TBP resistentes em Santos (SP). MÉTODOS: Estudo descritivo de uma coorte de pacientes de TBP, com início de tratamento ou retratamento entre 01 de janeiro de 2011 a 31 de dezembro de 2012. Definiu-se como caso de TBP, indivíduos com 15 anos ou mais, de ambos os sexos, residentes no município de Santos, com manifestações clínicas compatíveis com TBP e confirmação por cultura com isolamento de Mycobacterium tuberculosis. As variáveis de interesse para o estudo foram as características sociodemográficas, história atual e pregressa de TB, aspectos relativos ao tratamento, co-morbidades, ao diagnóstico e resistência a drogas. Para as análises comparativas entre proporções foram usados os testes qui-quadrado de Pearson e o Exato de Fisher e para variáveis contínuas o teste T de Student ou o de Kruskal - Wallis. Os perfis genéticos dos isoladas resistentes a ao menos uma droga foram obtidos pela técnica RLFP e analisados pelo programa Bionumerics versão 5.0 (Applied Maths - Bélgica). A descrição da distribuição espacial da TB resistentes e clusters foram feitas mediante a inserção dos casos no mapa de Santos, por endereço de residência, segundo o índice de vulnerabilidade social. RESULTADOS: Dos 263 casos de TBP selecionados, 68,4% (180/263) eram do sexo masculino, a mediana da idade foi de 38 anos, 8,7% (23/263) eram diabéticos; 20,4% (42/206) dos casos novos apresentavam ao menos um fator de risco para TBMR; destacando-se entre estes casos 10,7% (22/206) de confecção HIV/TB; 47,3% (123/260) tiveram tratamento supervisionado, 14,7% (91/617) dos contatos foram examinados, 18,6% (49/263) foram hospitalizados durante o tratamento, perfazendo uma média de 145,4 dias por paciente. Entre os casos resistentes a ao menos uma droga, a resistência à isoniazida foi 8,4% (22/263) e à rifampicina 3,8% (10/263) dos casos. A TBMR primária foi encontrada em 1,9% (4/206) dos casos e destes 25,0% (1/4) eram TBXR. A incidência média anual de TBMR foi de 0,57/100,000 habitantes. Dos 25 isolados resistentes ao menos uma droga, submetidos à RFLP, 12 (48,0%) foram agrupados em seis grupos genéticos, com dois pacientes em cada grupo. CONCLUSÕES: A elevada proporção TBMR primária, com um caso de TBXR enfatizam a necessidade de universalizar a cultura e TS, ampliar a cobertura do tratamento supervisionado, a investigação rotineira dos contatos e o monitoramento da resistência a drogas. O fortalecimento da vigilância da resistência às drogas é indispensável para o contínuo aperfeiçoamento do Programa de Controle da TB, especialmente em regiões de elevada carga da doença / INTRODUCTION: The incidence of tuberculosis (TB) in Santos (SP) is located around 73 / 100,000-year, approximately double that found on average in the country. The average prevalence of TB / HIV is 16% cure rates and treatment dropout among new cases are, respectively, 71% and 12%. Such indicators suggest high risk for multidrug-resistant TB (MR-TB) in the city, with the incidence estimated at 1.9 / 100,000-year. OBJECTIVE: To describe and analyze the sensitivity to drugs of first and second line treatment of patients with pulmonary TB (PTB) to estimate the incidence of MR-TB and extensively drugresistant TB (TBXR), describe molecular and institutional aspects, spatial distribution, epidemiological PTB resistant cases in the city of Santos (SP). METHODS: A descriptive study of a cohort of patients with PTB residing in the city who started treatment or retreatment in the period January 2011 to December 31, 2012. The case definition PTB individuals 15 years or more, both sexes, living in the city of Santos (SP), who present clinical manifestations compatible with PTB and whose confirmation was made by culture with isolation of M. tuberculosis. The variables of interest for the study were: bacteriological / laboratory socio-demographic characteristics, current and previous history of TB, aspects related to treatment, and comorbidities. For comparative analyzes of proportions the chi-squared tests and Fisher\'s exact were used for continuous variables and the Student t test or the Kruskal - Wallis. The genetic profiles of isolates resistant to at least one drug were obtained by RFLP (length polymorphism restriction fragment) and analyzed using version BioNumerics 5.0 (Applied Maths - Belgium) software. The description of the spatial distribution of resistant TB and the clusters was made by inserting the cases in Santos map, by address of residence, which was according to the index of social vulnerability. RESULTS: Of the 263 cases of PTB selected, 68.4% (180/263) were male, th median age was 38 years, 8.7% (23/263) were diabetes; 20.4% (42/206) of new cases had at least one risk factor for MR-TB, especially 10.7% (22/206) of making HIV / TB; 47.3% (123/260) underwent supervised treatment, 14.7% (91/617) of the contacts were examined, 18.6% (49/263) were hospitalized during treatment, totaling 7127 days of hospitalization with a mean 145.4 days per patient. Among the cases resistant to at least one drug resistance to isoniazid 8.4% (22/263) and rifampin 3.8% (10/263) of the cases was found. The primary MR-TB was found in 1.9% (4/206) of MR-TB cases and of these 25.0% (1/4) were TBXR. The average annual incidence of MDR-TB was 0.57/100,000 inhabitants. Of the 25 isolates resistant least one drug, subjected to molecular characterization of IS6110, 12 (48.0%) were grouped in six clusters, with each group including two isolates. CONCLUSIONS: A high proportion of primary MR-TB, including a case of TBXR emphasizes the need to universalize culture and TS, expand the coverage of supervised treatment, routine investigation of contacts and monitoring of drug resistance. The strengthening of the surveillance of drug resistance is essential for continuous improvement of the TB Control Program, especially in regions of high disease burden
34

The environmental monitoring and quantification of M. tuberculosis occupational exposure risk in various occupational settings in a platinum mine / H.L. Badenhorst

Badenhorst, Hendrik Louis January 2010 (has links)
