Department of Medical BioSciences

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https://hdl.handle.net/10566/76

The department fields specific expertise within the broad research fields of Anatomy, Cardiovascular Physiology, Herbal Sciences, Immunology, Medical Microbiology, Molecular & Cell Biology, Neuroscience, Reproduction, Toxicology and Virology

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Accuracy of magnetic resonance imaging in detecting lumbo-sacral nerve root compromise: A systematic literature review
(BioMed Central, 2016) Tawa, Nassib; Rhoda, Anthea; Diener, Ina
Background: MRI is considered to be the diagnostic tool of choice in diagnosing nerve root compromise among patients presenting with clinical suspicion of lumbo-sacral radiculopathy. There exists controversy among researchers and clinicians regarding the diagnostic utility and accuracy of MRI in detecting nerve root compromise and radiculopathy. This review evaluated 4 primary diagnostic accuracy studies that specifically assessed the accuracy of MRI in detecting nerve root compromise, as established in the current literature. Methods: Eight electronic data bases were searched for relevant articles from inception until January 2014. All primary diagnostic studies which investigated the accuracy of MRI in diagnosing nerve root compromise among patients with low back and referred leg symptoms were screened for inclusion. Qualifying studies were retrieved and independently assessed for methodological quality using the 'Quality Assessment of Diagnostic tests Accuracy Studies' criteria. Results: Four studies qualified for inclusion in this review. The sensitivity of MRI in detecting lumbar nerve root compromise was very low at 0.25 (95 % CI) while the specificity was relatively high at 0.92 (95 % CI). Conclusions: There is lack of sufficient high quality scientific evidence in support or against the use of MRI in diagnosing nerve root compression and radiculopathy. Therefore, clinicians should always correlate the findings of MRI with the patients' medical history and clinical presentation in clinical decision making.
Accurate automated quantitative imaging of tortoise erythrocytes using the NIS image analysis system
(Taylor & Francis, 2013) Walton, S.; Hofmeyr, Margaretha D.; van der Horst, Gerhard
The standard method for assessing blood cell characteristics using an ocular micrometer is time-consuming and limited. We used the Nikon NIS Elements imaging software and May-Grünwald-Giemsa staining to determine whether automated image analysis is suitable for rapid and accurate quantitative morphometry of erythrocytes. Blood was collected during four seasons from 126 geometric tortoises and the blood smears were evaluated for cell (C) and nuclear (N) characteristics of the erythrocytes. We measured area, length (L), width (W), perimeter, elongation and pixelation intensity, and calculated L/W and N/C areas. Erythrocyte size differed among cohorts; females, the larger sex, had smaller erythrocytes than either males or juveniles. Males had more elongated erythrocytes than females and erythrocytes of adults were more elongated than those of juveniles. Erythrocyte size and shape influence the efficiency of gas exchange owing to surface area to volume ratios, which are greater for small, elongated cells than for large, round cells. The high N/C ratio and low pixelation intensities of males and juveniles indicate that they may have had more immature erythrocytes in their circulation than females. The use of pixelation intensity to indicate the presence of immature erythrocytes was validated by seasonal differences that corresponded to the biology of the tortoises. Pixelation intensity was lowest in winter. We found that automated image analysis is a rapid and reliable method for determining cell size and shape, and it offers the potential for distinguishing among developmental stages that differ in staining intensity. The method should be useful for rapid health assessments, particularly of threatened species, and for comparative studies among different vertebrates.
Acute toxicity studies of the South African medicinal plant Galenia africana
(Elsevier, 2018) Ng’uni, Tiza; Klaasen, Jeremy A.; Fielding, Burtram C.
