Monitoring of microcystin-LR in Luvuvhu River catchment: Implications for human health

Cyanotoxins in surface drinking water sources are known to pose a threat to human health, of which microcystin-LR is the most investigated. The main aim of this study is to assess the levels of microcystin-LR in Luvuvhu River catchment and to assess the physicochemical parameters that maypromote the growth of cyanobacteria. The level of microcystin-LR in some of the sampling sites was <0.18 ìg/l except for one site (Luvuvhu River just before the confluence of Dzindi and Mvudi Rivers) which had a reading of 2 ìg/l during August, 2009. Though the results indicated that some of the sites, especially on the Mvudi River system, had high nutrient levels, alkaline pH and water temperature <24°C, the levels of microcystin-LR were <0.18 ìg/l. The production and release of microcystin-LR into water bodies by different strains of cyanobacteria involves a complex relationship between environmental variables. The water quality of the shallow hand dug wells and reservoir water were almost similar. The outflows had slightly high levels of nitrates and no soluble reactive phosphates in comparison with inflows, suggesting that the phosphates were being incorporated into the sediments. This could be a potential danger if the climatic conditions were to change and as this will promote the proliferation of nitrogen fixing cyanobacteria. Maybe, the non availability of phosphorous which is known to be a limiting nutrient in freshwater systems, could have contributed to no cyanobacteria blooms. Thus, the domestic consumption of these surface water sources may be a potential health hazard to the rural communities as it exposes the users to low levels of cyanotoxins over a long term.Key words: Nutrient enrichment, microcystin, sediments, cyanobacteria

A Review: Assessment of Trace Metals in Municipal Sewage and Sludge: A Case Study of Limpopo Province, South Africa

Trace metals including nanosilver in our aquatic environment are on the increase in part due to discharge from municipal sewage and indirectly from leaching from abandoned mine tailings and from sludge spread on farmland. The presence of the trace metals will likely impact negatively on the aquatic environment in excess of background levels. This review reports on the concentration of trace metals in municipal sewage in Limpopo province and the impact on fish and human health. Human health risks associated with the consumption of contaminated fish are discussed. The presence of silver is also highlighted and the remedial actions that are available in reducing the health risks including positive outcomes are discussed. The source of silver may be from the use of silver nanoproducts. There is a need for a paradigm shift of zero effluent discharge and start with harvesting of metals from the sewage effluent and sludge in order to protect the environment

The relevance of indigenous technology in curriculum 2005/RNCS with special reference to the technology learning area

In this article it is argued that indigenous technology with its long history cannot be ignored and should be as signed a more prominent place in the Technology Learning Area (TLA) within Curriculum 2005/RNCS Grades R – 9.2 The argument is based on the findings of a study in which the relevance of indigenous technology in the TLA curriculum was investigated. The findings not only pointed to the long history of indigenous technology, but also evidenced the continued use of such technology among indigenous people, especially in the rural contexts. The findings in the study are suggestive of an enhanced recognition of indigenous technology in the TLA curriculum. Therefore, informed by the findings, the authors pose certain recommendations pertaining to the TLA curriculum.The article has as secondary purpose creation of awareness of, and sensitivity for, the cultural heritage of indigenous people in South Africa and context-specific community needs which can be recognised and addressed in learning areas such as the TLA.South African Journal of Education Vol. 26 (4) 2006: pp. 501-51

An investigation of the bioaccumulation of chromium and uranium metals by Cynodon dactylon: A case study of abandoned New Union Gold Mine Tailings, Limpopo, South Africa

