Effects of vaccination against Yersinia ruckeri on oxidative stress biomarkers and liver and heart biochemistry in rainbow trout (Oncorhynchus mykiss)

Abstract To determine the effects of vaccination against Yersinia ruckeri on the health condition of rainbow trout, Oncorhynchus mykiss (Walbaum) in general, and oxidative stress biomarkers and metabolic parameters specifically, as well as to identify mechanisms that underpin the susceptibility of fish to vaccination, we compared the liver and heart function, and the oxidative mechanism underlying those effects, by detecting relevant lipid peroxidation and protein oxidation biomarkers, as well as aerobic-anaerobic metabolism in trout immunized against Y. ruckeri at 30 days post-vaccination and in healthy individuals. In our study, hepatic aminotransferase activities were positively associated with the oxidative stress biomarkers in the trout vaccinated against Y. ruckeri. Moreover, similar associations were observed in the cardiac tissue of the immunized trout. Decreased aldehydic and ketonic derivatives of oxidatively modified proteins and the reduction of aminotransferase and lactate dehydrogenase activities were sensitive to the vaccination of trout against Y. ruckeri and may potentially be used as biomarkers in evaluating vaccine effects in the liver of rainbow trout. Understanding the role of biochemical changes in the tissues of vaccinated trout has important implications for understanding of the complex physiological changes that occur in immunization, and also for improving aquaculture practices to maximize tissue growth and the health of vaccinated trout.