At this time, the writing group does not have a prefer- ence for one regimen over the other but rather advocates an individualized approach to regimen selection for each patient. Recommendations 1. Therapy that includes either ampicillin or aqueous crystalline penicillin G plus gentamicin or ampicil- lin plus ceftriaxone is reasonable (Class IIa; Level of Evidence B). 2. Either 4 or 6 weeks of therapy is reasonable for NVE, depending on the duration of IE symptoms before the initiation of therapy if ampicillin or peni- cillin plus gentamicin is used (Class IIa; Level of Evidence B). 3. Six weeks of therapy is reasonable if ampicillin plus ceftriaxone is selected as the treatment regimen, regardless of symptom duration (Class IIa; Level of Evidence B). 4. Six weeks of antimicrobial therapy is reasonable for PVE (Class IIa; Level of Evidence B). 5. Streptomycin should be avoided in patients with creatinine clearance <50 mL/min (Class III; Level of Evidence B). 6. If the strain of Enterococcus is susceptible to both gentamicin and streptomycin, it is reasonable to use gentamicin rather than streptomycin for therapy (Class IIa; Level of Evidence C). 7. When gentamicin therapy is not an option, then a double -lactam regimen (see later section) is rea- sonable (Class IIa; Level of Evidence B). E faecalis IE Susceptible to Penicillin, Resistant to Aminoglycosides, or Gentamicin Resistant and Streptomycin Susceptible Aminoglycoside resistance in enterococci is most commonly the result of the acquisition of plasmid-mediated aminoglyco- side-modifying enzymes. E faecalis strains resistant to high levels of gentamicin are resistant to most other aminoglyco- sides, although some of them are susceptible to streptomycin. The regimens for E faecalis IE with strains that are penicil- lin-susceptible and aminoglycoside-resistant are shown in Table 13. Ceftriaxone-ampicillin therapy is reasonable and is given for 6 weeks. 