Professor Jacqui Norris

09 Mar 2020
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The Australian Companion Animal Health Foundation (ACAHF) was founded in 1989 and is a not-for-profit trust of the AVA and is administered through the ASAV office. Its purpose is to support and promote research into the causes, prevention and cure of disease in canine, feline and other companion animal species, especially dogs, cats and other pets relevant to small animal veterinary practice.

The foundation raises money through donations from veterinarians and companies associated with the pet industry, corporate sponsorship and through the ACAHF Memorial Donation Scheme.

Every year, the ACAHF awards grants to deserving companion animal research projects around Australia.

For this edition of Companion, Heather Vaile talks to grant recipient, Dr Jacqui Norris, a professor of veterinary microbiology and infectious diseases at the University of Sydney’s School of Veterinary Science.

Jacqui coordinates the teaching of veterinary microbiology to veterinary students and she enjoys working on practical research projects and education programs for industry professionals, such as vets and companion animal breeders at the university’s Centre for Veterinary Education. She also oversees the microbiology area of the school's Veterinary Pathology Diagnostic Service.

Jacqui’s current research interests include advancing our understanding of the causes, treatment and diagnosis of a number of feline viral diseases (including both domestic and wild felids), such as those caused by: feline infectious peritonitis, feline immunodeficiency virus, feline leukaemia virus and feline calicivirus.

She is likewise interested in determining the aetiology and early detection of kidney disease in domestic cats and wild felids, and passionate about the prevention of canine parvoviral disease; antimicrobial resistance surveillance in animals (including humans); the development and evaluation of antimicrobial stewardship programs in veterinary practice; the epidemiology of the zoonotic bacteria Coxiella burnetii in cats, dogs and wildlife; and the prevention of Q fever in humans.

Since taking up her role at the University of Sydney in 2002, Jacqui has been awarded multiple research grants from the ACAHF, and her projects are focused on practical solutions and applications to assist vets to save many more companion animal lives in the future.

Just to introduce you to our readers, could you tell me a little bit about your current role at the University of Sydney in your own words?

I have a teaching and research position at Sydney University’s School of Veterinary Science and both my teaching and research is in the area of veterinary infectious diseases, so mainly bacteria, viruses and fungi.

Together with colleagues, I teach the veterinary students all the diseases associated with bacteria, viruses and fungi in animals. I’ve got lots of different research areas in infectious diseases as well. I’m associate head of research for the vet school, so I have an overview and strategy role for our school’s research which I love.

Why did you decide to devote your career to teaching and veterinary research rather than working as a GP vet?

I still do a little bit of work as a GP vet but I just love teaching – and infectious diseases is a very exciting and dynamic area – it’s very changeable. I guess I felt that’s where my skill base lay. I love clinical work and the way I teach is focused on clinical relevance and clinical case studies.

Can you tell us a little about your research project called: ‘Vets and their pets: unravelling the transmission cycle of methicillinresistant Staphylococcus species in small animal practice’?

This study followed a larger project with my collaborators from University of Adelaide and Murdoch University. What we did with the much larger Australian Research Council (ARC) Linkage Project was, in a one-year time frame, for any Staphylococcus or E. coli submitted as part of a diagnostic sample from any type of animal was captured and then analysed for antimicrobial resistance – across all animal species. That was in 2013 and involved analysing samples from the 21 diagnostic labs across Australia.

It captured within a year-long timeframe, the extent of antimicrobial resistance in our companion animals and production animals. Fortunately, this showed our Australian animals were doing well in this regard with low levels recorded.

There were actually two projects that the ACAHF funded. We know that MRSP is reasonably common in causing clinical disease but how many animals carry it asymptomatically? That was one project. The second question was, do veterinary personnel and their pets at home carry methicillin-resistant Staphylococcus pseudintermedius (MRSP) or methicillin-resistant Staphylococcus aureus (MRSA), both of which present potential risks to both animals and people?

With my fantastic PhD student at the time, Dr Kate Worthing, and one of our fabulous Doctor of Veterinary Medicine students, Dr Laura Gerber, we looked at a referral hospital and a primary care hospital.

We knew that the carriage rate of MRSP was around about eight per cent. The question around vets and pets and unravelling the transmission cycle was, do our practitioners carry MRSP? We know that they have a higher rate of carriage of MRSA; Professor Darren Trott did an earlier study where we realised that vets can be carriers of MRSA more than the general population.

