Absidia corymbifera Fungal Infection in Burns: A Case Report and Review of the Literature:

Invasive Non-Candida Fungal Infections in Acute Burns-A 13-Year Review of a Single Institution and Review of the Literature

The past decade has demonstrated increased burn wound infections with atypical invasive fungal organisms. The range of previously regiospecific organisms has expanded, and plant pathogens are increasingly represented. Our institution sought to examine changes in severe fungal non-Candida infections in our patients, via retrospective review of patients admitted to our burn center from 2008 to 2021. We identified 37 patients with atypical invasive fungal infections. Non-Candida genera included Aspergillus (23), Fusarium (8), Mucor (6), and 13 cases of 11 different species, including the second-ever human case of Petriella setifera. Three fungi were resistant to at least one antifungal. Concomitant infections included Candida (19), Staphylococcus and Streptococcus (14), Enterococcus and Enterobacter (13), Pseudomonas (9), and 14 additional genera. Complete data was available for 18 patients, who had a median of 3.0 (IQR 8.5, range 0-15) additional bacteria required a median of 1 (IQR 7, range 0-14) systemic antibacterials and 2 (IQR 2.5, range 0-4) systemic antifungals. One case of total-drug-resistant Pseudomonas aeruginosa required bacteriophage treatment. One case of Treponema pallidum was found in infected burn wound tissue. Every patient required Infectious Disease consultation. Eight patients became bacteremic and one developed Candida fermentatifungemia. There were five patient deaths (13.8%), all due to overwhelming polymicrobial infection. Burn patients with atypical invasive fungal infections can have severe concomitant polymicrobial infections and multidrug resistance with fatal results. Early Infectious Disease consultation and aggressive treatment is critical. Further characterization of these patients may provide better understanding of risk factors and ideal treatmentpatterns.

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.

Risk Assessment for Molds in the Vicinity of a Child Requiring Peritoneal Dialysis Living in a Rural Northern German Area

As well as severe immunosuppression, other predisposing factors may facilitate invasive mycosis caused by molds. Chronic kidney disease and the resulting peritoneal dialysis have been reported as factors putting patients at risk of fungal infections from environmental sources. We describe an environmental investigation undertaken to guide exposure prevention for a peritoneal dialysis patient with transient colonization of her nostrils by Lichtheimia corymbifera in a rural area of northern Germany. Systematic screening for airborne and surface-deposited molds enabled targeted recommendations to be made, although Lichtheimia corymbifera itself was not grown from the collected environmental samples. This communication is intended to illustrate how such an investigation can be performed on the basis of the environmental distribution of the molds and how preventive recommendations can be derived from the results.

Factors Associated with Mortality Following Burns Complicated by Necrotizing Skin and Soft Tissue Infections: A Systematic Review and Meta-analysis of Individual Participant Data

We reviewed studies with individual participant data of patients who sustained burn injury and subsequently developed necrotizing skin and soft tissue infections (NSTI). Characteristics and managements were compared between patients who lived and patients who died to determine factors associated with mortality. Six databases (PubMed, EMBASE, Cochrane Library, Web of Science, Scopus and CINAHL) were searched. PRISMA-IPD guidelines were followed throughout the review. Eligible patients sustained a burn injury, treated in any setting, and diagnosed with a NSTI following burn injury. Comparisons were made between burned patients who lived "non-mortality" and burned patients who died "mortality" following NSTI using non-parametric univariate analyses. Fifty-eight studies with 78 patients were published from 1970 through 2019. Non-mortality resulted in 58 patients and mortality resulted in 20 patients. Patients with mortality had significantly greater median %TBSA burned (45%[IQR:44-64%] versus 35%[IQR:11-59%],p=0.033), more intubations (79% versus 43%,p=0.013), less debridements (83% versus 98%,p=0.039), less skin excisions (83% versus 98%,p=0.039), more complications (100% versus 50%,p<0.001), management at a burn center (100% versus 71%,p=0.008), underwent less flap surgeries (5% versus 35%,p=0.014), less graft survival (25% versus 86%,p<0.001), and less healed wounds (5% versus 95%,p<0.001), compared to patients with non-mortality, respectively. Non-mortality patients had more debridements, skin excised, systemic antimicrobials, skin graft survival, flaps, improvement following surgery and healed wounds compared to mortality patients. Mortality patients had greater %TBSA burned, intubations, management at a burn center and complications compared to non-mortality patients.

