Abstract:
Background: Diabetes is a leading non-communicable disease in the world. Diabetic foot
ulcers are one of the most common devastating complications in diabetic patients. Diabetic foot
ulcers are predominantly caused by multidrug resistant (MDR) polymicrobial flora. Biofilm
formation is an important pathophysiology in diabetic foot ulcers.
Objectives: To determine the types of bacteria, antibiotic sensitivity patterns of bacteria,
isolated from chronic foot ulcers in diabetic patients at Teaching Hospital Karapitiya.
Methods: A prospective cross-sectional study was performed using convenient sampling
method. Deep wound swabs were collected from 50 diabetic patients with chronic foot ulcers.
All the samples were processed according to the Clinical and Laboratory Standards Institute
guidelines and antibiotic sensitivity test was carried out using the disc diffusion method. MDR
clinical isolates were subjected for the detection of biofilm formation using tissue culture plate
method. Data were statistically analysed using SPSS version 25.0.
Results: A total of 76 bacterial isolates were obtained from 50 patients with chronic diabetic
foot ulcers. The age group ranged from 38 to 80 years. Most of the cases were polymicrobial
(58.0%). Majority of isolated pathogens were Gram negative bacilli (53.9%). Most commonly
isolated pathogens were Staphylococcus aureus (28.9%) followed by Proteus spp. (19.7%),
Pseudomonas spp. (18.5%), Acinetobacter (11.9%), Coagulase negative Staphylococci (7.9%),
Diphtheroid (6.6%), Escherichia coli (3.9%) and Enterococci spp. (2.6%). Out of the isolates,
32 (42.1%) had multidrug resistance and among them 14 isolates (43.8%) expressed biofilm
formation. Biofilm formation has a significant relationship with isolation of MDR organisms
(p<0.05).
Conclusions: Polymicrobial infections due to Gram negative organisms were the commonest in
chronic diabetic foot ulcers. S. aureus was the predominantly isolated organism. Biofilm
formation had a significant relationship with the isolation of MDR organisms from diabetic foot
ulcers. As significant number of MDR cases were isolated, knowledge on the antibiotic
susceptibility pattern of the isolates from diabetic foot infections is vital to design new treatment
patterns.
