Bacterial fitness in chronic wounds appears to be mediated by the capacity for high-density growth, not virulence or biofilm functions.

While much is known about acute infection pathogenesis, the understanding of chronic infections has lagged. Here we sought to identify the genes and functions that mediate fitness of the pathogen Pseudomonas aeruginosa in chronic wound infections, and to better understand the selective environment in wounds. We found that clinical isolates from chronic human wounds were frequently defective in virulence functions and biofilm formation, and that many virulence and biofilm formation genes were not required for bacterial fitness in experimental mouse wounds.

Biofilms and Inflammation in Chronic Wounds.

Significance: The incidence, cost, morbidity, and mortality associated with non-healing of chronic skin wounds are dramatic. With the increasing numbers of people with obesity, chronic medical conditions, and an increasing life expectancy, the healthcare cost of non-healing ulcers has recently been estimated at $25 billion annually in the United States. The role played by bacterial biofilm in chronic wounds has been emphasized in recent years, particularly in the context of the prolongation of the inflammatory phase of repair

Recent Advances: Rapid high-throughput genomic approaches have revolutionized the ability to identify and quantify microbial organisms from wounds.

Cutaneous angiosarcoma clinically presenting as progressive solid facial edema in a 43-year-old male.

Cutaneous angiosarcoma of the head and neck is a rare, highly malignant neoplasm; prognosis is heavily influenced by tumor size, resectability, and stage at initial diagnosis. Most patients present with one to several erythematous to violaceous patches, plaques, or nodules. However, the clinical presentation is highly variable and leads to delayed diagnosis.

The association of psoriasiform rash with anti-tumor necrosis factor (anti-TNF) therapy in inflammatory bowel disease: a single academic center case series.

Background & Aims: Anti-tumor necrosis factors (anti-TNF) including infliximab, adalimumab and certolizumab pegol are used to treat Crohn's disease (CD) and ulcerative colitis (UC). Paradoxically, while also indicated for the treatment of psoriasis, anti-TNF therapy has been associated with development of psoriasiform lesions in IBD patients and can compel discontinuation of therapy. We aim to investigate IBD patient, clinical characteristics, and frequency for the development of and outcomes associated with anti-TNF induced psoriasiform rash.

Phevalin (aureusimine B) production by Staphylococcus aureus biofilm and impacts on human keratinocyte gene expression.

Staphylococcus aureus biofilms are associated with chronic skin infections and are orders of magnitude more resistant to antimicrobials and host responses. S. aureus contains conserved nonribosomal peptide synthetases that produce the cyclic dipeptides tyrvalin and phevalin (aureusimine A and B, respectively).

Time course study of delayed wound healing in a biofilm-challenged diabetic mouse model.

Bacterial biofilm has been shown to play a role in delaying wound healing of chronic wounds, a major medical problem that results in significant health care burden. A reproducible animal model could be very valuable for studying the mechanism and management of chronic wounds. Our previous work showed that Pseudomonas aeruginosa (PAO1) biofilm challenge on wounds in diabetic (db/db) mice significantly delayed wound healing.

Differential effects of planktonic and biofilm MRSA on human fibroblasts.

Bacteria colonizing chronic wounds often exist as biofilms, yet their role in chronic wound pathogenesis remains unclear. Staphylococcus aureus biofilms induce apoptosis in dermal keratinocytes, and given that chronic wound biofilms also colonize dermal tissue, it is important to investigate the effects of bacterial biofilms on dermal fibroblasts. The effects of a predominant wound pathogen, methicillin-resistant S.

Staphylococcus aureus Biofilm and Planktonic cultures differentially impact gene expression, mapk phosphorylation, and cytokine production in human keratinocytes.

Background: Many chronic diseases, such as non-healing wounds are characterized by prolonged inflammation and respond poorly to conventional treatment. Bacterial biofilms are a major impediment to wound healing. Persistent infection of the skin allows the formation of complex bacterial communities termed biofilm.

Quantifying the effect of pore size and surface treatment on epidermal incorporation into percutaneously implanted sphere-templated porous biomaterials in mice.

The sinus between skin and a percutaneous medical device is often a portal for infection. Epidermal integration into an optimized porous biomaterial could seal this sinus. In this study, we measured epithelial ingrowth into rods of sphere-templated porous poly(2-hydroxyethyl methacrylate) implanted percutaneously in mice.

Resident bacterial flora in the skin of C57BL/6 mice housed under SPF conditions.

Research in cutaneous biology frequently involves models that use mice housed in SPF conditions. Little information is available concerning the species of bacteria that normally inhabit the skin of these mice. The aim of this study was to characterize the bacterial skin flora of mice housed under SPF conditions.

Delayed wound healing in diabetic (db/db) mice with Pseudomonas aeruginosa biofilm challenge: a model for the study of chronic wounds.

