Immunization of rainbow trout (Oncorhynchus mykiss) with alginate microparticles containing inactivated Flavobacterium psychrophilum

Abstract

In this study, survival rate of rainbow trout (Oncorhynchus mykiss), fed for 28 days with sodium alginate microparticles containing Flavobacterium psychrophilum inactivated with formalin, against diseases is determined. The fishes are divided into six groups in terms of feeding method; control group, sodium alginated group, fishmeals including 2.5 and 10 mg/g F. psychrophilum , fishmeals of 2.5 and 10 mg/g F. psychrophilum encapsulated with alginate microparticles. Following by oral immunization, experimental infection is created by bathing them in 3.2x107 CFU/ml F. psychrophilum for 1 hour at 53. and 87. days and relative percent survival (RPS) rates are determined. At fifth third day of immunization, while mortality rate of 79.2% is observed for control group, the highest RPS value of 62.1 is found for the group fed with 10 mg/g F. psychrophilum alginate microparticles. At eighty seventh day in infectious F. psychrophilum , while control group’s mortality rate is found 74.8, the rest of groups RPS rates are determined 30.48, 35.3, 40.10, 50.25 and 56.68 respectively. Based on these findings, it can be asserted that protectiveness of fishes, fed with fishmeal encapsulated with sodium alginate microparticles by using inactivated bacterial cells, is not achieved at a sufficient level. Keywords: Rainbow trout, Flavobacterium psychrophilum, sodium alginate microparticles, relative percent survival rates