Research Articles (Paraclinical Sciences)

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Anti-biofilm and anti-quorum sensing activities of extract, fractions and compounds from the leaves of Cassia alata L. against yeast pathogens
(Elsevier, 2024-11) Dzoyem, J.P.; Fotso, Simplice Chimi; Wansi, Jean Duplex; Tabenkoueng, Bellier; Tsopgni, Willifred Dongmo Tekapi; Toze, Flavien Aristide Alfred; McGaw, Lyndy Joy; lyndy.mcgaw@up.ac.za
BACKGROUND : Cassia alata or Senna alata, also known as “ringworm bush” because of its very effective fungicidal properties, is commonly used in African traditional medicine to treat fungal infections. Despite extensive phytochemical and pharmacological studies previously reported on C. alata, the antibiofilm activity against pathogenic yeast as well as the related anti-quorum sensing mechanism of some active constituents has not yet been elucidated. The aim of the study was to isolate the bioactive constituents from the methanol extract of the leaves of C. alata (CAExt) using antibiofilm-guided fractionation against yeast fungal pathogens and then to investigate the anti-quorum sensing activity of the active constituents by assessing their ability to inhibit violacein production in Chromobacterium violaceum. METHODS : Chromatographic methods were used to isolate the constituents of CAExt, and spectroscopic methods were used to elucidate the chemical structures of the isolated compounds. The broth microdilution assay was used to evaluate the antifungal activity against Candida albicans and C. parapsilosis, while crystal violet staining was used for the inhibition of biofilm formation and the disruption of preformed biofilm. The biosensor strain C. violaceum ATCC 12472 was used to investigate the anti-quorum sensing activity of the most active constituents. RESULTS : The crude extract exhibited biofilm inhibition and eradication activities against the tested pathogenic yeast. The biofilm inhibition percentages ranged from 53.22 % to 75.38 %, while the biofilm eradication percentages ranged from 23.21 % to 64.25 %. The ethyl acetate fraction demonstrated high biofilm inhibition and eradication activities against the tested microorganisms. The biofilm inhibition percentages ranged from 58.19 % to 79.30 %, while the biofilm eradication percentages ranged from 34.105 % to 69.54 %. The purification of subfractions led to the identification of six compounds: stigmasterol (1), sitosterol (2), lupeol (3), emodin (4), kaempferol (5) and stigmasterol glycoside (6), two of which (4 and 5) showed potent biofilm inhibition and eradication activities. Both compounds demonstrated significantly lower MBIC50 values of 70.81 μg/mL and 65.65 μg/mL against Candida albicans and MBEC50 values of 63.65 μg/mL and 82.66, respectively, against C. albicans and C. parapsilosis. The crude extract and compounds (4) and (5) also demonstrated quorum sensing inhibitory activity, as indicated by the MQSIC value of 1024 μg/mL for the crude extract and 128 μg/mL for the two compounds. Moreover, compounds (4) and (5) displayed significant inhibitory effects on violacein production, as indicated by their low IC50 values of 28.08 μg/mL and 26.44 μg/mL, respectively. CONCLUSIONS : Data obtained in this study not only support the traditional use of C. alata in the treatment of fungal infections but also reveal C. alata extract, as well as the two isolated bioactive compounds emodin (4) and kaempferol (5), as a potential source for developing antibiofilm alternative agents against biofilm-associated yeast infections. LIST OF COMPOUNDS STUDIED : stigmasterol (1), sitosterol (2), lupeol (3), emodin (4), kaempferol (5), stigmasterol glycoside (6)
Does sex matter in the cheetah? Insights into the skeletal muscle of the fastest land animal
(Company of Biologists, 2024-08) Kohn, Tertius Abraham; Knobel, Samantha; Donaldson, Byron; Van Boom, Kathryn Merle; Blackhurst, Dee M.; Peart, James M.; Jensen, Jorgen; Tordiffe, Adrian Stephen Wolferstan
The cheetah is considered the fastest land animal, but studies on their skeletal muscle properties are scarce. Vastus lateralis biopsies, obtained from male and female cheetahs as well as humans, were analysed and compared for fibre type and size, and metabolism. Overall, cheetah muscle had predominantly type IIX fibres, which was confirmed by the myosin heavy chain isoform content (mean±s.d. type I: 17±8%, type IIA: 21±6%, type IIX: 62±12%), whereas humanmuscle contained predominantly type I and IIA fibres (type I: 49±14%, type IIA: 43±8%, type IIX: 7±7%). Cheetahs had smaller fibres than humans, with larger fibres in the males compared with their female counterparts. Citrate synthase (16±6 versus 28±7 μmol min−1 g−1 protein, P<0.05) and 3-hydroxyacyl co-enzyme A dehydrogenase (30±11 versus 47 ±15 μmol min−1 g−1 protein, P<0.05) activities were lower in cheetahs than in humans, whereas lactate dehydrogenase activity was 6 times higher in cheetahs (2159±827 versus 382±161 μmolmin−1 g−1 protein, P<0.001). The activities of creatine kinase (4765±1828 versus 6485 ±1298, P<0.05 μmol min−1 g−1 protein) and phosphorylase (111±29 versus 216±92 μmol min−1 g−1 protein) were higher in humans, irrespective of the higher type IIX fibres in cheetahs. Superoxide dismutase and catalase,markers of antioxidant capacity, were higher in humans, but overall antioxidant capacity was higher in cheetahs. To conclude, fibre type, fibre size andmetabolismdiffer between cheetahs and humans, with limited differences between the sexes.
