Research Articles (Biochemistry, Genetics and Microbiology (BGM))

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The ATM kinase inhibitor AZD0156 is a potent inhibitor of Plasmodium falciparum phosphatidylinositol 4-kinase (PI4Kβ) and is an attractive candidate for medicinal chemistry optimization against malaria
(Wiley, 2025-07) Woodland, John G.; Coertzen, Dina; Wicht, Kathryn J.; Hidalgo, Virginia Franco; Pasaje, Charisse Flerida A.; Godoy, Luiz C.; Qahash, Tarrick; Mmonwa, Mmakwena M.; Dziwornu, Godwin A.; Wambua, Lynn; Harries, Sarah; Korkor, Constance M.; Njoroge, Mathew; Krugmann, Liezl; Taylor, Dale; Leshabane, Meta Kgaogelo; Langeveld, Henrico; Rabie, Tayla Anne; Reader, Janette; Van der Watt, Mariette Elizabeth; Venter, Nelius; Erlank, Erica; Aswat, Ayesha S.; Koekemoer, Lizette L.; Yeo, Tomas; Jeon, Jin H.; Fidock, David A.; Gamo, Francisco Javier; Wittlin, Sergio; Niles, Jacquin C.; Llinas, Manuel; Coulson, Lauren B.; Birkholtz, Lyn-Marie; Chibale, Kelly; lynmarie.birkholtz@up.ac.za
New compounds targeting human malaria parasites are critical for effective malaria control and elimination. Here, we pursued the imidazoquinolinone AZD0156 (MMV1580483), a human ataxia-telangiectasia mutated (ATM) kinase inhibitor that completed Phase I clinical trials as an anticancer agent. We validated its in vitro activity against the two main forms of the Plasmodium falciparum parasite in the human host, viz. the asexual blood (symptomatic) stage and sexual gametocyte (transmission) stage. Resistance selection, cross-resistance, biochemical, and conditional knockdown studies revealed that AZD0156 inhibits P. falciparum phosphatidylinositol 4-kinase type III beta (PfPI4Kβ), a clinically-validated target for the treatment of malaria. Metabolic perturbations, fixed-ratio isobolograms, killing kinetics and morphological evaluation correlated AZD0156 inhibition with other known PI4Kβ inhibitors. The compound showed favorable in vivo pharmacokinetic properties and 81% antimalarial efficacy (4 × 50 mg kg−1) in a P. berghei mouse malaria infection model. Importantly, a cleaner biochemical profile was measured against human kinases (MAP4K4, MINK1) implicated in embryofoetal developmental toxicity associated with the PfPI4Kβ inhibitor MMV390048. This improved kinase selectivity profile and structural differentiation from other PI4Kβ inhibitors, together with its multistage antiplasmodial activity and favorable pharmacokinetic properties, makes AZD0156 an attractive candidate for target-based drug repositioning against malaria via a medicinal chemistry optimization approach.
Uncovering cryptic species diversity of Ophiocordyceps (Ophiocordycipitaceae) associated with Coleoptera from Thailand
(Westerdijk Fungal Biodiversity Institute, 2024-12) Mongkolsamrit, S.; Noisripoom, W.; Tasanathai, K.; Khonsanit, A.; Thanakitpipattana, D.; Lamlertthon, S.; Himaman, W.; Crous, Pedro W.; Stadler, M.; Luangsa-ard, J.J.
This study advances our understanding of Ophiocordyceps, an extensively studied entomopathogenic fungus within the Ophiocordycipitaceae, particularly in Thailand. We introduce seven novel species associated with Coleoptera - O. albostroma, O. brunnea, O. capilliformis, O. kohchangensis, O. phitsanulokensis, O. pseudovariabilis, and O. ratchaburiensis. Remarkably, O. brunnea, O. kohchangensis, and O. ratchaburiensis exhibit ascomata on the subterminal region of the stromata, with the asexual form appearing at the apex of the stipe, reminiscent of O. brunneipunctata. In contrast, O. phitsanulokensis produces its ascomata in the upper region of the stipe. Shared traits include immersed perithecia and part-spores production. Ophiocordyceps albostroma and O. pseudovariabilis produce pseudo-immersed perithecia, with the former producing ascospores breaking into four part-spores, and the latter displaying 32 part-spores. Ophiocordyceps capilliformis is also introduced due to morphological distinctions from closely related species. Phylogenetic analyses based on multigene loci (LSU, TEF1, RPB1, RPB2) robustly confirm the placement of these new species within Ophiocordyceps. Additionally, we report a new record of O. clavata in Thailand.
