The Complete Genome Sequencing And Comparative Genomics Analysis Of Vibrio Choleraee CHN108B

Vibrio cholerae is a causative agene of the serious human intestinal pathogen disease cholera. To Oct. 1st 2014, the complete genome sequences of nine strains of Vibrio cholerae strains have been determined and available in the public databases,of which only one V.cholerae LMA398404 strains was isolated from the environment.In this study, we determined the complete genome sequence of the V. choleraee CHN108 B strain,which was isolated from the Yangtze River estuary, China by Professor Lanming Chen’s laboratory,using the high throughput Roche/454 GS FLX titanium system.The V. choleraea CHN108 B was assembled into two circular chromosomes with, a total size of 4168545 bp.The larger chromosomes I is 3083301 bp with an average G+C content of 47.8% and contains 2701 annotated proteins, while the smaller chromosome II is 1085244 bp,with an average G+C content of 46.8% and 990 annotated proteins. Moreover, CHN108 B genome encodes 22 r RNAs(all on chromosome I) and 76 t RNAs(73 on chromosome I and 3 in chromosome II). The strains unique genes in CHN108 B is the most(281). CHN108 B contains 2 prophages clusters and an insertion sequence IS1358. Moreover, the smaller chromosome contains a 136 kb(Chr2: 1020412-72140bp) super-intergon(SI),that carries a new gene encoding a streptogramin A acetyltransferase(Vat D), which was absent from the other nine V.cholerae strains of SI, while the bigger chromosome harbors a 73269 bp integration conjunct elements(ICE)(338087-411356bp). Moreover, CHN108 B genome also encodes putative virulence-associated factors enterotoxigenic hemolysin, intact flagella and mannose sensitive hemagglutinin(MSHA), as well as rifamipin and tetracycline resistance genes(rps L,tet34,tet35). In addition, CHN108 B genome has notable different metabolic pathways from the other genomes,such as the fructose and mannose metabolism, ascorbate and aldarate metabolism, amino sugar and nucleotide sugar metabolism, glycine, serine and threonine metabolism and streptomycin biosynthesis. CHN108 B phylogenetically distant from the other Vibrio cholerae strains by whole genome core gene analysis. The results in this study will facilitate better understanding of the evolution process of V. cholerae genomes.