Vaccination for emergency and long-term control of nodavirus in Australian marine aquaculture
SCRC: PhD : Increasing Oyster Spat Production Through Management of Microbiological Contamination
Vibrio species are a notorious pest in all aquaculture systems, producing significant losses in productivity. However, the problem still persists today because the causative agents and associated virulence factors have not been adequately identified and, because little is known about environmental conditions that cause the pathogen(s) to proliferate. Supply of oyster spat is currently failing to meet demand consistently in Australia, with Australian hatcheries only producing seed for the local market of approximately 250 million a year compared to a world market in excess of 10 billion oyster seed. Solving this problem will allow Australian oyster hatcheries to design and implement effective risk management systems, thus increasing supply to expand national and international markets. In addition, the aquaculture industry needs greater human capability and capacity to manage disease in aquaculture operations.
Relevance to industry priorities and Seafood CRC milestones
The associated Program and theme is within Production Innovation – Program Manager Dr Graham Mair - Outcome: Increased profitability and industry value through production innovation.
Specific output and associated milestones include:
1.3 Output: Removal or reduction of key production constraints in selected aquaculture systems
1.3.3 Milestone: Strategic disease management approaches and technologies developed for at least two aquaculture species
1.3.5 Milestone: Production efficiency gains from genetic, health management and nutritional interventions quantified to inform long-term strategies and estimate commercial benefits
Diagnostic detection of aquatic pathogens using real-time next generation sequencing
Current diagnostic programs generally rely on highly -specific assays for pathogen detection. While these techniques are invaluable, they are one dimensional and do not provide detailed information critical to a disease investigation. These gaps include the inability to detect unknown pathogens and potential variants of know pathogens and provide no additional genomic or transcriptomic data. Moreover, samples must be shipped to trained personnel in a laboratory, further delaying the time to diagnosis. The MinION, on the other hand, can theoretically detect any pathogen and can potentially be deployed to the field. Moreover, the MinION can rapidly generate full-length genomes, allowing for epidemiological tracking of viral or bacterial strains in near real-time. Such rapid data, which cannot be obtained as quickly using existing methods, are vital if the intention is to intervene in an outbreak and reduce impacts on the productivity and profitability of aquaculture facilities. For example, a rapid, early diagnosis may allow mitigating actions to be taken on-farm, such as the diversion of intake water, movement restrictions of stock and the isolation of infected ponds.
These qualities make the MinION an attractive complimentary platform to fill several gaps in the data obtained during disease outbreak investigations, or routine diagnostics, and potentially for use in the field. However, results from the misuse or lack of understanding of the technology could also have adverse regulatory implications for aquaculture industries. For example, without appropriate guidelines, an inexperienced diagnostician may misinterpret a distant DNA match in a pathogen database as a significant result, this may create unwanted attention to industry and potential stock destruction or changes to disease status that are unjustified. Thus, it is critical that the MinION is evaluated at the Australian Animal Health Laboratory, and guidelines and procedures are developed for accurate diagnostic evaluations. The activities detailed in this application will establish the feasibility of using the MinION for diagnostic applications, and ensure that the data is reliably generated and interpreted appropriately.