Tuberculosis is a disease that has a detrimental effect on the economic growth of South Africa. The country’s TB mortality rate is amongst the highest in the world, and the worst affected industry is mining. Effective environmental controls of tuberculosis in mining areas remain a challenge, mainly because there is a lack of quantitative data to guide the implementation of these controls. No occupational exposure limits exist for bio–aerosols, particularly Mycobacterium tuberculosis. This makes it difficult to distinguish between high– and low risk areas. It is believed that a single inhaled M. tuberculosis particle can cause the tuberculosis disease, and as this disease can deteriorate all major systems of the body, great care should be taken in the classification of an area. Aim: This study aimed to quantify the environmental presence of the M. tuberculosis bacilli in various occupational settings of a platinum mine. Method: The monitored areas are all structures above ground, and include high TB risk areas, such as the hospital TB Ward, and low TB risk areas, such as an office area. Personal monitoring of the staff in high TB risk areas has also been conducted. Monitoring was done via the PTFE filter sampling method and the SKC Bio–Sampler impinger method. The results of these two methods were compared to determine which method is more effective. The environmental variables, such as carbon dioxide and -monoxide levels, temperature (both ambient and wet– bulb), and relative humidity, were also monitored in order to identify any possible correlations between these variables and the levels of ambient TB particles. The effectiveness of the Ultraviolet Germicidal Irradiation (UVGI) system, which is in place in some of the monitored areas, was also indirectly assessed, i.e. to see if there are any M. tuberculosis particles present in an area that makes use of an UVGI system. The PCR analytical method was used to quantify the number of M. tuberculosis bacilli sampled, and the results were statistically analysed. Results: M. tuberculosis was found to be present in the office area, the laundry room, the hospital’s waiting area, the training facility, the dining room, and the mobile clinic. No M. tuberculosis particles were found in the hospital’s TB Ward and the change houses of the mine. The results showed that the PTFE filter method had a greater efficiency than the SKC Bio– Sampler in monitoring environmental M. tuberculosis particles, as the PTFE filter method yielded positive samples where the SKC Bio–Sampler did not. There is a practical significant difference between the two methods. No viable correlations between the environmental variables and M. tuberculosis prevalence were established due to the low number of samples taken. Conclusion: It seems that the effectiveness of a UVGI system is dependent on the number of people crowded into that specific area and the ventilation thereof. A UVGI system is only a precautionary measure and not a solution. There are too many factors that still need better understanding before the risk of contracting environmental TB in high risk areas of a mine can be determined. The high risk areas seem to be occupational settings that have poor ventilation, but accommodate a large number of people. The highest risk of TB infection remains close contact with infected individuals, as the results of the employee monitoring testified. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.
35

The environmental monitoring and quantification of M. tuberculosis occupational exposure risk in various occupational settings in a platinum mine / H.L. Badenhorst

Badenhorst, Hendrik Louis January 2010 (has links)
Tuberculosis is a disease that has a detrimental effect on the economic growth of South Africa. The country’s TB mortality rate is amongst the highest in the world, and the worst affected industry is mining. Effective environmental controls of tuberculosis in mining areas remain a challenge, mainly because there is a lack of quantitative data to guide the implementation of these controls. No occupational exposure limits exist for bio–aerosols, particularly Mycobacterium tuberculosis. This makes it difficult to distinguish between high– and low risk areas. It is believed that a single inhaled M. tuberculosis particle can cause the tuberculosis disease, and as this disease can deteriorate all major systems of the body, great care should be taken in the classification of an area. Aim: This study aimed to quantify the environmental presence of the M. tuberculosis bacilli in various occupational settings of a platinum mine. Method: The monitored areas are all structures above ground, and include high TB risk areas, such as the hospital TB Ward, and low TB risk areas, such as an office area. Personal monitoring of the staff in high TB risk areas has also been conducted. Monitoring was done via the PTFE filter sampling method and the SKC Bio–Sampler impinger method. The results of these two methods were compared to determine which method is more effective. The environmental variables, such as carbon dioxide and -monoxide levels, temperature (both ambient and wet– bulb), and relative humidity, were also monitored in order to identify any possible correlations between these variables and the levels of ambient TB particles. The effectiveness of the Ultraviolet Germicidal Irradiation (UVGI) system, which is in place in some of the monitored areas, was also indirectly assessed, i.e. to see if there are any M. tuberculosis particles present in an area that makes use of an UVGI system. The PCR analytical method was used to quantify the number of M. tuberculosis bacilli sampled, and the results were statistically analysed. Results: M. tuberculosis was found to be present in the office area, the laundry room, the hospital’s waiting area, the training facility, the dining room, and the mobile clinic. No M. tuberculosis particles were found in the hospital’s TB Ward and the change houses of the mine. The results showed that the PTFE filter method had a greater efficiency than the SKC Bio– Sampler in monitoring environmental M. tuberculosis particles, as the PTFE filter method yielded positive samples where the SKC Bio–Sampler did not. There is a practical significant difference between the two methods. No viable correlations between the environmental variables and M. tuberculosis prevalence were established due to the low number of samples taken. Conclusion: It seems that the effectiveness of a UVGI system is dependent on the number of people crowded into that specific area and the ventilation thereof. A UVGI system is only a precautionary measure and not a solution. There are too many factors that still need better understanding before the risk of contracting environmental TB in high risk areas of a mine can be determined. The high risk areas seem to be occupational settings that have poor ventilation, but accommodate a large number of people. The highest risk of TB infection remains close contact with infected individuals, as the results of the employee monitoring testified. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.
36

The burden of hearing loss amongst multi-drug resistant-tuberculosis patients on Bedaquiline at Zithulele Hospital, Eastern Cape Province.