Background: Medicinal plants are used by a large proportion of the global population as complementary and alternative medicines. However, little is known about their toxicity. G. africana has been used to treat wounds, coughs and skin diseases and is used in cosmetic formulations such as lotions and shampoos. Methods: The acute oral and dermal toxicity potential of G. africana was analyzed after a single administration of 300 and 2000 mg/kgbw for acute oral toxicity and 2000 mg/kgbw for acute dermal toxicity. Female Sprague- Dawley rats were used for the acute oral toxicity study whereas both male and female Sprague-Dawley rats were used for the acute dermal toxicity study. In the Episkin skin irritation test, the irritation potential of G. africana (concentrate) and G. africana (in-use dilution) extracts were assessed using the Episkin reconstituted human epidermis. In the dermal sensitization study, female CBA/Ca mice were treated with G. africana concentrations of 50, 100 and 200 mg/ml respectively. The vehicle of choice was dimethylformamide which acted as a control. Results: The results of the acute oral and dermal toxicity studies revealed that the median lethal dosage (LD50) for G. africana extract in Sprague-Dawley rats was considered to exceed 2000 mg/kgbw. In the irritation test, the G. africana (concentrate) and G. africana (in-use dilution) extracts were non-irritant on the Episkin reconstituted human epidermis. In the dermal sensitization study, the stimulation index (SI) values for the mice treated with the G. africana extract at concentrations of 50, 100 and 200 mg/ml/kgbw, when compared to the control group, were 1.3, 0.9 and 1.3 respectively. The open application of the extract at the various concentrations did not result in a SI of ≥ 3 in any group. Hence, it did not elicit a hypersensitivity response. Conclusion: These findings demonstrate that the acute toxicity profile for G. africana is acceptable and can subsequently be used for single use in the pharmaceutical and cosmetic industries.
Additive antibacterial activity of naringenin and antibiotic combinations against multidrug resistant Staphylococcus aureus
(Academic Journals, 2015) Ng'uni, Tiza; Mothlalamme, Thato; Daniels, Raymond; Klaasen, Jeremy; Fielding, Burtram C.
Methicillin-resistant Staphylococcus aureus has been causing numerous problems in the health care sector. This is mainly due to its ability to develop resistance to a number of antibiotics used to treat staphylococcal infections. Medicinal plants have been used to treat various ailments over the years and are generating a lot of interest as alternative treatment options. Naringenin is a plant derived flavonoid that possesses antibacterial properties, among others. This study assessed the effect of combinations of naringenin and four antibiotics against two Staphylococcus aureus strains. The minimum inhibitory concentrations were determined using the disk diffusion and broth microdilution assays. In the disk diffusion assay, naringenin did not inhibit bacterial growth, nor did it enhance the antibacterial activity of the antibiotics in the combination study. This was attributed to its slow rate of diffusion out of the disks. On the contrary, in the broth microdilution assay, naringenin exhibited additive effects when combined with the antibiotics (at sub-inhibitory concentrations). These results show the potential of naringenin as an antibacterial agent. Furthermore, the additive effects observed at low naringenin concentrations showed that it can potentially be used in combination with antibiotics against multidrug resistant bacteria.
Agent in urgent need of clinical practice: corilagin
(Bentham Science Publishers, 2023) Wang, Xuejia; Fisher, David; Pronyuk, Khrystyna
Corilagin is a naturally occurring water-soluble retrogallic acid tannin, which can be ex-tracted from many kinds of plants. Known at present, it is the main effective ingredient of Phyllanthus urinaria L., Geranium wilfordii Maxim., Phyllanthus matsumurae Hayata, and Trifolium repens L. It also exists in Phyllanthus emblica L., Dimocarpus longan Lour., Canarium album (Lour.) Raeusch., and Terminalia chebula Retz. It can participate in a variety of signaling pathways in vivo and has multiple biological activities, including antitumor, anti-microbial, anti-oxidation, anti-inflammation, hepa-toprotective, anti-allergy, anti-proliferation and so on. Given the limited efficacy of first-line treatments for many diseases such as oncology, chronic liver disease, and rheumatic immune system dis-eases, and the potential for adverse effects to outweigh the therapeutic effects, attention is being fo-cused on alternative treatments, and natural plant extracts are a natural target for alternative treat-ments, as natural substances tend to have low toxicity to normal tissues. Some proprietary Chinese medicines containing corilagin have been used in clinical applications, being clinically applied to treat chronic liver disease, viral hepatitis B, rheumatoid arthritis and other diseases. This paper reviews the extraction, determination, distribution and harvesting, pharmacokinetics, biological activity, safety assessment of corilagin and its application in clinical practice.
Aggregatibacter actinomycetemcomitans serotypes in gingival crevicular fluid of mothers delivering preterm.
(University of the Western Cape, 2024) Messeir, Ilze
Preterm birth (PTB), defined as delivery before 37 weeks of gestation, is a significant global public health concern. It has a tremendous impact on both the healthcare system and the individual families affected. Low birth weight (LBW), is a direct consequence of PTB or intrauterine growth restriction, and is a major determinant of neonatal infant morbidity and mortality. The primary aim of this study was to determine if the prevalence of Aggregatibacter actinomycetemcomitans (Aa) serotypes in gingival crevicular fluid (GCF) stored for more than ten years could be used as microbial biomarkers to predict preterm delivery. The study samples included 185 samples from “preterm birth” and “normal birth” mothers with pregnancy gingivitis.
