Epidemiology and clinical manifestations of mucormycosis

Liquid biopsy for infectious diseases: sequencing of cell-free plasma to detect pathogen DNA in patients with invasive fungal disease

Diagnosis of life-threatening deep-seated infections currently requires invasive sampling of the infected tissue to provide a microbiologic diagnosis. These procedures can lead to high morbidity in patients and add to healthcare costs. Here we describe a novel next-generation sequencing assay that was used to detect pathogen-derived cell-free DNA in peripheral blood of patients with biopsy-proven invasive fungal infections. The noninvasive nature of this approach could provide rapid, actionable treatment information for invasive fungal infections when a biopsy is not possible.

A New Method for Reactivating and Expanding T Cells Specific for Rhizopus oryzae

Mucormycosis is responsible for an increasing proportion of deaths after allogeneic bone marrow transplantation. Because this disease is associated with severe immunodeficiency and has shown resistance to even the newest antifungal agents, we determined the feasibility of reactivating and expanding Rhizopus oryzae-specific T cells for use as adoptive immunotherapy in transplant recipients. R. oryzae extract-pulsed monocytes were used to stimulate peripheral blood mononuclear cells from healthy donors, in the presence of different cytokine combinations. The generated R. oryzae-specific T cell products were phenotyped after the third stimulation and further characterized by the use of antibodies that block class I/II molecules, as well as pattern recognition receptors. Despite the very low frequency of R. oryzae-specific T cells of healthy donors, we found that stimulation with interleukin-2 (IL-2)/IL-7 cytokine combination could expand these rare cells. The expanded populations included 17%-83% CD4+ T cells that were specific for R. oryzae antigens. Besides interferon-γ (IFN-γ), these cells secreted IL-5, IL-10, IL-13, and tumor necrosis factor alpha (TNF-α), and recognized fungal antigens presented by HLA-II molecules rather than through nonspecific signaling. The method described herein is robust and reproducible, and could be used to generate adequate quantities of activated R. oryzae-specific T cells for clinical testing of safety and antifungal efficacy in patients with mucormycosis.

Recent Advances in the Pathogenesis of Mucormycoses

PURPOSE

The purposes of this review are to describe the pathogenesis of mucormycosis and to address recent research advances in understanding the mechanisms of fungal invasion and dissemination.

METHODS

Studies and reviews published in the PubMed and ClinicalTrials.gov databases until December 2017 that explored or reported recent advances in the understanding of the pathogenesis of mucormycosis were reviewed.

FINDINGS

To cause disease, fungal spores need to evade the innate immune system and germinate, leading to angioinvasion and tissue destruction. Recent studies have found that Mucorales are able to downregulate several host defense mechanisms and have identified the specific receptors through which Mucorales attach to the endothelium, facilitating their endocytosis and subsequent angioinvasion. In addition, certain conditions found to act through various mechanisms and pathways in experimental and animal studies, such as hyperglycemia, elevated iron concentrations, and acidosis (particularly diabetic ketoacidosis), increase the virulence of the fungi and enhance their attachment to the endothelium, rendering patients with uncontrolled diabetes and patients with iron overload susceptible to mucormycosis. The role and various antifungal functions of platelets and natural killer cells are highlighted, and the potential contribution of alternative therapies, such as manipulating the innate immune host defenses with granulocyte transfusions or administration of growth factors and using the antifungal effects of calcineurin inhibitors, are presented. Finally, directions and possible implications for future research are provided.

IMPLICATIONS

This article provides a comprehensive overview of research advances in the pathogenesis of infections caused by Mucorales and helps future studies develop effective treatment strategies and improve patient outcomes.

Inflammatory and infectious manifestations of immunodeficiency in the gastrointestinal tract

Immune compromise may result from genetic abnormalities, HIV/AIDS, or consequences of therapy for neoplastic and autoimmune diseases. Many immunocompromised patients develop severe gastrointestinal symptoms, particularly diarrhea, accompanied by non-specific or mild endoscopic abnormalities; mucosal biopsy with pathologic interpretation has a major role in the diagnosis and management of these patients. Immunocompromised individuals are at risk for all the diseases that affect those with a healthy immune system, but they are also prone to other illnesses that rarely affect immunocompetent patients. This review discusses the gastrointestinal manifestations of primary and acquired immunodeficiency, chemotherapy-related injury, and infections that show a predilection for immunocompromised patients. Key histologic features and relevant differential diagnoses are emphasized.

Isolated cutaneous mucormycosis in a pediatric renal transplant recipient

Mucormycosis is a rare and potentially life-threatening infection, typically affecting immunocompromised hosts. We report a case of an adolescent boy who developed primary isolated cutaneous mucormycosis in the early period following kidney transplantation. Surgical excision was performed using intraoperative fungal staining to obtain clear margins, followed by topical and systemic antifungal therapy. A skin graft was then applied to the excised area with good healing, and the patient made a full recovery.

