Division of Molecular Biology & Human Genetics
Mycobacteriology: Host-Pathogen Mycobactomics
Prof. Samantha Sampson
Prof Sampson is a tuberculosis (TB) researcher with expertise in mycobacterial genetics, microbiology, immunology and animal models of TB. Prof. Sampson obtained her PhD from Stellenbosch University, and undertook post-doctoral training at the Harvard University School of Public Health and Imperial College London (where she held a Wellcome Trust Research Career Development Fellowship). Upon being awarded a SARChI Chair in Mycobactomics, she returned to South Africa to establish a research group focused on TB host-pathogen interactions within the DST/NRF Centre of Excellence in Biomedical Tuberculosis Research in the Division of Molecular Biology and Human Genetics.
Dr. Nastassja Kriel
The isolation and characterization of Mycobacterium tuberculosis persister cells
Dr. Kriel's research centers around understanding the genes and pathways associated with Mycobacterium tuberculosis persister formation. Persister infections prevent the sterilization of infections and have the potential to reactivate following treatment and cause disease. Using a variety of omics technologies, Dr Kriel's research aims to provide a global overview of persister regulatory pathways required for persister formation.
Dr. Zimvo Obasa
Nanoparticle-based host-directed therapies for eradication of Mycobacterium tuberculosis in mice
Zimvo's post-doctoral research project focuses on assessing in vivo responses to and efficacy of novel nanoparticle (NP) formulations as a host-directed therapy for the eradication of Mycobacterium tuberculosis in C3HeB/FeJ (Kramink) mice. Utilizing the Kramnik mouse strain provides a valuable opportunity to assess the influence of NPs on immuno-pathology (and vice versa). Knowledge gained from this project could ultimately contribute to improved TB control strategies, specifically more effective drug treatment regimens.
|Supervisor||Prof. Sam Sampson|
|Co-Supervisors||Dr. Jomien Mouton / Dr. Liezel Smith|
|Life outside the lab||Baking / Taking long walks on the beach / Cleaning|
Su-Mari du Plessis
Biomimetic nanoparticle-based host-directed therapy (HDT) for the eradication of Mycobacterium tuberculosis
Su-Mari's PhD aims at investigating the immune-stimulating effects of polymer-based and metal-organic framework (MOF) nanoparticles (NPs) functionalized with curdlan and mycolic acids. Curdlan is a naturally occurring polysaccharide known to stimulate an antibacterial response and mycolic acids are the dominant class of lipids found on the surface of Mycobacterium tuberculosis. Curdlan and mycolic acids are added to the surface of MOF NPs, where they are able to alter the shape of MOF NPs, allowing the NPs to closely mimic Mycobacterium tuberculosis. This will allow Su-Mari to investigate the biomimetic ability of NPs by investigating the stimulated antibacterial immune response. By upregulating the immune response, Su-Mari intends to create a host-directed therapeutic anti-TB approach that focuses on the processes that contribute to mycobacterial killing, instead of killing the bacteria itself.
Functional characterization of T-cell immunogenicity of PPE_MPTR proteins of Mycobacterium tuberculosis
Esther obtained her Master of Science in Immunology and Clinical Microbiology at Makerere University, Uganda. Esther joined the Division of Molecular Biology and Human Genetics in 2021 as a PhD student where she intends to characterize the T-cell immune response to PPE_MPTR proteins of Mycobacterium tuberculosis.
|Supervisor||Prof. Samantha Sampson|
|Co-supervisor ||Prof. Andre Loxton / Dr. Nastassja Kriel|
|Life outside the lab||Spending time with friends / swimming / hiking / travelling|
Investigating heterogeneity in Mycobacterium tuberculosis as related to clinical outcomes
Julian obtained his BSc and BSc (Hons) in Biotechnology from the University of Western Cape and his MSc from Stellenbosch University in 2017, 2018 and 2021 respectively. His research currently aims to develop and validate models reporting on clinically relevant Mycobacterium tuberculosis phenotypic heterogeneity. There is anecdotal evidence of bacterial heterogeneity, but the importance hereof for TB treatment response, immune responses, and disease outcomes remains unknown. Julian will investigate this by utilizing bone marrow-derived macrophage stress models, flow cytometry and omics to measure the heterogeneity of Mycobacterium tuberculosis populations. This work provides insight into heterogeneity with Mycobacterium tuberculosis populations, with the ultimate goal of helping identify markers related to treatment response and improved treatment approaches.
|Supervisor||Prof. Samantha Sampson|
|Co-supervisor||Prof. Bavesh Kana / Dr. Nastassja Kriel|
|Life outside the lab||Hiking / Baking / Cooking / Outdoor chilling / Dogs|
Tayla Juliet Smith
Efficacy of biomimetic nanoparticles against Mycobacterium tuberculosis ΔleuDΔpanCD persister populations
Tayla joined the Host-Pathogen Mycobactomics Research group as an honours student in 2021. In 2022, Tayla started her MSc degree where she intends to use a macrophage infection model to assess whether treatment with biomimetic nanoparticles will lead to the elimination of persister cells within the macrophage. She is also exploiting the nature of the double auxotroph Mycobacterium tuberculosis ΔleuDΔpanCD using a nutrient deprivation model to assess its ability as an in vitro persister model.
Supervisor Prof. Samantha Sampson
Co-supervisor Dr. Zimvo Obasa
Life outside the lab Reading / Casual video gaming / Trying new foods
Shamsuddeen Yusaf Ma'aruf
Investigating the influence of biomimetic nanoparticles on macrophage polarization and their anti- mycobacterial efficacy on polarized macrophages
Supervisor Prof. Samantha Sampson
Co-supervisor Dr. Nelita du Plessis
Life outside the lab Teaching / Fine art / Poetry / Football and long tennis
Identification of genes associated with Mycobacterium smegmatis persister formation
Diana obtained her bachelor's degree in forensic science at Kenyatta University, Kenya, and joined the division in 2023 as a master's student. Her research project seeks to identify genes associated with Mycobacterium smegmatis persister formation using Himar1 transposon mutagenesis. The project will improve our understanding of bacterial persistence and provide possible targets to guide the future development of TB treatment strategies.
Supervisor Dr. Nastassja Kriel
Co-supervisor Prof. Sam Sampson
Life outside the lab A scout / Football (Chelsea) fan / Nature lover
Senior Research Assistant
Caitlyne is an enthusiastic, dedicated and diligent member of the Host-Pathogen Mycobactomics Research Group. She joined the group as an honors student in 2017 and stayed on to complete her Master's degree which she completed in 2019. In 2020, in the midst of a worldwide pandemic, Caitlyne became the Host-Pathogen Mycobactomics "Lab Fairy" and became involved in various aspects of our research environment. She works as the senior research assistant on an NIH-funded research project focussed on investigating nanoparticle-based host-directed therapies for the eradication of Mycobacterium tuberculosis. Caitlyne also plays a vital role in managing the lab in which our group works and is responsible for maintaining a safe, organized and GLP-compliant research environment.
Life outside the lab My son, Kai / being in nature / doing anything active / arts & crafts
Zahn de Bruyn