Barramundi Disease Breakthrough

Posted by Josette Dunn on 12th March 2010

A new project led by The University of Sydney seeks to improve existing methods of detecting a fish disease which is damaging the barramundi industry in Australia.Thanks to a major breakthrough in DNA-detection technology in 2009, a new test is available for the nervous necrosis virus-a serious disease affecting over 35 species of fish worldwide. In Australia, this disease has mainly affected the production of barramundi, with losses of up to 100 per cent occurring in some hatcheries.

Professor Richard Whittington, Principal Investigator and Chair of Farm Animal Health in the Faculty of Veterinary Science at the University of Sydney, says the disease has prevented the expansion of the industry and hampered productivity. It has also made restocking wild fisheries much more difficult, due to fears the disease may spread.

Prior to the development of the new DNA detection technology, laboratories used the gel-based polymerase chain reaction (PCR) method as the validated test to find signs of the nervous necrosis virus.

“The old test was not very sensitive, and in many cases, infection was present yet still turned up negative,” explains Professor Whittington.

“For that reason, the result of the test did not really predict the likelihood of an outbreak occurring.”

The new PCR method will allow researchers to concentrate the genome from the virus so that it can be detected in a very sensitive laboratory procedure.

The new study will also improve detection by developing and applying serological tests – identifying antibodies in blood serum – to complement the PCR method. This will provide the information as to whether the antibody status should be used as an indicator of infection in a fish population.

Launched after the largest consultative meeting in Australia in 2007, the project is a major national collaborative research program to control the disease. The meeting included State Departments of Primary Industries, CSIRO, representatives from the Australian Barramundi Farmers Association as well as the Department of Agriculture, Fisheries and Forestry.