Matikinca, Sibulele January 2022 (has links)
Thesis ( MPH.) -- University of Limpopo, 2022 / Background Multidrug-resistant tuberculosis (MDR-TB) has recently resulted to be in an emergence state globally and this of constitute a big challenge for TB control and the goals of the World Health Organization’s End TB Strategy. Aminoglycosides (AG) were often used as part of treatment of life-threatening illnesses such as MDR-TB for decades, however their adverse effects are widely described and hearing loss is one of the major side effects. The risk factors for hearing loss in patients treated with AG include the dose and duration of AG, infection with human immunodeficiency virus (HIV), older age and persons exposed to a high level of noise while the damage can be total and permanent. Severe hearing impairment has been reported to occur among patients treated for MDR-TB with injectable drugs, especially among the elderly and patients infected with human immunodeficiency virus, however, Bedaquiline containing regimens have demonstrated improved outcomes over injectable containing regimens in the long-term treatment of MDR-TB. Methods The objective of the current study was to investigate the burden of hearing loss amongst MDR-TB patients on bedaquiline at Zithulele Hospital in Eastern Cape Province. Therefore, the current study followed a quantitative retrospective approach using simple random sampling to select MDR-TB patients treated with bedaquiline and having a baseline audiogram be the initiation of treatment. The data was captured in a Microsoft Excel spreadsheet and then transferred to Statistical Package for Social Sciences (SPSS) Version 20 for data analysis in which categorical variables were presented as percentages and frequencies, while continuous variables was presented as mean, median and standard deviation lastly, comparison of categorical variables was done using a Chi-Squared test, whereas continuous variables were compared using a t-test. P-value of <0.05 will be considered significant. Results The mean age for the participants was 39.2 years with standard deviation of 11.8 and there was no statistical significance difference between the age groups (p value = 0.178). There no was a statistical significance difference between the employment status (p value = 0.794), previous use of injectables (p value = 0.360) and type of hearing of loss (p value = 0.536). Majority of the MDR-TB patients on bedaquiline did not have hearing loss at 67% while those who had gradual hearing loss and sudden hearing loss were 26.8% and 6.2% respectively. There was no statistical significance difference between males and females in both the right and left ears, however, the right ear results appeared to be slightly worse than the left ear results. It was found that both males and females had a high frequency hearing loss in the left ears of 26.8% and 22.2% respectively as compared to the right ears with of 25.9% and 1.6% respectively. The was a statistical significance difference between the age groups in both ears for hearing loss at p-value <0.001. The overall prevalence of hearing loss was found to be 32.9% and hearing loss at 20dB or more loss at any frequency was low at 11.9% while hearing loss at 10B or more loss at any frequency was the highest at 32.9% followed by loss response at 3 consecutive frequencies at 26.2%. Hearing loss was increasing with increasing age from 8.3% in age group and age was significantly associated with hearing loss as older patients were 2.2 times more likely to have a hearing loss at a degree of 20dB and 4.4 times more likely to have a hearing loss at a degree of 10dB. Previous use of injectables was also significantly associated with hearing loss as patients who used injectables previously were 11.5 times more likely to have a hearing loss at degree of 10dB, 5.6 and 11.3 times more likely to have a hearing loss at loss response at 3 consecutive frequencies and overall hearing loss respectively. Conclusion South Africa has a high burden of drug-resistant tuberculosis (DRTB) and until recently, ototoxic aminoglycosides were predominant in treatment regimens. Drug resistant TB treatment with bedaquilines caused clinically and statistically significant deterioration of hearing loss in patients, most prominently at high frequencies. Although public health interventions to prevent hearing loss have been deemed cost effective and have meaningful individual and economic implications, hearing loss and its prevention consistently receive inadequate attention as a global public health priority. Despite the serious impacts of hearing loss, little is known regarding prevalence of ototoxic hearing loss after treatment for DR-TB. Therefore, when the use of injectable ototoxic medications is unavoidable, audiological ototoxicity monitoring is essential to optimise hearing-related outcomes.
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Adesão ao tratamento para tuberculose multirresistente: estudo de caso em uma unidade ambulatorial de referência terciária em Niterói/RJ

Costa, Patricia Valéria January 2015 (has links)
