Murdoch Uni researchers detect new bacteria species in Australian ticks similar to type responsible for relapsing fever


Stock image.
Stock image.

MURDOCH University researchers have detected a new species of bacteria in Australian ticks similar to that known for causing tick-borne relapsing fever overseas.

The discovery was published by Murdoch researcher Charlotte Oskam in the parasitology journal Parasites and Vectors.

To date, little has been documented about microorganisms harboured within Australian native ticks or their potential to transmit disease.

The study concentrated on ticks removed from echidnas on Australia’s east coast, with researchers discovering the presence of a Borrelia bacteria species separate to a group of bacteria which causes Lyme disease in the northern hemisphere.

The new species is genetically related to the Borrelia group causing tick-borne Relapsing Fever (RF) overseas but its discovery has the potential to form its own major bacteria group.

“Just like our native wildlife, the new bacterium discovered is unique to Australia and unique to ticks that bite echidnas,” Dr Oskam said.

The new bacterium was found in ticks removed from echidnas in Queensland and New South Wales, but not in Victoria, with Dr Oskam admitting further research was needed to uncover the disease potential and consequences of the bacteria.

“We don’t know at this stage whether this new bacterium can cause disease or if this bacterium can be transmitted by ticks. It’s too early to say,” she said.

“Also of note is this type of tick doesn’t bite humans – it prefers echidnas – so we need more information about this particular Borrelia. For example, it’s present in echidna ticks but can we find it in the echidnas themselves?”

Ticks transmit the most diverse range of animal-to-human pathogens of any arthropod – a major concern to the health and wellbeing of humans, wildlife, livestock and companion animals.

For many pathogens transmitted by overseas ticks to wildlife, the animal is rarely affected.

“But when people go into these environments and get bitten, they can get sick,” Dr Oskam said.

“By looking at the wildlife, we can start piece together a view of what could cause illness in humans.”