Influence of tannin-rich extract from commercial Acacia mearnsii and gallocatechin on ovine cryopreserved semen viability
(Taylor and Francis, 2025) Liman, Mohammed S.; Hassen, Abubeker; Smuts, Mario P.; Biraima, Ahmed D.A.; Sutovsky, Peter; McGaw, Lyndy Joy; Holm, Dietmar Erik; dietmar.holm@up.ac.za
The objective of this study was to evaluate the effect of a tannin-rich extract from commercial Acacia mearnsii (MTE_0), and gallocatechin, a flavonoid compound derived from Acacia mearnsii, on the long-term viability and motility of cryopreserved ovine semen. Six fresh ejaculates obtained from six adult merino rams twice per week for three weeks were allocated to five aliquots (0, 12.5, 25, 50, and 100 µM gallocatechin added into the Optidyl™ extender) before cooling and cryopreservation. Effects of MTE_0 and gallocatechin on post-thawed motility characteristics were analyzed using computer-assisted semen analysis (CASA), and viability (LIVE/DEAD® kit, Molecular Invitrogen, Waltham, MA), oxidative stress (2,7-dichlorodihydrofluorescein diacetate (H2DCFDA, Thermo Fisher®, Waltham, MA)) for reactive oxygen species (ROS), mitochondrial membrane potential (JC-1 MitoTracker, Molecular Invitrogen, Waltham, MA), acrosomal integrity (lectin PNA), and capacitation using merocyanine 540 (M540) and YO-PRO-1 dyes in flow cytometry. Data were analyzed using one-way ANOVA (IBM SPSS 21.0 for Windows, Armonk, NY). Gallocatechin at 25 µM positively affected (p ≤ .001) kinematic parameters including average path velocity (VAP), progressive velocity (VSL), and beat cross frequency (BCF) of cryopreserved semen. Similarly, gallocatechin at 25 µM- improved sperm motility (live 21.99 ± 2.06%), reduced ROS levels (26.45 ± 1.10%), and mitigated premature capacitation (viable and stable 20.08 ± 1.48%) compared to other treatments. Gallocatechin addition to semen resulted in a significant (p ≤ .001) positive effect compared with the MTE_0 extract. It is concluded that gallocatechin inclusion at 25 µM significantly reduces semen deterioration following cryopreservation. This study is the first to introduce gallocatechin as an efficient antioxidant additive to ovine semen to improve its quality during storage. Our findings will help improve post-thaw ovine semen quality and longevity. Future studies to elucidate the mechanism of anti-oxidative stress action of gallocatechin and its derivatives on semen motility and longevity are recommended.
Promoting rhinoceros welfare during transit : veterinarians' perspectives on transportation practices
(Medpharm Publications, 2024-11) Macha, E.S.; Meyer, Leith Carl Rodney; Leiberich, Marion; Hofmeyr, M.; Hooijberg, Emma Henriette; emma.hooijberg@up.ac.za
Despite translocation being a useful conservation strategy in rhinoceros management, morbidities and mortalities occurring during transportation pose a significant concern to rhinoceros managers, veterinarians, and scientists. The objectives of this study were to better understand the effects of transport on rhinoceros and to gain insights from veterinarians involved in rhinoceros translocations about current practices and potential interventions that could improve welfare. A weblink and QR code to an online questionnaire with a total of 46 questions in Google Forms was sent to veterinarians who had experience in African rhinoceros transportation, through personal emails and social network forums. Results demonstrated that despite dehydration and negative energy balance being reported as the major causes of morbidities and mortalities during transport and post-release, most veterinarians (30/35; 86%) involved in rhinoceros translocation did not offer water, parenteral fluids, or feed to transported animals, for logistical reasons and the knowledge or perception of rhinoceros' resistance to taking ad lib food and water during transport. However, 52% (15/29) and 41% (15/34) of participants suggested that parenteral fluids could be used as an intervention to mitigate dehydration and negative energy balance respectively. To reduce stress, 94% (33/35) of respondents suggested the use of tranquilisers and sedatives. This study is the first to systematically investigate and report on practices by veterinarians involved in rhinoceros translocations globally. The study highlights that further research is required to explore optimal and pragmatic techniques in the field to mitigate reported welfare challenges in rhinoceros during transport.