Submitted by Ana Lúcia Torres (bfmhuap@gmail.com) on 2017-10-09T16:06:50Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Patricia Costa.pdf: 1100032 bytes, checksum: eb4ab925fc60980c9f75450c5ed034b7 (MD5) / Approved for entry into archive by Ana Lúcia Torres (bfmhuap@gmail.com) on 2017-10-10T11:33:15Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Patricia Costa.pdf: 1100032 bytes, checksum: eb4ab925fc60980c9f75450c5ed034b7 (MD5) / Made available in DSpace on 2017-10-10T11:33:15Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação Patricia Costa.pdf: 1100032 bytes, checksum: eb4ab925fc60980c9f75450c5ed034b7 (MD5) Previous issue date: 2015 / Instituto Estadual de Doenças do Tórax Ary Pareiras / Adesão ao tratamento e o consequente aumento das taxas de cura resultam da interação de fatores relacionados aos serviços de saúde, aos pacientes, à sociedade e à gestão pública. Foi realizado um estudo de caso em uma unidade ambulatorial de referência terciária (UART) para o tratamento da TBMDR no município de Niterói/RJ, utilizando a abordagem quantitativa e qualitativa com o objetivo de conhecer os fatores relacionados à adesão, na perspectiva dos usuários, profissionais e gestores. Foram utilizadas diferentes fontes de evidência na busca de pontos comuns e divergentes e a análise de conteúdo possibilitou a identificação de fatores favoráveis ou não à adesão a partir das categorias adesão, acesso, acolhimento, vínculo, responsabilização. A maioria dos pacientes em tratamento relatou dificuldade de acesso aos benefícios sociais. A ausência de alguns profissionais na equipe comprometeu a abordagem de importantes questões relativas ao perfil dos pacientes, principalmente a vulnerabilidade social, o consumo de álcool e de outras drogas, além do isolamento e preconceito. A oferta gratuita de mediação, a realização de exames na própria UART, a flexibilidade nos agendamentos, a busca de faltosos e o vínculo com a equipe de saúde foram descritos como fatores importantes para a adesão. O conhecimento sobre a doença atual e seu tratamento e seu tratamento associados à vontade do paciente de curar-se foram relatados como aspectos importantes para superar as barreiras encontradas para a realização do tratamento. Os resultados apresentados sugerem que, apesar da existência de fatores desfavoráveis à adesão, as ações de acolhimento, vínculo e responsabilização desenvolvidas pelo serviço foram suficientes para promover a adesão no grupo estudado. Entretanto, recomenda-se a melhoria do acesso aos benefícios assistenciais, a implementação de novas formas de comunicação sobre as formas graves de tuberculose e a articulação com outros segmentos públicos e da sociedade para o enfrentamento da TBMDR
38

Investigation of the genetic aetiology of aminoglycoside-induced hearing loss in South African populations

Human, Hannique 12 1900 (has links)
Thesis (MScMedSc (Biomedical Sciences. Molecular Biology and Human Genetics))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: South Africa is currently facing a major multidrug-resistant tuberculosis (MDR-TB) epidemic and has one of the highest incidences in the world. Aminoglycoside antibiotics are commonly used in this country as a treatment against MDR-TB. A well known side-effect of aminoglycosides is permanent hearing loss and this is thought to have a significant genetic component. To date, at least six mutations in the mitochondrial genome are known to confer susceptibility to aminoglycosideinduced hearing loss. It is imperative that we investigate the frequency of these mutations in our populations and determine whether certain sub-groups are at increased risk. The aim of the present study was therefore to investigate the genetic aetiology of aminoglycoside-induced hearing loss in the South African population. A multiplex method using the ABI Prism® SNaPshotTM Multiplex system was optimised to screen for six mutations in the MT-RNR1: A1555G, C1494T, T1095C, 961delT+C(n), A827G and T1291C. A total of 115 MDR-TB patients from the Brooklyn Chest Hospital in Cape Town who were receiving high doses of either streptomycin, kanamycin or capreomycin were recruited for this study. Furthermore, 439 control samples, comprising of 93 Afrikaner, 104 Caucasian, 112 Black and 130 Mixed Ancestry individuals were recruited and screened for the presence of the six mutations. Identification of novel variants in the MT-RNR1 and the entire mitochondrial genome was performed using High Resolution Melt analysis (HRM) and whole mitochondrial DNA sequencing, respectively. A total of 97 family members from a South African family known to harbour the A1555G mutation were recruited and genotyped using SNaPshot analysis. In addition, mitochondrial functioning in the presence of different streptomycin drug concentrations, in transformed lymphoblasts of an individual harbouring the A1555G, was assessed by means of the MTT colorimetric assay. Detection of heteroplasmic mutations was performed using PCRRestriction Fragment Length Polymorphism (RFLP) analysis and UN-SCAN-IT software. We successfully developed a robust and cost-effective method that detects the presence of all six mutations simultaneously. The method worked equally well on both blood (from adults) and buccal swabs (from children). The C1494T, T1095C and T1291C mutations were not detected in any of the MDR-TB or control groups. Alarmingly, the A1555G mutation was detected in 0.9% of the Black control samples and in 1.1% of the Afrikaner controls (in one sample in the heteroplasmic state 25%). The A827G mutation was present at a frequency of 0.9% in the MDR-TB patients and in 1.1% of the Afrikaner controls. The 961delT + insC(n) mutation was found in relatively high frequencies in both the MDR-TB patients (3.5%) and control groups (1.1% of the Afrikaner, 1.5% of the Mixed Ancestry and 7.1% of the Black samples). Similarly, the T961G mutation was III detected at high frequencies in the Caucasian (2.9%) and Afrikaner (3.2%) controls. Screening for novel variants in MT-RNR1 in MDR-TB patients experiencing ototoxicity revealed two novel variants (G719A and T1040C). However, G719A and T1040C are not likely to be pathogenic since they were detected in ethnic-matched controls: Mixed Ancestry (20.7%) and Black (1.8%) controls. Furthermore, a total of 50 novel variants were identified within the mitochondrial genome of eight MDR-TB patients with ototoxicity. Only five of the 50 variants (one in the MT-TH, ND3, COX3 and two in the CYTB gene) were shown to reside at positions that are evolutionarily conserved across five species from human to frog, and the four variants in the protein coding genes resulted in missense changes. A total of 76 of the 97 family members recruited were found to be A1555Gpositive (on mitochondrial haplogroup L0d) and are therefore at risk of developing irreversible hearing loss. Genes and variants known to act as genetic