ATYPICAL SEPSIS OF OPEN LEG FRACTURE: MANAGEMENT OF PATIENTS WITH BACILLUS CEREUS INFECTION

Abstract

Purpose: Prevention of post-trauma infections is basically aimed at streptococcal, staphylococcal and anaerobic germs. An increasing number of open fractures are however contaminated with Bacillus cereus leading to a multidisciplinary discussion involving infectious disease specialists, orthopaedic surgeons, and bacteriologists concerning the appropriate management. Bacillus is an ubiquitous genus of sporulated telluric Gram positive germs found in soil and plants. B. cereus can lead to local wound infection. This environmental (including hospital) bacterium is often a temporary host of the skin flora and its isolation can be taken as a simple contamination with no therapeutic consequence. B. cereus is sensitive to fluoroquinolones.

Material and methods: Between August 1995 and December 2000, B. cereus was isolated in 41 patients from surgical specimens taken from deep muscle and bone tissues. Ordinary medium was used for culture. Genomic analysis was used to type the Bacillus. Statistical analysis was conducted in cooperation with the epidemiology unit.

Results: In our unit, isolation of B. cereus was significantly associated with severe open leg fractures (Gustilo grades IIA and IIIB) with soil contamination. Samples were taken due to fever, wound discharge, elevation of C reactive protein despite antibiotic prophylaxis beyond 48 hours using the standard protocol of aminopenicillin + betalactamase inhibitor, constantly inactive against B. cereus. The strains identified presented different genomic types ruling out nosocomial contramination. One amputation, one chronic osteitis and one anteriolateral leg compartment necrosis resulted from B. cereus infection in this series.

Conclusion: Arguments developed here allow us to recall the importance of careful surgical debridement of open fractures and to emphasise the requirement for bacteriological samples and appropriate antibiotic therapy for 48 hours, combining, in agreement with the 1998 Consensus Conference, aminopenicillin + betalactamase inhibitor and gentamycin which is active against B. cereus. Severe open leg fractures which follow an unfavourable course should suggest possible B. cereus infection requiring early antibiotic therapy using a regimen with good bone diffusion including a fluoroquinolone which is always active against B. cereus.