Nitrogen-doped carbon quantum dots as a novel treatment for black fungal bone infections (Mucormycosis): in vitro and in vivo study

Most fungal bone and joint infections (arthritis) are caused by Mucormycosis (Mucor indicus). These infections may be difficult to treat and may lead to chronic bone disorders and disabilities, thus the use of new antifungal materials in bone disorders is vital, particularly in immunocompromised individuals, such as those who have contracted coronavirus disease 2019 (COVID-19). Herein, we reported for the first time the preparation of nitrogen-doped carbon quantum dots (N/CQDs) and a nitrogen-doped mesoporous carbon (N/MC) using a quick micro-wave preparation and hydrothermal approach. The structure and morphology were analysed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and surface area analyser. Minimum inhibitory concentration (MIC), disc diffusion tests, minimum fungicidal concentration (MFC) and antifungal inhibitory percentages were measured to investigate the antifungal activity of N/CQDs and N/MC nanostructures. In addition to the in vivo antifungal activity in rats as determined by wound induction and infection, pathogen count and histological studies were also performed. According to in vitro and in vivo testing, both N/CQDs with small size and N/MC with porous structure had a significant antifungal impact on a variety of bone-infecting bacteria, including Mucor infection. In conclusion, the present investigation demonstrates that functional N/CQDs and N/MC are effective antifungal agents against a range of microbial pathogenic bone disorders in immunocompromised individuals, with stronger and superior fungicidal activity for N/CQDs than N/MC in vitro and in vivo studies.

Molecular mechanisms that govern infection and antifungal resistance in Mucorales

SUMMARYThe World Health Organization has established a fungal priority pathogens list that includes species critical or highly important to human health. Among them is the order Mucorales, a fungal group comprising at least 39 species responsible for the life-threatening infection known as mucormycosis. Despite the continuous rise in cases and the poor prognosis due to innate resistance to most antifungal drugs used in the clinic, Mucorales has received limited attention, partly because of the difficulties in performing genetic manipulations. The COVID-19 pandemic has further escalated cases, with some patients experiencing the COVID-19-associated mucormycosis, highlighting the urgent need to increase knowledge about these fungi. This review addresses significant challenges in treating the disease, including delayed and poor diagnosis, the lack of accurate global incidence estimation, and the limited treatment options. Furthermore, it focuses on the most recent discoveries regarding the mechanisms and genes involved in the development of the disease, antifungal resistance, and the host defense response. Substantial advancements have been made in identifying key fungal genes responsible for invasion and tissue damage, host receptors exploited by the fungus to invade tissues, and mechanisms of antifungal resistance. This knowledge is expected to pave the way for the development of new antifungals to combat mucormycosis. In addition, we anticipate significant progress in characterizing Mucorales biology, particularly the mechanisms involved in pathogenesis and antifungal resistance, with the possibilities offered by CRISPR-Cas9 technology for genetic manipulation of the previously intractable Mucorales species.

Fourteen cases of acute invasive fungal rhinosinusitis: is there a place for less aggressive surgical treatment?

PURPOSE

Acute invasive fungal rhinosinusitis (AIFRS) is a rare, fulminant, angio-invasive infection with high mortality rate. Treatment of AIFRS includes aggressive surgical debridement combined with antifungal agents and treatment of the underlying disease. The aim of this study is to report our experience with this often fatal disease and estimate the long-term survival of AIFRS patients with more conservative surgery.

METHODS

A retrospective study was performed on immunocompromised adults with AIFRS from January 2011 to December 2020. The diagnosis was histologically confirmed by tissue fungus invasion. We analyze epidemiological and microbiological findings, the underlying disease and discuss our patients' treatment plan and long-term survival.

RESULTS

Fourteen patients were included in the study. Mean age was 53.8 ± 18.9 years. The underlying disease was hematologic malignancy in nine patients, diabetes mellitus in three, aplastic anemia in one, and renal/liver failure in one. Leukopenia was not significantly correlated with outcome or survival. Histological and culture findings revealed that Mucor/Rhizopus were the causative organisms in nine cases. All patients received systemic antifungal therapy. Surgery was performed in nine patients (endoscopic for all patients, combined in three with an external approach). Overall survival was 35.7% as five patients survived, two who underwent surgery, and three who were treated non-surgically. Nine patients died, two from AIFRS after central nervous system involvement and seven from their primary disease, free of fungi. Older individuals and patients with hematologic malignancies had a worse outcome.

CONCLUSION

Early surgical debridement, antifungal agents, and treatment of the underlying disease remain the cornerstones of AIFRS management. Prognosis is overall defined by the underlying disease and in some selected cases, medical treatment alone could be a reasonable option.

Mucorales fungi suppress nitric oxide production by macrophages

IMPORTANCE

In 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.

A Systematic Review of the Therapeutic Outcome of Mucormycosis

Background

Mucormycosis is a potentially lethal mycosis. We reviewed peer-reviewed publications on mucormycosis to assess therapeutic outcomes.

Methods

A systematic literature search using the Ovid MEDLINE and EMBASE databases identified manuscripts describing human mucormycosis diagnosed according to European Organization for Research and Treatment of Cancer and the Mycoses Study Group criteria with therapeutic outcomes published from 2000 to 2022.