modifiers: tRNASer(UCN), homozygous A10S in TRMU and 35delG in GJB2 were not present in this family. For the MTT assay, decreased mitochondrial functioning of cells harbouring the A1555G mutation in the presence of streptomycin were (compared to wild type) observed but this was not statistically significant (p-value: 0.615- 0.999). The high frequency of the A1555G mutation (0.9%) in the Black population in South Africa is of concern given the high incidence of MDR-TB in this particular ethnic group. However, future studies with larger numbers of samples are warranted to determine the true frequencies of the aminoglycoside deafness mutations in the general South African population. Our data suggests that the 961delT + insC(n) and T961G variants are common non-pathogenic polymorphisms due to the high frequencies observed in controls (>1%). The identification of the first novel variants within protein coding genes that could possibly be associated with aminoglycoside-induced hearing loss holds great possibilities with regards to the identification of a second gene involved in drug induced hearing loss. Future studies where the possible effect of these variants on the normal functioning of these genes could be assessed would contribute greatly to this field of research. All 76 A1555Gpositive members of the family were given genetic reports and counseled about their risk and that of their children for developing hearing loss due to aminoglycoside use. The development of a rapid and cost-effective genetic method facilitates the identification of individuals at high risk of developing hearing loss prior to the start of aminoglycoside therapy. This is of critical important in a low-resource country like South Africa where, despite their adverse sideeffects, aminoglycosides will be continue to be used routinely and are accompanied with very limited or no audiological monitoring. Future studies and greater public awareness is therefore needed to address this serious problem. / AFRIKAANSE OPSOMMING: Suid Afrika beleef tans „n grootskaalse tuberculose epidemie (veral weerstandige vorme van tuberculose) (MDR-TB), met een van die hoogste voorkomssyfers in die wêreld. Aminoglikosied antibiotikums word baie algemeen gebruik in Suid Afrika vir die behandeling van MDR-TB. ‟n Bekende newe effek van die middels is permanente gehoor verlies en dit is van mening dat dit gekoppel is aan „n genetiese component. Daar is tans ses mutasies in die mitochondriale genoom wat vatbaarheid tot aminoglikosied-geinduseerde gehoor verlies veroorsaak. Daarom is dit van uiterse belang dat die frekwensie van die mutasies in ons populasies bepaal word sodat daar vasgestel kan word watter groepe „n hoë risiko het om gehoor verlies te kan ontwikkel. Die ABI Prism® SNaPshotTM Multipleks sisteem is gebruik en geoptimiseer om te toets vir die ses mutasies in die MT-RNR1: C1494T, T1095C, 961delT+C(n), A827G and T1291C. „n Totaal van 115 MDR-TB pasiente van die Brooklyn Chest Hospital in Kaap Stad is gewerf vir die studie. Hierdie pasiente ontvang daaglikse hoë dosese van een van die volgende aminoglikosiede: streptomycin, kanamycin of capreomycin. Verder is „n totaal van 439 kontrole DNA monsters gewerf vanuit die volgende etniese groepe: 93 Afrikaner, 104 Blank, 112 Swart and 130 Kleurling. Hierdie monsters is ook getoets vir die ses mutatsies. Hoë Resolusie Smelt analise (HRS) is gebruik om nuwe DNS volgorde veranderinge in die MT-RNR geen te identifiseer. Die hele mitochondriale genoom is blootgestel aan DNA volgorde bepaling in „n poging om nuwe DNS volgorde verandering in die genoom te identifiseer wat moontlik betrokke kan wees by aminoglikosied-geinduseerde gehoor verlies. „n Total van 97 lede van „n Suid Afrikaanse familie waar die A1555G mutasie teenwoordig is, is deur middle van die SNaPshot metode gegenotipeer. Verder is die normale funcitoneering van die mitochondrion in getransformeerde witbloed selle, getoets in die teenwoordigheid van verskillende konsentrasies streptomycin met behulp van die MTT kleurmetrie toets. Deteksie van heteroplasmiese mutasies is gedoen deur middle van die PCR-RFLP tegniek en alle analises is gedoen op die UN-SCAN-IT program. Ons was suksesvol in die ontwikkeling van „n vinnige, koste effektiewe en kragtige tegniek wat al ses die mutasies in MT-RNR1 in een reaksie kan optel. Hierdie tegniek het goed gewerk met DNA monsters van bloed en van selle verkry vanuit die wangholte (geneem van kinders jonger as 12 jaar). Die C1494T, T1095C en T1291C mutasies is glad nie waargeneem in enige van ons MDR-TB patiente of kontroles nie. Skrikwekkend is die hoë frekwensie (0.9%) waarby die A1555G mutasie in die Swart kontrole groep waargeneem is. Hierdie mutasie is ook in 1.1% van die Afrikaner kontrole groep opgemerk in heteroplasmie van 25%. Die A827G mutasie was teenwoordig in 0.9% en 1.1% van die MDR-TB patiente en Afrikaner kontrole monsters, onerskeidelik. Die 961delT + insC(n) mutasie is opgemerk in baie hoë frekwensies in beide die MDR-TB (3.5%) en kontrole groepe (1.1% van die Afrikaner, 1.5% van die Kleurling en 7.1% van die Swart monsters). Die T961G mutasie is ook in hoë frekwensies in slegs die Blanke (2.9%) en die Afrikaner (3.2%) kontrole groepe waargeneem. Nuwe DNS volgorde veranderinge in MT-RNR1 is gesoek in „n groep MDR-TB patiente wat gehoor verlies ondervind. Slegs twee nuwe verandering is ontdek (G719A en T1040C). Dit is onwaarskynlik dat hierdie veranderinge patogenies is siende dat hulle teen frekwensies van 20.7% en 1.8% waargeneem is in die Kleurling en Swart kontrole groepe onderskeidelik. Tydens die soeke na nuwe DNS volgorde veranderinge wat moontlik geassosieer is met aminoglikosied-geinduseerde gehoor verlies in die mitochondriale genoom is 50 onbekende veranderinge ontdek (een in die MT-TH, ND3, COX3 en twee in die CYTB gene). Die veranderinge is verder ondersoek vir evolusionêre konservasie op beide die nukliotied en amino suur vlak van mens to padda. Dit is bevind dat 76 uit die 97 familie lede positief