Clinical presentation of group B Streptococcus-infected diabetic foot ulcers

Abstract

Objective: Group B Streptococcus (GBS) is a common pathogen in diabetic foot ulcers (DFUs), where it has been found to result in higher rates of soft tissue infection and amputation despite appropriate treatment. In this study, we aim to investigate clinical characteristics and prognosis of GBS DFU infections, especially those with tenosynovial involvement. We hypothesise that GBS-infected DFUs with tenosynovial involvement leads to an increased number of recurrent infections and unexpected returns to the operating room. Method: Data were retrospectively collected from GBS-infected DFU patients surgically treated by an orthopaedic foot and ankle surgeon over a four-year period. Demographics, comorbidities, initial laboratory values and culture results from infected bone samples were recorded. Clinical outcome was assessed by recurrent infection and unplanned reoperation(s) within 3 months following the initial surgery. Results: In total, 72 patients were treated for GBS-infected DFUs. Intra-operative culture of infected bone identified GBS in 16 patients (22.2%). Significantly more black patients (p=0.017) were afflicted by GBS DFUs. Patients with GBS DFUs had higher initial haemoglobin A1C levels (p=0.019), and those with tenosynovial involvement were likely to require reoperation (p=0.036) and had a greater total number of surgeries (p=0.015) than those without. Conclusion: GBS-infected DFUs are more common in black patients and those with elevated haemoglobin A1Cs. GBS infections with tenosynovial involvement are particularly destructive and require aggressive treatment by surgeons.