Disseminated mucormycosis caused by Absidia corymbifera leading to cerebral vasculitis

Imaging spectrum in rhino-orbito-cerebral mucormycosis: a cross-sectional study

Background

Rhino-orbital-cerebral mucormycosis (ROCM) is a life-threatening condition caused by a saprophytic fungus that predominately affecting immune-compromised patients. Early diagnosis of ROCM is of utmost importance to start the treatment as early as possible to prevent early and horrible complications of the disease.

Materials and methods

This retrospective study evaluated the imaging findings of 21 patients with biopsy and KOH mount-based evidence of invasive ROCM. The imaging was obtained from a Siemens Magnetom Amira 1.5T system with a strength of 1.5T or more. The spectrum of findings was evaluated for the sites of involvement, signal intensity, contrast characteristics, necrotic component as well as orbital, infratemporal, and intracranial extensions, especially cavernous sinuses, Meckel's cave, and the brain parenchyma.

Results

The mean age of the patients was 55.8±10.9 years and included 71% male. All the patients were positive for COVID-19 and the majority were diabetic. MRI showed predominant involvement of the maxillary sinus (17, 81%) and the ethmoidal sinus (15, 71.4%). The orbital extension was present in 18 cases (86%). T1-weighted imaging showed iso to low signal intensity in involved sinuses in the majority of the patients (9, 42.9%). Heterogeneously high signal intensity was observed in T2-weighted and short tau inversion recovery images in all the patients. Heterogenous contrast enhancement was present in 20 (95.2%) patients.

Conclusion

The imaging spectrum of ROCM is variable. Multiplanar MRI with postcontrast images is a very useful complementary tool to the clinical evaluation to assess the extent of disease and its complications, which has a high mortality. Clinicians and radiologists should be aware of the imaging spectrums of ROCM.

The TLR-NF-kB axis contributes to the monocytic inflammatory response against a virulent strain of Lichtheimia corymbifera, a causative agent of invasive mucormycosis

Invasive mucormycosis (IM) is a life-threatening infection caused by the fungal order Mucorales, its diagnosis is often delayed, and mortality rates range from 40-80% due to its rapid progression. Individuals suffering from hematological malignancies, diabetes mellitus, organ transplantations, and most recently COVID-19 are particularly susceptible to infection by Mucorales. Given the increase in the occurrence of these diseases, mucormycosis has emerged as one of the most common fungal infections in the last years. However, little is known about the host immune response to Mucorales. Therefore, we characterized the interaction among L. corymbifera—one of the most common causative agents of IM—and human monocytes, which are specialized phagocytes that play an instrumental role in the modulation of the inflammatory response against several pathogenic fungi. This study covered four relevant aspects of the host-pathogen interaction: i) The recognition of L. corymbifera by human monocytes. ii) The intracellular fate of L. corymbifera. iii) The inflammatory response by human monocytes against the most common causative agents of mucormycosis. iv) The main activated Pattern-Recognition Receptors (PRRs) inflammatory signaling cascades in response to L. corymbifera. Here, we demonstrate that L. corymbifera exhibits resistance to intracellular killing over 24 hours, does not germinate, and inflicts minimal damage to the host cell. Nonetheless, viable fungal spores of L. corymbifera induced early production of the pro-inflammatory cytokine IL-1β, and late release of TNF-α and IL-6 by human monocytes. Moreover, we revealed that IL-1β production predominantly depends on Toll-like receptors (TLRs) priming, especially via TLR4, while TNF-α is secreted via C-type lectin receptors (CTLs), and IL-6 is produced by synergistic activation of TLRs and CTLs. All these signaling pathways lead to the activation of NF-kB, a transcription factor that not only regulates the inflammatory response but also the apoptotic fate of monocytes during infection with L. corymbifera. Collectively, our findings provide new insights into the host-pathogen interactions, which may serve for future therapies to enhance the host inflammatory response to L. corymbifera.