is vir die A1555G mutasie en het dus „n hoë risiko om aminoglikosied-geinduseerde gehoor verlies te ontwikkel as hul bloot gestel word aan hierdie antibiotikums. Verder is gevind dat hierdie familie op die L0d mitochondriale haplogroep lê. Geen van die sogenaamde genetiese modifiseerde gene of DNS volgorde veranderinge in hierdie gene (tRNASer(UCN), A10S in TRMU in homosigotiese vorm en die 35delG in GJB2) is gevind in die familie nie. Die MTT toets het „n afname in die mitochondriale funksioneering van selle waar die A1555G mutasie teenwoordig was getoon, alhoewel die verskil tussen selle wat nie die A1555G mutasie het nie, nie statisties betekenisvol was nie (p-waarde: 0.615-0.999). Die hoë frekwensie van die A1555G mutasie (0.9%) in die Swart populasie van Suid Afrika is skrikwekkend siende dat die voorkomssyfer van MDR-TB in hierdie groep baie hoog is. Toekomstige studies met grooter getalle is nodig om die ware frekwensie van die mutasies geassosieer met aminoglikosied-geinduseerde gehoor verlies in die algemende Suid Afrikaanse populasie te bepaal. Ons data dui aan dat die 961delT + insC(n) en die T961G mutasies slegs algemene nie-patogeniese polimorphismis is siende dat dit in sulke hoë frekwensies (>1%) in kontroles opgemerk is. Die identifiseering van die eerste DNS volgorde veranderinge in proteïen kodeerende gene wat moontlik geassosieer is met aminoglikosied-geinduseerde gehoor verlies hou groot en belowende moontlikehede in, interme van die identifiseering van „n tweede geen. Toekomstige studies waarin die effek van hierdie veranderinge op die normale funktioneering van hierdie gene ondersoek word sal „n besondere groot bydrae lewer tot hierdie veld van navorsing. Al 76 van die A1555G positiewe familie lede is voorsien van genetiese verslae en het berading ontvang in verband met hul risiko en die risiko van hul kinders om aminoglikosied-geinduseerde gehoor verlies te ontwikkel. Die ontwikkeling van „n kragtige, vinnige en koste-effektiewe genetiese metode vergemaklik die vinnige identifiseering van hoë risiko individue vir die ontwikkeling van gehoor verlies voordat hulle met hul aminoglikosiede behandeling begin. Dit is veral noodsaaklik in „n derde wêreld land soos Suid Afrika waar, ten spyte van hul gevaarlike newe effekte, aminoglikosied antibiotikums steeds gebruik sal word. Daarom is grooter publieke bewusmaking nodig om hierdie problem te probeer oplos en te verhoed.
39

Regulation of efflux in rifampicin resistant mutants of Mycobacterium tuberculosis

Willemse, Danicke 03 1900 (has links)
Thesis (MScMedSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Multidrug resistant tuberculosis (MDR-TB), defined as having resistance to at least the first-line drugs, isoniazid and rifampicin (RIF), is a global health problem. Mutations in the rpoB gene, encoding the β-subunit of RNA polymerase, are implicated in RIF resistance - with the S531L and H526Y mutations occurring most frequently. The level of RIF resistance varies for strains with identical rpoB mutations, which suggests that other factors play a role in RIF resistance. Efflux has been implicated in determining the intrinsic level of RIF resistance. Increased expression of the multidrug efflux pump, Rv1258c, following RIF exposure was observed in some Mycobacterium tuberculosis MDR clinical isolates and H37Rv RIF mono-resistant mutants, but not others. The factors influencing the induction of Rv1258c are poorly understood. The aim of this study was to investigate the effects of rpoB mutations on expression of Rv1258c and whiB7, a transcriptional regulator of Rv1258c, in M. tuberculosis H37Rv in vitro generated RIF resistant mutants, in the absence and presence of RIF. The promoter region of M. tuberculosis H37Rv Rv1258c was cloned into a position upstream of a lacZ gene (encoding β-galactosidase) in multi-copy episomal and integrating vectors. Vector functioning and the effect of rpoB mutations on Rv1258c promoter activity were initially investigated in the non-pathogenic related species, Mycobacterium smegmatis mc2155 rpoB mutants and subsequently in M. tuberculosis by doing β-galactosidase assays. qRT-PCR was done to investigate the effects of rpoB mutations on native Rv1258c and whiB7 gene expression. Episomal and integrating vectors were functional and the integrating vector system was used for subsequent β-galactosidase assays in M. tuberculosis. Rv1258c promoter activity in the S531L mutant was approximately 1.5 times less and in the H526Y mutant 1.5 times higher than that of the wild-type in M. smegmatis. Similarly, Rv1258c promoter activity in the S531L mutant was approximately half and in the H526Y mutant approximately double that of the wild-type in M. tuberculosis. A similar trend in Rv1258c and whiB7 expression to those observed using β-galactosidase assays were observed when investigating the native Rv1258c and whiB7 gene transcript levels compared to the wild-type using qRT-PCR, although differences were not significant. Exposure of the M. smegmatis and M. tuberculosis rpoB mutants to sub-inhibitory levels of RIF did not affect Rv1258c promoter activity. Mutations in rpoB had a marginal effect on Rv1258c and whiB7 transcript levels, but showed the same trend as that seen for Rv1258c promoter activity. It remains to be determined whether these differences are biologically significant. When considering efflux pumps as new targets for treatment, possible differences in efflux pumps expression due to different rpoB mutations should be considered. / AFRIKAANSE OPSOMMING: Multi-middel weerstandige tuberkulose (MDR-TB) word gedefinieer as weerstandigheid tot ten minste rifampisien (RIF) en isoniasied, wat deel van die eerstelyn anti-tuberkulose behandeling vorm. Mutasies in die rpoB geen, wat die β-subeenheid van die RNA polimerase enkodeer, word geassosieer met RIF weerstandigheid. S531L en H526Y rpoB mutasies kom die algemeenste voor. RIF weerstandigheids vlakke verskil egter tussen isolate met identiese rpoB mutasies, wat impliseer dat ander faktore ook 'n rol in RIF weerstandigheid speel. 