Mucormycosis treatment: Recommendations, latest advances, and perspectives

Mucormycosis are life-threatening fungal infections especially affecting immunocompromised or diabetic patients. Despite treatment, mortality remains high (from 32 to 70% according to organ involvement). This review provides an update on mucormycosis management. The latest recommendations strongly recommend as first-line therapy the use of liposomal amphotericin B (≥5mg/kg) combined with surgery whenever possible. Isavuconazole and intravenous or delayed-release tablet forms of posaconazole have remained second-line. Many molecules are currently in development to fight against invasive fungal diseases but few have demonstrated efficacy against Mucorales. Despite in vitro efficacy, combinations of treatment have failed to demonstrate superiority versus monotherapy. Adjuvant therapies are particularly complex to evaluate without prospective randomized controlled studies, which are complex to perform due to low incidence rate and high mortality of mucormycosis. Perspectives are nonetheless encouraging. New approaches assessing relationships between host, fungi, and antifungal drugs, and new routes of administration such as aerosols could improve mucormycosis treatment.

Mucormycosis in Burn Patients

Patients with extensive burns are an important group at risk for cutaneous mucormycosis. This study aimed to perform a systematic review of all reported mucormycosis cases in burn patients from 1990 onward. A Medline search yielded identification of 7 case series, 3 outbreaks, and 25 individual cases reports. The prevalence reached 0.04%–0.6%. The median age was 42–48 in the case series and outbreaks, except for the studies from military centers (23.5–32.5) and in individual reports (29.5). The median total body surface area reached 42.5%–65%. Various skin lesions were described, none being pathognomonic: the diagnosis was mainly reached because of extensive necrotic lesions sometimes associated with sepsis. Most patients were treated with systemic amphotericin B or liposomal amphotericin B, and all underwent debridement and/or amputation. Mortality reached 33%–100% in the case series, 29%–62% during outbreaks, and 40% in individual cases. Most patients were diagnosed using histopathology and/or culture. Mucorales qPCR showed detection of circulating DNA 2–24 days before the standard diagnosis. Species included the main clinically relevant mucorales (i.e., Mucor, Rhizopus, Absidia/Lichtheimia, Rhizomucor) but also more uncommon mucorales such as Saksenaea or Apophysomyces. Contact with soil was reported in most individual cases. Bandages were identified as the source of contamination in two nosocomial outbreaks.

Candida parapsilosis isolates from burn wounds can penetrate an acellular dermal matrix

We isolated and identified yeasts from burn wounds and evaluated the ability of Candida parapsilosis isolates from burn wounds to penetrate an acellular dermal matrix (ADM). A prospective study was conducted with patients from the burn treatment center of North Paraná University Hospital in Londrina, Brazil from February 2015 to January 2016. Yeast cultures were obtained from the tissue of burn wounds that had been debrided and cleansed with 2% chlorhexidine. After identification and confirmation of the purity of the culture, the yeasts were placed on ADM fragments and incubated for three or seven days. During the study period, 273 patients were treated, and 36 of these patients fulfilled the inclusion criteria and provided samples for culture. Yeasts were isolated in 19.44% (n = 7) of the cultures, and the following species were identified: C. parapsilosis (57.1%), C. albicans (28.6%), and C. glabrata (14.3%). C. parapsilosis, the most frequent species, was chosen for the ADM tests. We demonstrated active penetration of the ADM by the yeast isolates from burn wounds. C. parapsilosis grew on ADM and penetrated the matrix, indicating that this yeast, which is common in skin and cutaneous wounds, has the potential to colonize and pass through ADM, a medical device that is frequently used to dress and regenerate burn wounds.

