Elevated linezolid resistance in clinical cfr-positive Staphylococcus aureus isolates is associated with co-occurring mutations in ribosomal protein L3

Antimicrob Agents Chemother. 2010 Dec;54(12):5352-5. doi: 10.1128/AAC.00714-10. Epub 2010 Sep 13.

Abstract

Resistance to linezolid (LZD) occurs through mutations in 23S rRNA and ribosomal proteins L3 and L4 or through methylation of 23S rRNA by Cfr. Here we report novel L3 mutations, ΔSer145/His146Tyr and ΔMet169-Gly174, co-occurring with cfr in LZD-resistant Staphylococcus aureus isolates recovered from a hospital outbreak in Madrid, Spain. LZD MIC values (16, 32, or 64 μg/ml) correlated with the presence and severity of the L3 mutation. All isolates had TR-700 (torezolid) MIC values of ≤ 2 μg/ml.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides / pharmacology*
  • Anti-Infective Agents / pharmacology*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Drug Resistance, Bacterial / genetics*
  • Linezolid
  • Methyltransferases / chemistry
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Microbial Sensitivity Tests
  • Mutation
  • Oxazolidinones / pharmacology*
  • Ribosomal Protein L3
  • Ribosomal Proteins / chemistry
  • Ribosomal Proteins / genetics*
  • Ribosomal Proteins / metabolism
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / enzymology
  • Staphylococcus aureus / genetics

Substances

  • Acetamides
  • Anti-Infective Agents
  • Bacterial Proteins
  • Oxazolidinones
  • Ribosomal Protein L3
  • Ribosomal Proteins
  • Methyltransferases
  • Linezolid