So the question was, are they carrying this canine one as well?

Staphs can go across species. But Staphylococcus aureus as a general rule, prefers humans as hosts. It depends on the clonal type. With Staphylococcus pseudintermedius, dogs are by far the most common hosts. We do see it occasionally in cats, horses and cattle, and infrequent cases in humans.

Why were you interested in looking at both of these types of infections in particular?

Staphylococcal infections in human and animal health are important and common causes of disease – such as wound infections, urinary tract infections – basically any body systems. They’re fantastic pathogens but they also will live with us as part of our bacterial flora.

We were interested in what’s called the methicillin-resistant Staphylococcus aureus (MRSA). It’s a terrible name, they’re not just methicillin-resistant, they’re resistant to a wide range of penicillins and cephalosporins, or beta-lactams, a really important group of antibiotics used commonly in human and veterinary medicine.

In terms of the vets and pets research, in your opinion, what was the most interesting finding from the research project overall?

We found that none of the veterinary personnel’s dogs or cats carried MRSA, and none of the veterinary personnel carried MRSP. That was a very positive finding.

For the small number of dogs that did carry MRSP, they were different clonal types to the ones we’d discovered in the big national survey. Now we don’t know whether they’re just not as good a pathogen or they have simply not been described in clinical disease before.

At least in this small pilot study, two hospitals which we knew from our previous ACAHF carriage study both had dogs with MRSP carriage at a rate of eight per cent, yet the veterinary personnel in this study were not carrying any MRSP – which is great.

In terms of the dogs and cats at home, only the dogs were carrying MRSP – and they were a totally different strain or clonal type to the ones we’ve seen in clinical disease.

Did the project go straight to plan or were there any hiccups along the way?

It was pretty straightforward. There were just a few logistics things involved – obviously we had to have animal and human ethics. Thanks to Dr Kate Worthing’s hard work, we very quickly worked out a very efficient process for the collection of samples as there were a lot of isolates to deal with from each participant.

Overall, we collected samples from 46 veterinary personnel, 79 personnel-owned dogs and cats, 151 clinically-normal canine hospital admissions and 25 environmental sites.

We had a training session in each clinic because the veterinary personnel had to sample themselves and their dogs and cats at home, in a standardised way, so we were very specific in our instructions.

People were super-happy and willing to cooperate. If they wanted their results, we were able to provide this to them. But if they didn’t want their results, that was fine too. Following that the data was made anonymous so the researchers and subsequently the publication doesn’t identify participants or the participating clinic.

How do you decide on the methodology you used for this project?

We drew on our own experience and the published literature. For example, if you get taken to hospital and you have terrible fractures, they will routinely swab your nasal passages, oral cavity and perineum for MRSA. Because they want to know before they proceed with major surgeries whether or not you carry MRSA. That information is important because it will influence the antibiotics used, the level of barrier nursing while you are in hospital and the risk of major postoperative infections.

We applied the same three areas for dogs and cats. We obviously didn’t ask our veterinary personnel to do all three, we just asked them to swab their nasal passages, which was much more polite!

Did any of the findings from the research surprise you, for example, that the rate of MRS isolation was not significantly different between the samples taken from tertiary referral hospital and the primary accession hospital studied the project?

Yes. I expected the referral hospital to have a higher rate of carriage of MRSA or MRSP because the cases at a referral hospital tend to be more complicated and complex. Usually cases that are going to referral hospitals have had other procedures and other comorbidities, so we were quite surprised that the rate was the same between the two.

Do you have any thoughts or theories about why MRSA is more common among human hospital patients than veterinary hospital patients?

It’s not impossible for a Staphylococcus aureus to cause disease in any animal species, including birds. It has some host adaptive genes where it just prefers humans and is actually more comfortable there, so carriage will remain there longer.

Just to complicate things, there are also livestock-associated MRSAs, where they have a preference for livestock. We don’t seem to have that in our livestock in Australia. We have had some very isolated cases in pigs but as a general rule, we fortunately haven’t experienced the problems in livestock-related MRSA seen in other countries. We have had very different rules around the registration of antibiotics for use in production animal species in Australia for a very long time and this has placed Australia in a favourable situation compared to other places. Most critically important antibiotics are not registered for use in production animal species in Australia and so this has prevented the use of these broad-spectrum antibiotics. In all studies to date in Australia, including our national survey, our production animal species have incredibly low rates of antimicrobial resistance which is great.

