Biology of the staphylococcal conjugative multiresistance plasmid pSK41

Plasmid pSK41 is a large, low-copy-number, conjugative plasmid from Staphylococcus aureus that is representative of a family of staphylococcal plasmids that confer multiple resistances to a wide range of antimicrobial agents. The plasmid consists of a conserved plasmid backbone containing the genes for plasmid housekeeping functions, which is punctuated by copies of IS257 that flank a Tn4001-hybrid structure and cointegrated plasmids that harbour resistance genes. This review summarises the current understanding of the biology of pSK41, focussing on the systems responsible for its replication, maintenance and transmission, and their regulation.

► pSK41 is the prototypical conjugative multiresistance plasmid from Staphylococcus aureus.
► pSK41-like plasmids have played an important role in the development of antimicrobial resistance in staphylococci.
► Current understanding of pSK41 replication, maintenance and transmission is reviewed.