From the Guidelines
Ampicillin is the most effective treatment for Enterococcus infections in feces or urine, and it is recommended as the first-line therapy. According to the study 1, ampicillin is the drug of choice for enterococcal infections, and high doses (18-30 g IV daily) or amoxicillin (500 mg PO/IV every 8 h) are suggested to achieve sufficient urinary concentrations. This is because Enterococci have intrinsic resistance to clindamycin, making it ineffective against these bacteria, and while ciprofloxacin may show some activity against certain Enterococcus strains, resistance is common and increasing 1.
Some key points to consider when treating Enterococcus infections include:
- Differentiating colonization from true infection prior to empiric prescription of anti-VRE antimicrobial agents 1
- Using high doses of ampicillin or amoxicillin to achieve sufficient urinary concentrations 1
- Considering combination therapy with an aminoglycoside (such as gentamicin) or vancomycin for more serious infections or resistant strains 1
- Completing the full course of antibiotics even if symptoms improve before completion
It's also important to note that susceptibility testing is crucial for guiding appropriate therapy, as Enterococci are naturally resistant to many antibiotics 1. In addition, novel agents such as eravacycline and ceftaroline have been shown to exhibit in vitro activity against Gram-positive organisms, but there is currently no complete evidence available to provide guidance on their role for VRE infections 1.
Overall, the most effective treatment for Enterococcus infections in feces or urine is ampicillin, and it is recommended as the first-line therapy, with consideration of combination therapy and susceptibility testing as needed.
From the FDA Drug Label
Ciprofloxacin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections... Aerobic gram-positive microorganisms Enterococcus faecalis (Many strains are only moderately susceptible.) The MIC values should be interpreted according to the following criteria: For testing aerobic microorganisms other than Haemophilus influenzae , Haemophilus parainfluenzae, and Neisseria gonorrhoeaea: MIC (μg/mL)Interpretation ≤ 1 Susceptible (S) 2 Intermediate (I) ≥ 4 Resistant (R)
The FDA drug label does not provide a direct comparison of the effectiveness of clindamycin and ciprofloxacin for treating Enterococcus infections in feces or urine. However, it does state that many strains of Enterococcus faecalis are only moderately susceptible to ciprofloxacin.
- Key points:
- Ciprofloxacin is active against Enterococcus faecalis, but many strains are only moderately susceptible.
- The label does not provide information on the effectiveness of clindamycin for treating Enterococcus infections.
- The label does not provide a direct comparison of the effectiveness of clindamycin and ciprofloxacin for treating Enterococcus infections in feces or urine. 2
From the Research
Effectiveness of Clindamycin and Ciprofloxacin for Treating Enterococcus Infections
- The effectiveness of clindamycin and ciprofloxacin for treating Enterococcus infections in feces or urine is not directly compared in the provided studies 3, 4, 5, 6, 7.
- However, the studies suggest that:
- Ciprofloxacin resistance is common in Enterococcus faecalis strains isolated from patients with complicated urinary tract infections, with 47% of strains resistant to ciprofloxacin 5.
- Clindamycin is not mentioned as a treatment option for Enterococcus infections in the provided studies.
- Other antibiotics, such as ampicillin, nitrofurantoin, and fosfomycin, are recommended for treating Enterococcus infections, including those caused by vancomycin-resistant enterococci (VRE) 3, 4, 6.
- Daptomycin and linezolid have demonstrated clinical efficacy against VRE, but their use is generally reserved for complicated infections or those caused by ampicillin-resistant strains 3, 6.
Antibiotic Resistance Patterns
- Enterococcus faecalis and Enterococcus faecium exhibit different antibiotic resistance patterns, with E. faecium being more resistant to penicillin, tetracycline, and ciprofloxacin 7.
- High-level resistance to aminoglycosides is common in Enterococcus strains, with 17% of E. faecalis and 29% of E. faecium strains demonstrating high-level resistance to gentamycin and/or streptomycin 7.
- The use of antibiotics, such as ciprofloxacin, can select for resistant strains, making treatment more challenging 5.
Treatment Options
- For uncomplicated urinary tract infections caused by Enterococcus, nitrofurantoin, fosfomycin, or amoxicillin may be effective treatment options 3, 4, 6.
- For complicated infections or those caused by VRE, daptomycin, linezolid, or quinupristin-dalfopristin may be considered, although their use should be guided by susceptibility testing and clinical experience 3, 4, 6.