家蝇抗菌肽对凡纳滨对虾抗白斑综合征病毒能力的影响

Effects of antibacterial peptides of Musca domestica on anti-white spot syndrome virus capacity in Litopenaeus vannamei

为研究饲料中添加家蝇抗菌肽对凡纳滨对虾抗白斑综合征病毒能力的影响,在基础饲料中分别添加家蝇抗菌肽提取物0、1、2、3、4、5 g/kg,配制6种试验饲料.选取960尾健康、初始体均重为0.86（±0.01）g的凡纳滨对虾,分为6组,饲养8周后进行攻毒试验.结果显示,当抗菌肽提取物添加量为3 g/kg时,72 h内的累计死亡率与对照组相比显著降低.血细胞数量和吞噬率均以3 g/kg组最高,显著高于对照组、1、5g/kg组.当抗菌肽提取物添加量为2～3 g/kg时,对虾血清过氧化物酶（POD）、碱性磷酸酶（AKP）、溶菌酶（LZM）活性和总抗氧化能力（T-AOC）均维持在一个较高的水平,且显著高于对照组;4 g/kg组超氧化物歧化酶（SOD）活性与对照组相比显著升高,肝胰腺AKP活性、T-AOC水平均以4 g/kg组最高,显著高于对照组;3g/kg组LZM活性显著高于对照组、1、4、5 g/kg组.结果表明,饲料中添加适量的家蝇抗菌肽可以提高凡纳滨对虾的免疫力和抗白斑综合征病毒的能力.

To evaluate the effects of antibacterial peptides of Musca domestica （ABPs-MD） on the resistance ability to white spot syndrome virus （WSSV） in Litopenaeus vannamei, six experimental diets were prepared by supplementing into the basal diet with 0, 1, 2, 3, 4 and 5 g/kg ABPs-MD, respectively. 960 juvenile L. vannamei with an initial average weight of 0.86 （±0.01） g were randomly divided to 6 groups. After 8-week feeding trial, shrimps were injected with WSSV. The results showed that supplementing ABPs-MD at 3 g/kg significantly reduced the cumulative mortality. The highest number of haemocytes and hemolymph phagotrophy rate were both obtained in the shrimps fed the diet with ABPs-MD at 3 g/kg, significantly higher than those in the control, 1 g/kg and 5 g/kg groups. When ABPs-MD was supplemented at 2-3 g/kg, the shrimps showed a higher level in activities of POD, AKP, LZM and T-AOC in serum, significantly higher than those in the control group. The highest activities of SOD in serum, AKP and T-AOC in hepatopancreas were all obtained in the shrimps fed the diet with ABPs-MD at 4 g/kg, significantly higher than those in the control group. The highest activity of LZM was obtained in the shrimps fed the diet with ABPs-MD at 3 g/kg, significantly higher than that in the control, 1, 4 and 5 g/kg groups. The results suggested that the dietary supplementation of antibacterial peptides could improve the non-specific immunity and disease resistance to WSSV in L.vannamei.