Rhino-Orbital-Cerebral Mycosis and Extranodal Natural Killer or/and T-Cell Lymphoma, Nasal Type

Background

Extranodal natural killer/T-cell lymphoma, nasal type is a syndrome of middle face destruction with an association to Epstein-Barr virus. Fungi have been recovered from the diseased tissue now and then but were often seen as a lymphoma-associated secondary infection. However, there are ENKTL-NT cases with the recoveries of fungi and complete recovery with antifungal therapy, which are quite similar to rhino-orbital-cerebral mycosis (ROCM) that often confuses the physicians.

Methods

We searched Medline for English-language manuscripts limited to “human” and “case reports,” “letters,” “reviews,” and “clinical conferences” from 1966 to 2022. We used MeSH terms “lymphoma, extranodal nk-t-cell” [MeSH Terms] or “lethal midline granuloma” [MeSH Terms], in combination with MeSH terms “microbiology” [subheading] or “microbiology” [all fields] or “fungi” [all fields] or “fungi” [MeSH Terms] for ENKTL-NT with infections. We used MeSH terms “Mycoses” in combination with “Nose” [Mesh] OR “Orbital Diseases” [Mesh] for rhino-orbital-cerebral fungal infections.

Results

We appraised 149 included articles and extracted references related to ENKTL-NT and/or ROCM. Themes and subcategories were subsequently derived. Our findings revealed that ROCM and ENKTL-NT are characterized by progressive and destructive ulcers in the midline face or rhino-orbital structures. ROCM is mainly caused by fungi in the order of Mucorales, and ENKTL-NT is usually associated with Epstein-Barr virus and sometimes fungi. Radiologically, both are characterized by non-specific features of sinusitis, soft tissue infection, and necrosis. Pathologically, ROCM and ENKTL-NT share the same characteristics of inflammation, necrosis, and granuloma. ROCM is characterized by the detection of fungi in tissue, while ENKTL-NT is typically positive for NK/T-cell markers and cytotoxic granule-associated proteins, proliferation, and vascular damage of angioinvasion, which could be incited by Mucor irregularis and Rhizopus arrhizus in patients and mice.

Conclusion

ENKTL-NT and ROCM share many similarities in clinical presentations, radiology, and histopathology, and might have the same etiology. This may explain why the two diseases are tangled together in the reported cases, and suggests the role that the fungi may play in the development of these ENKTL-NT/ROCM diseases. The reason why ENKTL-NT and ROCM are sometimes confused is that the main pathogens of ROCM, Mucor irregularis and Rhizopus arrhizus, are the fungal causative agents of ENKTL-NT.

Case Report: Metagenomics Next-Generation Sequencing for Diagnosing Cerebral Infarction and Infection Caused by Hematogenous Disseminated Mucormycosis in a Patient With Acute Lymphoblastic Leukemia

Disseminated mucormycosis, a serious complication, is associated with high mortality in patients with acute leukemia after chemotherapy. Blood cultures are always negative because of recurrent empirical antifungal treatments. The identification of pathogens is important for diagnosis and therapy. In this case report, we diagnosed culture-negative disseminated mucormycosis with Rhizomucor miehei infection leading to cerebral infarction in a patient with leukemia using metagenomics next-generation sequencing (mNGS) form peripheral blood, cerebral spinal fluid, and bronchoalveolar lavage fluid. mNGS technology can be applied to precisely diagnose culture-negative disseminated mucormycosis.

Cerebral vasculitis caused by Talaromyces marneffei and Aspergillus niger in a HIV-positive patient: a case report and literature review

Cerebral vasculitis is a long-standing but flourishing and fadeless research topic. Infections are a frequent cause of cerebral vasculitis, vital to diagnose due to involvement of specific anti-infection treatments. A 65-year-old man visited the hospital for his neurological symptoms without obvious inducements. After admission, radiological examination and comprehensive conventional microbiological tests (CMTs) revealed suspected intracranial infectious vasculitis. Metagenomic next-generation sequencing (mNGS) and reverse transcription-polymerase chain reaction further confirmed that his cerebral vasculitis was caused by Talaromyces marneffei (T. marneffei) and Aspergillus niger (A. niger) co-infection. The patient’s final diagnosis changed from initial herpetic encephalitis, due to the past history of cephalosome and facial herpes and non-significant antiviral therapeutic effects, to fungal cerebral vasculitis. The patient was discharged after use of targeted antifungal therapies on day 18 of his admission, and his associated symptoms disappeared completely at follow-up 3 weeks later. We first illustrated the presence of uncommon cerebral vasculitis caused by T. marneffei and A. niger in a human immunodeficiency virus-positive patient. In clinically suspected patients with infectious cerebral vasculitis, mNGS should be performed to detect potential pathogens if CMTs may not provide useful pathogenic clues, highlighting the importance of mNGS in the diagnosis and treatment of infectious diseases.