Voriconazole associated mucormycosis in a patient with relapsed acute lymphoblastic leukemia and hematopoietic stem cell transplant failure: A case report

The patients with hematologic malignancies and hematopoietic stem cell transplantation (HSCT) recipients are at high risk for invasive fungal diseases (IFDs) mainly due to the severe and prolonged neutropenia related to high-dose chemotherapy. Voriconazole prophylaxis is recommended for possible IFDs. Mucormycosis is a fulminant infection, which may occur after voriconazole prophylaxis for invasive aspergillosis in immunocompromised hosts. Here, we report mucormycosis after 4 months of voriconazole prophylaxis in a young patient with relapsed acute lymphoblastic leukemia and hematopoietic stem cell transplant failure and discuss the clinical manifestation, imaging, laboratory findings and therapeutic regimens. Clinician's awareness of this entity and timely diagnosis using conventional and molecular methods are the promising approach for the management of this devastating infection.

Identification of a Novel Rhizopus-specific Antigen by Screening with a Signal Sequence Trap and Evaluation as a Possible Diagnostic Marker of Mucormycosis

Mucormycosis is the second most common mould infection, often indistinguishable from other invasive mould infections such as aspergillosis. Although an appropriate antifungal therapy is effective at an early stage of the infection, there is no reliable diagnostic method for decision making. Thus, it is necessary to develop an efficient method that can detect mucormycosis rapidly and accurately. We searched for secreted or membrane-bound proteins of Rhizopus oryzae, which is the most common pathogen of mucormycosis, using the method of a signal sequence trap by retrovirus-mediated expression (SST-REX). Among the identified proteins, a Rhizopus-specific antigen was selected as a candidate, and efficacy of this specific antigen was evaluated using R. oryzae-infected mice. Of 302 clones obtained from the SST-REX library, a hypothetical protein (23 kDa, named "protein RSA") was selected as a candidate because of its highest prevalence of clones. Protein RSA was detected at significantly higher concentrations in serum and in lung homogenates of the infected mice as compared to those of uninfected mice. Our study indicates that protein RSA may be a promising biomarker of R. oryzae infection. SST-REX may be useful for comprehensive screening of prospective eukaryotic biomarkers of intractable mould infections.

Components of a new gene family of ferroxidases involved in virulence are functionally specialized in fungal dimorphism

Mucormycosis is an emerging angio-invasive infection caused by Mucorales that presents unacceptable mortality rates. Iron uptake has been related to mucormycosis, since serum iron availability predisposes the host to suffer this infection. In addition, iron uptake has been described as a limiting factor that determines virulence in other fungal infections, becoming a promising field to study virulence in Mucorales. Here, we identified a gene family of three ferroxidases in Mucor circinelloides, fet3a, fet3b and fet3c, which are overexpressed during infection in a mouse model for mucormycosis, and their expression in vitro is regulated by the availability of iron in the culture media and the dimorphic state. Thus, only fet3a is specifically expressed during yeast growth under anaerobic conditions, whereas fet3b and fet3c are specifically expressed in mycelium during aerobic growth. A deep genetic analysis revealed partially redundant roles of the three genes, showing a predominant role of fet3c, which is required for virulence during in vivo infections, and shared functional roles with fet3b and fet3c during vegetative growth in media with low iron concentration. These results represent the first described functional specialization of an iron uptake system during fungal dimorphism.

Mucormycosis in Children: Review and Recommendations for Management

Mucormycosis represents the third most common invasive fungal infection in children, and recent studies have suggested a rising incidence. Its case fatality rate is high, especially for neonates. Clinical presentation is influenced by underlying risk factors; associations with immunosuppression, neutropenia, diabetes, and prematurity have been described. It has been implicated in several hospital outbreaks. Diagnosis requires a high index of suspicion and evaluation with histopathology, culture, and, increasingly, molecular identification. Surgical debridement and antifungal therapies are the cornerstone for combatting invasive mucormycosis. However, the severity and relative rarity of this disease make comparative clinical trials for evaluating antifungal therapies in children difficult to conduct. Hence, therapeutic decisions are derived mainly from retrospective case series, in vitro data, and animal models. In this review, we summarize the literature on the epidemiology and diagnosis of this invasive fungal infection and provide suggestions on the management of mucormycosis in children.

Cutaneous Mucormycosis Following a Bullous Pemphigoid Flare in a Chronic Lymphocytic Leukemia Patient on Ibrutinib

While the recent development of novel therapeutics in oncology, such as small molecule kinase inhibitors (SMKIs), has enabled our ability to target disease-specific molecular pathways, the prolonged impact of these agents on the immune system and infectious risk remains to be seen. We present a 68-year-old male with refractory chronic lymphocytic leukemia (CLL) on ibrutinib monotherapy for 3 years who developed extensive cutaneous mucormycosis following a severe bullous pemphigoid (BP) flare. He received amphotericin B for 4 weeks and was continued on posaconazole with resolution of his mucormycosis infection. Consistent with a growing evidence of literature identifying opportunistic fungal infections in patients on ibrutinib therapy, providers should be cognizant of medical comorbidities that may predispose to such infections and explore methods of prevention before starting ibrutinib and other SMKIs.

