Compositions and methods for immunizing atlantic salmon

Abstract

The present disclosure provides compositions and vaccines directed to immunization of animals. Methods of using the compositions and vaccines protection of animals, in particular aquaculture animals, against one or more species of bacteria are also provided.

Description

[0001] COMPOSITIONS AND METHODS FOR IMMUNIZING ATLANTIC SALMON

[0002] TECHNICAL FIELD

[0003] The disclosure relates to compositions and vaccines directed to immunization of animals. In one aspect, the present disclosure provides compositions and methods directed to protection of fish against one or more species of bacteria.

[0004] BACKGROUND AND SUMMARY OF THE INVENTION

[0005] Aquaculture is a significant industry for providing sustenance to populations around the world. In particular, fish such as salmonoids are an important food source in many North American and European countries. However, salmonoids are increasingly susceptible to bacterial pathogens.

[0006] Vaccines to reduce the incidence of bacterial infection are currently available. However, current vaccines could be improved if additional immunologically effective antigens are available. Furthermore, vaccines containing bacterial antigens from alternative countries of origin are highly desirable. Thus, there exists a need for new vaccines directed to immunization of animals such as fish against bacterial pathogens.

[0007] Moritella (M.) viscosa is the aetiological agent of winter ulcer disease affecting farmed salmonids at sea, typically at water temperatures below 10°C. Once infected, characteristic ulcerative lesions of the skin extending into the underlying musculature of fish are often observed. Although mortality following infection is often reported to be less than 10%, the most significant economic impact to the industry is due to the downgrading of fish at harvest from the effects of ulceration on flesh quality (Lovoll, M. et al., 2009, Fish & Shellfish Immunology, vol. 26, p. 877 - 884). Since its discovery, M. viscosa has been divided into two major genotypic and phenotypic clades, “typical” and “atypical.” The clades represent different geographical locations where “typical” strains are found in Norway, Scotland, and the Faroe Islands. In contrast, “atypical” strains are found in Iceland, Canada, and farmed trout in Norway (Karlsen, C. et al., 2017, Aquaculture, vol. 473, p. 538 - 544). Although commercial vaccines with an indication for M. viscosa are widely employed in aquaculture, there remains a question of cross-protection against varying strains and clades of the disease. Thus, vaccines containing M. viscosa antigens should be tested against local “atypical” M. viscosa in Canada. Therefore, the current study aimed to test the efficacy of an experimental vaccine against M. viscosa isolated from clinical cases of the disease in Atlantic salmon smolts cultivated in Canada. To date in North America there are no licensed multivalent oil vaccines available with label indications against M. viscosa, the causative agent of Winter Ulcer disease in Salmonids. Although some producers have used EU licensed vaccines with indications for preventing M. viscosa, there is no evidence that these vaccines provide protection against Canadian isolates of the disease within Canadian stocks of Atlantic salmon.

[0008] Accordingly, the present disclosure provides immunological compositions and vaccines directed to immunization of animals against bacterial pathogens. The exemplary embodiments of the present disclosure include several desirable features. For instance, the immunological compositions and vaccines described herein utilize distinctive antigens to help combat the ever-evolving bacterial infections in aquaculture. Moreover, the immunological compositions and vaccines can provide cross-protection between bacteria, including across different geographical regions.

[0009] Various aspects of the disclosure are described more fully below. However, different aspects of the disclosure may be implemented in many ways and should not be construed as limited to the aspects set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense.

[0010] BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIGURE 1 shows the cumulative percent mortality over time following challenge with region-specific isolates.

[0012] FIGURE 2 shows the percent mortality and relative percent of survival following various treatments and challenges.

[0013] FIGURE 3 shows a whole genome sequence based dendrogram of Canadian isolates 532 and 371 with other NCBI entries. Each isolate displays information including country, year, and species of isolation. The reference genome isolate (LFI 5006) is noted in the fiture. MVIS1 and 0609139 represent the same isolate with partial and complete MVIS1 sequencing.

[0014] DETAILED DESCRIPTION

[0015] Various embodiments are described herein as follows. In an illustrative aspect, an immunogenic composition is provided. The immunogenic composition comprises an immunogenically effective amount of an antigen of Moritella viscosa.

