Interview with Catriona Halliday, mycologist

Dr Catriona Halliday at work in the lab. She doesn't normally sport a red lab coat but I sense a new trend. 

Have you ever considered a career in research? Its an opportunity to influence human and animal health on a broad scale. SAT interviewed scientist Catriona Halliday about her research on pathogenic fungal species. For those who don't know, mycology is the study of fungi - from mushrooms to yeasts used for brewing beer to fungi that cause clinical disease in humans and animals. A mycologist someone who studies fungi. They're also a fun guy to be with (get it? fun-gi!).

At this point I should declare that I have been hosting an Italian mycologist in my house. Thus I've been mixing with more mycologists than your average non-mycologist might normally. But these people are passionate about science and the health of humans and animals. And that is very fortunate for the rest of us: the death toll from serious fungal infections (mycoses) is similar to that of tuberculosis and malaria. But research funding on fungal disease is reasonably poor.

Worldwide, the antifungal drug market is worth around $8billion, and growing by 2-3 per cent per annum, but there are not a huge number of antifungal treatments available and many cause significant side effects and toxicities.

Catriona Halliday is the Senior Scientist in charge of the Clinical Mycology Reference Laboratory at Westmead Hospital where she has been working for over 14 years.  Her research interests have focused on the development and implementation of culture independent tests to aid in the rapid diagnosis of invasive fungal infections, in particular invasive aspergillosis. She took some time out of her very busy schedule to talk to SAT about her career as a scientist and mycologist.

Dr Halliday.

What’s your day job?

I’m the senior scientist in charge of the Clinical Mycology Reference Laboratory at the Centre for Infectious Diseases and Microbiology Laboratory Services (CIDMLs), Pathology West – Institute of Clinical Pathology and Medical Research (ICPMR) at Westmead Hospital in Sydney. Our role is to isolate and identify fungal pathogens directly from clinical specimens using both conventional culture and culture independent methods through the detection of DNA and antigen surrogate markers. 

Additionally, fungal cultures and aerobic actinomycetes (e.g. Nocardia species) are referred to us for identification and/or antifungal susceptibility testing from other pathology services within NSW and interstate. I train medical registrars, undergraduate and postgraduate students in practical and theoretical aspects of medical mycology.

How did you become a professional scientist?

Accidentally – I never knew what I wanted to do but enjoyed biological sciences at school. I knew I wanted to go to the University of Sydney so decided to enrol in a Bachelor of Science degree (a general degree that wasn’t Arts). I loved my time at university, meeting many of my closest friends and gradually the subjects I studied and was interested in narrowed to microbiology. I graduated from my B Sc. (Hons) in 1997 and completed my PhD, also from the University of Sydney, in 2001. Towards the end of my PhD candidature I was fortunate to hear about a new job that had been created in the Mycology Laboratory at Westmead Hospital. The position required experience in both clinical mycology and molecular biology, it was as though it had been written for me! 

Fungal diagnostics is several decades behind diagnostics in bacteriology and virology, and when I began working at Westmead detection and identification of fungi in clinical samples relied completely on culture. My role, when employed at CIDMLS, was to expand my narrow knowledge of culture-based identification of fungal pathogens and to develop PCR-based assays to allow more rapid diagnosis and with the aim of improving patient outcomes.

How did you become interested in mycology?

I completed the first 3 years of my B. Sc. before I was 20.5 years old. Having gone straight to university from school I wanted to take some time off to travel before ‘finding a real job’. Against the advice of some senior lecturers, who thought I would never return, I deferred my candidature and took 12 months off. 

Towards the end of that time, I contacted the Department of Microbiology at Sydney University for a list of honours projects that were being offered for the following year. In my absence, a new lecturer with expertise in mycology had been employed. All 3 of the honours projects I shortlisted were in the Mycology Laboratory under the supervision of Dr Dee Carter. The project I ended up undertaking was titled ‘Analysis of the source of Cryptococcus neoformans var. gattii infection in animals’ and I was co-supervised by Professor Richard Malik [ed - Professor Malik is veterinarian with an interest in mycology]. My interest and love of medical mycology had begun with the support, optimism and enthusiasm of two incredible mentors. Following on from my honours year, I was given the opportunity to enrol in a PhD which was financially supported by an NH& MRC grant of Dee’s.

In your view, which is the most interesting fungal pathogen and why?

Having studied it so intensely for 4.5 years, Cryptococcus gattii will always be close to my heart. The discovery of its association with Eucalypt trees in the early 1990s put Australia and medical mycology on the map. Closer to home, my work on this fungus cemented my career path. Fortunately for the patients, I don’t come across C. gattii too often. My two favourite fungi to look at microscopically are Saksenaea vasiformis, which as the species name suggests looks like a vase and Sporothrix schenckii, whose conidia cluster like the petals of a flower [Ed: click the species names to view the images, and she's absolutely right. I would enlarge and frame that image of Sporothrix schenckii if it were available in high res!].

What do we need to do to prevent or manage these infections?

Provide a rapid, accurate diagnosis and help restore a patients immune system to fight off the infection.

What non-human(s) do you share your life with and how did you meet?

I grew up with pets – a series of black standard poodles and one very special brown Burmese cat, Grizz, who ruled the house. When I moved out of home, I left Grizz behind but as soon as I had settled into a more permanent home, we acquired our ‘first born’ – a brown Burmese called Audrey. Over the years, Audrey’s place in the pecking order has moved down the ladder as we have welcomed 3 human children into the home, but the kids adore her and my youngest of 2.5 years fights to feed her and insists on brushing her if given half the chance. As soon as the kids are in bed and I am relaxing in front of the TV she leaps onto my lap for a pat and some much needed one on one time.

Audrey Halliday, proving yet again (n must equal a gazillion by now) that behind (or on top of) every truly great scientist there is a great cat.

 Any advice for aspiring scientists?

It’s becoming increasingly competitive and difficult to find employment in areas of applied science. I feel so fortunate to have a permanent job doing something I love and hopefully making a difference. My advice to aspiring scientists is to identify your mentors, work with them, and don’t underestimate their importance. 

Although some may view a B. Sc. as a very general degree, it teaches you to think and problem solve in ways that can then be applied to other professions. When applying for jobs, be prepared to start in roles that you may be overqualified for – get your foot in the door, prove yourself and other doors will open.