Spotlight on isavuconazole in the treatment of invasive aspergillosis and mucormycosis: design, development, and place in therapy

In recent decades, important advances have been made in the diagnosis and treatment of invasive aspergillosis (IA) and mucormycosis. One of these advances has been the introduction of isavuconazole, a second-generation broad spectrum triazole with a favorable pharmacokinetic and safety profile and few drug–drug interactions. Phase III trials in patients with IA and mucormycosis demonstrated that isavuconazole has similar efficacy to voriconazole for the treatment of IA (SECURE trial) and liposomal amphotericin B for the treatment of mucormycosis (VITAL trial with subsequent case–control analysis) and a favorable safety profile with significantly fewer ocular, hepatobiliary, and skin and soft tissue adverse events compared to voriconazole. As a result, recent IA guidelines recommend isavuconazole (together with voriconazole) as gold standard treatment for IA in patients with underlying hematological malignancies. In contrast to liposomal amphotericin B, isavuconazole can be safely administered in patients with reduced renal function and is frequently used for the treatment of mucormycosis in patients with reduced renal function. Updated guidelines on mucormycosis are needed to reflect the current evidence and give guidance on the use of isavuconazole for mucormycosis. Studies are needed to evaluate the role of isavuconazole for 1) anti-mold prophylaxis in high-risk patients, 2) salvage treatment for IA and mucormycosis, and 3) treatment for other mold infections such as Scedosporium apiospermum.

Isavuconazole: A Promising Salvage Therapy for Invasive Mucormycosis

A patient with invasive mucormycosis whose disease progresses despite optimal treatment including surgical debridement, intravenous (IV) amphotericin B, and control of the predisposing factors can be clinically challenging. We report a case of a 67-year-old Caucasian man with invasive mucormycosis that did not respond to first-line treatment. He was subsequently started on isavuconazole in addition to amphotericin B. The patient’s disease progression stopped; he then received IV amphotericin B for 50 days and isavuconazole for four months. Repeated magnetic resonance imaging (MRI) of the orbit and face nine months later, while off the antifungal medications, showed stable disease. This outcome is promising for patients with invasive mucormycosis who are either intolerant to amphotericin B or do not respond favorably to it.

Mucor circinelloides: Growth, Maintenance, and Genetic Manipulation

Mucor circinelloides is a fungus that belongs to the order Mucorales. It grows as mold in the environment and can cause mucormycosis, a potentially fatal infection in immunocompromised patients. M. circinelloides is a biodiesel producer and serves as a model organism for studying several biological processes, such as light responses and RNA interference-mediated gene silencing. Over the past decade, the increasing number of molecular tools has also allowed us to manipulate the genome of this fungus. This article outlines the fundamental protocols for the in vitro growth, maintenance, and genetic manipulation of M. circinelloides in the laboratory. © 2018 by John Wiley & Sons, Inc.

Outbreak of Invasive Wound Mucormycosis in a Burn Unit Due to Multiple Strains of Mucor circinelloides f. circinelloides Resolved by Whole-Genome Sequencing

Mucorales are ubiquitous environmental molds responsible for mucormycosis in diabetic, immunocompromised, and severely burned patients. Small outbreaks of invasive wound mucormycosis (IWM) have already been reported in burn units without extensive microbiological investigations. We faced an outbreak of IWM in our center and investigated the clinical isolates with whole-genome sequencing (WGS) analysis. We analyzed M. circinelloides isolates from patients in our burn unit (BU1, Hôpital Saint-Louis, Paris, France) together with nonoutbreak isolates from Burn Unit 2 (BU2, Paris area) and from France over a 2-year period (2013 to 2015). A total of 21 isolates, including 14 isolates from six BU1 patients, were analyzed by whole-genome sequencing (WGS). Phylogenetic classification based on de novo assembly and assembly free approaches showed that the clinical isolates clustered in four highly divergent clades. Clade 1 contained at least one of the strains from the six epidemiologically linked BU1 patients. The clinical isolates were specific to each patient. Two patients were infected with more than two strains from different clades, suggesting that an environmental reservoir of clonally unrelated isolates was the source of contamination. Only two patients from BU1 shared one strain, which could correspond to direct transmission or contamination with the same environmental source. In conclusion, WGS of several isolates per patients coupled with precise epidemiological data revealed a complex situation combining potential cross-transmission between patients and multiple contaminations with a heterogeneous pool of strains from a cryptic environmental reservoir.

