Daptomycin nonsusceptible enterococci: an emerging challenge for clinicians

Area of Science:

• Infectious Diseases
• Antimicrobial Resistance
• Clinical Microbiology

Background:

• Daptomycin is the sole FDA-approved antibiotic with in vitro bactericidal activity against vancomycin-resistant Enterococcus (VRE).
• Limited data exist on the emergence of daptomycin nonsusceptibility in enterococci.
• Understanding daptomycin nonsusceptibility is critical for managing VRE infections.

Purpose of the Study:

• To systematically review literature on daptomycin nonsusceptible enterococci.
• To assess the clinical significance and treatment outcomes of daptomycin nonsusceptibility.
• To evaluate the prevalence and potential overestimation of daptomycin nonsusceptibility in VRE.

Main Methods:

• Systematic literature review of reported cases of daptomycin nonsusceptible enterococci.
• Analysis of clinical significance and therapeutic outcomes.
• Assessment of prevalence based on Clinical Laboratory Standards Institute (CLSI) breakpoints.

Main Results:

• Daptomycin exhibits in vitro activity against over 90% of enterococcal isolates based on CLSI breakpoints.
• Less than 2% of enterococcal isolates demonstrated daptomycin nonsusceptibility (MICs >4 μg/mL).
• The prevalence of daptomycin nonsusceptibility in VRE may be overestimated due to clonal spread in healthcare settings.

Conclusions:

• Daptomycin remains a key therapeutic option for VRE infections.
• Clinicians must be aware of the potential emergence of daptomycin nonsusceptibility.
• Close monitoring of daptomycin minimum inhibitory concentrations (MICs) for enterococci during treatment is recommended.