Staphylococcus aureus is a major human pathogen that causes a wide range of clinical infections. It is a leading cause of bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections. This review comprehensively covers the epidemiology, pathophysiology, clinical manifestations, and management of each of these clinical entities. The past 2 decades have witnessed two clear shifts in the epidemiology of S. aureus infections: first, a growing number of health care-associated infections, particularly seen in infective endocarditis and prosthetic device infections, and second, an epidemic of community-associated skin and soft tissue infections driven by strains with certain virulence factors and resistance to β-lactam antibiotics. In reviewing the literature to support management strategies for these clinical manifestations, we also highlight the paucity of high-quality evidence for many key clinical questions.

Staphylococcus aureus Infections: Epidemiology, Pathophysiology, Clinical Manifestations, and Management

Foot infections are a common and serious problem in persons with diabetes Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations) This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy) Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation) Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures Employing multidisciplinary foot teams improves outcomes Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs

2012 Infectious Diseases Society of America Clinical Practice Guideline for the Diagnosis and Treatment of Diabetic Foot Infections

Benjamin A. Lipsky, Anthony R. Berendt, H. Gunner Deery, John M. Embil, Warren S. Joseph, Adolf W. Karchmer, Jack L. LeFrock, Daniel P. Lew, Jon T. Mader, Carl Norden, and James S. Tan Medical Service, Veterans Affairs Puget Sound Health Care System, and Division of General Internal Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington; Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford, United Kingdom; Northern Michigan Infectious Diseases, Petoskey, Michigan; Section of Infectious Diseases, Department of Medicine, University of Manitoba, Winnipeg, Manitoba; Section of Podiatry, Department of Primary Care, Veterans Affairs Medical Center, Coatesville, Pennsylvania; Division of Infectious Diseases, Department of Medicine, Harvard Medical School, and Beth Israel Deaconess Medical Center, Boston, Massachusetts; Dimensional Dosing Systems, Sarasota, Florida; Department of Medicine, Service of Infectious Diseases, University of Geneva Hospitals, Geneva, Switzerland; Department of Internal Medicine, The Marine Biomedical Institute, and Department of Orthopaedics and Rehabilitation, University of Texas Medical Branch, Galveston, Texas; Department of Medicine, New Jersey School of Medicine and Dentistry, and Cooper Hospital, Camden, New Jersey; and Department of Internal Medicine, Summa Health System, and Northeastern Ohio Universities College of Medicine, Akron, Ohio

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Diagnosis and Treatment of Diabetic Foot Infections

Diabetic foot infections are a frequent clinical problem. About 50% of diabetic foot infections who have foot amputations die within five years. Properly managed most can be cured, but many patients needlessly undergo amputations because of improper diagnostic and therapeutic approaches. This approach along with vascular assessment help clinical decisions about which patients to hospitalize, which to send for imaging procedures or for whom to recommend surgical interventions. This paper reviewed the natural history of the diabetic foot and assessed the surgical impact of the Infectious Diseases Society of America clinical practice guideline- based care of diabetic foot infections.

The Diabetic Foot

The prevalence of diabetes mellitus is growing at epidemic proportions in the United States and worldwide. Most alarming is the steady increase in type 2 diabetes, especially among young and obese people. An estimated 7% of the US population has diabetes, and because of the increased longevity of this population, diabetes-associated complications are expected to rise in prevalence. Foot ulcerations, infections, Charcot neuroarthropathy, and peripheral arterial disease frequently result in gangrene and lower limb amputation. Consequently, foot disorders are leading causes of hospitalization for persons with diabetes and account for billion-dollar expenditures annually in the US. Although not all foot complications can be prevented, dramatic reductions in frequency have been achieved by taking a multidisciplinary approach to patient management. Using this concept, the authors present a clinical practice guideline for diabetic foot disorders based on currently available evidence, committee consensus, and current clinical practice. The pathophysiology and treatment of diabetic foot ulcers, infections, and the diabetic Charcot foot are reviewed. While these guidelines cannot and should not dictate the care of all affected patients, they provide evidence-based guidance for general patterns of practice. If these concepts are embraced and incorporated into patient management protocols, a major reduction in diabetic limb amputations is certainly an attainable goal.

Diabetic Foot Disorders: A Clinical Practice Guideline (2006 Revision)

Foot infections in diabetic patients are predominantly caused by gram-positive cocci, many of which are now antibiotic resistant. Because linezolid is active against these pathogens, we compared the efficacy and safety of intravenous and oral formulations with that of intravenous ampicillin-sulbactam and intravenous and oral amoxicillin-clavulanate given for 7-28 days in a randomized, open-label, multicenter study of all types of foot infection in diabetic patients (ratio of linezolid to comparator drug recipients, 2:1). Among 371 patients, the clinical cure rates associated with linezolid and the comparators were statistically equivalent overall (81% vs. 71%, respectively) but were significantly higher for linezolid-treated patients with infected foot ulcers (81% vs. 68%; P=.018) and for patients without osteomyelitis (87% vs. 72%; P=.003). Cure rates were comparable for inpatients and outpatients and for both oral and intravenous formulations. Drug-related adverse events were significantly more common in the linezolid group, but they were generally mild and reversible. Linezolid was at least as effective as aminopenicillin/beta-lactamase inhibitors for treating foot infections in diabetic patients.

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Treating Foot Infections in Diabetic Patients: A Randomized, Multicenter, Open-Label Trial of Linezolid versus Ampicillin-Sulbactam/Amoxicillin-Clavulanate

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Carl Norden

Papers

Diagnosis and Treatment of Diabetic Foot Infections

Treating Foot Infections in Diabetic Patients: A Randomized, Multicenter, Open-Label Trial of Linezolid versus Ampicillin-Sulbactam/Amoxicillin-Clavulanate

Diagnosis and treatment of diabetic foot infections

Clinical Features and Outcomes of Bacteremia Caused by Enterococcus casseliflavus and Enterococcus gallinarum: Analysis of 56 Cases