New koala research seeks chlamydia hotspots and risk factors

University of the Sunshine Coast
University of the Sunshine Coast researchers will develop a frontline tool to diagnose chlamydia risk factors in koalas and use detection dogs to seek out chlamydia hotspots.

Two UniSC research projects will share almost $200,000 from the latest round of the Queensland Government’s Community Sustainability Action Grants for Koala Applied Research in South East Queensland.

The first project, in partnership with Australia Zoo Wildlife Hospital, aims to develop a new, simple diagnostic test to identify koalas that are more susceptible to developing chlamydial disease, with the aim of reducing unnecessary antibiotic treatments.

“Identifying predictors of a koala’s risk for chlamydial disease is critical,” said Dr Sam Phillips, from UniSC’s Chlamydia Research Team, who has co-developed a koala vaccine as part of ongoing efforts to stop the rapid spread of the devastating infection.

“Not all infected koalas show symptoms or will go on to develop disease however, at the moment, most koalas that test positive to the sexually transmitted infection are treated with antibiotics.

“Unfortunately, antibiotics can disrupt the koala’s microbiome, which the animal depends on to digest eucalypt leaves, leading to starvation and occasionally death.

“For example, in 2022, 178 koalas were admitted to the Wildlife Hospital for the disease – only 48 of which were re-released. Of the many causes for koala mortality, gastrointestinal dysbiosis from antibiotic treatment was a common cause of death.”

The project will assess samples from more than 1,000 koalas admitted to Australia Zoo Wildlife Hospital over two years.

Dr Phillips said previous studies had found six different risk factors, including the DNA load of chlamydia and koala retrovirus, which made koalas more prone to the disease progressing and leading to symptoms such as blindness, severe bladder inflammation, infertility and death.

“Testing to see if koalas are positive for one or more of these genetic subtypes is complex, so it’s currently not possible as a frontline treatment or to test large numbers of koalas,” he said.

“Our new project aims to fill this gap by seeking to combine the markers for chlamydia disease progression into a single panel to test for these risk factors, which could help veterinarians decide whether to treat with antibiotics or not.”

/University Public Release. View in full here.