Epidemiology and clinical manifestations of mucormycosis

Fatal renal mucormycosis with Apophysomyces elegans in an apparently healthy male

Mucor is an angioinvasive fungus that was reported mainly in immunocompromised patients. It usually presents as rhino-orbital, pulmonary, gastrointestinal, and disseminated disease. Isolated renal mucormycosis is an extremely rare infection in immunocompetent patients and is associated with high fatality rate. Early diagnosis, prompt antifungal treatment, and surgery give the patient the best chance for cure and survival. We describe herein a case of renal zygomycosis caused by Apophysomyces elegans (A. elegans) in an immunocompetent host. To the best of our knowledge, this is the first case of renal A. elegans to be reported from Qatar and the Middle East.

Intracranial brain parenchymal spread of mucormycosis through olfactory tract: a diffusion-weighted imaging-based concept

Mucormycosis is an opportunistic fungal infection involving among others the paranasal sinuses, nasal fossa and brain parenchyma. Mucor can invade the brain parenchyma by either contiguous spread from the paranasal sinuses or through vascular invasion. We report a case of fatal rhino-cerebral mucormycosis in whom cytotoxic edema at magnetic resonance diffusion-weighted imaging was symmetrically restricted to both neocortical and paleocortical primary areas of olfactory projection at earliest phase of the disease process. Shortly later tissue damage extended into the whole brain. This undescribed observation raised the hypothesis of preferential way of brain invasion by Mucor through the olfactory tract.

Isavuconazole: Mechanism of Action, Clinical Efficacy, and Resistance

Increasing incidence of invasive fungal infections combined with a growing population of immunocompromised hosts has created a rising need for antifungal agents. Isavuconazole, a second-generation broad-spectrum triazole with activity against yeasts, dimorphic fungi, and molds, has a favorable safety profile and predictable pharmacokinetics. Patients typically tolerate isavuconazole well with fewer drug-drug interactions. Clinical trials have found it to be noninferior to voriconazole for invasive aspergillosis, an alternative therapy for salvage treatment of mucormycosis, and suitable for stepdown therapy with invasive candidiasis. Cross-resistance with other triazoles is common. More studies are needed to determine the role of isavuconazole in anti-mold prophylaxis in high-risk patients.

Rhinocerebral Mucormycosis: A Ten-Year Single Centre Case Series

Introduction

Rhinocerebral mucormycosis (RCM) is a rare, frequently lethal, opportunistic infection of the paranasal sinuses and brain caused by fungi of the Mucoracea family. The overall global incidence is low, with the condition most commonly found in India and the Middle East. Early diagnosis and aggressive treatment are essential. Overall mortality is high; reported rates range from 25-60%. Its infrequent presentation can pose both diagnostic and therapeutic challenges for centers not familiar with the condition.

Objective

We aimed to evaluate patient demographics, clinical presentation, diagnosis, management, and the complications of this uncommon condition.

Methods

We carried out a retrospective case-series analysis of all patients with a confirmed diagnosis of RCM presenting to a single tertiary-level hospital between 2000-2010. Hospital patient records were used to attain the specific clinical details for each case.

Results

A total of nine patients (eight males and one female) were diagnosed with RCM during this period. All patients had diabetes mellitus; the mean age was 58.2 years. The most common presenting features were foul-smelling blood-stained rhinorrhoea (100%), nasal congestion (100%), reduced visual acuity (89%), and hard palate ulceration (67%). Two patients had a cerebral abscess at presentation; two patients had skull base erosions with associated cranial nerve palsies. All patients received systemic amphotericin B and surgical debridement. The overall mortality rate was 78%.

Conclusions

Rhinocerebral mucormycosis is a notoriously difficult infection to treat. Our case series demonstrates how patients often present late with a disease that has already spread beyond the paranasal sinuses. Despite treatment with antifungals and extensive surgical debridement, mortality remains high.

The Postmortem Features of Mucormycosis

Mucormycosis is a rare and severe invasive fungal infection caused by ubiquitous fungi of the order Mucorales. Infection often occurs in immunocompromised hosts and includes cutaneous, pulmonary, gastrointestinal, rhinocerebral, and disseminated forms of disease. Although the clinical characteristics of mucormycosis are well established, infection can be difficult to diagnose antemortem, resulting in frequent postmortem diagnoses. Despite this, the gross appearance of mucormycosis at autopsy has not been well described. In the present report we illustrate the gross and histologic findings in four autopsy cases of mucormycosis, including one case of pulmonary disease and three cases of disseminated mucormycosis with cerebral, pulmonary, hepatic, renal, and gastrointestinal involvement. In all cases autopsy examination demonstrated characteristic hemorrhagic infarcts with a targetoid appearance in the affected organs. These findings are secondary to fungal angioinvasion with subsequent thrombosis and tissue necrosis. Mucormycosis should be suspected at autopsy when these characteristic infarcts are identified within the proper clinical context, and a high suspicion for atypical infections should be maintained postmortem in immunosuppressed patients.

Gastrointestinal mucormycosis due to Rhizopus microsporus following Streptococcus pyogenes toxic shock syndrome in an HIV patient: a case report

Background

Gastrointestinal (GI) mucormycosis is a rare and often deadly form of mucormycosis. Delayed diagnosis can lead to an increased risk of death. Here, we report a case of GI mucormycosis following streptococcal toxic shock syndrome in a virologically suppressed HIV-infected patient.

Case presentation

A 25-year-old Thai woman with a well-controlled HIV infection and Grave’s disease was admitted to a private hospital with a high-grade fever, vomiting, abdominal pain, and multiple episodes of mucous diarrhea for 3 days. On day 3 of that admission, the patient developed multiorgan failure and multiple hemorrhagic blebs were observed on all extremities. A diagnosis of streptococcal toxic shock was made before referral to Siriraj Hospital – Thailand’s largest national tertiary referral center. On day 10 of her admission at our center, she developed feeding intolerance and bloody diarrhea due to bowel ischemia and perforation. Bowel resection was performed, and histopathologic analysis of the resected bowel revealed acute suppurative transmural necrosis and vascular invasion with numerous broad irregular branching non-septate hyphae, both of which are consistent with GI mucormycosis. Peritoneal fluid fungal culture grew a grayish cottony colony of large non-septate hyphae and spherical sporangia containing ovoidal sporangiospores. A complete ITS1–5.8S-ITS2 region DNA sequence analysis revealed 100% homology with Rhizopus microsporus strains in GenBank (GenBank accession numbers KU729104 and AY803934). As a result, she was treated with liposomal amphotericin B. However and in spite of receiving appropriate treatment, our patient developed recurrent massive upper GI bleeding from Dieulafoy’s lesion and succumbed to her disease on day 33 of her admission.

Conclusion

Diagnosis of gastrointestinal mucormycosis can be delayed due to a lack of well-established predisposing factors and non-specific presenting symptoms. Further studies in risk factors for abdominal mucormycosis are needed.

Identification of Mucor circinelloides antigens recognized by sera from immunocompromised infected mice

BACKGROUND

Mucor circinelloides is an opportunistic fungus capable of causing mucormycosis, a highly aggressive infection of quick spreading. Besides, it also has a high mortality rate due to late diagnosis and difficult treatment.

AIMS

In this study we have identified the most immunoreactive proteins of the secretome and the total protein extract of M. circinelloides using sera from immunocompromised infected mice.

