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Professor Mark Stevens on bacterial disease

Bacterial disease in animals and people, his role as Deputy Director for Research and some of life’s professional challenges.

Professor Mark Stevens is Deputy Director for Research at The Roslin Institute and runs a laboratory that studies bacterial diseases, both in animals and that can be transmitted from animals to people – known as zoonoses.

In this interview with Science Communication Intern Maggie Szymanska, he speaks about his work, what he enjoys the most about it and the challenges he has faced.

Mark Stevens’ research group at The Roslin Institute
Mark Stevens’ research group at The Roslin Institute

Could you tell me about your work here?

I have two main roles here at The Roslin Institute.

The first is as an independent researcher. I run a laboratory that studies animal and zoonotic bacterial diseases, in particular foodborne disease caused by bacteria such as Salmonella, E. coli and Campylobacter. These are often found in farmed animals and they can transmit through the food chain and the farm environment to people where they cause diarrhoea. Some types of these bugs can also cause disease in animals. We study the contribution of bacterial and host factors to colonisation of farm animals by these organisms, and use the information to devise strategies to prevent animal disease and the transmission of infections to people.

The second role I have is as Deputy Director for Research. For four years now I’ve been looking after strategic investments at The Roslin Institute. We receive a grant from the UK Government’s Biotechnology and Biological Sciences Research Council (BBSRC), which is renewed every five years. The award that we received most recently in 2017 was of about 32 million pounds, so it’s a huge investment in our science, people and infrastructure. It was my role, with the then Director and senior scientists at Roslin, to bring together the Institute submission and defend it. Now that the grant has been awarded, my role is to work with the programme leaders to make sure that our research stays on track and delivers benefits to animals and society.

What do you enjoy the most about your research?

I feel passionately about studying harmful bacteria in the animals where they are a problem. A lot of published research on pathogenic microbes relies on cultured cells or surrogate rodent models. At Roslin, we are fortunate to be able to study infections in farm animals, where we sometimes make discoveries that were not found in laboratory-based work. I think this helps to inform the design of more effective control strategies.

One of the things that I really enjoy is to devise ways of answering my scientific questions with minimal use of animals or with minimal suffering of animals in research. These are sometimes called 3R approaches, because the aim is to Reduce, Refine or Replace animals in research.

Over the years, I’ve worked on a number of ways to try to reduce the use of animals in our research.

We have devised surgical models where, under anaesthesia, we could study how multiple bacteria strains behave in a single animal instead of having to use multiple animals, each with a separate isolate.

We’ve used clever genetic approaches to assign roles to hundreds of bacterial genes in a single animal, rather than having to test the role of each gene in a separate animal. As a bug like Salmonella has around 4500 different genes, this substantially reduces the number of animals required to understand the function of genes during infection.

More recently, we adapted this approach to be able to follow what happens to large numbers of wild Salmonella strains in a single animal. This is helping us to understand the risk posed by different Salmonella strains, without having to test them one-by-one in animals. 

Mark Stevens’ research group at The Roslin Institute
Mark Stevens’ research group at The Roslin Institute

Could you tell me about a challenge you may have faced in your career?

A big challenge for me, back in 2011, was to start all over again after my team at the Institute for Animal Health was dispersed. I had worked there for 12 years and had a productive group of talented researchers, but the Institute changed its science strategy and stopped working on bacteria and parasites. It was a sad end to my time there, but I moved to Roslin in 2011 and quickly found my feet again.

Roslin has been a great enabler for me, there are so many talented people to collaborate with and I’ve been fortunate to recruit some great postgraduate students and postdoctoral researchers to my team.

What are the advantages of working at The Roslin Institute?

The expertise and infrastructure here at Easter Bush is genuinely world class. When I moved here, my research had mostly focused on the role of bacterial factors in disease. At Roslin, I was quickly able to work with researchers on the role of host factors, in particular to understand the basis of resistance of chickens to bacteria.

The same applies to immunology, where I’ve been fortunate to establish strong collaborations with others developing vaccines, where they have a better understanding of the immune system than me. I benefit greatly from the Institute offering diverse expertise, and BBSRC’s strategic investment is vital to sustain that. It’s one of the reasons I accepted the role of Research Director in 2015.

My final question is, if you weren’t a scientist, what would you be?

As a teenager I had wanted to be a doctor, but I was a little distracted back then and my early academic performance fell short. I was lucky to get a place to study Microbiology & Virology at university, and from that grew an enthusiasm for science that lasts to this day. It’s a pity I don’t often get into my lab coat these days!

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