Enterococcal Bacteremia

Ampicillin and Vancomycin-Resistant E. faecium

Rapid identification and differentiation of E. faecalis from E. faecium & other enterococci to ensure appropriate and effective therapy for antibiotic-resistant E. faecium


“PNA FISH identified E. faecium a median 2.3 days earlier and was associated with statistically significant reductions in the time to initiating effective therapy and decreased 30-day mortality.”

Forrest et al. Antimicrob Agents Chemother. 2008 Oct; 52(10): 3558-63.
 

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The Challenge

Early, Appropriate Therapy for Antibiotic-Resistant E. faecium Bacteremia

Enterococcus species are the fourth most common cause of hospital-acquired bacteremia in the US and the fifth most common in Europe.(1) Although the vast majority of these infections can be linked to two causative pathogens, Enterococcus faecalis and Enterococcus faecium, treatment decisions are difficult as each species exhibits differing antibiotic resistance profiles.

While E. faecalis is generally susceptible to ampicillin, infections with other non-faecalis enterococci, mainly E. faecium, are often resistant to both ampicillin and vancomycin. Since conventional identification methods can take up to 3 days or longer, patients with E. faecium bloodstream infections often receive inappropriate antimicrobial therapy for days leading to higher mortality and significant extra hospital costs.(2,3,4)

The challenge for clinicians is how to ensure early, appropriate therapy for patients with E. faecium bacteremia.
 
 
 

The Dilemma

Conventional Identification of E. faecium Takes 2-3 days
 
Gram Stain - GPCPC

  • Cannot distinguish E. faecalis from E. faecium & other enterococci and streptococci in Gram stain.

  • Does the Gram-positive cocci in the positive blood culture represent vancomycin (VRE) or ampicillin resistant E. faecium, ampicillin sensitive E. faecalis or streptococci?

  • When to escalate therapy for E. faecium?

  • Conventional culture and phenotypic identification can take an additional 2-3 days.

  • Clinicians can’t wait an additional 2-3 days to prescribe the appropriate antimicrobial to cover for ampicillin and/or vancomycin resistant E. faecium.
 
 

PNA FISH® Solution

Rapid Identification and Differentiation of E. faecalis from E. faecium & Other Non-faecalis Enterococci
 

E. faecalis and E. faecium & OE

  • 90 min. molecular identification and differentiation of E. faecalis (green) from E. faecium & Other Enterococci (red), directly from positive blood cultures.

  • Results 2-3 days earlier than conventional methods.

  • Proven to help:

    • Shorten time to appropriate therapy for patients with E. faecium infections.(5)

    • Reduce mortality rates for E. faecium bloodstream infections.(5)

    • Avoid unnecessary use of broad-spectrum antimicrobials (e.g. vancomycin) for E. faecalis.(5)
 
 

Proven Benefits

Ampicillin and Vancomycin Resistance in E. faecalis vs. E. faecium

Summary of data collected from 268 hospitals in the United States on 14,430 GPCPC-positive blood cultures.(6)
 
   
  • E. faecalis: 97% susceptible to ampicillin and 95% susceptible to vancomycin

  • E. faecium: 13% susceptible to ampicillin and 33% susceptible to vancomycin
 
 
 

Shorten Time to Appropriate Therapy

Quasi-experimental study of 224 patients (129 pre-intervention, 95 post-intervention) with E. faecalis and E. faecium positive blood cultures performed at the University of Maryland Medical Center (Baltimore, MD).(5)
 
 

  • Initial empiric antimicrobial therapy was inadequate for 82% of E. faecium patients in the Control Group and 87% in the PNA FISH® group

  • Reduced time to species identification for E. faecium by 2.3 days

  • Reduced time to appropriate therapy for E. faecium by 1.8 days
 
 
 

Reduce Mortality Rates for E. faecium Bacteremia

Quasi-experimental study of 224 patients (129 pre-intervention, 95 post-intervention) with E. faecalis and E. faecium positive blood cultures performed at the University of Maryland Medical Center (Baltimore, MD).(5)
 
 
  
 

 1.  Diagn Microbiol Infect Dis. 2004; 50: 59-69
 2.  Clin Infect Dis. 2002; 34: 922-929
 3.  Ann Intern Med. 2001; 135: 484-492
 4.  Infect Control Hosp Epidemiol. 2003; 24:690-698
 5.  Antimicrob Agents Chemother. 2008 Oct;52(10):3558-63
 6.  Ann Clin Micro and Antim. 2004; 3:1-8