Treatment Options for Enterococcus Bacteremia
For Enterococcus bacteremia, high-dose daptomycin (10-12 mg/kg/day IV) in combination with a beta-lactam such as ampicillin or ceftaroline is strongly recommended as the backbone of therapy, especially for vancomycin-resistant Enterococcus (VRE) bacteremia. 1
First-Line Treatment Options Based on Susceptibility
For Vancomycin-Susceptible Enterococcus (VSE):
- Ampicillin 2g IV every 6 hours is the preferred treatment for ampicillin-susceptible enterococci 2
- For patients with beta-lactam allergy, vancomycin is an appropriate alternative 2
- Treatment duration should be 7-14 days for uncomplicated bacteremia if source control is achieved 1
For Vancomycin-Resistant Enterococcus (VRE):
- Linezolid 600 mg IV or PO every 12 hours is strongly recommended for enterococcal infections (Strong recommendation, low quality of evidence) 2, 3
- High-dose daptomycin 8-12 mg/kg IV daily, preferably in combination with beta-lactams (penicillins, cephalosporins, or carbapenems) is recommended for VRE bacteremia (Weak recommendation, low quality of evidence) 2, 1
- Tigecycline 100 mg IV loading dose followed by 50 mg IV every 12 hours can be considered, particularly for intra-abdominal infections due to VRE 2
Special Considerations for Catheter-Related Bacteremia
- For enterococcal catheter-related bloodstream infections (CRBSI), catheter removal is strongly recommended, especially for short-term catheters 2
- If a long-term catheter cannot be removed, antibiotic lock therapy should be used in addition to systemic therapy 2, 4
- An antibiotic lock protocol permits catheter salvage in approximately 61% of hemodialysis patients with Enterococcus CRBSI 4
Evaluation for Endocarditis
- Transesophageal echocardiography (TEE) should be performed if the patient has:
Treatment Duration
- Uncomplicated bacteremia with source control: 7-14 days 1
- Complicated bacteremia or endocarditis: at least 6 weeks 1
- For catheter-related infections where the catheter is retained, follow-up blood cultures should be obtained and the catheter removed if bacteremia persists >72 hours after initiation of appropriate antibiotic therapy 2
Treatment of Panresistant Enterococcus faecium
- For strains resistant to standard therapies, combination approaches may be necessary:
- High-dose daptomycin plus ampicillin or ceftaroline shows synergistic activity 1
- High-dose continuous infusion ampicillin/sulbactam plus gentamicin has been successful in case reports 5
- Chloramphenicol may be considered as a salvage option for VRE bloodstream infections, with reported clinical response rates of 61% 2
Monitoring and Follow-up
- Obtain follow-up blood cultures to document clearance of bacteremia 1
- For patients receiving linezolid, monitor complete blood counts weekly due to risk of bone marrow suppression with prolonged use 1, 6
- For daptomycin therapy, monitor creatine phosphokinase levels weekly 1
Important Pitfalls to Avoid
- Cephalosporins and aminoglycosides as monotherapy are ineffective against enterococci, leading to high rates (43%) of inefficient empirical therapy 7
- Standard doses of daptomycin (6 mg/kg/day) are inadequate for treating resistant E. faecium; higher doses (10-12 mg/kg/day) are required 1
- Daptomycin monotherapy has been associated with treatment failures and development of resistance during therapy 1
- Failure to remove infected devices or achieve source control will likely result in treatment failure 1
- Linezolid is bacteriostatic against enterococci, which may limit its effectiveness in endovascular infections 6
Cost-Effectiveness Considerations
- Empiric use of antimicrobials with activity against VRE (daptomycin or linezolid) may be cost-effective compared to vancomycin or beta-lactam therapy for suspected enterococcal bacteremia, particularly in settings with high VRE prevalence 8