Controversy remains as to whether Enterococcus faecalis recovered from intra-abdominal infections (IAI) requires targeted therapy. Ertapenem is a broad-spectrum antibiotic with activity against a range of gram-positive, gramnegative, and anaerobic gastrointestinal organisms but with limited activity against E. faecalis. The authors report a multicenter observational study in various Hospitals in the Johns Hopkins Health System comparing the clinical outcomes of patients with cIAIs and adequate source control with intra-abdominal cultures growing E. faecalis who received ertapenem or piperacillin-tazobactam (PTZ), which has activity against E. faecalis. The primary outcome in this retrospective study was a clinical failure within 30 days of presentation which was a composite outcome including an unplanned subsequent intra-abdominal intervention, additional, unplanned antibiotic courses related to the original IAI, or death.
Totally 216 patients were included, 65 patients (30%) received ertapenem and 151 patients (70%) received PTZ. Demographic characteristics, the severity of illness, immunocompromised status and pre-existing medical conditions were generally similar between the two groups. Overall, 13 (20%) patients receiving ertapenem and 36 (24%) patients receiving PTZ had the outcomes of (1) an unplanned additional intra-abdominal surgical intervention [15% for ertapenem vs. 14% for PTZ]; (2) readmission requiring antibiotics related to the original surgery [17% for ertapenem vs. 16% for PTZ]; or (3) mortality [0% for ertapenem vs. 5% for PTZ], all within 30 days, with none of these differences reaching statistical significance. There was no difference in the 30-day composite outcome (including patients who achieved any of the aforementioned outcomes) between the ertapenem and PTZ groups (OR 0.80; 95% CI 0.39-1.63). Overall, the benefit of covering for E. faecalis in abdominal infections with optimal source control is at best doubtful.