Clinical characteristics, predisposing factors and outcomes for Enterococcus faecalis versus Enterococcus faecium bloodstream infections: a prospective multicentre cohort study.

Purposes: Enterococcal BSI is associated with significant morbidity and mortality, with fatality rates of approximately 20-30%. There are microbiological and clinical differences between E. faecalis and E. faecium infections. The aim of this study was to investigate differences in predisposing factors for E. faecalis and E. faecium BSI and to explore prognostic factors.

Methods: This study was a post-hoc analysis of PROBAC, a Spanish prospective, multicenter, cohort in 2016-2017. Patients with E. faecalis or E. faecium BSI were eligible. Independent predictors for BSI development in polymicrobial and monomicrobial BSI and in-hospital mortality in the monomicrobial group were identified by logistic regression.

Results: A total of 431 patients were included. Independent factors associated with E. faecium BSI were previous use of penicillins (aOR 1.99 (95% CI 1.20-3.32)) or carbapenems (2.35 (1.12-4.93)), hospital-acquired BSI (2.58 (1.61-4.12)), and biliary tract source (3.36 (1.84-6.13)), while congestive heart failure (0.51 (0.27-0.97)), cerebrovascular disease (0.45 (0.21-0.98)), and urinary tract source (0.49 (0.26-0.92)) were associated with E. faecalis BSI. Independent prognostic factors for in-hospital mortality in E. faecalis BSI were Charlson Comorbidity Index (1.27 (1.08-1.51)), SOFA score (1.47 (1.24-1.73)), age (1.06 (1.02-1.10)), and urinary/biliary source (0.29 (0.09-0.90)). For E. faecium BSI, only SOFA score (1.34 (1.14-1.58) was associated with in-hospital mortality.

Conclusions: The factors associated with E. faecium and E. faecalis BSI are different. These variables may be helpful in the suspicion of one or other species for empiric therapeutic decisions and provide valuable information on prognosis.