Aquafin CRC - Atlantic Salmon Aquaculture Subprogram: host-pathogen interactions in Amoebic Gill Disease

Funded Activity Summary

This project will develop methods and provide information for vaccine and novel treatment development. For example, techniques for the isolation and maintenance of N. pemaquidensis are based on monoxenic cultures. This culture is highly problematic because preparations of protozoa are contaminated with bacteria. Studies to determine cell function, protein and DNA composition have been seriously compromised by the bacteria. Culture relies on the use of agar. Cell propagation and harvesting by this system is time consuming and inefficient. Development of practical systems for cell factory production of N. pemaquidensis is required. This is important for studies of cell wall composition and cell function, which require considerable biomass. There is no model of infection using protozoa derived from monoxenic or xenic cultures. This represents a major limitation, particularly when it is necessary to use controlled doses of a single strain. Current methods rely on the use of N. pemaquidensis harvested from infected fish. While this strategy meets an immediate need, long-term it cannot be justified. Development of a method to grow in vitro virulent protozoa capable of infecting fish is an essential objective. The current library of N. pemaquidensis isolates obtained from fish with AGD is small and in continuous culture for almost 10 years. There is an urgent need to re-isolate N. pemaquidensis and expand the library to ensure an adequate range of phenotypes and genotypes. Preservation of N. pemaquidensis is an essential requirement of the AGD programme as it will maintain strain integrity, a vital objective for vaccine development. The complexity of growing N. pemaquidensis has proved a major limitation to studies on AGD. A centre of expertise in the culture of N. pemaquidensis should result in guaranteed supply of organism. A reference laboratory will ensure standardisation of cultures and uniformity of research outcomes.

Objectives:
1. To provide a knowledge base for development of novel treatments and vaccines
2. To identify factors leading to binding of the parasite to fish gills
3. To identify gill conditions which increase the susceptibility of the fish to AGD
4. To develop techniques for in vitro work on Amoebic Gill Disease
5. To expand the library of N. pemaquidensis strains
6. To implement a long term preservation for N. pemaquidensis based on freezing technology
7. To develop improved culture systems based on monoxenic and axenic techniques
8. To develop cell factory capability to produce high density cell suspensions of N. pemaquidensis
9. To develop cell purification techniques to produce pure cell suspension of N. pemaquidensis derived from cell culture and gill associated disease.
10. To implement cell characterisation techniques for strain differentiation
11. To investigate culture strategies to develop infective strains of in vitro grown N. pemaquidensis

Funded Activity Details

Start Date: 31-01-2002

End Date: 24-05-2005

Funding Scheme: Funding Scheme not available

Funding Amount: $860,814.00

Funder: Fisheries Research and Development Corporation

Research Topics

ANZSRC Field of Research (FoR)

There are no FoR codes available for this funding activity

ANZSRC Socio-Economic Objective (SEO)

There are no SEO codes available for this funding activity

Other Keywords

Animal Health | Animal Welfare | Aquaculture | Biosecurity | Disease

Related Links