15 August 2011

Australian scientists believe they may be a step closer to finding a cattle tick vaccine that could save the national cattle and dairy industries approximately $175 million per annum and reduce the need for pesticides.

Using a novel science that has not been carried out anywhere else in the world, researchers have pinpointed tick vaccine antigens that will enable cattle to resist tick infestations. The vaccine antigens produce a bovine immune response that interferes with tick attachment and feeding (reducing tick numbers by up to ~60 per cent) and also interferes with the ability of surviving ticks to lay eggs.

The research, which is being led by the Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland and the CRC for Beef Genetic Technologies, recently recorded 50 to 87 per cent protection from ticks in cattle trials using pre-optimised immunisation conditions. This outcome has caught the attention of commercial companies and highly regarded scientific journals alike.

According to QAAFI scientist, Dr Ala Lew-Tabor, tick management and losses due to the parasite costs the national cattle and dairy industries approximately $175 million per annum.

“In 2008, Meat and Livestock Australia pinpointed tick infestation as the ‘number one’ cattle health problem in the country,” Dr Lew-Tabor said.

“In recent years traditional means of controlling ticks (using anti-tick pesticides called acaricides) is slowly declining due to ticks developing resistance to the available classes of acaricides.

“During our five-year research program, we have developed new tick research tools, generated 10 times more tick genomic data and established a specific bioinformatics capacity through Murdoch University’s Centre for Comparative Genomics.”

Dr Heather Burrow, CEO of the Beef Genetic Technologies CRC, said that reduced productivity in the beef and dairy industries due to tick infestation is currently one of the most costly and difficult management issues and has high impacts on cattle welfare.

“This work is novel science that has not been carried out anywhere else in the world. Together with our USA and Brazilian partners, Australia stands to lead the way in safe and effective tick management,” Dr Burrow said.

As part of the study, Dr Ala Lew-Tabor and her team fed adult ticks with antibodies to these corresponding genes with the overarching aim of identifying a safe and effective alternative means of reducing cattle and dairy disease caused by Australia’s most common species of tick.

Dr Lew-Tabor said that while the project team had made excellent progress through the discovery and testing of these potential tick vaccine candidates, a commercial product is still a few years away.

”Once potential vaccine candidates are licensed to a pharmaceutical company to develop into a commercial vaccine, it takes approximately five to eight years to complete registration requirements for use in Australia and overseas.”

Partners in the tick research project includes the Queensland Government’s Department of Employment, Economic Development and Innovation (DEEDI), Murdoch University’s Centre for Comparative Genomics, Perth, the US Department of Agriculture – Agricultural Research Services, and The Brazilian Agricultural Research Corporation (EMBRAPA).

The group of scientists have used and refined tick gene silencing techniques to help them screen for vaccine antigens that will suspend the tick life cycle.

Dr Lew-Tabor’s team’s research was recently published in an article, ‘Gene expression evidence for off-target effects caused by RNA interference-mediated gene silencing of Ubiquitin-63E in the cattle tick Rhipicephalus microplus’, in the International Journal for Parasitology (as Issue 9’s ‘highlighted article’) and this will guide other tick researchers in the development of gene silencing treatments. Dr Lew-Tabor has also been appointed a Specialist Editor for the Journal.

Media: Julie Lloyd, QAAFI Communications Manager, 0415 799 890.

QAAFI background
Launched on 21 October, 2010, the Queensland Alliance for Agriculture and Food Innovation (QAAFI) is an Institute of The University of Queensland (UQ) and was formed through an alliance between UQ and the Queensland Government’s Department of Employment, Economic Development and Innovation (DEEDI). QAAFI draws together 100 research teams specialising in plant, animal and food sciences from twelve UQ and DEEDI sites across Queensland. The QAAFI Vision is to be a world leader in tropical and subtropical agricultural and food research and development. QAAFI will ensure that cutting-edge science and science education is applied to support sustainable tropical and subtropical agriculture and food production.

Beef CRC background
The Cooperative Research Centre (CRC) for Beef Genetic Technologies commenced its third term of operations in July 2005. Beef CRC comprises research and industry partners from Australia, New Zealand, USA, Canada, Brazil, Korea, Ireland, France and South Africa, all of whom are collaborating with the direct aim of value-adding the beef industries of their own countries. Beef CRC aims to increase competitiveness of Australia’s beef industry by;
• improving the capacity to deliver high quality beef to Australia's domestic and international markets, without compromising animal welfare or the environment; and
• enhancing throughput and efficiency of resource use and reducing production costs, methane emissions and avoiding chemical and antibiotic residues through precise application of knowledge about the genes controlling these attributes in cattle, their rumen microorganisms and in parasites affecting herd productivity