Popis: |
Red-spotted grouper nervous necrosis virus (RGNNV) is a highly infectious, explosive, and lethal virus that mainly infects marine fish larvae. Currently, there is no effective method to mitigate the impact of RGNNV on aquaculture production. Previous studies have shown that yolk immunoglobulin (IgY) can neutralize RGNNV in grouper fin-1 (GF-1) cells. In this study, RGNNV propagated in GF-1 cells was harvested and purified successfully. The purified RGNNV was used as an immunogen to immunize laying hens. Water-soluble fractions were separated from egg yolk, and IgY was harvested using a two-step precipitation method with saturated ammonium sulfate salt. In vitro analysis showed that the purified IgY could neutralize RGNNV. An in vivo protection assay with groupers revealed that fish fed with 10% lyophilized egg yolk powder from immunized hens were significantly protected during RGNNV challenge. The relative protection rates of groupers under treatment after RGNNV infection and continuous feeding during RGNNV infection were 68% and 70%, respectively, when fed with 10% specific egg yolk powder. This is the first study to validate that anti-RGNNV IgY can effectively protect groupers from RGNNV infection, laying a foundation for the development of anti-RGNNV products. |