Characterization and genome analysis of the novel phage VS1 infecting the pathogenic bacterium Vibrio splendidus of Apostichopus japonicus

Abstract Vibrio splendidus is one of the common pathogens in the ocean and infects Apostichopus japonicus, Atlantic salmon and Crassostrea gigas, leading to a variety of diseases. In this study, a virulent phage, VS1, which infects V. splendidus, was isolated from aquaculture ponds in Dalian, China. Its genome annotation and characterization were detected. The complete genome of phage VS1 consists of a linear double-stranded DNA that is 248,270 bp in length with an average G + C content of 42.5% and 144 putative protein-coding genes, and 116 genes have known functions. There are 4 tail fiber genes in the positive and negative strands of the phage VS1 genome. The domains and crystal structure of the phage VS1 tail fibers were obtained from the Protein Data Bank and SMART (http://smart.embl.de) database. The bacteriostatic effect of phage VS1 on V. splendidus culture was 93.5 times. Comparative genomic and phylogenetic analyses indicate that phage VS1 is a novel phage. This study provides the genome characterization of the novel phage VS1 that infects V. splendidus.