Invasive wound mucormycosis (IWM) is a severe infection due to environmental molds belonging to the order Mucorales. Severely burned patients are particularly at risk for IWM. Here, we used whole-genome sequencing (WGS) analysis to resolve an outbreak of IWM due to Mucor circinelloides that occurred in our hospital (BU1). We sequenced 21 clinical isolates, including 14 from BU1 and 7 unrelated isolates, and compared them to the reference genome (1006PhL). This analysis revealed that the outbreak was mainly due to multiple strains that seemed patient specific, suggesting that the patients were more likely infected from a pool of diverse strains from the environment rather than from direct transmission among them. This study revealed the complexity of a Mucorales outbreak in the settings of IWM in burn patients, which has been highlighted based on WGS combined with careful sampling.

Mucormycosis: Battle with the Deadly Enemy over a Five-Year Period in India

Mucormycosis is an emerging opportunistic fungal infection. Increasing immunocompromization, widespread use of antibacterial and antifungal agents (such as voriconazole prophylaxis), carcinomas, transplantation and lifestyle diseases such as diabetes are the main contributors to this situation. The predominant clinical manifestations of mucormycosis vary from host to host, with rhino-orbital-cerebral, pulmonary, cutaneous, and gastrointestinal infections being the most common. In India, the prevalence of mucormycosis is approximately 0.14 cases/1000 population, which is about 70 times the worldwide-estimated rate for mucormycosis. The present study was undertaken over a period of five years (January 2009-December 2014) to determine the prevalence of mucormycosis. The samples suspected of mucormycosis were examined by direct KOH wet mount and cultured on Sabouraud's dextrose agar without actidione and on blood agar as per standard mycological techniques. Histopathological correlation was done for most of the cases. Antifungal susceptibility testing was performed by the EUCAST reference method. We identified a total of 82 cases of mucormycosis out of a total of 6365 samples received for mycological culture and examination during the said time period. Out of these, 56 were male patients and 27 were females. Most common presentation was rhino-orbito-cerebral (37), followed by cutaneous (25), pulmonary (14), oral cavity involvement (4) and gastrointestinal (2). The most common risk factors were diabetes and intramuscular injections. The fungi isolated were Rhizopus arrhizus (17), Apophysomyces variabilis (12), R. microsporus (9), Lichtheimia ramosa (8), Saksenaea erythrospora (5), Syncephalastrum racemosus (4), R. homothallicus (2), Rhizomucor pusillus (1), Mucor irregularis (1) and A. elegans (1). The mainstay of the treatment was amphotericin B, along with extensive surgical debridement whenever feasible. Most of the patients (50) recovered, but 25 died. The rest of the patients left against medical advice. "Nip in the Bud" should be the mantra for clinicians/surgeons for a favorable prognosis. Early diagnosis, prompt institution of appropriate antifungal therapy, surgical debridement whenever necessary, knowledge of risk factors and their timely reversal is the key for management.

Robust Phagocyte Recruitment Controls the Opportunistic Fungal Pathogen Mucor circinelloides in Innate Granulomas In Vivo

Mucormycosis is an emerging fungal infection with extremely high mortality rates in patients with defects in their innate immune response, specifically in functions mediated through phagocytes. However, we currently have a limited understanding of the molecular and cellular interactions between these innate immune effectors and mucormycete spores during the early immune response. Here, the early events of innate immune recruitment in response to infection by Mucor circinelloides spores are modeled by a combined in silico modeling approach and real-time in vivo microscopy. Phagocytes are rapidly recruited to the site of infection in a zebrafish larval model of mucormycosis. This robust early recruitment protects from disease onset in vivoIn silico analysis identified that protection is dependent on the number of phagocytes at the infection site, but not the speed of recruitment. The mathematical model highlights the role of proinflammatory signals for phagocyte recruitment and the importance of inhibition of spore germination for protection from active fungal disease. These in silico data are supported by an in vivo lack of fungal spore killing and lack of reactive oxygen burst, which together result in latent fungal infection. During this latent stage of infection, spores are controlled in innate granulomas in vivo Disease can be reactivated by immunosuppression. Together, these data represent the first in vivo real-time analysis of innate granuloma formation during the early stages of a fungal infection. The results highlight a potential latent stage during mucormycosis that should urgently be considered for clinical management of patients.IMPORTANCE Mucormycosis is a dramatic fungal infection frequently leading to the death of patients. We know little about the immune response to the fungus causing this infection, although evidence points toward defects in early immune events after infection. Here, we dissect this early immune response to infectious fungal spores. We show that specialized white blood cells (phagocytes) rapidly respond to these spores and accumulate around the fungus. However, we demonstrate that the mechanisms that enable phagocytes to kill the fungus fail, allowing for survival of spores. Instead a cluster of phagocytes resembling an early granuloma is formed around spores to control the latent infection. This study is the first detailed analysis of early granuloma formation during a fungal infection highlighting a latent stage that needs to be considered for clinical management of patients.

