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Global epidemiological data show that the incidence of invasive fungal disease (IFD) has increased in recent decades, with the rising frequency of infections caused by Aspergillus and Mucorales order species. The number and variety of patients at risk of IFD has also expanded, owing in part to advances in the treatment of hematologic malignancies and other serious diseases, including hematopoietic stem cell transplantation (HCT) and other therapies causing immune suppression. Isavuconazonium sulfate (active moiety: isavuconazole) is an advanced-generation triazole antifungal approved for the treatment of invasive aspergillosis and mucormycosis that has demonstrated activity against a variety of yeasts, moulds, and dimorphic fungi. While real-world clinical experience with isavuconazole is sparse in some geographic regions, it has been shown to be effective and well tolerated in diverse patient populations, including those with multiple comorbidities who may have failed to respond to prior triazole antifungal therapy. Isavuconazole may be suitable for patients with IFD receiving concurrent QTc-prolonging therapy, as well as those on venetoclax or ruxolitinib. Data from clinical trials are not available to support the use of isavuconazole prophylactically for the prevention of IFD or for the treatment of endemic IFD, such as those caused by Histoplasma spp., but real-world evidence from case studies suggests that it has clinical utility in these settings. Isavuconazole is an option for patients at risk of IFD, particularly when the use of alternative antifungal therapies is not possible because of toxicities, pharmacokinetics, or drug interactions.

During pulmonary mucormycosis, inhaled sporangiospores adhere to, germinate, and invade airway epithelial cells to establish infection. We provide evidence that HIF1α plays dual roles in airway epithelial cells during Mucorales infection. We observed an increase in HIF1α protein accumulation and increased expression of many known HIF1α-responsive genes during in vitro infection, indicating that HIF1α signaling is activated by Mucorales infection. Inhibition of HIF1α signaling led to a substantial decrease in the ability of R. delemar to invade cultured airway epithelial cells. Transcriptome analysis revealed that R. delemar infection induces the expression of many pro-inflammatory genes whose expression was significantly reduced by HIF1α inhibition. Importantly, pharmacological inhibition of HIF1α increased survival in a mouse model of pulmonary mucormycosis without reducing fungal burden. These results suggest that HIF1α plays two opposing roles during mucormycosis: one that facilitates the ability of Mucorales to invade the host cells and one that facilitates the ability of the host to mount an innate immune response.

An 8-y-old Pygora doe was presented to the University of California-Davis, Veterinary Medical Teaching Hospital because of non-healing facial swelling of 2-wk duration. The lesion grew despite medical treatment, causing discomfort masticating, little-to-no airflow from the right nasal passage, and led to euthanasia. On gross examination, a large facial mass with a draining tract through the skin and hard palate was identified. On section, the mass was brown-pink, homogeneous, and friable. Abscess-like masses were identified in the lungs and kidney. Histopathology of the face, including oral and nasal cavities, salivary glands, and lymph nodes, as well as the lung and kidney lesions, revealed large areas of necrosis with numerous wide ribbon-like, mostly aseptate, fungal hyphae consistent with zygomycetes. PCR for fungal organisms performed on formalin-fixed, paraffin-embedded tissue from the face identified Lichtheimia corymbifera (formerly Absidia corymbifera) of the order Mucorales and an Aspergillus sp. The lesion was suspected to have started either as a fungal rhinitis or dental feed impaction, subsequently spreading to the face and systemically to the lungs and kidney. We describe here the lesions associated with facial mucormycosis in a goat and present a literature review of L. corymbifera infection in veterinary species and fungal infections in goats.

DNA N6-adenine methylation (6mA) has recently gained importance as an epigenetic modification in eukaryotes. Its function in lineages with high levels, such as early-diverging fungi (EDF), is of particular interest. Here, we investigated the biological significance and evolutionary implications of 6mA in EDF, which exhibit divergent evolutionary patterns in 6mA usage. The analysis of two Mucorales species displaying extreme 6mA usage reveals that species with high 6mA levels show symmetric methylation enriched in highly expressed genes. In contrast, species with low 6mA levels show mostly asymmetric 6mA. Interestingly, transcriptomic regulation throughout development and in response to environmental cues is associated with changes in the 6mA landscape. Furthermore, we identify an EDF-specific methyltransferase, likely originated from endosymbiotic bacteria, as responsible for asymmetric methylation, while an MTA-70 methylation complex performs symmetric methylation. The distinct phenotypes observed in the corresponding mutants reinforced the critical role of both types of 6mA in EDF.

Mucormycosis, an invasive fungal infection caused by members of the order Mucorales, often progresses fulminantly if not recognized in a timely manner. This comprehensive review discusses the latest developments in diagnostic approaches for mucormycosis, from traditional histopathology and culture-based methods to advanced and emerging techniques such as molecular assays, imaging, serology, and metabolomics. We discuss challenges in the diagnosis of mucormycosis and emphasize the importance of rapid and accurate identification of this life-threatening infection. [ABSTRACT FROM AUTHOR]

The species diversity of early-diverging fungi has long lagged behind that of higher fungi, posing a significant obstacle to our comprehensive understanding of the fungal kingdom. Our ongoing research endeavors aim to address this gap by exploring the species diversity of early-diverging fungi in China. In this study, we describe three novel species within the Backusella, namely B. elliptica sp. nov., B. fujianensis sp. nov., and B. variispora sp. nov., based on phylogenetic and morphological analyses. In the phylogenetic analysis of the ITS (internal transcribed spacer), LSU (large subunit of ribosomal RNA gene), and RPB1 (RNA polymerase II largest subunit gene) regions, the B. elliptica and B. fujianensis cluster closely with B. gigacellularis, B. ovalispora, and B. solicola, and the B. variispora is closely related to B. locustae and B. pernambucensis. Morphologically, B. elliptica is distinguished by elliptical sporangiospores, as well as cylindrical and hemispherical columellae. The B. fujianensis is characterized by elliptical sporangiospores, and various types of columellae such as hemispherical, subglobose, depressed globose and conical. The B. variispora is characterized by subglobose to globose sporangiospores, as well as hemispherical, subglobose to globose columellae. Additionally, the sporangiophores are long and monopodially branched in B. elliptica and B. fujianensis, while short and simple or sympodially branched in B. variispora. Physiologically, the maximum growth temperatures of B. elliptica (32 °C), B. fujianensis (35 °C), and B. variispora were (35 °C) were determined. With the inclusion of these newly described taxa, the total number of Backusella species known from China now stands at 12. Finally, we provide a key to facilitate the morphological identification of Backusella species from Asia. [ABSTRACT FROM AUTHOR]

Background: During the coronavirus disease 2019 (COVD-19) pandemic, the incidence of mucormycosis also increased, especially affecting individuals who have had the COVID-19 infection in the past. Aims: The aim of the study is to assess risk factors and clinical and histopathological features of mucormycosis in post-COVID-19 cases. Methods: This is a retrospective study conducted in a tertiary care COVID-19-dedicated hospital, Dehradun, Uttarakhand, India, over a period of 2 months during the COVID-19 pandemic. All surgical specimens submitted for histopathology with a suspected diagnosis of mucormycosis were included. Histopathology was considered the gold standard. All histopathologically confirmed cases were studied in detail with respect to histopathology, clinico-radiological features, and microbiological results Results: Of 25 cases with clinical diagnosis of mucormycosis, nine were histopathologically confirmed as mucormycosis. Seven patients had diabetes, while two did not have any co-morbidity. The fungal load was heavy in 50% cases, and the proportion of necrosis was higher with diabetes mellitus, as compared to non-diabetic and non-co-morbidity patients. Angioinvasion (33.3% cases), soft-tissue invasion (44.4%), Splendor–Hoeppli phenomenon (44.4%), and neural invasion (11.1%) were also present. Mixed infection (Mucormycosis and Aspergillus species) was present in three of the cases who also had diabetes. The microbiological investigations were positive in only 55.5% cases. Conclusion: Post-COVID Mucormycosis has fatal outcomes. Early diagnosis and treatment are the key to successful treatment. Early and reliable diagnosis can be offered by histopathological examination.