Mine waste, including tailings is generally outlined as one of the largest environmental concern which faces defunct mines in South Africa and New Union Gold Mine is no exception. These tailing contain heavy metal such as chromium (Cr) and uranium (U) which poses enormous threat to the environment even at small quantity. The study focuses mainly on bioaccumulation of Cr and U in soil by Cynodon dactylon, an indigenous grass. The grass and soil sample were collected at New Union Gold Mine and Ka-Madonsi Village at Malamulele, Limpopo Province, South Africa. The concentration of Cr and U were determined with a Thermofischer ICP MS. The research findings indicate that the range in the levels of Cr and U at mine tailings dam A were 152.60 to 196.12 mg/kg and 0.51 to 0.92 μg/gm, respectively. The ranges in the levels of Cr and U at mine tailings dam B were 151.34 to 229.67 mg/kg and 0.85 to 1.06 μg/g, respectively. The levels of Cr and U at the control site were 81.31 mg/kg and 0.73 μg/g. The pH of mine tailing dam A was 3.23 to 3.34 and for tailing dam B were, 3.25 to 3.29 making both tailing acidic while for the control site, it was slightly alkaline at 7.56. The bioconcentration and translation factors of C. dactylon were variable but were dependent on pH conditions. Thus, C. dactylon was able to bioaccumulate toxic metals Cr and U from the mine tailings making them potential phytoremediation agent for the rehabilitation of exposed mine tailings. This is important in covering the mine tailings since any exposed part of mine tailings is liable to water and wind erosion. Thus, Cr and U may be exported to external environment such as aquatic ecosystem and neighboring rural communities with negative impacts.Key words: Phytoremediation, chromium, uranium, indigenous grass, dysfunctional mine tailings

The challenge of integrated water resource management for improved rural livelihoods: Managing risk, mitigating drought and improving water productivity in the water scarce Limpopo Basin

The Challenge of Integrated Water Resource Management for Improved Rural Livelihoods: Managing Risk, Mitigating Drought and Improving Water Productivity in the Water Scarce Limpopo Basin: Integrated Water Resources Management (IWRM) is a systems approach to water management, based on the principle of managing the full water cycle. It is required, not only to balance water for food and nature, but also to unlock paths to sustainable development. A global hotspot area in terms of water for food and improved livelihoods is in the poverty stricken rural areas of water scarce semi-arid tropics, such as in the Limpopo basin. The improvement in resilience that the IWRM approach can impart to rural livelihood systems has been shown by a series of case studies in the Limpopo Basin

THE PRELIMINARY ASSESSMENT OF ANTI-MICROBIAL ACTIVITY OF HPLC SEPARATED COMPONENTS OF KIRKIA WILMSII

Background: Most communities in developing countries rely on traditional medicines for the treatment of diseases. In South Africa, the Limpopo province, within the Lebowakgomo district, uses tuberous roots of Kirkia wilmsii, after infusion in water for the treatment of a wide range of diseases by Sotho communities. Materials and Methods: The main objective of the study was to assess the anti-microbial activity of separated aqueous components of the Kirkia wilmsii tuberous roots. The clear aqueous extracts that were obtained after a 0.45 µm membrane filtration (Millipore Millex-HV Hydrophillic PVDF filter), were then injected into a preparative high performance liquid chromatography instrument in which pure components, as shown by peaks, were collected and evaluated for anti-microbial activity against a range of microorganisms. Results: The eight separated components were obtained, out of which four components showed anti-microbial activity (AMA). The freeze dried components were re-dissolved in deionised water and then evaluated for AMA against Vibrio cholerae, Shigella dysenteriae, Aeromonas hydrophilia, Salmonella typhi Proteus mirabilis, Escherichia coli, Staphylococcus aureus, Candida albicans and Enterobacter aerogenes. Component one exhibited antimicrobial activity against Shigella dysenteriae, Aeromonas hydrophilia, Salmonella typhi, Proteus mirabilis, Escherichia coli and Staphylococcus aureus with a minimum inhibitory concentration (MIC), of 3.445 mg/ml. Component five was only active against Proteus mirabilis with a MIC of 0.08 mg/ml. Component 7, was active against Shigella dysenteriae, Staphylococcus aureus and Escherichia coli with a MIC of 0.365 mg/ml against both Shigella dysenteriae and Staphylococcus aureus and 0.091 mg/ml against Escherichia coli. Component 8, was active against Shigella, Aeromonas hydrophilia, Salmonella, Proteus mirabilis, Escherichia coli with a MIC of 155 mg/ml. Conclusion: Only four out of eight aqueous extracts showed AMA against both gram negative and positive bacteria and showed no AMA against Candida albicans, Enterobacter aerogenes and Vibrio cholerae. Therefore the Kirkia wilmsii plant root may be used as a broad spectrum antibiotic

