<p>Insects are continually exposed to potentially toxic endogenous compounds and xenobiotics that require rapid elimination from the body. Xenobiotic resistance in insects has evolved predominantly by increasing the activity of detoxification enzymes and/or by increasing toxin excretion via the Malpighian (renal) tubules. The tubules have long been known to transport organic anions at high rates. This thesis examines the mechanisms of excretion and detoxification of the organic anion methotrexate (MTX) by isolated tissues of the fruit fly <em>Drosophila melanogaster</em>. A radioisotope tracer technique and the Ramsay assay were used to measure MTX secretion. Quantitative PCR (qPCR) was used to evaluate the expression of the genes for putative organic anion transporters. My results show that MTX transport across the Malpighian tubule epithelium is active, saturable, Na⁺-independent and inhibited by a wide range of organic anions including MK-571, probenecid and Texas Red. Pharmacological studies and qPCR analyses suggest multiple transporters are involved in the movement of MTX across the Malpighian tubules. Moreover, chronic exposure of larvae to dietary MTX or salicylate dramatically increases the transepithelial transport of MTX by isolated Malpighian tubules, suggesting that excretion of MTX is upregulated by exposure to these organic anions in the diet. In addition, treatments known to increase expression of specific detoxification enzymes, such as the P450 monoxygenases (P450s) and the glutathione-S-transferases (GSTs), also led to an increase in expression levels of multidrug efflux transporter (MET), multidrug resistance like protein 1 (dMRP) as well as to increased secretion of MTX by the tubules. This latter finding suggests a coordinated response to toxin exposure, so that when detoxification pathways are increased, there is a corresponding increase in the capacity for elimination of the products of P450 and GST enzymes. Finally, the last section of this thesis has shown that RNAi knockdown of a single organic anion transporter gene in the principal cells of <em>D. melanogaster</em> Malpighian tubules is associated with reductions in the expression of multiple, functionally-related genes. Importantly, these results indicate that dMRP andMET are not the dominantMTX transporters in the tubules when flies are reared onMTX-enriched diets. However, reductions in the expression of organic anion transporting polypeptide (OATP) are associated with reduced secretion of the organic anionsMTX, fluorescein and Texas Red. Taken together, these results suggest that OATP and at least one additional transporter, as yet unidentified, are required forMTX secretion. In conclusion, the results of my research contribute to our understanding of the mechanisms of organic anion detoxification and excretion in flies exposed to dietary toxins.</p> / Doctor of Science (PhD)

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.

Magister Public Health - MPH / Background: Multidrug resistant tuberculosis (MDR TB) is a growing threat globally. The large increase in the incidence and prevalence of MDR TB in South Africa in recent years has impacted on the way in which MDR TB is managed within the health services. It became logistically difficult to manage MDR TB by treating all patients as in-patients in a specialized tuberculosis (TB) hospital. The clinics, which are run by nurses and/or general medical officers, are then required to manage this more complex form of TB, with limited resources, less experience and assumingly with less MDR TB knowledge. Of particular concern is that shifting of the patient management from specialized TB hospitals to Primary Health Care clinics which might worsen the already poor MDR TB treatment outcomes. There has been minimal assessment of the management of MDR TB at clinic level and hence the comparison of treatment outcomes for those patients initiated on treatment in clinics compared to in-patients in specialized TB hospitals is urgently needed. Aim: To compare the treatment outcomes and the effectiveness of medication regimens provided to MDR TB patients initiated on treatment in specialized TB hospitals as inpatients, to that of MDR TB patients initiated on treatment as outpatients at community clinics within the Western Cape Province, South Africa. Methodology Study Design: A retrospective cohort study was undertaken, as the length of treatment for a MDR TB patient can be for 24 months or longer and this study was based on treatment outcome data. Study Population and sample: The study population was uncomplicated MDR TB patients initiated on treatment in hospitals and clinics from January 2010 to December 2012. The sample comprised of 568 participants that were laboratory confirmed to have MDR TB and had the outcomes of their treatment recorded in an electronic database or a paper register. Data Collection: The researcher collected MDR TB information from standardized MDR TB registers as well as an electronic MDR TB database. Analysis: Data was analyzed comparing the exposed (clinic initiated) and unexposed (hospital initiated) cohorts incidence of 4 key treatment outcomes, namely: successfully treated, failed treatment, died and defaulted treatment. Bivariate analysis (relative and absolute) was done to determine the cumulative incidence ratio and cumulative incidence difference and multivariate logistic regression analysis for the adjusted odds ratio to control for confounders and effect modifiers. Ethics: Permission to conduct this research was obtained from the relevant authorities. The confidentiality of the participants as per the Department of Health policy and in adherence to general ethical guidelines was strictly maintained. The study proposal received ethical clearance and approval from the University of the Western Cape Research Committee. Results: All participants within this study received the appropriate treatment as per the MDR TB guidelines. The incidence rate for the main outcomes of this study indicated that successfully treated for the clinic initiated participants was 41% and 31% for the hospital initiated participants. ‘Defaulted’ treatment was 39% and 41%, ‘failed’ treatment 7% and 13% and ‘died’ was 14% and 16%, respectively. The clinic initiated participants appeared to have better treatment outcomes on bivariate analysis, however on multivariate analysis, there was no difference in the treatment outcomes of the clinic initiated participants compared to the hospital initiated participants, and therefore the clinic initiated treatment is seen as effective. The time to treatment initiation for clinic and hospital initiated participants is excessively long for both cohorts, with a median of 29 days, and 37 days respectively. The key findings of note in the multivariate analysis is that the Human Immunodeficiency Virus positive (HIV+) participants provided with antiretrovirals therapy (ART) were, based on adjusted cumulative incidence ratios, 6.6 times more likely to have a successfully treated outcome (95% CI 1.48-29.84), and were 0.2 times less likely to die (95% CI 0.08-0.53). Having a previous cured history of TB and no previous history of TB were 2.9 times more likely to have a successfully treated outcome (95% CI 1.48-5.56) and were 0.1 times (0.04-0.38) less likely to fail treatment. An interesting finding was that participants living in the rural districts were 2.6 times more likely to die. Conclusion: Clinic initiated treatment for uncomplicated MDR TB is as effective as hospital initiated treatment. Also, those provided with ART and those without previous TB or who had a previous bout of TB cured, had better outcomes. Main Recommendations: The Western Cape health department should continue with the decentralization of MDR TB services to the clinics and could safely consider expanding the decentralization to include uncomplicated Preextensively drug-resistant TB and Extensively drug-resistant TB patients. Offering ART to HIV+ patients should be mandatory. The delays in the time to treatment initiation of MDR TB need to be further investigated.