The species within the family Cunninghamellaceae during an investigation of soil microfungi in Korea, in which three strains were isolated from Gangwon, Chungbuk, and Gyeongbuk provinces, designated as KNUF-22-121A, KNUF-22-126A, and KNUF-22-316, respectively. Because the morphological and molecular analyses of these three strains were identical, KNUF-22-316 underwent further detailed study. Phylogenetic analyses based on the concatenated nucleotide sequences of the internal transcribed spacer region and the large subunit 28S rRNA gene revealed that the strain belonged to the genus Absidia, but occupied a distinct phylogenetic position. The strain KNUF-22-316 was compared with closely related species Absidia radiata CGMCC 3.16257T and Absidia yunnanensis CGMCC 3.16259T, morphologically different with shorter sporangiophores, smaller sporangia and columellae, and the consistent presence of collars. Here, we provide a detailed description and images of this proposed new species, which we have named Absidia microsporangia sp. nov. [ABSTRACT FROM AUTHOR]

Deep sternal wound infection is a rare complication of cardiac surgery that is typically caused by skin resident flora, such as species of Staphylococcus and Streptococcus. Infections caused by fungi are less common and are generally caused by Candida species. Regardless of etiology, these infections are associated with significant morbidity and mortality. We present a case of postoperative mediastinitis that occurred following a 5-vessel coronary artery bypass graft and was caused by a filamentous fungus of the Rhizopus genus. The patient was treated with serial debridement, liposomal amphotericin B, and isavuconazonium and was discharged from the hospital in stable condition. Fungal mediastinitis is a rare entity, and clinicians must maintain a high level of suspicion to make the diagnosis. A fungal cause of postoperative mediastinitis should be considered in patients with negative bacterial cultures, uncontrolled diabetes, or current immunosuppression or those who present weeks after surgery with a subacute onset of symptoms. [ABSTRACT FROM AUTHOR]

Mucormycosis is a fungal infection caused by the order Mucorales from the class Zygomycetes. Among the genera within the order Mucorales, Rhizopus sp. is the genus most frequently causing infections. Mucorales fungi enter the human body in three ways: through inhalation of airborne spores, through broken skin, and through ingestion of contaminated food. Within the human body, the process is angioinvasive, leading to thrombosis and resulting in tissue necrosis. Currently, establishing a diagnosis is crucial for determining the patient’s prognosis, as it can reduce morbidity and mortality. The current diagnostic modes include direct examination, culture, histopathology, and molecular identification. Each of these methods has its advantages and disadvantages. However, for rapid diagnosis, molecular examination, either through PCR or RT PCR, is necessary. [ABSTRACT FROM AUTHOR]

The World Health Organization, in response to the growing burden of fungal disease, established a process to develop a fungal priority pathogens list (FPPL). This systematic review aimed to evaluate the epidemiology and impact of invasive fungal disease due to Mucorales. PubMed and Web of Science were searched to identify studies published between January 1, 2011 and February 23, 2021. Studies reporting on mortality, inpatient care, complications and sequelae, antifungal susceptibility, risk factors, preventability, annual incidence, global distribution, and emergence during the study time frames were selected. Overall, 24 studies were included. Mortality rates of up to 80% were reported. Antifungal susceptibility varied across agents and species, with the minimum inhibitory concentrations lowest for amphotericin B and posaconazole. Diabetes mellitus was a common risk factor, detected in 65%–85% of patients with mucormycosis, particularly in those with rhino-orbital disease (86.9%). Break-through infection was detected in 13.6%–100% on azole or echinocandin antifungal prophylaxis. The reported prevalence rates were variable, with some studies reporting stable rates in the USA of 0.094–0.117/10 000 discharges between 2011 and 2014, whereas others reported an increase in Iran from 16.8% to 24% between 2011 and 2015. Carefully designed global surveillance studies, linking laboratory and clinical data, are required to develop clinical breakpoints to guide antifungal therapy and determine accurate estimates of complications and sequelae, annual incidence, trends, and global distribution. These data will provide robust estimates of disease burden to refine interventions and better inform future FPPL. [ABSTRACT FROM AUTHOR]

Summary: Background: Mucormycosis is a deadly invasive fungal infection recently included in the WHO priority pathogen list. Here we sought to describe epidemiological trends of mucormycosis in France, and to evaluate factors associated with mortality. Methods: From 2012 to 2022, we implemented a nationwide prospective surveillance programme for mucormycosis in France, focusing on epidemiology, species, seasonal variations. Factors associated with 3-month mortality were studied by univariable and multivariable logistic regression. Findings: Among 550 cases of mucormycosis, the main underlying conditions were haematological malignancy (HM, 65.1%, 358/550), trauma (8%, 44/550), diabetes (7.5%, 41/550) and solid-organ transplants (6.5%, 36/550). Site of infection was pulmonary in 52.4% (288/550), rhinocerebral in 14.5% (80/550), and cutaneo-articular in 17.1% (94/550). Main species identified were Rhizopus arrhizus (21%, 67/316), Rhizopus microsporus (13.6%, 43/316), Lichtheimia corymbifera and Mucor circinelloides (13.3%, 42/316 each), Rhizomucor pusillus (12%, 38/316), and Lichtheimia ramosa (10.8%, 34/316). We found associations between underlying condition, site of infection, and infecting species, including a previously undescribed triad of trauma, cutaneo-articular localisations, and L. ramosa/M. circinelloides. Diagnostic contribution of Polymerase Chain Reaction (PCR) increased from 16% (4/25) in 2012 to 91% (61/67) in 2022, with more than 50% of diagnoses relying solely on PCR in 2022. We also found seasonal variations with relatively more cases in autumn. Ninety-day mortality was 55.8% (276/495). Independent prognostic factors were age, diagnosis in Intensive Care Unit (ICU), and HM while diagnosis after 2015 (i.e. large implementation of PCR) and surgery were associated with reduced mortality. Interpretation: This study reveals major mucormycosis epidemiological changes in France, with a large predominance of HM patients, and a parallel between PCR multicentre implementation and improved prognosis. We also evidence new associations between species, localisations and risk factors, as well as seasonal variations. Funding: Recurrent financial support from Santé Publique France and Institut Pasteur.

