Updated: Feb 27, 2019
Traditional Pacific Oyster Mortality Syndrome (POMS) testing currently relies on intensive sampling of oysters with expensive qPCR lab testing; But is this feasible for the Australian Oyster industry?
During the February 2016 POMS outbreak in Tasmania, both Tasmania and South Australia required substantial qPCR testing to define POMS infected areas and prove that response measures had prevented entry of the disease.
This exercise has motivated the Australian Oyster industry and State government to find a more cost-effective solution, especially for early detection in currently unaffected regions.
Flinders University in collaboration with PIRSA-SARDI are investigating a novel flow cytometry method for the detection of POMS through the Future Oysters CRC-P. Leading the way has been Jim Mitchell and James Paterson from Flinders University.
James describes the flow cytometer as “a rapid, low cost and quantitative test for the presence of POMS. It is able to give results from sample collection in under one hour, which costs less than $2 per sampled analysed. The device is highly portable and is set up for easy operation.”
This is significant in terms of time and cost when compared with traditional PCR lab testing. PCR tests are collected and sent away to a certified laboratory for analysis. A result may take one to two weeks to obtain considering sample shipping and laboratory turn around times. Costs of traditional PCR tests are approximately 10-100 times more expensive than this new flow cytometry method. Another benefit to this new method is the ability to run samples yourself without the need for extensive training.
The Flow Cytometer has five easy steps from sample collection to end result:
For more information on how the machine works, please watch this video: https://www.youtube.com/watch?v=7FBSyHSNTNo
James has been testing the flow cytometer with a POMS primer probe and has been refining the methods to get the method robust for POMS analysis. The initial trials have been successful. The virus signal was clearly visible in initial samples tested (Figure 1).
Figure 1. Output of two separate samples run through the Muse flow cytometer. (A) Seawater sample without the presence of OsHV-1. (B) Sample containing OsHV-1 virus.
Further work is being done to optimise the Flow Cytometer test and reduce background noise. POMS PCR tests are also being implemented and are being used as a validation tool.
“This machine is still in its beta phase. We refining its method so that results are consistently accurate in the lab and field before we roll it out. We also want to look at ways of reducing the one-hour processing time so that the results are almost instant. Our aim is to provide industry with cost effective surveillance mechanisms to demonstrate freedom in uninfected areas and to monitor viral load and changes in disease at infected sites.”
For more information on this project, please visit: https://www.oystersaustralia.org/project-2016-806
The author acknowledges that the CRC Program supports industry-led collaboration between industry, researchers and the community. The Future Oysters CRC-P, which focuses on the production of ‘Better’, ‘Healthy’ and ‘More’ oysters, is led by Australian Seafood Industry Pty Ltd in partnership with Oyster Australia Ltd, Select Oyster Company Pty Ltd, Fisheries Research and Development Corporation, Department of Primary Industries and Regions (South Australian Research & Development Institute), University of Tasmania, The Flinders University of South Australia, The University of Newcastle, The University of Adelaide, Commonwealth Scientific and Industrial Research Organisation, University of Technology Sydney, University of Sunshine Coast, Macquarie University, Department of Skills and Regional Development (NSW), and The Yield Technology Solutions Pty Ltd.