为了解大黄鱼在抗溶藻弧菌感染时免疫功能的变化规律,将160尾健康大黄鱼分为感染组和对照组,通过腹腔分别注射0.2mL浓度为2×107CFU.mL-1的溶藻弧菌和灭菌生理盐水,在注射0,1,3,7,11,15,19d后从两组各取6尾大黄鱼,尾静脉取血,进行外周血的血相、NBT阳性细胞数、血清抗菌活力、抗体效价等免疫学指标的测定。结果显示:在人工感染的初期,感染组大黄鱼外周血的红细胞、白细胞、淋巴细胞和NBT阳性细胞的数量及血清抗菌活力等指标均较对照组有显著提高;在注射后1d外周血粒细胞的数量显著低于对照组;抗体效价在7d开始增加,15d达到峰值,且用间接ELISA和试管凝集两种方法所得结果具有非常高的同步性。结果表明:在感染溶藻弧菌后,大黄鱼能通过红细胞和白细胞增殖、释放抗菌物质、产生特异性抗体等方式提高其对溶藻弧菌的免疫力;在感染的早期阶段非特异性免疫因子起主要作用,在感染后期阶段特异性免疫因子起重要作用;NBT阳性细胞数可以作为细菌感染的指标。To investigate the effect of experimental infection with Vibrio alginolyticus on immune parameters of Pseudosciaena crocea,one hundred and sixty healthy fish were categorized into infected and control groups.Each fish in infected group was injected intraperitoneally with 0.2 mL of bacteria suspension with a concentration of 2×107 CFU·mL-1,while each fish in control group was injected i.p.with 0.2 mL of sterile saline solution. P.crocea in both groups were sacrificed at 0,1,3,7,11,15 and 19 d post-injection to evaluate immune parameters such as haematocyte counting,NBT-positive cells,serum antibacterial activity,and serum antibody titer.The results showed that: experimental infection with V.alginolyticus would increase the numbers of erythrocytes,leucocytes,lymphocytes in peripheral blood as well as peripheral serum antibacterial activity and antibody titer of P.crocea,and reduce peripheral blood granulocytes number significantly,in comparison with those in control group.These results suggested that after infected by V.alginolyticus,P.crocea would enhance its resistance to the invaded bacteria by means such as erythrocyte and leucocyte proliferating,antibacterial substance excreting,antibodies synthesizing;non-specific immune factors including antibacterial substance in peripheral blood played an important role at the initial stages of infection,and then specific immune factors such as antibody played an important role at the later stages;the number of NBT positive cell was a good indicator of bacterial infection.国家“八六三”高新技术发展计划(2002AA639600);; 福建省自然科学基金项目(B0410022);; 福建省青年创新基金项目(2002J037
