Antibiotic resistant gene found in SEQ horses | UniSC | University of the Sunshine Coast, Queensland, Australia

Research into a common environmental germ that can cause severe infections in people and animals has raised concern that horses are starting to develop antibiotic resistance towards it.

The University of the Sunshine Coast study examined the prevalence of the bug P. aeruginosa in Australian wild birds, native wildlife, livestock and domestic animals.

Declared a priority pathogen by the World Health Organisation, the bacteria poses a threat to medical, veterinary and agriculture practices globally. 

Found naturally in water and soil, it can cause many types of infections and is particularly risky for people with lung conditions or poor immune systems.

“Understanding its prevalence in wild and domestic animals is vital for evaluating potential reservoirs of infection,” said lead author Kellie Strickland.

The UniSC team screened almost 1,700 DNA samples obtained between 2010 and 2023 from healthy and diseased birds, pets, horses, cattle, kangaroos and koalas in South East Queensland.

“We thankfully found a low infection rate across nearly all animals tested, however domestic horses stood out with the highest rate of seven percent,” she said.

“While this was notable because P. aeruginosa infections can cause fertility and pregnancy problems in mares, the results are comparable with international research.

“Of significant concern to our team was the discovery of a genetic mutation in the bug, detected in two of the horse samples. The mutation is known to cause resistance toward an antibiotic often used to treat P. aeruginosa infection in both humans and horses.”

The results have been published in a paper in Scientific Reports, with co-authors including Kellie Strickland’s PhD supervisor, molecular microbiologist and UniSC Senior Research Fellow Dr Derek Sarovich.

Associate Professor Sarovich said antimicrobial resistance was one of the world’s most pressing health issues.

“This is believed to be the first reported instance of the clinically important mutation in horses, and further research is needed across a broader geographic region,” he said.

“The results emphasise how humans, wildlife, animals and the environment are inextricably linked, and pathogens like this need to be tackled holistically and collaboratively on a global scale, as outlined by the World Health Organisation.”