High efficacy and economical procedure of oral vaccination against Lactococcus garvieae/Streptococcus iniae in rainbow trout (Oncorhynchus mykiss).

The present study was aimed to examine the efficacy of chitosan-alginate coated vaccines against pathogenicity of Lactococcus garvieae and Streptococcus iniae in rainbow trout. Fish were divided into four groups including: Group A: fish immunized by chitosan-alginate coated vaccine, Group B: fish immunized by non-coated vaccine, Group C: fish feed by chitosan-alginate coated pellets without vaccine and Group D: fish feed by basic diet (non-coated and without vaccine). In groups A and B, the vaccination was carried out for 14 days and after that supplemented with fundamental diet (control diet). Comparable to groups A and B, fish of group C were also fed 14 days with test diets and after that fed control food. On day 0, 20, 40 and 60 of the experiment, serum samples were given. Fish have been challenged with live L. garvieae and S. iniae after 60 days. The levels of bactericidal activity and complement activity among innate immunity components extended on day 20 of the research and after that decreased in group A and B (P < 0.05) all through the examination. The relative expression of IL-6 and IgM in groups A and B extended on examination day 20. The expression of these genes illustrated no advancements in different groups in during the examination (P > 0.05). In group A, the serum antibody titer against L. garvieae and S. iniae broadly raised on day 40 and 60 of examination, whereas in group B, the immune response titer against S. iniae and L. garvieae illustrated a significant elevation on day 60 of the trial (P < 0.05). After challenge with live bacteria, survival rate of 83 ± 9.1%(challenged with S. iniae) and 72.18 ± 9.8% (challenged with L. garvieae) were gotten independently in group A, which were higher than survival of other exploratory groups (P < 0.05). In conclusion, the results of the present examination appear that the orally vaccination of rainbow trout with chitosan-alginate covered vaccine stimulates immunity system and also efficiently protects rainbow trout against Lactococcus garvieae and Streptococcus iniae.

Valuable method for production of oral vaccine by using alginate and chitosan against Lactococcus garvieae/Streptococcus iniae in rainbow trout (Oncorhynchus mykiss).

The effectiveness of ionotropic gelation method (by combining alginate and chitosan) vaccine against Lactococcus garvieae and Streptococcus iniae was examined in rainbow trout. Fish were separated into four groups and fed the distinctive examined feeds. Our groups were included: A) fish immunized by chitosan-alginate coated vaccine, B) fish immunized by non-coated vaccine, C) fish feed by chitosan-alginate coated pellets without vaccine and D) fish feed by basic diet (non-coated and without vaccine). In groups A and B, the vaccination was carried out for 14 days. Fish of group C, like groups A and B were fed 14 days with pellets covered with chitosan-alginate without vaccine and a short time later they were fed with control diet. On day 0, 20, 40 and 60 of the trial, serum samples were extracted. Fish were challenged with L. garvieae and S. iniae after 60 days of research. Innate immunity components containing complement activity, total protein and IgM appeared no significant changes nearly in all groups during the 60 days that the examination finished. Although, bactericidal activity and lysozyme activity demonstrated a significant increase on days 20, 40 and 60 in group A compared to control groups (C and D) (P < 0.05) and similar results about the blood respiratory burst activity just on days 20 and 40 were obtained. Also, the relative expression of IL-6 of group A, was significantly higher compared to all of other groups (B, C and D) on days 20 and 60 of experiment (P < 0.05). The same results were obtained about the relative expression of IgM. The serum ELISA antibody titer against L. garvieae, increased significantly on days 20 and 40 of experiment in fish immunized by chitosan-alginate coated vaccine (Group A) compared to control groups (C and D)(P < 0.05) while the result of ELISA test against S. iniae was significantly higher on days 40 and 60 of experiment in group A compared to groups B, C and D (P < 0.05). After challenge with these two live bacteria (S. iniae and L. garvieae), a survival rates of 76.67 ±â€¯5.77% (challenged with S. iniae) and 66.67 ±â€¯5.77% (challenged with L. garvieae) were seen in group immunized with chitosan-alginate coated vaccine (Group A), which were higher than survival rates gotten in other trial groups (P < 0.05). The consequences of the present experiment show that the oral vaccination of rainbow trout with improved chitosan-alginate (via ionotropic procedure) (group A) properly secures this important fish against Lactococcus garvieae and Streptococcus iniae.

Efficacy of a Eudragit L30D-55 encapsulated oral vaccine containing inactivated bacteria (Lactococcus garvieae/Streptococcus iniae) in rainbow trout (Oncorhynchus mykiss).

The efficacy of a Eudragit L30D-55 encapsulated vaccine against Lactococcus garvieae and Streptococcus iniae was investigated in rainbow trout. Fish were divided into four groups and fed the different experimental feeds. Groups were: A) fish immunized by Eudragit-coated pellets containing vaccine, B) fish immunized by vaccine-coated pellets without Eudragit, C) fish fed Eudragit-coated pellets without vaccine and D) fish fed pellets without vaccine orEudragit (control group). In groups A and B, the vaccination was conducted for 14 days. Similar to groups A and B, fish of group C were fed 14 days with pellets coated with Eudragit and afterwards they were fed control diet. Serum samples were taken on day 0, 20, 40 and 60 of the experiment. After 60 days, fish were challenged with L. garvieae and S. iniae. In almost all groups, innate immunity components including alternative complement activity, lysozyme activity, bactericidal activity, IgM and total protein showed no significant changes during the 60 days that the experiment lasted. However, the blood respiratory burst activity and lysozyme activity showed a significant increase on day 20 of experiment in groups B and D respectively (P < 0.05). The relative expression of immune-related genes including IL-6 and IgM genes was higher in vaccinated fish, with the highest expression in those immunized by Eudragit-coated pellets (Group A). In addition, the relative expression of IL-6 and IgM peaked on day 20 but decreased on day 60 in vaccinated groups. The ELISA antibody titer against L. garvieae increased from day 20 and peaked on day 60 of experiment (P < 0.05). Also, the antibody titer against L. garvieae was higher in fish immunized by Eudragit-coated pellets (Group A) compared to fish of group C and control. After bacterial challenge, a survival percentages of % 85 ±â€¯7.07% (challenged with S. iniae) and % 72.21 ±â€¯7.8% (challenged with L. garvieae) were observed respectively in groups immunized with pellets coated with Eudragit L30D-55 (Group A), which were higher than survival percentages obtained in other experimental groups (P < 0.05). The results of the present study demonstrate that the oral administration of Eudragit L30D-55-encapsulated vaccine appropriately protects rainbow trout against Lactococcus garvieae and Streptococcus iniae.

Immune response in spirlins (Alburnoides bipunctatus, Bloch 1782) infested by Ligula intestinalis parasite.

Ligula intestinalis parasite is a cestode that can cause remarkable damages to fishes. SDS-PAGE is one of the methods that can be used to determine the immune serum band polymorphism and immune responses in fishes infested by Ligula intestinalis. This study reports the results of an investigation conducted using SDS-PAGE focusing on immune serum band polymorphism and on the reaction of the immune system in spirlins (Alburnoides bipunctatus) infested by pleurocercoids of Ligula intestinalis parasite. Serum samples from infested spirlins revealed a polymorphism band which differed from that reported in sera of roaches (Rutilus rutilus), a species of the same Cyprinidae family.