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There is a rapid spread of antibiotic resistance in the environment. However, the impact of antibiotic resistance in drinking water is relatively underexplored. Thus, this study aimed to quantify antibiotic resistance genes (ARGs) and antibiotic residues in two drinking water production facilities (NW-E and NW-C) in North West Province, South Africa and link these parameters to bacterial communities. Physicochemical and ARG levels were determined using standard procedures. Residues (antibiotics and fluconazole) and ARGs were quantified using ultra-high performance liquid chromatography (UHPLC) chemical analysis and real-time PCR, respectively. Bacterial community compositions were determined by high-throughput 16S rRNA sequencing. Data were analysed using redundancy analysis and pairwise correlation. Although some physicochemical levels were higher in treated than in raw water, drinking water in NW-E and NW-C was safe for human consumption using the South African Water Quality Guideline (SAWQG). ARGs were detected in raw and treated water. In NW-E, the concentrations of ARGs (sul1, intl1, EBC, FOX, ACC and DHA) were higher in treated water than in raw water. Regarding antimicrobial agents, antibiotic and fluconazole concentrations were higher in raw than in treated water. However, in NW-C, trimethoprim concentrations were higher in raw than in treated water. Redundancy analysis showed that bacterial communities were not significantly correlated (Monte Carlo simulations, p-value >0.05) with environmental factors. However, pairwise correlation showed significant differences (p-value <0.05) for Armatimonas, CL500-29 marine group, Clade III, Dickeya and Zymomonas genera with environmental factors. The presence of ARGs and antibiotic residues in the current study indicated that antibiotic resistance is not only a clinical phenomenon but also in environmental settings, particularly in drinking water niches. Consumption of NW-E and NW-C treated water may facilitate the spread of antibiotic resistance among consumers. Thus, regulating and monitoring ARGs and antibiotic residues in drinking water production facilities should be regarded as paramount. [ABSTRACT FROM AUTHOR]

Elevated concentrations of contaminants have negative impacts on aquatic organisms and their parasites. Changes in parasite infections have been proposed as a technique for monitoring the health of aquatic ecosystems. Furthermore, alterations in physiological responses (biomarkers) of organisms have also been used to delineate ecosystem quality. Lake Heritage is situated along the Crocodile River in Muldersdrift, Gauteng, South Africa, and is subject to contamination by acid mine drainage. Clarias gariepinus is a well-studied bioindicator species and host to numerous endoparasites and ectoparasites. The aims of this study were to delineate the health status of Lake Heritage through a multifaceted approach by comparing the water quality, biomarker responses, and parasite biodiversity of C. gariepinus, compared to unexposed laboratory-reared fish. Physical and chemical water quality parameters were determined using a hand-held probe, test kits, and element analysis with inductively coupled plasma-mass spectrometry. Biomarker responses in the gill, liver, and muscle tissues from C. gariepinus were assessed for total protein, metallothioneins, superoxide dismutase (SOD), and reduced glutathione (GSH) concentrations and activities of acetylcholinesterase and catalase. Results for water quality variables showed higher pH, nitrate, hardness, and copper levels compared with the South African Target Water Quality Guidelines. Catalase activity and concentrations of SOD and reduced GSH showed a response in C. gariepinus to the water quality. Ectoparasites had lower prevalence and mean intensity than endoparasites. However, there were no differences in the physiological responses between infected and uninfected hosts. The study shows that the eutrophic conditions in Lake Heritage cause biomarker responses in the host when compared to host fish in laboratory conditions. Integr Environ Assess Manag 2024;20:1539-1553. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)., (© 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).)

During 2012, aerial photographs of the Vaal River, South Africa, showed differences in water colour on either side of the Lethabo Weir. Water upstream of the weir was muddy brown, while water downstream was olive-green. Physical and chemical analyses indicated water quality differences upstream and downstream from the weir; furthermore, microscopic examination of water samples revealed that the colour difference were the result of different types of phytoplankton blooms. The upstream section was dominated by cryptophytes and green algae, while the downstream section experienced a cyanobacterial bloom dominated by Microcystis aeruginosa. The same phenomenon was again observed regularly between 2012 and 2022, and routine monitoring of the phytoplankton assemblage likewise indicated differences in the phytoplankton community composition upstream and downstream of the weir. The upstream section was characterised by various eukaryotic algae; in contrast, frequent and intensive cyanobacteria blooms occurred in the downstream section. Multivariate analyses showed a correlation between the different phytoplankton assemblages and physico-chemical properties of the river water. Many freshwater cyanobacteria and algae taxa are problematic: Microcystis and Dolichospermum produce potent cyanotoxins; flagellated green algae, cryptomonads and dinoflagellates produce substances that cause bad tastes and odours, plus the cells can cause floc disruption during drinking water treatment processes; and certain filamentous green algae and diatoms are known for clogging filters. [ABSTRACT FROM AUTHOR]