METHODS

The proteins of the secretome and the total extract were analyzed by two-dimensional electrophoresis and the most immunoreactive antigens were detected by Western Blot, facing the sera of immunocompromised infected mice to the proteins obtained in both extracts of M. circinelloides.

RESULTS

Seven antigens were detected in the secretome extract, and two in the total extract, all of them corresponding only to three proteins. The enzyme enolase was detected in both extracts, while triosephosphate isomerase was detected in the secretome, and heat shock protein HSS1 in the total extract.

CONCLUSIONS

In this work the most immunoreactive antigens of the secretome and the total extract of M. circinelloides were identified. The identified proteins are well known fungal antigens and, therefore, these findings can be useful for future research into alternatives for the diagnosis and treatment of mucormycosis.

Mucormycosis: A rare entity with rising clinical presentation in immunocompromised hosts

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It is a case study of an immunocompromised patients affected by Mucormycosis which is - a profoundly mortal fungal infection.

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In order to restore the function, enhance the cosmetic appearance and quality of life of the patient, surgical intervention is often necessary to correct the various pathologies affecting the patients.

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This paper highlights the significance of prompt diagnosis and urgent treatment, especially among high-risk patients, of this potentially lethal phenomenon and the surgical procedure undertaken to remove the disease afecting the person and improve the patient's overall health.

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The management of our patient demonstrates the need for an early visual identification and diagnosis approach that is multidisciplinary, multi-factorial and multi-faceted.

Introduction

Mucormycosis is a rare, rapidly progressive and a fulminant, life-threatening, opportunistic infection. Although it most commonly manifests in diabetic patients, its presence in other immunologically compromised patients cannot be ruled out. Its etiology is saprophytic fungal organisms, with rhizopus being the most common causative organism. Clinically the disease is marked by a partial loss of neurological function and a progressive necrosis due to the invasion of the organisms into the blood vessels causing a lack of blood supply. The disease may progress to involve the cranium thereby increasing the mortality rate. The first line of management in mucormycosis is antifungal therapy which may extend and also include surgical management.

Presentation of case

Authors present here two patients with mucormycosis affecting the maxillofacial region, that were treated by including both medical and surgical lines of management.

Discussion

This report aims to highlight the importance of prompt diagnosis and urgent management of this potentially fatal phenomenon, particularly among high-risk individuals.

Conclusion

This case report intensifies the importance of considering mucormycosis as a possible diagnosis in spontaneous necrotic soft tissue lesions of the face, especially in an immunocompromised patient.

Epidemiology and Diagnosis of Mucormycosis: An Update

Mucormycosis is an angioinvasive fungal infection, due to fungi of the order Mucorales. Its incidence cannot be measured exactly, since there are few population-based studies, but multiple studies have shown that it is increasing. The prevalence of mucormycosis in India is about 80 times the prevalence in developed countries, being approximately 0.14 cases per 1000 population. Diabetes mellitus is the main underlying disease globally, especially in low and middle-income countries. In developed countries the most common underlying diseases are hematological malignancies and transplantation. Τhe epidemiology of mucormycosis is evolving as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and as the modern diagnostic tools lead to the identification of previously uncommon genera/species such as Apophysomyces or Saksenaea complex. In addition, new risk factors are reported from Asia, including post-pulmonary tuberculosis and chronic kidney disease. New emerging species include Rhizopus homothallicus, Thamnostylum lucknowense, Mucor irregularis and Saksenaea erythrospora. Diagnosis of mucormycosis remains challenging. Clinical approach to diagnosis has a low sensitivity and specificity, it helps however in raising suspicion and prompting the initiation of laboratory testing. Histopathology, direct examination and culture remain essential tools, although the molecular methods are improving. The internal transcribed spacer (ITS) region is the most widely sequenced DNA region for fungi and it is recommended as a first-line method for species identification of Mucorales. New molecular platforms are being investigated and new fungal genetic targets are being explored. Molecular-based methods have gained acceptance for confirmation of the infection when applied on tissues. Methods on the detection of Mucorales DNA in blood have shown promising results for earlier and rapid diagnosis and could be used as screening tests in high-risk patients, but have to be validated in clinical studies. More, much needed, rapid methods that do not require invasive procedures, such as serology-based point-of-care, or metabolomics-based breath tests, are being developed and hopefully will be evaluated in the near future.

The Diagnostic Pitfalls of Mucormycosis

BACKGROUND

Invasive mucormycosis is a very aggressive fungal disease among immunocompromised pediatric patients caused by saprophytic fungi that belong to the order of the Mucorales.

CASE REPORT

We describe a case of of Lichtheimia corymbifera infection in a 15-year-old child with B-cell-Non-Hodgkin Lymphoma (B-NHL) involving lung, kidney and thyroid that initially was diagnosed as probable aspergillosis delaying the effective therapy for mucormycosis.

CONCLUSIONS

This case showed that also the intensive chemotherapy for B-NHL may represent a risk factor for mucormycosis infection. Liposomal amphotericin B and surgery remain the key tools for the successful treatment of this aggressive disease.

Rare and Fatal Gastrointestinal Mucormycosis (Zygomycosis) in a COVID-19 Patient: A Case Report

The novel coronavirus disease (COVID-19) quickly spread to all continents. However, data regarding all the signs and symptoms of COVID-19 are insufficient. Patients with COVID-19 might present higher susceptibility to fungal coinfections. Mucormycosis is a rare and often life-threatening fungal disease characterized by vascular invasion by hyphae, resulting in thrombosis and necrosis. This is the first case report of mucormycosis in a COVID-19 patient. An 86-year-old male patient was admitted to the emergency room with acute diarrhea, cough, dyspnea, and fever from 5 days prior. Blood tests revealed a hemoglobin level of 14.3 mg/dL. Five days following the admission, the patient presented with melena and a hemoglobin level of 5.6 mg/dL. A transfusion of three units of red blood cells was required. Esophagogastroduodenoscopy revealed two giant gastric ulcers with necrotic debris and a deep hemorrhagic base without active bleeding. Furthermore, biopsies confirmed mucormycosis. Despite intensive care, the patient died 36 hours after the esophagogastroduodenoscopy.

Iron Assimilation during Emerging Infections Caused by Opportunistic Fungi with emphasis on Mucorales and the Development of Antifungal Resistance

Iron is a key transition metal required by most microorganisms and is prominently utilised in the transfer of electrons during metabolic reactions. The acquisition of iron is essential and becomes a crucial pathogenic event for opportunistic fungi. Iron is not readily available in the natural environment as it exists in its insoluble ferric form, i.e., in oxides and hydroxides. During infection, the host iron is bound to proteins such as transferrin, ferritin, and haemoglobin. As such, access to iron is one of the major hurdles that fungal pathogens must overcome in an immunocompromised host. Thus, these opportunistic fungi utilise three major iron acquisition systems to overcome this limiting factor for growth and proliferation. To date, numerous iron acquisition pathways have been fully characterised, with key components of these systems having major roles in virulence. Most recently, proteins involved in these pathways have been linked to the development of antifungal resistance. Here, we provide a detailed review of our current knowledge of iron acquisition in opportunistic fungi, and the role iron may have on the development of resistance to antifungals with emphasis on species of the fungal basal lineage order Mucorales, the causative agents of mucormycosis.

