Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/6/2004
Publication Date: 1/17/2005
Citation: Klesius, P.H., Evans, J.J., Shoemaker, C.A., Pasnik, D.J., Lim, C.E. 2005. Dietary strategies to improve vaccination efficiency. Aquaculture America Conference.
Technical Abstract: Cohabitation pathogen challenge is regarded as one of the best models for evaluation of dietary strategies for increased vaccine potency that most mimics natural conditions. A number of techniques exist for marking fish. These techniques include fin clips, percutaneous tags, visible implant tags, and coded wire tags. These techniques are generally not acceptable for marking large numbers of fish and small size fish. Fin clips, tags, electric, and freeze brands can also result in compromised protection of the body surface, stress, and behavioral effects. More importantly, these invasive fish marking techniques may promote horizontal transmission of infection between the cohabitated fish population, especially in the presence of severely infected fish. Thus, an alternative technique of marking fish is needed to investigate successful development of an experimental cohabitation vaccination and challenge model. A non-invasive and non-lethal marking technique to differentiate between sham-vaccinated (control) and vaccinated cohabitants appears to be the use of the fluorescent chromophore, calcein. Nutritional strategies may be more successfully evaluated when the control fish are marked with calcein and cohabitated with unmarked vaccinated fish fed diets that may enhance the acquired immunity against the specific pathogen. Many investigators have used in vitro non-specific and specific immune cells assays to determine the affect of dietary strategies on immunity to pathogens. However, results of in vitro immune responses correlates often differ with the results of the in vivo pathogen challenge experiments. The use of the cohabitation vaccine evaluation model described in this paper will provide for the discovery and the development of marking strategies to help evaluate acquired immune responses in vaccinated fish that more closely mimics natural conditions.