Alkaloids: Therapeutic Potential against Human Coronaviruses
(MPDI, 2020) Fielding, Burtram Clinton; da Silva Maia Bezerra Filho, Carlos; Ismail, Nasser S.M.
Alkaloids are a class of natural products known to have wide pharmacological activity and have great potential for the development of new drugs to treat a wide array of pathologies. Some alkaloids have antiviral activity and/or have been used as prototypes in the development of synthetic antiviral drugs. In this study, eleven anti-coronavirus alkaloids were identified from the scientific literature and their potential therapeutic value against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is discussed. In this study, in silico studies showed an affinity of the alkaloids for binding to the receptor-binding domain of the SARS-CoV-2 spike protein, putatively preventing it from binding to the host cell. Lastly, several mechanisms for the known anti-coronavirus activity of alkaloids were discussed, showing that the alkaloids are interesting compounds with potential use as bioactive agents against SARS-CoV-2.
Aloe ferox, Agathosma betulina, and Bulbine frutescens extracts show antifungal activity at concentrations favourable to the proliferation of epidermal cells
(Elsevier GmbH, 2025) Ndlovu, Banele; Klaasen, Jeremy; Abrantes, Pedro; Africa, Charlene; Fisher (née Rahiman), Farzana
Introduction: The increasing prevalence of antifungal resistance presents an enormous challenge to healthcare professionals. The adverse effects and resistance of current antifungal drugs have prompted the need for alternate antifungal therapy in the form of natural products. Although anecdotal reports have suggested that Aloe ferox, Agathosma betulina, and Bulbine frutescens have been used to successfully treat fungal skin infections, little scientific evidence is available to validate these claims. Therefore, this study aimed to determine whether the concentrations of A ferox, A betulina, and B frutescens hydroethanolic extracts showing antifungal activity against skin-related Candida species are cytotoxic to normal human epidermal cells. Methods: Crystal violet and lactate dehydrogenase assays were employed to determine cell viability and cytotoxicity on the human epidermal cells. Broth microdilutions were performed to evaluate the susceptibility of Candida species to plant extracts. Results: Candida spp. inhibition was observed at a concentration of 200 µg/ml, while optimum extract concentrations for cell proliferation ranged between 200 and 400 µg/ml for B frutescens and 200 µg/ml for A ferox and A betulina. This suggests that these plants could prove to be effective as antifungal agents at a dosage of 200 µg/ml while still supporting the growth of epidermal cells at the same concentration, which is an important process in maintaining healthy skin. Conclusions: These findings from this study lay a foundation for further studies confirming the applicability of these medicinal plants as safe alternative antifungal treatments that promote skin cell proliferation, regeneration, and enhance tissue repair.
Alternative medicine and herbal remedies in the treatment of erectile dysfunction: A systematic review
(Informa UK Limited, trading as Taylor & Francis Group., 2021) Leisegang, Kristian; Finelli, Renata
Objectives: To systematically review and discuss the current evidence from placebo-controlled clinical trials that investigated the use of alternative medicines and herbal remedies in the management of erectile dysfunction (ED). Methods: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)- based systematic review using specific keyword combinations was conducted on the PubMed and Scopus databases. Randomised controlled trials investigating herbal medicine in at least one group and using the International Index of Erectile Function (IIEF) as an outcome in patients primarily diagnosed with ED were included for review. Results: Following the literature search, screening and eligibility analysis, a total of 42 articles were included. The 42 articles were categorised as single herb extractions (n = 14), combination herbal formula (n = 5), combination of herbal formula and non-herbal nutraceuticals (n = 7), non-herbal nutraceuticals (n = 5), acupuncture and moxibustion (n = 2), diet and nutrition (n = 3), exercise (n = 5), and topical treatments (n = 1). Based on the results, Korean ginseng, Pygnogenol and Prelox, Tribulus terrestris, Lepidium meyenii, L-arginine, acupuncture and lifestyle interventions were the more predominantly investigated treatments interventions for ED. Conclusions: Panax ginseng, Pygnogenol, Prelox and Tribulus terrestris have promising evidence as herbal products, alongside L-arginine as a nutritional supplement, for ED based on IIEF outcomes, and warrant further clinical investigation. The mechanisms of action remain unclear, but each of these appears to in part increase nitric oxide synthesis. Importantly, improved diet and exercise should be considered, particularly in patients with obesity or diabetes mellitus.