ABSTRACT Filamentous fungi present significant health hazards to immunocompromised individuals globally; however, the prompt and precise identification of them during infection remains challenging. In this study, a TaqMan probe-based multiplex real-time PCR (M-qPCR) assay was developed to detect simultaneously the target genes of four important pathogenic filamentous fungi: ANXC4 gene of Aspergillus fumigatus, EF1-α gene of Fusarium spp., mitochondrial rnl gene of Mucorales, and hcp100 gene of Histoplasma capsulatum. In this M-qPCR assay, the limit of detection (LoD) to all four kinds of fungi was 100 copies and the correlation coefficients (R2) were above 0.99. The specificity of this assay is 100%, and the minimum detection limit is 100 copies/reaction. In conclusion, an M-qPCR detection assay was well established with high specificity and sensitivity for rapid and simultaneous detection on four important filamentous fungi in the clinic.IMPORTANCEWorld Health Organization developed the first fungal priority pathogens list (WHO FPPL) in 2022. Aspergillus fumigatus, Mucorales, Fusarium spp., and Histoplasma spp. are the four types of pathogenic fungi with filamentous morphology in the critical priority group and high priority group of WHO FPPL. These four filamentous fungal infections have become more common and severe in immunocompromised patients with the increase in susceptible populations in recent decades, which resulted in a substantial burden on the public health system. However, prompt and precise identification of them during infection remains challenging. Our study established successfully a TaqMan probe-based multiplex real-time qPCR assay for four clinically important filamentous fungi, A. fumigatus, Fusarium spp., Mucorales, and Histoplasma capsulatum, with high sensitivity and specificity, which shows promising potential for prompt and precise diagnosis against fungal infection.

The respiratory tree maintains sterilizing immunity against human fungal pathogens. Humans inhale ubiquitous filamentous molds and geographically restricted dimorphic fungal pathogens that form small airborne conidia. In addition, pathogenic yeasts, exemplified by encapsulated Cryptococcus species, and Pneumocystis pose significant fungal threats to the lung. Classically, fungal pneumonia occurs in immune compromised individuals, specifically in patients with HIV/AIDS, in patients with hematologic malignancies, in organ transplant recipients, and in patients treated with corticosteroids and targeted biologics that impair fungal immune surveillance in the lung. The emergence of fungal co-infections during severe influenza and COVID-19 underscores the impairment of fungus-specific host defense pathways in the lung by respiratory viruses and by medical therapies to treat viral infections. Beyond life-threatening invasive syndromes, fungal antigen exposure can exacerbate allergenic disease in the lung. In this review, we discuss emerging principles of lung-specific antifungal immunity, integrate the contributions and cooperation of lung epithelial, innate immune, and adaptive immune cells to mucosal barrier immunity, and highlight the pathogenesis of fungal-associated allergenic disease. Improved understanding of fungus-specific immunity in the respiratory tree has paved the way to develop improved diagnostic, pre-emptive, therapeutic, and vaccine approaches for fungal diseases of the lung.

The species within the family Cunninghamellaceae during an investigation of soil microfungi in Korea, in which three strains were isolated from Gangwon, Chungbuk, and Gyeongbuk provinces, designated as KNUF-22-121A, KNUF-22-126A, and KNUF-22-316, respectively. Because the morphological and molecular analyses of these three strains were identical, KNUF-22-316 underwent further detailed study. Phylogenetic analyses based on the concatenated nucleotide sequences of the internal transcribed spacer region and the large subunit 28S rRNA gene revealed that the strain belonged to the genus Absidia, but occupied a distinct phylogenetic position. The strain KNUF-22-316 was compared with closely related species Absidia radiata CGMCC 3.16257T and Absidia yunnanensis CGMCC 3.16259T, morphologically different with shorter sporangiophores, smaller sporangia and columellae, and the consistent presence of collars. Here, we provide a detailed description and images of this proposed new species, which we have named Absidia microsporangia sp. nov.

La mucormicosis es una infección fúngica oportunista e invasiva, con una elevada tasa de mortalidad. Se ha detectado principalmente en pacientes con COVID-19, especialmente en personas con enfermedades concomitantes como la diabetes mellitus. La prevalencia de las mucormicosis es de 0,005 a 1,7 casos por millón de habitantes y ha ido en aumento en países como India y Pakistán; puede afectar diferentes órganos y su forma clínica refleja el mecanismo de transmisión. Entre las formas frecuentes están la rino-orbital-cerebral y la pulmonar, por ello, debe sospecharse mucormicosis en los pacientes con lesiones necróticas en mucosas o piel. Se presenta el caso de un paciente con antecedentes de diabetes mellitus que fue diagnosticado con mucormicosis oral asociada a la COVID-19.

Purpose: Invasive fungal sinusitis (IFS) is associated with high rates of morbidity and mortality and often presents with orbital apex syndrome. Prompt diagnosis and management are crucial to prevent irreversible visual loss. We report a case of an immunosuppressed patient with rapidly progressive severe visual loss associated with frontal lobe cerebritis and leptomeningitis related to IFS, causing an adjacent compressive inflammatory optic neuropathy, which was treated successfully by large-dose corticosteroids. Observations: A 29-year-old woman with acute myeloid leukemia status post chemotherapy presented with right-sided headaches and periorbital swelling. Her examination was significant for subjective red desaturation and trace right eyelid edema and ptosis. The remainder of her initial ocular examination was normal. Her labs demonstrated neutropenia and thrombocytopenia. Imaging of the brain and orbits was concerning for extensive sinus disease with intracranial extension. An urgent multi-sinus and optic nerve decompression was performed given concern for compressive optic neuropathy, and the biopsy was consistent with invasive fungal infection. Despite aggressive antifungal treatment, vision in her right eye decreased rapidly to counting fingers. No optic nerve abnormalities were observed on serial MRIs, but adjacent inferior frontal lobe enhancement was present. After a vigorous debate in a multidisciplinary meeting, her severe vision loss was attributed to cerebritis causing an adjacent compressive inflammatory optic neuropathy, and large-dose intravenous (IV) steroid treatment was initiated while maintaining systemic antifungal therapy. Remarkably, she had a full recovery of her vision. Conclusions and importance: Severe vision loss in IFS can occur due to compressive inflammatory optic neuropathy without direct fungal invasion as a contributing factor. Timely and effective intervention is crucial in preventing vision loss. Large-dose steroid therapy may be a potential treatment option for immunocompromised patients with invasive fungal sinusitis and intracranial invasion, provided strict fungal infection control measures are in place.

