Skip to main content

Factors influencing methicillin resistance in staphylococci

Abstract.

Methicillin resistance in staphylococci is due to an acquired penicillin-binding protein, PBP2′ (PBP2a). This additional PBP, encoded by mecA, confers an intrinsic resistance to all β-lactams and their derivatives. Resistance levels in methicillin-resistant Staphylococcus aureus (MRSA) depend on efficient PBP2′ production and are modulated by chromosomal factors. Depending on the genetic background of the strain that acquired mecA, resistance levels range from phenotypically susceptible to highly resistant. Characteristic for most MRSA is the heterogeneous expression of resistance, which is due to the segregation of a more highly resistant subpopulation upon challenge with methicillin. Maximal expression of resistance by PBP2′ requires the efficient and correct synthesis of the peptidoglycan precursor. Genes involved in cell-wall precursor formation and turnover, regulation, transport, and signal transduction may determine the level of resistance that is expressed. At this stage, however, there is no information available on the functionality or efficacy of such factors in clinical isolates in relation to methicillin resistance levels.

This is a preview of subscription content, access via your institution.

Author information

Affiliations

Authors

Additional information

Electronic Publication

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Berger-Bächi, B., Rohrer, S. Factors influencing methicillin resistance in staphylococci. Arch Microbiol 178, 165–171 (2002). https://doi.org/10.1007/s00203-002-0436-0

Download citation

  • aux fem Staphylococcus aureus mecA mecR1 mecI Methicillin resistance Penicillinase Regulation SCCmec