Rol van die Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie (SATNT) in die ontginning van die natuurwetenskappe in Afrikaans die afgelope honderd jaar
(Suid Afrikaanse Akademie vir Wetenskap en Kuns, 2025-03) Eloff, Jacobus Nicolaas; kobus.eloff @up.ac.za
Die ontwikkeling van Afrikaans as wetenskapstaal is onder meer te danke aan die ondersteuning van dosente aan veral histories Afrikaanse universiteite, navorsingsrade en staatsdepartemente (byvoorbeeld die vaktaalburo). Die Suid-Afrikaanse Akademie vir Wetenskap en Kuns (SAAWK) het ’n baie belangrike rol gespeel in die ontwikkeling van vakterme en vakwoordeboeke in die natuurwetenskappe en tegnologie. In die biologiese wetenskappe het veral die Potchefstroomse Universiteit vir Christelike Onderwys (tans Noordwes-Universiteit) in vroeër jare en die Universiteit van Pretoria later ’n beduidende rol hierin gespeel. Mediese terme is aanvanklik aan die Universiteit van Stellenbosch en later ook aan die Universiteit van Pretoria ontwikkel. Afrikaanse handboeke by universiteite en skole, ondersteun deur vakwoordeboeke, het beslag gegee aan die nuutgeskepte terminologie. Tot laat in die 1980’s was baie vakverenigings in die natuurwetenskappe tweetalig en aanbiedings by kongresse kon in Afrikaans gelewer word. Met die toename aan histories Afrikaanse universiteite van studente en dosente wat nie Afrikaans kon praat of verstaan nie en die nuwe politieke bedeling ná 1994 het die meeste vakverenigings later slegs Engels gebruik. Nagraadse studente kan nog steeds in Afrikaans voordragte lewer by die studentesimposiums van die SAAWK, maar vir senior navorsers is daar nie veel meer opsies as by die jaarlikse kongresse van die SAAWK, sowel as by Akademia, die nuwe Afrikaanse tersiêre instelling, nie. Vroeër het sommige vaktydskrifte Afrikaanse manuskripte gepubliseer, maar daar is tans prakties net die Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie (SATNT) en LitNet Akademies waar Afrikaanse artikels oor die natuurwetenskappe nog gepubliseer kan word. Die SATNT publiseer al bykans 43 jaar artikels in Afrikaans, maar weens die veranderde politieke omgewing en die gepaardgaande aanpassings aan universiteite se taalbeleide is daar algaande al hoe minder artikels aangebied vir publikasie in die tydskrif. Die lewensbloed vir navorsers in die natuurwetenskappe is die sitasie van publikasies. Daar was ’n groot stryd om ook enkele publikasies in Engels in die SATNT toe te laat. ’n Oplossing is gevind deur die gedrukte kopie slegs in Afrikaans te publiseer, maar voorsiening daarvoor te maak dat Engelse artikels aanlyn ingedien en ook gekeur kan word, maar dat voordat die manuskrip aanvaar word, ’n Afrikaanse taalkundig versorgde manuskrip ingedien moet word. Hierdie benadering blyk ’n wen-wen-oplossing te wees. Om die voortbestaan van die hoër funksies in Afrikaans te bewaar, word geen bladgelde gehef nie en is daar ondersteuning vir taalversorging in Afrikaans beskikbaar deur die SAAWK. Die ontwikkeling van Akademia as Afrikaanse tersiêre instelling in die ooste van Pretoria open opwindende vooruisigte vir die behoud van Afrikaans as wetenskapstaal alhoewel Afrikaans tans steeds as erkende onderrig- en navorsingstaal by die Universiteit Stellenbosch en die Noordwes-Universiteit gebruik word.
Seasonal effects on the fecal microbial composition of wild greater thick-tailed galagos (Otolemur crassicaudatus)
(Springer, 2024-12) Long, Channen; Scheun, Juan; Sauther, Michelle Linda; Cuozzo, F.P.; Millette, James; Tordiffe, Adrian Stephen Wolferstan
Bacterial communities present in the host digestive tract are important for the breakdown and absorption of nutrients required by the host. Changes in diet and the environment are major factors affecting the composition and diversity of the fecal microbiome. In addition to changes in ambient temperature and rainfall, primates living in seasonal temperate environments also need to adapt to seasonal changes in food resource quantity and quality. However, there is a lack of information about the fecal microbiome in African strepsirrhines relative to other primate taxa. We examined the effects of seasonal dietary and environmental changes on fecal microbial alpha diversity and composition in wild greater thick-tailed galagos (Otolemur crassicaudatus) at Lajuma Research Centre, South Africa. We collected fecal samples and assessed food availability and weather in summer and winter across 1 year and used 16S rRNA next-generation sequencing to characterise the fecal microbiome of 49 animals. We found significant increases in rainfall, ambient temperature, and food availability in summer compared with winter. However, we found no significant changes in body mass or in the overall diversity of bacterial species present in fecal samples between the two seasons. We found significant decreases in the abundance of certain bacterial families in winter, suggesting a change in diet. Our findings suggest that greater thick-tailed galagos can find food resources to maintain their body mass throughout the year. Our insights into the seasonal fecal microbiome of greater thick-tailed galagos add to the growing knowledge and understanding of fecal microbiomes in primates and how they help primates cope with changes to their environments.