Mucormycosis: Early Identification of a Deadly Fungus [Formula: see text]

Mucormycosis is a rare invasive fungal infection that affects immunocompromised patients and is fatal when not identified and treated early. Diagnosis is often delayed as the symptoms are nonspecific and frequently mimic other common diseases. Pediatric patients with cancer are at risk for the infection; however, there is limited research that applies directly to the pediatric population. An understanding of the risk factors and clinical presentation of mucormycosis is crucial for the pediatric oncology provider to initiate the workup and provide prompt treatment. The gold standard for diagnosing mucormycosis is biopsy; however, the use of polymerase chain reaction is a novel tool that is being investigated. The mainstays of treatment are antifungal medications, surgery, and reversal of predisposing risk factors, although, new therapies are also emerging. This article will review the pathophysiology, clinical manifestations, and diagnostics of mucormycosis and will discuss current treatment and management strategies for the pediatric oncology clinician to allow for timely diagnosis and intervention to optimize patient outcomes.

Near-fatal mucormycosis post-double lung transplant presenting as uncontrolled upper gastrointestinal haemorrhage

Invasive fungal infections in immunosuppressed transplant patients are associated with significant morbidity and mortality. We present a case of splenic mucormycosis post-double lung transplant, presenting as uncontrolled near-fatal upper gastrointestinal haemorrhage, to remind clinicians of the need to consider pre-transplant invasive fungal infection risk factors if an unexpected fungal infection arises in the post-transplant period. This case also highlights the valuable contribution of molecular technology for fungal identification but also the need for clinical correlation.

FungiScope™ -Global Emerging Fungal Infection Registry

Rare invasive fungal diseases (IFD) are challenging for the treating physicians because of their unspecific clinical presentation, as well as the lack of standardised diagnostic and effective treatment strategies. Late onset of treatment and inappropriate medication is associated with high mortality, thus, urging the need for a better understanding of these diseases. The purpose of FungiScope^™ is to continuously collect clinical information and specimens to improve the knowledge on epidemiology and eventually improve patient management of these orphan diseases. FungiScope^™ was founded in 2003, and today, collaborators from 66 countries support the registry. So far, clinical data of 794 cases have been entered using a web-based approach. Within the growing network of experts, new collaborations developed, leading to several publications of comprehensive analyses of patient subgroups identified from the registry. Data extracted from FungiScope^™ have also been used as the sole control group for the approval of a new antifungal drug. Due to the rarity of these diseases, a global registry is an appropriate method of pooling the scarce and scattered information. Joining efforts across medical specialities and geographical borders is key for researching rare IFD. Here, we describe the structure and management of the FungiScope^™ registry.

Mucormycosis in Iran: A six-year retrospective experience

Mucormycosis is a devastating infection caused by Mucoralean fungi (Mucormycotina, Mucorales). Data concerning the global epidemiology of mucormycosis are scarce and little is known about the characteristics of mucormycosis in Iran. In this study, we aimed to understand the distribution of this infection in Iran retrospectively and to ascertain whether the patterns of infection are associated with specific host factors or not. A total of 208 cases were included in this study occurring during 2008-2014 and were validated according to (EORTC/MSG) criteria. A rising trend as significant increase from 9.7% in 2008 to 23.7% in 2014 was observed. The majority of patients were female (51.4%) with median age of 50 and the infections were seen mostly in autumn season (39.4%). Diabetes mellitus (75.4%) was the most common underlying condition and sinus involvement (86%) was the mostly affected site of infection. Amphotericin B (AmB) was the drug of choice for the majority of cases. Sixty four isolates did not show any growth in the lab and only 21 cases were evaluated by ITS sequencing, among them; Rhizopus arrhizus var. arrhizus was the dominant species. Considering the high mortality rate of mucormycosis, early and accurate diagnosis, with the aid of molecular methods may provide accurate treatments and improve the survival rate. Therefore, increased monitoring and awareness of this life-threatening disease is critical.

Pulmonary Mucormycosis in Chronic Lymphocytic Leukemia and Neutropenia

Pulmonary mucormycosis is a rare life-threatening fungal infection associated with high mortality. We present the case of a 61-year-old man with history of chronic lymphocytic leukemia who presented with fever and cough, eventually diagnosed with pulmonary mucormycosis after right lung video-assisted thoracoscopic surgery. The patient was successfully treated with amphotericin B and right lung pneumonectomy; however, he later died from left lung pneumonia.

