Edze Westra 

edze westra

Principal Investigator

After my PhD in the lab of Prof. John van der Oost at Wageningen University on the molecular mechanism and regulation of CRISPR-Cas immune systems (2009-2013), I started to explore the evolutionary ecology of CRISPR-Cas immune systems as a Marie-Curie Fellow in the lab of Prof. Angus Buckling, University of Exeter (2013-2015). I received a NERC Independent Research Fellowship in 2015 to set up my own lab at the University of Exeter, and received further funding from BBSRC, Wellcome Trust and ERC. Details of the ongoing projects can be found below.

Bridget Watson


Post-doctoral Fellow

My PhD research (University of Otago, New Zealand) focused on understanding the influence of CRISPR-Cas on phage-bacteria interactions. I am now looking at the effect of different ecological conditions on the coevolution of CRISPR-Cas immunity and phages, to understand in which environments CRISPR-Cas immunity is most beneficial.

Twitter: @drbridgetwatson

Tatiana Dimitriu

Post-doctoral Fellow

I’m interested in bacterial evolution, particularly coevolution with mobile genetic elements. My PhD focused on understanding horizontal gene transfer from a social evolution perspective, using modelling and experiments using synthetic bacterial strains. I then used experimental evolution to improve the efficacy of Bacillus thuringiensis, a biocontrol species which virulence is mostly based on social behaviours. I am now investigating how antibiotics can affect bacterial coevolution with phages, and restriction-modification defences.

Iolanda Domingues

Post-doctoral Fellow

My PhD research (Evolutionary Biology, University of Lisbon) focused on the ecology and evolution of indirect antibiotic resistance, mediated by conjugative plasmids. Now, I am interested in studying CRISPR-mediated choosiness of bacteria. Specifically, I want to understand in which conditions can a bacterial host selectively associate with certain mobile genetic elements, while resisting others.

Sean Meaden


Post-doctoral Researcher

Sean’s research aims to understand the ecological and evolutionary drivers of CRISPR immunity in bacterial populations. He uses a combination of experimental evolution and population genomics to understand the costs and benefits of CRISPR. Previous research included genomics of an insect-virus system and his PhD focused both on the role of phages in the evolution of a plant pathogen and microbiome shifts during tree disease. Sean is currently a Marie Skłodowska-Curie Actions (MSCA) Research Fellow on secondment at the University of Otago with Peter Finerran’s lab  focusing on the abortive infection mechanisms.

Twitter: @SeanMeaden

Ellie Pursey


PhD Researcher

My project focuses on the removal of antimicrobial resistance genes from bacterial communities found in the human gut, using CRISPR-Cas9 gene editing. For this, I am focusing on clinically relevant vancomycin-resistant enterococci, as well as multidrug resistant Enterobacteriaceae. I am primarily supervised by Stineke van Houte in the van Houte lab group, and co-supervised by Edze Westra and Will Gaze (University of Exeter Medical School).

Twitter: @ElliePursey

Alice Maestri


PhD Researcher

In my project I am analysing aspects of phage-bacteria dynamics, with a specific focus on CRISPR-Cas type I-E of Pseudomonas aeruginosa. I am investigating its evolution under different ecological conditions, as well as the role of prophages in superinfection exclusion and the function of other host resistance mechanisms in determining the outcome of phage infection. Previous research encompassed phage isolation and characterization for therapy purposes against Vibrio cholerae.

Josie Elliott

Josie Elliott_profile

PhD researcher

I am a BBSRC SWBio DTP funded student co-supervised by Dr Tiffany Taylor at the University of Bath and Dr Edze Westra. My project is investigating the evolutionary consequences for fitness and transcriptional regulation after horizontal gene transfer of CRISPR-Cas genes between Pseudomonas species of bacteria. 

Devi Whittle


Technician/Administrative Support

I work part-time for Prof. Edze Westra’s research group. My role is to assist in lab management and administrative duties. I have a PhD in evolutionary biology and I previously worked on a project studying human cultural evolution. I also work with Innovation, Impact and Business supporting innovative research and business development in the agri-food sector. I have a background in adult general nursing. My role with this group is funded by the European Research Council (ERC).

Twitter: @ExeterMicrobes

Matthew Chisnall

Post-doctoral Fellow

My work is focused on understanding how prokaryotic argonaute proteins contribute to the fitness of bacteria.

Rafael da silva custodio

I am interested in microbe-microbe interactions and human pathogen evolution and ecology in polymicrobial environments.  Now at Westra lab, I am working on the interspecific interactions between lung pathogens and how they drive the evolution of CRISPR-based immunity against bacteriophages in the pathogen Pseudomonas aeruginosa. Previously, I worked on the impact of commensal bacteria in preventing colonisation of human cells by the pathogen Neisseria meningitidis and the role of Type VI Secretion System in these antagonistic interactions.