A review of health benefits of selected South African indigenous fruits and vegetables
(Elsevier, 2025-04) Netshiluvhi, Thiambi R.; Eloff, Jacobus Nicolaas; kobus.eloff@up.ac.za
Recent studies have indicated that South African diets from conventional food sources frequently lack balanced nutrition which has led to poor health and wellbeing of local communities. Therefore, the purpose of this review was to establish potential health benefits of indigenous fruits and vegetables to address risks of nutritional deficiencies, chronic diseases, and pathogenic infections. Google Scholar, ScienceDirect, and ResearchGate databases were used to find relevant articles from which to identify promising indigenous fruit trees and vegetables. Most fruits (Adonsonia digitata, Vangueria infausta, Parinari. curatellifolia, Strychnos species, Sclerocarya birrea, etc.) and vegetables (Solanum nigrum, Momordica foetida, Vigna subterranean, Amaranthus species, Bidens pilosa, Abelmoschus esculentus, Cucurbita species, etc.) had high concentration levels of dietary fibres, vitamins (A, B1, B2, B3, B9, C, E), and minerals (Zinc, copper, manganese, magnesium, and selenium). Some of the indigenous crops had higher concentration levels of vitamins (A, C), iron, and calcium than those of commercialised fruits or vegetables. As such, those indigenous crops could easily meet or exceed recommended daily allowances of various nutrients. The same indigenous crops also had an array of secondary metabolites such as polyphenols (phenolic acids, flavonoids, tannins, coumarins), polysaccharides, alkaloids, saponins, anthraquinones, coumarins, carotenoids, glycosides, quercetin, kaempferol, phytic acids, and linoleic acids. Dietary fibres, nutrients, and secondary metabolites exhibited antioxidant, anti-inflammatory, immunomodulatory, and antimicrobial properties, which could play a critical role in the prevention and treatment of nutrient deficiencies, chronic diseases, and pathogenic infections. The therapeutic potential of nutrients and secondary metabolites may necessitate those food plants to be classified as nutraceuticals or functional foods. Since results were mostly based on in vitro and animal-based in vivo studies, clinical tests should be undertaken to establish efficacy and safety of dietary fibres, phytonutrients, and secondary metabolites based on optimal human dosages.
Climate change and the sustainable use of medicinal plants : a call for “new” research strategies
(Frontiers Media SA, 2025-02) Mykhailenko, Olha; Jalil, Banaz; McGaw, Lyndy Joy; Echeverria, Javier; Takubessi, Marce; Heinrich, Michael
Climate change and human activities severely impact the viability of plants and ecosystems, threatening the environment, biodiversity, and the sustainable development of plant-based products. Biotic and abiotic (ecosystem) determinants affect species distribution and long-term survival, which in turn influence the quality of plants used as herbal medicines and other high-value products. In recent decades, diverse anthropogenic impacts have significantly affected these quality aspects. Climate change, excessive plant exploitation, habitat loss, species vulnerability, and other factors have adversely affected the growth, reproduction, and adaptation of species populations, as well as the quality and volume of primary plant materials supplied to pharmaceutical markets. Despite these growing challenges, there is limited knowledge of potential strategies to prevent or mitigate these impacts, particularly for vulnerable species collected from the wild or harvested from traditional production systems. Hence, effective strategies for preserving and increasing plant populations are urgently needed. In this study, we propose a new framework including the main sustainability factors to better understand and address the vulnerability of a species, hence mitigate the impact of climate change. We assess the applicability of our proposed framework via seven case studies of vulnerable species (i.e., Aquilaria malaccensis Lam., Boswellia sacra Flück., Crocus sativus L., Panax quinquefolius L., Pilocarpus microphyllus Stapf ex Wardlew., Rhodiola rosea L., and Warburgia salutaris (G.Bertol.) Chiov.) from main biogeographic realms, all widely used as medicinal plants. These species present various challenges related to the sustainability of their use, impacting their current and future status locally and globally. Their economic importance, combined with rising demands and specific risks of overexploitation, are also key factors considered here. The suggested framework for the sustainability of medicinal and other high-value plant-based products in the phytopharmaceutical industry emphasises strategies that promote conservation and sustainable resource use. It can also be adapted for other vulnerable species requiring urgent attention.
Ethnoveterinary medicines used by smallholder farmers for treatment of goat ailments in Chikomba, Murewa, Gutu and Mwenezi districts of Zimbabwe : is there cultural consensus in use practices?