A phylogenetic assessment of Akanthomyces sensu lato in Cordycipitaceae (Hypocreales, Sordariomycetes) : introduction of new genera, and the resurrection of Lecanicillium
(Westerdijk Fungal Biodiversity Institute, 2024-12) Khonsanit, A.; Thanakitpipattana, D.; Mongkolsamrit, S.; Kobmoo, N.; Phosrithong, N.; Samson, R.A.; Crous, Pedro W.; Luangsa-ard, J.J.
During entomopathogenic fungal surveys conducted in Thailand, 15 specimens tentatively classified under Akanthomyces sensu lato were identified. To gain a comprehensive understanding of their taxonomy, molecular phylogenies using combined LSU, TEF1, RPB1, and RPB2 sequence data, together with morphological examination of several Akanthomyces spp. from previous studies were conducted. The analyses revealed distinct clades representing independent lineages within the Cordycipitaceae. These clades were further characterized by different asexual morph types and the respective hosts they parasitize. In this context, we resurrected the genus Lecanicillium to accommodate 12 known species previously classified under Akanthomyces sensu lato, found on diverse hosts. We propose four new genera - Corniculantispora, Corpulentispora, Zarea, and Zouia - from species previously identified as Lecanicillium. Notably, certain Akanthomyces species associated with spiders and parasitic on Ophiocordyceps sinensis were reclassified into the new genera Arachnidicola and Kanoksria, respectively. Moreover, we introduce four novel species in Akanthomyces sensu stricto found across a diverse range of moth families: Ak. buriramensis, Ak. fusiformis, Ak. niveus, and Ak. phariformis. Additionally, we provide descriptions and illustrations of the sexual morph linked to Ak. laosensis and Ak. pseudonoctuidarum, along with a second type of synnemata seen in Ak. noctuidarum and Ak. pseudonoctuidarum. To assist with their identification, keys to the genera Akanthomyces, Arachnidicola, and Lecanicillium are provided, but should not be used to replace molecular identification
Endophytic diaporthe species from Brazil
(Westerdijk Fungal Biodiversity Institute, 2024-12) Ferro, L.O.; Bezerra, J.D.P.; Da Silva, T.M.; De Oliveira, C.S.; Nascimento, S.dosS.; Paiva, L.M.; Fan, x.; Crous, Pedro W.; Souza-Motta, C.M.
Diaporthe species can inhabit various hosts with different lifestyles and live as endophytes, pathogens, and saprobes. Our study analysed 180 endophytic Diaporthe isolates from Miconia sp. in the Atlantic Forest, Brosimum gaudichaudii in the Brazilian savanna (Cerrado), and Anacardium occidentale in the Caatinga forest and Cerrado in Brazil. Based on multi-locus phylogenetic analyses [β-tubulin (tub2), internal transcribed spacer regions and intervening 5.8S rRNA (ITS), translation elongation factor 1-alpha (tef1), calmodulin (cmdA), and histone (his3)] and morphological features, we are introducing seven new species (D. azevedoi, D. catimbauensis, D. coracoralinae, D. luizorum, D. pedratalhadensis, D. samambaiaensis, and D. vargemgrandensis) and reporting seven known species (D. fructicola, D. inconspicua, D. infertilis, D. paranensis, D. raonikayaporum, D. schini, and D. ueckeri). We also included a morphological description of D. infertilis and synonymised D. lutescens, D. pseudoinconspicua, and D. samaneae under D. inconspicua; D. neoraonikayoporum under D. raonikayaporum; and D. passifloricola, D. rosae, and D. vochysiae under D. ueckeri, based on limited nucleotide differences among DNA sequence data and overlapping morphological features. Our results highlight the importance of including endophytic isolates in the phylogeny of Diaporthe, and show how these data expand the geographic distribution and host relationships of known species.
