Optimization of production process of Aeromonas veronii CA07 strain inactivated vaccine / 中国生物制品学杂志

@#Abstract：Objective To optimize the production process of inactivated vaccine of Aeromonas veronii（AV）CA07 strain. Methods The fermentation culture process of AV CA07 strain liquid was determined through the optimization of the culture time（2～16 h），medium（optimized fermentation medium，LB medium and NB medium）and fermentation conditions（in⁃ oculation amount of 1%，5%，10% and 15%；ventilation rate of 2，4，6 and 8 L／min and fermentation time of 6，8，10 and 12 h）. The optimal inactivation process was determined through the comparison of the final concentration of formalde⁃ hyde solution（0. 10%，0. 20%，0. 30% and 0. 40%），inactivation temperature（28 and 37 ℃）and inactivation time（24， 48 and 72 h）. The large⁃scale production process of inactivated vaccine of AV CA07 strain in 500 L fermentor was estab⁃ lished and the prepared vaccines were tested for safety and immunogenicity. Results The optimal inoculation amount of AV CA07 strain was 5%，ventilation rate was 4 L／min and culture time was 10 ~ 12 h. The optimal inactivation condition was adding formaldehyde solution with final concentration of 0. 30% incubating at 37 ℃ for 24 h. The number of viable bacteria in the fermentation broth of AV CA07 strain prepared in 500 L fermentor was more than 8 × 109 CFU／mL. All crucian carps immunized with the inactivated vaccine by abdomen survived. After challenge，the relative immune protection rate was more than 90%. Conclusion AV CA07 strain inactivated vaccine prepared by optimized production process showed good safety and immunogenicity.

Study on Immune Response of Organs of Epinephelus coioides and Carassius auratus After Immersion Vaccination With Inactivated Vibrio harveyi Vaccine.

Immersion vaccination relies on the response of fish mucosa-associated lymphoid tissues, the Crucian carp (Carassius auratus) and Grouper (Epinephelus coioides) were researched in this paper to examine local mucosal immune responses and associated humoral system responses following immersion vaccination. We administered 1.5 × 107 CFU/ml formalin-inactivated Vibrio harveyi cells and measured mucus and serum antibody titers as well as IgM, MHC II mRNA levels in immune organs. The mucosal antibody response preceded the serum response indicating a role for local mucosal immunity in immersion vaccination. IgM and MHC II mRNA levels were relatively greater for the spleen and head kidney indicating the importance and central position of systemic immunity. Expression levels were also high for the gills while skin levels were the lowest. IgM and MHC II mRNA levels were altered over time following vaccination and the hindgut, liver and spleen were similar indicating a close relationship, so the absolute value of r is used to analyze the correlation among different organs immunized. It can be inferred the existence of an internal immune molecular mechanism for Immune synergy hindgut-liver-spleen, from the peak time (14th day), the relative ratio of genes expression in the same tissues between the immunized grouper and the control group (26 times), and Pearson correlation coefficient (0.8<|r|<1). Injection challenges with live V. harveyi indicated that the relative protection rates for the crucian carp and Grouper was basically the same at 44.4% and 47.4%, respectively. It is believe that crucian carp may be used as a substitute for the valuable grouper in immunity experiment, just from aspect of the relative percent survival (RPS) and how it changes with time. But they were not consistent about the IgM mRNA expression between that of crucian carp and grouper after immersion the Vibrio vaccine.

[Biological characteristics and histopathological observation of Vibrio alginolyticus from diseased fish].

OBJECTIVE: Ulcer disease is one of the most serious diseases and a common problem in various stages marine culture including Epinephelus coioides culture of southern China. The isolation and identification of pathogenic bacteria from E. coioides will be useful for monitoring of drug resistance and controlling the outbreak and spread of ulcer disease in E. coioides. The purpose of this study was to characterize the pathogen of E. coioides. METHODS: The pathogenic bacteria separated from the liver and kidney of diseased fish were identified through pure culture, artificial infection, automatic tests in bacteriology automatic identification, drug sensitive tests, morphometry, and physiological and biochemical determination. RESULTS: The strains were characterized and identified as Vibrio alginolyticus. Two strain were selected for virulence tests and all the moribund/dead fish exhibited ulcer disease as that observed in natural outbreak. Drug sensitive tests show that V. alginolyticus was highly resistant to 3 agents including penicillin, whereas sensitive to 5 agents including chloromycetin. Histopathological changes were mainly shown as cell degeneration and necrosis of gill, liver and kidney, and alterative inflammation as a result of inflammatory cell infiltration in the diseased tissue. CONCLUSION: The biochemical, physiological tests confirm that V. alginolyticus is the pathogen causing E. coioides vibriosis. The multi-drug resistance among V. alginolyticus suggests strengthened monitoring of outbreaks of V. alginolyticus caused disease in E. coioides culture.