Evaluation of Specific Immunogenicity of Aeromonas Hydrophila Injection Biofilm Vaccine in Common Carp

Abstract

Introduction: Common carp is considered one of the most important hydrothermal fishes in the world, and in Iran, hydrothermal fish has the highest production of cultured fish, and in this regard, Khuzestan has a high potential for hydrothermal fish breeding. One of the methods of protection and slow release of vaccine antigens is the use of biodegradable natural polymers such as chitin in the bacterial biofilm substrate.
Materials & Methods: In this study, biofilm vaccine of Aeromonas hydrophila bacteria was carried out by culturing the bacteria in Trypticase Soya Broth media (0.225% W/V) along with chitin (0.3% W/V) for 4 days in a shaker incubator. Then the bacteria were washed with sterile phosphate buffer and inactivated by heat. A number of common carp weighing 33±6.8 g was randomly divided into 5 equal treatments and each treatment was replicated as follows: the first to fourth treatments were respectively biofilm vaccine, bacterin, chitin and chitin + Trypticase Soya Broth media. The intra peritoneal injection method was done, the 5th treatment without vaccine administration was considered as the control group. Samplings of fish serum were done on days 0, 20, 40 and 60.
Results: The anti-Aeromonas hydrophila antibody level in the samples was evaluated by ELISA method and by monoclonal antibody (P<0.05).
Conclusion: The results showed that biofilm and bacterin vaccine had a significant increase in antibody titer compared to other treatments in all days, although the antibody titer of Biofilm vaccine was higher than bacterin in all days, and on the 60th day, biofilm vaccine has been significant increase rather than bacterin and other treatments.