Detection of mucormycetes and other pathogenic fungi in formalin fixed paraffin embedded and fresh tissues using the extended region of 28S rDNA

Molecular methods of detection based on DNA-sequencing of the internal transcribed spacer 1 and 2 (ITS1 and ITS2) or 5΄ end region of 28S (D1-D2 region) of ribosomal RNA gene (rDNA) have been used extensively for molecular identification and detection of fungal infections. However, these regions are not always informative for identification of mucormycetes and other rare fungal pathogens as they often contain large introns, heterogenic regions, and/or cannot be PCR-amplified using broad range fungal PCR primers. In addition, because of the difficulties of recovering intact fungal DNA from human specimens, smaller regions of DNA are more useful for the direct detection of fungal DNA in tissues and fluids. In this study, we investigated the utility of 12F/13R PCR primers targeting a 200-230 bp region of the extended 28S region of rDNA for molecular identification of fungal DNA in formalin fixed paraffin embedded tissues and other clinical specimens. We demonstrated that this region can be successfully used for identification of all genera and some species of clinically relevant mucormycetes, as well as other medically important fungi, such as Aspergillus, Fusarium, Coccidioides, and Cryptococcus. We also demonstrated that PCR amplification and direct sequencing of the extended 28S region of rDNA was more sensitive compared to targeting the ITS2 region, as we were able to detect and identify mucormycetes and other fungal pathogens in tissues from patients with histopathological and/or culture evidence of fungal infections that were negative with PCR using ITS-specific primers.

Approach to skin and soft tissue infections in non-HIV immunocompromised hosts

PURPOSE OF REVIEW

Skin and soft tissue infections are frequent contributors to morbidity and mortality in the immunocompromised host. This article reviews the changing epidemiology and clinical manifestations of the most common cutaneous pathogens in non-HIV immunocompromised hosts, including patients with solid organ transplants, stem cell transplants, solid tumors, hematologic malignancies, and receiving chronic immunosuppressive therapy for inflammatory disorders.

RECENT FINDINGS

Defects in the innate or adaptive immune response can predispose the immunocompromised host to certain cutaneous infections in a predictive fashion. Cutaneous lesions in patients with neutrophil defects are commonly due to bacteria, Candida, or invasive molds. Skin lesions in patients with cellular or humoral immunodeficiencies can be due to encapsulated bacteria, Nocardia, mycobacteria, endemic fungal infections, herpesviruses, or parasites. Skin lesions may reflect primary inoculation or, more commonly, disseminated infection. Tissue samples for microscopy, culture, and histopathology are critical to making an accurate diagnosis given the nonspecific and heterogeneous appearance of these skin lesions due to a blunted immune response.

SUMMARY

As the population of non-HIV immunosuppressed hosts expands with advances in medical therapies, the frequency and variety of cutaneous diseases in these hosts will increase.

Primary Cutaneous Mucormycosis in a Trauma Patient with Morel-Lavallée Lesion

Mucormycosis is an aggressive fungal infection caused by zygomycetes from the order of Mucorales. Immunocompromised patients or patients with comorbidities are susceptible to this infection. There are many forms of mucormycosis such as rhino-orbito-cerebral, cutaneous, gastrointestinal, and pulmonary. Cutaneous mucormycosis is rare in trauma patients with no comorbidities. Morel-Lavallée lesions are rare degloving injuries in trauma patients. We report a case of cutaneous mucormycosis in a trauma patient with the Morel-Lavallée lesions.

Primary Oral Mucormycosis Due to Rhizopus microsporus after Allogeneic Stem Cell Transplantation

We herein report a rare case of oral mucormycosis following allogeneic hematopoietic stem cell transplantation. Oral mucormycosis due to Rhizopus microsporus manifested as localized left buccal mucositis with a 1-cm black focus before neutrophil recovery. Combination therapy with liposomal amphotericin B was initiated and surgical debridement was performed; however, the patient died due to progressive generalized mucormycosis. Considerable attention needs to be paid to the diagnosis and management of oral mucormycosis in post-transplant patients, thereby suggesting the importance of fully understanding the risk factors.

A Young, Immunocompetent Woman with Small Bowel and Hepatic Mucormycosis Successfully Treated with Aggressive Surgical Debridements and Antifungal Therapy

A 24-year-old woman with coeliac disease and transient neutropenia developed mucormycosis with extensive involvement of the liver and small intestine. She was successfully treated with aggressive surgical debridements and long-term antifungal therapy with liposomal amphotericin B and posaconazole.

Seasonal clustering of sinopulmonary mucormycosis in patients with hematologic malignancies at a large comprehensive cancer center

Background

Invasive Mucorales infections (IMI) lead to significant morbidity and mortality in immunocompromised hosts. The role of season and climatic conditions in case clustering of IMI remain poorly understood.

Methods

Following detection of a cluster of sinopulmonary IMIs in patients with hematologic malignancies, we reviewed center-based medical records of all patients with IMIs and other invasive fungal infections (IFIs) between January of 2012 and August of 2015 to assess for case clustering in relation to seasonality.