Is intra-transmission between pets in multi-pet households something that occurs very often with these types of bugs?

It’s definitely possible. Staph is very good at staying out in the environment for a while. That’s the case too with any person with MRSA. It’s easy to actually spread it amongst the household environment and to other people in the household, through contact with each other or contact with their shared environment.

Fortunately, most of the studies so far that have been done show that MRSP is not a huge fan of humans. It can cause disease and people can carry it, but it’s just not a big fan and that is a big advantage.

Can MRSA and MRSP be spread from dogs to cats as well as from animals to people and vice versa?

Yes, they can, though MRSP is a much bigger fan of dogs. Certainly, in our national study, we found that around 10 per cent of the dogs had MRSP infections.

For cats, their most common species is Staphylococcus felis, and we think that that one actually dominates and probably out-competes the other staphs. That’s a good thing because we don’t see antimicrobial resistance in that species, possibly because it has a fitness cost to carry extra genes for drug resistance. We’ve published a paper on that as well. We occasionally see MRSA, MRSP in cases with cats, but nowhere near the rate of MRSP we see in cases with dogs. We don’t see a lot of MRSA infections in dogs.

How do you hope your MRSA and MRSP infection-transmission research might help companion animal vets and their patients in the future?

We’re certainly interested in doing bigger studies to see whether the risk of transmission is there but we’re also looking at alternative therapies, so looking at bacteriophages, which are viruses of bacteria, so even bacteria have viruses that kill them.

Bacteriophages are used in some specific instances in human medicine to treat intractable infections, where antibiotics won’t work. So we’re doing some preliminary work to see whether there might be some options for use of viruses against these multi-drug resistant bacteria.

What’s next for you in terms of projects in 2020?

In terms of antibiotic use, we’re expanding an online training program to help vets with their antibiotic choices. It’s called the 'Antimicrobial Stewardship in Veterinary Practice' online training program. This is a joint project developed with all the other veterinary schools in Australia and New Zealand. It’s already up on the web but we’re expanding and evaluating it, so that people have more practical resources at their fingertips to make solid decisions about antibiotic choices. Antimicrobial agents are a societal drug that we need to preserve and use only when it’s really needed.

It’s a free training resource and is currently available at vetams.org. There are five modules at the moment but I am now working with Associate Professor Jane Heller and Dr Kellie Thomas from Charles Sturt University to expand it further to include a range of other resources that we are currently building: podcasts, videos, papers and case studies, which we hope will help vets to think about the way they use antibiotics. They are such an important group of drugs in veterinary medicine but we need to make sure they remain effective long term for those patients that truly need them and are not wasted on patients where antibiotics are not really needed. In human and veterinary medicine, we are all trying to reduce the frequency and duration of antibiotic use.

Is there anything else you’d like to mention about your research work?

Yes. I don’t know what I would do without the Australian Companion Animal Health Foundation funding. It has funded so many of my projects and it’s a godsend! There’s very little money from other sources for companion animal research in Australia. You can really complete some significant research project with $10,000 and it makes a huge difference.

It’s a wonderful source of funding for companion animal researchers and it’s really not available at that level elsewhere in Australia.


Jacqui and her research collaborators published their findings about MRSA and MRSP transmission rates in small animal practice in the journal Veterinary Microbiology 223, 79-85 (2018) under the title: Methicillin-resistant staphylococci amongst veterinary personnel, personnel-owned pets, patients and the hospital environment of two small animal veterinary hospitals.

Other related articles from the national study include:

Worthing, K., Abraham, S., Coombs, G., Pang, S., Saputra, S., Jordan, D., Trott, D., Norris, J. (2018). Clonal diversity and geographic distribution of methicillin-resistant Staphylococcus pseudintermedius from Australian animals: Discovery of novel sequence types. Veterinary Microbiology, 213, 58-65.

Worthing, K., Abraham, S., Pang, S., Coombs, G., Saputra, S., Jordan, D., Wong, H., Abraham, R., Trott, D., Norris, J. (2018). Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Isolated from Australian Animals and Veterinarians. Microbial Drug Resistance: Mechanisms Epidemiology and Disease, 24 (2), 203-212.

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