Vaccine development for winter ulcer disease, Vibrio viscosus, in Atlantic salmon, Salmo salar L.

Abstract

Coldwater Vibrio species isolated from Atlantic salmon, Salmo salar L., during winter ulcer disease outbreaks at saltwater sites in Norway and Iceland were characterized phenotypically, tested for virulence, and used to evaluate the efficacy of multivalent, oil‐adjuvanted vaccines. The intraperitoneal (i.p.) injection of rainbow trout, Oncorhynchus mykiss (Walbaum), in fresh water with one bacteria species isolated during winter ulcer outbreaks, V. ‘viscosus’, produced rapid mortality and disease signs which resembled those observed during natural outbreaks [105 colony‐forming units (cfu) fish−−1]. Another species, V. ‘wodanis’, was not virulent to rainbow trout (103–106 cfu fish−−1). Although vaccination of rainbow trout with a mineral‐oil‐adjuvanted, injectable vaccine containing V. anguillarum (serotypes 01 and 02), V. salmonicida and Aeromonas salmonicida did not provide protection against injection challenge with V. viscosus, vaccines which included V. viscosus produced significant protection in Atlantic salmon and rainbow trout. Atlantic salmon vaccinated with an oil‐adjuvanted vaccine containing V. viscosus, V. wodanis and atypical A. salmonicida produced a relative percentage survival (RPS) of 97% when challenged i.p. with V. viscosus, demonstrating cross‐protection between strains from Iceland and Norway. Short‐term efficacy was demonstrated in rainbow trout by injection challenge at 21 and 43 days post‐vaccination with an oil‐adjuvanted vaccine containing V. viscosus, V. anguillarum (01/02), V. salmonicida and A. salmonicida, which produced an RPS of 96–99%. Rainbow trout challenged with V. viscosus at 52 and 362 days post‐vaccination produced an RPS of 93% and 79%, indicating that vaccination provided long‐term protection. In a similar manner, rainbow trout injected i.p. with 0.2 mL of a vaccine containing the five bacteria species and infectious pancreatic necrosis virus produced a 90% RPS when challenged with V. viscosus 66 days later. The high RPS under a severe challenge burden, along with disease signs in experimental freshwater challenges which resembled the saltwater disease condition, indicated that V. viscosus is a contributing factor to winter ulcer and that vaccination will protect against the disease.

Previously unrecognised division within Moritella viscosa isolated from fish farmed in the North Atlantic

“…Isolates from Atlantic salmon in Norway must therefore account for the overwhelming majority of clinical M. viscosa isolates on a worldwide basis. Despite the antigenic differences identified during the present study and by Heidarsdóttir et al (2008), crossprotection has been reported between Icelandic (presumed variant) and Norwegian (typical) strains (Greger & Goodrich 1999). The previous assumption of homogeneity may therefore not have been as significant in relation to protection of vaccinated stocks as it otherwise might have been.…”

Antigen profiles of the fish pathogen Moritella viscosa and protection in fish

“…2003). However, cross protection between an Icelandic and a Norwegian strain has been reported (Greger and Goodrich 1999).…”

Effects of different batches of Neoparamoeba perurans and fish stocking densities on the severity of amoebic gill disease in experimental infection of Atlantic salmon, Salmo salar L.

“…Several challenge models have been established for experimental infections in fish by a range of bacteria and viruses with exposure methods including direct injection of the pathogen (e.g. Nordmo & Ramstad 1997; Greger & Goodrich 1999; Aranguren, Tafalla, Novoa & Figueras 2002; Bowden, Smail & Ellis 2002; Thoulouze, Bouguyon, Carpentier & Bremont 2004; Björnsdóttir, Gudmundsdóttir, Bambir & Gudmundsdóttir 2005; Byon, Ohira, Hirono & Aoki 2005; Caipang, Takano, Hirono & Aoki 2006), cohabitation of naïve fish with infected individuals (e.g. Nordmo & Ramstad 1997; Jones & Groman 2001; López‐Dóriga, Smail, Smith, Doménech, Castric, Smith & Ellis 2001; Bowden et al 2002; Klesius, Evans, Shoemaker & Pasnik 2006) and water‐borne exposure (e.g.…”