Isolation of bacterial vesicles and characterisation of their genetic cargo

Abstract

Extracellular vesicles are small round bodies secreted from the membranes of most living cells, including bacteria. The bacterial vesicles contain many of the same components as the mother bacteria and play numerous roles in host–pathogen relationships, as well as in bacterial communication. For instance, vesicles from certain species can serve as an offense to kill other bacterial strains, while others can transfer helpful antibiotic resistance genes. For us, the most common application for vesicles is as vaccine candidates against their parent strains, and in this context, it is essential with thorough characterization of the medicine in question, including any potential genetic cargo that may be transmitted to present bacteria, or to cells of the host. The genetic cargo of bacterial vesicles is therefore the main focus of this thesis; by comparing full DNA and RNA sequencing data with protein abundances, light is shed on the proportional composition of vesicles compared to their parent bacteria. Additionally, the work provides a comparison between certain methods for acquiring sufficient vesicle-borne genetic material, leading to decisive information for future experiments.