Unraveling the Enterococcus enigma in ICU peritonitis: a multicenter cohort study

BACKGROUND: The role of Enterococcus spp. and the need for specific anti-Enterococcus therapy in Intensive Care Unit (ICU) patients with peritonitis remain debated. METHODS: We conducted a retrospective multicentre cohort study including all consecutive adults admitted to the ICUs of four hospitals in western France with peritonitis between 2020 and 2022. Outcomes were compared according to Enterococcus spp. isolation and, among Enterococcus-positive cases, according to early administration (< 48 h) of active antimicrobial therapy. Propensity-weighted Cox models were used to estimate 90-day survival. RESULTS: Among 392 patients, Enterococcus spp. were isolated in 161 (41.1%). Enterococcus-positive patients were older and more frequently had postoperative and diffuse peritonitis. ICU mortality rates were 29.8% vs 28.1% in patients with and without Enterococcus infection (p = 0.805). In multivariable analysis, postoperative peritonitis (aOR 2.56 [1.67-3.95], p < 0.001), diffuse peritonitis (aOR 1.78 [1.10-2.89], p = 0.020) and solid organ transplantation (aOR 5.82 [1.18-28.76]; p = 0.031) were independently associated with Enterococcus isolation. Among the 155 patients with documented Enterococcus peritonitis and available antimicrobial treatment data, 95 (61%) received early active therapy. Early anti-Enterococcus treatment was not associated with improved 90-day survival either in the raw population (HR 0.71 [95% CI 0.39-1.27]; p = 0.241) or after weighted Cox regression (HR 0.66 [95% CI 0.37-1.18]; p = 0.160). CONCLUSIONS: Enterococcus spp. isolation appears common in ICU peritonitis but not independently associated with higher mortality. Early targeted antimicrobial therapy was not associated with a statistically significant improvement in outcomes.