Bacterial extracellular vesicles as carriers of genetic and regulatory messages

Although bacterial extracellular vesicles (BEVs) are increasingly recognized as mediators of communication, the contribution of their nucleic acid cargo remains poorly understood. Providing an overview of BEV-nucleic acid content and their roles, this review first examines their true significance. In particular, it highlights why they should not be treated as bulk cargo, given that DNA and RNA contents exhibit various sub-vesicular localizations that may define their ecological roles. We propose that this heterogeneity allows viewing BEVs as distinct subpopulations. Furthermore, recent studies increasingly propose the involvement of DNA associated with BEVs in horizontal gene transfer between bacteria and that of vesicular small RNA (sRNA) during host-bacteria interactions. Overall, this review offers insights into considering BEVs in an ecological context based on notable recent studies.