Co-occurrence of Sympatric Poroderma Species
- Authors: Watson, Ralph Gareth Andrew
- Date: 2024-04-05
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/436649 , vital:73289 , DOI 10.21504/10962/436649
- Description: Species exploiting similar ecological niches are expected to adapt their behaviour, which can either promote or hinder coexistence. This study examined the ecological (dis)similarity between the endemic Poroderma africanum (pyjama catshark) and Poroderma pantherinum (leopard catshark) in Mossel Bay, South Africa. The co-occurrence of these species was examined along the ecological axes of time, trophic position and space, between October 2015 and April 2018, through the use of Baited Remote Underwater Videos (BRUV), gastric lavage, and acoustic telemetry. Through the deployment of 197 BRUVs, P. africanum showed a seasonal, higher Relative Abundance (RA = 0.52), occurring more frequently during winter months, while showing an overall decline in RA over the course of the study period. Poroderma pantherinum on the other hand, showed a lower, unseasonal RA (0.20), remaining relatively stable throughout the study period. The BRUV deployments indicated that the two species showed a positive co-occurrence with one other, being sighted in BRUV deployments more frequently together as opposed to in isolation/at random. Acoustic telemetry indicated that the two species were active during different diel periods, influenced by a complex combination of tidal and diel rhythms, while P. pantherinum showed a higher residency compared to P. africanum (P. pantherinum: Continuous Residency Time (CRT)24 = 3.32 days (mean), 95% CI: 2.53–4.11 days; P. africanum: CRT24 = 2.01 days, 95% CI: 1.66–2.36 days). While the two species are sympatric in nature, and have an overlapping, endemic, distribution, acoustic telemetry indicated that 1 ABSTRACT P. africanum showed higher degrees of movement throughout the acoustic receiver array (P. africanum: edge density (ED) = 0.25; P. pantherinum: ED = 0.12); however, certain areas of the bay showed to be of high importance for both species. Both species revealed high levels of intra- and inter-specific variation in both residency and movement behaviour. Gastric lavage indicated partially overlapping trophic niches, between the two Poroderma spp. Poroderma africanum had a generalist diet, dominated by teleosts (Index of Relative Importance (IRI)% = 22.69), octopus (IRI% = 11.48) and discarded bait (IRI% = 64.54), while P. pantherinum showed indications of being a specialist predator, with a diet dominated by cephalopods (IRI% = 83.68). The two Poroderma spp. showed a partially overlapping, but separate trophic niches, while displaying spatial dissimilarity in diet. The study suggests that the two species are able to coexist within the same geographical area through niche differentiation across trophic and temporal ecological axes, with varying spatial use. The intra- and inter-specific differences between the two species may complicate elasmobranch management efforts for these co-occurring endemic catsharks, and as such, efforts should follow either an individual species approach, which is often not feasible, or an ecosystem-based approach, as opposed to considering the genus as a whole. , Thesis (PhD) -- Faculty of Science, Ichthyology and Fisheries Science, 2024
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- Date Issued: 2024-04-05
In silico characterization of missense mutations in infectious diseases: case studies of tuberculosis and COVID-19
- Authors: Barozi, Victor
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431626 , vital:72791 , DOI 10.21504/10962/431626
- Description: One of the greatest challenges facing modern medicine and the global public health today is antimicrobial drug resistance (AMR). This “silent pandemic,” as coined by the world health organization (WHO), is steadily increasing with an estimated 4.95 million mortalities attributed to AMR in 2019, 1.27 million of which were directly linked to AMR. Some of the contributors to AMR include self-prescription, drug overuse, sub-optimal drug prescriptions by health workers, and inaccessibility to drugs, especially in remote areas, which leads to poor adherence. The situation is aggravated by the upsurge of new zoonotic infections like the coronavirus disease 2019, which present unique challenges and take the bulk of resources hence stunting the fight against AMR. Quite alarming still is our current antimicrobial arsenal, which hasn’t had any novel antimicrobial drug discovery/addition, of a new class, since the 1980s. This puts a burden on the existing broad-spectrum antimicrobial drugs which are already struggling against multi-drug resistant strains like multi-drug resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB). Besides the search for new antimicrobial agents, the