Early Bacterial Cultures from Open Fractures - Differences Before and After Debridement

Abstract

Background: The pattern of organisms found in open fractures is important in the selection of antibiotics for prophylaxis and empirical treatment. So far, there is paucity of data on local patterns of bacteria contaminating and infecting open fractures and their antibiotic susceptibility profile. Objective: To describe the pattern and antibiotic susceptibility of bacterial isolates obtained within 24 hours of injury from open fractures and to compare these to bacterial isolates from fractures that subsequently develop infection. Methods: A prospective study of 98 patients with open fractures seen at Kenyatta National Hospital (KNH) within 24 hours of injury between November 2015 and March 2016 was conducted. Swabs for culture and sensitivity were taken from the wounds and antibiotics initiated.Surgical debridement was subsequently carried out witha 14 day follow up for wound infection. Wounds thatbecame infected were sampled for cultures And sensitivity. Results: Fifty-one (52.2%) pre debridement wound samples had positive cultures. Staphylococcus aureus and (Coagulase Negative) CON Staphylococci were the predominant gram positive isolates. At 14 days’ follow-up, the infection rate was58.9 %. The predominant gram positive isolate was Staphylococcus aureus. Only 5.7% of the pre-debridement isolates were similar to the post debridement isolates. Conclusions: The contaminating organisms are not similar to the organisms isolated from injuries that later develop infection.

Key words: Open fracture, Antibiotics, Infection, Bacterial cultures.