Project: Training phages against mixed species biofilms

Challenge Space

Health - Resistance 

Principal Investigator(s) and team names

Dr Gaetan Thilliez, Dr Linda Holland

Collaborating Institutions

Funding support 

Project start date

January 2026

End date

Current

Problem

Antimicrobial resistance is on the rise, limiting the treatment options for bacterial infections. 

In 2021 alone, 1.14 millions deaths were directly attributable to resistance to antibiotics, and some predictions put this number to 10 million per year by 2050 if nothing is done. 

Background

Antibiotics are used for treatment of bacterial infections. 

In response to this selection pressure, bacteria can evolve resistance by the acquisition of new genes or mutations. Once acquired, the resistance usually spread within the bacterial population at a rate that outpaces the discovery of new antibiotics. 

Regulating and managing the use of antibiotics are crucial to slow down the emergence and spread of resistance, however the development of new treatment options is also critical. This includes new antibiotics, enzymes and viruses that can only infect bacteria called bacteriophages. 

Staphylococcus aureus is a bacteria of particular interest as it can cause life threatening infection and is known to have acquired resistance to multiple classes of antibiotics. As such, finding new treatment tailored to the strains circulating in Ireland is the focus of this project.

Solution

Bacteriophages are a promising alternative to antibiotics, as they are abundant, diverse, specific to their host, leaving the healthy microbiota intact. 

However this specificity is also a drawback, as the number of strains a phage can infect are typically limited. In this project, we are studying the population of the bacterial pathogen Staphylococcus aureus to understand the diversity present in Ireland. 

During infection Staphylococcus often form single and multi-species biofilm. Our team is isolating phages that can infect clinical strains of Staphylococcus find in Irish patients, even when protected by biofilm. By using sequencing we can characterise the new phages, and through targeted evolution, we make the phages better 

at penetrating biofilms and lysing the clinical S. aureus in conditions relevant to infection