From the Guidelines
Enterococcus faecalis infections should be treated with linezolid 600 mg IV or PO every 12 hours, as recommended by the most recent guidelines 1. The treatment duration is dependent on the site of infection and clinical response.
- For uncomplicated urinary tract infections, a single dose of fosfomycin 3 g PO or nitrofurantoin 100 mg PO every 6 hours may be considered 1.
- For more severe infections like endocarditis, high-dose daptomycin 8-12 mg/kg IV daily may be used, especially in cases of vancomycin-resistant enterococci (VRE) 1.
- Combination therapy with an aminoglycoside (gentamicin 1 mg/kg every 8 hours) or a beta-lactam antibiotic may be added for synergistic effect in complicated infections 1.
- Tigecycline 100 mg IV loading dose then 50 mg IV q12 h may be considered for intra-abdominal infections due to VRE 1.
- High-dose ampicillin (18-30 g IV daily) or amoxicillin 500 mg PO/IV every 8 hours may be used for uncomplicated urinary tract infections due to VRE, especially if the isolate is susceptible to ampicillin 1. It is essential to note that E. faecalis is naturally resistant to many antibiotics, including cephalosporins and trimethoprim-sulfamethoxazole, making appropriate antibiotic selection crucial 1. Treatment should always be guided by susceptibility testing since resistance patterns vary, and adequate source control through drainage of abscesses or removal of infected devices is essential for successful treatment outcomes 1.
From the Research
Treatment Options for Enterococcus faecalis Infections
- The treatment of Enterococcus faecalis infections can be challenging due to the emergence of multidrug-resistant strains 2, 3.
- For asymptomatic bacteriuria with multidrug-resistant Enterococcus, routine therapy is not recommended, and removal of indwelling urinary catheters should be considered 2.
- Antibiotic therapy selection should be guided by urine culture and susceptibility results, with potential oral agents including nitrofurantoin, fosfomycin, and fluoroquinolones for acute uncomplicated urinary tract infections (UTIs) 2.
- Parenteral agents such as daptomycin, linezolid, and quinupristin-dalfopristin may be considered for the treatment of pyelonephritis and complicated UTIs caused by multidrug-resistant Enterococcus 2.
Combination Antimicrobial Therapy
- Combination antibiotic therapy has been shown to be effective in treating Enterococcus faecalis bloodstream infections and infective endocarditis, with ampicillin plus ceftriaxone emerging as a preferred treatment option 4.
- However, mortality rates remain high, and more research is needed to improve patient outcomes from this high-mortality disease 4.
- The use of aminoglycosides or rifampin as adjunctive therapy may be considered in serious infections 2.
Phage Therapy
- Phage-antibiotic synergy has been proposed as an alternative therapy for UTIs, with the potential to eliminate bacteria and reduce the development of resistant variants 5.
- The combination of phages and β-lactam antibiotics has been shown to have synergistic effects against Enterococcus faecalis strains, with the potential to reduce the number of resistant variants and impact the reproductive cycle of the phages 5.
Antibiotic Resistance and Treatment
- Enterococcus faecalis strains have been shown to have low resistance to antibiotics, while Enterococcus faecium strains have been found to have a higher proportion of vancomycin-resistant strains 6.
- Primary antibiotics suitable for treating Enterococcus faecalis infections include aminopenicillins, which may be used in combination with aminoglycosides for severe infections 6.
- For Enterococcus faecium strains, glycopeptides must be chosen, and linezolid or tigecycline may be indicated for the treatment of vancomycin-resistant Enterococcus faecium 6.