Diabetic foot infection and osteomyelitis. Are deep-tissue cultures necessary?

Prevalence of multidrug-resistant bacterial infections in diabetic foot ulcers: A meta-analysis

Multidrug-resistant (MDR) bacterial infections have become increasingly common in recent years due to the increased prevalence of diabetic foot ulcers (DFUs). We carried out a meta-analysis aimed at investigating the prevalence of MDR bacteria isolated from DFUs and analysing the risk factors for MDR bacterial infection in patients with DFUs. The PubMed/Medline, Web of Science, Embase, Cochrane Library, Ovid, Scopus, and ProQuest databases were searched for studies published up to November 2023 on the clinical outcomes of MDR bacteria in DFUs. The main outcome was the prevalence of MDR bacteria in DFUs. A total of 21 studies were included, representing 4885 patients from which 2633 MDR bacterial isolates were obtained. The prevalence of MDR bacteria in DFUs was 50.86% (95% confidence interval (CI): 41.92%-59.78%). The prevalence of MDR gram-positive bacteria (GPB) in DFUs was 19.81% (95% CI: 14.35%-25.91%), and the prevalence of MDR gram-negative bacteria (GNB) in DFUs was 32.84% (95% CI: 26.40%-39.62%). MDR Staphylococcus aureus (12.13% (95% CI: 8.79%-15.91%)) and MDR Enterococcus spp. (3.33% (95% CI: 1.92%-5.07%)) were the main MDR-GPB in DFUs. MDR Escherichia coli, MDR Pseudomonas aeruginosa, MDR Enterobacter spp., MDR Klebsiella pneumoniae, and MDR Proteus mirabilis were the main MDR-GNB in DFUs. The prevalence rates were 6.93% (95% CI: 5.15%-8.95%), 6.01% (95% CI: 4.03%-8.33%), 3.59% (95% CI: 0.42%-9.30%), 3.50% (95% CI: 2.31%-4.91%), and 3.27% (95% CI: 1.74%-5.21%), respectively. The clinical variables of diabetic foot ulcer patients infected with MDR bacteria and non-MDR bacteria in the included studies were analysed. The results showed that peripheral vascular disease, peripheral neuropathy, nephropathy, osteomyelitis, Wagner's grade, previous hospitalization and previous use of antibacterial drugs were significantly different between the MDR bacterial group and the non-MDR bacterial group. We concluded that there is a high prevalence of MDR bacterial infections in DFUs. The prevalence of MDR-GNB was greater than that of MDR-GPB in DFUs. MDR S. aureus was the main MDR-GPB in DFUs, and MDR E. coli was the main MDR-GNB in DFUs. Our study also indicated that peripheral vascular disease, peripheral neuropathy, nephropathy, osteomyelitis, Wagner's grade, previous hospitalization, and previous use of antibacterial drugs were associated with MDR bacterial infections in patients with DFUs.

Distribution of Causative Microorganisms in Diabetic Foot Infections: A Ten-Year Retrospective Study in a Tertiary Care Hospital in Central Malaysia

Diabetes mellitus is a global pandemic, especially in Southeast Asia. Diabetic foot infection (DFI) is a common complication of this condition and causes significant morbidity and mortality in those affected. There is a lack of locally published data on the types of microorganisms and empirical antibiotics being prescribed. This paper highlights the importance of local microorganism culture and antibiotic prescription trends among diabetic foot patients in a tertiary care hospital in central Malaysia. This is a retrospective, cross-sectional study of data taken from January 2010 to December 2019 among 434 patients admitted with diabetic foot infections (DFIs) using the Wagner classification. Patients between the ages of 58 and 68 years old had the highest rate of infection. Pseudomonas Aeruginosa, Proteus spp., and Proteus mirabilis appeared to be the most isolated Gram-negative microorganisms, and Staphylococcus aureus, Streptococcus agalactiae, and MRSA appeared to be the most common Gram-positive microorganisms. The most common empirical antibiotics prescribed were ampicillin/sulbactam, followed by ciprofloxacin and ceftazidime, and the most common therapeutic antibiotics prescribed were ampicillin/sulbactam, ciprofloxacin, and cefuroxime. This study could be immensely pertinent in facilitating future empirical therapy guidelines for treating diabetic foot infections.

