Bacteriological investigation of infected pressure ulcers in spinal cord-injured patients and impact on antibiotic therapy

Study design: Retrospective. Objectives: To improve the use of bacteriological results for treating spinal cord-injured patients with infected pressure ulcers. Setting: Microbiology and Orthopaedics Department, Ambroise Paré University Hospital, Boulogne-Billancourt, France. Methods: Tissue specimens, sampled at the end of the surgical intervention from unbridled and cleaned ulcers were analysed. Drainage liquids were cultured at day 1 (D1) and day 5 (D5) postsurgery. For part of the patients, a presurgery superficial sample was analysed and compared with the surgical and postsurgical samples. Results: In all, 168 surgical samples from 101 patients, 183 D1 and 104 D5 wound drainage liquids were included in this study. Out of the 168 surgical samples 17 (10%) had a negative culture, whereas 151 (90%) had a positive culture. For drainage liquids, the culture was negative in 48% and 56% of the samples at D1 and D5, respectively. The most frequently isolated species were enterobacteria, followed by staphylococci and streptococci. Conclusion: Culturing deep tissue specimens sampled from the surgically cleaned and unbridled ulcers allows for the isolation of the bacterial species that are really involved in the ulcer infection. As the identification of these bacteria and their antibiotic susceptibility are available, when the culture results of the D1 postsurgical drainage liquid is also available, it is easier to choose targeted antibiotic treatment.