other avenue for addressing AMR is studying drug resistance mechanisms, especially single nucleotide polymorphisms (SNPs), that change drug target characteristics. With the advancement of computational power and data storage resources, computational approaches can be applied in mutational studies to provide insight into the drug resistance mechanisms with an aim to inform future drug design and development. Therefore, in the first part of this thesis, we employ integrative in silico approaches, including 3D structure modeling, molecular dynamic (MD) simulations, comparative essential dynamics (ED), and protein network analysis approaches i.e., dynamic residue network (DRN) analysis to decipher drug resistance mechanisms in tuberculosis (TB). This involved an investigation of the drug resistance mutations in the catalase-peroxidase (KatG) and pyrazinamidase (MtPncA) enzymes which are responsible for activation of TB first-line drugs; Isoniazid (INH) and Pyrazinamide (PZA), respectively. In the case of KatG, eleven high confidence (HC) KatG mutations associated with a high prevalence of phenotypic INH resistance were identified and their 3D structures modeled before subjecting them to MD simulations. Global analysis showed an unstable KatG structure and active site environment in the mutants compared to the wildtype. Active site dynamics in the mutants compromised cofactor (heme) interactions resulting in less bonds/interactions compared to the wildtype. Given the importance of the heme, reduced interactions affect enzyme function. Trajectory analysis also showed asymmetric protomer behavior both in the wildtype and mutant systems. DRN analysis identified the KatG dimerization domain and C-terminal domain as functionally important and influential in the enzyme function as per betweenness centrality and eigenvector centrality distribution. In the case of the MtPncA enzyme, our main focus was on understanding the MtPncA binding ability of Nicotinamide (an analogue of PZA) in comparison to PZA, especially in the presence of 82 resistance conferring MtPncA mutations. Like in KatG, the mutant structures were modeled and subjected to MD simulations and analysis. Interestingly, more MtPncA mutants favored NAM interactions compared to PZA i.e., 34 MtPncA mutants steadily coordinated NAM compared to 21 in the case of PZA. Trajectory and ligand interaction analysis showed how increased active site lid loop dynamics affect the NAM binding, especially in the systems with the active site mutations i.e., H51Y, W68R, C72R, L82R, K96N, L159N, and L159R. This led to fewer protein-ligand interactions and eventually ligand ejection. Network analysis further identified the protein core, metal binding site (MBS), and substrate binding site as the most important regions of the enzyme. Furthermore, the degree of centrality analysis showed how specific MtPncA mutations i.e., C14H, F17D, and T412P, interrupt intra-protein communication from the MtPncA core to the MBS, affecting enzyme activity. The analysis of KatG and MtPncA enzyme mutations not only identified the effects of mutations on enzyme behaviour and communication, but also established a framework of computational approaches that can be used for mutational studies in any protein. Besides AMR, the continued encroachment of wildlife habitats due to population growth has exposed humans to wildlife pathogens leading to zoonotic diseases, a recent example being coronavirus disease 2019 (COVID-19). In the second part of the thesis, the established computational approaches in Part 1, were employed to investigate the changes in inter-protein interactions and communication patterns between the severe acute respiratory coronavirus 2 (SARS-CoV-2) with the human host receptor protein (ACE2: angiotensin-converting enzyme 2) consequent to mutations in the SARS-CoV-2 receptor binding domain (RBD). Here, the focus was on RBD mutations of the Omicron sub-lineages. We identified four Omicron-sub lineages with RBD mutations i.e., BA.1, BA.2, BA.3 and BA.4. Each sub-lineage mutations were modeled into RBD structure in complex with the hACE2. MD analysis of the RBD-hACE2 complex highlighted how the RBD mutations change the conformational flexibility of both the RBD and hACE2 compared to the wildtype (WT). Furthermore, DRN analysis identified novel allosteric paths composed of residues with high betweenness and eigenvector centralities linking the RBD to the hACE2 in both the wildtype and mutant systems. Interestingly, these paths were modified with the progression of Omicron sub-lineages, highlighting how the virus evolution affects protein interaction. Lastly, the effect of mutations on S RBD and hACE2 interaction was investigated from the hACE2 perspective by focusing on mutations in the hACE2 protein. Here, naturally occurring hACE2 polymorphisms in African populations