Penaeus vannamei challenged with a Vibrio parahaemolyticus AHPND strain shows hepatopancreatic microbiota imbalance

White shrimp, Penaeus vannamei, farming represents one of the most important aquaculture activities in the world with a high growth rate. However, intensification processes induce negative side effects on the health of the organism, associated with a dysbiosis phenomenon. Consequently, illnesses, mainly attributable to Vibrio genus bacteria, have been reported in shrimp ponds. Studying the diversity and ecology of the associated bacteria in aquaculture systems is essential to prevent and control diseases. Therefore, the present study analyzes the bacterial load and microbial population variation in P. vannamei hepatopancreases infected with a pathogenic Vibrio parahaemolyticus strain (so-called CVP2) associated with acute hepatopancreatic necrosis disease (AHPND) under controlled conditions. The results showed an important change in the microbial community structure of the P. vannamei hepatopancreas. Furthermore, the presence of the Vibrio genus considerably increased and clearly dominated compared with the control. Dysbiosis of the hepatopancreatic microbiota and constrictions in the hepatopancreatic tubules (characteristic signs of in the early stage of AHPND) could be observed before the visible manifestation of the disease.