Amino acids 1055 to 1192 in the S2 Region of severe acute respiratory syndrome Coronavirus S Protein induce neutralizing antibodies: Implications for the development of vaccines and antiviral agents
(American Society for Microbiology, 2005) Keng, Choong-Tat; Zhang, Aihua; Shen, Shuo; Lip, Kuo-Ming; Fielding, Burtram C.; Tan, Timothy H.P.; Chou, Chih-Fong; Loh, Chay Boon; Wang, Sifang; Fu, Jianlin; Yang, Xiaoming; Lim, Seng Gee; Hong, Wanjin; Tan, Yee-Joo
The spike (S) protein of the severe acute respiratory syndrome coronavirus (SARS-CoV) interacts with cellular receptors to mediate membrane fusion, allowing viral entry into host cells; hence it is recognized as the primary target of neutralizing antibodies, and therefore knowledge of antigenic determinants that can elicit neutralizing antibodies could be beneficial for the development of a protective vaccine. Here, we expressed five different fragments of S, covering the entire ectodomain (amino acids 48 to 1192), as glutathione S-transferase fusion proteins in Escherichia coli and used the purified proteins to raise antibodies in rabbits. By Western blot analysis and immunoprecipitation experiments, we showed that all the antibodies are specific and highly sensitive to both the native and denatured forms of the full-length S protein expressed in virus-infected cells and transfected cells, respectively. Indirect immunofluorescence performed on fixed but unpermeabilized cells showed that these antibodies can recognize the mature form of S on the cell surface. All the antibodies were also able to detect the maturation of the 200-kDa form of S to the 210-kDa form by pulse-chase experiments. When the antibodies were tested for their ability to inhibit SARS-CoV propagation in Vero E6 culture, it was found that the anti-S 10 antibody, which was targeted to amino acid residues 1029 to 1192 of S, which include heptad repeat 2, has strong neutralizing activities, suggesting that this region of S carries neutralizing epitopes and is very important for virus entry into cells.
An evaluation of the potential radiosensitization effect of spherical gold nanoparticles to induce cellular damage using different radiation qualities
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Engelbrecht-Roberts, Monique; de Kock, Maryna; Miles, Xanthene
Global disparities in cancer prevention, detection, and treatment demand a unified international effort to reduce the disease’s burden and improve outcomes. Despite advances in chemotherapy and radiotherapy, many tumors remain resistant to these treatments. Gold nanoparticles (AuNPs) have shown promise as radiosensitizers, enhancing the effectiveness of low-energy X-rays by emitting Auger electrons that cause localized cellular damage. In this study, spherical AuNPs of 5 nm and 10 nm were characterized and tested on various cell lines, including malignant breast cells (MCF-7), non-malignant cells (CHO-K1 and MCF-10A), and human lymphocytes. Cells were treated with AuNPs and irradiated with attenuated 6 megavoltage (MV) X-rays or p(66)/Be neutron radiation to assess DNA double-strand break (DSB) damage, cell viability, and cell cycle progression. The combination of AuNPs and neutron radiation induced higher levels of γ-H2AX foci and micronucleus formation compared to treatments with AuNPs or X-ray radiation alone. AuNPs alone reduced cellular kinetics and increased the accumulation of cells in the G2/M phase, suggesting a block of cell cycle progression. For cell proliferation, significant effects were only observed at the concentration of 50 μg/mL of AuNPs, while lower concentrations had no inhibitory effect. Further research is needed to quantify internalized AuNPs and correlate their concentration with the observed cellular effects to unravel the biological mechanisms of their radioenhancement.
