Managing Enterococcus faecium bloodstream infection: a Delphi document on clinical recommendations and research agenda

Background: Management of E faecium bloodstream infections (BSIs) remains debated, particularly the clinical impact of vancomycin resistance, the role of follow-up cultures, and optimal therapeutic regimens. This study aimed to reach expert consensus on these unresolved clinical domains and identify priorities for future research. Methods: We first conducted a systematic review and meta-analysis in January 20, 204 focusing on four predefined areas: mortality in E faecium BSIs compared with other BSIs, mortality in vancomycin-resistant enterococci (VRE)-BSIs compared with vancomycin-susceptible enterococci-BSIs, management of catheter-related E faecium BSIs, and 4) optimal antibiotic therapy for VRE-BSIs. These results informed a three-round Delphi process involving a panel of experts. An iterative approach was adopted: 16 initial questions developed from the systematic review (6-point Likert scale) were refined across rounds based on expert feedback. Consensus was defined as at least 80% agreement or disagreement. Findings: 13 statements were generated across three broader domains. Regarding clinical outcomes and diagnostics, experts agreed that mortality is heavily influenced by comorbidities; thus, therapeutic assessment should rely on clinical trends and inflammatory markers, with follow-up blood cultures used to confirm eradication. Catheter-related BSI should be managed with device removal and short-course (<7 days) antibiotics in selected uncomplicated cases. For therapeutic management, teicoplanin is preferred for vanB VRE-BSI. For vanA VRE-BSI, both linezolid and high-dose daptomycin (>9 mg/kg per day) are effective, reserving daptomycin-based combinations for challenging cases (deep-seated infections and/or high Minimum Inhibitory Concentrations). Finally, future trials evaluating the impact of antimicrobial therapy should use Desirability-of-Outcome-Ranking analysis; the in-vitro potential of oritavancin justifies targeted randomized trials to define its clinical efficacy in VRE-BSI. Interpretation: This paper delineates current evidence and expert consensus on management of E faecium BSI while identifying crucial knowledge gaps to guide future clinical research. Funding: None.