Enterococci cause UTIs, especially in pts who have undergone instrumentation; chronic prostatitis; bacteremia related to intravascular catheters; bacterial endocarditis of both native and prosthetic valves (usually with a subacute presentation); meningitis, particularly in pts who have undergone neurosurgery; soft tissue infections, particularly involving surgical wounds; and neonatal infections. These organisms can also be a component of mixed intraabdominal infections.
Treatment: Enterococcal Infections - Given low cure rates with β-lactam monotherapy, combination therapy with a β-lactam plus gentamicin or streptomycin is recommended for serious enterococcal infections. High-level resistance to aminoglycosides (i.e., minimal inhibitory concentrations of >500 and >2000 µg/mL for gentamicin and streptomycin, respectively) abolishes the synergism otherwise obtained by adding an aminoglycoside to a cell wall-active agent. This phenotype must be assessed in isolates from serious infections.
- There is burgeoning evidence that ampicillin plus ceftriaxone is as effective as ampicillin plus gentamicin in the treatment of E. faecalis endocarditis, with less risk of toxicity.
- For E. faecium isolates resistant to ampicillin:
- - Daptomycin, quinupristin/dalfopristin, or linezolid plus another active agent (doxycycline with rifampin, tigecycline, or a fluoroquinolone) may be used.
- - If daptomycin is used and if high-level resistance is not noted, an aminoglycoside should be added to the regimen.
- If high-level aminoglycoside resistance is present, two other active agents should be used.
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