An outbreak of measles in Iraq
(University of Anbar, 2024) Al-Ani, Raid; Abdul-Rasool, Sahar
Measles is a highly contagious illness which can be prevented by a vaccine. It needs to be interrupted from transmission through population based immunity. The causative agent (measles virus) is a negative strand ribonucleic acid (RNA) virus. Measles is considered a serious public health problem because its causative virus is transmitted through droplets or aerosols, can induce systemic infection, and suppress the immune response even following a long period of getting the infection. The standard vaccination of children against measles is through attaining a two-dose immunization schedule, as a single dose can only provide 15% immunity. It is necessary to reach and maintain 95% of the population immunization against measles. Despite the presence of an effective and safe attenuated live virus vaccine, measles is still considered a dangerous disease worldwide resulting in the death of 136,000 (mostly children) in the year 2022. Measles outbreaks are suspected and should be declared when the number of cases reported in a region exceeds the usual number of cases. The increment rate of reported measles cases and deaths from this illness in 2022 is 18% and 43% respectively, in comparison with the year 2021 across the globe.
Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation
(Multidisciplinary Digital Publishing Institute, 2014) Africa, Charlene W.J.; Nel, Janske; Stemmet, Megan C.
The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes.
Analyses of spermatozoa surface proteins using different separation techniques
(University of the Western Cape, 2013) Fortuin, Kay Arlene; Henkel, Ralph; Menkveld, Rudolf
Passage of spermatozoa through the female reproductive tract is essential for the regulation of fertilization, ensuring that healthy sperm reach the oocyte. Previous studies were devoted to morphological selection of sperm cells by the cervical mucus. However, research prove that the loss of integrity of the sperm plasma membrane is associated with infertile men, irrespective of their normal semen parameters. This indicates that the sperm plasma membrane plays an important role in fertilization. Further studies indicated that sperm surface proteins assist penetration through the female reproductive tract and would therefore provide useful insight in understanding other factors associated with male infertility. The aim of this project was to determine if there are any differences between sperm surface proteins of fertile donor samples in relation to infertile patient samples using different separation techniques and different detergents. Three different sperm separation techniques were employed, including wash, swim-up (SU) and Percoll density gradient centrifugation (DGC).Parallel to this, the deoxy-ribose nucleic acid (DNA) fragmentation of these cells were analysed for comparison of the extent of DNA damage induced due to different separation techniques used. This provided evidence that the best separation technique is the DGC as it minimises the amount of DNA fragmentation caused. Four different detergents were used in the process of extracting the membrane proteins from spermatozoa, namely sodium dodecyl sulphate (SDS), saponin,cetyl-trimethyl-ammonium bromide (CTAB), and TWEEN-20. The membrane proteins were then separated on a12% SDS poly-acrylamide gel electrophoresis (PAGE), and analysed by Coomassie blue and silver staining techniques as well as densitometry. Due to the different chemical nature of the detergents that extracted different surface proteins, CTAB (cationic) and SDS (anionic) extracted the most because of its strong solubilising abilities as non-ionic detergents. Common proteins that were extracted in donor samples included; 115, 92.5, 89, 61, 55.5, 51.5, 47, 44.5, 43, 38.5, 34 and 28 kDa proteins. In patients, commonly occurring proteins included; 92.5, 74.5, 70, 60.5, 51.5, 50, 44.5, 43, 36, 29.5, and 25.5 kDa proteins. Marked differences were found between membrane proteins extracted from donor samples in comparison to patient samples. Identification of these proteins was done using the SwissProt database and a literature search. Mostly non-genomic progesterone receptors were identified; others included oestrogen receptor, a phosphotyrosyl protein, P34H, equatorial segment protein, mannose lectin receptor, human guanylylcyclase receptor, epididymal protease inhibitor receptor, PH30 and estradiol binding protein. The function of the membrane surface proteins identified in this study plays a vital role in fertilization. A few of these functions include sperm attachment and binding to the oocyte as well as penetration thereof. Others play a role in signalling events such as capacitation, hyperactivation and acrosome reaction. The absence of these proteins in patient sperm possibly accounts for the functional inability to successfully achieve fertilization suggesting that this provides molecular insight to reasons for infertility amongst men. In addition to this, proteins presented by patient samples that were absent in healthy donors may too account for their infertility status. Estradiol binding protein and PH30 are two proteins presented only in patient samples. Their function plays a role in the inhibition of the acrosome reaction and sperm-egg fusion, respectively. In conclusion, these differences in protein expression between fertile donors and patients may form the molecular basis of infertility amongst men and indicates possibilities for novel proteonomic approaches to improve andrological diagnosis in future.
