An interview with Meaghan Castledine

October 2020

Meaghan Castledine is a PhD student at the University of Exeter, UK, and a member of the Microbiology Society. In this interview, she tells us more about her research which focuses on phage therapy and why this research is essential in order to develop methods to predict bacteria and phage evolution. 

Meaghan Castledine
© Meaghan Castledine

Tell us a little about your research.

I’m currently a PhD student based at the University of Exeter, where I am lucky to work with Angus Buckling’s lovely research group. The main topic of my PhD research is phage therapy: the use of phage (viruses which infect bacteria) to treat bacterial diseases. In particular, we are trying to understand how bacteria and phage interact within real patients being treated with phage therapy. We know from experiments that bacteria and phage can enter long evolutionary battles in which bacteria can evolve resistance to phage and phage can respond by increasing their infectivity. However, how bacteria and phage interact and evolve in patients is poorly understood. By using controlled laboratory experiments, we can evolve isolates taken from patients and compare these results to evolution which has occurred inside the human body.

Why is this research important?

Phage therapy has gained in popularity now, despite initially being used in the early 1900s, because of antibiotic resistance. Antibiotic resistance is problematic because bacteria can evolve faster than we can discover, manufacture and produce new antibiotics. Whereas, the evolvability of phage means that they could maintain their activity inside patients and can be pre-adapted to kill bacteria even more effectively. In addition, when bacteria evolve resistance to phage, this can cost the bacteria its virulence (the harm it can do to the human patient) and can even prevent or reverse antibiotic resistance. Consequently, we need to develop methods to predict bacteria and phage evolution in patients in order to maximise treatment success.

Why does microbiology matter?

Microbes are the most diverse and adaptable species on our planet, which has placed them at the heart of our lifestyles and ecosystems. By understanding microbes, we can generate solutions to pressing issues from medicine to agriculture and conservation. Additionally, as microbes reproduce and evolve extraordinarily quickly, we can use them as an amazing research tool to understand ecological and evolutionary processes.

Why did you join the Microbiology Society?

In order to tackle pressing microbiological issues, we need to cultivate collaborations and discussions between microbiologists of diverse expertise. For instance, to make phage therapy successful, collaboration between experts including microbiologists, evolutionary biologists and medical researchers is required.  The Microbiology Society acts as a great melting pot where these conversations can happen, and new connections are made.

If you are a member of the Society and would like to find out more about how you can get involved with Society activities and/or showcase your research, please email us at [email protected].