Exception to the Rule: Genomic Characterization of Naturally Occurring Unusual Strains with a Single Chromosome.

The genetic make-up of most bacteria is encoded in a single chromosome while about 10% have more than one chromosome. Among these, , with two chromosomes, has served as a model system to study various aspects of chromosome maintenance, mainly replication, and faithful partitioning of multipartite genomes. Here, we describe the genomic characterization of strains that are an exception to the two chromosome rules: naturally occurring single-chromosome .

Whole genome sequencing and comparative genomic analyses of two Vibrio cholerae O139 Bengal-specific Podoviruses to other N4-like phages reveal extensive genetic diversity.

Background: Vibrio cholerae O139 Bengal is the only serogroup other than O1 implicated in cholera epidemics. We describe the isolation and characterization of an O139 serogroup-specific phage, vB_VchP_VchO139-I (ϕVchO139-I) that has similar host range and virion morphology as phage vB_VchP_JA1 (ϕJA1) described previously. We aimed at a complete molecular characterization of both phages and elucidation of their genetic and structural differences and assessment of their genetic relatedness to the N4-like phage group.