Orbital mucormycosis in immunocompetent children; review of risk factors, diagnosis, and treatment approach

BACKGROUND

Orbital mucormycosis is a rare but potentially severe and troublesome invasive fungal infection that could be occurred even in healthy individuals. The initial clinical presentation is similar to bacterial pre-septal or septal cellulitis, especially in early stages.

CASE PRESENTATION

Herein, we describe the successful management of a series of five cases presenting with orbital mucormycosis in previously healthy children.

CONCLUSIONS

Orbital mucormycosis is extremely rare in healthy children and maybe life-threatening when diagnosis delayed given a similar clinical presentation with bacterial septal cellulitis. Intravenous antifungal therapy with amphotericin B and timely surgical drainage is live-saving.

Interactions of FK506 and Rapamycin With FK506 Binding Protein 12 in Opportunistic Human Fungal Pathogens

Over the past few decades advances in modern medicine have resulted in a global increase in the prevalence of fungal infections. Particularly people undergoing organ transplants or cancer treatments with a compromised immune system are at an elevated risk for lethal fungal infections such as invasive candidiasis, aspergillosis, cryptococcosis, etc. The emergence of drug resistance in fungal pathogens poses a serious threat to mankind and it is critical to identify new targets for the development of antifungals. Calcineurin and TOR proteins are conserved across eukaryotes including pathogenic fungi. Two small molecules FK506 and rapamycin bind to FKBP12 immunophilin and the resulting complexes (FK506-FKBP12 and rapamycin-FKBP12) target calcineurin and TOR, respectively in both humans and fungi. However, due to their immunosuppressive nature these drugs in the current form cannot be used as an antifungal. To overcome this, it is important to identify key differences between human and fungal FKBP12, calcineurin, and TOR proteins which will facilitate the development of new small molecules with higher affinity toward fungal components. The current review highlights FK506/rapamycin-FKBP12 interactions with calcineurin/TOR kinase in human and fungi, and development of non-immunosuppressive analogs of FK506, rapamycin, and novel small molecules in inhibition of fungal calcineurin and TOR kinase.

Invasive fungal disease in humans: are we aware of the real impact?

Despite the medical advances and interventions to improve the quality of life of those in intensive care, people with cancer or severely immunocompromised or other susceptible hosts, invasive fungal diseases (IFD) remain severe and underappreciated causes of illness and death worldwide. Therefore, IFD continue to be a public health threat and a major hindrance to the success of otherwise life-saving treatments and procedures. Globally, hundreds of thousands of people are affected every year with Candida albicans, Aspergillus fumigatus, Cryptococcus neoformans, Pneumocystis jirovecii, endemic dimorphic fungi and Mucormycetes, the most common fungal species causing invasive diseases in humans. These infections result in morbidity and mortality rates that are unacceptable and represent a considerable socioeconomic burden. Raising the general awareness of the significance and impact of IFD in human health, in both the hospital and the community, is hence critical to understand the scale of the problem and to raise interest to help fighting these devastating diseases.

Gastric Mucormycosis: An Infection of Fungal Invasion into the Gastric Mucosa in Immunocompromised Patients

Primary gastric mucormycosis is a rare but potentially lethal fungal infection due to the invasion of Mucorales into the gastric mucosa. It may result in high mortality due to increased risk of complications in immunocompromised patients. Common predisposing risk factors to develop gastric mucormycosis are prolonged uncontrolled diabetes mellitus with or without diabetic ketoacidosis (DKA), solid organ or stem cell transplantation, underlying hematologic malignancy, and major trauma. Abdominal pain, hematemesis, and melena are common presenting symptoms. The diagnosis of gastric mucormycosis can be overlooked due to the rarity of the disease. A high index of suspicion is required for early diagnosis and management of the disease, particularly in immunocompromised patients. Radiological imaging findings are nonspecific to establish the diagnosis, and gastric biopsy is essential for histological confirmation of mucormycosis. Prompt treatment with antifungal therapy is the mainstay of treatment with surgical resection reserved in cases of extensive disease burden or clinical deterioration. We presented a case of acute gastric mucormycosis involving the body of stomach in a patient with poorly controlled diabetes and chronic renal disease, admitted with acute onset of abdominal pain. Complete resolution of lesion was noted with 16 weeks of medical treatment with intravenous amphotericin B and posaconazole.

The Double-Edged Sword of Immunosuppressive Therapy in Kidney Transplantation: A Rare Case Report of Pulmonary Mucormycosis Post-Transplant and Literature Review

Immunosuppressive therapy is improving the graft survival of kidney transplant recipients and increasing the potential risk of infection. Pulmonary mucormycosis is a rare post-operative infection complication characterized with rapid deterioration and high mortality. In this case, a 33-year-old patient underwent a kidney transplantation with regular immunosuppressive therapy. Soon, 38 days post-transplant, pulmonary patchy shadows can be seen in the radiological examination and rounded into a large cavity formation with splenic rupture 25 days later. The diagnosis of mucormycosis was confirmed by lung biopsy and spleen histopathology. This case is a reminder that early diagnosis is imperative, meanwhile, rational antifungal therapy, timely elimination of immunosuppressants, and alternatively, abandoning the graft should be prudently assessed in the treatment of mucormycosis.

Mucormycosis: An 8-year experience of a tertiary care centre in Saudi Arabia

Mucormycosis is a rare fungal infection with an extremely high morbidity and mortality. Data on the burden of the disease in the Arab world is lacking. The aim of this study is to highlight the incidence and outcome of this infection in a tertiary care center in the Kingdom of Saudi Arabia (KSA). In this retrospective study we included all mucormycosis cases admitted to our center between January 2013 and December 2019. A total of 18 proven patients with a median age of 43.5 years (range 13-72 years, 72% males) were identified. The most common presentation was cutaneous and rhino-orbito-cerebral, followed by gastrointestinal mucormycosis. Apophysomyces variabilisRhizopus oryzae) were the main fungal isolates on molecular testing. Trauma was the chief underlying etiology (41.0%) with motor vehicle accident (MVCs) being the predominant type (43.0%). For this reason, most of our patients were young with cutaneous disease and had a better prognosis. All patients received liposomal amphotericin B alone or in combination with other antifungal agents. Repeated aggressive debridement and reversal of the underlying factor was attempted in all patients. This underscores the lower mortality (27.8%) seen in this group. The diagnosis of Mucorales infection is challenging. A high index of suspicion with prompt treatment is required to improve the high mortality of this aggressive disease. Further studies are needed to understand the epidemiology and outcome of this disease in Saudi Arabia.

Mucormycosis in the Middle East and North Africa: Analysis of the FungiScope® registry and cases from the literature

BACKGROUND

Regional differences in the underlying causes, manifestations and treatment of mucormycosis have been noted in studies covering Europe, Asia and South America.

OBJECTIVES

To review cases of mucormycosis across the Middle East and North Africa (MENA) region in order to identify epidemiological, treatment and outcome trends in this region.

PATIENTS/METHODS

Cases of proven or probable invasive mucormycosis from the region were identified from the FungiScope^® database and the medical literature. For each case, information on underlying condition, site of infection, pathogenic species, therapeutic intervention, type of antifungal therapy and outcome were analysed.

