壳聚糖硫酸酯提高异育银鲫抗嗜水气单胞菌感染的研究  

On enhancement of resistance of Crucian carp Carasius auratus gibelis against Aeromonas hydrophila after feeding chitosan sulfate

作　　者：周帅[1] 周常[1,2] 房文红[1] 

机构地区：[1]中国水产科学研究院东海水产研究所,农业部海洋与河口渔业重点开放实验室,上海200090 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《海洋渔业》2010年第4期427-434,共8页Marine Fisheries

基　　金：上海市科教兴农重点攻关项目,沪农科攻字(2005)第10-5号

摘　　要：对异育银鲫连续7 d分别投喂添加壳聚糖硫酸酯0.1%、0.2%和0.4%的配合饲料,然后用嗜水气单胞菌进行攻毒,以检测壳聚糖硫酸酯对病原菌的抗感染能力。实验结果显示,与对照组相比,试验组呈现出不同程度的免疫保护作用,其中以壳聚糖硫酸酯添加量为0.2%试验组的免疫保护效果最明显,异育银鲫的成活率达到46.67%;添加量为0.1%和0.4%试验组的成活率分别为23.33%和30.0%,而攻毒对照组100%死亡。然后将添加0.2%壳聚糖硫酸酯的饲料用同样的方式投喂异育银鲫,检测其血清和肝组织中的酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、溶菌酶(LSZ)和超氧化物歧化酶(SOD)活性,并分析肝组织中各酶的基因表达量。结果显示,异育银鲫血清和肝组织中的ACP、AKP、LSZ和SOD活性均得到显著提高,且四种酶的活性均呈现随时间延长而先升高后降低的趋势,并于第三天达到峰值,血清和肝组织中ACP活性比对照组分别提高了54.62%和26.58%、AKP提高了37.61%和25.88%、LSZ提高了13.42%和35.43%、SOD提高了18.59%和54.62%;试验组异育银鲫肝组织中ACP、AKP和LSZ的mRNA表达量均得到显著提高,并随时间推移呈现出先升高后降低的趋势,于72 h到达峰值,而SOD的mRNA表达量与对照组相比没有显著变化。综合以上结果,壳聚糖硫酸酯能够显著提高异育银鲫非特异性免疫水平,增强抗嗜水气单胞菌的能力,表明壳聚糖硫酸酯可作为免疫增强剂用于鱼类疾病的预防与治疗。Crucian carp Carasius auratus gibelis were continuously fed with chitosan sulfate for a week and then challenged with Aeromonas hydrophila.Results showed that the survival rate of Crucian carp fed with 0.1%,0.2% and 0.4% chitosan sulfate were significantly higher than the control and increased by 23.33%,46.67% and 30%,respectively.Subsequently,in order to further evaluate the possible function of chitosan sulfate as a immune potentiator on Crucian carp,the main immune parameters of the fish fed with 0.2% chitosan sulfate were determined,including acid phosphates（ACP）,Alkaline phosphatase（AKP）,lysozyme（LSZ） and superoxide dismutase（SOD）.After that,the mRNA expression levels of those enzymes were analyzed with semiquantitative RT-PCR.It could be seen from the time-course experiment results that the activities of ACP,AKP,LSZ and SOD increased at first,reached the peak at the third day and then decreased gradually.The ACP,AKP,LSZ and SOD activity at the top point increased respectively by 54.62%,37.61%,13.42%,and 18.59% in plasma,and 26.58%,25.88%,35.43% and 54.62% in liver.In addition,the RT-PCR results demonstrated that the mRNA expression levels of ACP,AKP,LSZ and SOD were in agreement with the trends of the four enzyme activity,except mRNA expression of SOD,which showed no significant difference compared to the control.The present work suggested that the application of chitosan sulfate as immunostimulant would be effective against fish bacterial infection and could be recommended to control aquatic diseases.

关 键 词：壳聚糖硫酸酯 嗜水气单胞菌 免疫保护率 非特异免疫因子 MRNA 

分 类 号：S941.42[农业科学—水产养殖]