Analyzing free fatty acids in seminal plasma from asthenozoospermia patients undergoing antioxidant therapy
(SBRA - Associação Brasileira de Reprodução Assistida (Brazilian Society of Assisted Reproduction), 2025) Henkel, Ralf; Amirjannati, Naser; Asl, Mahdieh Aghabalazadeh
Objective: Different aspects of the functions of free fatty acid (FFA) in seminal plasma and their implications on male fertility are known. However, the profile of FFA in seminal plasma in asthenozoospermic patients following antioxidant therapy has not been studied. Methods: In this case-control study, the total antioxidant capacity (TAC) and FFA profile of the seminal plasma were determined in 80 patients (29 normozoospermic volunteers and 51 asthenozoospermic men) who were treated with antioxidants for three months. Results: The TAC level in normozoospermic men was significantly higher than in asthenozoospermic men before and after antioxidant therapy with even lower values after the treatment (p=0.0001). The most abundant identified FFAs in seminal plasma were palmitic acid, vaccenic acid, eicosatrienoic acid, stearic acid, and myristoleic acid. Palmitic acid was lower in asthenozoospermic patients (p=0.0001), and antioxidant treatment restored its level to near-control levels. Compared to normozoospermic controls, the level of eicosatrienoic acid is significantly lower in asthenozoospermia patients before (p=0.01) and after treatment (p=0.0001). Additionally, following oral antioxidant supplementation, the FFA pattern in asthenozoospermic patients changes to the pattern observed in normozoospermic men. However, these changes are not statistically significant. Conclusions: The TAC level in asthenozoospermic patients after antioxidant treatment did not change to the levels in the control group; it even dropped to a lower level following three months of treatment. Antioxidant treatment can change the level of the FFA compositions of seminal plasma
Antibacterial activity of some South African plant extracts against streptococcus mutans
(University of the Western Cape, 2015) Kelani, Madeha Mohammed; Hiss, Donavon; Mohammed, Ahmed
Good oral health has a major influence on the general quality of life and well-being. Several chronic and systemic diseases have been attributed to poor oral health. With the increasing incidence of oral diseases, the global need for alterative prevention and treatment methods and safe, effective, and economical products has expanded. There are many studies showed that Streptococcus mutans has been implicated as major etiological agent of dental caries. South African has very rich natural flora especially Cape region. Several South African medicinal plants have been used since immemorial time for treatment of different human pathologies including dental problems. The antibacterial activities of plants extracts have been recognized and documented scientifically during the last few decades. In this project we aimed at the screening of 31 South African plants randomly collected from Cape region for their antibacterial activity against Streptococcus mutans initially at two concentrations (500 and 100 µg/ml).MIC’s and MBC’s were determined for the active plant extracts, as well as the qualitative studies of the effect of the active extracts on the biofilm formation. The best or the most active safe plant (Psoralea fruticans) was submitted to chromatographic separation to isolate the bioactive compounds which could be responsible for such activity. Identification of the pure active compounds was carried out using different spectroscopic techniques. Finally the biological evaluation of the isolated pure compounds was measured against S. mutans and also the cytotoxicity studies in-vitro against normal cells lines was carried out.
Antibody production with synthetic peptides against human Coronavirus-NL63 ORF3 protein
(University of the Western Cape, 2025) Mnyamana, Yanga Eddie
Human Coronavirus (HCoV) NL63 was detected in an infant in the Netherlands in 2004 and will hereafter be referred to as CoV-NL63. Four years later, it was classified into Group 1 coronaviruses by the International Committee for Taxonomy of Viruses (ICTV), which was modified into alphacoronavirus in 2009. It appears that CoV‐NL63 originates from bats and its hosts are bats and palm civets. A 27,553‐bp CoV‐NL63 genome structure and the spike glycoprotein (S1 domain) use angiotensin‐converting enzyme 2 (ACE2) for infectious entry. Furthermore, CoV‐NL63 simplifies binding to ACE2 by attaching to heparan sulphate proteoglycans on the cell surface. ACE2 has a significant expression in airway differentiated epithelial cells and CoV‐NL63 enter these cells from their apical surface. It is imperative to note that CoV‐NL63, CoV‐229E, CoVHKU1 and CoV‐OC43 infect polarized epithelial cells, and the entry and release of these viruses are related to apical cells in addition to respiratory signs, there are two non-respiratory symptoms including gastroenteritis and Kawasaki disease, both of which are associated with CoV‐NL63. Moreover, neurological manifestations of CoV-NL63 have been reported, especially in children. The main aim of this research study was to generate monoclonal antibodies (mAbs) against the human coronavirus NL63 Open Reading Frame 3 (ORF3) protein. Firstly, bioinformatic tools were used to assist in identifying antigenic determinants and antigenic epitopes were used to generate peptides of ORF3 protein. Thereafter, the ORF3 protein was characterized using various molecular techniques across the bacterial and mammalian expression systems. A CoV-NL63 full-length ORF3 protein (Protein Identity Number: ABE97138.1) was utilized for the synthesis of the peptide from the N-terminus and peptides conjugated with a MAP; KLH and MAP+KLH linkage on the carboxyl end. The mAbs were generated in vivo by immunizing BALB/c mice. Antigen-specific ELISA assessed the antibody specificity and sensitivity. The mAbs that exhibited the highest specificity and sensitivity for antigenic peptide (s) were used to characterize the ORF3 protein by Western blot and immunofluorescence analysis (IFA).
