PDB49 - Development of Antibiogram for Management of Aerobic Bacterial Infection in Diabetic Foot Ulcer

Abstract

Objectives: To determine antimicrobial susceptibility (AMS) pattern of aerobes in diabetic foot infections (DFIs). Methods: A cross-sectional study was conducted for a period of 3 years at the Department of Surgery, Kasturba hospital, Manipal, India, with 260 DFUs patients. These patients’ culture specimens (swab/pus/tissue)were observed as Gram-stained smears and cultured aerobically on blood agar and MacConkey agar plates. AMS test was performed by disc diffusion technique according to CLSI guidelines. Results: A total of 354 microbes were isolated from the ulcer wounds of 213 DFU patients, with an average of 1.7 organisms per lesion.Monomicrobial infections were less common (n= 81; 31.2%) than polymicrobial infections (n= 132; 50.7%). Gram-negative bacteria were the most common among the isolates (n= 192; 54.2 %). Aerobic Gram-positive Cocci accounted for 162 (45.8%) of all isolates. On the other hand, Staphylococcus aureus was the most frequently isolated aerobe (n= 106; 29.9%) followed by Pseudomonas aeruginosa (n= 91; 25.7%).AMS data from our study recommends that doxycycline would be the appropriate choice as single drug for empirical coverage for Gram-positive organisms. Second choices are TMP/SMX (except for Enterococcus spp.) and gentamicin (except for MRSA) for Gram-ositive organisms. The most appropriate antibiotic for Gramnegative organisms is meropenem. Second choices for Gram-negative pathogens are amikacin (except for E.coli), cefoperazone/sulbactam (except for Acinetobacter) and piperacillin/tazobactam (except for K.oxytoca). One of the critical observations is the presence of Acinetobacter, an MDR isolated from DFIs, which is either relatively or totally resistant to all the AMAs tested. Conclusions: The cumulative AMS patterns (Antibiogram) show that there is no single effective AMA for treating all aerobic bacteria inDFIs. Hence we recommend the implementation of antimicrobial stewardship program in hospitals for improving individual patient outcomes,reduce the overall burden of AMR and save healthcare cost, especially in resource poor settings like Indian healthcare system.