i.e., S19P, K26R, M82I, K341R, N546D, and D597Q, were identified and their effects on RBD-hACE2 interactions investigated in presence of the Omicron BA.4/5 RBD mutations. The hACE2 polymorphisms subtly affected the complex dynamics; however, RBD-hACE2 interaction analysis showed that hACE2 mutations effect the complex formation and interaction. Here, the K26R mutation favored RBD-hACE2 interactions, whereas S19P resulted in fewer inter-protein interactions than the reference system. The M82I mutation resulted in a higher RBD-hACE2 binding energy compared to the wildtype meaning that the mutation might not favor RBD binding to the hACE2. On the other hand, K341R had the most RBD-hACE2 interactions suggesting that it probably favors RBD binding to the hACE2. N546D and D597Q had diminutive differences to the reference system. Interestingly, the network of high betweenness centrality residues linking the two proteins, as seen in the previous paragraph, were maintained/modified in presence of hACE2 mutations. HACE2 mutations also changed the enzyme network patterns resulting in a concentration of high eigenvector centrality residues around the zinc-binding and active site region, ultimately influencing the enzyme functionality. Altogether, the thesis highlights fundamental structural and network changes consequent to mutations both in TB and COVID-19 proteins of interest using in silico approaches. These approaches not only provide a new context on impact of mutations in TB and COVID target proteins, but also presents a framework that be implemented in other protein mutation studies. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2023
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- Date Issued: 2023-10-13
Prediction of mass spectra using an ab initio approach
- Authors: Novokoza, Yolanda
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/${Handle} , vital:72818
- Description: Access restricted. Expected release date in 2025. , Thesis (PhD) -- Faculty of Science, Chemistry, 2023
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- Date Issued: 2023-10-13
The heterologous expression and in vitro biochemical characterization of the Hsp70 escort protein 1 and mitochondrial Hsp70 partner proteins of the Trypanosoma brucei parasite and humans
- Authors: Mahlalela, Maduma Ernst
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431832 , vital:72807 , DOI 10.21504/10962/431832
- Description: The 70 kDa family of heat shock proteins (Hsp70) plays a central role in the maintenance of cellular proteostasis, with paralogues occurring in all the major compartments of the eukaryotic cell. Hsp70s act in conjunction with proteins known as co-chaperones, as part of the larger molecular chaperone network. In the mitochondrion, Hsp70 (mtHsp70) is responsible for the import of proteins synthesized in the cytosol, protein folding in the matrix and the maintenance of the iron-sulphur cluster. In human cells mtHsp70 (HSPA9) is also referred to as mortalin, as the knockdown of the protein leads to cell mortality. Trypanosoma brucei is the causative agent of sleeping sickness in humans and nagana in animals. In the T. brucei parasite there are three identical mtHsp70 (TbmtHsp70) proteins that are produced, forming part of the Hsp70 machinery that is essential for parasite survival. In humans, the levels of HSPA9 are often elevated in non-communicable diseases such as cancer and neurodegeneration. Despite their vital cellular roles, mtHsp70s are characteristically prone to self-aggregation. The binding of the Hsp70 escort protein (Hep1) is required to prevent the aggregation of mtHsp70 proteins, enabling the proteins to function. In many non-communicable diseases, mtHsp70 and other molecular chaperones such as heat shock protein 90 (Hsp90) are being investigated as potential drug targets. Existing anti-trypanosomal drugs for treating sleeping sickness are toxic, having adverse side effects that are potentially lethal. Investigations into Hsp70s, and other molecular chaperones, form part of the research into the discovery of novel and efficacious therapeutics. This is the first study to characterise Hep1 and investigate its partnership with mtHsp70 in T. brucei. The overall aim of this study was to comparatively assess the T. brucei and human mtHsp70/Hep1 partnerships. The putative T. brucei Hep1 (TbHep1) orthologue was analysed in silico, and it was found to possess a zinc finger domain consisting of anti-parallel β-sheets that are characteristic of canonical Hep1 proteins, whilst the N-terminal domain was unstructured. Based on sequence analysis, the regions outside of the zinc finger domains lacked conservation. Despite the lack of sequence conservation, the N- and C-terminal regions of TbHep1 shared segments of similarity with Hep1 orthologues of other kinetoplastid and trypanosomal orthologues. The same held