What is the recommended treatment for Enterococcus gallinarum infections?

Treatment of Enterococcus gallinarum Infections

Enterococcus gallinarum infections should be treated with ampicillin or linezolid as first-line therapy, based on susceptibility testing, with combination therapy recommended for severe infections. 1, 2

Characteristics of Enterococcus gallinarum

E. gallinarum is an opportunistic pathogen with several important characteristics:

• Intrinsic low-level resistance to vancomycin (VanC phenotype) 2, 3
• Primarily causes healthcare-associated infections 2
• Common sites of infection include bloodstream, urinary tract, and surgical wounds 2
• Increasing prevalence in patients with hepatobiliary or oncohematological disorders 2

Treatment Algorithm

First-Line Options (based on susceptibility testing)

• Ampicillin: 200 mg/kg/day IV divided every 6 hours 4

  • Preferred for susceptible isolates
  • Can be combined with gentamicin for synergistic effect in severe infections

• Linezolid: 600 mg IV every 12 hours 1, 5

  • Effective alternative, especially for ampicillin-resistant strains
  • Demonstrated efficacy in case reports of E. gallinarum infections 5

Alternative Options

• Daptomycin: 8-12 mg/kg IV daily 1, 6

  • Effective for severe infections
  • Has been successfully used in combination with gentamicin for E. gallinarum sepsis 6

• Meropenem: For mixed infections (particularly with gram-negative organisms) 5

Treatment Duration

• Uncomplicated infections: 7-14 days 4
• Bloodstream infections: 10-14 days 1
• Endocarditis: 4-6 weeks 1

Special Considerations

Catheter-Related Bloodstream Infections

For E. gallinarum bloodstream infections associated with central venous catheters:

1. Catheter management:

   • Remove catheter if possible, especially with persistent bacteremia 4
   • If retention is necessary, antibiotic lock therapy should be considered 4

2. Antibiotic therapy:

   • 10-14 days of systemic antibiotics 4, 1
   • Consider combination therapy for severe or persistent infections 6

Mixed Infections

E. gallinarum often occurs in polymicrobial infections, particularly in biliary tract infections:

• Tailor therapy to cover all isolated organisms 5
• For biliary infections with E. gallinarum and gram-negative organisms, consider combination therapy with linezolid plus meropenem or another appropriate agent 5

Monitoring and Safety

• Regular monitoring of renal function with aminoglycoside therapy 1
• Monitor for development of high-level resistance to glycopeptides, which has been reported 7
• For daptomycin therapy, monitor creatine kinase levels regularly 1

Infection Control Considerations

Unlike VanA/VanB resistance in E. faecium/E. faecalis, the VanC resistance in E. gallinarum is chromosomally encoded and not typically transmissible. However:

• Evaluate infection control measures on a case-by-case basis 2
• Enhanced precautions may be needed for epidemic outbreaks or isolates suspected of harboring transmissible resistance elements 2, 7

Pitfalls and Caveats

• Cephalosporins should be avoided as enterococci are intrinsically resistant 1
• E. gallinarum may be misidentified as vancomycin-resistant E. faecium in some laboratory tests
• Single-drug therapy may be insufficient for severe infections; consider combination therapy 1, 6
• Susceptibility testing is crucial as resistance patterns can vary significantly