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

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.

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.

No description available.

Migrant workers in the Deciduous Fruit Industry are part of the marginalised communities in South Africa. They are often voiceless in the communities they find themselves. They are historically displaced, often prone to xenophobia and very vulnerable in terms of HIV. Not only do they have a high infection rate but they also struggle in isolation to carry the burden of HIV and AIDS affection or infection. They will face double jeopardy when a partner becomes ill, in the homeland and they have to continue with employment. The main aim of this research was to reach a holistic understanding through interdisciplinary investigation. The important question that I aim to answer is; “What is the experience of God in the lives of persons affected or infected by HIV and AIDS.” I have looked at Postfoundationalism and the Seven Movements as proposed by Muller to present the research undertaken among migrant workers with HIV and AIDS. The Practical Theology, which I explore, develops out of a very specific praxis, HIV and AIDS. I have also made used of Transversal Rationality as a practical way of doing interdisciplinary work with the stories of my co-researchers affected with HIV AIDS as a case study. I understand that Christian belief has its own integrity, which is exclusive, but if valid, is vital to be able to incorporate the different dimensions of our modern practise to give it the maximum level of meaning and significance. I hope to demonstrate this possibility through my thesis. / Thesis (PhD)--University of Pretoria, 2010. / Practical Theology / unrestricted

No description available.

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.

As keeping backyard poultry rises, human contact with zoonotic pathogens will increase. One such pathogen that backyard enthusiasts have exposure risks to is Salmonella spp. which may cause a potential public health threat due to its increasing multidrug resistancy. Salmonella spp. were present in 33 of 50 samples collected from 29 sites with backyard poultry coops in San Luis Obispo County during March to May in 2014. Two different Hardy-CHROME™ Salmonella Selective Media plates were used to culture and isolate positive samples of Salmonella spp.. Each positive isolate was tested for antimicrobial sensitivity to 6 standard antibiotics: Ampicillin, Bacitracin, Erythromycin, Gentamicin, Penicillin, and Tetracycline, at the standard disk concentration levels. The Kirby-Bauer antimicrobial sensitivity test determined that 12 different profiles emerged from the Salmonella spp. isolates. All antimicrobial sensitivity profiles showed multidrug resistance in vitro with only high susceptibility to 2 major antibiotics, Gentamicin at 97% and Ampicillin at 51%. All profiles were resistant to 1 or more of the antimicrobials tested, plus the control. One Salmonella isolated was resistant to all 6 antimicrobials and another isolate to 5. The Salmonella spp. isolates proved multidrug resistance between 73%-100% to the other 4 antibiotics tested. The 24 Salmonella spp. positive sites displayed a lack of proper biosecurity and poultry husbandry practices. The criteria developed for accessing the poultry’s environment ranged from dedicated shoes for cleaning, egg handling, access to other animals and wildlife, number of birds and breeds or species in a coop, cleaning routine, over-all biosecurity and human interactions. Human exposure to Salmonella spp. pathogenic strains could increase due to environmental cross contamination and deficiencies in sanitation. The presence of Salmonella spp. with a diversity of antibiotic resistance serotypes is an important source of zoonotic pathogens for animal and human diseases that has public health risk implications.

The continuous emergence of drug-resistance pathogens is a global concern. As a result, substantial effort is being expended to develop new therapeutics and mechanisms for controlling microbial growth to avoid entering a "post-antibiotic" era in which commonly used antibiotics are no longer effective in treating infections. In this work, we investigate the efficacy and application of ceragenins as non-peptide mimics of antimicrobial peptides (AMPs). First, this work examines the susceptibility of drug-resistant Gram-negative bacteria. The susceptibility of colistin-resistant clinical isolates of Klebsiella pneumoniae to ceragenins and AMPs suggests that there is little to no cross-resistance between colistin and ceragenins/AMPs. Furthermore, Lipid A modifications are found in bacteria with modest changes in susceptibility to ceragenins and with high levels of resistance to colistin. Next, we investigated the potential for cross resistance between chlorhexidine, colistin, AMPs and ceragenins as repeated exposure of bacteria to chlorhexidine might result in cross resistance with colistin, AMPs or ceragenins. Furthermore, a proteomics study on the chlorhexidine-resistant strains showed that chlorhexidine resistance is associated with upregulation of proteins involved in the assembly of LPS for outer membrane biogenesis and virulence factors in Pseudomonas aeruginosa.Second, this dissertation describes the antifungal activity of ceragenins against an emerging multidrug-resistant fungus, Candida auris. We found that lead ceragenins displayed activities comparable to known antifungal agents against C. auris isolates. We also found that fungal cell morphology was altered in response to ceragenin treatment, that ceragenins exhibited activity against sessile organisms in biofilms, and that gel and cream formulations including CSA-44 and CSA-131 resulted in a significant log reduction against established fungal infections in ex vivo mucosal tissues. Finally, a hydrogel film containing CSA-131 was generated on endotracheal tubes (ETTs). ETTs provide an abiotic surface on which bacteria and fungi form biofilms that cause serious infections. In this study, the eluting ceragenin prevented fungal and bacterial colonization of coated ETTs for extended periods while uncoated tubes were colonized by bacteria and fungi. Coated tubes were well tolerated in intubated pigs. The ability of ceragenins to eradicate established biofilms make them attractive potential therapeutics for persistent infections in the lung, including those associated with cystic fibrosis. In ex vivo studies, we initially found that this ceragenin, at concentrations necessary to eradicate established biofilms, also causes loss of cilia function. However, by formulating CSA-131 in poloxamer micelles, cilia damage was eliminated and antimicrobial activity was unaffected. These findings suggest that CSA-131, formulated in micelles, may act as a potential therapeutic for polymicrobial and biofilm-related infections in the lung and trachea.

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.