Results

A cluster of 7 patients were identified with sinopulmonary IMIs (Rhizopus microsporus/azygosporus, 6; Rhizomucor pusillus, 1) during a 3 month period between June and August of 2014. All patients died or were discharged to hospice. The cluster was managed with institution of standardized posaconazole prophylaxis to high-risk patients and patient use of N-95 masks when outside of protected areas on the inpatient service. Review of an earlier study period identified 11 patients with IMIs of varying species over the preceding 29 months without evidence of clustering. There were 9 total IMIs in the later study period (12 month post-initial cluster) with 5 additional cases in the summer months, again suggesting seasonal clustering. Extensive environmental sampling did not reveal a source of mold. Using local climatological data abstracted from National Centers for Environmental Information the clusters appeared to be associated with high temperatures and low precipitation.

Conclusions

Sinopulmonary Mucorales clusters at our center had a seasonal variation which appeared to be related to temperature and precipitation. Given the significant mortality associated with IMIs, local climatic conditions may need to be considered when considering center specific fungal prevention and prophylaxis strategies for high-risk patients.

The mucormycete-host interface

Mucormycosis is a fungal infection with fulminant angioinvasion leading to high morbidity and mortality in susceptible individuals. The major predisposing conditions are uncontrolled diabetes, neutropenia, malignancies, receipt of a transplant and traumatic injury [1]. Over the past decade, mucormycosis has become an emerging fungal infection due to the increase in patient groups presenting with these pre-disposing conditions and our medical advances in diagnosing the infection [2-4]. Yet, we currently lack clinical interventions to treat mucormycosis effectively. This in turn is due to a lack of understanding of mucormycosis pathogenesis. Here, we discuss our current understanding of selected aspects of interactions at the mucormycete-host interface. We will highlight open questions that might guide future research directions for investigations into the pathogenesis of mucormycosis and potential innovative therapeutic approaches.

Intrinsic short-tailed azole resistance in mucormycetes is due to an evolutionary conserved aminoacid substitution of the lanosterol 14α-demethylase

Mucormycoses are emerging and potentially lethal infections. An increase of breakthrough infections has been found in cohorts receiving short-tailed azoles prophylaxis (e.g. voriconazole (VCZ)). Although VCZ is ineffective in vitro and in vivo, long-tailed triazoles such as posaconazole remain active against mucormycetes. Our goal was to validate the molecular mechanism of resistance to short-tailed triazoles in Mucorales. The paralogous cytochrome P450 genes (CYP51 F1 and CYP51 F5) of Rhizopus arrhizus, Rhizopus microsporus, and Mucor circinelloides were amplified and sequenced. Alignment of the protein sequences of the R. arrhizus, R. microsporus, and M. circinelloides CYP51 F1 and F5 with additional Mucorales species (n = 3) and other fungi (n = 16) confirmed the sequences to be lanosterol 14α-demethylases (LDMs). Sequence alignment identified a pan-Mucorales conservation of a phenylalanine129 substitution in all CYP51 F5s analyzed. A high resolution X-ray crystal structure of Saccharomyces cerevisiae LDM in complex with VCZ was used for generating a homology model of R. arrhizus CYP51 F5. Structural and functional knowledge of S. cerevisiae CYP51 shows that the F129 residue in Mucorales CYP51 F5 is responsible for intrinsic resistance of Mucorales against short-tailed triazoles, with a V to A substitution in Helix I also potentially playing a role.

Disseminated mucormycosis: A sinister cause of neutropenic fever syndrome

A 15 year old girl presented with complaints of prolonged fever and recurrent episodes of hemoptysis. Initial investigation showed pancytopenia and radiological imaging was suggestive of necrotizing pneumonia. Subsequently, mucor was isolated from bronchoalveolar lavage fluid, but even on appropriate medications her condition kept deteriorating. She had multiple bouts of hemoptysis and a repeat imaging of chest showed dissemination of mucormycosis to pulmonary vein and heart. Bone marrow biopsy identified acute lymphoblastic leukemia (ALL) as the cause of pancytopenia. She was planned for bronchial artery embolization and chemotherapy for ALL, but consent was not given and she left our institute against medical advice. Our case highlights the importance of keeping a high index of suspicion for disseminated mucormycosis in neutropenic patients, as any delay in diagnosis and treatment could have grave consequences.

Rare fungal infectious agents: a lurking enemy

In the expanding population of immunocompromised patients and those treated in intensive care units, rare fungal infectious agents have emerged as important pathogens, causing invasive infections associated with high morbidity and mortality. These infections may present either as de novo or as breakthrough invasive infections in high-risk patients with hematologic malignancies receiving prophylactic or empirical antifungal therapy or in patients with central venous catheters. Diagnosis and treatment are challenging. Physicians should have a high index of suspicion because early diagnosis is of paramount importance. Conventional diagnostic methods such as cultures and histopathology are still essential, but rapid and more specific molecular techniques for both detection and identification of the infecting pathogens are being developed and hopefully will lead to early targeted treatment. The management of invasive fungal infections is multimodal. Reversal of risk factors, if feasible, should be attempted. Surgical debridement is recommended in localized mold infections. The efficacy of various antifungal drugs is not uniform. Amphotericin B is active against most yeasts, except Trichosporon, as well as against Mucorales, Fusarium, and some species of Paecilomyces and dimorphic fungi. The use of voriconazole is suggested for the treatment of trichosporonosis and scedosporiosis. Combination treatment, though recommended as salvage therapy in some infections, is controversial in most cases. Despite the use of available antifungals, mortality remains high. The optimization of molecular-based techniques, with expansion of reference libraries and the possibility for direct detection of resistance mechanisms, is awaited with great interest in the near future. Further research is necessary, however, in order to find the best ways to confront and destroy these lurking enemies.