RESULTS

We identified 310 cases of mucormycosis in the MENA region. The number of reported cases increased by decade from 23 before 1990 to 127 in the 2010s. In this region, the most common underlying conditions associated with mucormycosis were diabetes mellitus (49.7%) and conditions associated with immunosuppression (46.5%). The majority of patients received treatment with antifungals (93.5%), with a large proportion treated with both antifungals and surgery (70.6%). Overall mortality rates decreased from 47.8% before 1990 to 32.3% in the 2010s.

CONCLUSIONS

The number of reported cases of mucormycosis in the MENA region has risen over the past few decades, in line with increases in the number of patients with underlying conditions associated with this infection. Although the majority of patients received treatment with antifungal therapies and/or surgery, the associated mortality rate remains high and there is a clear need for more effective prevention and treatment strategies in the MENA region.

Rhino-orbital mucormycosis due to Apophysomyces ossiformis in a patient with diabetes mellitus: a case report

Background

The most common aetiological agents of mucormycosis are Rhizopus, Mucor, Apophysomyces and Lichtheimia. Apophysomyces is comparatively rare, as it has been reported in less than 3% of mucormycosis cases. The genus Apophysomyces includes six species, and only A. elegans, A. mexicanus, A. variabilis and A. ossiformis have been reported to cause infections in both immunocompetent and immunocompromised patients.

Case presentation

We present a case of a 46-year-old male patient with bilateral blepharoedema, corneal opacity in the left eye and poorly controlled diabetes mellitus. The patient was subjected to total maxillectomy, exenteration of the left orbit and treatment with liposomal amphotericin B. Direct mycological analysis with KOH 10% revealed hyaline, coenocytic, long and wide hyphae. Apophysomyces ossiformis was identified from maxillary biopsy using 18S-ITS1–5.8S-ITS2-28S rRNA gene amplification and sequencing. The patient requested to be transferred to another hospital to continue treatment, where he died on the ninth day after admittance.

Conclusion

To the best of our knowledge, this is the first case of rhino-orbital mucormycosis due to A. ossiformis with a fatal outcome. This case reveals the need to identify the fungus causing mucormycosis with molecular methods to identify adequate treatment therapies for patients with this infection.

In vitro interactions between isavuconazole and tacrolimus, cyclosporin A or sirolimus against Mucorales

OBJECTIVES

To evaluate the in vitro interactions of isavuconazole with immune suppressors (tacrolimus, cyclosporin A or sirolimus) against 30 Mucorales isolates belonging to the most common species responsible for mucormycosis in humans (Rhizopus arrhizus, Rhizopus delemar, Rhizopus microsporus, Lichtheimia corymbifera, Lichtheimia ramosa, Mucor circinelloides and Rhizomucor pusillus).

METHODS

In vitro interaction was evaluated by a microdilution chequerboard technique.

RESULTS

Combination of isavuconazole with tacrolimus, cyclosporin A or sirolimus, was synergistic for 50%, 46% and 7% of the isolates, respectively. Antagonistic interaction was observed for 4% of the isolates for the combination with cyclosporin A (one R. arrhizus isolate) and for 32% of the isolates for the combination with sirolimus (six R. arrhizus isolates and three R. pusillus isolates).

CONCLUSIONS

These in vitro data show that calcineurin inhibitors are more likely than inhibitors of the mTOR pathway to enhance the activity of isavuconazole against Mucorales. These in vitro results warrant further animal experiments.

Mucormycosis of Neck a Rare Presentation

Mucormycosis is a dreaded clinical entity caused by filamentous fungi of the order Mucorales mainly affecting immunocompromised individuals. Usually seen involving paranasal sinuses, orbit, lungs and gastrointestinal system, it is extremely rare in other areas. Herein we report a rare presentation of Mucormycosis affecting the ear and neck where early detection, timely intervention, multidisciplinary involvement and judicious use of local antibiotics apart from the mainstay treatment regimen like surgical debridement and intravenous Amphotericin B has saved the patient and given him a reasonably good quality of life devoid of morbidity.

Pulmonary mucormycosis following autologous hematopoietic stem cell transplantation for rapidly progressive diffuse cutaneous systemic sclerosis: A case report

RATIONALE

The use of autologous hematopoietic stem cell transplantation (AHSCT) for autoimmune diseases has become the first indication for transplant in nonmalignant disease. Mucormycosis is a rare invasive infection with increasing incidence in patients treated with AHSCT. We report the first case of pulmonary mucormycosis following AHSCT for systemic sclerosis (SSc).

PATIENT CONCERNS

A 24-year-old woman with rapidly progressive diffuse cutaneous SSc presented with an acute respiratory distress syndrome 6 days after AHSCT.

DIAGNOSES

The results of clinical and computed tomography scan were consistent with pulmonary mucormycosis and the diagnosis was confirmed by a positive Mucorales Polymerase Chain Reaction on a peripheral blood sample.

INTERVENTIONS AND OUTCOMES

Early antifungal therapy by intravenous amphotericin B provided rapid improvement within 4 days and sustained recovery after 2 years of follow-up.

LESSONS

With the progressively increasing use of AHSCT and other stem cell therapy for treatment of severe SSc and other autoimmune diseases, the potential onset of rare post-transplant fungal infections, such as mucormycosis, requires careful patient monitoring and better awareness of early initiation of adequate therapy.

Development and validation of the European QUALity (EQUAL) score for mucormycosis management in haematology

BACKGROUND

Mucormycosis is a life-threatening infection in immunocompromised patients and in haematological malignancy patients in particular.

OBJECTIVES

Our aim was to develop and evaluate a scoring tool to measure adherence to current guidelines for mucormycosis.

METHODS

Current guidelines of scientific societies on mucormycosis management were reviewed. We assembled diagnostic, treatment and follow-up milestones and designed the EQUAL Mucormycosis Score. The EQUAL Mucormycosis Score was evaluated in the ECMM Excellence Centres.

RESULTS

An 18-item tool with one to three points per item resulted in a maximum achievable score depending on disease complexity and ranging from 25 to 32 points. Given variable patient disease course, the diagnostic score is higher in patients with positive fungal culture and biopsy, thus reflecting more decision points and higher management complexity. Eleven patients from two centres were included during the study period. A total of 200 EQUAL Mucormycosis Score points were achieved, which is 62.7% of the maximum EQUAL Mucormycosis Score of 319 points achievable in that cohort (median 18 points, range 7-27). The total score accomplished for diagnostic procedures was 112 of 165 points (67.9%), for first-line treatment 54 of 88 (61.4%) and for follow-up management 34 of 66 points (51.5%).

CONCLUSIONS

The EQUAL Mucormycosis Score quantitates adherence to current guideline recommendations for mucormycosis management. With 62.7% of maximum achievable score points, a first result is obtained that may serve as a reference for future evaluations. It remains to be shown whether guideline adherence and mortality rates correlate.

Advances in the diagnosis of fungal pneumonias

INTRODUCTION

Fungal infections are increasingly encountered in clinical practice due to more favorable environmental conditions and increasing prevalence of immunocompromised individuals. The diagnostic approach for many fungal pathogens continues to evolve. Herein, we outline available diagnostic tests for the most common fungal infections with a focus on recent advances and future directions.