Necrotizing Skin and Soft Tissue Infection Due to Syncephalastrum Species and Fusarium solani Species Complex Following Open Tibia Fracture

Fungal necrotizing skin and soft tissue infection (NSSTI) represents a rare clinical entity. An extremely rare case of NSSTI, following an open tibia fracture in a 36-year-old male caused by both Syncephalastrum spp. and Fusarium solani species complex (SC) is presented. The infection was diagnosed through direct microscopy, cultures and histology. The disease had a long course. The patient underwent a total of seven consecutive surgical debridements, while proper and timely antifungal treatment was initiated and included liposomal amphotericin B and voriconazole. He gradually recovered and 4 years later he is completely functioning and healthy. Invasive fungal infections are well-documented causes of high morbidity and mortality in immunocompromised individuals, whereas in immunocompetent hosts, trauma-related fungal infections have also been reported. It is of note that Syncephalastrum spp. has very rarely been identified to cause infection in immunocompromised or immunocompetent hosts, whereas Fusarium spp. has rarely been involved in skin necrotic lesions in non-immunocompromised individuals. A high suspicion index, especially in necrotic lesions in trauma patients, is pivotal for early diagnosis, which may lead to lower mortality as well as lower amputation rates. Definite diagnosis through microscopy, histology and/or cultures are of paramount importance, whereas PCR testing may also be extremely useful.

Surgical Treatment of Diabetic Foot and Ankle Osteomyelitis

A review of the literature regarding the evaluation and management of osteomyelitis and discussion on clinical, radiographic, laboratory, and pathologic findings with both acute and chronic cases is presented. Cases illustrate the complexities that can typically present at an academic setting, which often require a stepwise approach and interdisciplinary collaboration. Surgical pearls and ancillary treatment of osteomyelitis highlight the technical challenges and surgeons' preferences.

Risk Factors for Multidrug-Resistant Organisms Infection in Diabetic Foot Ulcer

Objective

The aim of this study is to analyze the microbiological characteristics of diabetic foot ulcer (DFU) and drug resistance of multidrug-resistant organisms (MDROs) and to reveal the potential risk factors for MDROs. This provides a basis for early empiric antibiotic treatment.

Methods

This study included 348 patients with diabetic foot ulcer in Chu Hsien-I Memorial Hospital & Metabolic Disease Hospital of Tianjin Medical University between May 2020 and November 2021. A total of 475 strains of bacteria were cultured, among which 240 strains were multidrug-resistant bacteria, accounting for 51%. Binary logistic regression was used to analyze risk factors. First, univariate analysis was used to calculate the p value of variables, and then multivariate analysis was conducted for variables with p < 0.1 to analyze independent risk factors. Risk factors with p < 0.05 in multivariable analysis were considered as independent risk factors. The strength of the association was represented by odds ratio and 95% confidence interval.

Results

Univariable logistic regression analysis demonstrated that previous hospitalization, previous antibiotic therapy, ulcer size >4cm², surgical therapy, D-dimer, and CRP were associated with MDRO infection in patients with DFU. Multivariate logistic regression analysis demonstrated that previous hospitalization (OR = 1.91; 95% CI = 1.11–3.28; p = 0.02), ulcer size >4cm² (OR = 1.68; 95% CI = 1.03–2.76; p = 0.04), surgical therapy (OR = 2.14; 95% CI = 1.03–4.47; p = 0.04), and CRP (OR = 1.01; 95% CI = 1.00–1.01; p = 0.03) were independent risk factors for MDROs infection in diabetic foot patients. Drug resistance analysis may indicate that the proportion and drug resistance rate of Acinetobacter baumannii in Tianjin, China, have changed.

Conclusion

Previous hospitalization, ulcer size >4cm², surgical therapy and CRP were independent risk factors for MDROs infection in diabetic foot patients. Identifying these risk factors can help us identify the high-risk patients of diabetic foot with MDRO infection early. More attention to high-risk patients and more aggressive isolation precautions may reduce the incidence of MDRO infection in diabetic foot patients.