'n Toename in transkripsie van die Rv1258c geen, wat 'n multi-middel effluks pomp enkodeer, is waargeneem met blootstelling aan RIF, slegs in sommige M. tuberculosis H37Rv RIF mono-weerstandige mutante and MDR kliniese isolate, maar nie in ander nie. Die faktore wat die induksie van die Rv1258c effluks pomp beïnvloed is nie goed nagevors nie. Die studie ondersoek die effek van die rpoB mutasies op die uitdrukking van die Rv1258c en whiB7,'n transkripsionele regulator van Rv1258c, gene in M. tuberculosis H37Rv in vitro gegenereerde RIF weerstandige mutante, in die teenwoordigheid en afwesigheid van RIF. Die promotor area van die M. tuberculosis H37Rv Rv1258c geen is in 'n posisie stroomop van 'n lacZ geen, wat vir β-galaktosidase enkodeer, in multi-kopie episomale en integreerende vektors ingekloneer. Die funksionaliteit van die vektor en effek van rpoB mutasies op Rv1258c promotor aktiwiteit is ondersoek in die naverwante nie-patogeniese spesies, M. smegmatis en daarna in M. tuberculosis deur β-galaktosidase essais te doen. qRT-PCR is gedoen om die effek van rpoB mutasies op die vlak van transkripsie van die natuurlike Rv1258c geen en die whiB7 geen te bestudeer. Beide die episomale en integreerende vektors was funksioneel en daar is besluit om die integreerende vektor vir daaropeenvolgende β-galaktosidase essais in M. tuberculosis te gebruik. Rv1258c promotor aktiwiteit van die S531L mutant was ongeveer 1.5 keer minder as en die van die H526Y mutant 1.5 keer hoër as die van die ongemuteerde bakterië in M. smegmatis. Soortgelyk was die Rv1258c promoter aktiwiteit van die S531L mutant ongeveer die helfde van en die van H526Y mutant ongeveer dubbel die van die ongemuteerde bakterië in M. tuberculosis 'n Soortgelyke neiging in die vlakke van Rv1258c en whiB7 transkripte van die natuurlike geen is gedurende qRT-PCR waargeneem alhoewel die verskille nie beduidend was nie. Blootstelling aan sub-inhibitoriese konsentrasies van RIF het geen effek op Rv1258c uitdrukking in die M. smegmatis of M. tuberculosis rpoB mutante gehad nie. Die rpoB mutasies het net 'n effense effek op Rv1258c en whiB7 transkrip vlakke in M. tuberculosis rpoB mutante, maar transkrip vlakke het 'n soortgelyke neiging as die Rv1258c promoter aktiwiteit getoon. Of die waargenome verskille biologies betekenisvol is, moet nog bepaal word. Indien effluks pompe as teikens vir bahandeling gebruik sou word, moet in ag geneem word dat effluks pompe moontlik verskillend uitgedruk word in verskillende rpoB mutante. / The DST/NRF Centre of Excellence in Biomedical Tuberculosis Research, Stellenbosch University / DAAD-NRF in Country Scholarship and Ernst and Ethel Eriksen Trust / Harry Crossley Foundation
40

Diagnostic utility of the line probe assay for the detection of drug resistance in Mycobacterium tuberculosis

Barnard, Marinus 03 1900 (has links)
Thesis(PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The epidemic levels of drug-resistant tuberculosis (DR-TB) in high-burden countries such as South Africa, which is currently ranked as third highest in the world, is the result of a synergistic relationship between the increased transmission of DR strains, poor patient adherence as well as Human-Immunodeficiency Virus (HIV)-coinfection. The impact of these combined factors on the rise of DR-TB led to an urgent need for the development of new diagnostic tools to rapidly detect TB and its associated drug susceptibility profile. The Foundation for Innovative New Diagnostics (FIND) has taken the onus upon them to ensure that laboratory strengthening becomes a reality by having developed, and still developing, new diagnostic assays in order to improve the laboratory turn-around time (TAT), whereby the transmission of DR-TB strains can be stopped. Laboratory strengthening does not solely rely on new diagnostic assays alone, and thus a Quality Management System, discussed in the dissertation, must be in place to ensure that the rapid result is accurate and reliable. The series of studies encompassed in this dissertation includes methodological validations (both technical and operational) of rapid TB diagnostic assays in order to rapidly and accurately diagnose the disease, and thus reducing the diagnostic delay associated with conventional diagnostic platforms. The studies were conducted “in-house” at the National Health Laboratory Service (NHLS) Reference TB laboratory in Green Point, Cape Town, which is a high-volume public health laboratory. The need to rapidly detect resistance to the first line anti-tubercular drugs Isoniazid and Rifampicin was a priority and thus the performance of a commercial line probe assay (LPA), the GenoType®MTBDRplus Ver1.0 LPA, was assessed for use on smear positive direct patient material. The performance characteristics was superior to that of conventional drug susceptibility testing, where the sensitivity and specificity for the detection of multi-drug resistant TB (MDR-TB) was 98.8 and 100%, respectively, with results in 1-2 days. Based on this study, the World Health Organization (WHO) endorsed the use of molecular LPA for the rapid detection of DR-TB. Furthermore, the need for quality assurance associated with the GenoType®MTBDRplus LPA in the diagnostic laboratory is essential and thus a user manual for the molecular detection of Drug Resistant Tuberculosis in resource-limited settings has also been developed (http://www.finddiagnostics.org/export/sites/default/resource-center/reports brochures/docs/LPA LaboratoryManual22Mar2012.pdf) for which Global Laboratory Initiative (GLI) status is pending. With the outbreak of extensively drug resistant TB (XDR-TB) in Tugela Ferry area in KwaZulu-Natal and the rest of the world, the need to rapidly detect resistance to the second line drugs arose, and thus the performance characteristics of the GenoType®MTBDRsl LPA was assessed for use on smear positive direct patient material. The performance characteristics proved to be excellent