壳聚糖硫酸酯提高凡纳滨对虾抗白斑综合征病毒感染力的研究

Study on enhancement of Litopenaeus vannamei relied upon oral administration of chitosan sulfate to resist the infection of white spot syndrome virus

论述如下一项研究,采用壳聚糖硫酸酯添加到饲料中投喂凡纳滨对虾,4周后检测对虾血清酚氧化酶、超氧化物歧化酶和溶菌酶活性;同时进行白斑综合征病毒(WSSV)的肌肉注射感染实验,以检测壳聚糖硫酸酯对病毒的抗感染能力。实验结果显示,饲料中壳聚糖硫酸酯添加量为0.15‰和0.50‰,能显著提高凡纳滨对虾血清酚氧化酶活性;添加量为0.15‰时,能显著提高对虾血清超氧化物歧化酶活性,但添加量继续增大时反而下降;在低添加量时,对虾血清溶菌酶活性与对照组相近,添加量为0.15‰和0.50‰时,对虾血清溶菌酶活性随添加量增大而升高。凡纳滨对虾摄食添加壳聚糖硫酸酯饲料4周后,经注射WSSV攻毒感染,壳聚糖硫酸酯添加量为0.04‰、0.15‰和0.50‰试验组,对虾比成活率分别为39.3%、42.9%和53.6%,而未摄食壳聚糖硫酸酯的对照组成活率仅为17.9%。结果表明,摄食壳聚糖硫酸酯可以明显提高对虾抵御WSSV感染的能力。

Present paper deals with an experiment as follows.Litopenaeus vannamei were fed on the diet with chitosan sulfate for a period of 4 weeks and then determined the activities of phenoloxidase（PO）,superoxide dismutase（SOD） and lysozyme in serum,simultaneusly challenged with inframascular injection of white spot syndrome virus to determine their abilities on resistant infection.Results revealed that when shrimps fed on diet with 0.15‰ and 0.50‰ chitosan sulfate,the phenoloxidase activies were significantly higher than the control,while the supplement of chitosan sulfate was 0.15‰,the superoxide dismutase activities were obviously higher than the control,however the supplement with 0.50‰ chitosan sulfate would be inhibited the activity of superoxide dismutase.The lysozyme activity of shrimps fed on diet with 0.04‰ chitosan sulfate was close to that of the control,while the lysozyme activity would be increased along with the supplement with 0.15‰ and 0.50‰ chitosan sulfate.After 4 weeks of feeding experiment,the shrimps were challenged with WSSV,the survival rate of shrimps fed on diets with 0.04‰,0.15‰ and 0.50‰ chitosan sulfate were 39.3%,42.9% and 53.6%,respectively,while the survival rate of the control was 17.95% only.The present work revealed that the application of chitosan sulfate immunostimulant would be effective against shrimp viral pathogenesis and it could be recommended for shrimp culture.