(Elsevier, 2025-02) Munengwa, Anderson; Nyahangare, Emmanuel T.; Jambwa, Prosper; Mugoti, Alban; Mandara, Steven; McGaw, Lyndy Joy; lyndy.mcgaw@up.ac.za
ETHNOPHARMACOLOGICAL RELEVANCE : Zimbabwe is a key biodiversity domain in sub-Saharan Africa and ethnoveterinary medicines play an integral role in livestock health. However, knowledge on whether plants are used by only a small proportion of people or whether similar uses exist in different communities and in a more regional context is incompletely documented. AIM OF THE STUDY : Firstly, the study documented plant-based complementary medicines used for managing goat ailments. Secondly, culturally important medicinal plant species with highest use-reports (UR) as well as botanical and therapeutic consistency were computed. Thirdly, details on whether similar ethnobotanical practices exist in different communities as an indicator of information exchange were explored. MATERIALS AND METHODS : A total of 200 informants from Gutu, Chikomba, Murewa and Mwenezi districts of Zimbabwe were interviewed. Plant identification was done at the National Herbarium and Botanic Gardens of Zimbabwe. Use-reports were generated and subjected to analysis using Analysis of Variance (ANOVA) in IBM SPSS statistical software. RESULTS : The impact of parasites and diseases was ranked as the major goat production constraint. A total of 160 homemade remedies were documented, 151 of which comprised a single plant species (Homemade Single Species Herbal Remedy Reports, HSHR). The 151 HSHR prepared using 75 plant species belonging to 34 families referred to 401 UR. The foremost used medicinal plant species were from the Fabaceae family (28 HSHR, 19%). Cassia abbreviata was the most cited plant species (6 HSHR, 4%). The category of ecto- and endoparasites had the highest number of UR out of a total of 9 categories (136 UR, 34%). The most frequently used plant species for this category were Solanum campylacanthum (8 UR, 6%) and Strychnos spinosa (6 UR, 4%). Almost similar numbers of UR were computed across communities for 6 disease categories. Nine different combinations (9 HR, 9 UR) comprising mostly of three plant species were reported for various ailments. Baccharoides adoensis and Terminalia sericea were often reported in these combinations for January disease. Highest levels of therapeutic consistency were computed for Aloe vera and Lippia javanica against ectoparasites (10 out of 24 local studies). Interestingly, 28 new medicinal plant species were documented for the first time in Zimbabwe. Again, these were mostly used for ecto-and endoparasites (8 plant species, 29%). CONCLUSIONS : Ethnoveterinary medicines play a pivotal role in management of livestock ailments in rural communities of Zimbabwe. However, attention is warranted to ensure transparency in use practices, as well as to conserve and scientifically validate culturally important medicinal plant species such as Aloe vera and Lippia javanica.
Genetic characterization of diagnostic epitopes of cardiac troponin I in African rhinoceros
(Sage, 2025-03) Rautenbach, Yolandi; Parsons, Sven David Charles; Loots, Angelika Katrin; Goddard, Amelia; Meyer, Leith Carl Rodney; Buss, Peter Erik; Hooijberg, Emma Henriette
African rhinoceros undergo chemical immobilization and prolonged transport during translocations for conservation purposes and, hence, experience several pathophysiologic changes, including skeletal muscle injury. Potential concurrent myocardial injury has not been investigated due to a lack of validated immunoassays. We aimed to use inferred cardiac troponin I (cTnI) amino acid sequences of southern white (Ceratotherium simum simum) and southern-central black (Diceros bicornis minor) rhinoceros to assess the potential usefulness of several commercial cTnI immunoassays for detecting cTnI in African rhinoceros. We extracted RNA from the myocardium of deceased rhinoceros (2 white, 1 black rhinoceros) followed by primer design, cDNA synthesis via RT-PCR, and Sanger sequencing. The inferred cTnI amino acid sequences were obtained from the mRNA transcript sequences. The homology of epitope binding sites recognized by capture and detection antibodies in 6 human immunoassays was visually evaluated using aligned inferred rhinoceros cTnI amino acid sequences. Percentage identity between white and black rhinoceros cDNA nucleotide sequences was 99%; inferred amino acid sequences were identical. There were 5 amino acid differences between humans and rhinoceros in the epitope binding sites of immunoassay antibodies; 5 assays contained antibodies against epitopes that were not conserved. For one assay, the single capture antibody targeted a short heterologous epitope (residue 87–91), and cross-reactivity with rhinoceros cTnI was deemed unlikely. For the other 5 assays, complete antibody-epitope homology, or the inclusion of multiple detection or capture antibodies, or targeting of long epitopes, indicated that these assays could be suitable for further investigation of cTnI measurement in African rhinoceros.
Taenia saginata prevalence in cattle slaughtered at low throughput abattoirs in South Africa
(AOSIS, 2024-12-04) Dube, Mbali P.; Byaruhanga, Charles; Dorny, P.; Dermauw, Veronique; Qekwana, Daniel Nenene
Meat inspection is the routine method used to identify cattle infected with Taenia saginata; however, the sensitivity of this method is low. We investigated the prevalence of T. saginata infection in cattle slaughtered in low throughput abattoirs (LTs) in Gauteng province, South Africa, based on meat inspection and serology. A total of 188 cattle carcasses from three abattoirs underwent meat inspection for the presence of T. saginata cysticerci, while serum wastested for the occurrence of antigens using antigen enzyme-linked immuno sorbent assay (Ag-ELISA). Polymerase chain reaction (PCR)-sequencing was performed to confirm T. saginata cysts identified during enhanced inspection and incision of 10 randomly selected hearts. Apparent and true prevalence were calculated, and a logistic regression model was fit to evaluate associations between abattoir, sex, animal origin, age and T. saginata serological status. Out of the 188 carcasses, no positive cases (0%) were identified during routine meat inspection, yet three cysticerci-like lesions were identified from three hearts following additional incisions, of which one was confirmed as T. saginata. Fifty-four of the sampled cattle carcasses tested positive using Ag-ELISA (apparent and true prevalence: 29.0%, 71.8%). Feedlot cattle were less likely (odds ratios [OR]: 0.33, p = 0.043) to have a positive serological test result for T. saginata compared to non-feedlot cattle, and the odds of a positive result differed between abattoirs (p < 0.05). CONTRIBUTION: Our results confirmed the low sensitivity of routine meat inspection in LTs, which may pose a public health risk, and therefore other diagnostic methods need to be included in the surveillance system for T. saginata.
