Microbiological and clinical characteristics of diabetic foot infections in northern India

Abstract

Introduction: India has the largest diabetic population of 50.8 million that could reach an epidemic proportion by 2030. Diabetic foot infection is one of the dreaded complications of diabetes. Only a few studies that focus on patterns of diabetic foot infection in our region, where diabetic foot care is inadequate, are available. This study evaluated microbial and clinical characteristics of diabetic foot infections that will be helpful in taking appropriate measures for their management. Methodology: In this prospective study conducted during 2008-2009, sixty-two diabetic foot patients underwent detailed history, clinical examination, and laboratory investigations including parameters of systemic infections. Microbial culture and sensitivity were performed at the time of presentation. Results: Among 62 cases, 43.5% had mono-microbial infection, 35.5% had poly-microbial infections, and 21% had sterile culture. Among 82 bacteria isolated, 68% were Gram negative and 32% were Gram positive. Leukocyte counts were higher (16928±9642 versus 14593±6687 cells/mm 3 ) and haemoglobin (7.9±2.4 versus 9.2±2.2 mg/dl) lower in poly-microbial compared to mono-microbial infections. Haemoglobin counts were lower and leukocyte counts higher in Gram-negative compared to Gram-positive infections. Patients with sterile cultures also had clinical evidence of persistent infection. Escherichia coli were the most common isolate and piperacillin/tazobactam showed highest sensitivity. Conclusions: Gram-negative bacteria were most prevalent in diabetic foot infection. It is not uncommon to have culture reports negative despite clinical evidence of infection. This study suggests that piperacillin/tazobactam should be the treatment of choice on an empirical basis prior to a definitive bacteriological study and in cases with negative culture reports.

Culture-Based Screening of Aerobic Microbiome in Diabetic Foot Subjects and Developing Non-healing Ulcers

“…Earlier studies have shown that most diabetic foot infections are polymicrobial with a predominance of Gram-positive cocci especially S. aureus , and Streptococci (Sapico et al, 1984; Jones et al, 1985). However, recent studies indicate the dominance of Gram-negative pathogens in the monomicrobial state, particularly members of family Enterobacteriace and Pseudomonas (Tiwari et al, 2011; Turhan et al, 2013). The prolonged course of antimicrobials for uninfected lesion or healed wounds, long hospital stay, and surgical measures may predispose patients to colonization and infection with drug-resistant pathogens and associated adverse outcomes.…”

Significance of Surgical Intervention in the Management of Diabetic Foot Infections

“…33,39,40,42 In contrast, some other studies have also reported a higher prevalence of mono-microbial infection in diabetic foot. 43,47 In one study, 44 it was noticed that S. aureus and Pseudomonas aeruginosa were the most common causes of diabetic foot infections. In a North Indian study of DFUs, it was found that gram-negative aerobes were the most frequently isolated (51.4%), followed by grampositive aerobes and anaerobes.…”

“…33 Fincke et al found large variations in the antibiotic regimens used to treat patients with diabetic foot infections. 47 47 …”

Role of anaerobes in polymicrobial communities and biofilms complicating diabetic foot ulcers

“…An additional study conducted by Tiwari and colleagues on 62 DFUs found Escherichia coli to be the most common isolated species followed by Staphylococcus aureus . Microbiological specimens were obtained from tissue biopsies and cultured under aerobic conditions.…”