Mucormycosis is an invasive fungal infection caused by certain members of the fungal order of Mucorales. The species most frequently identified as the etiological agents of mucormycosis belong to the genera Rhizopus, Lichtheimia, and Mucor. The frequency of systemic mucormycosis has been increasing, mainly because of increasing numbers of susceptible patients. Furthermore, Mucorales display intrinsic resistance to the majority of routinely used antifungal agents (e.g., echinocandins and short-tailed azoles), which limits the number of possible therapeutic options. All the above-mentioned issues urge the improvement of molecular identification methods and the discovery of new antifungal targets and strategies. Spore coat proteins (CotH) constitute a kinase family present in many pathogenic bacteria and fungi and participate in the spore formation in these organisms. Moreover, some of them can act as virulence factors being receptors of the human GRP78 protein during Rhizopus delemar-induced mucormycosis. We identified 17 cotH-like genes in the Mucor lusitanicus genome database. Successful disruption of five cotH genes in Mucor was performed using the CRISPR-Cas9 system. The CotH3 and CotH4 proteins play a role in adaptation to different temperatures as well as in developing the cell wall structure. We also show CotH4 protein is involved in spore wall formation by affecting the total chitin content and, thus, the composition of the spore wall. The role of CotH3 and CotH4 proteins in virulence was confirmed in two invertebrate models and a diabetic ketoacidosis (DKA) mouse model. IMPORTANCE Current treatment options for mucormycosis are inadequate, resulting in high mortality rates, especially among immunosuppressed patients. The development of novel therapies for mucormycosis has been hampered by lack of understanding of the pathogenetic mechanisms. The importance of the cell surface CotH proteins in the pathogenesis of Rhizopus-mediated mucormycosis has been recently described. However, the contribution of this family of proteins to the virulence of other mucoralean fungi and their functionality in vital processes remain undefined. Through the use of the CRISPR-Case9 gene disruption system, we demonstrate the importance of several of the CotH proteins to the virulence of Mucor lusitanicus by using three infection models. We also report on the importance of one of these proteins, CotH4, to spore wall formation by affecting chitin content. Therefore, our studies extend the importance of CotH proteins to Mucor and identify the mechanism by which one of the CotH proteins contributes to the development of a normal fungal cell wall, thereby indicating that this family of proteins can be targeted for future development of novel therapeutic strategies of mucormycosis.

Mucormycosis (MCR) is an emerging and frequently lethal fungal infection caused by the Mucorales family, with Rhizopus, Mucor, and Lichtheimia, accounting for > 90% of all cases. MCR is seen in patients with severe immunosuppression such as those with hematologic malignancy or transplantation, Diabetes Mellitus (DM) and diabetic ketoacidosis (DKA) and immunocompetent patients with severe wounds. The recent SARS COV2 epidemy in India has resulted in a tremendous increase in MCR cases, typically seen in the setting of uncontrolled DM and corticosteroid use. In addition to the diversity of affected hosts, MCR has pleiotropic clinical presentations, with rhino-orbital/rhino-cerebral, sino-pulmonary and necrotizing cutaneous forms being the predominant manifestations. Major insights in MCR pathogenesis have brought into focus the host receptors (GRP78) and signaling pathways (EGFR activation cascade) as well as the adhesins used by Mucorales for invasion. Furthermore, studies have expanded on the importance of iron availability and the complex regulation of iron homeostasis, as well as the pivotal role of mycotoxins as key factors for tissue invasion. The molecular toolbox to study Mucorales pathogenesis remains underdeveloped, but promise is brought by RNAi and CRISPR/Cas9 approaches. Important recent advancements have been made in early, culture-independent molecular diagnosis of MCR. However, development of new potent antifungals against Mucorales remains an unmet need. Therapy of MCR is multidisciplinary and requires a high index of suspicion for initiation of early Mucorales-active antifungals. Reversal of underlying immunosuppression, if feasible, rapid DKA correction and in selected patients, surgical debulking are crucial for improved outcomes.

Cutaneous mucormycosis is a rapidly advancing fungal infection that most commonly occurs due to airborne spread or direct inoculation and requires early detection and prompt treatment for optimal survival. Major risk factors include diabetes, transplantations, malignancies, surgical procedures, and HIV. Diagnostic criteria are based on microscopy and culture. We present an immunocompromised patient with cutaneous mucormycosis that developed in a peristomal ulcer following a hemicolectomy procedure. Histopathologic evaluation was indicative of mucormycosis. Intravenous posaconazole treatment was initiated, but unfortunately, the patient's condition deteriorated and he passed away.

During the COVID-19 pandemic, a significant increase in cases of mucormycosis was observed in COVID-19 patients, especially in India, but not exclusively. The presented cases highlight the heterogeneous nature of mucormycosis, emphasizing the importance of recognizing predisposing factors, such as immunosuppression, due to comorbidities or medication. Diagnosing mucormycosis poses a challenge due to nonspecific clinical manifestations, requiring a multidisciplinary approach for accurate diagnosis. Treatment involves a multi-pronged approach centered around the early initiation of antifungal therapy alongside surgical intervention and the management of underlying conditions, with an emphasis on controlling immunosuppression. Understanding the relationship between COVID-19 and predisposing factors for mucormycosis is fundamental for developing prevention and treatment strategies. [ABSTRACT FROM AUTHOR]

Mucormycosis is a perilous fungal infection that primarily affects individuals with compromised immune systems. The escalating incidence of conditions such as diabetes, cancer and the use of immunosuppressive drugs renders more individuals susceptible to contracting this disease. This report delves into the case of a 45-year-old woman from Tanzania with diabetes who succumbed to rhino-cerebral mucormycosis. Despite aggressive treatment, which often involves disfiguring surgical debridement and administration of antifungal drugs, the mortality rate remains high. Additionally, we present a comprehensive literature review of the various clinical aspects of Mucormycosis, an uncommon yet fatal condition. [ABSTRACT FROM AUTHOR]

Mucormycosis is a disease with a high percentage of mortality. This opportunistic disease is caused by pathogens of the Zygomicota family of the order Mucorales, which affect considerably, mainly immunocompromised patients. We present the case of a patient approached at the Hospital Central Militar de México, diagnosed with rhino-orbito-cerebral mucormycosis, with histopathological report of non-septated hyaline hyphae of 90 º, referring to the aforementioned diagnosis. A multidisciplinary approach to the pathology was carried out with diagnosis, timely medical and surgical treatment, achieving a favorable evolution and prognosis in a condition whose outcome is usually fatal. [ABSTRACT FROM AUTHOR]

Mucorales are a large order of ubiquitous saprophytic zygomycete fungi and act as opportunistic pathogens in humans. In pediatric patients, little is known about the role of Mucorales in airway colonization and infection or their role as contaminants of respiratory samples. Currently, polymerase chain reaction (PCR) is the most sensitive mode of detection Mucorales in clinical specimen. In this study, we aimed to determine the prevalence of Mucorales in bronchoalveolar lavage samples (BAL) from a large, diverse group of pediatric patients. We performed commercial Mucorales PCR (MucorGenius®, Pathonostics, Maastricht, NL, USA) on 102 thawed BAL samples of 100 patients. Mucorales PCR was negative in all samples. Our data suggest that Mucorales spp. have a low prevalence in paediatric airways and do not frequently contaminate pediatric BAL samples. [ABSTRACT FROM AUTHOR]

