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

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.