Saksenaea vasiformisinfection in a burn wound

Mucormycosis following burn injuries: A systematic review

INTRODUCTION

Mucormycosis is an opportunistic fungal infection with a high mortality rate. Though typically associated with diabetes and other conditions that affect innate immune function, infections can also be precipitated by conditions such as trauma and burns. Burn patients are particularly susceptible to fungal infections due to the immune dysfunction that often accompany their wounds. Indeed case series have described mucormycosis to occur in patients with burn injuries, however the factors contributing to mortality have not been well described. Thus, the purpose of our review was to identify factors contributing to morbidity and mortality in burn patients with Mucormycosis.

METHODS

A systematic review of the literature of mucormycosis infection in burn injury patients was performed on Pubmed and Google Scholar using the keywords: Mucor, Mucorales, Mucormycosis, Mucormycotina, Zygomycosis and burn or thermal injury. Clinical trials, observational studies, case reports, and case reviews were included if they provided information regarding mortality in adult and pediatric burn patients diagnosed with mucormycosis, review articles, non-English articles, and articles without patient information were excluded. No time limit was placed on our review. Individual patient data was stratified based on mortality. Statistical analysis was performed to investigate the relationship between patient risk factors and mortality, and the Oxford Level of Evidence was used to evaluate study quality.

RESULTS

46 articles were included in our final review, encompassing 114 patients. On average, survivors had a total body surface area (TBSA)% of 46 (SD 19.8) while non-survivors had a TBSA of 65% (SD 16.4), and this difference was significant (p < .001). Patients with disseminated mucormycosis experienced an 80% mortality rate compared to 36% mortality rate in patients with localized disease (p < .001). We found no statistically significant difference in mean age (p > .05), diabetes (p > .05), mean delay in diagnosis (p > .05), time to antifungal therapy (p > .05), or type of therapy used (p > .05) between survivors and non-survivors. Our review was limited by the lack of prospective, controlled trials; thus, our review primarily consists of case reports.

CONCLUSION

Disseminated infections and higher TBSA both increased the risk of mortality in burn patients with mucormycosis, while diabetes did not increase mortality risk. The severity of the initial injury and infection locations must be taken into consideration to inform patient prognosis.

Mucormycosis in burns: a review

Mucormycosis is a rare fungal infection with a high mortality rate. It presents with scattered black/necrotic ulcers, white fungal elements, and progression of wounds despite seemingly adequate debridement. Diagnosis is confirmed on wound histology, however this is often delayed. There is currently no comprehensive review of burn related mucormycosis within the literature, making this the first paper to provide evidence-based treatment guidance. We performed a review of publications from 1946 - present. There were 151 cases of mucormycosis complicating burns. The mortality rate was 54.5%, and there was a significant increase in mortality with axial body site involvement compared with isolated peripheral involvement. The standard treatment was prompt and radical debridement. Utilisation of frozen section to guide debridement aided in clinical decision making. No systemic treatment reached statistical significance, however amphotericin B trended towards significance. Although there is no strong evidence for topical amphotericin B or hyperbaric oxygen, there may be benefit in some cases. This study recommends early radical debridement in conjunction with the European Confederation of Medical Mycology guidelines of IV liposomal/lipid complex amphotericin B >5mg/kg/day, with posaconazole 800mg daily in divided doses as a salvage or oral step-down 1.

Saksenaea vasiformis infections: A case of an immunocompetent adult after mild injury and a literature review

Saksenaea vasiformis is an emerging human pathogen, belonging to the order Mucorales of the subphylum Mucormycotina, most often associated with rhino-cerebral, cutaneous and subcutaneous infections following trauma. A review of the published literature was attempted on the occasion of a cutaneous leg infection with favorable outcome in a young immunocompetent man after mild injury. The overall aim was the facilitation of the study and the integrated understanding of this kind of fungal infections.

[Necrotising fasciitis caused by Saksenaea vasiformis in an immunocompetent patient after a car accident]

BACKGROUND

Cutaneous mucormycosis (zygomycosis), with subcutaneous spreading and dissemination, in immunocompetent patients is an uncommon disease caused by species belonging to the fungal genera Apophysomyces, Rhizopus and Saksenaea, among others.