Historical constraints and heterospecific interference lead to maladaptive sex ratio changes in a pollinating fig wasp
(Royal Society, 2025-07) Greeff, Jacobus Maree; Mnguni, Simiso Polite; Warren, Marie
Natural selection’s power is beautifully illustrated by sex ratio variation that seems near-perfectly adapted. However, the fit of sex ratios to optimal predictions is usually tested in oversimplified ecological settings. This creates a one-sided view of evolution, where details are ignored, and evolution appears to produce optimal solutions. Entertaining maladaptation as a potential explanation allows consideration of historical contingencies and trade-offs. These become important in realistic settings where traits may need to be multifunctional, and historical contingencies may channel evolution to suboptimal phenotypes. Evaluating traits’ adaptive/maladaptive nature requires understanding the underlying mechanisms (the proximate causes). We studied clutch composition in a pollinating fig wasp where heterospecific females potentially interfere with sex ratio production and adjustment. Using an information-theoretic approach, we compared hypotheses and confirmed that heterospecific females disrupt Ceratosolen arabicus females’ sex ratios. Given the high fitness costs of failing to adjust optimally, we argue this maladaptation stems from rudimentary mechanisms that fail in realistic conditions and are thus forced to be multifunctional, creating fitness trade-offs. Our findings highlight how historical constraints and ecological interactions may limit adaptation, challenging the assumption that selection always produces optimal traits. Furthermore, they emphasize the need to incorporate ecological complexity when testing evolutionary predictions.
First record of the white root rot fungus Dematophora necatrix on indigenous South African trees
(Springer, 2025-05) Balocchi, Felipe; Wingfield, Michael J.; Paap, Trudy; felipe.balocchi@fabi.up.ac.za
The soilborne fungus Dematophora (=Rosellinia) necatrix and causal agent of white root rot, has a wide host range that includes many tree species of economic importance. The pathogen has a worldwide distribution, including reports from commercial orchards in South Africa since the 1970s. During tree health surveys conducted as part of a sentinel plant project, we detected the pathogen on two symptomatic individuals from the indigenous South African tree species Diospyros whyteana and Noronhia foveolata subsp. major. Observed symptoms included wilting and root rot, with characteristic white mycelium present under the bark. Dematophora necatrix was isolated from both hosts and its identity confirmed by sequencing two gene regions (ITS and actin). Pathogenicity was confirmed through inoculation tests under semi-controlled conditions by inoculating the soil with bamboo sticks colonized with the fungus. Plants of both species developed similar symptoms to those observed naturally, and the fungus was successfully recovered from all symptomatic plants. This is the first record in South Africa of D. necatrix on indigenous species and outside of commercial orchards. Given the environmental threat posed we recommend the fungus is considered for regulation in South Africa.
Medicinal chemistry progression of sapanisertib, the anticancer and dual Plasmodium phosphatidylinositol 4-kinase beta and cGMP-dependent protein kinase inhibitor, for malaria
(American Chemical Society, 2025-06) Gachuhi, Samuel; Kamunya, Stephanie; Fienberg, Stephen; Wambua, Lynn; Salomane, Nicolaas; Mayoka, Godfrey; Taylor, Dale; Coertzen, Dina; Van der Watt, Mariette Elizabeth; Reader, Janette; Birkholtz, Lyn-Marie; Wittlin, Sergio; Krugmann, Liezl; Coulson, Lauren B.; Chibale, Kelly
We recently demonstrated that the anticancer human mTOR inhibitor sapanisertib displays antimalarial activity in a malaria mouse model of infection and inhibits multiple Plasmodium kinases, including the high-value targets phosphatidylinositol 4-kinase type III beta (PI4Kβ) and cGMP-dependent protein kinase (PKG). Herein, we explore structure-activity relationships for sapanisertib analogues with benzyl and pyridyl substituents at the 7-position of the pyrazolopyrimidine core. New analogues with improved safety profiles were identified, including analogues with dual Plasmodium PI4Kβ and PKG inhibitory activity (exemplified by 19), as well as potent Plasmodium PI4Kβ inhibitors with minimal inhibitory activity against PKG (exemplified by 20). Compound 19 displayed potent antiplasmodium activity, high microsomal metabolic stability, and a good safety profile (hERG IC50 > 30; cytotoxicity selectivity index = 99). In vivo proof-of-concept, where a 4 × 50 mg kg-1 oral dose of 19 resulted in an 80% reduction in parasitemia in P. berghei-infected mice, further demonstrated the lead potential of this series. against respiratory-related infections with economic potential.
The synthesis and investigation of novel 3-benzoylbenzofurans and pyrazole derivatives for anti-HIV activity
(Royal Society of Chemistry, 2025-05) Khuzwayo, Sinothile S.; Selepe, Mamoalosi A.; Meyer, Debra; Gama, Ntombenhle Hlengiwe
Please read abstract in the article.
