Biochemical effects of encapsulated radiovaccine via alginate nanoparticles as useful strategy for booster in immunized rainbow trout against Ichthyophytirius multifiliis

ABSTRACT

Background: The Ichthyophthirius multifiliis is one of the most important protozoan pathogens of farmed and wild fish populations. The vaccination against I. multifiliis can be considered as an alternative to chemical treatments. There are three routes of vaccination; the injection, immersion and oral administration. Oral immunization would be a good candidate since handling fish is not required, it is a not stressful method and it needs less time and labor. In this study a nanoparticle system for protection of radiovaccine and efficient oral vaccine delivery to the intestinal tract against I. multifiliis was tested in rainbow trout.Materials, Methods & Results: Fifty rainbow trout (40 - 50 g) were infected with I. multifiliis via live trophont, trophont were collected with 200-mesh sieve. After collection, dose of gamma ray (170 Gray) was used for irradiation of parasite. Commercial Ergosan was suspended in sterile 0.15 M (pH 7.2) and sonicated. Remaining powder was irradiated by gamma irradiator. The alginate nanoparticle encapsulated radiovaccine was achieved by the addition of PBS (1 mL) to the alginate nanaoparticle solution (4 mL) plus radiovaccine (37˚C, pH 7.5). Fish were distributed equally into 5 groups (60 fish/aquarium). In this study, elevated levels of WBC was found in fish immunized with non-capsulated and encapsulated radiovaccine at 20 days after challenge (P < 0.05). No significant differences in haematocrit and RBC were found among all of groups (P < 0.05). Also, plasma total protein level was found to decrease in vaccinated fish with non-capsulated radiovaccine at 7 and 20 days after challenge. Significant decrease in glucose level was shown in immunized rainbow trout with encapsulated radiovaccine (P < 0.05). A significant increase in plasma glucose level was shown in rainbow trout challenged with live trophonts at 7 days after challenge (P < 0.05).[...]