Medical Care
The following are guidelines for antimicrobial therapy in patients with enterococcal infections. Adjust based on antibiotic susceptibility.
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Ampicillin/penicillins are the drugs of choice if the Enterococcus is susceptible.
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Ampicillin alone can be used to treat minor localized infections in an otherwise healthy host.
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Antibiotics containing beta-lactamase inhibitors (eg, clavulanate, sulbactam) can be used if resistance is due to production of beta-lactamase.
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Single drug therapy is effective treatment for urinary tract infection (UTI) and enterococcal bacteremia without endocarditis. Nitrofurantoin is an alternative to penicillins for uncomplicated UTIs. Penicillin or ampicillin plus aminoglycoside (for synergism to produce bactericidal activity) are to be used in the following:
Neonatal septicemia
Endocarditis
Meningitis
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Guidelines from the Infectious Diseases Society of America (IDSA) on intra-abdominal infections do not recommend empiric enterococcal coverage for community-acquired infections. [16] However, for hospital-acquired abdominal infections, if enterococci are isolated, antibiotic coverage is recommended.
For strains with high-level resistance to beta-lactams, aminoglycosides, and glycopeptides, quinupristin/dalfopristin (Synercid) or linezolid (Zyvox) may be used.
A 7-month-old formerly premature infant with ventriculitis secondary to E faecium who was successfully treated with a 3-week course of linezolid at a dose of 10 mg/kg/dose 3 times a day has been reported. Therapy was well tolerated. Resistance to linezolid can develop after prolonged antibiotic therapy (>21 days).
Quinupristin/dalfopristin inhibits bacterial protein synthesis and is approved for patients older than 16 years for serious or life-threatening infections associated with vancomycin-resistant E faecium bacteremia.
Synercid is not effective against E faecalis.
Endocarditis is treated as follows:
Treatment of native valve endocarditis due to susceptible strains of enterococci consists of combination therapy with parenteral ampicillin (or penicillin G) plus parenteral gentamicin (or streptomycin) for a minimum of 4-6 weeks (4 wk if symptoms are present < 3 mo vs 6 wk if symptoms are present >3 mo).
Patients with severe penicillin allergy should be treated with vancomycin plus gentamicin or streptomycin.
Endocarditis due to enterococci highly resistant to beta-lactams (usually E faecium) may be treated with vancomycin plus an aminoglycoside.
Endocarditis caused by beta-lactamase–producing strains of E faecalis can be treated with ampicillin-sulbactam plus an aminoglycoside.
Endocarditis caused by Van B strains of enterococci can be treated with high-dose ampicillin plus an aminoglycoside if resistance to these agents is not present; otherwise, teicoplanin (investigational drug in the United States) plus an aminoglycoside should be used.
For endocarditis of native or prosthetic valve due to multiple drug–resistant vancomycin-resistant E faecium, 8 weeks of linezolid is recommended. For endocarditis of native or prosthetic valve due to vancomycin-resistant E faecalis, a combination of imipenem and ampicillin or cephalosporin and ampicillin for 8 weeks is recommended.
High-dose continuous infusion ampicillin (200-300 mg/kg/d) may be an option to dosing every 4-6 hours in the treatment of nonsynergistic enterococcal endocarditis.
Doses of gentamicin for treatment of enterococcal endocarditis are aimed to reach a serum concentration peak of only 3-5 mcg/mL. The dose is 3 mg/kg/d instead of the usual 6-7.5 mg/kg/d.
Streptomycin is not usually given unless gentamicin resistance and synergism for streptomycin are present.
Meningitis and septicemia should be treated with bactericidal regimens. With meningitis, the duration of therapy is usually 2-3 weeks. If an underlying predisposing cutaneous defect is present, such as congenital cutis aplasia, 3-4 weeks of therapy may be required.
In a study of 98 adult patients with VRE bacteremia, 30 were treated with daptomycin, and 68 were treated with linezolid. [17] Daptomycin was noted to be as effective as linezolid. No elevation of creatine kinase levels or rhabdomyolysis was noted.
A study by Santos et al that characterized 132 enterococcal clinical isolates obtained from cancer patients between 2013 and 2014 found that the predominant species was E. faecalis (108 isolates) and that even though 44.7% of the isolates were multidrug-resistant, all isolates were susceptible to fosfomycin, linezolid and glycopeptides. [18]
Surgical Care
See the list below:
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Catheter-associated sepsis: Remove promptly catheter.
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Infected ventriculoperitoneal (VP) shunt: An infected VP shunt should be removed promptly and an external ventricular drain placed (ventriculostomy).
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Endocarditis due to aminoglycoside-nonsynergistic strains: Valve replacement may be necessary.
Consultations
See the list below:
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Treat patients with enterococcal infections in consultation with an infectious disease consultant.
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This photomicrograph reveals cocci-shaped Enterococcus species bacteria taken from a patient with pneumonia.
