Genome analysis of a unique strain of Vibrio cholerae O1 carrying the theird replicon

点击翻译按钮获取中文摘要

In this study, we found three isolates TSY216, TSY241, and TSY421, of Vibrio cholerae O1 carrying a 0.9 Mb replicon (Ch3) in addition to the two circular chromosomes, 1 (Ch1; 3.0 Mb) and 2 (Ch2; 1.0 Mb). The genome of TSY216 carrying the Ch3 was compared with that of epidemic V. cholerae O1. The chromosomes 1 and 2 were very similar among TSY216 and other epidemic strains. However, the Ch3 did not share any conserved region with Ch1 and Ch2. Ch3 was found to encode 1,031 ORFs and 66 genes encoding tRNAs for 20 amino acids. The origin and function of Ch3 remain unidentifiable. The acquisition of a large-scale gene set of the third replicon may provide an opportunity to result in a new emerging form of V. cholerae O1.