Yeasts from skin colonization are able to cross the acellular dermal matrix

In recent decades, the prognosis for burn patients has improved considerably with the development of specialized care. The acellular dermal matrix (ADM) is a totally artificial acellular device that functions to control water loss, prevent penetration by bacteria and allow migration of endothelial cells and fibroblasts from patient tissues. However, little is known about its effectiveness against yeasts. The present study evaluated the capacity of colonization and migration of some human commensal yeasts. Three clinical isolates from skin scales, identified as Candida parapsilosis, Candida glabrata and Rhodotorula mucilaginosa, were used. Their ability to cross the ADM was evaluated. After three days, all isolates had crossed the ADM. C. parapsilosis showed the lowest growth, while R. mucilaginosa showed intermediate and C. glabrata the highest growth. In the plates incubated for seven days, the growth of C. parapsilosis and C. glabrata increased by 1 log over the third day. All isolates have the capacity to colonize and migrate through the matrix, increasing the potential risk to burn patients, who can develop severe and even fatal infections by invasive fungi.

Primary Gangrenous Cutaneous Mold Infections in a Patient With Cancer and Neutropenia

BACKGROUND

Opportunistic fungal infections caused by Aspergillus and Candida followed by infections with Fusarium, Rhizopus, Mucor, and Alternaria species are an important cause of morbidity and mortality in patients with hematological malignancies. Cutaneous mucormycosis infections are rare, and the incidence, outcomes, and factors associated with survival in the setting of hematological malignancies are not clear.

METHODS

A literature search was conducted for all cases of primary cutaneous mold infections in patients with hematological malignancy, of which 50 cases were found. Our case of a patient with a hematological malignancy who sustained a cat bite that in turn caused a primary cutaneous mold infection is also included.

RESULTS

In the 51 cases identified, 66.7% were neutropenic upon presentation, and 54.9% were male with an average age of 32 years. Aspergillus species (33.3%) was the most cited followed by Rhizopus species (19.6%). Overall mortality rate was 29.4% and was observed more frequently in patients with neutropenia (60.0%) and without surgical intervention (73.3%). Survival rate was higher (35.3%) for cases utilizing both antifungal and surgical intervention. The antifungal agent with the highest survival rate was amphotericin B and its formulations (58.8%).

CONCLUSIONS

Neutropenia within hematological malignancies demonstrate a risk for developing severe cutaneous fungal infections, of which primary cutaneous mucormycosis can carry significant mortality. Combination antifungal therapy and surgical debridement appears to be associated with higher survival outcomes and warrants further investigation.

Sapronosis: a distinctive type of infectious agent

Sapronotic disease agents have evolutionary and epidemiological properties unlike other infectious organisms. Their essential saprophagic existence prevents coevolution, and no host-parasite virulence trade-off can evolve. However, the host may evolve defenses. Models of pathogens show that sapronoses, lacking a threshold of transmission, cannot regulate host populations, although they can reduce host abundance and even extirpate their hosts. Immunocompromised hosts are relatively susceptible to sapronoses. Some particularly important sapronoses, such as cholera and anthrax, can sustain an epidemic in a host population. However, these microbes ultimately persist as saprophages. One-third of human infectious disease agents are sapronotic, including nearly all fungal diseases. Recognition that an infectious disease is sapronotic illuminates a need for effective environmental control strategies.

