Effects of Vibrio parahaemolyticus isolated from giant prawn on hepatopancreas cells

Abstract Macrobrachium rosenbergii is farmed worldwide. However, large-scale farming emerges to disease outbreaks. In this study, the V. parahaemolyticus strain KAK20 was isolated from M. rosenbergii with an abnormal hepatopancreas. The isolated bacteria were identified by 16S rRNA sequencing. PCR showed the presence of the ToxR virulent gene. The pathogenicity of V. parahaemolyticus strain KAK20 was studied using hepatopancreas cells isolated from healthy prawns. Results demonstrated that a multiplicity of infection (MOI) of 1 and 2 caused the highest cell death ratio, approximately 70% within two hour infection. Higher MOI values increased membrane damage with lower intracellular bacterial counts. Upregulation of Hsp70 and ProPO in hepatopancreas cells at 2-hour-post-infection revealed an activated immune response. These results showed that V. parahaemolyticus strain KAK20 is able to infect hepatopancreas cells at MOI 0.1 and trigger antibacterial immune. Understanding the pathogenic characteristics of this strain will contribute to developing disease prevention strategies in M. rosenbergii aquaculture.