CASE REPORT

A case of necrotising fasciitis by Saksenaea vasiformis in an immunocompetent woman is described. The infection was acquired through a car accident resulting in multiple injuries affecting mainly her right arm. After the surgical reduction of fractures, skin lesions worsened and led to necrosis. The patient quickly developed a severe necrotising fasciitis with negative cultures at first. Despite the extensive surgical debridement and the aggressive antifungal treatment, the patient died. The histopathological study showed a fungal infection due to a fungus belonging to the Mucorales order, which was confirmed by culturing the clinical sample on Sabouraud agar, and identifying the species by cultures on Czapek-Dox agar, and sequencing of the ITS region of the ribosomal DNA.

CONCLUSIONS

This case confirm the presence of this fungus in Spain, the value of histopathology for the mucormycosis diagnosis, as well as the need to perform special cultures to facilitate their isolation and identification to the species level by the combined use of Czapek-Dox agar and sequencing of the ITS region.

Saksenaea erythrospora infection following combat trauma

Saksenaea erythrospora is a newly described species of the order Mucorales which has not previously been reported as a cause of human infection. We report a fatal case of S. erythrospora invasive burn wound infection in a 26-year-old male injured during combat operations in Iraq.

Mucormycosis caused by unusual mucormycetes, non-Rhizopus, -Mucor, and -Lichtheimia species

Rhizopus, Mucor, and Lichtheimia (formerly Absidia) species are the most common members of the order Mucorales that cause mucormycosis, accounting for 70 to 80% of all cases. In contrast, Cunninghamella, Apophysomyces, Saksenaea, Rhizomucor, Cokeromyces, Actinomucor, and Syncephalastrum species individually are responsible for fewer than 1 to 5% of reported cases of mucormycosis. In this review, we provide an overview of the epidemiology, clinical manifestations, diagnosis of, treatment of, and prognosis for unusual Mucormycetes infections (non-Rhizopus, -Mucor, and -Lichtheimia species). The infections caused by these less frequent members of the order Mucorales frequently differ in their epidemiology, geographic distribution, and disease manifestations. Cunninghamella bertholletiae and Rhizomucor pusillus affect primarily immunocompromised hosts, mostly resulting from spore inhalation, causing pulmonary and disseminated infections with high mortality rates. R. pusillus infections are nosocomial or health care related in a large proportion of cases. While Apophysomyces elegans and Saksenaea vasiformis are occasionally responsible for infections in immunocompromised individuals, most cases are encountered in immunocompetent individuals as a result of trauma, leading to soft tissue infections with relatively low mortality rates. Increased knowledge of the epidemiology and clinical presentations of these unusual Mucormycetes infections may improve early diagnosis and treatment.

Saksenaea vasiformis infections: case report and literature review

Since the first human infection by Saksenaea vasiformis in 1976 another 26 cases have been reported. Here is a report of a new case which involved an Ecuadorian adolescent who suffered serious burns after a car accident. It developed as a localized cutaneous infection which was successfully treated with surgical debridement and amphotericin B. This is the second report of this infection from South America and the third involving a burn patient. The previously reported 27 cases are reviewed.

