Pathological findings of Chinese sucker (Myxocyprinus asiaticus) infected with virulent Aeromonas hydrophila

A highly virulent strain of Aeromonas hydrophila (vAh) has caused the motile Aeromonas septicemia (MAS) in Chinese sucker (Myxocyprinus asiaticus). The pathology of MAS in Chinese sucker has not been studies well yet. Thus, the aim of this study was to determine histopathological and ultrastructural changes in Chinese sucker following vAh challenge. Histopathological examination revealed hemorrhage, hemolysis, endothelial cell damage, necrosis, cell vacuolation, lymphocyte infiltration and MMCs response. The ultrastructure showed severe tissue destruction, such as the malformation of glomerulus filtration device in trunk kidney, macrophages with large phagocytic vacuoles in head kidney, reticular cells and endothelial cells necrosis in spleen, the disappearing of glycogen and the degeneration of the diss space in liver. In conclusion, these results indicated that vAh infection would lead to serious pathological changes in tissues, which maybe results in death by anoxia, energy shortage and metabolic waste accumulation. Moreover, we found that MMCs in tissues might play an important role in fighting vAh infection, which would provide a new perspective for studies on the pathomechanism and enrich the histopathological data on MAS. •The pathological change of tissues in Myxocyprinus asiaticus after vAh infection was described in detail.•Some characteristic pathological changes were observed after acutely vAh infection.•The MMC response induced by acutely vAh infection was also observed.