AREAS COVERED

We discuss the diagnostic testing methods for angioinvasive molds (Aspergillus spp. and Mucor spp.), invasive yeast (Candida spp. and Cryptococcus ssp.), Pneumocystis, and endemic fungi (Blastomyces sp., Coccidioides ssp., and Histoplasma sp.). The PubMed-NCBI database was searched within the past 5 years to identify the most recent available literature with dates extended in cases where literature was sparse. Diagnostic guidelines were utilized when available with references reviewed.

EXPERT OPINION

Historically, culture and/or direct visualization of fungal organisms were required for diagnosis of infection. Significant limitations included ability to collect specimens and delayed diagnosis associated with waiting for culture results. Antigen and antibody testing have made great strides in allowing quicker diagnosis of fungal infections but can be limited by low sensitivity/specificity, cross-reactivity with other fungi, and test availability. Molecular methods have a rich history in some fungal diseases, while others continue to be developed.

A non-canonical RNAi pathway controls virulence and genome stability in Mucorales

Epimutations in fungal pathogens are emerging as novel phenomena that could explain the fast-developing resistance to antifungal drugs and other stresses. These epimutations are generated by RNA interference (RNAi) mechanisms that transiently silence specific genes to overcome stressful stimuli. The early-diverging fungus Mucor circinelloides exercises a fine control over two interacting RNAi pathways to produce epimutants: the canonical RNAi pathway and a new RNAi degradative pathway. The latter is considered a non-canonical RNAi pathway (NCRIP) because it relies on RNA-dependent RNA polymerases (RdRPs) and a novel ribonuclease III-like named R3B2 to degrade target transcripts. Here in this work, we uncovered the role of NCRIP in regulating virulence processes and transposon movements through key components of the pathway, RdRP1 and R3B2. Mutants in these genes are unable to launch a proper virulence response to macrophage phagocytosis, resulting in a decreased virulence potential. The transcriptomic profile of rdrp1Δ and r3b2Δ mutants revealed a pre-exposure adaptation to the stressful phagosomal environment even when the strains are not confronted by macrophages. These results suggest that NCRIP represses key targets during regular growth and releases its control when a stressful environment challenges the fungus. NCRIP interacts with the RNAi canonical core to protect genome stability by controlling the expression of centromeric retrotransposable elements. In the absence of NCRIP, these retrotransposons are robustly repressed by the canonical RNAi machinery; thus, supporting the antagonistic role of NCRIP in containing the epimutational pathway. Both interacting RNAi pathways might be essential to govern host-pathogen interactions through transient adaptations, contributing to the unique traits of the emerging infection mucormycosis.

Understanding Mucormycoses in the Age of "omics"

Mucormycoses are deadly invasive infections caused by several fungal species belonging to the subphylum Mucoromycotina, order Mucorales. Hallmarks of disease progression include angioinvasion and tissue necrosis that aid in fungal dissemination through the blood stream, causing deeper infections and resulting in poor penetration of antifungal agents to the site of infection. In the absence of surgical removal of the infected focus, antifungal therapy alone is rarely curative. Even when surgical debridement is combined with high-dose antifungal therapy, the mortality associated with mucormycoses is >50%. The unacceptably high mortality rate, limited options for therapy and the extreme morbidity of highly disfiguring surgical therapy provide a clear mandate to understand the molecular mechanisms that govern pathogenesis with the hopes of developing alternative strategies to treat and prevent mucormycoses. In the absence of robust forward and reverse genetic systems available for this taxonomic group of fungi, unbiased next generation sequence (NGS)-based approaches have provided much needed insights into our understanding of many aspects of Mucormycoses, including genome structure, drug resistance, diagnostic development, and fungus-host interactions. Here, we will discuss the specific contributions that NGS-based approaches have made to the field and discuss open questions that can be addressed using similar approaches.

Tornadic Shear Stress Induces a Transient, Calcineurin-Dependent Hypervirulent Phenotype in Mucorales Molds

Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.IMPORTANCE Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.

Occurrence and species diversity of human-pathogenic Mucorales in commercial food-stuffs purchased in Paris area

Mucormycoses are life-threatening fungal diseases that affect a variety of patients including those with diabetes mellitus or hematological malignancies. The responsible agents, the Mucorales, are opportunistic pathogens originating from the environment such as soil or decaying organic matter. The aim of the present study was to assess the prevalence and diversity of human-pathogenic species of Mucorales in commercially available foodstuffs in France. All food samples were purchased from January 2014 to May 2015 in France. A total of 159 dried food samples including spices and herbs (n = 68), herbal tea (n = 19), cereals (n = 19), vegetables (n = 14), and other foodstuffs (n = 39) were analyzed. Each strain of Mucorales was identified phenotypically, and molecular identification was performed by ITS sequencing. From the 28 (17.6%) samples that were culture-positive for Mucorales, 30 isolates were recovered. Among the isolates, 13 were identified as Rhizopus arrhizus var. arrhizus, 10 R. arrhizus var. delemar, two Rhizopus microsporus, one Lichtheimia corymbifera, three Lichtheimia ramosa, and one Syncephalastrum racemosum. Culture-positive samples originated from different countries (Europe, Asia) and brands. The samples most frequently contaminated by Mucorales were spices and herbs (19/68, 27.9%), followed by herbal tea (2/19, 10.5%), cereals (2/19, 10.5%), other food products (5/39, 12.8%). The present study showed that human-pathogenic Mucorales were frequently recovered from commercially available foodstuffs in France with a large diversity of species. The potential danger represented by Mucorales present in food for immunocompromised patients should be further analyzed.

CRISPR-Cas9-Based Mutagenesis of the Mucormycosis-Causing Fungus Lichtheimia corymbifera

Lichtheimia corymbifera is considered as one of the most frequent agents of mucormycosis. The lack of efficient genetic manipulation tools hampers the characterization of the pathomechanisms and virulence factors of this opportunistic pathogenic fungus. Although such techniques have been described for certain species, the performance of targeted mutagenesis and the construction of stable transformants have remained a great challenge in Mucorales fungi. In the present study, a plasmid-free CRISPR-Cas9 system was applied to carry out a targeted gene disruption in L. corymbifera. The described method is based on the non-homologous end-joining repair of the double-strand break caused by the Cas9 enzyme. Using this method, short, one-to-five nucleotide long-targeted deletions could be induced in the orotidine 5′-phosphate decarboxylase gene (pyrG) and, as a result, uracil auxotrophic strains were constructed. These strains are applicable as recipient strains in future gene manipulation studies. As we know, this is the first genetic modification of this clinically relevant fungus.

Risk factors for mortality in patients with pulmonary mucormycosis

BACKGROUND

Pulmonary mucormycosis (PM) represents a serious burden in terms of morbidity and mortality in immunocompromised patients. Studies of prognostic factors in patients with PM are limited and have involved small numbers of patients.

METHODS

Adult patients diagnosed with proven and probable PM according to the modified definitions of the EORTC/MSG 2008 in a tertiary hospital in Seoul, South Korea, between 2008 and 2019 were retrospectively enrolled.

RESULTS

A total of 49 patients including 31 (63%) with proven PM and 18 (37%) with probable PM were enrolled. The 90-day mortality rate was 49% (24/49). Neutropenia, thrombocytopenia, use of voriconazole at clinical suspicion, positivity of non-sterile culture, use of steroid and treatment without surgery were more common in fatal cases than non-fatal cases. Voriconazole use at clinical suspicion for invasive mould pneumonia (OR 6.91, P = .01) and prolonged neutropenia (OR 4.86, P = .03) were independent risk factors for mortality. Voriconazole use at clinical suspicion was associated with positive galactomannan (GM) assay (OR 5.93, P = .02) and history of invasive pulmonary aspergillosis (OR, 6.88, P = .05).

