Microbiological pattern of diabetic foot infections at a tertiary care center in a developing country

To determine the microbiological profile and antibiotic susceptibility patterns of organisms isolated from diabetic foot ulcers in a tertiary care hospital Karachi, Pakistan.

This descriptive study was conducted at the Baqai Institute of Diabetology and Endocrinology (BIDE), from January 2013 to March 2014. Bone, pus and tissue samples were collected from 342 patients with diabetic foot infections and inoculated on appropriate media. Antibiotic susceptibility tests were done by Kirby Bauer disk diffusion method.

A total of 671 aerobic bacteria were isolated from 473 specimens with an average of 1.45 isolates per specimen. Poly-microbial infection was 56.87%. Gram- negative isolates were predominant 76.27%.Staphylococcus aureus was most frequent among Gram-positive 20.7% and Escherichia coli 15.72% in Gram negative isolates. MRSA was found in 26.76% Staphylococcus aureus. About 33.48% of antimicrobial resistant isolates were observed.

In our study, Gram negative aerobes were predominant in the diabetic foot infections. A significant number of MDR isolates were also observed in this cohort. Delayed referral and inappropriate use of broad spectrum antibiotics may be the main cause of increase in the frequency of MDR isolates.