Joseph Jones: infection with flesh eating bacteria

Vibrio vulnificus, an Underestimated Zoonotic Pathogen

V. vulnificus, continues being an underestimated yet lethal zoonotic pathogen. In this chapter, we provide a comprehensive review of numerous aspects of the biology, epidemiology, and virulence mechanisms of this poorly understood pathogen. We will emphasize the widespread role of horizontal gene transfer in V. vulnificus specifically virulence plasmids and draw parallels from aquaculture farms to human health. By placing current findings in the context of climate change, we will also contend that fish farms act as evolutionary drivers that accelerate species evolution and the emergence of new virulent groups. Overall, we suggest that on-farm control measures should be adopted both to protect animals from Vibriosis, and also as a public health measure to prevent the emergence of new zoonotic groups.

Necrotizing fasciitis a review

Necrotizing fasciitis is an uncommon, rapidly progressive, often aggressive bacterial infection that causes extensive necrosis of the subcutaneous tissue and fascia, relatively sparing the muscle and skin tissues. Rapid diagnosis of the disease is mandatory because the delay in initiation of aggressive treatment negatively influences the outcome. Specific clinical signs may not be always present, which makes an accurate and timely diagnosis difficult. Based on the literature, this article presents a review of the historical background, etiology, pathophysiology, clinical findings, diagnostic strategies, treatment and prognosis of the disease.

Decellularization of a Fasciocutaneous Flap for Use as a Perfusable Scaffold

BACKGROUND

The aim of the current study was to determine whether a rat fasciocutaneous flap could be decellularized using detergent perfusion and/or agitation methods while preserving the integrity of the extracellular matrix and circulatory networks.

METHODS

Superficial inferior epigastric arterial flaps of 50 rats were randomly divided into the following 5 groups: (1) normal; (2) agitation in sodium dodecyl sulfate (SDS) for 72 hours (72h-AG); (3) perfusion and agitation with SDS for 12 hours (12h-PE-AG); (4) perfusion and agitation with SDS for 24 hours (24h-PE-AG); and (5) perfusion and agitation with SDS for 72 hours (72h-PE-AG). These flaps were evaluated by gross morphology, histology, integrity of the microcirculatory networks, and DNA quantification.

RESULTS

The DNA content of the normal flap was 1.53 μg/mg. The decellularized flaps had significantly reduced DNA contents: 72h-AG (0.55 μg/mg), 12h-PE-AG (0.52 μg/mg), 24h-PE-AG (0.23 μg/mg), and 72h-PE-AG (0.17 μg/mg). The DNA contents in both the 24h-PE-AG and 72h-PE-AG groups were significantly less than that of 72h-AG and 12h-PE-AG groups. These findings were confirmed by histology and gross morphology. The integrity of the extracellular matrix and vascular system was preserved as measured by collagen and elastin stains in the 4 decellularized groups. Despite the histological appearance of vessel integrity, none of the flaps maintained physiologic vascular integrity by closed-loop circulation.

CONCLUSIONS

A combination of perfusion and agitation for 24 hours or longer effectively decellularized the fasciocutaneous portion of composite tissue flaps and removed DNA content from the flap in our rat model with well-preserved vascular structure. This combined technique was superior to agitation alone. However, closed-loop circulation could not be preserved after decellularization with perfusion and/or agitation methods.

Bromine, bear-claw scratch fasciotomies, and the Eagle effect: management of group A streptococcal necrotising fasciitis and its association with trauma

Necrotising fasciitis is a rare, but potentially fatal, soft-tissue infection. Historical depictions of the disease have been described since classical times and were mainly recorded in wartime reports of battle injuries. Although several different species of bacteria can cause necrotising fasciitis, perhaps the most widely known is group A streptococcus (GAS). Infection control, early surgical debridement, and antibiotic therapy are now the central tenets of the clinical management of necrotising fasciitis; these treatment approaches all originate from those used in wars in the past 150 years. We review reports from the 19th century, early 20th century, and mid-20th century onwards to show how the management of necrotising fasciitis has progressed in parallel with prevailing scientific thought and medical practice. Historically, necrotising fasciitis has often, but not exclusively, been associated with penetrating trauma. However, along with a worldwide increase in invasive GAS disease, recent reports have cited cases of necrotising fasciitis following non-combat-related injuries or in the absence of antecedent events. We also investigate the specific association between GAS necrotising fasciitis and trauma. In the 21st century, molecular biology has improved our understanding of GAS pathogenesis, but has not yet affected attributable mortality.