true for the N- and C-termini of human Hep1 (HsHep1) when compared to other Hep1 orthologues of mammalian origin. Biochemical analysis revealed TbmtHsp70 and HSPA9 to be prone to self-aggregation, which was reduced by co-expression with TbHep1 and HsHep1, respectively. Recently Hep1 proteins have been determined to be present in the cytosol. In this study, TbHep1 and HsHep1 also interacted with the cytosolic Hsp70s, HSPA1A and TbHsp70, by preventing their thermally induced aggregation and stimulating their ATPase activities. TbHep1 and HsHep1 also suppressed the thermally induced aggregation of the model substrates malate dehydrogenase and citrate synthase, independently of Hsp70. To date, only two Hep1 orthologues, HsHep1 and LbHep1, have been found to function in a similar manner to a J-protein co-chaperone by stimulating the ATPase activities of their partner mtHsp70 proteins. In this study, TbHep1 stimulated the ATPase activity of TbmtHsp70. HsHep1 also stimulated the ATPase activity of TbmtHsp70. However, the mechanism of action still needs to be determined. This study also explored the potential of the Hep1 orthologues to be functionally activated by oxidative stress, which is prevalent in mitochondria. The abilities of TbHep1 and HsHep1 to reduce the thermally induced aggregation of malate dehydrogenase were enhanced under oxidative conditions. Disrupting the function of Hep1 has been found to eventually lead to cell death, and given the critical role played by mtHsp70 in the cell, this partnership could be exploited as a potential drug target. In conclusion, this study demonstrated that TbHep1 and HsHep1 functionally interact with mtHsp70s, whilst also possessing independent chaperone activities that are also potentially influenced by the environmental redox state. , Thesis (PhD) -- Faculty of Science, Biotechnology Innovation Centre, 2023
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- Date Issued: 2023-10-13
Wildlife-vehicle collisions mitigation measures using road ecological data and deep learning
- Authors: Nandutu, Irene
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/431907 , vital:72814
- Description: Access restricted. Expected release in 2025. , Thesis (PhD) -- Faculty of Science, Mathematics, 2023
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- Date Issued: 2023-10-13
“How do you feel about the abortion?”: pre-termination of pregnancy counselling in the public health sector in the Eastern Cape
- Authors: Du Toit, Ryan Rudolph
- Date: 2023-10-13
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/437238 , vital:73355 , DOI 10.21504/10962/437239
- Description: Pre-abortion counselling, as an aspect of abortion provision, has received growing research interest in various contexts. Much of the research has primarily focused on whether abortion counselling takes place, the experiences of women and/or counsellors (usually through retrospective interviews and surveys), and the content discussed during the counselling session (often policy regulated). Such research has proven vital to addressing the various reproductive issues facing women seeking an abortion worldwide. However, little research has focused on how pre-abortion counselling as an everyday institutional practice is conducted at a conversational level in the medical setting. By drawing on both conversation analysis and discursive psychology, this study explored how pre-abortion counselling was conducted in the public health sector in South Africa. The study involved recording the conversation during pre-abortion counselling and analysing it in terms of its content, in particular, the discourses drawn on by all parties involved, and its structure and delivery. The data were collected from three public hospitals in the Eastern Cape of South Africa and involved the audio recording of pre-abortion counselling sessions as part of abortion services. In total, 28 counselling sessions were recorded: 21 were individual sessions, and 7 were group counselling sessions. At two of the sites, counselling was conducted by registered midwives who worked at the hospital. At one site, an external Christian organisation volunteered trained counsellors to counsel women at the hospital free of charge. Using conversation analysis, counselling sessions were analysed in terms of the main projects. Seven key projects were identified: (1) Context setting, (2) History taking, (3) Establishing reason for abortion, (4) Presenting options, (5) Providing procedural information, (6) Obtaining verbal informed consent, and (7) Discussion of family planning. Each project is explored in terms of what discourses and subject positions featured when speakers were orienting to a specific project. This process highlighted how the conversational projects and their respective goals enable the deployment of certain problematic discourses and