Fungal infections in burns: Diagnosis and management

Burn wound infection (BWI) is a major public health problem and the most devastating form of trauma worldwide. Fungi cause BWI as part of monomicrobial or polymicrobial infection, fungaemia, rare aggressive soft tissue infection and as opportunistic infections. The risk factors for acquiring fungal infection in burns include age of burns, total burn size, body surface area (BSA) (30-60%), full thickness burns, inhalational injury, prolonged hospital stay, late surgical excision, open dressing, artificial dermis, central venous catheters, antibiotics, steroid treatment, long-term artificial ventilation, fungal wound colonisation (FWC), hyperglycaemic episodes and other immunosuppressive disorders. Most of the fungal infections are missed owing to lack of clinical awareness and similar presentation as bacterial infection coupled with paucity of mycology laboratories. Expedient diagnosis and treatment of these mycoses can be life-saving as the mortality is otherwise very high. Emergence of resistance in non-albicans Candida spp., unusual yeasts and moulds in fungal BWI, leaves very few fungi susceptible to antifungal drugs, leaving many patients susceptible. There is a need to speciate fungi as far as the topical and systemic antifungal is concerned. Deep tissue biopsy and other relevant samples are processed by standard mycological procedures using direct microscopy, culture and histopathological examination. Patients with FWC should be treated by aggressive surgical debridement and, in the case of fungal wound infection (FWI), in addition to surgical debridement, an intravenous antifungal drug, most commonly amphotericin B or caspofungin, is prescribed followed by de-escalating with voriconazole or itraconazole, or fluconazole depending upon the species or antifungal susceptibility, if available. The propensity for fungal infection increases, the longer the wound is present. Therefore, the development of products to close the wound more rapidly, improvement in topical antifungal therapy with mould activity and implementation of appropriate systemic antifungal therapy guided by antifungal susceptibility may improve the outcome for severely injured burn victims.

Epidemiological and clinico-mycological profile of fungal wound infection from largest burn centre in Asia

The current study was conducted to know the incidence, predisposing factors, spectrum, clinical profile and antifungal susceptibility (AFS) of fungal wound infection (FWI) in burn patients. Of a total of 71 patients, 20 (28.2%) emerged with the diagnosis of FWI. Fungal pathogens in this study were Candida tropicalis (14%), Candida parapsilosis (5.6%), Aspergillus niger (2.8%) and one each of Candida albicans (1.4%), Candida glabrata (1.4%), Syncephalestrum (1.4%) and Fusarium solani (1.4%). All patients with mould infections expired before the mycological culture results could be conveyed to clinicians. Of the yeasts isolated in the study, one each of C. tropicalis and C. albicans showed cross-resistance to azoles. All the moulds were susceptible to amphotericin B. This study depicted that fungal invasion is associated with a high mortality, burn size 30-60% and high incidence of inhalational injury. Fungal invasion was detected on an average of 14 days after injury. Association of use of four classes of drugs - aminoglycosides, imipenem, vancomycin and third generation cephalosporins and use of total parenteral nutrition was observed. Expedient laboratory diagnosis of FWI and appropriate systemic antifungal therapy guided by AFS may improve outcome for severely injured burn victims.

Lichtheimia hongkongensis sp. nov., a novel Lichtheimia spp. associated with rhinocerebral, gastrointestinal, and cutaneous mucormycosis

Three thermotolerant "Absidia-like" isolates with unique morphologic characteristics, recovered from nasopharyngeal swab of a liver transplant recipient, gastric biopsy of a renal transplant recipient, and skin biopsy of a man with burn, respectively, were characterized. Microscopic examination showed nonseptate hyphae with highly branched sporangiophores. Uniquely, most side branches were circinate, and abundant pleomorphic giant cells with fingerlike projections were observed, characteristics absent from other Absidia/Lichtheimia spp. ITS1-5.8S-ITS2 rRNA gene cluster, partial EF1alpha gene, and partial beta-actin gene sequencing showed that the 3 strains formed a distinct cluster, most closely related to, but distinct from, Lichtheimia corymbifera, Lichtheimia blakesleeana, and Lichtheimia hyalospora. Based on the morphologic and genotypic characteristics, we propose a new species, Lichtheimia hongkongensis sp. nov., to describe this fungus, which caused rhinocerebral, gastrointestinal, and cutaneous mucormycosis, respectively, in 3 patients. A significant proportion of L. corymbifera associated with mucormycosis reported may be L. hongkongensis.

Fatal Actinomucor elegans var. kuwaitiensis infection following combat trauma

We report the first case of invasive mucormycosis secondary to Actinomucor elegans infection. A severely injured soldier with a fatal A. elegans var. kuwaitiensis infection is described. The identification of this fungus was performed by classical and molecular methods, and this report documents the pathogenicity of the recently described variety Actinomucor elegans var. kuwaitiensis.