A fatal case of multidrug resistant acinetobacter necrotizing fasciitis: the changing scary face of nosocomial infection

Necrotizing fasciitis is an uncommon soft-tissue infection, associated with high morbidity and mortality. Early recognition and treatment are crucial for survival. Acinetobacter baumannii is rarely associated with necrotizing fasciitis. Wound infections due to A. baumannii have been described in association with severe trauma in soldiers. There are only sporadic reports of monomicrobial A. baumannii necrotizing fasciitis. We report a unique case of monomicrobial necrotizing fasciitis caused by multidrug resistant (MDR) A. baumannii, in absence of any preceding trauma, surgery, or any obvious breech in the continuity of skin or mucosa. A 48-year-old woman with history of HIV, asthma, hypertension, and tobacco and excocaine use presented with acute respiratory failure requiring mechanical ventilation. She was treated for pneumonia for 7 days and was successfully extubated. All septic work-up was negative. Two days later, she developed rapidly spreading nonblanching edema with bleb formation at the lateral aspect of right thigh. Emergent extensive debridement and fasciotomy were performed. Operative findings and histopathology were consistent with necrotizing fasciitis. Despite extensive debridement, she succumbed to septic shock in the next few hours. Blood, wound, and tissue cultures grew A. baumannii, sensitive only to amikacin and polymyxin. Histopathology was consistent with necrotizing fasciitis.

Continuous renal replacement therapy as a supportive treatment for acute pediatric necrotizing fasciitis

Acute necrotizing fasciitis (NF) in children is a dangerous illness characterized by progressive necrosis of the skin and subcutaneous tissue. The present study summarizes our recent experience with the treatment of pediatric patients with severe NF. Between 2000 and 2009, eight children suffering from NF were admitted to our department. Four of the children received an active treatment strategy including continuous renal replacement therapy (CRRT), radical debridement, and broad-spectrum antibiotics. Another four children presented at a late stage of illness, and did not complete treatment. Clinical data for these two patient groups were retrospectively analyzed. The four patients that completed CRRT, radical debridement, and a course of broad-spectrum antibiotics were cured without any significant residual morbidity. The other four infants died shortly after admission. Early diagnosis, timely debridement, and aggressive use of broad-spectrum antibiotics are key factors for achieving a satisfactory outcome for cases of acute NF. Early intervention with CRRT to prevent septic shock may also improve patient outcome.

Necrotizing skin and soft tissue infections

Necrotizing skin and soft tissue infections are severe bacterial infections resulting in rapid and life-threatening soft tissue destruction and necrosis along soft tissue planes.

Management of massive soft tissue defects: The use of INTEGRA® artificial skin after necrotizing soft tissue infection of the chest

Necrotizing soft tissue infection, such as necrotizing fasciitis, is a group of highly lethal infections especially when the chest is involved due to increased risk of pulmonary complications. Because aggressive radical debridement of all poorly perfused tissue is required, patients frequently suffer from massive skin defects, which often requires autograft skin grafting or myocutaneous flaps. However, options are limited in patients with limited autograft donor availability, or questionable underlying wound bed viability, such as in scleroderma. Here, we report the case of a 49 year old female with scleroderma who suffered from a necrotizing soft tissue infection of the chest extending to her right upper arm, underwent multiple radical debridements, and reconstruction of the consequent massive chest wall defect with INTEGRA® bilaminar dermal regeneration template. This approach required a thinner skin graft without flaps, allowed for the inherently diseased donor site to heal adequately, and avoided major infections and wound complications. This report highlights an important management option for this challenging disease.

NECROTISING FASCIITIS AND MYOSITIS THAT ORIGINATED FROM GASTROINTESTINAL BACTERIAL INFECTION: TWO FATAL CASES

We present two cases of aggressive myofasciitis after gastrointestinal infections. The first patient developed necrosis of the legs over 5 days and he died on the 20th day. Vibrio vulnificus was cultured. The second patient developed bullae on his thigh and he died the next day. Streptococcus pyogenes was cultured.

Management of facial necrotizing fasciitis

Necrotizing fasciitis is a progressive, life-threatening, bacterial infection of the skin, the subcutaneous tissue and the underlying fascia, in most cases caused by ss-hemolytic group A streptococcus. Only early diagnosis and aggressive therapy including broad spectrum antibiotics and surgical intervention can avoid systemic toxicity with a high mortality rate. This uncommon disease generally occurs in the lower extremities and trunk, and only rarely affects the head and neck region. When located in the face necrotizing fasciitis is associated with severe cosmetic and functional restrictions due to the invasive infection and often to the necessary surgical treatment. Generally surgical intervention cannot be performed in the face as aggressively as in the extremities and trunk, since a lot of vital structures are found in a relatively small area. In the following article, we present the successful diagnostic and therapeutic management of an isolated facial necrotizing fasciitis as a consequence of a nasal bone fracture with a minor dermal cut.