Microbial landscapes in Trinervitermes trinervoides termite colonies are affected by mound compartments and soil properties but not by symbiotic Podaxis fungi
(Elsevier, 2024-11-24) Bodawatta, Kasun H.; Maccario, Lorrie; Peereboom, Nils; Conlon, Benjamin H.; Li, Guangshuo; Plaszko, Tamas; Vinagre-Izquierdo, Celia; Jonsson, Knud A.; Vesala, Risto M.; De Beer, Z. Wilhelm
Termites are important ecosystem engineers and play key roles in modulating microbial communities within and outside their mounds. Microbial diversity within termite mounds is generally lower than surrounding soils, due to termite-associated antimicrobial compounds and active sanitary behaviours. Microbial symbionts of termites can also influence the microbial landscape, by inhibiting or out-competing other microbes. Certain members of the arid habitat fungal genus Podaxis (Agaricomycetes; Agaricaceae) are symbiotic with savannah specialist grass-cutting termites, and have the potential to influence mound-associated microbiomes. To test this, we characterized fungal (ITS2) and bacterial (16S rRNA) communities within and outside 49 Trinervitermes trinervoides mounds with and without Podaxis fruiting bodies across a 1000 km transect in South Africa. We predicted that Podaxis would be a dominant member of the fungal communities in mounds and negatively impact microbial diversity. Further, we explored how environmental variables shaped microbial communities, including whether soil elemental composition affected Podaxis presence. As expected, we observed less diverse fungal communities, but not bacterial communities, within than outside mounds, while microbial communities differed by sampling regions and mound compartments. Podaxis sequences were present in 48 out of 49 mounds in low relative abundances, and neither fruiting body presence nor sequence abundance were associated with microbial diversity or composition. There was, however, an overall association between the presence of Podaxis fruiting bodies and elemental composition, with different elements displaying varying associations depending on geographic region. Both environmental variables and soil elements were associated with fungal and bacterial taxa, indicating that they are key drivers of microbial community composition. Taken together, our findings suggest that microbial landscapes in termite mounds are not strongly influenced by Podaxis but mainly driven by termite filtering and regional abiotic variables and elemental compositions.
Inhibitors of malaria parasite cyclic nucleotide phosphodiesterases block asexual blood-stage development and mosquito transmission
(American Association for the Advancement of Science, 2024-10-06) Gomez-Gonzalez, Paula-Josefina; Gupta, Antima; Drought, Laura G.; Patel, Avnish; Okombo, John; Van der Watt, Mariette Elizabeth; Walker-Gray, Ryan; Schindler, Kyra A.; Burkhard, Anna Y.; Yeo, Tomas; Narwal, Sunil K.; Bloxham, Talia S.; Flueck, Christian; Walker, Eloise M.; Rey, Joshua A.; Fairhurst, Kate J.; Reader, Janette; Park, Heekuk; Pollard, Harry G.; Stewart, Lindsay B.; Brandner-Garrod, Luke; Kristan, Mojca; Sterk, Geert-Jan; Van Nuland, Youri M.; Manko, Emilia; Van Schalkwyk, Donelly A.; Zheng, Yang; Leurs, Rob; Dechering, Koen J.; Aguiar, Anna Caroline C.; Guido, Rafael V.C.; Pereira, Dhelio B.; Tumwebaze, Patrick K.; Nosbya, Samuel L.; Rosenthal, Philip J.; Cooper, Roland A.; Palmer, Mike; Parkinson, Tanya; Burrows, Jeremy N.; Uhlemann, Anne-Catrin; Birkholtz, Lyn-Marie; Small-Saunders, Jennifer L.; Duffy, James; Fidock, David A.; Brown, Alan; Gardner, Mark; Baker, David A.
Cyclic nucleotide–dependent phosphodiesterases (PDEs) play essential roles in regulating the malaria parasite life cycle, suggesting that they may be promising antimalarial drug targets. PDE inhibitors are used safely to treat a range of noninfectious human disorders. Here, we report three subseries of fast-acting and potent Plasmodium falciparum PDEβ inhibitors that block asexual blood-stage parasite development and that are also active against human clinical isolates. Two of the inhibitor subseries also have potent transmission-blocking activity by targeting PDEs expressed during sexual parasite development. In vitro drug selection experiments generated parasites with moderately reduced susceptibility to the inhibitors. Whole-genome sequencing of these parasites detected no mutations in PDEβ but rather mutations in downstream effectors: either the catalytic or regulatory subunits of cyclic adenosine monophosphate–dependent protein kinase (PKA) or in the 3-phosphoinositide-dependent protein kinase that is required for PKA activation. Several properties of these P. falciparum PDE inhibitor series make them attractive for further progression through the antimalarial drug discovery pipeline.
