The Ensilication of Bacteriophages

  • Matt Slade

Student thesis: Doctoral ThesisPhD

Abstract

Anti-microbial resistance (AMR) is a significant problem, resulting in a huge
number of deaths each year. One of the primary forces in the rise of AMR is the
overuse and misuse of chemical antibiotics. Bacteriophages are one potential
alternative antimicrobials that offer a range of benefits such as their ability to
mutate and defeat resistant strains of bacteria. However, as biological entities
these phages often suffer from poor thermal stability, denaturing and becoming
useless after short periods at temperatures above °8 C. Consequently, they
require constant refrigeration during their storage and transport.
During the course of this project, ensilication, a previously developed
method, was investigated for its application in the preservation and stabilisation
of bacteriophages. The successful application to phages would mean they
could be stored and transported at ambient temperatures, allowing for their
easier adoption as alternatives to traditional antibiotics. Ensilication is a
silica sol-gel process, the precursor molecule, tetra-ethyl ortho-silicate (TEOS)
creates polymer molecules that can deposit onto the surface of a peptide based
biomolecule, forming a rigid shell around the molecule. The resulting
particle precipitates out of solution and is transported and stored as a dry
powder, where the silica shell protects the encased entity from unfavourable
temperatures. When required, the silica shell can be chemically broken-down
safely releasing the molecule and allowing it to function as normal.
Two bacteriophages, K and MS2, were used for the ensilication of phages.
A combination of physical, structural, and biological methods was used to
characterise the native, ensilicated, and released bacteriophage molecules,
including in situ electron microscopy imaging of the ensilication process. Both
the ensilicated and native molecules were subjected to high temperatures for
short periods of time as well as ambient conditions for extended periods of
time. The results of this investigation show that ensilication is able to protect
the phages with varying degrees of success. With further work to optimise the
process, ensilication could see real world use as a phage stabilisation method.
Date of Award22 Jun 2022
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorAsel Sartbaeva (Supervisor), Jean Van Den Elsen (Supervisor) & Francoise Koumanov (Supervisor)

Keywords

  • Bacteriophages
  • Phages
  • Bacteriophage
  • Phage
  • Phage Therapy
  • Ensilication
  • Sol-gel
  • Thermal stability
  • Silica
  • Bacteriophage K
  • Phage K
  • Bacteriophage MS2
  • Phage MS2
  • MS2

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