中华鳖嗜水气单胞菌微球缓释疫苗的研制及免疫效果

Preparation of Aeromonas hydrophila sustained release microspheres vaccine and its immune effectiveness

为通过免疫防治途径控制嗜水气单胞菌引起的多种中华鳖疾病,采用复乳化-溶剂挥发法制备缓释微球疫苗,通过灌胃方式免疫中华鳖（体质量150～200 g）,每只灌胃0.05 g或0.1g,微球含灭活菌约为6.75×1010/g.免疫应答反应结果显示,缓释微球疫苗体外释放可持续近40 d,血清抗体效价、白细胞吞噬率、白细胞吞噬指数及淋巴细胞转化率最高分别可达512,71.25％,1.51和77.25％.结果表明：中华鳖嗜水气单胞菌微球缓释疫苗可以达到注射灭活菌液疫苗的水平,且持续性略优于注射免疫.通过灌胃方式（0.1 g/只）、注射方式分别对中华鳖进行免疫,研究攻毒后的免疫保护率,结果显示注射免疫组和微球疫苗免疫组的免疫保护率均为85％.免疫应答实验和攻毒实验结果分别证明了中华鳖口服缓释微球疫苗免疫的持续性和有效性.

In order to control the disease of Pelodiscus sinensis caused by Aeromonas hydrophila through the way of immune prevention, sustained-release microspheres vaccine was prepared by emulsion- solvent diffusion method. The immune response was determined after intragastric administration. The range of the turtle＇s body weight was 150--200 g, the dose was 0. 1 g/individual, and 6.75 × 1010/g inacti- vated bacteria was coated in 1 g microsphere. The result of immune response showed that the duration of microspheres release was 40 d. The highest of serum antibody titer, leucocyte phagocytic rate, leucocyte phagocytic index, and lymphocyte transformation rate of the oral experimental group could reach 512, 71.25%, 1.51 and 77.25~, respectively. The immune response of the turtle via intragastric administration of sustained-release microsphere vaccine was similar to that injected with inactivated A. hydrophila, and the immune response after oral administration could persist longer than injection. The turtle was im- munized via intragastric （0.1 g/individual） or injection administration, and then challenge test was carried out. Relative protection rate of the turtle immunized by oral and injection administration were both 850//oo. The immune response experiment and challenge test could demonstrate the steadiness and validity of the sustained-release microsphere vaccine.