Plasmids of Clostridioides difficile

•Plasmids likely occur in >10% of strains of C. difficile.•Plasmids can affect traits such as antimicrobial resistance, but for most there is no demonstrated consequence of carriage.•The majority of C. difficile plasmids are <10 kb, but putative plasmids of ∼300 kb are described.•Though direct evidence for conjugative transfer of these plasmids is lacking, there is indirect evidence for inter-species transfer of C. difficile plasmids.