[0016] In an embodiment, the antigen of Moritella viscosa is of Canadian origin. In an embodiment, the antigen of Moritella viscosa is not of Norwegian origin.

[0017] In an embodiment, the immunogenic composition further comprises an immunogenically effective amount of an antigen of Aeromonas salmonicida. In an embodiment, the antigen of Aeromonas salmonicida is of U.S. origin. In an embodiment, the antigen of Aeromonas salmonicida is not of Norwegian origin.

[0018] In an embodiment, the immunogenic composition further comprises an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I. In an embodiment, the antigen of Vibrio anguillarum serotype I is of U.S. origin. In an embodiment, the antigen of Vibrio anguillarum serotype I is not of Norwegian origin.

[0019] In an embodiment, the immunogenic composition further comprises an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II. In an embodiment, the antigen of Vibrio anguillarum serotype II is of Canadian origin. In an embodiment, the antigen of Vibrio anguillarum serotype II is not of Norwegian origin.

[0020] In an embodiment, the immunogenic composition further comprises an immunogenically effective amount of an antigen of Vibrio ordalii. In an embodiment, the antigen of Vibrio ordalii is of U.S. origin. In an embodiment, the antigen of Vibrio ordalii is not of Norwegian origin.

[0021] In an embodiment, the immunogenic composition further comprises an immunogenically effective amount of an antigen of Vibrio salmonicida serotype I. In an embodiment, the antigen of Vibrio salmonicida serotype I is of Norwegian origin.

[0022] In an embodiment, the immunogenic composition further comprises an immunogenically effective amount of an antigen of infectious salmon anaemia virus (ISAV). In an embodiment, the antigen of ISAV is of Canadian origin. In an embodiment, the antigen of ISAV is not of Norwegian origin.

[0023] In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio salmonicida serotype II. In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 01. In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 02a. In an embodiment, the immunogenic composition does not comprise an antigen of Infectious pancreatic necrosis virus.

[0024] In an embodiment, the immunogenic composition further comprises an adjuvant. In an embodiment, the adjuvant is an oil-based adjuvant. In an embodiment, the immunogenic composition further comprises a veterinary acceptable carrier.

[0025] In an illustrative aspect, another immunogenic composition is provided. The immunogenic composition comprises an immunogenically effective amount of an antigen of Moritella viscosa. an immunogenically effective amount of an antigen of Aeromonas scilmonicida, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II, an immunogenically effective amount of an antigen of Vibrio ordalii, and an immunogenically effective amount of an antigen of Vibrio salmonicida.

[0026] In an embodiment, the immunogenic composition further comprises an antigen of one or more microorganisms selected from the group consisting of Aeromonas salmonicida, Vibrio anguillarum, Vibrio ordalii, Vibrio salmonicida, and infectious salmon anaemia virus (ISAV).

[0027] In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio salmonicida serotype II. In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 01. In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 02a. In an embodiment, the immunogenic composition does not comprise an antigen of Infectious pancreatic necrosis virus.

[0028] In an embodiment, the immunogenic composition further comprises an adjuvant. In an embodiment, the adjuvant is an oil-based adjuvant. In an embodiment, the immunogenic composition further comprises a veterinary acceptable carrier.

[0029] In an illustrative aspect, yet another immunogenic composition is provided. The immunogenic composition comprises an immunogenically effective amount of an antigen of Moritella viscosa, an immunogenically effective amount of an antigen of Aeromonas salmonicida, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II, an immunogenically effective amount of an antigen of Vibrio ordalii, an immunogenically effective amount of an antigen of Vibrio salmonicida, and an immunognically effective amount of an antigen of infectious salmon anaemia virus (ISAV).

[0030] In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio salmonicida serotype II. In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 01. In an embodiment, the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 02a. In an embodiment, the immunogenic composition does not comprise an antigen of Infectious pancreatic necrosis virus.

