Therapeutic options for vancomycin-resistant enterococcal bacteremia

Abstract

Enterococcal infections are relatively common among hospitalized patients, likely because these organisms are commensals of human gastrointestinal and genitourinary tracts. With widespread usage of glycopeptides in both humans and livestock, vancomycin-resistant enterococci (VRE) quickly emerged. Bloodstream infections caused by these isolates are of significant concern with limited bactericidal options for treatment. Presently, daptomycin and linezolid serve as the mainstays of therapy, although resistance to both agents has been documented. Newer antimicrobials, specifically lipoglycopeptides and oxazolidinones, have been developed with in vitro activity against these organisms. However, no clinical data are available with their usage for VRE infections, let alone those in the bloodstream. This review focuses on the epidemiology, current and potential future therapeutic options for the treatment of VRE bacteremia.

Keywords:

• dalbavancin
• daptomycin
• linezolid
• oritavancin
• tedizolid
• tigecycline
• vancomycin-resistant enterococci

Financial & competing interest disclosure

JM Pogue has served on the speakers bureau and as a consultant for Cubist and on the speakers bureau for Durata, Forest and Pfizer. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Vancomycin-resistant enterococci (VRE) have established itself as a prominent colonizer and pathogen among institutionalized patients.

• The ability of VRE to persist and spread within healthcare systems poses significant public health threats and must be addressed in a multifaceted manner.

• Daptomycin, linezolid, quinupristin-dalfopristin, tetracycline and chloramphenicol have all been used successfully for the treatment of vancomycin-resistant Enterococcus bacteremia in clinical reports.

• The majority of clinical use data today is with daptomycin and linezolid. In some reports, linezolid has been associated with a survival benefit compared with daptomycin.

• In cases of daptomycin non-susceptibility and/or linezolid resistance, daptomycin combinations with either β-lactams, fosfomycin or tigecycline have clinically been used with success.

• Newly approved agent, namely tedizolid, and oritavancin display in vitro activity, against many VRE strains.