Postoperative enterococcal infection after treatment of complicated intra-abdominal sepsis

The prevalence of enterococcal isolation and factors associated with postoperative enterococcal infection remain ill defined.

A prospective longitudinal observational study was conducted of consecutive patients with a first episode of intra-abdominal infection and a positive microbiological culture who did or did not develop a postoperative septic complication involving enterococci. The prevalence of initial enterococcal isolation was determined for each focus of infection. Postoperative enterococcal infections were related to whether appropriate (piperacillin--tazobactam), suboptimal (carbapenems) or inappropriate (cefotaxime plus metronidazole) antienterococcal therapy had been administered empirically.

Enterococci were isolated in 42 (21 per cent) of the 200 patients investigated. The isolation rates were 11 per cent for community-acquired peritonitis, 50 per cent for postoperative peritonitis and 23 per cent for intra-abdominal abscesses of both origins. No enterococci were isolated from 49 patients with perforated appendicitis. Independent factors for postoperative enterococcal infection were type of intra-abdominal infection (P = 0.006), Acute Physiology And Chronic Health Evaluation (APACHE) II score greater than 12 (P = 0.04) and inappropriate empirical antibiotic cover (P = 0.05). Postoperative enterococcal infections were associated with a high mortality rate (21 versus 4 per cent; P < 0.0007).

Enterococci are frequently isolated from intra-abdominal infections of non-appendiceal origin and are often involved in postoperative infectious complications, particularly peritonitis. Empirical antibiotic therapy covering Enterococcus faecalis should be contemplated in some circumstances.