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Investigation of in vitro phage therapy with free and encapsulated phage targeting S. aureus infection in human cells

Primary Supervisor: Dr Antonia Sagona, School of Life Sciences

Secondary supervisor: Dr Danish Malik, Chemical Engineering, University of Loughborough & Professor David Roper (SLS)

PhD project title: Investigation of in vitro phage therapy with free and encapsulated phage targeting S. aureus infection in human cells

University of Registration: University of Warwick

Project outline:

Bacteriophages or phages are viruses that can target their host bacteria with great specificity. Due to their small genome, they are excellent tools for genetic engineering 1. The idea of using phages as therapeutics instead ofconventional broad spectrum antibiotics for the treatment/control of bacterial infections is becoming important due to the problem of antimicrobial resistance . Staphyloccoccus aureus is a well known problematic antibiotic resistant bacterial pathogen. It is a traditional gram-positive extracellular pathogen, responsible for skin and respiratory infections and food poisoning, which has also been shown to be capable of invading host cells, including human macrophages 2. The emergence of antibiotic-resistant strains of S. aureus such as methicillin-resistant S. aureus(MRSA), is a major health problem for patients, in combination with the lack of an approved vaccine for S. aureus and this has made the option of phage therapy very attractive 3. In this project, we aim to investigate the invasion of Staphylococcus aureus in different human cell lines as well as the potential to control the infection using S. aureusspecific K phage. Previous data in Sagona lab using different models have been very promising 4. For this purpose, we will use a genetically modified fluorescent phage against Staphylococcus aureus, recently constructed in Sagona lab (unpublished data) as a methodology to detect Staphylococcus aureus infection and localization in human cells linked with the disease caused by the pathogen. We aim to encapsulate the fluorescent phage into liposomes and test the delivery efficacy of the formulated phages compared to free phages targeting Staphylococcus aureus in a human cell environment. Preliminary experiments carried out using free and encapsulated phages in human cells have shown positive results 5. This project is a collaboration between Dr Antonia Sagona, School of Life Sciences, University of Warwick and Dr Danish Malik, Chemical Engineering, University of Loughborough.

The objectives of the project are:

  1. To characterize and optimize the fluorescent bacteriophage against Staphylococcus aureus recently constructed in Sagona lab.
  2. To infect different human cell lines linked to disease caused by the pathogen Staphylococcus aureus and test using regular microbiology methods the ability of the fluorescent phage to clear the infection.
  3. To perform on the above conditions microscopy in order to identify how the fluorescent bacteriophage acts inside human cells.
  4. To encapsulate the fluorescent bacteriophage into liposomes and test its efficacy in clearing infection in human cells.
  5. To perform Electron Microscopy in order to characterize further the encapsulated phage.

The methods to be used in this project are the following: Synthetic biology, molecular biology, microbiology, cell biology, confocal microscopy, electron microscopy, tissue cell culture and biochemistry and phage encapsulation.


  1. Sagona, A. P., Grigonyte, A. M., MacDonald, P. R. & Jaramillo, A. Genetically modified bacteriophages. Integr Biol (Camb) 8, 465-474, doi:10.1039/c5ib00267b (2016).
  2. Cohen, T. S. et al. S. aureus Evades Macrophage Killing through NLRP3-Dependent Effects on Mitochondrial Trafficking. Cell Rep 22, 2431-2441, doi:10.1016/j.celrep.2018.02.027 (2018).
  3. Ajuebor, J. et al. Comparison of Staphylococcus Phage K with Close Phage Relatives Commonly Employed in Phage Therapeutics. Antibiotics (Basel) 7, doi:10.3390/antibiotics7020037 (2018).
  4. Moller-Olsen, C., Ho, S. F. S., Shukla, R. D., Feher, T. & Sagona, A. P. Engineered K1F bacteriophages kill intracellular Escherichia coli K1 in human epithelial cells. Sci Rep 8, 17559, doi:10.1038/s41598-018-35859-6 (2018).
  5. Vinner, G. K., Richards, K., Leppanen, M., Sagona, A. P. & Malik, D. J. Microencapsulation of Enteric Bacteriophages in a pH-Responsive Solid Oral Dosage Formulation Using a Scalable Membrane Emulsification Process. Pharmaceutics 11, doi:10.3390/pharmaceutics11090475 (2019).

BBSRC Strategic Research Priority: Understanding the rule of life: Microbiology

Techniques that will be undertaken during the project:

The methods to be used in this project are the following:

  • Synthetic biology
  • Molecular biology
  • Microbiology
  • Cell biology
  • Confocal microscopy
  • Electron microscopy
  • Tissue cell culture
  • Biochemistry and phage encapsulation

Contact: Dr Antonia Sagona, University of Warwick