鲖爱德华菌口服疫苗对斑点鲖的免疫效果

为评价鲖爱德华菌口服微球疫苗对斑点鲖的免疫效果,实验以天然高分子聚合物海藻酸钠和鲖爱德华菌灭活疫苗为材料,制备鲖爱德华菌口服微球疫苗。将实验动物随机分为鲖爱德华菌微球疫苗组、鲖爱德华菌灭活疫苗组、空微球组和对照组,以拌料口服方式进行免疫,通过检测血清中溶菌酶活力、总超氧化物歧化酶(T-SOD)活力、补体替代途径(ACH50)活性等非特异性免疫指标,抗体效价以及相对免疫保护率评价疫苗免疫效果,采用荧光定量PCR检测口服疫苗对斑点鲖免疫相关基因表达量的影响。结果显示,鲖爱德华菌口服微球疫苗能够较长时间增强斑点鲖非特异性免疫功能;血清凝集效价于第5周达到峰值,为1∶16,免疫后第7周仍可检测到特异性抗体;口服鲖爱德华菌微球疫苗的斑点鲖获得的抗鲖爱德华菌相对免疫保护率为60.7%,远高于灭活疫苗组(14.3%)及空微球组(10.7%);荧光定量分析结果显示,攻毒后48 h相比攻毒前各免疫基因表达量均有上调,鲖爱德华菌微球疫苗对受免鱼肾脏、脾脏中免疫基因的表达影响尤为明显。结果表明,鲖爱德华菌口服微球疫苗能增强斑点鲖非特异性免疫功能,对鲖爱德华菌病起到一定的预防作用。

The immune effect of an oral microspheres vaccine against Edwardsiella ictaluri on channel catfish (Ictalurus punctatus)

To evaluate the immune effect of an oral vaccine of Edwardsiella ictaluri in Channel catfish, Edwardsiella ictaluri were killed by formalin and sodium alginate were used to prepare the oral microsphere vaccine. The experimental animals were randomly divided into four groups, including Edwardsiella ictaluri oral microspheres vaccine group, formalin inactivated vaccine group, microspheres without antigen group and control group. After oral immunization, the effect of the vaccine was evaluated by serum non-specific immune parameters, antibody titers and relative percent survival detection. Results showed the serum lysozyme activity, total superoxide disumutase activity (T-SOD) and alternative pathway complement activity (ACH50) significantly increased in vaccinated channel catfish, analysising the influence of the relativity gene transcripyion of the Ictucurus punctatus fed these oral vaccine respectively by real-time PCR.The results showed that the Ictucurus punctatus fed the Edwardsiella ictaluri oral microsphere vaccine can acquire longer time of nonspecific imumunity. The serum agglutination titers peaked to 1: 16 at 5th week. The specific antibodies could although be detected at 7th week. The relative percent survival to Channel Catfish was 60.7%, far higher than formalin inactivated vaccine group (14.3%) and microspheres without antigen group (10.7%). Analysising the results of real-time PCR, it is found that in the Edwardsiella ictaluri oral microspheres vaccine group, the expression of imumunity genes had increased more notably than other groups during the 48 hours after injection ,especially in the kidney and spleen. In conclusion, the oral microspheres vaccine of Yersinia ruckeri was able to enhance the non-specific immune function and good for preventing Yersinia ruckeri disease.