Clinical Coxiella burnetii infection in sable and roan antelope in South Africa
(AOSIS, 2024-07-26) Wiedeman, Wikus; Glover, Akorfa B.; Steyl, Johan Christian Abraham; O'Dell, Jacques Henry; Van Heerden, Henriette; henriette.vanheerden@up.ac.za
Various zoonotic microorganisms cause reproductive problems such as abortions and stillbirths, leading to economic losses on farms, particularly within livestock. In South Africa, bovine brucellosis is endemic in cattle, and from 2013–2018, outbreaks of Brucella melitensis occurred in sable. Coxiella burnetii, the agent responsible for the zoonotic disease known as Q-fever and/or coxiellosis, also causes reproductive problems and infects multiple domestic animal species worldwide, including humans. However, little is known of this disease in wildlife. With the expansion of the wildlife industry in South Africa, diseases like brucellosis and coxiellosis can significantly impact herd breeding success because of challenges in identifying, managing and treating diseases in wildlife populations. This study investigated samples obtained from aborted sable and roan antelope, initially suspected to be brucellosis, from game farms in South Africa using serology tests and ruminant VetMAX™ polymerase chain reaction (PCR) abortion kit. The presence of C. burnetii was confirmed with PCR in a sable abortion case, while samples from both sable and roan were seropositive for C. burnetii indirect enzyme-linked immunosorbent assay (iELISA). This study represents the initial report of C. burnetii infection in sable and roan antelope in South Africa. Epidemiological investigations are crucial to assess the risk of C. burnetii in sable and roan populations, as well as wildlife and livestock in general, across South Africa. This is important in intensive farming practices, particularly as Q-fever, being a zoonotic disease, poses a particular threat to the health of veterinarians and farm workers as well as domestic animals.
Ultrastructural changes in cardiac and skeletal myoblasts following in vitro exposure to monensin, salinomycin, and lasalocid.
(Public Library of Science, 2024-09-25) Henn, Danielle; LensinkI, Antonia V.; Botha, C.J. (Christoffel Jacobus); antoinette.lensink@up.ac.za
Carboxylic ionophores are polyether antibiotics used in production animals as feed additives, with a wide range of benefits. However, ionophore toxicosis often occurs as a result of food mixing errors or extra-label use and primarily targets the cardiac and skeletal muscles of livestock. The ultrastructural changes induced by 48 hours of exposure to 0.1 μM monensin, salinomycin, and lasalocid in cardiac (H9c2) and skeletal (L6) myoblasts in vitro were investigated using transmission electron microscopy and scanning electron microscopy. Ionophore exposure resulted in condensed mitochondria, dilated Golgi apparatus, and cytoplasmic vacuolization which appeared as indentations on the myoblast surface. Ultrastructurally, it appears that both apoptotic and necrotic myoblasts were present after exposure to the ionophores. Apoptotic myoblasts contained condensed chromatin and apoptotic bodies budding from their surface. Necrotic myoblasts had disrupted plasma membranes and damaged cytoplasmic organelles. Of the three ionophores, monensin induced the most alterations in myoblasts of both cell lines.
Hepatoprotective effects of leaf extract of Annona senegalensis against aflatoxin B1 toxicity in rats
(AOSIS, 2024-03-11) Makhuvele, Rhulani; Foubert, Kenn; Hermans, Nina; Pieters, Luc; Verschaeve, Luc; Elgorashi, Esam E.
Global aflatoxin contamination of agricultural commodities is of the most concern in food safety and quality. This study investigated the hepatoprotective effect of 80% methanolic leaf extract of Annona senegalensis against aflatoxin B1 (AFB1)-induced toxicity in rats. A. senegalensis has shown to inhibit genotoxicity of aflatoxin B1 in vitro. The rats were divided into six groups including untreated control, aflatoxin B1 only (negative control); curcumin (positive control; 10 mg/kg); and three groups receiving different doses (100 mg/kg, 200 mg/kg, and 300 mg/kg) of A. senegalensis extract. The rats received treatment (with the exception of untreated group) for 7 days prior to intoxication with aflatoxin B1. Serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, and creatinine were measured. Hepatic tissues were analysed for histological alterations. Administration of A. senegalensis extract demonstrated hepatoprotective effects against aflatoxin B1-induced toxicity in vivo by significantly reducing the level of serum aspartate aminotransferase and alanine aminotransferase and regenerating the hepatocytes. No significant changes were observed in the levels of alkaline phosphatase, lactate dehydrogenase, and creatinine for the AFB1 intoxicated group, curcumin+AFB1 and Annona senegalensis leaf extract (ASLE)+AFB1 (100 mg/kg, 200 mg/kg, and 300 mg/kg body weight [b.w.]) treated groups. Annona senegalensis is a good candidate for hepatoprotective agents and thus its use in traditional medicine may at least in part be justified. CONTRIBUTION : The plant extract investigated in this study can be used in animal health to protect the organism from toxicity caused by mycotoxins.
