Staphylococcus aureus strains isolated from diabetic foot ulcers. Identification of the antibiotic resistant phenotypes

Abstract

Abstract Background and aims: Infected foot ulcer is one of the most feared complications of diabetes mellitus. Staphylococcus aureus is the most frequently isolated pathogen in diabetic foot infections. The aim of this study was to evaluate the prevalence of S. aureus strains involved in producing foot infections in diabetic patients and the antibiotic resistance pattern of these strains. Material and methods: The study included 33 S. aureus strains isolated from 55 diabetic foot ulcers. The subjects were selected from the 2465 patients with diabetes mellitus hospitalized in the Timişoara Diabetes Clinic, between 2011 and 2013. Germs’ identification relied on cultural and biochemical characteristics. Final identification and antimicrobial testing were performed using the Vitek 2 (Bio Merieux France) automatic analyzer. Results: All the 55 samples collected from diabetic foot ulcers were positive. We isolated 64 bacterial strains (some samples were positive for 2 microorganisms). The most frequently isolated germ was S. aureus, in 33 samples (51.56%). All these S. aureus strains showed resistance to benzylpenicillin, while only 33.33% were methicillin-resistant (MRSA). Conclusions: The most frequently isolated germ in the wound secretions from diabetic foot ulcers was S. aureus. The highest percentage of antimicrobial resistance was recorded to benzylpenicillin and erythromycin.