Metagenomic evaluation of food hygiene practices in the National School Nutrition Programme in KwaZulu Natal, South Africa
(AOSIS, 2025-06) Madlala, Sithembile S.; Mchunu, Nokuthula; Dalasile, Monica; Pierneef, Rian Ewald; Reddy, Poovendhree
BACKGROUND : The National School Nutrition Programme (NSNP) provides meals to schools in low-income areas in South Africa, implemented by the Department of Basic Education (DBE) with food safety monitored by Municipal Health Services. AIM : To assess compliance of school kitchens with general hygiene requirements (R638 of 2018) and detect food pathogens on food contact surfaces using amplified metagenomics. SETTING : The study was conducted in quintile 1 and 2 primary schools in Vryheid, KwaZulu-Natal. METHODS : A quantitative cross-sectional study assessed the safety compliance of food preparation and storage areas in 33 primary schools against national legislation standards. Fifteen samples of food contact surfaces were collected from four schools and analysed using Illumina sequencing to identify prevalent bacterial genera. RESULTS : None of the schools possessed a Certificate of Acceptability. Significant structural issues include poor pest control, inadequate sanitary facilities, a lack of food safety training and inadequate waste management. Taxonomic analysis revealed several dominant bacterial genera, including Pseudomonas, Stenotrophomonas, Acinetobacter and Pantoea, indicating potential routes for food contamination and subsequent risks for foodborne illnesses. CONCLUSION : The study highlighted critical inadequacies in food preparation and storage areas requiring urgent intervention to ensure safe meal preparation. It emphasised the need for improved food safety monitoring and compliance in schools in low-income areas. Next-generation sequencing (NGS) techniques identified a broad spectrum of pathogens, offering a robust method for assessing environmental hygiene. CONTRIBUTION : This study provides insights into food safety risks in the NSNP, informing policies and interventions to improve food safety and reduce foodborne illnesses in schools.
Avocado rhizosphere community profiling : white root rot and its impact on microbial composition
(Frontiers Media, 2025-05) Magagula, Phinda; Swart, Velushka; Fourie, Arista; Vermeulen, Alicia; Nelson, Johannes Harold; Van Rooyen, Zelda; Van den Berg, Noelani; noelani.vdberg@fabi.up.ac.za
INTRODUCTION : The avocado rhizosphere supports diverse microbial communities essential for plant health and defence against pathogens. This study aimed to investigate the impact of Dematophora necatrix, the causal agent of white root rot (WRR), on the microbial composition and soil physicochemical properties of infected and non-infected avocado trees in two South African orchards. METHODS : ITS and 16S metabarcoding was used to compare the composition and diversity of the rhizosphere microbiome. Soil physicochemical properties were also assessed, and culturable bacterial and fungal isolates from the rhizosphere were screened for antagonistic activity against D. necatrix. RESULTS : We found that D. necatrix did not significantly alter overall microbial diversity but influenced relative abundance of specific taxa. In Orchard A, dominant bacterial genera included Sphingomonas, Rokubacteriales and Lysobacter, while Orchard B featured Sphingomonas and Acidothermus while beneficial microbes such as Streptomyces and Bacillus were enriched in WRR non-infected (WRR-N) soils. The fungal profiles revealed Trichoderma and Penicillium as potential biocontrol agents enriched in WRR-N soils. Furthermore, dual-culture assays demonstrated that Bacillus, Pseudomonas, Penicillium and Trichoderma isolates inhibited D. necatrix, highlighting their biocontrol potential. Key parameters, such as soil pH and iron (Fe), correlated strongly with microbial composition, suggesting they play an important role in pathogen resilience. DISCUSSION : These findings underscore the complexity of the avocado rhizosphere and its role in managing WRR, offering a foundation for developing integrated disease management strategies to enhance avocado productivity.
