Additionally, chlamydia is a zoonotic pathogen (can be transmitted between animals and humans), posing a considerable occupational health risk to workers in the industry.

Currently, the gold standard for screening these infections is nucleic acid testing (qPCR assays) that detect DNA. These tests are performed by experienced staff in $25-30,000 thermal cyclers in well-equipped veterinary diagnostic laboratories, taking between three to seven days to deliver results.

Our Molecular Chlamydia team in UniSC's Centre for Bioinnovation (CBI), led by Dr Martina Jelocnik, has developed isothermal assays to detect both chlamydia and equine herpes, leading to improvements in the testing process and mitigating the impact of these infections on the Australian Thoroughbred horse breeding industry.

Isothermal testing is run at a single temperature and gives clear results indicating presence or absence of a pathogen DNA, thereby providing an easier and faster screening method.

Our team has developed isothermal testing assays for chlamydia, the first of their kind, complementing existing tests of this type for equine pathogens like hendra and equine herpes virus, equine streptococci, and enteric bacteria.

The advantage of this type of testing is that it can be used at point-of-care with portable equipment and minimal sample preparation, providing same-day results and enabling timely management of infected animals.

CBI’s Molecular Chlamydia team built on their successful 2017 pilot study to develop, validate, and evaluate new rapid isothermal nucleic acid tests for chlamydia and equine herpes in 2018. These tests reduced the time for testing from days to 30 minutes, require minimal sample preparation, and only need basic equipment such as a heating block or real-time fluorometer.

Our new chlamydia and EHV-1 isothermal assays showed high sensitivity and specificity, comparable to reference qPCR assays. When testing rapidly processed clinical samples, the congruence between isothermal assays and qPCR assays was also high.

After promising R&D lab results, further testing was performed in the Scone Equine Hospital laboratory in NSW by technicians without prior molecular experience. The isothermal assays were easy to setup using general lab equipment, with an initial ‘one-off’ setup cost.

Isothermal assays were estimated to cost $15/sample, in comparison to the costs of $90/sample in veterinary diagnostic laboratories.

Brief training was provided, and technicians were able to process and test up to eight samples in 60-90 minutes. One lab manager of a stud who used the new test said, “Your informative support and guidance is greatly appreciated, we have set the isothermal testing with ease.”

This study demonstrated reliability of point-of-care isothermal diagnostics for detecting chlamydia and EHV-1 in the equine industry. This project has also formed a nexus between research, industry, and producers by connections, linking farmers to research and state veterinary diagnostics teams to facilitate access to information. Reaching around 2,000 stakeholders in equine health and infectious disease including breeders, stud managers, and veterinary professionals.

Our new tests have been adopted and independently performed by staff at the Scone Equine Hospital, ACE veterinary laboratory and by a laboratory team on a stud in Hunter Valley, NSW.

In 2021, a laboratory team on a stud used the new isothermal test for chlamydia on more than 30 samples taken from mares experiencing foal loss, aborted material, and their contact mares.

Chlamydia was detected the same day in the two aborting mares and aborted material, while contact mares were tested negative. The same day diagnosis allowed for immediate animal management and alerted the stud team to biosecurity risks associated with chlamydia.

Direct benefits of the translation of our research into rapid diagnostic tests include same day diagnosis, timely management of infected animals such as veterinary care and advice to affected breeders, and significant reduction in testing and logistics costs.

Where current tests take between three to seven days and cost $90 per sample our new isothermal assay testing is about $15 per sample (due to reduced labour, reagents, and logistics costs) and results are delivered in 30 minutes.

Preliminary testing at the Scone Equine Hospital showed a saving of about $50 per sample with results delivered within the hour. The stud team in the Hunter Valley performed five times the number of tests and saved about $60 per sample. The ACE veterinary laboratory has just started testing and has already reporting a significant time reduction.

A livestock vet, on the Sunshine Coast has commented, “I like how quickly you can get the result, so I know what I am dealing with. It is very useful to know to exclude pathogens such as chlamydia. I hope this method gets used more.”