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Rheumatic Heart Disease Australia

RHD Resouces

Researcher takes aim at unlocking secrets of Strep A

Dr Tim Barnett became fascinated with Group A Streptococcus as soon as he encountered it as a postdoctoral fellow in Atlanta, Georgia – in a way, it was love at first sight! Now after an academic career so far spanning Australia and the US, he’s working on research much closer to home.

After his undergraduate degree in Perth and a PhD in Hobart, it was whilst undertaking a post doc in America, working with preeminent leaders in Group A Streptococcus genetics, that he became fascinated by how the bacterium could cause such different diseases and in such varied populations.

Now he says the research he’s doing at the Telethon Kids Institute with HOT NORTH funding, is the most professionally satisfying of his career so far.

“My work now, can really make a difference,” he says. When I used to write papers and grants, the real-world outputs were the first few sentences, then it was all about the nitty gritty of science. Now when I write and talk about my work, I feel much more passionate as I really believe that I’m doing something that matters.”

Tim’s research is looking at the skin condition, impetigo, and its complication, acute rheumatic fever (ARF) – an inflammatory illness that can lead to serious complications such as rheumatic heart disease (RHD).

Currently, Australia has among the highest recorded rates of ARF and RHD in the world, and it’s a significant cause of disease among Aboriginal and Torres Strait Islander children. With one in two Aboriginal children having impetigo at any one time, finding a way to better treat impetigo could significantly reduce rates of ARF and RHD in Australia.

Tim is working in parallel with another study that is giving impetigo patients cotrimoxazole (a combination of antibiotics). His research is trying to figure out which genes confer resistance to cotrimoxazole, and then developing methods to rapidly track those genes.

“Until I began studying it, I wasn’t really aware that Group A Streptococcusaffected Aboriginal people. I became fascinated with it for academic reasons and that fulfilled a professional and personal need for a period. But then I thought, what am I doing all this for and who is this helping and what can I do to help?”

The current treatment for impetigo is an intramuscular injection with penicillin – which as Tim explains is a ‘Big, fat needle that hurts”. He goes on; “These are young kids. They see a big needle and run out of the doctor’s room, then once bitten, twice shy. So, the next time they’re infected, they may not want to go back to the doctor.”

His work will provide data that backs up this alternative antibiotic treatment and provides a way to detect and monitor any resistance.

“It’s particularly rewarding to see how my work can improve the lives of disadvantaged people who don’t have good access to healthcare.” He says.

And he’s already seeing some potential results:

“It’s academically very exciting. There’s evidence that, in some cases, the bacteria may be completely resistant to both components of the antibiotics given, but still sensitive to them in combination.”

He explains. “Cotrimoxazole is a short course of oral medicine, which is so much friendlier to young kids, but we want to make sure this antibiotic is usable for as long as possible, so we have to be careful about resistance and ways to detect and monitor it.”

Tim’s also working on identifying what it is about Group A Streptococcus that makes it cause ARF and then using that information to try and develop a better diagnostic test for ARF.

“ARF is hard to diagnose but when a child is diagnosed with it, to prevent them developing rheumatic heart disease, they have to have those big injections every month for at least 10 years, so it’s important to get the diagnosis right.”

Tim’s made some good progress with this too:

“We’ve identified a protein on the Group A Streptococcus surface that’s more common in rheumatic fever strains than non-rheumatic fever associated strains. We’ve looked at genome sequences to figure out why, and will then confirm these findings by looking at the immune responses of rheumatic fever patients. We are waiting for patient recruitment to be finished, but we are making good progress with the computer analysis.”

From a professional perspective Tim says all these opportunities have placed him in an academic area that very few people with his expertise are working on.

“I have a real chance to carve out my own niche in this field, and to work in an area where I can really add some value.”

He says his HOT NORTH fellowship and pilot funding has also put him in contact with brilliant people such as Professors Jonathan Carapetis and Bart Currie and Associate Professor Asha Bowen who have helped him develop his research programs and work through patient recruitment while opening up opportunities to learn more about microbiology.

Tim really loves the work he’s doing and says if he can play his part in closing the gap in inequality that exists between communities in northern Australia and elsewhere, he’ll be very happy.