interactive/reflexive positionings. Discourse analysis revealed a clustering of discourses around two central themes. In the first clustering, the discourses were primarily used to discuss the (1) medically related issues underpinning the abortion procedure [medical discourse, responsibilization discourse, risk discourse, and discourse of support]. Talk using these discourses positioned women as patients needing medical intervention, responsibilised women for conceiving, playing an active role in their termination, and navigating all the psychological and physical risks “associated” with abortion. The discourse of support illustrates how support was spoken about in the interaction whereby patients were constructed as subjects who required support and nurses/counsellors as the ones who offered the support. In the second clustering, the discourses (2) focused on women and the foetus. These discourses [reproductive choice, religious, pronatalist, and foetal personhood discourses] positioned women as being responsible for making a choice regarding their pregnancy and the consequences that may result. In addition, a religious discourse coupled with a pronatalist discourse was used to construct the pregnancy and motherhood as desirable and part of “God’s plan”, whereas the foetus was spoken about as a “gift from God”. The foetal personhood discourse was used to construct the foetus as a living and functional human. This research provides evidence of how abortion counselling is problematic at various levels. At a practical level, there is a lack of standardisation in the delivery of abortion counselling (e.g., variation in key projects, where the counselling is mandated, time taken, nurse/counsellor training, content and format – group vs. individual counselling). At a discursive level, the use of certain discourses works to render the counselling directive through : (1) awfulizing abortion by providing misinformation about the abortion procedure, foetus and post-abortion psychological distress, (2) chastising and responsibilising women for conceiving, (3) constructing abortion as immoral, the ending of life and not in line with God’s plan, (4) constructing parenthood as the preferred choice, (5) delegitimising abortion as a resolution for pregnancy when compared to the other options (e.g., parenting or adoption), and finally (6) providing counselling that does not take into account the broader socio-political contexts. Recommendations for future research are put forward, and a call to move to a reparative justice framework is made by highlighting how it can be used to identify and understand reproductive injustices as they occur along four intersecting dimensions: (1) Individual material, (2) Collective material, (3) Individual symbolic, and (4) Collective symbolic. , Thesis (PhD) -- Faculty of Humanities, Psychology, 2023
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- Date Issued: 2023-10-13
Molecular characterization of integrons and their associated gene cassettes in multidrug-resistant enterobacteriaceae isolates from environmental sources and the exploration of antibiotic combination against some resistant strains
- Authors: Fadare, Folake Temitope https://orcid.org/0000-0001-5779-9798
- Date: 2023
- Subjects: Enterobacteriaceae , Molecular microbiology , Enterobacteria
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27809 , vital:69942
- Description: Globally, the increasing rate of antimicrobial resistance against our currently available drugs has been a serious public concern. Due to the selective nature of antibiotics, bacteria are expected to develop resistance against them over time, but the current scourge of antimicrobial resistance is aggravated by factors other than the expected evolutionary trend. The use and overuse of antibiotics in clinical and agricultural contexts have led to the fast rise of multidrug-resistant MDR microorganisms. A scenario that necessitates an upsurge in the clinical failures observed with our current drug arsenals is expected to rise if left unchecked. One of the significant drivers implicated in the spread of antimicrobial resistance genes is the integrons. These are mobile genetic elements found on pathogenicity islands, transposons, and plasmids, easing their distribution among various bacteria. They are considered efficient gene expression systems that naturally capture, integrate gene cassettes GCs and immediately express the captured antimicrobial resistance genes on the GCs due to the inherent promoters on their structures. Integrons have been known to confer resistance against most classes of antibiotics. These include all known β-lactams, chloramphenicol, trimethoprim, erythromycin, aminoglycosides, quinolones, streptothricin, lincomycin, rifampicin, fosfomycin, and antiseptics of the quaternary ammonium compound family. They have been