Study On The Preparation And Immune Effect Of Vibrio Parahaemolyticus Oral Sustained Release Vaccine

Vibrio parahaemolyticus is a common pathogen of aquaculture animals.It can cause Vibrio disease in various aquaculture animals such as fish,shrimp and shellfish,resulting in huge economic losses.At present,the treatment of Vibrio disease of aquatic animals is still using antibiotics and disinfectants.However,the large scale use of drugs will lead to the problems of aquatic products residues,water pollution and emergence of drug-resistant strains.The study of vaccines may provide new ideas for the prevention and treatment of Vibrio disease.Oral immunization with easy to operate,safe and easy,not by individual fish size restrictions and other advantages have attracted much attention,but because the original oral vaccine immune to stomach acid and digestive enzymes in the foregut was destroyed,and lead to the decomposition and absorption of immune efficacy.In this study,we used the feed as carrier to adsorb the prepared Vibrio parahaemolyticus inactivated vaccine.We used ethyl cellulose,hydroxypropyl methyl cellulose and citric acid three ethyl ester as coating materials to prepare the slow released oral vaccine.The sustained release effect of sustained-release vaccine was detected by real-time quantitative PCR.The results showed that the release amount of Vibrio parahaemolyticus from sustained release vaccine was 27.6%,36.2%,23.3%,31.5% and 29% at1,2,5,10,15 min and other time points,respectively.The results showed that the vaccine had good sustained release effect.By oral immunization of turbot by sustained-release oral vaccine preparation,antibody titer began to rise from the immune after second weeks after immunization in fourth weeks to reach 1:256-512,using Vibrio parahaemolyticus on immunity of turbot poisoningattack test,slow-release oral vaccine immune protection of turbot was 51.71%,and the the free fish serum could significantly inhibit the growth of Vibrio parahaemolyticus.The above results showed that the sustained release oral vaccine prepared by our experiment could slow down the release of antigen and protect the immune function of turbot.