Zygomycetes in human disease

The Zygomycetes represent relatively uncommon isolates in the clinical laboratory, reflecting either environmental contaminants or, less commonly, a clinical disease called zygomycosis. There are two orders of Zygomycetes containing organisms that cause human disease, the Mucorales and the Entomophthorales. The majority of human illness is caused by the Mucorales. While disease is most commonly linked to Rhizopus spp., other organisms are also associated with human infection, including Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces, and Syncephalastrum spp. Although Mortierella spp. do cause disease in animals, there is no longer sufficient evidence to suggest that they are true human pathogens. The spores from these molds are transmitted by inhalation, via a variety of percutaneous routes, or by ingestion of spores. Human zygomycosis caused by the Mucorales generally occurs in immunocompromised hosts as opportunistic infections. Host risk factors include diabetes mellitus, neutropenia, sustained immunosuppressive therapy, chronic prednisone use, iron chelation therapy, broad-spectrum antibiotic use, severe malnutrition, and primary breakdown in the integrity of the cutaneous barrier such as trauma, surgical wounds, needle sticks, or burns. Zygomycosis occurs only rarely in immunocompetent hosts. The disease manifestations reflect the mode of transmission, with rhinocerebral and pulmonary diseases being the most common manifestations. Cutaneous, gastrointestinal, and allergic diseases are also seen. The Mucorales are associated with angioinvasive disease, often leading to thrombosis, infarction of involved tissues, and tissue destruction mediated by a number of fungal proteases, lipases, and mycotoxins. If the diagnosis is not made early, dissemination often occurs. Therapy, if it is to be effective, must be started early and requires combinations of antifungal drugs, surgical intervention, and reversal of the underlying risk factors. The Entomophthorales are closely related to the Mucorales on the basis of sexual growth by production of zygospores and by the production of coenocytic hyphae. Despite these similarities, the Entomophthorales and Mucorales have dramatically different gross morphologies, asexual reproductive characteristics, and disease manifestations. In comparison to the floccose aerial mycelium of the Mucorales, the Entomophthorales produce a compact, glabrous mycelium. The asexually produced spores of the Entomophthorales may be passively released or actively expelled into the environment. Human disease with these organisms occurs predominantly in tropical regions, with transmission occurring by implantation of spores via minor trauma such as insect bites or by inhalation of spores into the sinuses. Conidiobolus typically infects mucocutaneous sites to produce sinusitis disease, while Basidiobolus infections occur as subcutaneous mycosis of the trunk and extremities. The Entomophthorales are true pathogens, infecting primarily immunocompetent hosts. They generally do not invade blood vessels and rarely disseminate. Occasional cases of disseminated and angioinvasive disease have recently been described, primarily in immunocompromised patients, suggesting a possible emerging role for this organism as an opportunist.

Subcutaneous zygomycosis due to Saksenaea vasiformis: rapid isolate identification using a modified sporulation technique

Saksenaea vasiformis, a zygomycete belonging to the order Mucorales, is a rare cause of zygomycosis with 17 cases documented world-wide. It usually infects the immunocompromised or traumatized and has a high mortality rate. Because of its failure to sporulate under normal laboratory conditions it may be difficult to identify. We describe here an unusual case report of Saksenaea vasiformis with sporulation and identification within a week using a modified sporulation technique.

Soft-tissue fungal infections: surgical management of 12 immunocompromised patients

Isolated fungal soft-tissue infections are uncommon but may cause severe morbidity or mortality among transplant recipients and other immunosuppressed patients. Twelve immunocompromised patients illustrating three patterns of infection were treated recently at the Duke University Medical Center. These groups comprised (I) locally aggressive infections, (II) indolent infections, and (III) cutaneous manifestations of systemic infection. Patient diagnoses included organ transplant, leukemia, prematurity, chronic obstructive pulmonary disease, and rheumatoid arthritis. Time from immunosuppression to biopsy ranged from 5.5 to 31 weeks. Organisms included Aspergillus, Rhizopus, Fusarium, Paecilomyces, Exophiala, and Curvularia. Patients presented with necrotic ulcerations or nodules. Surgical treatment ranged from radical debridement to excisional biopsy to none. Antifungal chemotherapy also was employed in some cases. The mortality rate was 33 percent, two patients dying without evidence of fungal infection. Six of the eight survivors cleared their infections. Necrotic skin lesions with surrounding erythema in this population call for prompt examination, biopsy, and culture. Group I lesions mandate radical excision with rapid intraoperative microscopic control and systemic antifungal medication. Group II requires surgical control with or without antifungal therapy. Group III requires systemic antifungal therapy for metastatic infection. In our opinion, treatment of fungal soft-tissue infection should be tailored to infection type and requires a team approach of surgeon and expert infectious disease consultation.

Cutaneous zygomycosis caused by Saksenaea vasiformis in a diabetic patient

A 49-year-old woman with diabetes mellitus rapidly developed necrotizing cellulitis with fat necrosis and vasculitis after minor trauma to the right arm. Zygomycosis was diagnosed histologically. The lesion responded to aggressive debridement, amphotericin B, and normalization of blood glucose. Cultures yielded structures characteristic of Saksenaea vasiformis only after transfer to saline agar.