Efficacy of Immersion and Intraperitoneal Vaccination Against Yersinia Ruckeri and the Effects on Immune Response in Rainbow Trout, Oncorhynchus Mykiss

Abstract

In this study, the effectiveness of vaccination against Yersinia ruckeri, using an autogenous bacterin, in rainbow trout (Oncorhynchus mykiss) was assessed. In addition, the immune response detected by enzyme-linked immunosorbent assay (ELISA) was evaluated. Rainbow trout were vaccinated at 25 grams mean body weight by standard bath immersion and intraperitoneal (i.p.) injection (saline-based injection or oil-based adjuvant injection). Bath-challenges occurred on days 42, 101, 181, 286, and 381 post-vaccination. Plasma samples were collected pre-challenge and fourteen days post-challenge for antibody titer analysis. Antibody kinetics were followed prior to first challenge. Relative percent survival (RPS) ranged from 98.96% to 96.85% and did not statistically differ among vaccinated groups. Increased antibody titer was identified in the oil-based adjuvant injection vaccinated group however, statistical significance among vaccinated groups was not determined.