Integrating pharmacokinetics and pharmacodynamics in operational research to end tuberculosis

Tuberculosis (TB) elimination requires innovative approaches. The new Global Tuberculosis Network (GTN) aims to conduct research on key unmet therapeutic and diagnostic needs in the field of TB elimination using multidisciplinary, multisectorial approaches. The TB Pharmacology section within the new GTN aims to detect and study the current knowledge gaps, test potential solutions using human pharmacokinetics informed through preclinical infection systems, and return those findings to the bedside. Moreover, this approach would allow prospective identification and validation of optimal shorter therapeutic durations with new regimens. Optimized treatment using available and repurposed drugs may have an increased impact when prioritizing a personcentered approach and acknowledge the importance of age, gender, comorbidities, and both social and programmatic environments. In this viewpoint article, we present an in-depth discussion on how TB pharmacology and the related strategies will contribute to TB elimination

Drug Concentration Thresholds Predictive of Therapy Failure and Death in Children With Tuberculosis: Bread Crumb Trails in Random Forests

Children with tuberculosis are treated with drug regimens copied from adults despite significant differences in antibiotic pharmacokinetics, pathology, and the microbial burden between childhood and adult tuberculosis. We sought to develop a new and effective oral treatment regimen specific to children of different ages. We investigated and validated the concept that target drug concentrations associated with therapy failure and death in children are different from those of adults. On that basis, we proposed a 4-step program to rapidly develop treatment regimens for children. First, target drug concentrations for optimal efficacy are derived from preclinical models of disseminated tuberculosis that recapitulate pediatric pharmacokinetics, starting with monotherapy. Second, 2-drug combinations were examined for zones of synergy, antagonism, and additivity based on a whole exposure–response surface. Exposures associated with additivity or synergy were then combined and the regimen was compared to standard therapy. Third, several exposures of the third drug were added, and a 3-drug regimen was identified based on kill slopes in comparison to standard therapy. Fourth, computer-aided clinical trial simulations are used to identify clinical doses that achieve these kill rates in children in different age groups. The proposed program led to the development of a 3-drug combination regimen for children from scratch, independent of adult regimens, in <2 years. The regimens and doses can be tested in animal models and in clinical trials

Survival of HIV Infected Children Born to Mothers Enrolled in a PMTCT Program in a Resource Poor Setting *

ABSTRACT Background: Pediatric HIV is a leading cause of morbidity and mortality worldwide. The substantial expansion in PMTCT has generated information on rates of transmission and associated factors, but there are limited studies on disease progression and mortality in vertically infected children, especially from resource poor settings. Methods: A birth cohort study was initiated in 2002 to focus on the role of a single dose of nevirapine in HIV transmission before Highly Active Antiretroviral Therapy (HAART) was readily available. The enrolment of women and subsequent follow up of the children occurred at 3 peri urban clinics around Harare. Findings: 479 women were HIV infected. From these, 93 (19%) children became HIV infected, 182 (38.0%) uninfected and 204 (43%) lost to follow up before HIV diagnosis. Of the HIV infected children, 40 (43%) died before the fifth birthday, 26 (28%) were lost to follow up and 27 (29%) were alive five years after maternal enrolment prior to availability of cART. Conclusion: In this setting, there was unacceptable high mortality from HIV infected children and loss to follow up prior to availability of HAART. A small proportion of HIV vertically infected children is surviving in resource poor settings without antiretroviral therapy