Identification and characterization of the multidrug resistance gene cfr in a Panton-Valentine leukocidin-positive sequence type 8 methicillin-resistant Staphylococcus aureus IVa (USA300) isolate

Antimicrob Agents Chemother. 2010 Dec;54(12):4978-84. doi: 10.1128/AAC.01113-10. Epub 2010 Oct 4.

Abstract

The staphylococcal cfr gene mediates resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins, and streptogramin A, a phenotype that has been termed PhLOPS(A). The cfr gene has mainly been associated with coagulase-negative staphylococcal isolates from animals, and only a few cfr-positive methicillin-resistant Staphylococcus aureus (MRSA) isolates have been described so far. This study reports the first description of a cfr-positive MRSA isolate (M05/0060) belonging to the pandemic Panton-Valentine leukocidin (PVL)-positive sequence type 8 MRSA IVa/USA300 (ST8-MRSA-IVa/USA300) clone. The cfr gene was detected in M05/0060 using a DNA microarray which was used to screen PVL-positive MRSA isolates for the presence of virulence genes, typing markers, and antimicrobial resistance genes. Antimicrobial susceptibility testing revealed that M05/0060 exhibited the cfr-associated resistance phenotype. Molecular analysis identified the presence of cfr and a second phenicol resistance gene, fexA, on a novel 45-kb conjugative plasmid, which was designated pSCFS7. Within pSCFS7, a DNA segment consisting of cfr, a truncated copy of insertion sequence IS21-558, and a region with homology to the DNA invertase gene bin3 of transposon Tn552 from Bacillus mycoides was integrated into the transposase gene tnpB of the fexA-carrying transposon Tn558. The emergence of a multidrug-resistant cfr-positive variant of ST8-MRSA-IVa/USA300 is alarming and requires ongoing surveillance. Moreover, the identification of a novel conjugative plasmid carrying the cfr gene indicates the ability of cfr to spread to other MRSA strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics*
  • Bacterial Toxins / genetics*
  • Bacterial Toxins / metabolism
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Exotoxins / genetics*
  • Exotoxins / metabolism
  • Leukocidins / genetics*
  • Leukocidins / metabolism
  • Methicillin Resistance* / genetics
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Methicillin-Resistant Staphylococcus aureus / genetics*
  • Molecular Sequence Data
  • Plasmids / genetics

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Bacterial Toxins
  • CFR protein, Staphylococcus aureus
  • Exotoxins
  • Leukocidins
  • Panton-Valentine leukocidin

Associated data

  • GENBANK/FN995110
  • GENBANK/FN995111
  • GENBANK/FR675942