Identification of potential general markers of disease resistance inExopalaemon carinicaudavia three-round challenge selection with an acute hepatopancreatic necrosis disease-causing strain ofVibrio parahaemolyticus

摘要

Sixteen candidate disease-resistant parameters were selected through which to evaluate the acute hepatopancreatic necrosis disease (AHPND)-resistant capability ofExopalaemon carinicaudaafter three generations of selection for AHPND-causing strain ofVibrio parahaemolyticus(VPAHPND) resistance in our previous study. However, these parameters required further verification. In this study, another AHPND-resistantE. carinicaudaseries was obtained through a short-term selection procedure, consisting of three virulent challenge rounds of selection (about three-week interval for each challenge) with VP(AHPND)infection. After this selection, the survival rate at 144 hr post infection (hpi) increased from 23.33% to 37.78% and the observed 48-hr LD(50)of VP(AHPND)to shrimp increased from 10(5.5) cfu/ml to 10(6.5) cfu/ml. Then, the immune response of this AHPND-resistantE. carinicaudawas studied using the 16 candidate AHPND-resistant parameters selected for in our previous study. The improved VP(AHPND)clearance rate in hpi, increased total haemocyte counts, haemocyanin concentration, alkaline phosphatase activity and expressions of six immune-related genes (Tollip and ALF in haemocytes and hepatopancreas; lysozyme, crustin and cathepsin B in hepatopancreas; and LGBP in haemocytes) at 24 hpi after the three-round challenge selection suggest that these immune parameters may be reliable markers for the evaluation of the physiological status and potential AHPND-resistant phenotypes inE. carinicauda.