Antibiotic susceptibility of bacteria isolated from diabetic foot infections and prospects for empiric antibiotic therapy in Ouagadougou (Burkina Faso)

Introduction: The aim of this study was to study the antibiotic susceptibility of bacteria isolated from diabetic foot infections to help improve empiric antibiotic prescription in Ouagadougou, where bacteriological testing is rarely possible. Method: This cross-sectional study took place from July 1, 2011, to June 30, 2012, in the departments of internal medicine and general and gastrointestinal surgery in the Yalgado Ouedraogo teaching hospital. Bacteria were isolated from diabetic foot infections and their antibiotic sensitivity was tested by the qualitative method (Kirby-Bauer). Results: The study included 64 patients, with a median age of 57 years (interquartile range: 48-75) and a M/F sex ratio of 1.37. Among them, 39 had received antibiotics before hospitalization. Among the 71 samples, 62 cultures (87%) were positive: 53 for a single microbe (85%) and 9 for two microbes (15%). Microorganisms were mainly aerobic and anaerobic Gram-positive cocci (76%), including Staphylococcus aureus (SA) (33%) and Streptococcus spp (18%). These Gram-positive cocci were highly sensitive to amoxicillin-clavulanic acid and oxacillin. No methicillin-resistant SA (MRSA) were isolated. Enterobacteriaceae (24 %) were highly susceptible to imipenem and ticarcillin, but not to ceftriaxone or ciprofloxacin. No extended-spectrum beta-lactamase Enterobacteriaceae (ESBL) were isolated. Pseudomonas aeruginosa was highly susceptible to ciprofloxacin and imipenem. Conclusion: Despite our study's limitations, our findings show that most diabetic foot infections can be successfully treated with standard antibiotics.