Update of biomarkers to diagnose diabetic foot osteomyelitis: A meta-analysis and systematic review.

The aim of this study was to evaluate the diagnostic characteristics of biomarker for diabetic foot osteomyelitis (DFO). We searched PubMed, Scopus, Embase and Medline for studies who report serological markers and DFO before December 2022. Studies must include at least one of the following diagnostic parameters for biomarkers: area under the curve, sensitivities, specificities, positive predictive value, negative predictive value. Two authors evaluated quality using the Quality Assessment of Diagnostic Accuracy Studies tool. We included 19 papers. In this systematic review, there were 2854 subjects with 2134 (74.8%) of those patients being included in the meta-analysis. The most common biomarkers were erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and procalcitonin (PCT). A meta-analysis was then performed where data were evaluated with Forrest plots and receiver operating characteristic curves. The pooled sensitivity and specificity were 0.72 and 0.75 for PCT, 0.72 and 0.76 for CRP and 0.70 and 0.77 for ESR. Pooled area under the curves for ESR, CRP and PCT were 0.83, 0.77 and 0.71, respectfully. Average diagnostic odds ratios were 16.1 (range 3.6-55.4), 14.3 (range 2.7-48.7) and 6.7 (range 3.6-10.4) for ESR, CRP and PCT, respectfully. None of the biomarkers we evaluated could be rated as 'outstanding' to diagnose osteomyelitis. Based on the areas under the curve, ESR is an 'excellent' biomarker to detect osteomyelitis, and CRP and PCT are 'acceptable' biomarkers to diagnose osteomyelitis. Diagnostic odds ratios indicate that ESR, CRP and PCT are 'good' or 'very good' tools to identify osteomyelitis.

MRSA infection, re-infection and clinical outcomes in diabetic foot infections.

The aim was to investigate methicillin-resistant Staphylococcus aureus (MRSA) incidence, conversion and outcomes in diabetic foot infections (DFIs). This is a pooled patient-level analysis of combined data sets from two randomised clinical trials including 219 patients admitted to the hospital with moderate or severe DFIs. Intraoperative bone and tissue cultures identified bacterial pathogens. We identified pathogens at index infections and subsequent re-infections. We identified MRSA conversion (MSSA to MRSA) in re-infections. MRSA incidence in index infections was 10.5%, with no difference between soft tissue infections (STIs) and osteomyelitis (OM). MRSA conversion occurred in 7.7% of the re-infections in patients who initially had MSSA in their cultures. Patients with re-infection were 2.2 times more likely to have MRSA compared to the first infection (10.5% vs. 25.8%, relative risk [RR] = 2.2, p = 0.001). Patients with MRSA had longer antibiotic treatment during the 1-year follow-up, compared to other pathogens (other 49.8 ± 34.7 days, MRSA 65.3 ± 41.5 days, p = 0.04). Furthermore, there were no differences in healing, time to heal, length of stay, re-infection, amputation, re-ulceration, re-admission, surgery after discharge and amputation after discharge compared to other pathogens. The incidence of MRSA at the index was 10.5% with no difference in STI and OM. MRSA incidence was 25.8% in re-infections. The RR of having MRSA was 2.2 times higher in re-infections. Patients with MRSA used more antibiotics during the 1-year follow-up. Furthermore, there were no differences in clinical outcomes compared to other bacterial pathogens.

Foot abscesses with no accompanying wound: clinical presentation and pathogens.

INTRODUCTION: Acute bacterial infections of the skin and soft tissue are common and often pose serious complications, most commonly caused by Streptococcus species and Staphylococcus aureus. OBJECTIVE: The authors report clinical presentation and pathogens in patients with a foot abscess and no wound. METHODS: The authors retrospectively evaluated the demographics, clinical presentation, and microbiology from 20 patient records. RESULTS: Twenty patients were identified. Fifteen were male (75%), and 10 patients (50%) had DM. Patients presented to the hospital 7.8 ± 4.8 days after onset of symptoms and underwent surgery 2.0 ± 0.9 days from admission. Patients underwent 2.4 ± 1.0 surgeries while admitted. Patients with DM presented with significantly higher erythrocyte sedimentation rate than patients without DM (66.6 ± 46.1 vs 43.3 ± 26.2; P = .02). There were no polymicrobial infections based on deep intraoperative tissue cultures. Seven patients had methicillin-sensitive S aureus (35%), 4 had Streptococcus agalactiae (20%), 3 had methicillin-resistant S aureus (15%), 1 had Streptococcus pyogenes (5%), 1 had Escherichia coli (5%), 1 had Streptococcus dysgalactiae (5%), 1 had an unidentified Streptococcus species (5%), and 2 had no growth (10%). CONCLUSION: Patients with foot abscess and no wounds had single-pathogen infections, predominantly Staphylococcus and Streptococcus.