Thesis

Identification and quantification of antibiofilm metabolite extracts using electrochemical techniques

Downloadable Content

Download PDF
Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2024
Thesis identifier
  • T16872
Person Identifier (Local)
  • 201993079
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Currently 2.29% of deaths worldwide are caused by antimicrobial resistance (AMR), this is compared to 1.16% caused by malaria, and 1.55% caused by human immunodeficiency virus and acquired immunodeficiency syndrome (HIV/AIDs). Furthermore, deaths from AMR are projected to increase to more than 10 million per annum by 2050. Bacteria within biofilms have shown resistance to 1000-fold higher concentrations of antibiotics than planktonic cells. This is due to the bacteria entering a dormant-like state, reducing their growth rate. As many antibiotics target mechanisms of active metabolism, these are less effective. New antibiofilm-metabolites are needed to inhibit biofilm formation and target established biofilms. Bacteria from the marine environment are a rich, untapped source of novel bioactive metabolites, many of which have not been tested for antibiofilm properties. However, the current methods of screening for antibiofilm activity and quantification of biofilms are slow, and do not provide crucial information, such as time to eradication. This thesis aims to tap into this rich marine biodiversity. To fulfil this, strains were isolated from Scottish marine sediments, and screened these for their antibiotic and antibiofilm potential. Their metabolites were subsequently extracted and analysed using tandem mass spectrometry to identify the bioactive compound. Alongside this, we aimed to develop a method for biofilm quantification which could be translated into the clinical setting, as well as used in the screening of antibiofilm agents. This was carried out alongside crystal violet staining, as a published point of reference. The developed electrochemical techniques, electrochemical impedance spectroscopy and square wave voltammetry, were able to detect P. aeruginosa biofilm formation within an hour after seeding P. aeruginosa on the sensor. This showed that there was a 40% decrease in impedance modulus when P. aeruginosa biofilm had formed, compared to the media only control. This was also compared to a non-biofilm forming mutant, which showed only a 9% decrease in impedance modulus also compared to the media only control. As such, this thesis offers a starting point for the development of real-time biofilm sensing technologies, which can be translated into implantable materials.
Advisor / supervisor
  • Duncan, Katherine
Resource Type
DOI
Date Created
  • 2023

Relations

Items

Thumbnail Title Date Uploaded Visibility Actions
file details PDF of thesis T16872 2024-07-30 Public Download