Mucormycosis in COVID-19 pandemic: Risk factors and linkages

Mucormycosis is a serious and potentially fatal fungal infection caused by a type of rare but opportunistic fungal pathogen called mucormycetes. Recently, mucormycosis, also known as black fungus, made severe chaos in India during the second wave (between April and June 2021) of the tragical COVID-19 epidemic by its sudden and devastating surge with up to 50% mortality rate. While the exact cause of its sharp rise suddenly and specifically during the second wave still remains debatable, it has been noted that the people who are diabetic and have recovered from COVID-19 infection are more predisposed to mucormycosis. Nevertheless, the precise reason and mechanism(s) underlying the surge of this deadly infection needs to be investigated to comprehend its pathogenesis and pathological elements and discover rationale preventative/ therapeutic solutions. It is speculated that the indiscriminate use of steroids, antibiotics and zinc as a self-medication practice that increased during the COVID-19 epidemic may have promoted the dysbiosis of gut microbiota thereby inducing immune-suppression and making the risk group highly susceptible to this mycotic disease. In these contexts, this timely article attempts to contemplate and discuss some of the possible factors and potential mechanisms that can help to understand and explain the conundrum of sudden, steep and deadly upsurge of mucormycosis infections during the second wave of COVID-19 epidemic.

Host Immune Defense upon Fungal Infections with Mucorales: Pathogen-Immune Cell Interactions as Drivers of Inflammatory Responses

During the last few decades, mucormycosis has emerged as one of the most common fungal infections, following candidiasis and aspergillosis. The fungal order responsible for causing mucormycosis is the Mucorales. The main hallmarks of this infection include the invasion of blood vessels, infarction, thrombosis, and tissue necrosis, which are exhibited at the latest stages of the infection. Therefore, the diagnosis is often delayed, and the rapid progression of the infection severely endangers the life of people suffering from diabetes mellitus, hematological malignancies, or organ transplantation. Given the fact that mortality rates for mucormycosis range from 40 to 80%, early diagnosis and novel therapeutic strategies are urgently needed to battle the infection. However, compared to other fungal infections, little is known about the host immune response against Mucorales and the influence of inflammatory processes on the resolution of the infection. Hence, in this review, we summarized our current understanding of the interplay among pro-inflammatory cytokines, chemokines, and the host-immune cells in response to mucoralean fungi, as well as their potential use for immunotherapies.

Retrospective Clinical Study of Eighty-One Cases of Intracranial Mucormycosis

Background:

Fungal infections of the central nervous system, especially cerebral mucormycosis or brain abscess are very rare.Cerebral mucormycosis is a rare disease. It is not an independent disease, but a secondary opportunistic infectious disease.

Materials and methods:

This study has collected the data of 81 cases of intracranial mucormycosis from 28 Chinese hospitals, within 37 years, as well as reviewed the literatures and retrospectively analyzed and summarized this disease's background, clinical classifications, risk factors, pathology, clinical manifestations, diagnosis, treatment, and prognosis.

Results:

The 81 IM cases were aged between 15 days (the youngest) and 79 years (oldest), with a mean age of 41.6 years. Among them, 12 cases were <1 year old (the infant group), six cases were within one to 13 years old (the children group), and 63 cases were >14 years old (the adult group ). 45 cases were male and 36 were female, with a male/female ratio of 1.25:1.0. The shortest duration of the disease was three days, and the longest was 248 days.

Conclusions:

This study helped to realize an early diagnosis and treatment, improve the cure rate, and reduce mortality.