Chronic wounds are a major clinical problem that lead to considerable morbidity and mortality. We hypothesized that an important factor in the failure of chronic wounds to heal was the presence of microbial biofilm resistant to antibiotics and protected from host defenses. A major difficulty in studying chronic wounds is the absence of suitable animal models.

Granulomatous dermatitis with pseudoxanthoma elasticum-like changes: report of a case in a patient with cystic fibrosis.

Background: There is scant literature that documents pseudoxanthoma elasticum (PXE)-like histologic changes in the setting of inflammatory skin diseases. This article documents granulomatous dermatitis with PXE-like changes in a patient with cystic fibrosis. This is the first report of its kind, to our knowledge.

Loss of viability and induction of apoptosis in human keratinocytes exposed to Staphylococcus aureus biofilms in vitro.

Bacteria colonizing chronic wounds are believed to exist as polymicrobial, biofilm communities; however, there are few studies demonstrating the role of biofilms in chronic wound pathogenesis. This study establishes a novel method for studying the effect of biofilms on the cell types involved in wound healing. Cocultures of Staphylococcus aureus biofilms and human keratinocytes (HK) were created by initially growing S.

Diagnosis of mycosis fungoides with different algorithmic approaches.

Background: Algorithmic scoring approaches for evaluating early cases of mycosis fungoides (MF) provide a degree of diagnostic standardization. At the UWMC, biopsies from clinically concerning cases for MF are individually reviewed by a panel of pathologists and an average score is assigned to each biopsy reflecting the degree of suspicion for a diagnosis of MF; however, such an approach may not be practical outside of an academic center.

Methods: 78 cases characterized in our institution, with the diagnosis confirmed by clinicopathologic correlation/clinical follow-up were evaluated with two different algorithms, based entirely on histologic evaluation (Guitart algorithm) and partial implementation of the ISCL algorithm evaluating histology, immunohistochemistry and T-cell clonality.

Methods to promote Notch signaling at the biomaterial interface and evaluation in a rafted organ culture model.

The Notch signaling pathway is a promising target for controlling cell fate choices at the biomaterial-tissue interface. Building on our previous work in developing Notch-signaling biomaterials, we evaluated various immobilization schemes for Notch ligands, and their effect on human foreskin keratinocytes. A peptide sequence derived from the Jagged-1 DSL-region and immobilized to poly(2-hydroxyethyl methacrylate) (polyHEMA) showed no bioactivity in relation to the Notch-CSL pathway.

Ultrastructural localization of integrin subunits beta4 and alpha3 within the migrating epithelial tongue of in vivo human wounds.

Subsequent to wounding, keratinocytes must quickly restore barrier function. In vitro wound models have served to elucidate mechanisms of epithelial closure and key roles for integrins alpha6beta4 and alpha3beta1. To extrapolate in vitro data to in vivo human tissues, we used ultrathin cryomicrotomy to simultaneously observe tissue ultrastructure and immunogold localization in unwounded skin and acute human cutaneous wounds.

Models for diabetic wound healing and healing into percutaneous devices.

Delayed healing of chronic ulcers in patients with diabetes and infections resulting from percutaneous medical devices (e.g., vascular access catheters) not only plays a major role in morbidity and mortality, but is a major burden to our healthcare system.

Unusual granulomatous variant of scleromyxedema.

Scleromyxedema is notable for significant morbidity and mortality. A generalized eruption of waxy papules in the absence of thyroid disease with histologic findings of mucin deposition, increased fibroblast proliferation, and fibrosis are the characteristic features of scleromyxedema. We report a case of scleromyxedema that, on histology, was associated with interstitial granuloma annulare-like features.

Keratinocyte migration, proliferation, and differentiation in chronic ulcers from patients with diabetes and normal wounds.

Epithelialization of normal acute wounds occurs by an orderly series of events whereby keratinocytes migrate, proliferate, and differentiate to restore barrier function. The keratinocytes in the epidermis of chronic ulcers fail to execute this series of events. To better understand the epithelial dynamics of chronic ulcers, we used immunohistochemistry to evaluate proliferation, differentiation, adhesion, and migration in keratinocytes along the margin of chronic ulcers from patients with diabetes mellitus.

Topical application of laminin-332 to diabetic mouse wounds.

Background: Keratinocyte migration is essential for wound healing and diabetic wound keratinocytes migrate poorly. Keratinocyte migration and anchorage appears to be mediated by laminin-332 (LM-332). Impaired diabetic wound healing may be due to defective LM-332 mediated keratinocyte migration.

Giant cell rich histiocytic dermatitis/panniculitis associated with thrombocytosis.

An unusual histiocytic dermatitis associated with a lymphoplasmacytic and histiocytic panniculitis appears to represent a previously undescribed disease process. A 56-year-old woman presented with a 5 year history of a violaceous, maculo-papular rash primarily on her legs. It began approximately 8 months before therapy for thrombocytosis.