A silicone membrane and cattle blood replace live animals in tick research

Published in The Veterinary Journal. University of Melbourne.

Tick research has long required live animals. To study how ticks feed, transmit pathogens, or respond to vaccines and pesticides, researchers have had to attach the parasites to cattle, rabbits, or other hosts and wait. The process is expensive, labor-intensive, ethically fraught, and introduces variability from host immune responses and grooming behavior that can confound results.

A team at the University of Melbourne has now built something that changes that equation: the first laboratory-based artificial feeding system for bush ticks. Published in The Veterinary Journal, the work demonstrates that the Asian longhorned tick (Haemaphysalis longicornis) can feed and complete its full reproductive cycle on a platform made from a silicone membrane and cattle blood, with no animal host involved.

The engineering challenge of short mouthparts

Artificial feeding systems have existed for some tick species, but the Asian longhorned tick presented specific anatomical obstacles. Its mouthparts are short, and its mobility is limited compared with tick species for which artificial feeding had already been demonstrated. Previous attempts to feed H. longicornis on membranes had failed to achieve reliable attachment and engorgement.

The team, led by Dr. Abdul Ghafar and Professor Abdul Jabbar at the Melbourne Veterinary School, working with Professor Ard Nijhof from Freie Universitat Berlin, overcame these constraints by optimizing membrane thickness and feeding conditions. The silicone membrane replicates the key mechanical properties of animal skin, and the blood supply uses cattle blood from which the clotting protein fibrin has been removed to prevent coagulation in the feeding apparatus.

What the platform enables

Beyond replacing animal hosts, the artificial system opens experimental possibilities that live-animal studies cannot match. It allows controlled studies of tick physiology, microbiome dynamics, pathogen acquisition and transmission, and high-throughput screening of pesticides and anti-tick vaccines under standardized conditions. Because the system eliminates host variability, experiments become more reproducible.

"This is not only labour-intensive, costly and ethically challenging, but also risks introducing substantial variability due to host immune responses, grooming behaviour and individual differences in tick attachment and feeding success," Nijhof said of the traditional approach.

Why this tick species matters

The Asian longhorned tick is widespread in Australia, where it is the primary vector for Theileria orientalis, a parasite that causes significant production losses in cattle. The tick has also spread to the eastern United States, where it was first detected in 2017 and has since been found in more than a dozen states.

Emerging evidence has linked bites from H. longicornis to alpha-gal syndrome in humans, an allergic reaction to a carbohydrate in tick saliva that causes red-meat allergy. The condition, which can develop suddenly in adults with no prior food allergies, has drawn increasing public attention as its geographic range expands.

Limitations and next steps

The study demonstrates proof of concept for one tick species under controlled laboratory conditions. Whether the platform can be adapted for other medically and veterinary important tick species with different feeding behaviors and mouthpart anatomies remains to be tested. The system also does not replicate the immune environment of a living host, which means studies of host-tick immune interactions will still require animal models for the foreseeable future.

Long-term reliability of the feeding platform across multiple tick generations and its suitability for pathogen transmission studies, where the tick must acquire a microorganism from one blood meal and transmit it during another, are questions the researchers plan to address in follow-up work.

"As climate change, land-use change and global trade continue to reshape the distribution of ticks and tick-borne diseases in Australia, this host-free feeding system can support integrated research on disease-carrying animals like ticks of importance to animal and human health," Ghafar said.