detected in bacterial populations under direct or indirect antibiotic pressure in clinical, agricultural, and environmental contexts. The emergence of MDR in Enterobacteriaceae is a critical public health issue that has attracted the World Health Organization WHO, which classified them as one of the critical priority pathogens urgently requiring new antibiotics. The resistance phenomenon has proven most of the current antibiotics ineffective, further compounded by the slow pace of the discovery of new antibiotics, necessitating the hunt for new, practical remedies. One of such is the exploration of synergy among existing antibiotics. Two medications combined have a higher impact, thereby allowing current antibiotics to be salvaged for use in treating MDR bacteria, even if the bacteria are resistant against one or both antibiotics separately. Hence, this research focused on the occurrence and prevalence of multidrug resistance and the characterization of integrons and their associated gene cassettes in members of Enterobacteriaceae, including Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Citrobacter spp. recovered from animal droppings, rivers, and effluents of hospital and wastewater treatment plants in Eastern Cape Province, South Africa. The inhibitory effect of combining two drugs belonging to different antibiotic classes to obtain a possible potentiating effect against some multidrug-resistant Enterobacteriaceae isolates harbouring integrons were examined and studied. The isolates were identified using the conventional molecular Polymerase Chain Reaction with specific primers. The antimicrobial resistance profile and the production of Extended-spectrum and metallo β-lactamase were detected using disk diffusion technique DDT, double-disk synergy test DDST, and ethylenediaminetetraacetic acid EDTA tests, respectively. The PCR-based screening method, DNA sequencing analyses, and restriction fragment length polymorphism RFLP were used to characterize the integrons and their associated GCs. Furthermore, Enterobacterial Repetitive Intergenic Consensus ERIC PCR determined the genotypic relationships between some specific species. The various antibiotics' minimum inhibitory concentration MIC was determined using the broth microdilution, while the checkerboard method was used to determine the fractional inhibitory concentration indices FICIs. The time-kill assays TKAs were further used to confirm the synergism observed from the checkerboard assays. Most of the isolates were resistant against most antibiotics tested and were considered MDR. The least resistance was observed against imipenem, a carbapenem, one of the drugs of last resort. Also present were the ESBL and MBL producers, with a few isolates co-producing the enzymes. A high prevalence of integrons was observed in the isolates, with class 1 integrons being the most frequently detected. Some isolates co-harboured the intI1 and intI2 genes and were classified as class1 plus 2 integrons. Although Citrobacter spp. had the least number of isolates among the Enterobacteriaceae studied, it harboured the most diverse gene cassette arrays. The various gene cassette arrays were identified as follows: For Klebsiella spp. Aac 6 Ib, aadA1 dfrA1, and dfrA1 sat2; for Citrobacter spp., dfrA5 aac3 Ib, aac6 ib, aadA1dfrA1 aadA1, aadA1-dfrA1, aadA5 dfrA17, and dfrA21-aac3-Ib; for E. coli dfrA21- aac-3-Ib, dfrA5-aac-3-Ib, aadA1 dfrA1, and aadA5 dfrA17 and for E. cloacae aadA1 dfrA1, dfrA7 dfrA21 dfrA5 aac 3 Ib, and dfrA1 sat2. The GC array dfrA1 sat2 was the only array detected in class 2 integrons which are analogous to that found in Tn7, dfrA1-sat2-aadA1, with the deletion of the last GC aadA1. These detected GCs confer resistance against aminoglycosides, including streptomycin and spectinomycin, and trimethoprim, further increasing the resistance spectrum of the bacterial species harbouring them. The detection of integrons and their associated GC and the presence of these β-lactamases is also associated with coresistance against other classes of antibiotics by bacterial species harbouring them, further limiting treatment options. The checkerboard assays combining antibiotics against these drug-resistant integron harbouring Enterobacteriaceae revealed that 26.3 percent 10 over 38 of the interactions were categorized as synergistic, while 73.7 percent 28 over 38 were indifferent. None of the combinations was antagonistic. The TKAs revealed all the synergistic interactions as bactericidal. Therefore, the combinations of gentamicin with tetracycline, ciprofloxacin, and ceftazidime against Multidrug-resistant MDR Klebsiella pneumoniae; tetracycline-ceftazidime combination against MDR Escherichia coli, colistin combinations with ceftazidime and gentamicin, and tetracycline-gentamicin combinations against MDR Citrobacter freundii may be future therapeutic alternatives. , Thesis (MSci) -- Faculty of Science and Agriculture, 2023