[0031] In an embodiment, the immunogenic composition further comprises an adjuvant. In an embodiment, the adjuvant is an oil-based adjuvant. In an embodiment, the immunogenic composition further comprises a veterinary acceptable carrier. In an illustrative aspect, a vaccine is provided. The vaccine comprises the immunogenic composition of any one of the immunogenic compositions described herein.

[0032] In an illustrative aspect, a method for inducing an immune response in fish is provided. The method comprise administering an immunogenic composition of any one of the immunogenic compositions described herein to a fish.

[0033] In an embodiment, the fish are salmonids. In an embodiment, the fish are Atlantic salmon.

[0034] In an embodiment, the administering is performed via an injection. In an embodiment, the injection injection is an intraperitoneal injection. In an embodiment, the intraperitoneal injection is performed one fin length ahead of the pelvic fin of the fish.

[0035] In an embodiment, the immune response is effective for prevention of one or more of infectious salmon anaemia, furunculosis, vibriosis, and cold water vibriosis in the fish.

[0036] The following numbered embodiments are contemplated and are non-limiting:

[0037] 1. An immunogenic composition comprising an immunogenically effective amount of an antigen of Moritella viscosa.

[0038] 2. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Moritella viscosa is of Canadian origin.

[0039] 3. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Moritella viscosa is not of Norwegian origin.

[0040] 4. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an immunogenically effective amount of an antigen of Aeromonas salmonicida.

[0041] 5. The immunogenic composition of clause 4, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Aeromonas salmonicida is of U.S. origin.

[0042] 6. The immunogenic composition of clause 4, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Aeromonas salmonicida is not of Norwegian origin.

[0043] 7. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I.

[0044] 8. The immunogenic composition of clause 7, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio anguillarum serotype I is of U.S. origin.

[0045] 9. The immunogenic composition of clause 7, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio anguillarum serotype I is not of Norwegian origin. 10. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II.

[0046] 11. The immunogenic composition of clause 10, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio anguillarum serotype II is of Canadian origin.

[0047] 12. The immunogenic composition of clause 10, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio anguillarum serotype II is not of Norwegian origin.

[0048] 13. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an immunogenically effective amount of an antigen of Vibrio ordalii.

[0049] 14. The immunogenic composition of clause 13, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio ordalii is of U.S. origin.

[0050] 15. The immunogenic composition of clause 13, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio ordalii is not of Norwegian origin.

[0051] 16. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an immunogenically effective amount of an antigen of Vibrio salmonicida serotype I.

[0052] 17. The immunogenic composition of clause 16, any other suitable clause, or any combination of suitable clauses, wherein the antigen of Vibrio salmonicida serotype I is of Norwegian origin.

[0053] 18. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an immunogenically effective amount of an antigen of infectious salmon anaemia virus (IS AV).

[0054] 19. The immunogenic composition of clause 18, any other suitable clause, or any combination of suitable clauses, wherein the antigen of ISAV is of Canadian origin.

[0055] 20. The immunogenic composition of clause 18, any other suitable clause, or any combination of suitable clauses, wherein the antigen of ISAV is not of Norwegian origin.

[0056] 21. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio salmonicida serotype II.

[0057] 22. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 01.

[0058] 23. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 02a.

[0059] 24. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Infectious pancreatic necrosis virus.

[0060] 25. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising an adjuvant.

[0061] 26. The immunogenic composition of clause 25, any other suitable clause, or any combination of suitable clauses, wherein the adjuvant is an oil-based adjuvant.

[0062] 27. The immunogenic composition of clause 1, any other suitable clause, or any combination of suitable clauses, further comprising a veterinary acceptable carrier.

[0063] 28. An immunogenic composition comprising an immunogenically effective amount of an antigen of Moritella viscosa. an immunogenically effective amount of an antigen of Aeromonas scilmonicida, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II, an immunogenically effective amount of an antigen of Vibrio ordalii, and an immunogenically effective amount of an antigen of Vibrio salmonicida.

[0064] 29. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, further comprising an antigen of one or more microorganisms selected from the group consisting of Aeromonas salmonicida, Vibrio anguillarum, Vibrio ordalii, Vibrio salmonicida, and infectious salmon anaemia virus (IS AV).