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.

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.

Tuberculosis remains a major public health issue globally, with an estimated 9.2 million new cases in 2006. A new threat to TB control is the emergence of drug resistant strains. These strains are harder to cure as standard anti-tuberculosis first line treatments are ineffective. Multi Drug Resistant Tuberculosis (MDR-TB) is defined as Mycobacterium tuberculosis that has developed resistance to at least rifampicin and isoniazid, and these strains now account for greater than 5% of worldwide cases. Mutations within the Rifampicin Resistance Determining Region (RRDR) of the rpoB gene are present in greater than 95% of strains that show rifampicin resistance by conventional drug susceptibility testing. As rifampicin mono resistance is extremely rare, and rifampicin resistance is usually associated with isoniaizd resistance, the RRDR region of the rpoB gene is a very useful surrogate marker for MDR-TB. Many molecular assays have been attempted based on this theory and have had varied levels of success. The three methods evaluated in this study are DNA sequencing of the rpoB, katG and inhA genes, the Genotype MTBDRplus line probe assay (Hain Lifesciences) and a novel method incorporating Real-Time PCR with High Resolution Melt analysis targeted at the RRDR using the Rotorgene 6000 (Corbett Lifesciences). The sensitivity for the detection of rifampicin resistance was far better using DNA sequencing or the commercially available line probe assay than detection by the Real-Time PCR method developed in this study.

The purpose of the study was to investigate and describe the experiences of a mobile injection team for multi drug resistant-tuberculosis outpatients, and to design and recommend a mobile injection team guideline based on the experiences of the team members in Ugu District, KwaZulu-Natal and to indicate the support that the MIT require. Phenomenological research was conducted. Convenient census sampling was used as all the seven members of the Ugu District mobile injection team were included. The inclusion criteria was at least six months’ working experience with MDR-TB patients in a mobile injection team at Ugu District, be an enrolled nurse registered with the South African Nursing Council as an enrolled nurse and must have an annual practicing certificate, or be a TB assistant, be willing to participate in the study and be located at the decentralised and satellite site. Data were collected through individual in-depth interviews with the participants. Data were analysed using Giorgi’s method of data analysis. The research findings revealed four broad themes (the perceptions held by the team, challenges, available support and needs to promote the service) and 73 sub-themes. The findings of the study indicate that the MDR-TB outreach injection teams experience many challenges in the community and need to be supported by their management in order to provide quality care to the patients. This study contributes to the development of guidelines to assist the mobile injection teams to provide quality patient care and effective service delivery. Based on the findings, the recommendation is that an intervention study be performed to compare the utilisation of the mobile MDR-TB injection team after implementing the recommendations made and the guidelines developed in this study / Health Studies / D. Litt. et Phil. (Health Studies)