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

Translucent post-larvae disease (TPD) is a new emerging disease causing massive mortality in shrimp at the larval stage. A highly virulent strain of <i>Vibrio parahaemolyticus</i> is reported to be associated with TPD (<i>Vp</i> _TPD). Although few genomes from <i>Vp</i>TPD strains isolated from China have been characterized, no comprehensive genomic studies have yet to be carried out for <i>Vp</i>TPD strains isolated from samples originating outside of China. This study characterized the whole-genome sequence of <i>V. parahaemolyticus</i> strain causing TPD (<i>Vp</i> _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 <i>Vp</i> _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 <i>Vp</i> _TPD strain and diagnosis of TPD.