Mucormycoses caused by Lichtheimia species

Mucormycoses are life-threatening infections with fungi from the order Mucorales (Mucoromycotina). Although mucormycoses are uncommon compared to other fungal infections, e.g. aspergillosis and candidiasis, the number of cases is increasing especially in immunocompromised patients. Lichtheimia (formerly Absidia) species represent the second to third most common cause of mucormycoses in Europe. This mini review presents current knowledge about taxonomy and clinical relevance of Lichtheimia species. In addition, clinical presentation and risk factors will be discussed. Proper animal infection models are essential for the understanding of the pathogenesis and the identification of virulence factors of fungal pathogens. To date, several animal models have been used to study Lichtheimia infection. A brief overview of the different models and the main conclusions from the infection experiments is summarised in this review.

Wound infection caused by Lichtheimia ramosa due to a car accident

A 32-year-old immunocompetent man sustained severe traumas contaminated with organic material due to a car accident. An infection caused by Lichtheimia ramosa at the site of contamination was early diagnosed and cured by multiple surgical debridement and daily cleansing with antiseptic solution only.

Zygomycetes infections in pediatric hematology oncology patients: a case series and review of the literature

Fungi from the Zygomycetes class are increasingly recognized causes of infection in immunosuppressed children, but no comprehensive literature review and few case series have been published on the topic. A case series of 6 pediatric oncology patients with Zygomycetes infections cared for at our institution was constructed, and a concurrent search of the English language literature for Zygomycetes infections in children with oncologic disorders was undertaken. Our case series described 6 patients (5 male) between the ages of 2.5 and 19.5 years. One patient was diagnosed with rhinocerebral disease, 2 with rhinosinusitis, 2 with pulmonary involvement, and 1 with a gastrointestinal presentation. Five patients survived. Our literature review identified 82 cases from 61 studies. The mean subject age was 10.8 years (1.4 to 21.0 y). About 92.7% of all patients suffered from some form of leukemia, with 70.7% suffering from acute lymphoblastic leukemia. Overall, 58.5% of reported patients survived, with individuals with disseminated disease showing the worst prognosis (68.2% mortality) and those with cutaneous disease the best (14.3% mortality). Survival is increasingly reported in the literature, perhaps as a result of improved diagnostic capabilities, increased physician awareness and increased reliance on adjunctive surgical therapy.

Cunninghamella Bertholletiae Infection (Mucormycosis) in a Patient with Acute T-cell Lymphoblastic Leukemia

Cunninghamella spp. are unusual opportunistic pathogens that have been identified with increased frequency in immunocompromised patients. Clinical infection by this fungus is almost always devastating and usually fatal. Infections with this group of organisms have been seen most frequently in patients with hematological malignancy. Here we report the case of a patient with acute leukemia who developed multiorganic failure as a consequence of hematological dissemination by Cunninghamella bertholletiae. The case highlights the mortality associated with this fungal infection in immunocompromised patients, confirms the risk factors associated with non-candida fungal infections and shows a clinical presentation mimicking myocardial infarct and cerebrovascular stroke.

Successful treatment of a giant isolated cerebral mucormycotic (zygomycotic) abscess using endoscopic debridement: case report and therapeutic considerations

BACKGROUND

Cerebral mucormycosis without rhino-orbital or systemic involvement is an extremely rare condition mostly associated with parenteral drug abuse.

CASE DESCRIPTION

We report the case of a 42-year-old woman who presented with hemiparesis of the left side and altered mental status. Neuroradiologic workup demonstrated an inflammatory lesion involving the right basal ganglia. Proton magnetic resonance spectroscopy demonstrated features consistent with a pyogenic abscess. Computed tomography-guided stereotactic biopsy led to the diagnosis of cerebral mucormycosis. Parenteral AMB-L treatment was conducted, but the patient worsened clinically, presenting with a complete hemiplegia, and cerebral magnetic resonance imaging (MRI) scans demonstrated a voluminous abscess formation. Then, under stereotactic guidance, a surgical endoscopic debridement of the abscess cavity associated with the placement of an Ommaya reservoir was performed. Systemic and intralesional treatment with AmB associated with an adjunctive immune therapy was conducted. At 3-year follow-up, the patient had recovered partially from her left hemiplegia, allowing her to walk without help, and cerebral MRI scans showed complete resorption of the abscess.

