Epidemiology of vancomycin-resistant Enterococcus faecalis: a case-case-control study

Antimicrob Agents Chemother. 2013 Jan;57(1):49-55. doi: 10.1128/AAC.01271-12. Epub 2012 Oct 15.

Abstract

Although much is known about vancomycin-resistant (VR) Enterococcus faecium, little is known about the epidemiology of VR Enterococcus faecalis. The predilection of VR E. faecalis to transfer the vancomycin resistance determinant to Staphylococcus aureus is much greater than that of VR E. faecium. The epidemiology of VR E. faecalis has important implications regarding the emergence of vancomycin-resistant S. aureus (VRSA); 8 of 13 reported VRSA cases have been from Michigan. A retrospective case-case-control study was conducted at the Detroit Medical Center, located in southeastern Michigan. Unique patients with VR E. faecalis infection were matched to patients with strains of vancomycin-susceptible (VS) E. faecalis and to uninfected controls at a 1:1:1 ratio. Five hundred thirty-two VR E. faecalis cases were identified and were matched to 532 VS E. faecalis cases and 532 uninfected controls. The overall mean age of the study cohort (n = 1,596) was 63.0 ± 17.4 years, and 747 (46.8%) individuals were male. Independent predictors for the isolation of VR E. faecalis (but not VS E. faecalis) compared to uninfected controls were an age of ≥65 years, nonhome residence, diabetes mellitus, peripheral vascular disease, exposure to cephalosporins and fluoroquinolones in the prior 3 months, and immunosuppressive status. Invasive procedures and/or surgery, chronic skin ulcers, and indwelling devices were risk factors for both VR E. faecalis and VS E. faecalis isolation. Cephalosporin and fluoroquinolone exposures were unique, independent predictors for isolation of VR E. faecalis. A majority of case patients had VR E. faecalis present at the time of admission. Control of VR E. faecalis, and ultimately VRSA, will likely require regional efforts focusing on infection prevention and antimicrobial stewardship.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / pharmacology*
  • Case-Control Studies
  • Catheters, Indwelling / microbiology
  • Cephalosporins / pharmacology*
  • Cohort Studies
  • Comorbidity
  • Diabetes Mellitus / drug therapy
  • Diabetes Mellitus / epidemiology*
  • Diabetes Mellitus / microbiology
  • Drug Resistance, Multiple, Bacterial / drug effects
  • Enterococcus faecalis / drug effects*
  • Enterococcus faecalis / growth & development
  • Enterococcus faecalis / isolation & purification
  • Female
  • Fluoroquinolones / pharmacology*
  • Gram-Positive Bacterial Infections / drug therapy
  • Gram-Positive Bacterial Infections / epidemiology*
  • Gram-Positive Bacterial Infections / microbiology
  • Humans
  • Immunocompromised Host
  • Male
  • Michigan / epidemiology
  • Microbial Sensitivity Tests
  • Middle Aged
  • Risk Factors
  • Vancomycin Resistance / drug effects

Substances

  • Anti-Bacterial Agents
  • Cephalosporins
  • Fluoroquinolones