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- Date Issued: 2023
The dynamics in implementing Inclusive Education in South Africa: Case studies of four Primary Schools in KwaZulu-Natal
- Authors: Nzuza, Zakhele Dennis
- Date: 2023
- Subjects: Inclusive education
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/26219 , vital:64974
- Description: The study explored the implemention of inclusive education in primary schools in the uMgungundlovu area, in the province of KwaZulu-Natal, South Africa. Locally and globally, the notion of inclusive education has presented various difficulties relating to the understanding stakeholders have of inclusive education and also in terms of embracing it and implementing it in schools. Stakeholders in South Africa have experienced similar challenges regarding a clear and common understanding of inclusive education and ensuring effective implementation. Despite various reforms adopted by the South African government, learners experiencing barriers to learning have persistently suffered inadequate access to quality education and equal learning opportunities. The reviewed literature has highlighted numerous challenges that have constrained effective implementation of inclusive education in South African schools. The reviewed literature also indicated that some teachers had negative attitudes towards inclusive education, and that such attitudes were linked to the lack of clear understanding of what inclusive education was about. At the core of this study is the fact that very little is known in South Africa about the implementation of inclusive education. Therefore, this study sought to unravel how chools implement inclusive education and, in that process, contribute to a deeper understanding of this phenomenon. The study utilised the Theory of Planned Behaviour as a theoretical framework and inclusive pedagogy as a conceptual framework to explore the implementation of inclusive education in four study schools. A qualitative approach underpinned by an interpretive research paradigm was adopted. Purposive sampling techniques were used to select twenty educators, four learners experiencing barriers to learning and four parents of learners experiencing barriers to learning to participate in this study. Four techniques were used to produce qualitative data, namely, semi-structured interviews, observations, documents’ review, and focus group discussions. Semi-structured interviews with educators and learners experiencing barriers to learning were utilised to generate data in the four selected primary schools. In addition to semi structured interviews, learners were also observed during lessons. Relevant documents kept in the schools were also reviewed to augment data generated through interviews. Focus group discussions were held with four parents of the learners experiencing barriers to learning. Data were analysed employing qualitative content analysis to come up with themes. The findings revealed that there was no common understanding amongst the teachers about what constituted inclusive education. Most educators understood inclusive education as referring to accommodating all learners in the classroom to reach their potential. These educators would help all learners, including those with barriers to learning thus contributing to the implementation of inclusive education in their schools. However, the findings also revealed that some educators understood inclusive education as referring to a situation where all learners received quality education, but those with barriers to learning being accommodated in special schools or special classrooms separate from their counterparts. The findings indicated that there was a lack of knowledge about inclusive education and such a lack contributed to misunderstandings about the essence of inclusive education. In addition, teachers lacked skills in dealing with learners experiencing barriers to learning, resulting in inefficient and ineffective implementation of inclusive education. It was evident from the findings that the curriculum was inflexible and the teachers lacked capacity to customise the content to the needs of all the learners, especially those experiencing learning barriers. Therefore, for teachers to implement inclusive education, it was necessary that content had to be flexible to meet the educational needs of all learners. The findings further revealed that using various teaching methods, such as visual objects and demonstrations was helpful in adapting the rigid curriculum and making it user friendly for learners experiencing barriers to learning. In addition, the research findings revealed that group work and peer learning assisted educators to implement inclusive education. Research findings also revealed that implementing