Genomic characterization of Vibrio parahaemolyticus strain (AG1) causing translucent post-larvae disease in Penaeus...

Translucent post-larvae disease (TPD) is a new emerging disease causing massive mortality in shrimp at the larval stage. A highly virulent strain of Vibrio parahaemolyticus is reported to be associated with TPD (Vp _TPD). Although few genomes from VpTPD strains isolated from China have been characterized, no comprehensive genomic studies have yet to be carried out for VpTPD strains isolated from samples originating outside of China. This study characterized the whole-genome sequence of V. parahaemolyticus strain causing TPD (Vp _TPD). The whole-genome sequence of VpTPD was ~5.5 Mb, consisting of two chromosomes and three plasmids. One of the three plasmids encodes three (VHVP) proteins, causing TPD in shrimp. Genomic characterization revealed that Vibrio High Virulent Protein(VHVP) is a Tc-like toxin complex. Laboratory bioassays conducted using Vp _TPD revealed that bacterial isolate used in this study causes mortality at the late stage of post-larvae (PL10-PL20). The findings broaden our understanding of the pathogenicity of the Vp _TPD strain and diagnosis of TPD.