In this present study, potential oleaginous Mucorales fungi that have been isolated from fruits from local markets in Sleman, Indonesia, were screened for lipid production. A total of six fungal cultures were isolated and screened using a semisynthetic medium with glucose as a carbon source and a limited nitrogen supply. The highest lipid content was observed in isolate JR 1.1, up to 43.46% and 3.28 g/L lipid yield. Therefore, it was selected for molecular identification and fatty acid analysis. The result showed that JR 1.1 was identified as Mucor irregularis. The fatty acid profile of JR 1.1 showed 16.89% palmitoleic acid, 4.85% oleic acid, 45.22% linolenic acid, 30.79% gamma-linolenic acid, and 2.25% other fatty acids. It can be concluded that M. irregularis JR 1.1 is a potential strain to be used as a lipid producer for biodiesel feedstock. Further studies are recommended to optimize lipid productivity and improve fatty acid composition. [ABSTRACT FROM AUTHOR]

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Mucormycosis is a highly aggressive angio-invasive disease of humans caused by Mucorales fungi. Prior to the COVID-19 pandemic, mucormycosis was a rare mycosis typically seen in immunocompromised patients with hematological malignancies or in transplant recipients. During the second wave of the pandemic, there was a dramatic increase in the disease, especially in India where a unique set of circumstances led to large numbers of life-threatening and disfiguring rhino-orbital-cerebral mucormycosis (ROCM) infections. The review examines mucormycosis as a super-infection of COVID-19 patients, and the risk factors for COVID-19-associated mucormycosis (CAM) that drove the ROCM epidemic in India. The limitations of current diagnostic procedures are identified, and the measures needed to improve the speed and accuracy of detection discussed. Despite increased awareness, global healthcare systems remain unprepared for further outbreaks of ROCM. Current diagnosis of the disease is slow and inaccurate, negatively impacting on patient survival. This is most evident in low- to middle-income countries which lack suitably equipped diagnostic facilities for rapid identification of the infecting pathogens. Rapid antigen testing using point-of-care lateral-flow assays could potentially have aided in the quick and accurate diagnosis of the disease, allowing earlier intervention with surgery and Mucorales-active antifungal drugs. [ABSTRACT FROM AUTHOR]

ABSTRACT Mucormycoses are emerging fungal infections caused by a variety of heterogeneous species within the Mucorales order. Among the Mucor species complex, Mucor circinelloides is the most frequently isolated pathogen in mucormycosis patients and despite its clinical significance, there is an absence of established genome manipulation techniques to conduct molecular pathogenesis studies. In this study, we generated a spontaneous uracil auxotrophic strain and developed a genetic transformation procedure to analyze molecular mechanisms conferring antifungal drug resistance. With this new model, phenotypic analyses of gene deletion mutants were conducted to define Erg3 and Erg6a as key biosynthetic enzymes in the M. circinelloides ergosterol pathway. Erg3 is a C-5 sterol desaturase involved in growth, sporulation, virulence, and azole susceptibility. In other fungal pathogens, erg3 mutations confer azole resistance because Erg3 catalyzes the production of a toxic diol upon azole exposure. Surprisingly, M. circinelloides produces only trace amounts of this toxic diol and yet, it is still susceptible to posaconazole and isavuconazole due to alterations in membrane sterol composition. These alterations are severely aggravated by erg3Δ mutations, resulting in ergosterol depletion and, consequently, hypersusceptibility to azoles. We also identified Erg6a as the main C-24 sterol methyltransferase, whose activity may be partially rescued by the paralogs Erg6b and Erg6c. Loss of Erg6a function diverts ergosterol synthesis to the production of cholesta-type sterols, resulting in resistance to amphotericin B. Our findings suggest that mutations or epimutations causing loss of Erg6 function may arise during human infections, resulting in antifungal drug resistance to first-line treatments against mucormycosis.IMPORTANCEThe Mucor species complex comprises a variety of opportunistic pathogens known to cause mucormycosis, a potentially lethal fungal infection with limited therapeutic options. The only effective first-line treatments against mucormycosis consist of liposomal formulations of amphotericin B and the triazoles posaconazole and isavuconazole, all of which target components within the ergosterol biosynthetic pathway. This study uncovered M. circinelloides Erg3 and Erg6a as key enzymes to produce ergosterol, a vital constituent of fungal membranes. Absence of any of those enzymes leads to decreased ergosterol and consequently, resistance to ergosterol-binding polyenes such as amphotericin B. Particularly, losing Erg6a function poses a higher threat as the ergosterol pathway is channeled into alternative sterols similar to cholesterol, which maintain membrane permeability. As a result, erg6a mutants survive within the host and disseminate the infection, indicating that Erg6a deficiency may arise during human infections and confer resistance to the most effective treatment against mucormycoses.

Mucormycosis, a rare but life-threatening fungal infection, poses significant challenges in clinical management, particularly in patients with uncontrolled diabetes mellitus. This case report presents the clinical journey of a 44-year-old woman who developed a rapidly progressing Mucorales infection following a domestic knife injury. Her condition, complicated by diabetic ketoacidosis and co-infection with Candida albicans, led to severe hand phlegm and sepsis. Despite aggressive intervention, the infection continued to advance, ultimately resulting in the patient’s demise.

Mucormycosis is a progressive and life-threatening disease that has been increasingly reported in patients infected by coronavirus diseases 2019 (COVID-19). We describe a case of rhino-orbital mucormycosis with central nervous system involvement resulting in bilateral blindness and intracranial extension in a patient with uncontrolled diabetes mellitus (DM) and mild COVID-19 infection. A 35-year-old obese male, recently diagnosed with DM, presented to the emergency department suffering from dizziness, headache, speech difficulty, and facial weakness. His glycosylated hemoglobin was 10.4% and his reverse transcriptase–polymerase chain reaction (PCR) test came positive for COVID-19. Ocular examination revealed left eye proptosis, ophthalmoplegia, and lid edema with no ocular movement. Imaging studies showed pansinusitis and periorbital and orbital cellulitis with intracranial involvement. Histopathology and biopsy examination confirmed mucormycosis. Medical management included glucose control and liposomal amphotericin B therapy. Septoplasty and functional endoscopic sinus surgery was performed as emergency procedures. The patient survived with bilateral blindness. In this case, we described the importance of considering mucormycosis in COVID-19 patients with uncontrolled diabetes, particularly those presenting with sinusitis, headache, and orbital edema symptoms. Despite intensive antifungal therapy and surgical intervention, it is a serious opportunistic fungal infection associated with long-term complications.

Mucormycosis, an invasive fungal infection caused by members of the order Mucorales, often progresses fulminantly if not recognized in a timely manner. This comprehensive review discusses the latest developments in diagnostic approaches for mucormycosis, from traditional histopathology and culture-based methods to advanced and emerging techniques such as molecular assays, imaging, serology, and metabolomics. We discuss challenges in the diagnosis of mucormycosis and emphasize the importance of rapid and accurate identification of this life-threatening infection.