The antihypertentive effect of aqueous extract O Africana leaves
(University of the Western Cape, 2007) Wang, Xu; Dietrich, Daneel; Johnson, Quinton; Dept. of Medical BioSciences; Faculty of Science
The incidence of cardiovascular diseases, including hypertension, is on the increase worldwide. Medicinal plants played an important role in the treatment of hypertension for centuries. Very few scientific studies have, however, been done to validate the use of these phytotherapies. O africana is on of the many phytotherapies that has been use indigenously for years to treat hypertension. The objectives of this study were to determine the most effective does of O africana aqueous extract which will reduce blood pressure; to determine whether chronic administration of O africana can be used to prevent and treat hypertension; to determine whether O africana exert its effects by modulation of the renin-angiotensin system.
Antimicrobial resistant Gram-positive cocci in pregnant mothers with aerobic vaginitis
(Infection Control Africa Network (ICAN), 2016) Kaambo, Eveline; Abrantes, Pedro Miguel dos Santos; McArthur, Carole P.; Africa, Charlene W.J.
The vaginal microbiota of a healthy asymptomatic woman consists of an extensive diversity of anaerobic and aerobic bacterial genera and species dominated by the microaerophilic genus Lactobacillus , known to inhibit the growth of potentially pathogenic non-acid tolerant microorganisms. An imbalance of species within this biofilm may result in endogenous opportunistic infections such as aerobic vaginitis (AV) caused by S. agalactiae and E. faecalis, which have been implicated in neonatal and obstetric sepsis. The prevalence and antimicrobial susceptibility of E. faecalis and S. agalactiae in pregnant women with AV in the Western Cape, South Africa was determined using standard microbiological culture methods and the Sensititre TREK system. AV was detected in 26.13% of the 199 tested pregnant women, with S. agalactiae and E. faecalis isolated from 32 and 20 mothers respectively. S. agalactiae and E. faecalis showed resistance to 12 of the 17 antibiotics tested, including those recommended for prophylaxis according to the CDC guidelines. The resistance of S. agalactiae and E. faecalis to commonly administered antimicrobials highlights the need for alternative treatment regimens for AV during pregnancy to reduce the risk of AV-associated negative pregnancy outcomes.
Antimicrobial-resistant Klebsiella species isolated from free-range chicken samples in an informal settlement
(Termedia Publishing House, 2012) Fielding, Burtram C.; Mnabisa, Amanda; Gouws, Pieter A.; Morris, Thureyah
Sub-therapeutic doses of antimicrobial agents are administered routinely to poultry to aid growth and to prevent disease, with prolonged exposure often resulting in bacterial resistance. Crossover of antibiotic resistant bacteria from poultry to humans poses a risk to human health. In this study, 17 chicken samples collected from a vendor operating in an informal settlement in the Cape Town Metropolitan area, South Africa were screened for antimicrobial-resistant Gram-negative bacilli using the Kirby Bauer disk diffusion assay. In total, six antibiotics were screened: ampicillin, ciprofloxacin, gentamicin, nalidixic acid, tetracycline and trimethoprim. Surprisingly, Klebsiella ozaenae was identified in 96 and K. rhinoscleromatis in 6 (n = 102) of the samples tested. Interestingly, ~40% of the isolated Klebsiella spp. showed multiple resistance to at least three of the six antibiotics tested. Klebsiella ozaenae and K. rhinoscleromatis cause clinical chronic rhinitis and are almost exclusively associated with people living in areas of poor hygiene.

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