The invention discloses a preparation method and application of an aquatic rahnella oral microcapsule sustained-release vaccine for fish, and relates to the field of
fishery biological medicines.
Sodium alginate and
liquid paraffin which are two kinds of insoluble liquid are utilized, a stable
emulsion is formed through a high-stirring-speed emulsifier, then the
sodium alginate and
calcium ions are physically cross-linked to be fixed, then a layer of
chitosan coating is wrapped, and the rahnella aquatilis oral micro-
capsule sustained-release vaccine is prepared, and the average particle size is 1-5 microns. The
coating rate of Rahnella aquatica is measured by using a spectrophotometer after the Rahnella aquatica is subjected to decapsulation with decapsulation liquid, and the
coating rate of thalli is 36.6%; the results of a zebra fish challenge experiment show that the protection rate of the vaccine is 92%, and the safety of the vaccine is 100%. In order to further clarify the
efficacy of the vaccine, the detection of oral vaccine fish blood indexes and
immune related genes such as TLR5, TNFa and uPAR has obvious up-regulated expression, compared with a non-immune group, the up-regulated expression in liver, head and
kidney and
muscle tissues is higher, and a related basis is provided for elaborating the
pathogen and host PAMPs-PRRs process. The results show that the oral micro-
capsule sustained-release vaccine has a good
disease-resistant immune effect, and a foundation is laid and a thought is provided for development and application of fish oral vaccines. Therefore, the invention develops a novel
sodium alginate
microsphere oral sustained-release vaccine aiming at rahnella aquatica, and provides a new strategy for solving the problems of
disease treatment and
drug resistance of rahnella aquatica in
aquaculture.