Bacteriological Profile and Antibiotic Sensitivity Pattern in Infected Diabetic Foot Ulcers

Abstract

Objectives: To identify the common bacterial pathogens responsible for infection in diabetic foot ulcer and their sensitivity pattern to different antibiotics.
Methods: This prospective observational study was conducted from 24th June 2019 to 27th December 2019 at Services Institute of Medical Sciences Lahore. Specimens of discharge from diabetic foot ulcers (DFU) were received from Diabetes Management Centre (DMC). Cultures were put up and bacteria isolated were identified by standard methods. Antibiotic sensitivity was determined by Kirby-Bauer disc diffusion method.
Results: Samples from DFU of 50 patients were processed. Thirty-six (72%) samples were from males and 14(28%) were from females; mean age of patients was 53±9.5 years. Forty-nine (98%) patients had unsatisfactory glycemic control. Forty three (86%) samples were growth positive while 07(14%) were bacteriologically sterile. Monomicrobial infection was observed in 38 (76%) cases while polymicrobial infection was seen in 12 cases (24%). The most common isolates were Staphylococcus aureus 14(28%), Pseudomonas species 11 (22%) and Proteus species 10 (20%). Forty three percent of Staphylococcus aureus, were methicillin resistant (MRSA). All MRSA remained sensitive to vancomycin and linezolid. In Pseudomonas species, resistance to third generation cephalosporins, ceftazidime , was 27%, while resistance to imipenem was seen in 3 (9%) of isolates. In Proteus species, resistance to third generation cephalosporins was 90% while to imipenem resistance was 60%. Resistance to commonly prescribed quinolones was more than 70% among all the bacterial isolates.
Conclusions: Common Gram positive and Gram negative organisms responsible for infection in DFU were Staphylococcus aureus, Pseudomonas species and Proteus species. The isolates were multi-drug resistant (MDR). Resistance to antibiotics used as empiric therapy was high.