Impact of enterococcus on immunocompetent and immunosuppressed patients with perforation of the small or large bowel.

Abstract

Introduction and methods: The role of enterococcus in intraabdominal infection remains controversial. A retrospective study of 473 patients with bowel perforation was conducted to assess the impact of enterococci on outcome of patients with perforation of the small and large bowel.

Results: The overall mean age was 61.4 with a gender ratio of 60/40 (m/f). We detected enterococci in 54% of all patients. In the group of enterococci-positive patients, we found Enterococcus faecalis (E. faecalis) in over 70% and Enterococcus faecium (E. faecium) in over 50%. Those in whom we detected enterococci (Pos) had a higher 90-day mortality rate than patients who were enterococci negative (Neg) (29.7%/19.4%, P 0.007). Morbidity, length of stay in intensive care unit (ICU-LOS) and length of stay in hospital (hospital-LOS) were significantly higher in the Pos group. The subgroup of Pos who received specific antimicrobial therapy against these species (Pos-treated) had a higher 90-day mortality rate than the subgroup without specific therapy (Pos-not treated) (35.5%/23.3%, P 0.04). The Pos-not treated group had higher morbidity, ICU-LOS and hospital-LOS than the Neg group. The mortality rate, ICU-LOS and hospital-LOS of immunosuppressed patients (12%) were significantly higher compared with patients not on immunosuppression with similar morbidity. We found a higher rate of E. faecium than in other studies (55.1%). However, we observed no difference in mortality and morbidity between patients infected with E. faecalis and E. faecium. In multivariate analysis, detection of enterococci did not influence mortality. Significant risk factors were age, immunosuppression, specific antimicrobial therapy and anastomotic leakage.

Conclusion: Enterococci seem to play a minor role in uncomplicated intraabdominal infections. Our results suggest that enterococci play a role in the severity of postoperative complications. In particular, detection of enterococci in patients with anastomotic leakage are suggested to be an indicator of severe illness. We found significantly higher rates of E. faecium than described before, but no significant differences in clinical outcome between E. faecalis and E. faecium. When empirical therapy against enterococci is recommended, E. faecalis and E. faecium should both be covered.