CONCLUSION

Our good results suggest that surgical endoscopic debridement associated with intravenous and intracavitary antifungal therapy might be valuable in treating voluminous deep-seated mucormycotic lesions.

Imaging of isolated cerebral mucormycosis. A report of three cases

Mucormycosis is a rare infection in immunosupressed patients caused by fungi from the family Mucoraceae. Three types of disease spread have been described: rhinocerebral, systemic and isolated. Isolated spread is the most uncommon form, usually resulting in death. It has been described in diabetics, immunosupressed patients and intravenous drug abusers. Neuroimaging can aid the diagnosis of this entity, but biopsy remains the only reliable method. Imaging findings of Mucormycosis include abscesses and hemorrhagic or ischemic infarcts, usually in the basal ganglia and frontal lobes. Single or multiple lesions have been described as well as meningoencephalitis. Understanding these findings can help to detect the infection in an early stage. We describe three cases of isolated cerebral mucormycosis; all of them were intravenous drug abusers with one patient also being HIV positive.

Isolated cerebral mucormycosis: Report of a case and review of the literature

Isolated cerebral mucormycosis is a rare but life-threatening infection that generally occurs in patients with intravenous drug abuse or immune deficiency. We report a case of primary cerebral mucormycosis in a healthy adult. Whole body autopsy in this case revealed cerebral mucormycosis with prominent vascular pathology and hemorrhagic necrosis. No nasal sinus, orbital or other primary locus of fungus infection was discovered. Review of the previously reported 30 cases of isolated cerebral mucormycosis revealed associated systemic predisposition in 11 patients and history of intravenous drug abuse in 17 cases. In the remaining two cases, the diagnosis of fungal infection was made only after surgical exploration. Early tissue diagnosis and the consequent surgical excision of the necrotic tissue and aggressive antifungal therapy might salvage life in this fatal condition.

Epidemiology and outcome of zygomycosis: a review of 929 reported cases

BACKGROUND

Zygomycosis is an increasingly emerging life-threatening infection. There is no single comprehensive literature review that describes the epidemiology and outcome of this disease.

METHODS

We reviewed reports of zygomycosis in the English-language literature since 1885 and analyzed 929 eligible cases. We included in the database only those cases for which the underlying condition, the pattern of infection, the surgical and antifungal treatments, and survival were described.

RESULTS

The mean age of patients was 38.8 years; 65% were male. The prevalence and overall mortality were 36% and 44%, respectively, for diabetes; 19% and 35%, respectively, for no underlying condition; and 17% and 66%, respectively, for malignancy. The most common types of infection were sinus (39%), pulmonary (24%), and cutaneous (19%). Dissemination developed in 23% of cases. Mortality varied with the site of infection: 96% of patients with disseminated disease died, 85% with gastrointestinal infection died, and 76% with pulmonary infection died. The majority of patients with malignancy (92 [60%] of 154) had pulmonary disease, whereas the majority of patients with diabetes (222 [66%] of 337) had sinus disease. Rhinocerebral disease was seen more frequently in patients with diabetes (145 [33%] of 337), compared with patients with malignancy (6 [4%] of 154). Hematogenous dissemination to skin was rare; however, 78 (44%) of 176 cutaneous infections were complicated by deep extension or dissemination. Survival was 3% (8 of 241 patients) for cases that were not treated, 61% (324 of 532) for cases treated with amphotericin B deoxycholate, 57% (51 of 90) for cases treated with surgery alone, and 70% (328 of 470) for cases treated with antifungal therapy and surgery. By multivariate analysis, infection due to Cunninghamella species and disseminated disease were independently associated with increased rates of death (odds ratios, 2.78 and 11.2, respectively).

CONCLUSIONS

Outcome from zygomycosis varies as a function of the underlying condition, site of infection, and use of antifungal therapy.

