Prospective, multicenter, observational study on the evaluation of efficacy of appropriate monotherapy vs combination treatment for non-complicated Enterococcus faecalis bloodstream infection (EF-BSI).

The aims of our study are:

Primary:

To compare the efficacy of appropriate monotherapy vs combination treatment for EF-BSI, according to standard of care.

Secondary:

1. To compare the impact on clinical outcome of the initial combination therapy in the subgroup of patients with enterococcal endocarditis. In this case we will evaluate only the antibiotic treatment administered before the diagnosis of endocarditis assuming that any case of endocarditis will be treated with a combination therapy.

2. To compare the efficacy of combination treatment (vs monotherapy) in the following subgroup of patients:

   A. Patients with low versus high risk of endocarditis according with the "Number of positive blood cultures, Origin of the bacteremia, previous Valve disease, Auscultation of heart murmur (NOVA) score".

   B. Patients with metastatic septic localizations. C. Patients with catheter-related BSI. D. Patients with indwelling cardiovascular device or prosthetic valve.

3. To validate the NOVA score as a predictor of enterococcal endocarditis in a large multicentre cohort of patients with EF-BSI.

4. To estimate optimal duration of treatment of EF-BSI in patients without endocarditis.

5. To evaluate the rate of 90-day development of Clostridium difficile infection.

The promoting center is S. Orsola-Malpighi Hospital is a 1,420-bed tertiary care University Hospital in Bologna with an average of 72,000 admissions per year. A dedicate team of Infectious Diseases (ID) specialists is active in the promoting center. Investigators of this team have already coordinated multicenter studies on infections topics. Centers from other countries will be invited to participate by email, they will be ask to fulfil an agreement form.

All consecutive, unselected patients with monomicrobial EF-BSI will be screened for study inclusion. We expect to enroll about 500 patients.

Period of data collection will be from september 2019 to 31th December 2020.

Inclusion Criteria:

• Adult (>18 years)
• First monomicrobial EF-BSI
• Receipt of ≥ 5 days of at least one in vitro active drug (ampicillin, amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin, vancomycin, teicoplanin, daptomycin and linezolid) with or without a synergistic drug (ceftriaxone, gentamycin, streptomycin), at common suggested dosages for EF-BSI in empirical or definitive therapy
• Written informed consent

Exclusion Criteria:

• Short term (within 3 days from BSI) mortality
• Other concomitant infection

All consecutive, unselected patients with a first episode of monomicrobial EF-BSI will be screened for study inclusion