CONCLUSION

About half of the patients with PM died within 90 days of diagnosis, and fatal outcomes were common in patients with prolonged neutropenia and empirical voriconazole use. Caution is needed in using voriconazole even in patients with positive GM results and prior histories of invasive pulmonary aspergillosis in whom PM cannot be ruled out by differential diagnosis.

Multicopper Oxidases in Saccharomyces cerevisiae and Human Pathogenic Fungi

Multicopper oxidases (MCOs) are produced by microscopic and macroscopic fungal species and are involved in various physiological processes such as morphogenesis, lignin degradation, and defense mechanisms to stress inducing environmental conditions as well as fungal virulence. This review will summarize our current understanding regarding the functions of MCOs present in Saccharomyces cerevisiae and in different human fungal pathogens. Of the two main MCO groups, the first group of MCOs is involved in iron homoeostasis and the second includes laccases. This review will also discuss their role in the pathogenesis of human fungal pathogens.

Current burden of serious fungal infections in Republic of Congo

BACKGROUND

The Republic of Congo (RoC) is characterised by a high prevalence of tuberculosis and HIV/AIDS, which largely drive the epidemiology of serious fungal infections.

OBJECTIVE

We aimed to estimate the current burden of serious fungal infections in RoC.

MATERIAL AND METHODS

Using local, regional or global data and estimates of population and at-risk population groups, deterministic modelling was employed to estimate national incidence or prevalence of the most serious fungal infections.

RESULTS

Our study revealed that about 5.4% of the Congolese population (283 450) suffer from serious fungal infections yearly. The incidence of cryptococcal meningitis, Pneumocystis jirovecii pneumonia and disseminated histoplasmosis in AIDS patients was estimated at 560, 830 and 120 cases per year. Oral and oesophageal candidiasis collectively affects 12 320 HIV-infected patients. Chronic pulmonary aspergillosis, 67% post-tuberculosis, probably has a prevalence of 3420. Fungal asthma (allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitisation) probably has a prevalence of 3640 and 4800, although some overlap due to disease definition is likely. The estimated prevalence of recurrent vulvovaginal candidiasis and tinea capitis is 85 440 and 178 400 respectively. Mostly related to agricultural activity, fungal keratitis affects an estimated 700 Congolese yearly.

CONCLUSION

These data underline the urgent need for an intensified awareness towards Congolese physicians to fungal infections and for increased efforts to improve diagnosis and management of fungal infections in the RoC.

Case of mucormycosis of mandible after self-extraction of teeth incidentally detected to have chronic granulomatous disease: Case report and literature review

Mucormycosis isolated to the mandible is a rare presentation occurring generally after dental procedures. The case we report presented with discharging sinuses over facial region with radiological appearance of isolated osteomyelitis of the mandible. The patient used to apply an addictive dental powder over his teeth leading to caries. Following this, he pulled out all his teeth, which probably led to his condition. Invasive sampling revealed mucormycosis. An extensive search for an underlying immunodeficiency revealed that the patient had chronic granulomatous disease (CGD). Despite a prolonged course of L-Amphotericin B, the patient continued to have intermittent pus discharge and surgical debridement and curettage was eventually required. The patient had a chronic course with minimal soft tissue involvement which initially did not raise the suspicion of mucormycosis. The main learning point is that an unusual invasive fungal infection in an otherwise healthy host can be the first symptom of an underlying primary immunodeficiency, like CGD. Invasive fungal infections in patients with CGD often have an indolent course.

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Mucormycosis isolated to the mandible is a rare presentation, occurring generally after dental procedures.

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Self-extraction of teeth as in our patient can result in isolated mucormycosis of the mandible.

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Isolated mucormycosis of the mandible can be a presenting symptom of chronic granulomatous disease.

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Combination of medical and surgical treatment is usually needed in mandibular mucormycosis.

Traumatic Mucormycosis of Auricular Cartilage in an Iranian Diabetic Patient

Mucormycosis is an uncommon and acute fungal infection, with high morbidity and mortality. Traumatic mucormycosis mainly occurs in military conflicts, civilian trauma, and vehicle accidents. Hurricanes, tornadoes, floods, and tsunamis also play a major role in causing mucormycosis by inoculation. Herein, we presented a case of trauma-related mucormycosis in a 70-year-old diabetic male. He referred to a specialty clinic due to the auricular swelling after having fallen and having a major trauma in his ear. Pathologic examination of necrotic cartilage revealed broad ribbon like aseptate hyphae. Antifungal therapy with amphotericin B deoxycholate (1.5 mg/kg/day) was administered for 6 weeks as an initial therapy, and the patient was discharged with a regimen of posaconazole oral solution (400 mg PO bid with meals) for 8 weeks. He followed up for one year and there was no recurrence of the infection. In conclusion, traumatic mucormycosis is a rare but potentially life-threatening fungal infection. Early diagnosis and surgical excision are essential regarding the management of this critical condition. Knowing the underlying diseases is preferable to early diagnosis and timely initiation of antifungal therapy in order to improve survival rates.

Rapid and Low-Cost Culture-Based Method for Diagnosis of Mucormycosis Using a Mouse Model

Prompt and targeted antifungal treatment has a positive impact on the clinical outcome of mucormycosis; however, current diagnostic tools used in histopathology laboratories often fail to provide rapid results. Rapid culture-based strategies for early diagnosis of Mucorales infections, which may influence treatment decisions, are urgently needed. Herein, we evaluated a microculture assay for the early diagnosis of mucormycosis in an immunocompetent murine model of disseminated infection, by comparing it with traditional diagnostic methods. The assay specificity was assessed using blood (n = 90) and tissue (n = 90) specimens obtained from mice infected with Rhizopus arrhizus using different inoculum sizes [1 × 10⁴, 1 × 10⁵, and 1 × 10⁶ colony forming units (CFUs)/mouse] and blood (n = 15) and tissue specimens (n = 15) from uninfected mice. Surprisingly, 26 of 90 (28.9%) blood samples revealed positive results by microculture, whereas all blood samples were negative when assayed by conventional culture. The overall positive conventional culture rate for the mouse tissue (kidney) samples was 31.1% (28/90). The calculated sensitivity for kidney microculture was 98.8% [95% confidence interval (CI) 96.6–100], with an assay specificity of 100%. Hence, the microculture assay may be useful for rapid culturing and diagnosis of mucormycosis caused by R. arrhizus directly in blood and tissue samples. Hence, this method may allow for the timely administration of an appropriate treatment.

Genes, Pathways, and Mechanisms Involved in the Virulence of Mucorales

The order Mucorales is a group of ancient fungi with limited tools for gene manipulation. The main consequence of this manipulation unwillingness is the limited knowledge about its biology compared to other fungal groups. However, the emerging of mucormycosis, a fungal infection caused by Mucorales, is attracting the medical spotlight in recent years because the treatments available are not efficient in reducing the high mortality associated with this disease. The result of this renewed interest in Mucorales and mucormycosis is an extraordinarily productive effort to unveil their secrets during the last decade. In this review, we describe the most compelling advances related to the genetic study of virulence factors, pathways, and molecular mechanisms developed in these years. The use of a few genetic study models has allowed the characterization of virulence factors in Mucorales that were previously described in other pathogens, such as the uptake iron systems, the mechanisms of dimorphism, and azole resistances. More importantly, recent studies are identifying new genes and mechanisms controlling the pathogenic potential of Mucorales and their interactions with the host, offering new alternatives to develop specific strategies against mucormycosis.