Antimicrobial resistance of Staphylococcus spp. from human specimens submitted to diagnostic laboratories in South Africa, 2012–2017
(MDPI, 2024-09-09) Sigudu, Themba Titus; Oguttu, James Wabwire; Qekwana, Daniel N.; nenene.qekwana@up.ac.za
Antimicrobial resistance (AMR) poses a significant worldwide health challenge associated with prolonged illnesses, increased healthcare costs, and high mortality rates. The present study examined the patterns and predictors of AMR among human Staphylococcus isolates obtained from diagnostic laboratories in South Africa between 2012 and 2017. This study examined data from 404 217 isolates, assessing resistance rates across different characteristics such as age, sample origin, Staphylococcus species, and study period. The highest resistance was observed against cloxacillin (70.3%), while the lowest resistance was against Colistin (0.1%). A significant (p < 0.05) decreasing trend in AMR was observed over the study period, while a significant increasing temporal trend (p < 0.05) was observed for multidrug resistance (MDR) over the same period. A significant (p < 0.05) association was observed between specimen type, species of organism, and year of isolation with AMR outcome. Significant (p < 0.05) associations were observed between specimen type and season with MDR. The observed high levels of AMR and a growing trend in MDR are concerning for public health. Clinicians should take these findings into account when deciding on therapeutic options. Continued monitoring of AMR among Staphylococcus spp. and judicious use of antimicrobials in human medicine should be promoted.
Correlation between aerosol particulates, carcass dirtiness, and hygiene indicators of bovine carcasses in the abattoir environment : results of a study in Italy
(MDPI, 2024-06) Cenci-Goga, Beniamino T.; Tedeschini, Emma; Costanzi, Egidia; Maranesi, Margherita; Karama, Musafiri; El-Ashram, Saeed; Saraiva, Cristina; Garcia-Diez, Juan; Zerani, Massimo; Al-Olayan, Ebtesam M.; Grispoldi, Luca; musafiri.karama@up.ac.za
The objective of this study was to demonstrate the possible correlation of visible carcass contamination and abattoir aerosol quality with microbial hygiene criteria. A total of 279 bovine carcasses were analyzed on 23 different working days. The aerobic colony count and total coliforms on the carcasses were calculated together with the presence of Escherichia coli. To determine the visible contamination of carcasses, we used a 100 cm2 sheet of transparent, adhesive plastic material, applied to the side of the carcass, to collect all the particles, which were then counted against both black and white backgrounds. The daily particulate index in the abattoir aerosol was determined using an air sampler device. The results showed that aerobic colony counts, which ranged from 1.41 to 2.40 log cfu cm−2, total coliforms (from 0.00 to 0.73 log cfu cm−2), and E. coli presence (from 0.00% to 60% of the sampled carcasses per day) are not correlated with the carcasses’ visual dirtiness or the aerosol quality. The factor analysis showed a correlation between the three groups of variables investigated: group 1, representing “aerosol quality”, group 2, representing the “microbiology of the carcass”, and group 3, the “visual dirtiness of the carcass”. Thus, even though microbiology analysis is useful in diagnosing the microorganisms which the official veterinarian is unable to detect during the post-mortem inspection, it is ineffective in evaluating slaughtering procedures. Aerosol monitoring and the visual classification of carcass dirtiness, instead, could provide good indications of the slaughtering process and the quality of the abattoir environment, and guarantee control of manufacturing practices, protecting both animals’ and operators’ health.
Case report : discovery of tuberculosis caused by Mycobacterium bovis in free-ranging vervet monkeys in the Greater Kruger Conservation Area
(Frontiers Media, 2024-12) De Klerk-Lorist, Lin-Mari; Miller, Michele A.; Mitchell, Emily P.; Lorist, Rudolf; Van Dyk, David Schalk; Mathebula, Nomkhosi; Goosen, Louise; Dwyer-Leonard, Rebecca; Ghielmetti, Giovanni; Streicher, Elizabeth M.; Kerr, Tanya J.
