Morphological changes in carp epithelial cells infected with Aeromonas hydrophila

Abstract

The in vitro interaction of Aeromonas hydrophila with epithelioma papillosum cells of carp (EPC) was studied. All the virulent and type strains invaded and multiplied inside EPC cells. Morphological changes were induced by the virulent and type strains during the processes of invasion and intracellular replication. Among the virulent group, strain PPD134/ 91 required the shortest time (30 min post-infection) to induce cytopathic effects in the EPC monolayers. The EPC cells infected with PPD134/91 became retracted and condensed, lost their attachment abilities, and eventually disintegrated. Confocal microscopy revealed that tubular structures measuring 0-77 ± 0-19 μm appeared to connect the retracted EPC cells. The cytopathic effect was attributed to the growing and metabolically active bacteria. Avirulent strains such as L37 did not multiply nor induce cytopathic effects in the EPC monolayers.