Vibrio vulnificus strain:7356 Genome sequencing and assembly. Vibrio vulnificus strain:7356

Vibrio vulnificus 7356 is an isolate of biotype 3 (BT3) from an Israel patient. Three biotypes of V. vulnificus are classified according to their biological and biochemical characteristics. Biotype 1 stains are responsible for human infections, while biotype 2 strains are mainly eel pathogens. On the other hand, biotype 3 strains causing human infections have been reported only in Israel and show high clonality. Previous study indicated that all reported Vibrio species including V. vulnificus contained two circular chromosomes. Using next-generation sequencing, de novo assembly and manual inspection, then confirmed by the optical mapping and single molecular sequencing technologies, we identified the genome of the V. vulnificus biotype 3 strain 7356 contains only a single chromosome of 5,193,934 bp and four plasmids of 69.0, 49.8, 6.3, and 4.0 kb in size. This is the first case to discover a single-chromosome organization in Vibrio species. Our finding provides new insights about how biotype 3 strains evolve human pathogens and why biotype 3 strains have the geographical constrains.