Fatal strokes in patients with rhino-orbito-cerebral mucormycosis and associated vasculopathy

Within a 10-y period, fatal strokes occurred during parenteral administration of amphotericin B and surgical debridement of paranasal sinuses in 6 pathologically verified cases of rhino-orbito-cerebral mucormycosis (ROCM). All patients had unnoticed type-2 diabetes mellitus without ketoacidosis. They presented with unilateral orbital cellulitis and cavernous sinus syndrome. Fatal malignant cerebral infarctions occurred in the carotid system in 5 patients, and in the basilar artery or its major branches in 2 patients. Accelerated thrombotic occlusion of the cavernous portion of the carotid artery or the basilar artery was likely to be due to mucormycosis associated-vasculopathy and diabetic vasculopathy. One patient died of massive subarachnoid hemorrhage following rupture of the mycotic aneurysm. Despite parenteral administration of amphotericin B, fatal outcome of ROCM in patients with unnoticed diabetes mellitus occurs due to mucormycosis-associated malignant strokes. To improve outcome, a combination of early radical debridement, ocular exenteration, parenteral and local administration of amphotericin B, and decompression craniotomy should be considered.

Improved outcome of zygomycosis in patients with hematological diseases?

Zygomycosis is an opportunistic fungal infection that is increasingly reported in hematological patients. We describe 2 cases of successfully treated rhino-cerebral zygomycosis and give an overview of 120 patients from the literature with underlying hematological or oncological disorders. These data document the improved survival in sinus (15/17 patients surviving) and cutaneous (6/9 patients surviving) disease. Hematological patients with pulmonary (9/30 patients surviving) or disseminated (4/38 patients surviving) zygomycosis still have a poor prognosis. The clinical course of sinus-orbital involvement (4/11 patients surviving) follows sinus-cerebral (2/3 patients surviving) or cerebral (3/6 patients surviving) disease. Besides deoxycholate amphotericin B (AmB) (24/62 patients surviving), patients seem to benefit from liposomal amphotericin B (L-AmB) (10/16 patients surviving) or sequential AmB/L-AmB treatment (6/8 patients surviving). Alternative treatment options lead only in a few patients to success.

Vascularites secondaires aux infections fongiques

THE FUNGI INCRIMINATED: Cerebral vascular lesions are frequently observed in the rhino-cerebral localisations of aspergillosis and mucormycosis, and during cerebral coccidioidomycosis, but far more rarely in neuro-meningeal cryptococcosis and histoplasmosis. Other fungi are occasionally at the origin of vasculitis. THE CONTEXT: Diagnosis is difficult to establish. It should be evoked in immunodepressed patients presenting with clinical and radiological manifestations of cerebral vasculitis. AS FAR AS TREATMENT IS CONCERNED: Treatment relies on antifungal therapy. Steroids and/or anticoagulants can be envisaged in some patients.

Mucormycosis and entomophthoramycosis: a review of the clinical manifestations, diagnosis and treatment

The class Zygomycetes is divided into two orders, Mucorales and Entomophthorales. These two orders produce dramatically different infections. Genera from the order Mucorales (Rhizopus, Mucor, Rhizomucor, Absidia, Apophysomyces, Cunninghamella and Saksenaea) cause an angioinvasive infection called mucormycosis. Mucormycosis presents with rhino-orbito-cerebral, pulmonary, disseminated, cutaneous, or gastrointestinal involvement. Immunocompromising states such as haematological malignancy, bone marrow or peripheral blood stem cell transplantation, neutropenia, solid organ transplantation, diabetes mellitus with or without ketoacidosis, corticosteroids, and deferoxamine therapy for iron overload predispose patients to infection. Mucormycosis in immunocompetent hosts is rare, and is often related to trauma. Mortality rates can approach 100% depending on the patient's underlying disease and form of mucormycosis. Early diagnosis, along with treatment of the underlying medical condition, surgery, and an amphotericin B product are needed for a successful outcome. Genera from the order Entomophthorales produce a chronic subcutaneous infection called entomophthoramycosis in immunocompetent patients. This infection occurs in tropical and subtropical climates. The genus Basidiobolus typically produces a chronic subcutaneous infection of the thigh, buttock, and/or trunk. Rarely, it has been reported to involve the gastrointestinal tract. The genus Conidiobolus causes a chronic infection of the nasal submucosa and subcutaneous tissue of the nose and face. This paper will review the clinical manifestations, diagnosis and treatment of mucormycosis and entomophthoramycosis.