Antimicrobial Susceptibility Pattern in Diabetic Foot Ulcer: A Pilot Study

Abstract

Background: Diabetic foot infections (DFIs) are major public health problems and knowledge of microbes that cause infections are helpful to determine proper antibiotic therapy.

Aims: The aim was to investigate the antimicrobial susceptibility pattern of microbes in DFIs.

Subjects and Methods: A cross.sectional study was conducted for a period of 6 months at the Department of General Surgery, KMC hospital, Manipal University, Manipal, India. During this period, 108 patients having DFIs admitted in the general surgery wards were tracked from the hospital data management system. These patientsf pus samples were examined as Gram.stained smear and cultured aerobically on blood agar and MacConkey agar plates. Antimicrobial susceptibility test was performed by disc diffusion techniques according to Clinical and Laboratory Standards Institute guidelines.

Results: Of the 108 specimens of the diabetic foot lesions, culture showed polymicrobial growth in 44.4% (48/108). Prevalence of Gram-negative
organisms (56%, 84/150) was found to be more than Gram.positive organisms (44%, 66/150). However, Staphylococcus aureus was the most frequent pathogen (28%, 42/150). All Gram-positive aerobes were sensitive to doxycycline. All Gram-negative isolates, including extended spectrum beta lactamase producing strains of Proteus mirabilis and Klebsiella
oxytoca except Acinetobacter were highly sensitive to amikacin, cefoperazone/sulbactam, and meropenem. Acinetobacter was completely resistant to all the common antibiotics tested.

Conclusion: Prevalence showed Gram-negative bacteria was slightly more than Gram-positive bacteria in diabetic foot ulcers. This study recommends doxycycline should be empirical treatment of choice for Gram-positive isolates and amikacin, cefoperazone/sulbactam, and meropenem should be considered for most of the Gram.negatives aerobes.

Keywords: Antibiotic resistance, Antimicrobial susceptibility, Diabetic foot infection, Diabetic foot ulcer, Multidrug-resistant organism