Caloric requirements in patients with necrotizing fasciitis

Patients with necrotizing fasciitis (NF) and other soft tissue infections are often treated in burn centers due to the extent of wound care and surgical intervention needed. Sepsis and surgery increase metabolic needs and may limit oral intake and necessitate enteral (TEN) or parenteral (TPN) nutrition. We reviewed the records of patients admitted with necrotizing fasciitis or surgical soft tissue infections from January 1993 to June 1998 who had indirect calorimetry (IC) measurements performed. Records were also reviewed for surgical/medical management and nutritional intervention. Twenty-six patients were admitted with 17 of these having IC measurements (133 total IC measurements). The IC group had more surgeries (mean 4.9 versus 2.7) and 82% required mechanical ventilation (mean 17.9 days). Energy expenditure showed a moderate but significant increase in energy needs (mean 23.8 kcal/kg/day, 124% BEE) with large variations (10.7-42.4 kcal/kg/day, 60%-199% BEE) in individual energy requirements. Caloric intake averaged 73% of needs based on IC (range 53%-104%). Nearly all patients (94%) required TEN (82%) and/or TPN (41%) nutrition for a mean of 24 days (range 1-68 days). NF presents a broad range of metabolic and surgical needs. Our data indicates patients with NF have increased energy requirements and suggests provision of calories at 124% basal or 25 kcal/kg actual wt/d; but due to the large individual variation, routine assessment using IC is recommended. Clinicians need to recognize the likely need for nutritional support and possibly lengthy clinical course for these patients.

Cryptococcal myositis and vasculitis: an unusual necrotizing soft tissue infection

BACKGROUND

Cryptococcus neoformans var. neoformans is an opportunistic yeast that typically infects immunocompromised patients.

METHODS

A case report and review of the pertinent English-language literature are presented.

RESULTS

Necrotizing vasculitis associated with cryptococcal invasion was identified in 1986. Until now, only 24 cases of cryptococcal cellulitis have been reported, including one case of cryptococcal necrotizing fasciitis and one case of necrotizing vasculitis. We report an unusual case of occult disseminated cryptococcosis presenting as necrotizing cellulitis, fasciitis, and myositis.

CONCLUSIONS

Cryptococcal soft tissue infection serves as a marker of disseminated cryptococcosis in immunocompromised hosts. Owing to its rarity as a cause of soft tissue infections, diagnosis is difficult and mortality is high.

Necrotising fasciitis: a new management algorithm based on clinical classification

Necrotising fasciitis is a rare infection of the subcutaneous tissues. If untreated, it is invariably fatal, and thus a high index of suspicion for the diagnosis is required. The disease's manifestation can range from a fulminant presentation to a subtle and insidious development. The priority in every case is to proceed to radical surgical debridement. On review of the literature and based on our clinical experience, we propose a new classification based on clinical presentation and suggest an algorithm to facilitate the management of this devastating condition. Increasing awareness should be given to the management of the large wounds resulting from the surgical debridement of necrotising fasciitis.

Necrotizing Fasciitis: A Fourteen-Year Retrospective Study of 163 Consecutive Patients

This review was prompted by continued public and professional interest of necrotizing fasciitis as well as worldwide increases in the incidence of streptococcal invasive infections. Our objective was to outline the clinical course of necrotizing fasciitis and delineate factors relating to mortality among 163 diagnosed patients. Over 14 years patients diagnosed with necrotizing fasciitis were reviewed for patient history, comorbid conditions, and progression of clinical course. A logistic regression model was used to identify factors increasing mortality risk among necrotizing fasciitis patients. Nearly 17 per cent of the patients showed no identifiable antecedent trauma. Seventy-one per cent of tissue culture-positive patients (145) had multibacterial infections. Although no streptococcal species were recovered from one-third of these culture-positive patients there was an increase in mortality noted with β- Streptococcus infections. Ninety-six per cent of the patient deaths were correlated with variables organized into the following categories: 1) patient history (intravenous drug use and age <1 or >60 years), 2) comorbid conditions (cancer, renal disease, and congestive heart failure), 3) characteristics of clinical course (trunk involvement, positive blood cultures, peripheral vascular disease, and positive cultures for β -streptococcus or anaerobic bacteria), and 4) quantitative timeline of clinical course (time: injury to diagnosis, diagnosis to treatment). Mortality is correlated to patient history, comorbid conditions, and progression of clinical course. Necrotizing fasciitis can occur idiopathically and is generally a polymicrobial infection that sometimes occurs in the absence of streptococci. Clearly the mortality and morbidity associated with necrotizing fasciitis can be decreased with clinical awareness, early diagnosis, adequate surgical debridement, and intensive supportive care.

