School of Biosciences

Sawtell coastline, NSW, Australia

Developing and Future Research

At Cardiff it is my intention to continue to expand my co-infection biology research within three key project areas.

1. Gut helminth immune interactions

This is a continuation of ongoing work, in collaboration with colleagues at CSIRO Livestock Industries, in Australia, the University of Liverpool and the University of Bristol. In this work we explore the mechanism of gut helminth interactions in sheep and rabbits and model this system in order to predict the consequences of the parasite interactions for a range of pathogen control systems.

2. Functional Group Interactions

Merino sheep with lamb, Australia

This is an approach aimed at finding a mechanism to systematically deal with co-infections, which would otherwise be of unknown outcome. The aim is to define pathogens not by species or type (e.g. virus, bacteria) but rather by their effects upon and responses to the host immune system in single infections. The relationships between these groups in mixed infections will then be predicted from the known interactions of different elements of the host immune system.

3. Evolution of immunity and virulence

The majority of co-evolutionary studies of host-pathogen relationships have been theoretical and / or focused on single species pathogen infections. In new research at Cardiff I will combine empirical studies with statistical and mathematical modelling to explore the effects of multiple pathogens upon both host and pathogen life-history traits. These dynamics will be examined in a free-running cockroach-host system.

Background

Blue soldier crabs, Sawtell, NSW, Australia

I started out my biological career as a medical microbiology technician at Liverpool Public Health Laboratories but soon decided to return to education, graduating from Liverpool John Moore's University with a degree in Applied Biology. I then spent several years pursuing research interests in red and grey squirrel ecology, behaviour and parasitology, with funding support from the British Ecological Society’s small grants program and from Lancashire Wildlife Trust, through Heritage Lottery funding.

In December of 1999 I began a PhD with Prof Peter Hudson at Stirling University, entitled “The community ecology of wild rabbit (Oryctolagus cuniculus) parasites”, completing that in June 2003. Upon completion I was offered the position of Research Scientist with the Commonwealth Scientific and Industrial Research Organisation’s (CSIRO) Division of Livestock Industries in Armidale, New South Wales, Australia. I started work at CSIRO in August 2003, in the role of epidemiologist / modeller. At CSIRO I built a research group examining pathogen interactions, a research focus begun during my PhD. Finally, in July of 2006 I was interviewed here at Cardiff and began work within the Biodiversity group at the beginning of October.

My interest in co-infection started during my PhD where, thanks to the phenomenal 23 year data set of rabbit parasites, collected by my colleague Dr Brian Boag, I was able to find compelling evidence for interactions between the five gut helminths in this system. This was the first consistent evidence of inter-specific pathogen interactions, from a wild host system, to be reported in the literature.

Our hypothesis for the mechanism of interaction between several of these helminths was that they were mediated through the host immune system. Unfortunately, in the span of the PhD I was not able to test this hypothesis. However, the sheep and the rabbit both have similar helminth gut communities. Therefore, when CSIRO beckoned and offered a potential opportunity for me to experimentally test, in the sheep system, some of the hypotheses formulated on rabbits, I grabbed my opportunity.

Gaining a complex systems science grant shortly after arriving at CSIRO I was able to set up a small co-infection research group, to explore the interaction between three common sheep gut helminth species. The final laboratory stage of this work is currently underway in Australia. Preliminary analyses show that interactions are certainly apparent in this system too and that they may be mediated through host immunity.

The group utilises cross-disciplinary approaches to elucidate the system. My collaborators (Prof Mark Viney - University of Bristol, UK; Dr Andrew Fenton - University of Liverpool, UK; and Dr Susan McClure - CSIRO Livestock Industries) and I, combine mathematics, experimental parasitology, immunology and ecology to elucidate the presence, cause and consequences of the interactions. We are applying agent-based modelling approaches in order to predict the effects of interactions on the dynamics of the parasites and their host. Such approaches not only allow us to consider the ecological and evolutionary consequences of interactions, but also enable us to consider more practical concerns. Helminth parasites are a major source of production loss and animal welfare issues worldwide and where once a simple dose of anthelmintics overcame this problem, increasingly these parasites are showing resistance to the traditional chemical interventions. Alternative therapies are constantly being sought. The modelling approaches allow us to examine the consequences of interventions, e.g. vaccination, in terms of their effects on the whole gut community.

Additional Research Interests

More generally my interests lie in the application of ecological concepts, complex systems science ( CSS) approaches and mathematical and statistical modelling techniques to a wide range of biological fields including pathogen biology, immune function and community and behavioural ecology. I am interested in understanding and predicting the relationships between the component parts of systems.

Times series of rabbits and gut parasites

General Philosophy

During my PhD I found myself (thanks to excellent support and teaching) moving from a position of fear and loathing of statistics and mathematical modelling, over to a more enlightened position of interest and developing understanding. I began to believe that statistics could be more than a frightening but necessary evil and become something not only helpful but even interesting. This became even more apparent to me with mathematical modelling, as I discovered how useful models could be for trialling and refining hypotheses and for informing theory. This change of perspective was such a revelation to me that I now have a real passion for helping others (particularly students) to see these fields in a similar light.