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Anthropogenic disturbances of soil environments predispose loss of soil ecosystem functions, including its habitat support function. In this study, the potential ecosystem support and habitat functions of soils from stockpiles and post-mining reclamation areas (ranging from 3 to 25 years) in two coal mining sites were assessed using Eisenia andrei bioassays. Endpoints such as avoidance response, mortality, relative growth rate and fecundity were determined. By taking into cognisance the ages of the reclamation areas, inference was drawn on the potential restoration of ecosystem support functions over the years since reclamation. Mortality and fecundity of earthworms did not suggest limited support functions of control and test soils. Net avoidance response (AR) indicated significant differences (P < 0.05) among treatments with only the net AR in a 3-year old reclaimed soil >80%. Earthworms generally preferred (P < 0.05) undisturbed (“reference”) soils to OECD and test soils. Furthermore, trends in AR suggested a negative effect (P < 0.05) of anthropogenic disturbance and a general improvement of soil habitat function in older reclaimed areas. Of all endpoints, the avoidance test was the most sensitive, which generally reflected the differences in soil physicochemical properties among test soils. Although high intra-site variations in soil properties suggest lack of strict adherence to best reclamation practices, coal mining soil environments are not ecologically derelict with regards to supporting biocoenosis

AAfter a cluster of human pneumonia cases in Wuhan City (China) on 7 January 2020, a novel coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), was identified as the causative agent of the disease COVID‐19 (World Health Organization 2020). It quickly became a global pandemic and continues to rapidly spread across the world, having infected almost 4 million confirmed cases and caused more than 265 000 deaths at time of publication, far surpassing the total cases of SARS and Middle East respiratory syndrome (MERS)

Antimicrobial resistance is an imminent threat to the effective prevention and treatment of bacterial infections and alternative antimicrobial strategies are desperately needed. Antimicrobial peptides (AMPs) may be promising alternatives to current antibiotics or act as adjuvants to enhance antibiotic potency. Additionally, the use of biodegradable lipid nanoparticles can enhance the antibacterial activity of antibiotics and antimicrobial peptides. In this study, the interaction of the AMPs, nisin Z and melittin, with conventional antibiotics was investigated on Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli. The effectiveness of nanostructured lipid carriers (NLCs) for the entrapment of nisin Z was also evaluated. Findings revealed that nisin Z exhibited additive interactions with numerous conventional antibiotics. Notable synergism was observed for novobiocin-nisin Z combinations. The addition of the non-antibiotic adjuvant EDTA significantly improved the antimicrobial activity of free nisin Z towards E.coli. NLCs containing nisin Z were effective against Gram-positive species at physiological pH, with an increase in effectiveness in the presence of EDTA. Results indicate that nisin Z may be advantageous as an adjuvant in antimicrobial chemotherapy, while contributing in the battle against antibiotic resistance. NLCs have the potential to enhance the antibacterial activity of nisin Z towards Gram-positive bacterial species associated with skin infections

A series of aminoferrocenyl–chalcone amides 11–19 were synthesized through condensation of a carboxylic acid-functionalized chalcone 10 with ferrocenylamines, using 1,1′-carbonyldiimidazole as the coupling agent. The compounds were screened for their antiplasmodial activities against CQS 3D7 and CQR FCR3 strains of Plasmodium falciparum. All compounds were found to be active, with IC50 values ranging between 0.5–4.5 and 2.1–6.6 µM against 3D7 and FCR3, respectively. Amide 11, featuring a 2-aminoethylene linker, was the most active of all, with IC50 values of 2.6 and 2.1 µM against the 3D7 and FCR3 strains, respectively. In screens against a panel of three cancer cell lines, i.e., TK-10, UACC-62, and MCF-7, amide 19, with a piperazinyl linker, showed increased activity against all three cell lines, compared to the reference drug, parthenolide. Antimicrobial assays that had been performed on six different microorganisms revealed that most of the synthesized amides were inactive against all of these microorganisms. Compound 17, however, with an aminodi(ethyleneoxy) linker, displayed moderate bactericidal activity against the gram-negative microorganisms, with a MIC100 value of 128 µM. The outcomes of this study may hence significantly contribute toward malaria and cancer chemotherapy research, and more generally to the growing body of research that aims at illustrating the potential of employing organometallic compounds in medicinal chemistry programs

Many South Africans do not have access to safe drinking water, so they have no alternative but to use water from contaminated sources that poses a health hazard. This poor state of affairs appears to be deteriorating. In order to distinguish safe from unsafe sources, the aim of this study was to adapt the well-known MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay into a simple and efficient method to screen the suitability of drinking water without needing to know the nature of any possible contamination. This modified assay presents an immediate and reliable answer to whether water is potable without recourse to standard chemical and microbiological water-quality tests. The MTT assay was used here for the first time to test the effects of microbes, and not chemical contaminants as is traditionally the case, on the viability of human duodenum cells exposed to water samples of interest. Filtered tap water and water from a borehole, for example, had limited adverse effects on cell viability. Cell viability decreased greatly after exposure to dam, treated sewage and river water which confirmed the value of the assay as a screening tool

DNA barcoding was used to investigate the phylogenetic delimitations of Eisenia sp field populations and laboratory cultures used in ecotoxicological research in South Africa. A total of three focal groups (used in published works) and two non-focal groups were assessed. These focal groups, including two laboratory cultures and one field population, have been referred to as Eisenia fetida in the literature. Phylogenetic analyses of the COI gene revealed that the taxonomy of these Eisenia sp had been incorrectly assigned since all the generated sequences grouped unequivocally with published sequences of E. andrei. Very high sequence divergence (> 25% K2P) found within E. andrei could signal the occurrence of hitherto non-described cryptic species. These findings are discussed with an emphasis on the possible consequences of using conspecific earthworms specimens with high molecular divergence in ecotoxicological bioassays. It is not clear whether unbeknownst to the researcher, the use of cryptic species in bioassays could jeopardise the quality of ecotoxicological investigations. Early evidence suggests that cryptic oligochaete species may respond differently to metal toxicity. The need for comparative ecotoxicological studies between E. andrei and E. fetida is also evidenced, especially in the light of recent numerous reports of cryptic oligochaete species. Ecotoxicologists are consequently encouraged, whenever possible, to make use of available genomic technologies to screen their laboratory stocks and available field populations for any molecular distinctiveness.

DNA barcoding was used to investigate laboratory and commercial stocks of Eisenia species from four provinces of South Africa. The COI gene was partially amplified and sequenced in selected earthworms from eight local populations (focal groups) and two European laboratory stocks (non-focal groups). Only nine COI haplotypes were identified from the 224 sequences generated. One of these haplotypes was found to belong to the megascolecid Perionyx excavatus. The remaining eight haplotypes belonged to the genus Eisenia, although only a single E. fetida haplotype, represented by six specimens, was found in one of the European populations. The other seven haplotypes, all occurring in South Africa, were E. andrei. One of the commercial stocks from South Africa and a laboratory culture from Europe were mixtures of E. andrei – P. excavatus and E. andrei – E. fetida, respectively. Previous allozyme studies have helped to suggest that some of the populations included in this study may be suffering from inbreeding depression, which could result in adverse consequences for both the vermiculture industry and ecotoxicological research in South Africa.