WP5-T1 Develop and evaluate methods for pathogen inactivation and decontamination of systems and animals

Participants :

  • 1 - IFREMER
  • 11 - ATLANTIUM

Possibility of pathogen survival in sea water and on materials and equipments used in hatchery, nursery and transport will be estimated from data obtained in WP3 Task 2 and will allow selecting pathogens to be tested in this task.

Sub Task 5.1 - Inactivation of pathogens in sea water and on materials and equipments

Physical treatments including ozone, filtration, UV and the Hydro Optic Disinfection system as well as chemical treatments will be tested for pathogen inactivation in sea water and on materials and equipments.

Pathogen inactivation in the sea water will be based mainly on the Hydro Optic disinfection system using the methodology and experience gathered in the aquaculture industries for defining the UV germicidal dose necessary to inactivate the identified microbes using a laboratory static UV setup -Collimated Beam Apparatus (CBA). The outcome of this activity will be a dose response curve for each pathogen defined in the previous activities. The dose response curve is crucial to complete the HOD system to ensure the inactivation levels.

Inactivation efficiency will be evaluated for the pathogens that were defined in WP3 and by using techniques and parameters developed in WP4 Task 1. Impact of each treatment on the environment (toxicity) will be taken into account when selecting the most efficient treatments for the following sub task. In addition, the capability of the HOD system for delivering a precise dose enables adding an additional pathogen blocking layer. The precise delivered dose of the HOD enables the option of performing selective inactivation.

Sub Task 5.2 - Inactivation of pathogens in hatchery-nursery conditions

Hatchery-nursery conditions are more complex than merely sea water therefore efficiency of selected treatments will be tested in the environmental conditions presently used in a hatchery/nursery, such as influenced by the presence of algae and the use of specific temperatures. Efficiency of treatments, including HOD treatment for enhancing controlled growth conditions, will be evaluated and will be tested by modulating environmental
conditions.

The HOD system will be completed according to the activities of WP2 and WP6 Task 1 and implemented for treating the intake water, circulation and effluent water for environment protection. In addition to these barriers, a live feed disinfection barrier will be implemented for assuring the absence of cross contamination entering with the live feed. During this process the toxicity potential due to algal disinfection will be evaluated. In addition, broodstock decontamination will be investigated by testing antibiotic, probiotic and antiviral treatments on breeders before spawning. Efficiency of treatments will be determined by testing a short term effect that will be evaluated by the presence and amount of pathogens in breeders and in larvae produced and for long term effects by evaluating the stability of the treated animals in the grow out conditions. A flow system based on the HOD that was modified and sized according to the information gathered and defined in the previous WPs will be used.