Classification of Nostoc-like cyanobacteria isolated from paddy soil into Aliinostoc, Aulosira, and Desmonostoc
(Frontiers Media, 2025-05) Pham, Hang T.L.; Ngo, Trang T.; Tran, Thang V.; Duong, Tuan A.; Tran, Long D.; Tran, Anh T.T.; Nguyen, Van T.H.; Nguyen, Sang V.
Accurate identification of cyanobacterial strains is an essential step for subsequent research to be performed on these organisms. The classification of cyanobacteria in Nostocaceae remains a significant challenge due to the lack of reference data for type species and robust morphological characters for each genus. This study aims to classify 38 new isolated Nostoc–like strains at the genus level. The relationship between phylogenetic classification and morphological characteristics at the genus level was also investigated. The 16S rRNA gene sequences served as primary data for phylogenetic classification, supporting the designation of 18 isolates into the Aliinostoc, 7 isolates into the Aulosira, and 13 isolates into the Desmonostoc. Subsequently, we used these isolates as living materials to discover the most distinct features at each genus level of Aliinostoc, Aulosira, and Desmonostoc. As a result, the morphological characteristics of the three genera became distinguishable when grown in the BG110 medium. There, the mature vegetative cells of all isolated strains in the Aliinostoc were gray or brown, the strains in the Aulosira exhibited basal heterocysts at the beginning of cultivation, and the Desmonostoc strains showed the appearance of akinetes in the life cycle as an alternative reproduction. All isolated strains exhibited heterocysts, indicating their ability to fix nitrogen and potentially improve nutrient availability in paddy soil, especially in nitrogen-deficient conditions. This study provides a dataset of 16S rRNA gene sequences and morphological characteristics of Nostoc morphotypes, contributing to cyanobacterial taxonomy.
Exposure to outdoor aerospora and associated respiratory health risks among adults in Potchefstroom, North-West province, South Africa
(Frontiers Media, 2025-04) Gharbi, Dorra; Neumann, Frank Harald; Podile, Keneilwe; Mcdonald, Marinda; Linde, Jo-hanne; Frampton, Megan; Liebenberg, Jennifer Leigh; Cilliers, Sarel; Mmatladi, Tshiamo; Nkosi, Phumelele; Paledi, Keamogestswe; Piketh, Stuart; Staats, Jurgens; Burger, Roelof P.; Havenga, Henno; Garland, Rebecca M.; Bester, Petra; Lebre, Pedro Humberto
BACKGROUND : Data on allergic rhinitis and respiratory health metrics are limited for South Africa, with grass pollen as a key outdoor aeroallergen. Exotic trees such as plane trees and ragweed produce highly allergenic pollen, dominating indigenous trees and weeds. Pollen allergy prevalence data is lacking in cities of North-West province such as Potchefstroom. OBJECTIVES : This study aimed to (i) assess the prevalence of allergies to major aeroallergens, including Poaceae (grasses), Cupressus/Hesperocyparis (cypresses), Platanus (plane tree), Ulmus (elm), Quercus (oak), Betula (birch), Olea (olive), Artemisia (sagebrush), Amaranthus (amaranth), Plantago (plantain), Morus (mulberry), and Ambrosia (ragweed), along with fungal spores such as Alternaria, Cladosporium, and Penicillium/Aspergillus, and (ii) investigate the monthly incidence of major aeroallergens and reactivity levels in sensitized adults in Potchefstroom. METHODS : Skin prick tests (SPTs) were performed on 202 adults aged 18–64 years with confirmed allergic symptoms during a field campaign at North-West University (NWU)'s Potchefstroom campus. A test panel of grass, weed, tree, and fungal spore extracts previously identified via aerobiological monitoring was used. Symptom scores were recorded using ISAAC questionnaires; Spearman's statistical correlation between symptom frequency and monthly aeroallergen concentrations were analyzed. RESULTS : Among the participants, 184 (91%) exhibited positive SPT reactions: 104 (57%) are monosensitized to pollen, 45 (24%) to fungal spores, and 35 (19%) are polysensitized. Aeroallergen prevalence was higher in females (73%) than in males (27%). The most common pollen allergens were Cynodon dactylon (Bermuda grass) (85%), Zea mays (maize) (46%), Platanus spp. (plane tree) (35%), and Ulmus campestris (field elm) (33%). Among fungal spores, Alternaria was the most common (93%), followed by Cladosporium (27%). A significant and positive statistical correlation was found between allergic rhinitis symptoms and monthly pollen concentrations of Betula, Morus, Platanus, and Quercus. DISCUSSION AND CONCLUSION : This pilot study linked aeroallergens detected in Potchefstroom with allergy profiles of local residents. The findings highlight the need for more comprehensive regional studies that integrate allergen testing with aerobiological data. Raising awareness and implementing health strategies are essential for managing allergic rhinitis in South Africa. More affordable and available SPTs kits, adapted to allergy prevalence in South Africa, are strongly suggested.