Massive infectious soft-tissue injury: diagnosis and management of necrotizing fasciitis and purpura fulminans

LEARNING OBJECTIVES

After studying the article, the participant should be able to: 1. Describe the most common bacteriology of necrotizing fasciitis and purpura fulminans. 2. Describe the "finger test" in the diagnosis of necrotizing fasciitis. 3. Discuss the three presentation patterns of necrotizing fasciitis. 4. Discuss the pathophysiology of acute infectious purpura fulminans. 5. Discuss the treatment strategies for necrotizing fasciitis and purpura fulminans, including the use of artificial skin substitutes. Necrotizing fasciitis and purpura fulminans are two destructive processes that involve skin and soft tissues. The plastic and reconstructive surgeon may frequently be called on for assistance in the diagnosis, treatment, and/or reconstruction of patients with these conditions. Understanding the natural history and unique characteristics of these processes is essential for effective surgical management and favorable patient outcome. A comprehensive review of the literature pertaining to these two conditions is presented, outlining the different pathophysiologies, the patterns of presentation, and the treatment strategies necessary for successful management of these massive infectious soft-tissue diseases.

Cervical necrotizing fasciitis of odontogenic origin: a case report and review of 12 cases

PURPOSE

This article reviews the demographics, presentation, cause, clinical findings, and treatment of 12 cases of cervical necrotizing fasciitis of odontogenic origin.

PATIENTS AND METHODS

A retrospective chart review of 12 cases treated between 1987 and 1997 was done.

RESULTS

Most cases resulted from an abscessed mandibular molar. The most common significant medical conditions in the patient's history were diabetes, hypertension, obesity, and substance abuse. All patients were treated surgically within 24 hours of admission. Hyperbaric oxygen (HBO) was used as adjunctive treatment in all cases. The average length of hospital stay was 31 days. All patients recovered.

CONCLUSION

Early surgical intervention and the use of HBO decreases morbidity and improves the clinical outcome.

Can we learn from the pathogenetic strategies of group A hemolytic streptococci how tissues are injured and organs fail in post-infectious and inflammatory sequelae?

The purpose of this review-hypothesis is to discuss the literature which had proposed the concept that the mechanisms by which infectious and inflammatory processes induce cell and tissue injury, in vivo, might paradoxically involve a deleterious synergistic 'cross-talk', among microbial- and host-derived pro-inflammatory agonists. This argument is based on studies of the mechanisms of tissue damage caused by catalase-negative group A hemolytic streptococci and also on a large body of evidence describing synergistic interactions among a multiplicity of agonists leading to cell and tissue damage in inflammatory and infectious processes. A very rapid cell damage (necrosis), accompanied by the release of large amounts of arachidonic acid and metabolites, could be induced when subtoxic amounts of oxidants (superoxide, oxidants generated by xanthine-xanthine oxidase, HOCl, NO), synergized with subtoxic amounts of a large series of membrane-perforating agents (streptococcal and other bacterial-derived hemolysins, phospholipases A2 and C, lysophosphatides, cationic proteins, fatty acids, xenobiotics, the attack complex of complement and certain cytokines). Subtoxic amounts of proteinases (elastase, cathepsin G, plasmin, trypsin) very dramatically further enhanced cell damage induced by combinations between oxidants and the membrane perforators. Thus, irrespective of the source of agonists, whether derived from microorganisms or from the hosts, a triad comprised of an oxidant, a membrane perforator, and a proteinase constitutes a potent cytolytic cocktail the activity of which may be further enhanced by certain cytokines. The role played by non-biodegradable microbial cell wall components (lipopolysaccharide, lipoteichoic acid, peptidoglycan) released following polycation- and antibiotic-induced bacteriolysis in the activation of macrophages to release oxidants, cytolytic cytokines and NO is also discussed in relation to the pathophysiology of granulomatous inflammation and sepsis. The recent failures to prevent septic shock by the administration of only single antagonists is disconcerting. It suggests, however, that since tissue damage in post-infectious syndromes is caused by synergistic interactions among a multiplicity of agents, only cocktails of appropriate antagonists, if administered at the early phase of infection and to patients at high risk, might prevent the development of post-infectious syndromes.