What is the source of Enterococcus (E) faecium bacteremia?

From the Guidelines

Enterococcus faecium bacteremia is most commonly associated with intra-abdominal infections, urinary tract infections, and central venous catheter-related infections, and identifying the source is crucial for effective treatment, which typically involves source control and appropriate antibiotic therapy, with daptomycin being a preferred option for serious VRE infections at a dosing of at least 8 mg/kg and up to 10-12 mg/kg 1. The most frequent sources of Enterococcus faecium bacteremia include:

• Intra-abdominal infections
• Urinary tract infections
• Central venous catheter-related infections
• Endocarditis
• Biliary tract infections
• Wound infections In hospitalized patients, particularly those who are immunocompromised or have received broad-spectrum antibiotics, E. faecium can translocate from the gut into the bloodstream, making source control and appropriate antibiotic therapy crucial for effective treatment. Vancomycin-resistant E. faecium (VRE) is particularly concerning and may require treatment with linezolid or daptomycin, with daptomycin being the preferred option for serious VRE infections at a dosing of at least 8 mg/kg and up to 10-12 mg/kg 1. A thorough clinical evaluation including physical examination, imaging studies, and cultures from potential sources should be performed to identify and address the primary focus of infection, as source control significantly improves outcomes in E. faecium bacteremia. The use of high-dose daptomycin has been shown to be effective in treating VRE bloodstream infections, with a 30-day mortality rate of 56% compared to standard dose daptomycin 1. Combination antimicrobial therapy may be considered in severely ill patients or those who fail treatment with traditional options, with daptomycin combined with b-lactams antibiotics showing synergistic activity in daptomycin-susceptible VRE strains 1.

From the Research

E facium Bacteremia Source

• The source of Enterococcus faecium (E faecium) bacteremia can be attributed to various factors, including:
  • Intra-abdominal site, which was found to be the most common source of bacteremia in both vancomycin-resistant E faecium (VRE) and vancomycin-susceptible E faecium (VSE) cases 2
  • Nosocomial acquisition, with all VRE and 78% of VSE bacteremia cases being hospital-acquired 2
  • Previous administration of vancomycin, which was associated with VRE bacteremia 2
  • Indwelling bladder catheters, which were also associated with VRE bacteremia 2
• Other potential sources of E faecium bacteremia include:
  • Urinary tract infections 3
  • Vascular catheters 3
  • Abscesses 3
  • Unknown sources, which accounted for 48.5% of cases in one study 3
• Underlying diseases and comorbidities that may contribute to E faecium bacteremia include:
  • Cancer 3, 4
  • Diabetes 3
  • Cirrhosis 3
  • Renal disease 3, 4
  • Chronic obstructive pulmonary disease (COPD) 3
  • Alcohol use 3
  • Glucocorticoid therapy 3
  • Prior antibiotic therapy 3, 4
  • Central venous, arterial, and urinary catheters 3
  • Mechanical ventilation 3
• The clinical characteristics and outcomes of E faecium bacteremia can be influenced by various factors, including:
  • Severity of illness 2, 4
  • Mortality rate, which was found to be higher in patients with VRE bacteremia compared to VSE bacteremia 2, 4
  • Antimicrobial susceptibility, particularly to daptomycin, which was found to be lower in E faecium isolates compared to E faecalis isolates 5