[0065] 30. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio salmonicida serotype II.

[0066] 31. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 01.

[0067] 32. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 02a.

[0068] 33. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Infectious pancreatic necrosis virus.

[0069] 34. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, further comprising an adjuvant.

[0070] 35. The immunogenic composition of clause 34, any other suitable clause, or any combination of suitable clauses, wherein the adjuvant is an oil-based adjuvant.

[0071] 36. The immunogenic composition of clause 28, any other suitable clause, or any combination of suitable clauses, further comprising a veterinary acceptable carrier.

[0072] 37. An immunogenic composition comprising an immunogenically effective amount of an antigen of Moritella viscosa, an immunogenically effective amount of an antigen of Aeromonas scilmonicida, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I, an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II, an immunogenically effective amount of an antigen of Vibrio ordalii, an immunogenically effective amount of an antigen of Vibrio salmonicida, and an immunognically effective amount of an antigen of infectious salmon anaemia virus (IS AV).

[0073] 38. The immunogenic composition of clause 37, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio salmonicida serotype II.

[0074] 39. The immunogenic composition of clause 37, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype 01.

[0075] 40. The immunogenic composition of clause 37, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Vibrio anguillarum serotype O2a.

[0076] 41. The immunogenic composition of clause 37, any other suitable clause, or any combination of suitable clauses, wherein the immunogenic composition does not comprise an antigen of Infectious pancreatic necrosis virus.

[0077] 42. The immunogenic composition of clause 37, any other suitable clause, or any combination of suitable clauses, further comprising an adjuvant.

[0078] 43. The immunogenic composition of clause 42, any other suitable clause, or any combination of suitable clauses, wherein the adjuvant is an oil-based adjuvant.

[0079] 44. The immunogenic composition of clause 37, any other suitable clause, or any combination of suitable clauses, further comprising a veterinary acceptable carrier.

[0080] 45. A vaccine comprising the immunogenic composition of any one of clauses 1 to 44.

[0081] 46. A method for inducing an immune response in fish comprising administering an immunogenic composition of any one of clauses 1 to 44 to a fish.

[0082] 47. The method of clause 46, wherein the fish are salmonids.

[0083] 48. The method of clause 46, wherein the fish are Atlantic salmon.

[0084] 49. The method of clause 46, wherein the administering is performed via an injection.

[0085] 50. The method of clause 49, wherein the injection injection is an intraperitoneal injection. 51. The method of clause 50, wherein the intraperitoneal injection is performed one fin length ahead of the pelvic fin of the fish.

[0086] 52. The method of clause 46, wherein the immune response is effective for prevention of one or more of infectious salmon anaemia, furunculosis, vibriosis, and cold water vibriosis in the fish.

[0087] EXAMPLE 1

[0088] Exemplary Process for Making Formulations

[0089] The instant example provides exemplary processes by which an immunogenic composition of the present disclosure can be manufactured.

[0090] A first process generally includes propagation, inactivation, blending with adjuvant, and release testing. For instance, bacterial working seeds can be aseptically inoculated into fermentation vessels containing production media (e.g., TSB + NaCl, Vibrio media, etc.). Thereafter, the inoculation can be scaled up to production size vessels at appropriate temperatures for incubation times allowing for maximal bacterial yields. Agitation and aeration can be used as needed to assist with growth. Glucose can be added to the cultures to increase biomass. Following fermentation, bacterial antigens can be inactivated by the addition of formalin, then mixed and held for a minimum period of time. Inactivated cultures can be concentrated to target inputs and then blended with adjuvant (e.g., sorbitan sesquioleate, mineral oil, polysorbate 80, and the like) and emulsified. The resulting immunogenic composition product is agitated prior to filling of product containers.

