Method development for the in situ screening of uncultivable bacteria for antibiotic production
File(s)
Author(s)
Hansen, Daniel Bilcher Holst
Type
Thesis
Abstract
Multidrug-resistant bacteria are one of the most critical threats facing human health. Despite an urgent need for novel treatments, antibiotic discovery has stalled. Consequently, no novel antibiotic class has been discovered in the last 40 years. Most existing antibiotics were discovered by screening the 1 % of bacteria that can be cultivated in standard laboratory conditions. The 99 % residual bacteria represent a bioresource that could yield novel antibiotics; but at present this bioresource remains largely unscreened. Here I present the development of a novel high throughput in situ screening array (“ISSA” platform), which screens soil bacteria for antibiotic production in their native environment. The developed platform can isolate a known number of soil strains and screen them against specific clinically relevant pathogens. The platform consists of 4080 discrete compartments, with each compartment containing an average of one soil bacterium and an adjacent luxCDABE bioreporter strain that turns off when antibacterial compounds are secreted. The in situ incubation in the ISSA platform significantly boosts cultivation rates of previously uncultivable bacteria, resulting in the isolation and cultivation of novel bacterial strains. The ISSA platform overall leads to an efficient identification process of soil bacteria that secrete antibacterial compounds. So far, the platform has identified seven antibacterial compound producing strains. Three of these strains are novel antibacterial compound producers, which demonstrates that the developed ISSA platform can be a valuable tool in the race to discover novel antibiotics.
Version
Open Access
Date Issued
2018-12
Date Awarded
2019-05
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Low, Harry
Buck, Martin
Publisher Department
Life Sciences
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)