Invasive intestinal mucormycosis in a 40-year old immunocompetent patient - a rarely reported clinical phenomenon: a case report

BACKGROUND

Mucormycosis is rare, life-threatening fungal infection. Frequently observed in those patients having underlying immunosuppression such as, diabetes, organ transplantation, Human immunodeficiency virus (HIV) infection, and elevated serum iron. However, invasive intestinal mucormycosis occurring in immunocompetent individuals without the traditional risk factors is extremely rare clinical phenomenon.

CASE PRESENTATION

We report a 40-year-old male patient who presented with 1 week history of diffuse abdominal pain and high grade fever, associated with vomiting and frequent loose stools. Has history of chronic alcohol ingestion. Otherwise, no past history of chronic medical illness, nor he had contact with individuals with similar illness. He was in a septic shock with multiple organ failure up on presentation to emergency room. Physical examination revealed icterus sclera with abdominal tenderness. He was immediately resuscitated using crystalloids, supported with inotrope, and antibiotics. Histopathological examination of tissue sample from colonic ulcer biopsy revealed invasive intestinal mucormycosis. Patient showed full clinical and histopathological resolution after course of parenteral Liposomal Amphotercin B.

CONCLUSION

This case highlights the fact that, despite its life-threatening nature, it's possible to treat patients with invasive intestinal mucormycosis with aggressive antifungal and supportive care without surgical intervention, provided that all the necessary supportive care were initiated early and the disease was diagnosed early and appropriate medical management was initiated timely. In addition, it's important to consider intestinal mucormycosis even in patients who are immunocompetent without traditional risk factors.

Metagenomic Next-Generation Sequencing versus Traditional Pathogen Detection in the Diagnosis of Peripheral Pulmonary Infectious Lesions

Purpose

The aim of this study was to evaluate the value of metagenomic next-generation sequencing (mNGS) in peripheral pulmonary infection management by comparing the diagnostic yield of mNGS and traditional pathogen detection methods on interventional specimens obtained by bronchoscopy.

Patients and Methods

This study enrolled patients suspected with pulmonary infection who were admitted to Tianjin Medical University General Hospital from June 2018 to August 2019. Specimens were obtained from bronchoscopy for mNGS analysis and traditional pathogen detection (including bronchoalveolar lavage fluid microbial culture, smear microscopy, and lung biopsy histopathology), and the diagnostic yields were compared between mNGS and traditional methods to evaluate the diagnostic value of mNGS in peripheral pulmonary infection diagnosis.

Results

In this study, by comparing mNGS with traditional pathogen detection, the results indicated that, first, mNGS identified at least one microbial species in almost 89% of the patients with pulmonary infection; second, mNGS detected microbes related to human diseases in 94.49% of samples from pulmonary infection patients who had received negative results from traditional pathogen detection; third, the accuracy and sensitivity of mNGS are higher than those of traditional pathogen detection; and, finally, mNGS could simultaneously detect and identify a large variety of pathogens.

Conclusion

Metagenomic NGS analysis provided fast and precise pathogen detection and identification, contributing to prompt and accurate treatment of peripheral pulmonary infection.

Comparative genomics applied to Mucor species with different lifestyles

BACKGROUND

Despite a growing number of investigations on early diverging fungi, the corresponding lineages have not been as extensively characterized as Ascomycota or Basidiomycota ones. The Mucor genus, pertaining to one of these lineages is not an exception. To this date, a restricted number of Mucor annotated genomes is publicly available and mainly correspond to the reference species, Mucor circinelloides, and to medically relevant species. However, the Mucor genus is composed of a large number of ubiquitous species as well as few species that have been reported to specifically occur in certain habitats. The present study aimed to expand the range of Mucor genomes available and identify potential genomic imprints of adaptation to different environments and lifestyles in the Mucor genus.

RESULTS

In this study, we report four newly sequenced genomes of Mucor isolates collected from non-clinical environments pertaining to species with contrasted lifestyles, namely Mucor fuscus and Mucor lanceolatus, two species used in cheese production (during ripening), Mucor racemosus, a recurrent cheese spoiler sometimes described as an opportunistic animal and human pathogen, and Mucor endophyticus, a plant endophyte. Comparison of these new genomes with those previously available for six Mucor and two Rhizopus (formerly identified as M. racemosus) isolates allowed global structural and functional description such as their TE content, core and species-specific genes and specialized genes. We proposed gene candidates involved in iron metabolism; some of these genes being known to be involved in pathogenicity; and described patterns such as a reduced number of CAZymes in the species used for cheese ripening as well as in the endophytic isolate that might be related to adaptation to different environments and lifestyles within the Mucor genus.

CONCLUSIONS

This study extended the descriptive data set for Mucor genomes, pointed out the complexity of obtaining a robust phylogeny even with multiple genes families and allowed identifying contrasting potentially lifestyle-associated gene repertoires. The obtained data will allow investigating further the link between genetic and its biological data, especially in terms of adaptation to a given habitat.

Primary cutaneous mucormycosis of the abdomen at the site of repeated insulin injections

A 71-year-old woman with metastatic squamous cell carcinoma of the lung and insulin-dependent type 2 diabetes mellitus presented with a necrotic lesion on her lower abdomen. Further history revealed that this was the site of repeat insulin injections with reuse of the same needles. On investigation, biopsy of the site was positive for broad, aseptate, right-angle branching fungal hyphae consistent with mucormycosis. Studies have shown that insulin needle reuse is a common practice among diabetics for several reasons, including cost and convenience. While the current American Diabetes Association guidelines suggest that this is an acceptable practice among the general population of diabetics, they advise against it in patients who are actively ill or immunocompromised. Discussion about insulin needle reuse should be of utmost importance among providers and their diabetic patients, especially for patients who are immunocompromised.

Superficial Cutaneous Zygomycosis Presenting as Resistant Intertrigo: A Case Report

Zygomycosis is an angioinvasive fungal infection with a high mortality rate. Cutaneous zygomycosis is the second most common form of the disease, typically characterized by necrotic eschars in an immunocompromised host. We report an unusual case of superficial intertrigo resistant to conventional therapies caused by Mucor circinelloides in a patient with HIV and diabetes.

A Rare Case of Fatal Endobronchial Mucormycosis Masquerading as Endobronchial Tuberculosis

Pulmonary mucormycosis is a relatively rare but often fatal opportunistic fungal infection that occurs mostly in immunocompromised patients. Endobronchial mucormycosis, a distinct clinical form of pulmonary mucormycosis, is very rare, and only a few cases have been reported. The most common bronchoscopic findings in patients with endobronchial mucormycosis are stenosis, erythematous mucosa and airway obstruction. Here, we present a case of fatal endobronchial mucormycosis mimicking actively caseating endobronchial tuberculosis in a young diabetic patient living in a country with an intermediate tuberculosis burden.