Innate and Adaptive Immunity to Mucorales

Mucormycosis is an invasive fungal infection characterised by rapid filamentous growth, which leads to angioinvasion, thrombosis, and tissue necrosis. The high mortality rates (50-100%) associated with mucormycosis are reflective of not only the aggressive nature of the infection and the poor therapeutics currently employed, but also the failure of the human immune system to successfully clear the infection. Immune effector interaction with Mucorales is influenced by the developmental stage of the mucormycete spore. In a healthy immune environment, resting spores are resistant to phagocytic killing. Contrarily, swollen spores and hyphae are susceptible to damage and degradation by macrophages and neutrophils. Under the effects of immune suppression, the recruitment and efficacy of macrophage and neutrophil activity against mucormycetes is considerably reduced. Following penetration of the endothelial lining, Mucorales encounter platelets. Platelets adhere to both mucormycete spores and hyphae, and exhibit germination suppression and hyphal damage capacity in vitro. Dendritic cells are activated in response to Mucorales hyphae only, and induce adaptive immunity. It is crucial to further knowledge regarding our immune system's failure to eradicate resting spores under intact immunity and inhibit fungal growth under immunocompromised conditions, in order to understand mucormycosis pathogenicity and enhance therapeutic strategies for mucormycosis.

Diagnostic Imaging and Invasive Fungal Diseases in Children

Invasive fungal disease (IFD) is a life-threatening condition, especially in immunocompromised children. The role of diagnostic imaging in children at risk for an IFD is multifactorial, including initially detecting it, evaluating for dissemination of infection beyond the primary site of disease, monitoring the response to antifungal therapy, and assessing for potential relapse. The objective of this review was to synthesize the published literature relevant to the use of various imaging modalities for the diagnosis and management of IFD in children.

Diagnosis and Treatment of Mucormycosis in Patients withHematological Malignancies［Translated Article］

The risk of invasive fungal infections (IFIs) is extremely high in patients with hematological malignancies due to the prolonged and profound neutropenia and immunosuppression after chemotherapy and hematopoietic stem cell transplantation. There has been increasing interest in mucormycosis despite its relatively uncommon occurrence, because occasional breakthrough infections have been observed under anti-Aspergillus prophylaxis. The aggressive nature of mucormycosis easily leads to high mortality because of delays in diagnosis and incorrect treatment decisions, which are due in part to lack of adjunctive diagnostic tools and having similar clinical and radiological features with invasive aspergillosis. The only currently available antifungals against Mucorales in Japan are amphotericin B formulations. Thus, comprehensive therapeutic strategies, including surgery, should be considered to achieve a successful outcome.

Rhino-orbito-cerebral mucormycosis: recovery against the odds

A 22-year-old woman presented with diabetic ketoacidosis, acute right eye blindness and complete ophthalmoplegia. Despite early suspicion and treatment for rhino-orbito-cerebral mucormycosis, her extensive spread of infection led to right internal carotid artery occlusion and cavernous sinus thrombosis, right-sided cerebral watershed infarctions and large abscesses in her right cerebellum, temporal lobe and pons. She underwent surgical removal of her right eye, paranasal sinuses, maxilla and palate, suboccipital craniectomy and shunting for hydrocephalus. Despite the grave prognosis, she has gradually improved and has remained on antifungal treatment for the 18 months since presentation. We discuss the factors that may have influenced her recovery. The case highlights the aggressive nature of rhino-orbito-cerebral mucormycosis, the need for multiple surgeries and the ethical issues in managing such patients.

Bedside diagnostics in dermatology: Viral, bacterial, and fungal infections

Viral, bacterial, and fungal infections are frequently encountered in clinical practice, resulting in numerous cutaneous manifestations. Although diagnosis of these infections has changed over time because of technological advancements, such as polymerase chain reaction, bedside diagnostic techniques still play an important role in diagnosis and management, enabling rapid and low-cost diagnosis and implementation of appropriate therapies. This 2-part article will review both common and infrequent uses of bedside diagnostic techniques that dermatologists can incorporate into daily practice. This article examines the utility of bedside tests for the diagnosis of viral, bacterial, and fungal infections. The second article in this series reviews the use of bedside diagnostics for parasitic and noninfectious disorders.