Needle-free vaccination against tenacibaculosis in Atlantic salmon
Ulcer development caused by bacterial infections in the sea is a large problem in the Norwegian salmon farming industry. The “winter ulcer disease” associated with the bacteria Moritella viscosa and tenacibaculosis associated with Tenacibaculum spp., are the main cause of concern (Fiskehelserapporten 2020). In recent years, Tenacibaculum finnmarkense has been an increasing problem in Northern Norway. Outbreaks of tenacibaculousis result in major losses, often associated with smolt transfer to seawater. Despite the significance of ulcerative outbreaks caused by T. finnmarkense in farmed Atlantic salmon, there is a lack of information concerning tenacibaculosis. Effective vaccination would represent an easy and available approach limiting the disease, but at present there is no effective vaccine against tenacibaculosis in salmonids.
Here, we aim to investigate stimulation of mucosal immunity against the Tenacibaculum proteins TenT and PepM9 by bath and by nasal immunization.The specific antibody response in the exposed groups developed in smolts and at two different temperatures after seawater transfer will be determined. In this study, we will investigate immune responses after exposure to the proteins; with bath model, nasal, or cutaneous administration of the antigens to identify the best approach for immunization. Such knowledge has the potential to change the direction on how mucosal barriers can be strengthened by immunization. Administering the antigen by either bath or nasal vaccination eliminates the need for injecting the fish as well as directly targeting the mucosal immune compartments in the skin.
We expect mild degree of distress. Under nasal application of aqueous solution of proteins, and subcutaneous injection the fish will be fully anesthetized. Activation of immune responses is anticipation with mild transient effect on the fish. Pit-tagging of the fish will also be performed on fully anesthetized fish.
The experiment will apply 240 Atlantic salmon, determined on the basis of the minimum number of fish required for three samplings, 1) control at exposure, 2) prior to seawater transfer (effect of immunization) and 3) final sampling two weeks after seawater transfer (effect of immunization and seawater transfer). Fish in flow-through fresh water (size > 30 grams) will be pit-tagged to allow groups to be mixed, reducing the number of tanks and fish in the experiment. After recovery, fish will be stimulated to develop immune responses, just prior to the 24 h light photoperiod. After six weeks fish will be at the end of smoltification. Fish will be sampled and the groups split when transferred to flow-through seawater. The trial will continue in seawater for two more weeks with temperatures of either 4C or 8C. The total length of the trial is 9 weeks.
Here, we aim to investigate stimulation of mucosal immunity against the Tenacibaculum proteins TenT and PepM9 by bath and by nasal immunization.The specific antibody response in the exposed groups developed in smolts and at two different temperatures after seawater transfer will be determined. In this study, we will investigate immune responses after exposure to the proteins; with bath model, nasal, or cutaneous administration of the antigens to identify the best approach for immunization. Such knowledge has the potential to change the direction on how mucosal barriers can be strengthened by immunization. Administering the antigen by either bath or nasal vaccination eliminates the need for injecting the fish as well as directly targeting the mucosal immune compartments in the skin.
We expect mild degree of distress. Under nasal application of aqueous solution of proteins, and subcutaneous injection the fish will be fully anesthetized. Activation of immune responses is anticipation with mild transient effect on the fish. Pit-tagging of the fish will also be performed on fully anesthetized fish.
The experiment will apply 240 Atlantic salmon, determined on the basis of the minimum number of fish required for three samplings, 1) control at exposure, 2) prior to seawater transfer (effect of immunization) and 3) final sampling two weeks after seawater transfer (effect of immunization and seawater transfer). Fish in flow-through fresh water (size > 30 grams) will be pit-tagged to allow groups to be mixed, reducing the number of tanks and fish in the experiment. After recovery, fish will be stimulated to develop immune responses, just prior to the 24 h light photoperiod. After six weeks fish will be at the end of smoltification. Fish will be sampled and the groups split when transferred to flow-through seawater. The trial will continue in seawater for two more weeks with temperatures of either 4C or 8C. The total length of the trial is 9 weeks.