Microbiological and Antimicrobial Pattern of Diabetic Foot Ulcers at a Tertiary Care Center in East China.

Background: Diabetic foot infections (DFIs) are the most complex and challenging pathological state, characterized by high complexity of management, morbidity, and mortality. Empirical antimicrobial administration is needed before the identification of the causative organisms. Microbiological profile of the diabetic foot patients is the basis of the antibiotic choice for clinicians.

Methods: 76 patients visiting the Diabetic Foot Center of our Hospital for having ulcers with Wagner 3 to 5 were retrospectively surveyed for the bacterium infected. Antimicrobial susceptibility testing (AST) was implemented and the results were interpreted on the basis of the Clinical and Laboratory Standards Institute (CLSI) guidelines.

Results: A total of 92 isolates were obtained, of which 47 strains of gram-negative bacilli (GNB) accounted for 51.1%, 41 strains of gram-positive cocci (GPC) accounted for 44.6%, and 4 strains of fungi accounted for 4.3%. Species of Enterobacteriaceae and Staphylococcus are the two predominant strains. The top 4 most frequently isolated strains were Staphylococcus aureus (22.8%), enterococcus faecalis (9.8%), Pseudomonas aeruginosa (9.8%), Escherichia coli (5.4%). The rate of resistance to methicillin was 33.3% for S. aureus. The rate of extended-spectrum β-lactamases (ESBLs) production among E. coli was 60%. 50% of Klebsiella pneumoniae were resistant to carbapenems. P. aeruginosa showed high sensitivity to commonly used antibiotics. There was one isolate of Acinetobacter spp. resistant to most antimicrobials except tigecycline and aminoglycosides.

Conclusion: Enterobacteriaceae and Staphylococcus are the two predominant species. The resistance to antibiotics of S. aureus and P. aeruginosa showed optimistic results. However, the high prevalence of CRKP imposed a challenging issue for clinical physicians.