[0091] A second process generally includes propagation, inactivation, blending with adjuvant, and release testing. For instance, bacterial working seeds can be aseptically inoculated into fermentation vessels containing production media (e.g., TSB + NaCl, Vibrio media, etc.). Thereafter, the inoculation can be scaled up to production size vessels at appropriate temperatures for incubation times allowing for maximal bacterial yields. Agitation and aeration can be used as needed to assist with growth. Glucose can be added to the cultures to increase biomass. If viral working seeds are to be included in the immunogenic composition, the viral working seed can be inoculated onto a cell line (e.g., CHSE-214s) and allowed to propagate at appropriate temperatures for incubation periods resulting in maximal viral yields. Bacterial and viral antigens can be then inactivated by the addition of formalin, then mixed and held for a minimum period of time. Inactivated cultures (bacterial and viral) can be concentrated to target inputs and then blended with adjuvant (e.g., sorbitan sesquioleate, mineral oil, polysorbate 80, and the like) and emulsified. The resulting immunogenic composition product is agitated prior to filling of product containers. For instance, for Forte M, bacterin fractions include the following inactivated organisms: Aeromonas scilmonicida sub-species scilmonicida (As27), Moritella viscosa (FFA532), Vibrio anguillarum serotype 01 (ValOl), Vibrio anguillarum serotype 02 (Val23), Vibrio ordalii (Val02), Vibrio scilmonicida serotype 01 (VslO).

[0092] For instance, for Forte VII, a viral fraction is added to the bacterin fractions. The Forte VII composition includes the following organisms: Aeromonas salmonicida sub-species salmonicida (As27), Moritella viscosa (FFA532), Vibrio anguillarum serotype I (ValOl), Vibrio anguillarum serotype II (Val23), Vibrio ordalii (Val02), Vibrio salmonicida serotype I (VslO), and Infectious Salmon Anaemia Virus (ISA-12-1).

[0093] EXAMPLE 2

[0094] Efficacy Evaluation

[0095] Immunological compositions and vaccines have been shown to provide crossprotection between bacteria, including across different geographical regions. The instant example provides evidence of cross-protection for Norwegian isolates. In particular, a Pentium Forte Plus (PFP) ILA comprising Norwegian Vibrio spp. isolates (Val30, Val31, VslO) demonstrated cross-protection against Chilean Vibrio ordalii. After 650 degree days of immunization and subsequent intraperitoneal challenges, the absolute risk reduction of mortality in PFP ILA vaccinated fish was demonstrated to be 61.7%, and at 1500 degree days the absolute risk reduction was shown to be 50%.

[0096] In another project, an immunological composition formulation included the five bacterial isolates as contained in PFP ILA. Results similarly indicated strong cross-protection in fish.

[0097] First, multivalent dosing studies at Veso Aqualab Norway utilized challenge isolates. Three sets of experiments were undertaken: one each for Vibrio anguillarum serotype 01, 02a, and for Vibrio salmonicida. Data demonstrated that only the VslO experiments produced a sub-potent result.

[0098] A second multivalent dosing study using a Vai 31 challenge (Vibrio anguillarum serotype 02a) did not detect a sub-potent dose. For instance, negative control mortality was observed to be slightly under 60%, and a batch produced with active concentrations at the limit of detection for all five of the potency assays was statistically equivalent to doses 10X higher.

[0099] A third multivalent dosing study using a Vai 30 challenge (Vibrio anguillarum serotype 01) did not detect a sub-potent dose. This study included batches produced at the proposed minimum for all antigens, and then included sub-potent batches so that i) the concentration of Val30 at the limit of detection for the Val30 assay, ii) the concentration of Val30 and Val31 at the limits of detection for the Val30 and Val31 assays, and iii) the concentration of Val30, Val31, and VslO at the limits of detection for the Val30, Val31, and Vs 10 assays. Results are shown in Figure 1.

[0100] In conclusion from the described studies, analyses indicated that cross-protection existed from the Vibrio spp. isolates, and possibly also from the As27 and Vvil isolates. Without being bound by any theory, one of the Vibrio anguillarum isolates, or perhaps both, may not be required.

