Understanding the microbiome of diabetic foot osteomyelitis: insights from molecular and microscopic approaches

Abbas

et al. 2020

Background Securing an early accurate diagnosis of diabetic foot infections and assessment of their severity are of paramount importance since these infections can cause great morbidity and potentially mortality and present formidable challenges in surgical and antimicrobial treatment. Methods In June 2018, we searched the literature using PuEbMed and EMBASE for published studies on the diagnosis of diabetic foot infection. On the basis of predetermined criteria, we reviewed prospective controlled, as well as noncontrolled, studies in any language, seeking translations for those not in English. We then developed evidence statements on the basis of the included papers. Results From the 4242 records screened, we selected 35 papers that met our inclusion criteria. The quality of all but one of the evidence statements was low because of the weak methodology of nearly all of the studies. The available data suggest that diagnosing diabetic foot infections on the basis of clinical signs and symptoms and classified according to the International Working Group of the Diabetic Foot scheme correlates with the patient's likelihood of ulcer healing, of lower extremity amputation, and risk of death. Elevated levels of selected serum inflammatory markers are supportive, but not diagnostic, of soft tissue or bone infection. In patients with suspected diabetic foot osteomyelitis, both a positive probe‐to‐bone test and an elevated erythrocyte sedimentation rate are strongly associated with its presence. Culturing tissue samples of soft tissues or bone, when care is taken to avoid contamination, provides more accurate microbiological information than culturing superficial (swab) samples. Plain X‐ray remains the first‐line imaging examination when there is suspicion of diabetic foot osteomyelitis, but advanced imaging methods help in cases when either the diagnosis or the localization of infection is uncertain. Conclusion The results of this first reported systematic review on the diagnosis of diabetic foot infections provide some guidance for clinicians, but there is a need for more prospective controlled studies of high quality.

Section: Discussionmentioning

confidence: 99%

Diagnosis of infection in the foot in diabetes: a systematic review

Abbas

et al. 2020

“…Although Corynebacterium spp. and obligate anaerobes appear to be more prevalent using sequencing techniques, their pathogenic role as part of a polymicrobial infection is unclear . Overall, there is generally good agreement between molecular sequencing and conventional culture methods regarding the most clinically relevant pathogens identified .…”

Section: Microbiologymentioning

confidence: 99%

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

Abbas

et al. 2020

521

729

The International Working Group on the Diabetic Foot (IWGDF) has published evidence‐based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

“…Both IDSA and IWGDF do not recommend performing a bone biopsy in every patient with a suspicion of DFO but only when doubt persists after imaging assessment and/or when identification of the pathogens is of importance especially after failure of a first‐line antibiotic treatment . Independent‐culture methods such as DNA‐based techniques have shown their superiority over classical methods in terms of quantity and diversity of the identified bacterial strains but have not yet shown any clinical benefit for the management including the antibiotic treatment of these patients …”

Section: Resultsmentioning

confidence: 99%

“…3,4 Independentculture methods such as DNA-based techniques have shown their superiority over classical methods in terms of quantity and diversity of the identified bacterial strains but have not yet shown any clinical benefit for the management including the antibiotic treatment of these patients. 30 3 | CONCLUSIONS DFO is highly prevalent in patients presenting with DFI and its defi-…”

Section: Bone Biopsymentioning

confidence: 99%

Diagnosing diabetic foot osteomyelitis

Asten

et al. 2020

Bone involvement during an infection of the diabetic foot represents a serious complication associated with a high risk of amputation, prolonged antibiotic treatment and hospitalization. Diabetic foot osteomyelitis (DFOs) require a multidisciplinary approach given the usual complexity of these situations. DFO should be suspected in most cases especially in the most severe forms of soft tissue diabetic foot infections (DFIs) where the prevalence of bone infection may be up to 60%. Suspicion is based on clinical signs in particular a positive probe‐to‐bone (PTB) test, elevated inflammatory biomarkers especially erythrocyte sedimentation rate and abnormal imaging assessment using plain X‐ray as a first‐line choice. The combination of PTB test with plain X‐ray has proven effective in the diagnosis of DFO. The confirmation (definite) diagnosis of DFO is based on the results of a bone sample examination obtained by either surgical or percutaneous biopsy. Sophisticated imaging examinations such as Magnetic Resonance Imaging (MRI) and nuclear imaging techniques are useful where doubt persists after first‐line imaging assessment. These techniques may also help localize the bone infection site and increase the diagnostic performance of percutaneous bone biopsy. The quality of the microbiological documentation of DFO is likely to improve the adequacy of the antimicrobial therapy especially when medical (ie, no surgical resection of the infected bone tissues) is considered. The use of new (molecular) techniques for the identification of the bone pathogens have not yet proven superiority on classic cultural techniques for the management of such patients.