Saudi Cultural Missions Theses & Dissertations
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Item Restricted Characterisation of a bacteriophage-based DNA delivery system coupled with an endosomal escape peptide and a cationic polymer for use in cancer vaccines(Saudi Digital Library, 2025) Alahmadi, Dana; Hajitou, AminCancer immunotherapy has recently gained popularity over traditional cancer treatment by harnessing the immune system to eradicate tumours. Therapeutic cancer vaccines represent one example of cancer immunotherapy, with DNA vaccines taking centre stage due to their ease of production and genetic modification. However, limitations in efficient DNA vaccine delivery have opened the door to investigating novel delivery platforms. One such delivery platform is the novel transmorphic phage/adeno-associated virus (TPA) particle. TPA is a hybrid vector of a recombinant adeno-associated virus DNA packaged with M13 bacteriophage capsid proteins and modified with the RGD4C peptide for tumour-targeted delivery. This study aims to characterises a novel TPA particle coupled with the endosomal escape H5WYG peptide and complexed with polyethyleneimine (PEI) (H5WYG.TPA.PEI) to evaluate their synergistic effects on gene delivery for use in cancer DNA vaccines. The safety and selectivity of this complex was determined by measuring lactate dehydrogenase (LDH) levels in sera of immunised mice and by evaluating the tumour-specific transgene expression in tumour bearing mice in vivo. This was followed by assessment of gene expression in tumour and dendritic cell lines using H5WYG.TPA.PEI particles encoding the luciferase reporter gene in vitro. Also, delivery of the H5WYG.TPA.PEI particles encoding model antigenic genes such as the SARS-CoV-2 spike (S) transgene or the human papillomavirus (HPV) L1 transgene were assessed for effective DNA delivery to the nucleus of the tumour and dendritic cells by quantitative polymerase chain reaction (qPCR). The H5WYG.TPA.PEI complex (30 ng/ug PEI) demonstrated a good safety profile and resulted in tumour- specific transgene expression in tumour-bearing mice in vivo. Moreover, it showed enhanced gene expression, enhanced nuclear DNA delivery in tumour and dendritic cell lines in vitro. Overall, this proof- of-concept study highlights the promise of the H5WYG.TPA.PEI complex (30 ng/ug) as a delivery platform for DNA cancer vaccine, especially in effective gene delivery to dendritic cells, which has not been shown before using M13 bacteriophage or TPA particles, opening the door for further investigation of the therapeutic efficacy of this cancer vaccine in eradicating tumours in cancer mouse models.16 0Item Restricted Isolation and characterization of bacteriophage in Providencia rettgeri.(University of Manchester, 2024) Albalawi, Hind Faleh; Hargreaves, KatP. rettgeri is a gram-negative bacterium and a member of the Enterobacteriaceae family. It. an opportunistic pathogen, which can cause many infections but primarily urinary tract infections and is commonly associated with hospital-acquired infections. This bacterium is part of the natural microbiome found in the human gut. Also, is a ubiquitous bacterium that can be found in water sources, soil, and animals. The emergence of resistance in antibiotics in particular carbapenem is a significant concern. Also, it plays a role in the dissemination of this resistance across the world. Therefore, the exploration of alternative therapies is required. One of the most promising alternative therapies is bacteriophages. Hence, this study aims to isolate and characterize bacteriophages that target Providencia rettgeri. 12 environmental samples were collected from the outskirts of Manchester to isolate phages. In addition, bioinformatic tools analysis was used to predict and highlight the role of prophage in the bacteria genome. However, there were some challenges such as Phage induction and failure of phage propagation therefore, understanding and exploiting the P. rettgeri defence mechanism against phages is critical for further research.20 0Item Restricted Using phages to Treat Urinary Tract Infections: Predicting phage susceptibility using bacterial genome and MALDI-TOF data(Saudi Digital Library, 2023-09-07) Alghamdi, Sara; Clokie, MarthaAMR, and MDR present substantial challenges for individuals and have also become a global concern. This has resulted in these infections, gaining increasing attention. Bacteriophages have become the go-to in dealing with bacteria resistance and decreasing the number of mortalities. For this project, instruments like the bacteria genome sequence and MALDI-TOF data will be used to gain predictions of phage susceptibility and serotypes. A group of 16 phages was collected in the lab with at least one manufactured host. This project obtained 70 clinical strains from the Bristol University Hospital. Two techniques were employed in this project: spot test and plague essay. Both methods seek to measure the concentration of the bacteriophage and evaluate the virus’ effectiveness. The serotypes included in this study are ST131, ST69, ST73, and ST95. The project concluded, the gene pattern of ST131 responds weakly to most phages and all concentrations. ST73_35 was the most sensitive in 108=114, 106=87 104=51. Some strains were more sensitive than the others ST73 and ST95 this is may allow to make predictions in terms of family species or sequencing. On the other hand, ST131 was the most resistance strain and then ST69, this would make more challenging to work for phage predictor. It can be noted that JK08 performing the best with strains. On the other hand, the worst phage UP15 1×104 shows more resistance to strain. In the event that further studies with Whole Genome Sequencing and MALDI-TOF were conducted to confirm this mechanism, so that would be able to predict some genes responsible for susceptibility or resistance. The outcome of this project will demonstrate a platform of a broad collection of E. coli strains that might finds the correlation of sequence types with MALDI-TOF and WGS data so we can make predictions on host range.34 0Item Restricted Phages as Deodorants(Saudi Digital Library, 2023-09-07) Asiri, Sami Mohammed M; Galyov, EdAlthough sweat from sweat glands is odourless, anaerobic bacteria from the genus Corynebacterium, Propionibacterium, Staphylococcus, and Micrococcus, which colonise human skin, especially in the armpit, generate chemical compounds when they metabolise sweat. This gives sweat an unpleasant odour, a problem to which deodorants are the most common solution. However, deodorants may cause irritation for some users and have an adverse impact on the skin. Alternative methods offer hope for sweat malodour. For instance, phages and their gene products may eliminate odour-causing bacteria as an alternative to chemical-based deodorants. This project examined the hypothesis that phages could provide an alternative to conventional deodorants by eliminating the bacteria that cause body odour. Specifically, the aim was to isolate the bacteria that cause odour and the phages that could infect them. The methodology involved normal microbiology and phage biology techniques, wherein the isolated bacteria were identified, and the isolated phages were characterised. Twelve anaerobic bacteria were isolated from human skin samples and identified by Autof MS1000 MALDI-Tof. A specific phage, termed Phage S, was also isolated from the human epidermis, and its lytic activity against Staphylococcus cohnii isolates was demonstrated. The maximum lytic activity of Phage S was observed between 35 and 37°C, and the optimal storage temperature was 4°C. Phage S showed a high burst size with a short latent period. In addition, it effectively inhibited bacterial growth as measured by a killing curve assay. The properties and efficient microbial growth suppression of Phage S against Staphylococcus cohnii indicate its potential for phage therapy against odour-causing bacteria.34 0