Enterococcus faecalis Infection Treatment Guidelines

Introduction to Recommended Therapies

The American Heart Association recommends against using fluoroquinolones, such as levofloxacin, as monotherapy or empirical therapy for Enterococcus faecalis infections due to their lack of reliable activity against enterococci 1
The Infectious Diseases Society of America and other major guidelines recommend beta-lactams (ampicillin or penicillin) combined with aminoglycosides as first-line therapy for enterococcal infections, with no mention of fluoroquinolones as acceptable alternatives 2, 3, 4, 5, 6

For ampicillin-susceptible E. faecalis, the preferred treatment is ampicillin 2g IV every 6 hours, with gentamicin 3 mg/kg per 24 hours IV/IM in 3 equally divided doses for synergy 1, 4, 6
The treatment duration is 4-6 weeks for endocarditis and 7-14 days for uncomplicated bacteremia with source control 1, 4
For beta-lactam allergic patients, vancomycin 30 mg/kg per 24 hours IV in 2 equally divided doses (target trough 10-15 μg/mL) is recommended, combined with gentamicin 3 mg/kg per 24 hours IV/IM in 3 equally divided doses 4, 6

Gentamicin should be administered in daily multiple divided doses rather than once-daily dosing for enterococcal infections, with a target 1-hour serum concentration of approximately 3 μg/mL and trough concentration <1 μg/mL 4, 6
Follow-up blood cultures should be obtained to document clearance of bacteremia 1
Patients with prolonged symptoms (≥3 months) require 6 weeks of therapy rather than 4 weeks 4, 6

Failure to remove infected devices or achieve source control will likely result in treatment failure, regardless of antibiotic choice 1
Transesophageal echocardiography should be performed if signs of endocarditis are present or if bacteremia persists >72 hours despite appropriate therapy 1