[0101] EXAMPLE 3

[0102] Efficacy Evaluation

[0103] The instant example provides evaluation of cross-protection between the North American and European isolates of Mor ite I la viscosa. For instance, the use of Norwegian Moritella viscosa (Vvi 1 antigen) in the vaccine Pentium Forte Plus (PFP) against challenges using Canadian isolates of Moritella viscosa was evaluated. The Norwegian isolate did provide some protection, though the superior efficacy in these trials came from fish vaccinated with isolate FFA532. Figure 2 provides a table comparing the analyses of PFP compared to FFA532 bacterin (vaccine antigen isolate from New Brunswick), FFA371 bacterin (challenge isolate from British Columbia), and Vvl antigen in comparison to saline (control).

[0104] The Moritella viscosa FFA532 bacterium, is a Canada Atlantic isolate, which was isolated from a clinically diseased Atlantic salmon at Cooke Aquaculture site, in Bay of Fundy, New Brunswick, Canada, in 2012.

[0105] The Moritella viscosa FFA371 bacterium, is a Canada Pacific isolate, which was isolated from a clinically diseased Atlantic salmon in British Columbia, Canada, in 2014.

[0106] Furthermore, it has been shown that European and Canadian isolates were generally similar with respect to antigen profile, though with noticeable differences between the Canadian M. viscosa isolates and a reference European isolate Mv2 existed (in particular, protein bands < 30 kDa). Western blots probed with Mv2 -derived antibodies exhibited immunoreactivity to the bands across both Canadian isolates, and were specific to M. viscosa Further, they did not cross-react with other wound developing species commonly cultured in Canada (e.g. Aliivibrio wodanis).

[0107] The reference genome of Norwegian isolate LFI 5006 from NCBI (NZ_FPLGO 1000000) was used for bioinformatic analysis. In total, there were 12 other WGS entries, which were used in the phylogenetic analysis, and included two Canadian isolates, Vvi7 and Vvi 11. The remaining entries were from Norway, Iceland, and the UK.

[0108] When evaluating the FFA532 and FFA371 isolates for known M. viscosa virulence factors, both contained sequences for an extracellular metallopeptidase (mvpl gene) that is a known extracellular vibriolysin.

[0109] Figure 3 provides a dendrogram and confirms the relation of Canadian to Icelandic M. viscosa isolates, followed by Norwegian isolates from trout, in agreement with previous pan-Atlantic evaluations.

Claims

CLAIMS1. An immunogenic composition comprising an immunogenically effective amount of an antigen of Moritella viscosa. wherein the antigen of Mor ite I la viscosa is of Canadian origin.

2. The immunogenic composition of claim 1, further comprising an immunogenically effective amount of an antigen of Aeromonas salmonicida. wherein the antigen of Aeromonas salmonicida is of U.S. origin.

3. The immunogenic composition of claim 1, further comprising an immunogenically effective amount of an antigen of Vibrio anguillarum serotype I, wherein the antigen of Vibrio anguillarum serotype I is of U.S. origin.

4. The immunogenic composition of claim 1, further comprising an immunogenically effective amount of an antigen of Vibrio anguillarum serotype II, wherein the antigen of Vibrio anguillarum serotype II is of Canadian origin.

5. The immunogenic composition of claim 1, further comprising an immunogenically effective amount of an antigen of Vibrio ordahi. wherein the antigen of Vibrio ordalii is of U.S. origin.

6. The immunogenic composition of claim 1, further comprising an immunogenically effective amount of an antigen of Vibrio salmonicida serotype I, wherein the antigen of Vibrio salmonicida serotype I is of Norwegian origin.

7. The immunogenic composition of claim 1, further comprising an immunogenically effective amount of an antigen of infectious salmon anaemia virus (ISAV), wherein the antigen of ISAV is of Canadian origin.

8. The immunogenic composition of claim 1, further comprising an adjuvant, wherein the adjuvant is an oil-based adjuvant.

9. A vaccine comprising the immunogenic composition of any one of claims 1 to 8.

10. A method for inducing an immune response in fish comprising administering an immunogenic composition of any one of claims 1 to 8 to a fish, wherein the fish are Atlantic salmon.

11. The method of claim 10, wherein the administering is performed via an injection, and wherein the injection is an intraperitoneal injection.

12. The method of claim 10, wherein the immune response is effective for prevention of one or more of infectious salmon anaemia, furunculosis, vibriosis, and cold water vibriosis in the fish.

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