Abstract. The increasing frequency of isolation of methicillin-resistant Staphylococcus aureus (MRSA) limits the chances of effective antibacterial therapy of staphylococcal diseases and results in development of persistent infection such as bacteremia and osteomyelitis. The aim of this study was to identify features of the MRSAST239 0943-1505-2016 (SA943) genome, that contribute to the formation of both acute and chronic musculoskeletal infections. The analysis was performed using comparative genomics data of the dominant epidemic S. aureus lineages namely ST1, ST8, ST30, ST36, ST239. SA943 genome encodes proteins that provide resistance to the host immune system, suppress immunological memory and form biofilms. The molecular mechanisms of adaptation responsible for development of persistent infection were as follows: amino acid substitution in PBP2 and PBP2a, providing resistance to ceftaroline; loss of a large part of prophage DNA and restoration of nucleotide sequence of beta-hemolysin, that greatly facilitates escape of phagocytosed bacteria from phagosome and formation of biofilms; dysfunction of the AgrA system due to the presence of psm-mec and several amino acid substitutions in the AgrC; partial deletion of nucleotide sequence in genomic island vSAβ resulting in the loss of two proteases of Spl - operon; deletion of SD repeats in SdrE amino acid sequence.