Removal of organic biomass in Eucalyptus plantations has a greater impact on fungal than on bacterial networks
(Elsevier, 2025-06) Bose, Tanay; Vivas, Maria; Slippers, Bernard; Roux, Jolanda; Dovey, Steven; Kemler, Martin; Begerow, Dominik; Witfeld, Frederick; Brachmann, Andreas; Wingfield, Michael J.; Hammerbacher, Almuth; tanay.bose@fabi.up.ac.za
Complex and stable soil microbial networks are essential for productivity in plantation forestry, but their response to disturbances from harvesting and replanting is not well understood. This study assessed the impact of treatments designed to mitigate these disturbances on microbial biodiversity and networks in Eucalyptus plantation soils at three South African sites. We used high-throughput sequencing to catalogue fungal and bacterial biodiversity from 108 soil samples across three treatments: (i) retention of harvest residues (retained), (ii) removal of residues (removed), and (iii) removal of residues with added fertilizer (fertilized). Bioinformatic and statistical analyses of the sequence data revealed treatment-specific variations in microbial OTU richness, network structure and taxon associations at order-level. Microbiome richness was highest in ‘retained’ plots, and treatment-specific microbial diversity was evident in both fungal and bacterial communities. Network comparisons revealed that treatments to mitigate disturbances caused by harvesting significantly affected fungal networks but not bacterial networks. Fungal networks in ‘retained’ plots exhibited the highest complexity and stability compared to plots where the entire crop was removed. However, bacterial networks did not show significant differences in network structure among treatments. The associations between fungal and bacterial nodes were consistent in the three treatments, as indicated by similar Jaccard indices. However, distinct fungal hub nodes were found when comparing the 'retained' and 'removed' treatments. These findings highlight that retaining harvest residues enhances microbial richness and stabilizes fungal networks, making it a better strategy for managing soil disturbances than residue removal or fertilization.
Mitigation of opportunistic pathogens in hot water systems : a review focused on premise plumbing in South Africa
(Water Research Commission, 2025-05) Moodley, S.J.; Venter, S.N. (Stephanus Nicolaas); Muchesa, P.; Barnard, T.G.; Singh, A.
Water reticulation systems (i.e., premise plumbing) serve as a reservoir for opportunistic premise plumbing pathogens (OPPPs) to survive within these premise systems. OPPPs can be transmitted to individuals mainly via inhalation of aerosols from these water systems. These OPPPs can adapt, thrive and survive under a range of different conditions, which include high temperatures and low oxygen levels during stagnation, conditions often associated with household plumbing systems, including hot water systems (HWS). Hospitals are of specific concern as infections caused by OPPPs predominantly affect individuals who have underlying illnesses or health conditions. The current South African National Standard (SANS) 241 for drinking water does not provide information regarding testing for the presence of OPPPs, while the SANS 893 and 893-1 standards only provide a guideline for Legionella in water systems. The presence of OPPPs within HWS and premise plumbing is a concern, and a need exists to establish remediation and mitigation measures to control the presence of OPPPs in buildings. This review addresses risk analysis, evaluation and measures, which include the control of geyser temperatures and training of plumbers, as well as sampling and detection of OPPPs. This should limit the number of infections amongst individuals and will thus lessen the financial burden on health care systems and the economy.
Water lily pond : a multiomics database for water lilies
(Oxford University Press, 2025-06) Zhao, Chengjun; Zhang, Ji; Chen, Yayu; Yang, Lishuang; Chen, Hongliang; Liang, Yufan; Wang, Wenquan; He, Shuang; Luo, Yunqing; Zhang, Junyu; Zhang, Hongbin; Yang, Shuting; Guo, Guilian; Dai, Wenbai; Yang, Zhijuan; Chen, Junhao; Zhou, Yuhan; Khan, Wasi Ullah; Liu, Guanhua; Jiang, Yifan; Zhu, Tianlong; Xu, Yingchun; Garcia-Caparros, Pedro; Van de Peer, Yves; Xue, Jia-yu; Chen, Chengjie; Zhang, Liangsheng; Chen, Fei
No abstract available.
