Project Summary

We agree to participate in a collaborative approach with FRDC research partner CSIRO Agriculture and Food St Lucia and will instate an overarching Steering Committee comprised of members from both participating organisations:
•     Dr Roger Chong, CSIRO
•     Dr Terry Miller, Queensland Museum
•     A/Prof Nathan Bott,Royal Melbourne Institute of Technology (RMIT) University
•     Dr Cecilia Power, RMIT University

The Steering Committee will aim to meet online every month and as needed to ensure successful delivery of the project.

Our research strategy proposes two approaches as illustrated in Figure 1 and Figure 2.

Strategy A : Parasite Risk Mapping (This is a collaborative effort between CSIRO, Queensland Museum, and RMIT University).

A parasite risk map  (pathogen environmental monitoring, disease mapping)

• This is a surveillance program using the most sensitive laboratory-based tests. The concept is not new and is the basis for improved risk assessment to achieve health goals (Jarup, 2004).
• It will produce a map of risk for the parasite that is correlated spatially (geographically) and temporally (seasons).
• Commercial Fishers (CF) can use this risk map to support decisions as to where and when to target fish species that are susceptible to the parasites.
• It is like a tide chart, which has predictive value and informs on risk.
• CF will save operating costs by not going to fish where and when the risk map is predicting an unacceptable level of parasite infestation.
• It is not a reactive method to discard affected fish but uses these fish as a resource to develop part B of the research strategy.
• It requires significant commitment from CF in the project to complete the surveillance program (1,2,3 years).
• The greater the collection of parasite prevalence and severity data, the more robust will be the predictive value of the Kudoa-Unicapsulae Risk Map (KURM).
• Voucher specimens for definitive characterisation of the species of Kudoa and Unicapsulae myxozoans will be collected for Queensland Museum work.

Organisation of the project consortium work plan

1. The PCR test(s) and kit development will be performed by RMIT University. The costs of this work is outside the scope of this revised CSIRO project proposal. From the previous version of the submitted proposal, it is estimated to be of the order of $190,000 over 3 years.

2. Somewhere in the ball park of 900 fish samples will be tested by RMIT University. This could mean between 1,500-2,000 individual PCR assays to achieve the required sensitivity of detecting the parasite, particularly if they occur at low prevalence during the surveillance period. These results are foundational to the construction of the parasite risk map(s).

3. CSIRO team will design and operate the surveillance (fishing) program to collect target fish species over 3 years.

4. CSIRO team will design and organise collection of the initial gross and histopathology samples, the PCR samples. 2 fillets will be retained from each fish and stored long-term in freezer storage space. These can be archival material to test the degree of liquefaction if required as a quality control step to verify how much parasite infestation (quantitative PCR copies of the parasite) is needed to trigger the ‘meltdown’ effect, i.e., the tipping point parasite load. This will provide quantitative predictive value to the parasite risk map(s).

5. CSIRO team will perform the initial screening test using gross and histopathology. The results will be a basis for validation of the PCR results. Quantification of the parasite density in fish is required for the parasite risk map.

6. CSIRO team will send all collected and preserved PCR samples to RMIT University for testing with their PCR and kit assays. CSIRO will provide to RMIT University the results of the gross and histopathology work, so that the PCR/test kits can be validated and optimised for field use. Voucher specimens for definitive characterisation of the species of Kudoa and Unicapsulae myxozoans will be collected for Queensland Museum work.

7. All the results of the PCR and kit assays will return to CSIRO team for data entry to construct the parasite risk map(s).

Figure 1. Strategy A : Schematic of parasite risk map research strategy for Kudoa-Unicapsula-soft-flesh syndrome (see attached file).