Animal tuberculosis (TB) has been reported in several wildlife species in the Greater Kruger Conservation Area (GKCA), South Africa. This report describes the discovery of clinical tuberculosis, caused by Mycobacterium bovis (M. bovis), in free-ranging vervet monkeys (Chlorocebus pygerythrus). The “One Health” concept is especially relevant to TB since this is a multi-host disease with zoonotic potential and is endemic in GKCA. Vervet monkeys have become habituated to humans in tourist areas and may be a source of infection through close contact. Indirect transmission of M. bovis through environmental sources has also been suspected to present a risk of spread between host species. Clinically diseased monkeys present in two tourist areas in the GKCA, that died (n = 1) or were euthanized (n = 5), were submitted for diagnostic necropsies. The presence of pathological lesions, Ziehl-Neelsen-stained impression smears, Xpert® MTB/RIF Ultra (GXU) assay, mycobacterial culture and speciation by genomic regions of difference PCR, were used to confirm the diagnosis of M. bovis infection in these monkeys. The finding of multiple cases necessitates further investigation of TB in monkey troops living within the GKCA tourist areas to determine the source of infection and assess the risk of transmission to other animals and humans.
Draft genome sequences of three poultry Salmonella Shamba isolates from South Africa
(American Society for Microbiology, 2024-09) Karama, Musafiri; Lawal, Opeyemi U.; Parreira, Valeria R.; Soni, Mitra; Chen, Yanhong; Cenci-Goga, Beniamino T.; Grispoldi, Luca; Greyling, Janita; Goodridge, Lawrence; musafiri.karama@up.ac.za
Nontyphoidal Salmonella enterica serovars are foodborne pathogens commonly transmitted through poultry products. Draft genome sequences of three Salmonella enterica subsp. enterica serovar Shamba isolates which were obtained from poultry house dust in South Africa are reported herein.
Draft genome sequences of two Salmonella Uzaramo isolates from poultry in South Africa
(American Society for Microbiology, 2024-01) Karama, Musafiri; Lawal, Ismaheel O.; Parreira, Valeria R.; Soni, Mitra; Chen, Yanhong; Cenci-Goga, Beniamino T.; Grispoldi, Luca; Greyling, Anita; Goodridge, Lawrence; musafiri.karama@up.ac.za
Salmonella enterica is a zoonotic pathogen and a leading cause of foodborne gastroenteritis in humans. Here, we report the draft genome sequences of two Salmonella Uzaramo isolates, which were isolated from poultry organs during routine post-mortem examination in South Africa. Currently, whole-genome sequences on Salmonella Uzaramo are scanty.
Wastewater and environmental sampling holds potential for antimicrobial resistance surveillance in food-producing animals - a pilot study in South African abattoirs
(Frontiers Media, 2024-10) Heljanko, Viivi; Karama, Musafiri; Kymäläinen, Amanda; Kurittu, Paula; Johansson, Venla; Tiwari, Ananda; Nyirenda, Matteo; Malahlela, Mogaugedi N.; Heikinheimo, Annamari
Antimicrobial resistance (AMR) poses a significant global One Health challenge that causes increased mortality and a high financial burden. Animal production contributes to AMR, as more than half of antimicrobials are used in food-producing animals globally. There is a growing body of literature on AMR in food-producing animals in African countries, but the surveillance practices across countries vary considerably. This pilot study aims to explore the potential of wastewater and environmental surveillance (WES) of AMR and its extension to the veterinary field. Floor drainage swab (n = 18, 3/abattoir) and wastewater (n = 16, 2-3/abattoir) samples were collected from six South African abattoirs that handle various animal species, including cattle, sheep, pig, and poultry. The samples were tested for Extended-Spectrum Beta-Lactamase (ESBL) and Carbapenemase-producing Enterobacterales, Methicillin-Resistant Staphylococcus aureus (MRSA), Vancomycinresistant Enterococci (VRE), and Candida auris by using selective culturing and MALDI-TOF MS identification. The phenotype of all presumptive ESBL-producing Escherichia coli (n = 60) and Klebsiella pneumoniae (n = 24) isolates was confirmed with a disk diffusion test, and a subset (15 and 6 isolates, respectively), were further characterized by whole-genome sequencing. In total, 314 isolates (0–12 isolates/sample) withstood MALDI-TOF MS, from which 37 species were identified, E. coli and K. pneumoniae among the most abundant. Most E. coli (n = 48/60; 80%) and all K. pneumoniae isolates were recovered from the floor drainage samples, while 21 presumptive carbapenem-resistant Acinetobacter spp. isolates were isolated equally from floor drainage and wastewater samples. MRSA, VRE, or C. auris were not found. All characterized E. coli and K. pneumoniae isolates represented ESBL-phenotype. Genomic analyses revealed multiple sequence types (ST) of E. coli (n = 10) and K. pneumoniae (n = 5), including STs associated with food-producing animals globally, such as E. coli ST48 and ST10 and K. pneumoniae ST101. Common beta-lactamases linked to food-producing animals, such as blaCTX-M-55 and blaCTX-M-15, were detected. The presence of food-production animal-associated ESBL-gene-carrying E. coli and K. pneumoniae in an abattoir environment and wastewater indicates the potential of WES in the surveillance of AMR in food-producing animals. Furthermore, the results of this pilot study encourage studying the topic further with refined methodologies.

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