Impact of vanA-positive Enterococcus faecium exhibiting diverse susceptibility phenotypes to glycopeptides on 30-day mortality of patients with a bloodstream infection.

Introduction: This study was performed to evaluate the impacts of vanA-positivity of Enterococcus faecium (EFM) exhibiting diverse susceptibility phenotypes to glycopeptides on clinical outcomes in patients with a bloodstream infection (BSI) through a prospective, multicenter, observational study.Methods: A total of 509 patients with an EFM BSI from eight sentinel hospitals in South Korea during a two-year period were enrolled in this study. Risk factors of the hosts and causative EFM isolates were assessed to determine associations with the 30-day mortality of EFM BSI patients via multivariable logistic regression analyses.Results: The vanA gene was detected in 35.2% (179/509) of EFM isolates; 131 EFM isolates exhibited typical VanA phenotypes (group vanA-VanA), while the remaining 48 EFM isolates exhibited atypical phenotypes (group vanA-Atypical), including VanD (n = 43) and vancomycin-variable phenotypes (n = 5). A multivariable logistic regression indicated that vanA-positivity of causative pathogens was independently associated with the increased 30-day mortality rate in the patients with an EFM BSI; however, there was no significant difference in the survival rates between the patients of the vanA-VanA and vanA-Atypical groups (log-rank test, P = 0.904).Conclusions: A high 30-day mortality rate was observed in patients with vanA-positive EFM BSIs, and vanA-positivity of causative EFM was an independent risk factor for early mortality irrespective of the susceptibility phenotypes to glycopeptides; thus, intensified antimicrobial stewardship is needed to improve clinical outcome of patients with vanA-positive EFM BSI.