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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
14:04

Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria

Published on: May 8, 2013

Factors influencing methicillin resistance in staphylococci

Brigitte Berger-Bächi1, Susanne Rohrer

  • 1Institute of Medical Microbiology, University of Zürich, Gloriastrasse 32, PO Box, 8028 Zürich, Switzerland. bberger@immv.unizh.ch

Archives of Microbiology
|August 22, 2002
PubMed

Insights

Methicillin resistance in staphylococci stems from acquired penicillin-binding protein PBP2a, encoded by mecA. Resistance levels in MRSA are influenced by PBP2a production and chromosomal factors, varying widely among strains.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Genetics

Background:

  • Methicillin resistance in staphylococci is a significant clinical concern.
  • The mecA gene encodes an altered penicillin-binding protein, PBP2a, responsible for intrinsic resistance to beta-lactam antibiotics.
  • Resistance levels in MRSA are variable and influenced by multiple factors.

Purpose of the Study:

  • To investigate the mechanisms underlying varying levels of methicillin resistance in Staphylococcus aureus (MRSA).
  • To explore the role of chromosomal factors in modulating PBP2a production and resistance expression.
  • To understand the heterogeneous expression of resistance in MRSA populations.

Main Methods:

  • Analysis of mecA gene presence and PBP2a expression in clinical MRSA isolates.
  • Investigation of genetic backgrounds and chromosomal factors associated with different resistance phenotypes.
  • Assessment of cell-wall precursor synthesis and related gene functions in relation to resistance levels.

Main Results:

  • MRSA resistance levels are determined by PBP2a production efficiency, modulated by chromosomal elements.
  • Genetic background significantly impacts the range of resistance, from susceptible to highly resistant phenotypes.
  • Heterogeneous resistance expression in MRSA is linked to subpopulations exhibiting higher resistance upon methicillin challenge.

Conclusions:

  • PBP2a production and chromosomal factors are key determinants of MRSA resistance levels.
  • Understanding the interplay between mecA and host genetics is crucial for predicting and managing MRSA infections.
  • Further research is needed to elucidate the specific roles of cell-wall synthesis and regulatory genes in clinical MRSA isolates.

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