Emergence of daptomycin resistance following vancomycin-unresponsive Staphylococcus aureus bacteraemia in a daptomycin-naïve patient--a review of the literature

Eur J Clin Microbiol Infect Dis. 2011 May;30(5):603-10. doi: 10.1007/s10096-010-1128-3. Epub 2010 Dec 30.

Abstract

A patient developed a daptomycin-resistant methicillin-resistant Staphylococcus aureus (MRSA) infection, despite being daptomycin-naïve, in the setting of persistent bacteraemia secondary to vertebral osteomyelitis. Modified population analysis profiling of sequential MRSA blood culture isolates revealed transition from a vancomycin-susceptible phenotype to a vancomycin-intermediate S. aureus (VISA) phenotype through a vancomycin-heteroresistant S. aureus (hVISA) intermediary. Increased cell wall thickening, determined by transmission electron microscopy, correlated with the emergence of daptomycin resistance. This case supports the current hypothesis that MRSA with reduced glycopeptide susceptibility are less susceptible to daptomycin because of a thickened cell wall. This may have significance for the use of daptomycin in salvage therapy. Other predictors of daptomycin resistance include bacteraemic persistence and the presence of high inoculum infections. As resistance may appear de novo and be unstable in vivo, all isolates should have daptomycin susceptibility testing performed. The optimal antibiotic option for salvage therapy of these daptomycin-resistant infections is unknown. However, these findings emphasise the importance of optimising management, including the consideration of early surgical intervention to avoid the emergence of daptomycin resistance, especially in high inoculum infections.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Bacteremia / drug therapy
  • Bacteremia / microbiology*
  • Cell Wall / ultrastructure
  • Daptomycin / pharmacology*
  • Daptomycin / therapeutic use
  • Drug Resistance, Bacterial*
  • Humans
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Methicillin-Resistant Staphylococcus aureus / ultrastructure
  • Microscopy, Electron, Transmission
  • Osteomyelitis / complications
  • Staphylococcal Infections / drug therapy
  • Staphylococcal Infections / microbiology*
  • Vancomycin / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Vancomycin
  • Daptomycin