Enterococcal IE on Native Cardiac Valves or Prosthetic Material Enterococcal endocarditis is relatively rare in children. Treatment is difficult because of the relative resistance of enterococci to penicillin and ampicillin (which are not bac- tericidal for enterococci) and their variable resistance to ami- noglycosides and vancomycin.120,121 The treatment regimen for native valve IE caused by susceptible strains should be a combination therapy of penicillin G or ampicillin together with gentamicin for 4 to 6 weeks, with a longer duration of therapy in cases involving prosthetic material.2,120,122 For patients with infections caused by susceptible strains of enterococci who are unable to tolerate -lactam therapy, experts recommend vancomycin combined with gentamicin for 6 weeks for native valve IE and for a minimum of 6 weeks for infection of prosthetic material.2,122 In contrast to therapy for streptococcal IE [ Streptococcal IE on Native Cardiac Valves (No Prosthetic Material) or Prosthetic Material ], the length of treatment with an aminoglycoside is for the entire course of therapy, and in patients with normal renal function, with the aminoglycoside divided into 2 to 3 doses daily rather than given in a single daily dose. The emergence of high- level vancomycin, ampicillin, and aminoglycoside resistance in some enterococcal species has further complicated treat- ment choices. The combination of ampicillin plus ceftriaxone was reported to be effective for aminoglycoside nonsuscep- tible Enterococcus faecalis strains first in a report from Spain and recently confirmed in a multi-institutional observational Enterococci are resistant to ceftriaxone and other cephalosporins, and these drugs used alone are not an option for treatment of enterococcal endocarditis. Vancomycin- resistant enterococci may cause IE, but there are too few reports in the literature to determine the most effective treat- ment. 