Purpose: Students completing their tertiary education at a university may be equipped with theoretical knowledge with little to no practical experience. In order to bridge this gap in practical skills, a computer simulation was developed based on the e-filing platform of the South African Revenue Services (SARS). Students were exposed to this self-developed computer simulation to answer the question: to what extent will the e-filing simulation improve students' confidence to practically apply their theoretical knowledge? Design/methodology/approach: The research applied a pre–post questionnaire research method to gauge the students' ability to apply their theoretical knowledge to a practical scenario before and after the simulation. Findings: From the results, it is apparent that the students were inspired with confidence in getting to terms with the application of their theoretical knowledge in a real-life scenario. The computer simulation provided the platform for learning to take place in a practical environment without the risk of errors that would translate into real financial consequences. Originality/value: The contribution of this research can be found in a teaching intervention that may support the training of future tax professionals in practical application skills. The contribution can be extended to the enhancement of education in the field of taxation, particularly with the results' showing that the students experienced high levels of increased confidence in their application of theoretical knowledge to real-life scenarios. [ABSTRACT FROM AUTHOR]

It has been suggested that parasites are effective bioindicators as they are sensitive to environmental changes and, in some cases, accumulate trace elements in higher concentrations than their hosts. Accumulated elements sequester in different organs. In monogenean and crustacean ectoparasites, sclerotised structures and egg yolk appear to be the preferred site for element sequestration. In this study, the sequestration of trace elements; Mg, Al, Ca, Fe, Cu, and Zn in Lamproglena clariae was studied from two rivers. Adult L. clariae were collected from the gills of Clarias gariepinus from Lake Heritage in the Crocodile River and in the Vaal River below the Vaal Dam, South Africa. Collected parasites were flash frozen in liquid nitrogen and sectioned with a cryomicrotome. Sections were treated with Phen-Green to observe fluorescent signals. Trace elements in the parasite were analysed using a scanning electron microscope with an energy-dispersive spectroscope (SEM–EDS). Results showed more intense fluorescence signals in the exoskeleton compared to tissues, and in the egg yolk. Analysis by SEM–EDS confirmed the presence of elements in the parasite from both sites. Levels of Al were higher in L. clariae from the Vaal River than those from Lake Heritage, and Fe was higher in L. clariae from Lake Heritage. Element distribution patterns in the parasite matched those in the water from the sites. Unlike other crustaceans, regulation of metals in adult females of L. clariae does not occur through moulting, but high levels occurred in the yolk. [ABSTRACT FROM AUTHOR]

This study report the presence of polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs) and novel brominated flame-retardants (NBFRs) in muscle tissues of Labeo capensis (mudfish), Labeo umbratus (moggel), Cyprinus carpio (carp) and Clarias gariepinus (catfish) from Vaal River, South Africa. The concentrations (in ng g−1 wet weight (ww)) of these contaminants ranged from LOQ to 12.8 ng g−1 ww in catfish, with lowest concentrations found for mudfish ranging from −1 ww. This variation was attributed to species-specific ecological status such as feeding habit and trophic level with BDE209 and BB209 as a major congeners among PBDEs and PBBs, respectively, and decabromodiphenyl ethane (DBDPE) as a major flame retardants among the NBFRs. The hazard quotients of these contaminants were very low indicating that these contaminants do not pose health risk to South Africans via fish consumption. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technologies and advances made globally in medicine, construction, aerospace, and energy sectors are discussed. The paper further explores the current state of AM innovation and development landscape in Africa as a late comer to this area of smart manufacturing. Peer-reviewed and published literature were retrieved from Scopus database from 2005 to 2021 and analysed. In Africa, out of 500 published articles, South Africa has the highest research throughput, whereas about two-thirds of the continent is not actively participating in this burgeoning field. The main AM techniques most widely used are selective laser melting, fused deposition modelling, and direct energy deposition. Globally, there is an interplay of computational (machine learning and mechanistic models) and experimental approaches to understanding the physical metallurgy of AM techniques and processes. Though this trend is consistent with global practices, Africa lags the world in AM technologies, a niche that could leapfrog the manufacturing sector. Thus, Africa need to foster collaborative partnership within and globally to become an active global player in this industry. [ABSTRACT FROM AUTHOR]

Anthropogenic activities influence the natural equilibrium of freshwater ecosystems resulting in negative ecological impacts. Differences in the infection variables of Lamproglena clariae in relation to variable water quality influenced by metal pollution were studied at six sites along the Vaal River, South Africa (March 2017 and October 2018). From each sampling site, in situ water quality parameters, water and sediment samples, and a minimum of 10 Clarias gariepinus were collected. Lamproglena clariae specimens collected from the gills of C. gariepinus were used to calculate the prevalence, mean intensity, and mean abundance of the parasite. Metal concentrations in water and sediment were analysed with inductively coupled plasma-optical emission spectrometry and inductively coupled plasma-mass spectrometry. Parasite intensity correlated negatively with some water quality parameters (conductivity, salinity, pH, total dissolved solids, and dissolved oxygen). Negative correlations were found between L. clariae (intensity and prevalence) and metal concentrations (Cu, Cr, Zn, Cd) in water. Parasite infections were influenced negatively at sites with high metal concentrations recorded in sediment and water and high levels of organic pollution. Sites that were found to be more polluted had lower mean intensity and mean abundance of L. clariae, indicating pollution affects the survival of this ectoparasite., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)