inclusive education was hindered by various systematic factors, such as lack of parental support, overcrowding in classrooms, and socioeconomic challenges. I concluded that there is a remarkable knowledge deficit that can be addressed by training, including pre-service and ongoing professional development activities for teachers. I can also conclude that based on the findings educators require training on inclusive education, beginning with teachers currently in the system. The training can then be included in the curriculum of pre-service educators so that they can obtain a clear understanding of inclusive education and thus develop positive attitudes towards inclusive education. Similarly, school management teams require training on their own so that they can be able to provide adequate and effective support to the teachers in the classrooms. Another recommendation is that educators should be capacitated and developed in inclusive education to enhance their confidence in delivering the curriculum and to handle learners experiencing barriers to learning. Similarly, it is recommended that there be a collaboration between schools, homes, and other stakeholders to assist learners experiencing barriers to learning on their education journey, thus effectively implementing inclusive education in schools. Finally, a model for the improvement of inclusive education is proposed. , Thesis (PhD) -- Faculty of Education, 2023
- Full Text:
- Date Issued: 2023
The Training of pre-service science teachers in the integration of Information and Communication Technology integration in Science teaching: A case of two colleges of education in The Volta Region of Ghana
- Authors: Ofori, Mac-Jones
- Date: 2023
- Subjects: Teachers -- Training of , Science -- Study and teaching , Information technology -- Study and teaching
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/27898 , vital:70467
- Description: The study was carried out to investigate the training of pre-service Science teachers in the integration of Information and Communication Technology (ICT) in Science teaching at two colleges of education in the Volta region of Ghana. The study aimed to recommend a framework that can be used to enhance the training in ICT integration competencies of pre-service Science teachers at colleges of education in the country. The study was underpinned by two theoretical frameworks: Rogan and Grayson’s curriculum implementation framework and Guzman and Nussbaum’s ICT integration framework and was located within the interpretive paradigm. The qualitative research approach was adopted to generate data on the types of ICT integration competences that pre-service Science teachers are trained in, the pedagogical strategies used, the support provided, and the challenges faced during the training. The study adopted the explanatory case study design. Convenience and purposive sampling were used to select the study sites and participants respectively, which consisted of two teacher education colleges, two heads of Science department, ten lecturers, and 20 pre-service Science teachers. The study’s data collection methods were semi-structured face-to-face interviews with the lecturers, focus group discussions with the pre-service Science teachers, non-participatory lesson observation, and document analysis. The data was analysed using thematic approach. The study established that pre-service Science teachers at the two colleges received training in mastering the usage of ICT tools, relating ICT to teaching; using ICT for assessment and providing feedback, creating an appropriate environment for ICT integration, and developing positive attitudes toward ICT usage. The study revealed the pedagogical strategies used for training the pre-service Science teachers in ICT integration competencies to include a standalone ICT course, demonstration, group work, self-learning and how assessment is carried out. The study also established that there was support from both within and without the college environment in training pre-service Science teachers, although this was inadequate. The major challenges found by the study to be hindering effective pre-service teacher training in ICT integration competencies were lack of technical know-how among lecturers, poor pre-service Science teachers’ backgrounds in ICT, inadequate ICT resources and infrastructure, prolonged organisational and management bureaucracy, and insufficient funding of ICT. The recommendations made included the need for upgrading infrastructure in the colleges while also upgrading lecturers’ competencies in handling ICT in the colleges. An alternative training framework for preparing pre-service Science teachers in ICT integration competencies was also proposed. , Thesis (MEd) -- Faculty of Education, 2023
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- Date Issued: 2023