Oxalate content of vegetation and termite frass in western South Africa
(Wiley, 2025-05) Nel, T.; Clarke, C.E.; Francis, M.L.; Babenko, D.; Breecker, D.; Cowan, Don A.; Gallagher, T.; McAuliffe, J.R.; Trindade, M.
Please read abstract in the article.
Investigating the antimicrobial and anticancer potential of culturable fungal endophytes isolated from the stems of Kirkia acuminata Oliv
(BioMed Central, 2025-05) Magagula, Mfundo; Motaung, Thabiso Eric; Mbita, Zukile; Dithebe, Khumiso
BACKGROUND : Fungal endophytes produce various structurally and chemically diverse bioactive secondary metabolites including those that are similar to their host plants. However, fungal endophytes from South African medicinal plants are relatively under-explored. The medicinal plant, Kirkia acuminata Oliv., is on the decline in the natural environment due to overharvesting. This necessitates the search for novel alternatives to sustainably obtain the plant’s bioactive metabolites. Thus, fungal endophytes may serve as suitable candidates as they can produce host-similar bioactive compounds. RESULTS : Eighteen morphologically distinct fungal endophytes were isolated from the surface-sterilised stems of K. acuminata Oliv. Sequencing of the internal transcribed spacer (ITS) region revealed that the isolates were distributed among three genera, namely Diaporthe, Neofusicoccum and Pseudofusicoccum. The broth micro-dilution assay showed that 17 of the 18 ethyl acetate crude extracts exhibited inhibitory activity with minimum inhibitory concentration (MIC) values ranging from 0.31 to 2.5 mg/mL and 1.25 to 2.5 mg/mL against bacterial pathogens and Candida albicans, respectively. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that most of the crude extracts had dose-dependent cytotoxicity against non-cancerous human embryonic kidney (HEK-293) cells, with the crude extracts of the N. parvum KaS-3, D. macadamiae KaS-4, P. olivaceum KaS-5 and D. neotheicola KaS-6 isolates demonstrating safety against the non-cancerous cells. The alamarBlue assay revealed that the four non-cytotoxic crude extracts had moderate anticancer activity against cervical cancer ME-180 and melanoma A375 cancerous cell lines. Moreover, mycochemical analysis of the non-cytotoxic crude extracts using colourimetric quantification methods revealed that the observed cytotoxic effect could be attributed to the high total phenolic content in the crude extracts. CONCLUSION : The study highlights that the fungal endophytes inhabiting the stems of K. acuminata Oliv. produce secondary metabolites that may serve as leads for novel antimicrobial and non-toxic anticancer agents.
The root rot pathogen Phytophthora cinnamomi : a long-overlooked threat to the Cape Floristic Region of South Africa
(Springer, 2025-04) Paap, Trudy; Balocchi, Felipe; Wingfield, Michael J.; trudy.paap@fabi.up.ac.za
The globally important plant pathogen Phytophthora cinnamomi was first reported in South Africa in 1931, where it caused substantial damage to avocado orchards. Surprisingly, 40 years passed before the pathogen was recognised as a significant threat to South Africa’s natural ecosystems. This first became evident when P. cinnamomi caused a “quick decline” of the iconic silver trees (Leucadendron argenteum) in the Cape Floristic Region (CFR) of the Western Cape Province. Subsequent research has underscored the role of P. cinnamomi as a major root rot pathogen affecting numerous native species. Despite these findings, there has been limited research on the extent of the threat P. cinnamomi poses to Cape flora, leaving the risk of extinction for many species largely unknown. A recent observation of P. cinnamomi causing rapid mortality in Sorocephalus imbricatus, a Critically Endangered Proteaceae, underscores the urgent need for a comprehensive evaluation of this pathogen’s impact on Cape flora and the associated extinction risks. Given the high number of rare and threatened species in the CFR, many of which belong to families known to be vulnerable to P. cinnamomi, there is a pressing need to initiate an intensive local research programme to fill this critical gap. To address this, we propose a structured research programme that will guide targeted mitigation efforts against P. cinnamomi. Enhancing our understanding of P. cinnamomi’s threat to the CFR, a global biodiversity hotspot, will be essential to inform conservation strategies and to set restoration priorities in the region.

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