Diverse dif module content and configurations in the r3-T5 group of Rep₃/OrfX plasmids from Acinetobacter species reveal extensive dif module shuffling

The plasmids that are associated with Acinetobacter isolates appear to be restricted to this genus. However, the unique properties of the many and various plasmid types found in Acinetobacter species have received little attention relative to the plasmids of other gram-negative pathogens. In addition, the novel dif module mobile element system, also found uniquely in Acinetobacter species, was recently shown to be naturally associated with a specific type of Acinetobacter plasmid. To investigate the dynamics of dif module movement, here, the properties and configurations of one group of plasmids with identical or closely related backbones that carry different dif modules or the same modules in different configurations have been examined. This will increase understanding of the global distribution and diversity of plasmids that carry dif modules, as well as provide insight into the way dif modules relocate.