Traditional microscopy has long been the standard for detecting gastrointestinal parasites, but a DNA-based technique developed at UTS is revolutionising traditional hospital-based pathology processes.
Professor John Ellis
School of Life Sciences,
Faculty of Science
St Vincent’s Hospital
Nausea, vomiting, diarrhea are often the first signs of gastrointestinal illness rearing its ugly head—but identifying the underlying causes can be a tricky proposition, particularly when parasitic infections are to blame.
At St Vincent’s Hospital in Sydney, a new diagnostic test is changing the way pathologists diagnose these infections, leading to more tailored treatments for patients. Based on a longstanding research partnership between the UTS Faculty of Science and St Vincent’s Hospital in Sydney, the testing process was developed as part of PhD project that focused on Dientamoeba fragilis (d. fragilis), a parasite often present in patients with gastrointestinal symptoms.
PhD student Damien Stark, at the time a microbiologist at St Vincent’s, used a technique called the polymerase chain reaction (PCR) method to amplify d. fragilis DNA. While the PCR methodology is used extensively in other areas of science, Stark’s adaptation of the technique for the detection gastrointestinal parasites was unique.
“The standard diagnostic method for these parasites would be to take a faecal sample, spread it on an agar plate and see what grows. Sometimes the samples take a couple of days to grow, and so the use of microscopy in that context is just not efficient,” says UTS Professor John Ellis, who supervised Stark’s PhD.
“With the PCR method, you’ve got a completely different workflow—it’s faster, a robot makes the DNA, and a machine does the PCR. It’s far, far quicker. We also believe there’s something like a 50 per cent failure rate on microscopy, whereas PCR is completely specific.”
The diagnostic capability of Stark’s PCR test was immediately apparent. Ellis, Stark and their team went on to develop a multiplex tool that detects the presence of five gastrointestinal pathogens simultaneously, and a vast new program of research was born.
The UTS team partnered with a range of industry partners to translate the research into clinical practice; currently, they’re working with Sydney-based Genetic Signatures, which builds the robots and the testing kits that use the UTS-developed diagnostic method.
At St Vincent’s Hospital, where Stark is now the senior operations manager in the hospital’s SydPath pathology service, the original UTS multiplex test has been expanded to detect up to 30 pathogens at once.
“We have replaced 10 or more different tests with one multiplex test and that’s led to significant workflow savings,” says Stark, whose team tests more than 6,000 faecal samples a year.
As well as revolutionising hospital workflows, the PCR testing method is also great news for patients.
Professor Kerryn Phelps, a Sydney-based GP and past president of the Australian Medical Association, says the use of PCR testing enables a much more specific and tailored approach to treating patients with gastrointestinal issues.
“I can now, with confidence, order a stool pathogen test and expect an accurate answer. And I can tailor individual treatments specific to the results. I see enormous health benefits to patients, many of whom have been very unwell for a long time,” she says.