Les voies respiratoires sont exposées quotidiennement à l'inhalation d'une grande diversité de pathogènes fongiques. Chez un individu immunocompétent sans pathologie respiratoire sous-jacente, cette exposition, dès lors qu'elle reste modérée, n'a aucune conséquence. En revanche, en cas d'altération de l'intégrité de l'arbre respiratoire et/ou de déficits immunitaires innés ou acquis, la pénétration d'agents fongiques dans le tractus respiratoire est susceptible d'entraîner des pathologies diverses à la présentation clinique variable, depuis la pneumopathie localisée jusqu'à la mycose disséminée. Nous nous proposons dans cet article de passer en revue les principaux agents fongiques responsables de pathologies respiratoires. Nous détaillerons pour chaque pathogène ses principales caractéristiques épidémiologiques, les présentations cliniques et les modalités diagnostiques. The respiratory tract is exposed daily to inhalation of a wide variety of fungal pathogens. In an immunocompetent individual with no underlying respiratory pathology, this exposure, provided it remains moderate, has no consequences, but in the case of altered integrity of the respiratory tree and/or innate or acquired immune deficiencies, the penetration of fungal agents into the respiratory tract is likely to lead to a variety of pathologies with variable clinical presentation, from localized pneumopathy to disseminated mycosis. This article reviews the main fungal agents responsible for respiratory diseases. For each pathogen, we will detail its main epidemiological characteristics, the clinical presentations and the diagnostic procedures. [ABSTRACT FROM AUTHOR]

Background and Objectives: The mechanisms underlying COVID-19-associated pulmonary mucormycosis (CAPM) remain unclear. We use a transcriptomic analysis of the innate immune cells to investigate the host immune and metabolic response pathways in patients with CAPM. Patients and Methods: We enrolled subjects with CAPM (n = 5), pulmonary mucormycosis (PM) without COVID-19 (n = 5), COVID-19 (without mucormycosis, n = 5), healthy controls (n = 5) without comorbid illness and negative for SARS-CoV-2. Peripheral blood samples from cases were collected before initiating antifungal therapy, and neutrophils and monocytes were isolated. RNA sequencing was performed using Illumina HiSeqX from monocytes and neutrophils. Raw reads were aligned with HISAT-2 pipeline and DESeq2 was used for differential gene expression. Gene ontology (GO) and metabolic pathway analysis were performed using Shiny GO application and R packages (ggplot2, Pathview). Results: The derangement of core immune and metabolic responses in CAPM patients was noted. Pattern recognition receptors, dectin-2, MCL, FcR receptors and CLEC-2, were upregulated, but signalling pathways such as JAK-STAT, IL-17 and CARD-9 were downregulated; mTOR and MAP-kinase signalling were elevated in monocytes from CAPM patients. The complement receptors, NETosis, and pro-inflammatory responses, such as S100A8/A9, lipocalin and MMP9, were elevated. The major metabolic pathways of glucose metabolism--glycolysis/gluconeogenesis, pentose phosphate pathway, HIF signalling and iron metabolism-ferroptosis were also upregulated in CAPM. Conclusions: We identified significant alterations in the metabolic pathways possibly leading to cellular iron overload and a hyperglycaemic state. Immune responses revealed altered recognition, signalling, effector functions and a pro-inflammatory state in monocytes and neutrophils from CAPM patients. [ABSTRACT FROM AUTHOR]

Mucormycosis is known to be a rare opportunistic infection caused by fungal organisms belonging to the Mucorales order, which includes the Syncephalastrum species. These moulds are rarely involved in clinical diseases and are generally seen as contaminants in clinical laboratories. However, in recent years, case reports of human infections due to Syncephalastrum have increased, especially in immunocompromised hosts. In this study, we described two new Syncephalastrum species, which were isolated from human nails and sputum samples from two different patients. We used several methods for genomic and phenotypic characterisation. The phenotypic analysis relied on the morphological features, analysed both by optical and scanning electron microscopy. We used matrix-assisted laser desorption–ionization time-of-flight mass spectrometry, energy-dispersive X-ray spectroscopy, and BiologTM technology to characterise the proteomic, chemical mapping, and carbon source assimilation profiles, respectively. The genomic analysis relied on a multilocus DNA sequence analysis of the rRNA internal transcribed spacers and D1/D2 large subunit domains, fragments of the translation elongation factor-1 alpha, and the β-tubulin genes. The two novel species in the genus Syncephalastrum, namely S. massiliense PMMF0073 and S. timoneanum PMMF0107, presented a similar morphology: irregular branched and aseptate hyphae with ribbon-like aspects and terminal vesicles at the apices all surrounded by cylindrical merosporangia. However, each species displayed distinct phenotypic and genotypic features. For example, S. timoneanum PMMF0107 was able to assimilate more carbon sources than S. massiliense PMMF0073, such as adonitol, α-methyl-D-glucoside, trehalose, turanose, succinic acid mono-methyl ester, and alaninamide. The polyphasic approach, combining the results of complementary phenotypic and genomic assays, was instrumental for describing and characterising these two new Syncephalastrum species. [ABSTRACT FROM AUTHOR]

Mucormycosis is a progressive and life-threatening disease that has been increasingly reported in patients infected by coronavirus diseases 2019 (COVID-19). We describe a case of rhino-orbital mucormycosis with central nervous system involvement resulting in bilateral blindness and intracranial extension in a patient with uncontrolled diabetes mellitus (DM) and mild COVID-19 infection. A 35-year-old obese male, recently diagnosed with DM, presented to the emergency department suffering from dizziness, headache, speech difficulty, and facial weakness. His glycosylated hemoglobin was 10.4% and his reverse transcriptase-polymerase chain reaction (PCR) test came positive for COVID-19. Ocular examination revealed left eye proptosis, ophthalmoplegia, and lid edema with no ocular movement. Imaging studies showed pansinusitis and periorbital and orbital cellulitis with intracranial involvement. Histopathology and biopsy examination confirmed mucormycosis. Medical management included glucose control and liposomal amphotericin B therapy. Septoplasty and functional endoscopic sinus surgery was performed as emergency procedures. The patient survived with bilateral blindness. In this case, we described the importance of considering mucormycosis in COVID-19 patients with uncontrolled diabetes, particularly those presenting with sinusitis, headache, and orbital edema symptoms. Despite intensive antifungal therapy and surgical intervention, it is a serious opportunistic fungal infection associated with long-term complications. [ABSTRACT FROM AUTHOR]

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Mucorales are a group of non-septated filamentous fungi widely distributed in nature, frequently associated with human infections, and are intrinsically resistant to many antifungal drugs. For these reasons, there is an urgent need to improve the clinical management of mucormycosis. Miltefosine, which is a phospholipid analogue of alkylphosphocholine, has been considered a promising repurposing drug to be used to treat fungal infections. In the present study, miltefosine displayed antifungal activity against a variety of Mucorales species, and it was also active against biofilms formed by these fungi. Treatment with miltefosine revealed modifications of cell wall components, neutral lipids, mitochondrial membrane potential, cell morphology, and the induction of oxidative stress. Treated Mucorales cells also presented an increased susceptibility to SDS. Purified ergosterol and glucosylceramide added to the culture medium increased miltefosine MIC, suggesting its interaction with fungal lipids. These data contribute to elucidating the effect of a promising drug repurposed to act against some relevant fungal pathogens that significantly impact public health. [ABSTRACT FROM AUTHOR]