A Novel Resistance Pathway for Calcineurin Inhibitors in the Human-Pathogenic Mucorales Mucor circinelloides

Mucormycosis is an emerging lethal fungal infection in immunocompromised patients. Mucor circinelloides is a causal agent of mucormycosis and serves as a model system to understand genetics in Mucorales. Calcineurin is a conserved virulence factor in many pathogenic fungi, and calcineurin inhibition or deletion of the calcineurin regulatory subunit (CnbR) in Mucor results in a shift from hyphal to yeast growth. We analyzed 36 calcineurin inhibitor-resistant or bypass mutants that exhibited hyphal growth in the presence of calcineurin inhibitors or in the yeast-locked cnbRΔ mutant background without carrying any mutations in known calcineurin components. We found that a majority of the mutants had altered sequence in a gene, named here bycA (bypass of calcineurin). bycA encodes an amino acid permease. We verified that both the bycAΔ single mutant and the bycAΔ cnbRΔ double mutant are resistant to calcineurin inhibitor FK506, thereby demonstrating a novel mechanism of resistance against calcineurin inhibitors. We also found that the level of expression of bycA was significantly higher in the wild-type strain treated with FK506 and in the cnbRΔ mutants but was significantly lower in the wild-type strain without FK506 treatment. These findings suggest that bycA is a negative regulator of hyphal growth and/or a positive regulator of yeast growth in Mucor and that calcineurin suppresses expression of the bycA gene at the mRNA level to promote hyphal growth. BycA is involved in the Mucor hypha-yeast transition as our data demonstrate positive correlations among bycA expression, protein kinase A activity, and Mucor yeast growth. Also, calcineurin, independently of its role in morphogenesis, contributes to virulence traits, including phagosome maturation blockade, host cell damages, and proangiogenic growth factor induction during interactions with hosts.IMPORTANCEMucor is intrinsically resistant to most known antifungals, which makes mucormycosis treatment challenging. Calcineurin is a serine/threonine phosphatase that is widely conserved across eukaryotes. When calcineurin function is inhibited in Mucor, growth shifts to a less virulent yeast growth form, which makes calcineurin an attractive target for development of new antifungal drugs. Previously, we identified two distinct mechanisms through which Mucor can become resistant to calcineurin inhibitors involving Mendelian mutations in the gene for FKBP12, including mechanisms corresponding to calcineurin A or B subunits and epimutations silencing the FKBP12 gene. Here, we identified a third novel mechanism where loss-of-function mutations in the amino acid permease corresponding to the bycA gene contribute to resistance against calcineurin inhibitors. When calcineurin activity is absent, BycA can activate protein kinase A (PKA) to promote yeast growth via a cAMP-independent pathway. Our data also show that calcineurin activity contributes to host-pathogen interactions primarily in the pathogenesis of Mucor.

Microsatellite analysis of the population structure in Rhizopus arrhizus

OBJECTIVES

Rhizopus arrhizus is recognized as an emergent agent of superficial and invasive mucormycosis. Despite an increasing number of these infections, the molecular epidemiology of Rhizopus species has not been well studied.

MATERIALS AND METHODS

In this study, 43 R. arrhizus strains (25 environmental and 18 clinical isolates) were genotyped using six novel panels of microsatellite markers.

RESULTS

Upon the analysis of 43 isolates, 4-8 distinct alleles were detected for each marker. The discriminatory power for the individual markers ranged from 0·522 to 0·830. The combination of all six markers yielded 33 different haplotypes with a high degree of discrimination (0·989 D value). A four-marker combination were selected as the most parsimonious panel achieving D > 0·95. One clinical isolate and one environmental isolate shared the same genotype suggesting the possible nosocomial outbreak of mucormycosis in hospitalized patients. We have noted that the strains isolated from cutaneous mucormycosis were different from the strains isolated from rhino-orbito-cerebral mucormycosis. Then, the hypothesis of particular tropism of infectious strains for a given site is not excluded. The standardized indices of association IA and rBarD were significantly different from zero (P < 0·01), suggesting a prevailing clonal reproduction. The environmental population was significantly differentiated from clinical populations (Fst = 0·2249).

CONCLUSIONS

Microsatellite typing method described in our study showed an excellent degree of discriminatory power. It is a promising tool for illuminating the molecular epidemiology of R. arrhizus species, including strain relatedness and transmission pathways.

Alteration of Fermentative Metabolism Enhances Mucor circinelloides Virulence

The fungus Mucor circinelloides undergoes yeast-mold dimorphism, a developmental process associated with its capability as a human opportunistic pathogen. Dimorphism is strongly influenced by carbon metabolism, and hence the type of metabolism likely affects fungus virulence. We investigated the role of ethanol metabolism in M. circinelloides virulence. A mutant in the adh1 gene (M5 strain) exhibited higher virulence than the wild-type (R7B) and the complemented (M5/pEUKA-adh1 ⁺) strains, which were nonvirulent when tested in a mouse infection model. Cell-free culture supernatant (SS) from the M5 mutant showed increased toxic effect on nematodes compared to that from R7B and M5/pEUKA-adh1 ⁺ strains. The concentration of acetaldehyde excreted by strain M5 in the SS was higher than that from R7B, which correlated with the acute toxic effect on nematodes. Remarkably, strain M5 showed higher resistance to H₂O₂, resistance to phagocytosis, and invasiveness in mouse tissues and induced an enhanced systemic inflammatory response compared with R7B. The mice infected with strain M5 under disulfiram treatment exhibited only half the life expectancy of those infected with M5 alone, suggesting that acetaldehyde produced by M. circinelloides contributes to the toxic effect in mice. These results demonstrate that the failure in fermentative metabolism, in the step of the production of ethanol in M. circinelloides, contributes to its virulence, inducing a more severe tissue burden and inflammatory response in mice as a consequence of acetaldehyde overproduction.

Quantifying guideline adherence in mucormycosis management using the EQUAL score

OBJECTIVES

Mucormycosis is a difficult-to-diagnose life-threatening disease with high morbidity and mortality. Adherence to guidelines that lead through complex management and support clinical decisions is however rarely reported. By applying the EQUAL Score, our study evaluates the management of mucormycosis at the University Hospital of Cologne, Germany.

METHODS

We performed a retrospective chart review of patients with mucormycosis at the University Hospital of Cologne. Data collection comprised items for quality assessment in mucormycosis management according to the EQUAL Mucormycosis Score and economics.

RESULTS

Of 29 patients identified, 27 were documented retrospectively. Eight patients of 18 with neutropenia (>10 days) or receiving allogeneic stem cell transplantation (44.4%) received mould active prophylaxis. Chest CT was done in 21 patients (77.8%), while BAL and direct microscopy of BAL fluid was performed in 22 patients (81.5%), culture in 22 (81.5%) and fungal PCR in 24 (88.9%). First-line treatment was liposomal amphotericin B in 19 patients (70.4%). Isavuconazole or posaconazole with therapeutic drug monitoring was used in four (14.8%) and in one patient (3.7%), respectively. In our cohort, crude mortality was 51.9% (n = 14) with a median survival time of 113 days. During the management of the 27 patients, 450 points (53.8%) of the maximum EQUAL Mucormycosis Score were achieved (median 15 points, range 6-30).

CONCLUSIONS

We observed management of mucormycosis aligning with current guidelines and hope to encourage other groups to use the EQUAL Score in routine clinical settings. Future studies will evaluate whether guideline adherence in mucormycosis management improves patient outcome.