once again, with a 93.3% reduction in TAT. The data was scrutinized by the WHO, where it may be used as a triage test to guide treatment, but to date, no final policies on the use thereof has been finalized. The need for rapid point-of-care (POC) testing led to the implementation of the Xpert®MTB/RIF assay in the referral laboratories, for use on both smear positive and smear negative direct patient material. In order to accommodate for laboratories where the LPA has been implemented already, the GenoType®MTBDRplus Ver2.0 LPA was developed, which is aimed for use on all smear types as well. A head-to-head assessment was done between these assays to determine their performance characteristics and it was shown to be equally good. In this study we have shown the utility of molecular diagnostic assays to rapidly diagnose TB and its associated drug susceptibility patterns. This will have a significant impact on diagnostic delay and clinical decision making as well as patient outcome. / AFRIKAANSE OPSOMMING: Die epidemiese vlakke van middel-weerstandige tuberkulose (MW-TB) in hoë-lading lande, soos Suid Afrika wat tans derde hoogste op die wêreld ranglys is, is die nagevolge van 'n sinergistiese verband tussen die verhoogde voorkoms van transmissie van MW stamme, swak pasiënt deelname aan die voorgeskrewe behandelings programme, asook Menslike Immuniteitsgebreksvirus (MIV) ko-infeksie. Die impak van hierdie drie faktore saam, gee aanleiding tot 'n verhoging in MW-TB en dus was daar 'n daadwerklike behoefte vir die ontwikkeling van nuwe diagnostiese toetse wat nie net TB kan identifiseer nie, maar wat ook die gepaardgaande middel-weerstandigheids profiel aandui. Die “Foundation for Innovative New Diagnostics” (FIND) het die onus van laboratorium versterking op hulself geneem, deur te verseker dat die nuut ontwikkelde diagnostiese toetse, asooks steeds ontwikkelende diagnostiese toetse, gebruik kan word om die konsep van laboratorium versterking 'n realiteit te maak. Die doel is dus om sodoende die tyd-tot-resultaat tussen geneesheer en laboratorium te verbeter, terwyl die transmissie van MW-TB ook die hok geslaan kan word. Nietemin, laboratorium versterking berus nie net op nuwe diagnostiese toetse nie, en dus is dit noodsaaklik dat 'n Kwaliteitbestuursisteem, soos bespreek in hierdie verhandeling, in plek is om te verseker dat die resultaat spoedig, akkuraat en betroubaar is. Die samevattende reeks studies in hierdie verhandeling behels metodologiese validasies (beide tegnies en operasioneel van aard) van spoedige TB diagnostiese toetse met die doel om die siekte so vinnig en akkuraat as moontlik te diagnoseer en dus die diagnostiese vertraging, wat histories met konvensionele metodes geassosiëerd is, te verminder. Al die studies is uitgevoer in die “National Health Laboratory Service (NHLS)” TB verwysingslaboratorium in Groenpunt, Kaapstad, wat 'n hoë-volume publieke gesondheidslaboratorium is. Die noodsaaklikheid om weerstandigheid teenoor die eerste-linie antituberkulose middels isoniasied en rifampisien so spoedig moontlik te diagnoseer het 'n groot bekommernis geword, en dus is die laboratorium daartoe genoop om die prestasie eienskappe van 'n kommersiëel beskikbare “line probe assay” (LPA), die “Genotype®MTBDRplus Ver1.0 LPA”, te asseseer vir die gebruik daarvan op direkte pasientmateriaal wat smeer positief is. Die prestasie eienskappe was beter as die van konvensionele middelvatbaarheidstoetse, waar die sensitiwiteit en spesifisiteit vir die diagnosering van MW-TB 98.8 en 100%, respektiewelik, was. Verder was die resultate ook binne 1-2 dae beskikbaar. Op grond van dié bevindinge het die Wêreldgesondheidsorganisasie (WGO) die gebruik van hierdie molekulêre “LPA” vir die spoedige diagnose van MW-TB onderskryf. Nietemin, die belangrikheid van gehalteversekering wat met die “GenoType®MTBDRplus LPA” in die diagnostiese laboratorium geassosieerd is, is essentiëel en dus is 'n gebruikershandleiding vir die molekulêre diagnose van MW-TB in beperkte hulpbron-instellings ontwikkel (http://www.finddiagnostics.org/export/sites/default/resource-center/reports brochures/docs/LPA LaboratoryManual22Mar2012.pdf) waarvoor daar op„n “Global Laboratory Initiative (GLI)” status in afwagting is. Met die uitbraak van ekstensiewemiddelweerstandige TB (EMW-TB) in die Tugela Ferry distrik in KwaZulu-Natal asook in die res van die wêreld, het die noodsaaklikheid onstaan om weerstandigheid teenoor die tweede-linie middels ook so spoedig moontlik te diagnoseer, en die laboratorium is dus weereens daartoe genoop om die prestasie eienskappe van die “GenoType®MTBDRsl LPA” (ook vir die gebruik op direkte pasient materiaal wat smeer positief is) te asseseer. Die prestasie eienskappe was weereens verbysterend, en het „n 93.3% afname in tyd-tot-resultaat getoon. Die data is deur die WGO aangevra, en daar is besluit dat die toets gebruik kan word om behandeling in werking te stel, maar geen finale onderskrywings is tot op hede nog gemaak nie. Die behoefte aan 'n punt-van-sorg toets het gelei tot die implementering van die “Xpert®MTB/RIF” toets in die verwysingslaboratorium, en is geoogmerk vir die gebruik op beide smeer positiewe en -negatiewe direkte pasient materiaal. Omrede die “LPA” al in verskeie laborotoriums geimplementeer was, is die “GenoType®MTBDRplus Ver2.0 LPA” ontwikkel, waarvan die gebruik onafhanklik is van die smeerresultaat. 'n Direkte assesering tussen die twee toetse was gedoen en daar is bevind dat beide se prestasie eienskappe vergelykend was. In hierdie studies het ons bewys dat die gebruik van molekulêre diagnostiese toetse in staat is om TB en die gepaargaande middel-weerstandigheids profiel spoedig te diagnoseer. Hierdie bevindinge sal 'n groot impak hê op die vetraging van tyd-tot-resultaat, op die mediese besluitneming asook op die uitkoms van die pasiënt. / FIND (Foundation for Innovative New Diagnostics) / Hain Lifescience / National Health Laboratory Service (NHLS)

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