3种美人鱼发光杆菌疫苗对卵形鲳鲹的免疫效果

The Immune Efficiency of Three Vaccines of Photobacterium damselae subsp.piscicida to Trachinotus ovatus

用美人鱼发光杆菌Photobacterium damselae subsp.piscicida制备外膜蛋白(OMP)、脂多糖(LPS)及甲醛灭活全菌(FKC)3种疫苗,分别腹腔注射卵形鲳鲹Trachinotus ovatus,在免疫后第7、14、21、28天进行尾静脉采血,检测试验鱼的白细胞吞噬活性、溶菌酶活力以及血清凝集抗体效价等免疫指标.与对照组相比,OMP、LPS和FKC均能显著提高所测的免疫指标(P<0.05),白细胞吞噬百分比、吞噬指数和血清溶菌酶活力在免疫第14～21天内,保持较高的水平,而血清抗体滴度则在免疫第14天后维持在较高的水平.免疫第28天后,测得LPS或OMP免疫组的鱼体增质量率明显高于FKC免疫组(P<0.05),同时进行人工感染,LPS、OMP和FKC免疫组的相对保护率分别为66.7%、60.0%和38.8%.说明注射美人鱼发光杆菌的LPS或OMP疫苗能给卵形鲳鲹提供良好的免疫保护效果.

The vaccines of formalin-killed bacterial cells（FKC）,outer membrane protein（OMP） and lipopolysaccharide（LPS） were prepared from Photobacterium damselae subsp.piscicida and were immunized respectively to golden pompano,Trachinotus ovatus,via intraperitoneal injection.The phagocytes activities,lysozyme activities and agglutinating antibody activities were assayed on 7,14,21,and 28 days after immunization.The fish immunized with LPS,OMP and FKC showed significantly higher phagocytes activities,lysozyme activities and agglutinating antibody activities than the control group（P0.05）.The phagocytic percentage（PP）,phagocytic index（PI） and lysozyme activities were at higher level between 14 and 21 days whereas the agglutinating antibody titers were the highest after 14 days of injection.The mass gain rate（MGA） in fish immunized with LPS or OMP were significantly higher than those of FKC（P0.05） after 28 days of immunization.The study showed that relative percent survival rates of lipopolysaccharide,outer membrane protein and formalin-killed bacterial cells were 66.7%,60.0% and 38.8%,respectively.It appeared that LPS or OMP of Photobacterium damselae subsp.piscicida could provide higher immune efficiency.