Survival of Patients With Vancomycin-Resistant Enterococcus faecium Bacteremia Treated With Conventional or High Doses of Daptomycin or Linezolid Is Associated With the Rate of Bacterial Clearance

Objectives: Vancomycin-resistant enterococci are important pathogens for healthcare-associated infections. Although linezolid is bacteriostatic and daptomycin is rapidly bactericidal against vancomycin-resistant enterococci in vitro, it is not clear whether they differ in their effect on bacterial clearance in patients with vancomycin-resistant enterococci bloodstream infections. Design: Prospective observational study. Setting: Two university hospitals and research laboratory. Patients: Patients with vancomycin-resistant enterococci bloodstream infection proven by blood cultures were prospectively enrolled from January 2010 to July 2015. Interventions: Sequential blood samples were collected. Real-time quantitative polymerase chain reaction was used to monitor bacterial loads. Measurements and Main Results: One hundred eight patients with vancomycin-resistant enterococci bloodstream infection were enrolled. Quantitative polymerase chain reaction assays were performed on 465 blood isolates. We found this method to be closely correlated with colony-forming units and more sensitive than culture. Sixty-three patients (58.3%) received "conventional dose" daptomycin (6–9 mg/kg), 15 (13.9%) received high-dose daptomycin (≥ 9 mg/kg), and 30 (27.8%) were treated with linezolid (600 mg every 12 hr) as sole agents. The initial mean bacterial load was 1.03 log10 copies/mL and unrelated to survival. Survivors had a more rapid early bacterial clearance than nonsurvivors (Δ log10 copies/mL/d; –0.16 vs 0.31; p = 0.02). Multivariable logistic regression showed that a slower early bacterial clearance independently predicted increased mortality (odds ratio, 3.21; 95% CI, 1.03–10.02; p = 0.045). Conventional dose daptomycin was associated with a significantly slower rate of bacterial clearance than high-dose daptomycin (Δ log10 copies/mL/d; –0.04 vs –0.41; p

https://ift.tt/2IxtgbL