Increased susceptibility of white spot syndrome virus-exposed Penaeus vannamei to Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease

摘要: Abstract In this study, co-infection of white spot syndrome virus (WSSV) and AHPND-Vibrio parahaemolyticus (VpAHPND), was studied in juvenile Penaeus vannamei under the laboratory condition. Experimental shrimp were divided into 4 groups (group 1: WSSV only; group 2: VpAHPND 3: + VpAHPND; 4: not challenged), for co-infection, challenged with dual pathogens (initially exposed to subsequently VpAHPND). During experiments, we observed an increased mortality rate 3, N = 7/20 at day 2 post-infection [p.i.], N = 15/20 3 p.i.) than other (N = 1/20 p.i., N = 10/20 p.i. 2; no mortalities 1 4). Also, found obvious differences infection among groups; strong WSSV-positives detected by immunohistochemistry examination (brown coloration) qPCR assay (the copy numbers between 2.0 × 103–3.7 × 104) on termination day, but these groups. addition, there prominent histopathology hepatopancreas surviving showed typical signs AHPND hepatopancreas, sloughing hepatopancreatic tubule epithelial cells (G4) appeared normal. This study demonstrated that initially allows cause faster higher infected alone, also leads severe infection, indicating is a risk factor ponds. Therefore, farmers should pay attention management pond.