Objective: To detect the presence of Mucorales in the sinuses of healthy individuals and non-invasive fungal sinusitis patients. Materials and methods: Post FESS specimens with appearance suggestive of fungal ball or allergic mucin from 30 immunocompetent patients was sent for KOH smear, HPE, fungal culture and PCR. Results: Fungal culture was positive for Aspergillus flavus in one specimen. PCR demonstrated Aspergillus (21), Candida (14), and Rhizopus in one case. HPE detected mainly Aspergillus in 13 specimens. No fungal presence in four cases. Discussion: There was no significant undetected Mucor colonisation. PCR proved to be the most sensitive test in reliably detecting the organisms. No significant variation in the pattern of fungi were detected between COVID-19 infected and non-infected, but for the slightly higher detection of candida in the COVID-19 infected group. Conclusion: There was no significant presence of Mucorales in non-invasive fungal sinusitis patients in our study. [ABSTRACT FROM AUTHOR]

Mucormycosis is a lethal and difficult-to-treat fungal infection caused by fungi of the order Mucorales. Mucor lusitanicus, a member of Mucorales, is commonly used as a model to understand disease pathogenesis. However, transcriptional control of hyphal growth and virulence in Mucorales is poorly understood. This study aimed to investigate the role of Tec proteins, which belong to the TEA/ATTS transcription factor family, in the hyphal development and virulence of M. lusitanicus. Unlike in the genome of Ascomycetes and Basidiomycetes, which have a single Tec homologue, in the genome of Mucorales, two Tec homologues, Tec1 and Tec2, were found, except in that of Phycomyces blakesleeanus, with only one Tec homologue. tec1 and tec2 overexpression in M. lusitanicus increased mycelial growth, mitochondrial content and activity, expression of the rhizoferrin synthetase-encoding gene rfs, and virulence in nematodes and wax moth larvae but decreased cAMP levels and protein kinase A (PKA) activity. Furthermore, tec1- and tec2-overexpressing strains required adequate mitochondrial metabolism to promote the virulent phenotype. The heterotrimeric G beta subunit 1-encoding gene deletant strain (Δgpb1) increased cAMP-PKA activity, downregulation of both tec genes, decreased both virulence and hyphal development, but tec1 and tec2 overexpression restored these defects. Overexpression of allele-mutated variants of Tec1(S332A) and Tec2(S168A) in the putative phosphorylation sites for PKA increased both virulence and hyphal growth of Δgpb1. These findings suggest that Tec homologues promote mycelial development and virulence by enhancing mitochondrial metabolism and rhizoferrin accumulation, providing new information for the rational control of the virulent phenotype of M. lusitanicus. [ABSTRACT FROM AUTHOR]

Upper-extremity mucormycosis is a rare, life-threatening fungal infection mainly affecting immunocompromised patients. We report a case of a 30-year-old woman with acute myelogenous leukemia who developed this infection during her hospital stay. The culprit was Mucorales, a subgroup of Zygomycetes species known for fast-progressing, highly lethal infections. She presented with fever, chills, and a lesion on her left forearm that worsened despite initial broad-spectrum antibiotics. A punch biopsy confirmed the diagnosis, leading to antifungal therapy with isavuconazonium sulfate and later amphotericin B, combined with surgery. Timely intervention is critical because delayed treatment can result in severe complications and death. Early suspicion, histology, microscopy, and fungal cultures are vital for accurate diagnosis. Treatment primarily involves amphotericin B, whereas adjunctive therapies such as topical amphotericin B and hyperbaric oxygen show promise. This case underscores the importance of prompt medical and surgical action, enhancing early detection of mucormycosis in immunocompromised patients.

Introduction: Mucormycosis is an opportunistic fungal infection that became a public health emergency during the second wave of Coronavirus Disease-2019 (COVID-19). It is an acute, angioinvasive, opportunistic, and emerging mycosis caused by mucormycetes, resulting in a significantly fatal fungal infection among immunocompromised and/or immunosuppressed individuals. Mucormycosis has a specific predilection for blood vessels (angioinvasive) and tissues, leading to extensive necrosis and thromboembolic events. Globally, the incidence rate of mucormycosis varies from 0.005 to 1.7 per million people. Early diagnosis and appropriate therapy are crucial for clinical outcomes. Aim: To evaluate the mycological profile of mucormycosis during the COVID-19 pandemic using automated Matrix Assisted Laser Desorption Ionisation Time of Flight Mass Spectroscopy (MALDI-ToF-MS) in comparison with conventional fungal identification methods. Materials and Methods: A retrospective cohort study was conducted, collecting data from July 2020 to June 2022, involving 1,176 patients from various clinical departments who attended PSG Hospitals affiliated with PSG Institute of Medical Sciences and Research, Coimbatore, Tamil Nadu, India. Data analysis was performed from July 2022 to August 2022. Clinical specimens, including Bronchoalveolar Lavage (BAL), Sputum, Cerebrospinal Fluid (CSF), nasal swabs, tracheal aspirates, pus, blood, corneal scraping, eye discharge, and necrotised tissues, were subjected to Potassium Hydroxide (KOH) mount, conventional culture coupled with micrometry-aided microscopy, and MALDI-ToF-MS among suspected mucormycosis cases. The results were collected in Microsoft Excel, and data analysis was conducted using the International Business Machines Statistical Package for the Social Sciences statistical software (IBM SPSS) version 24.0. The study variables were expressed as descriptive statistics: frequency (N) and percentage (%). The incidence of mucormycosis, mycological profile, and diagnostic utility of conventional micrometry-aided microscopy-assisted culture were compared with the automated MALDI-ToF-MS protein signature method of testing. Results: Fungal elements were positive in 130 (11.05%) out of a total of 1,176 clinical samples, such as necrotised tissue, biopsy, and sputum, in the KOH mount. Fungal culture was positive in 258 (21.94%) out of 1176 samples, with mucormycosis detected in 73 (28.29%) of the culture-positive samples. The incidence of mucormycosis in this study was 73 (6.21%) out of 1176. A total of 101 (8.59%) samples showed positive results for mucormycetes through KOH, culture, and MALDI-ToF-MS. MALDI-ToF-MS could rapidly and specifically identify and confirm the causative agents of mucormycosis at their genus and species levels compared to KOH or culture. Conclusion: Simple, low-cost, and less laborious conventional culture coupled with micrometry-aided microscopy can detect Mucorales at the species level, where KOH microscopy could not differentiate between species. MALDI-ToF-MS can be employed for the rapid detection and confirmation of mucormycosis agents at the genus or species level.

A 54-year-old woman with fever and cough presented with left upper lobe consolidation and para-aortic and hilar lymphadenopathies and was diagnosed with sarcoidosis, and her condition improved spontaneously. Over the next 15 years, the patient experienced seven similar episodes and was treated with glucocorticoids for the first time in the eighth episode, but subsequently died of respiratory failure. The autopsy revealed diffuse alveolar damage and co-infection with Aspergillus fumigatus and Mucorales in the lungs and mediastinum. The clinical course and autopsy results suggest that glucocorticoids caused the growth of fungi already infected in the patient, and co-infection with the other.

