New publication in Current Biology: Plasmids drive genome evolution in intracellular bacteria


In this study, a team around Stephan Köstlbacher and Matthias Horn have unvestigated the plasmid inventory of an entire bacterial phylum, the Chlamydiae, a diverse group of ubiquitous and strictly intracellular pathogens and symbionts. Their analysis revealed how plasmids shaped the genomes of these host-associated microbes. They show that plasmid-derived genes were likely involved in the transition of chlamydiae from symbionts in protists to pathogens of humans and animals. The authors propose a scenario in which host-plasmid coevolution can be traced back over a period of 1 billion years.