ABSTRACTMucormycosis is classified by the National Institute of Allergy and Infectious Diseases as an emerging disease and is caused by Mucorales fungi. Despite the high morbidity and mortality rates associated with the disease, little is known about the host-pathogen interactions that dictate disease progression. The recent surge of mucormycosis cases among COVID-19 patients has thrust the disease and the lack of available treatments into the spotlight. Despite severe fungal angioinvasion and tissue necrosis during infection, clinical observations suggest a lack of pro-inflammatory responses. Understanding immune evasion mechanisms in mucormycosis can help guide potential therapeutic options. In this study, we demonstrate that Mucorales fungi can suppress the accumulation of nitric oxide (NO) in lipopolysaccharide- and interferon gamma-stimulated macrophages despite robust expression of the Nos2 mRNA and inducible nitric oxide synthase protein. This suppressive activity requires fungal viability and direct contact with macrophages and is not due to restricted access to L-arginine substrate. While Mucorales fungi appear to be able to remove NO from its environment, it does not account for the full suppression that we observe and suggests that Mucorales employs at least two mechanisms. Future experiments will elucidate the mechanisms by which Mucorales fungi deplete NO accumulation by macrophages and the implications of this depletion in mucormycosis pathogenesis.IMPORTANCEIn October 2022, Mucorales fungi were listed in the “High Priority Group” on the first-ever list of fungal priority pathogens by the World Health Organization. As the causative agent of mucormycosis, Mucorales have become of great clinical and public health importance with growing mucormycosis numbers, notably with the exponential rise of COVID-19-associated mucormycosis cases. Despite the dire need, there are limited therapeutic options to treat mucormycosis. Our research fills in critical gaps of knowledge about how Mucorales fungi evade the host immune system. Specifically, we offer evidence that Mucorales block nitric oxide production, which is a key mediator and signaling molecule of the mammalian innate immune response to microbial pathogens. Our work offers new insight into immune evasion mechanisms by Mucorales fungi.

ABSTRACT This study aimed to evaluate the epidemiology of fungi in environment of tertiary care hospitals and their susceptibility patterns to seven antifungal agents for controlling and preventing fungal infections in patients. Environmental samplings on the surfaces of different parts of hospitals were collected from four university-affiliated teaching hospitals in Iran. Routine and molecular procedures identified isolated fungi, and antifungal susceptibility tests were performed in vitro. Of the 400 samples, 152 presented positive culture results, and 193 fungal species were isolated. Mold fungi accounted for 59.1% (115 species) of isolates. Most isolated fungal species in descending order were 22 Aspergillus flavus (11.4%), 21 Candida albicans (10.9%), 17 Mucor species (8.8%), 16 Penicillium species (8.3%), 16 Candida famata (8.3%), 15 Alternaria species (7.8%), 13 Fusarium species (6.7%), 11 Candida parapsilosis (5.7%), and 10 Aspergillus niger sensu stricto (5.2%). The isolated Aspergillus species revealed relatively low susceptibility to itraconazole and posaconazole with MIC90 values of 8 µg/mL. The MIC90 values of amphotericin and luliconazole in Candida species were 0.5 and 0.064 µg/mL, respectively. In this study, different species of filamentous and yeast fungi with varying susceptibility to antifungal agents were reported from the environment of the studied hospitals. IMPORTANCE Saprophytic fungi can cause nosocomial infections in high-risk patients. These infections are related to high mortality and cost. In the current study, different species of filamentous fungi and yeast were isolated from the environment of the studied hospitals. Some species were resistant to antifungal drugs. We suggest that the future work concentrates on the relationship between the level/quantification of saprophytic contamination in the environment of hospitals and fungal infections in patients.

ABSTRACT This study aims to assess the usefulness of peripheral blood metagenomic next-generation sequencing (mNGS) in diagnosing invasive mucormycosis (IM). We conducted a retrospective analysis of clinical data from 73 patients with mucorales sequences detected by peripheral blood mNGS at the First Affiliated Hospital, Zhejiang University School of Medicine, between February 2021 and December 2022. We examined data on risk factors, clinical symptoms, imaging characteristics, pathogenic findings, clinical diagnoses, and treatment outcomes. Among the 73 patients with mucorales sequences detected by peripheral blood mNGS, 7 cases were confirmed, 12 were probable, 34 were possible, and 20 were false positives, based on the diagnostic criteria for IM. Among the 34 possible cases, patients exhibited risk factors, clinical symptoms, imaging features, and prognoses consistent with IM. In 7 out of the 12 probable cases, the same mucorale nucleic acid was found in peripheral blood mNGS samples collected at an average interval of 8.1 days. In the remaining 20 patients, mucorales nucleic acid was detected in peripheral blood mNGS, but they lacked risk factors or clinical features of mucorales infection and lacked other pathological evidence, leading to a judgment of false positive. The positive predictive value of peripheral blood mNGS for diagnosing invasive mucormycosis in the cases studied was 72.6%. Peripheral blood mNGS testing provides valuable insights for diagnosing invasive mucormycosis. However, it should be used in conjunction with risk factors, clinical features, and other pathogenic test results to make a comprehensive assessment. IMPORTANCE Given the high fatality rates, prompt and accurate identification of the fungal culprit is crucial, emphasizing the need for invasive mucormycosis. Unfortunately, mucormycosis lacks definitive biomarkers, depending primarily on smears, cultures, or pathology, all necessitating invasive specimen collection from the infection site. However, obtaining valid specimens early in critically ill patients poses substantial risks and challenges. Whether peripheral blood metagenomic next-generation sequencing (mNGS) can enhance early mucormycosis diagnosis, especially when direct specimen collection from the infection site is challenging, is warranted. This is a large-scale clinical study conducted to evaluate the utility and clinical impact of mNGS of peripheral blood for the diagnosis of invasive mucormycosis. We believe our study provided both novelty in translational medicine and a great value for the medical community to understand the strengths and limitations of mNGS of peripheral blood as a new diagnostic tool for the diagnosis and management of invasive mucormycosis.

Mucoromycosis is a highly aggressive angio-invasive disease of humans caused by fungi in the zygomycete order, Mucorales. While Rhizopus arrhizus is the principal agent of mucoromycosis, other Mucorales fungi including Apophysomyces, Cunninghamella, Lichtheimia, Mucor, Rhizomucor and Syncephalastrum are able to cause life-threatening rhino-orbital-cerebral, pulmonary, gastro-intestinal and necrotising cutaneous infections in humans. Diagnosis of the disease currently relies on non-specific CT, lengthy and insensitive culture from invasive biopsy, and time-consuming histopathology of tissue samples. At present, there are no rapid antigen tests that detect Mucorales-specific biomarkers of infection, and which allow point-of-care diagnosis of mucoromycosis. Here, we report the development of an IgG2b monoclonal antibody (mAb), TG11, which binds to extracellular polysaccharide (EPS) antigens of between 20 kDa and 250 kDa secreted during hyphal growth of Mucorales fungi. The mAb is Mucorales-specific and does not cross-react with other yeasts and molds of clinical importance including Aspergillus, Candida, Cryptococcus, Fusarium, Lomentospora and Scedosporium species. Using the mAb, we have developed a Competitive lateral-flow device that allows rapid (30 min) detection of the EPS biomarker in human serum and bronchoalveolar lavage (BAL), with a limit of detection (LOD) in human serum of ~100 ng/mL serum (~224.7 pmol/L serum). The LFD therefore provides a potential novel opportunity for detection of mucoromycosis caused by different Mucorales species.