Results

In 126 articles, 10 335 patients were described, most from Asia (n = 6632, 66%). Diabetes was the most frequent underlying disease (n = 6188, 60%); 222 (2.1%) patients had no underlying diseases. The dominant clinical form was rhino-orbitocerebral (n = 7159, 69.3%), followed by pulmonary (n = 1062, 10.3%). Of 5364 patients with outcome data, amphotericin B monotherapy (n = 3749, mortality 31.5%) was most frequent, followed by amphotericin B + azole (n = 843, mortality 6.6%; P < .0001), amphotericin B followed by azole (n = 357, mortality 13.7%; P < .0001), posaconazole only (n = 250, mortality 17.2%; P < .0001), and isavuconazole only (n = 65, mortality 24.6%; P = .24). Duration and dose of antifungals varied widely. Documented outcomes from surgical resections in 149 patients found that 47 of 125 died (37.6%), compared with 16 of 24 (66.7%) patients who did not undergo surgery (P = .008).

Conclusions

Mucormycosis is more frequently reported in Asia than in Europe and is often linked to diabetes. Antifungal therapy, usually with surgery, is frequently effective for mucormycosis.

A Novel Classification System for Oral Cavity Mucormycosis: a Hospital Based Cross-Sectional Study

Background

Rhino-oculo-cerebral Mucormycosis (ROCM) is a well-known complication post-COVID-19 infection. The extension of this disease into the oral cavity is a grey area with no proper protocol for management of the same in the existing literature. Based on our experience in the management of oral extension, this study aims to propose a protocol to treat these cases.

Aim

To derive a classification for the surgeon from retrospectively collected data of 53 operated cases of oral Mucormycosis.

Settings and Design

Hospital record-based cross-sectional study; evaluation of the previously treated 53 cases of oral extension of post-COVID-19 Rhino-oculo-cerebral Mucormycosis in the duration between May 2021 to August 2021. Follow-up for a period of 1 year.

Methods and Material

Based on the preoperative data, 4 parameters were taken -Tooth tenderness, Tooth mobility, Palatal perforation, and Radiological findings. A clinical-radiological classification system was derived based on the intraoperative data from the OT notes and the preoperative findings corresponding to the 4 parameters.

Statistical Analysis

The statistical analysis was done using SPSS for windows version 20 software (SPSS Inc., Chicago, IL, USA).

Results

Totally 220 cases of ROCM were recorded in our institute. Of this, 53 patients were treated for ROCM extending into the oral cavity. In 27 patients, we were able to achieve primary closure. In 26 patients, there was oro-antral communication after removal of the palate. Based on this data, we derived a protocol that may be used by the treating surgeon to manage oral cavity cases of ROCM, so that aggressive tissue resection may be avoided unnecessarily.

Conclusion

This protocol will help the treating surgeon to have a clearer outlook on treating this disease.

Cadavers found outdoor in whom fungal growth was observed on the body surface: Consideration of the role of mycology in forensic medicine

In forensic case work, fungal growth is occasionally observed on decomposed cadavers, however, the isolation of these organisms is not always carried out routinely. The usefulness of investigating fungi isolated from corpses in forensic settings, has been reported, such as providing trace evidence, estimating the time since death, and ascertaining the time of deposition. A 32-year-old male missing for 4 months, was found in a car in a forest far from his home and had died from blood loss, having been stabbed with a kitchen knife in the left side of his chest. Whitish or white greenish colonies ranging 5 cm to 8 cm in size were observed over his whole body. Penicillium commune and Cladosporium cladosporioides were isolated from the colonies. A 49-year-old male missing for one month, and was found dead at 500 m elevation in the mountains. An autopsy was conducted, but the cause of death could not be determined. Dark greenish or whitish colonies were found on his face and neck, and Epicoccum nigrum, Mucor sp.. Cladosporium sp., and Pestalotiopsis sp. were isolated. Penicillium sp. and Cladosporium sp. are major indoor fungi, and Epicoccum sp. and Pestalotiopsis sp. are plant pathogens found in outdoor environments. There was no discrepancy between the police statement and findings of the corpse such as place discovered, types of isolated fungi, and estimated time since death. Identifying fungi on cadavers may aid in forensic casework, and further studies are needed to develop for the use of fungi as a forensic tool.

Cold adapted and closely related mucoraceae species colonise dry-aged beef (DAB)

The dry ageing is a historically relevant method of meat preservation, now used as a way to produce the dry-aged beef (DAB) known for its pronounced flavour. Partially responsible for the taste of the DAB may be various microorganisms that grow on the surface of the meat. Historically, the fungal species colonising the DAB were described as members of the genera Thamnidium and Mucor. In this study we used both culture based approach as well as ITS2 rDNA metabarcoding analysis to investigate the fungal community of the DAB, with special emphasis on the mucoralean taxa. Isolated fungi were members of 6 different species from the family Mucoraceae, belonging to the genera Mucor and Helicostylum. Metabarcoding data provided supplementary information regarding the presence of other fungi including those from the Thamnidium genus. In both approaches used in this study isolates closely related to the Mucor flavus strain CBS 992.68 dominated.

Fungal spore swelling and germination are restricted by the macrophage phagolysosome

Many species of medically important fungi are prolific in the formation of asexual spores. Spores undergo a process of active swelling and cell wall remodelling before a germ tube is formed and filamentous growth ensues. Highly elongated germ tubes are known to be difficult to phagocytose and pose particular challenges for immune phagocytes. However, the significance of the earliest stages of spore germination during immune cell interactions has not been investigated and yet this is likely to be important for defence against sporogenous fungal pathogens. We show here that macrophages restrict the early phases of the spore germination process of Aspergillus fumigatus and Mucor circinelloides including the initial phase of spore swelling, spore germination and early polarised growth. Macrophages are therefore adept at retarding germination as well as subsequent vegetative growth which is likely to be critical for immune surveillance and protection against sporulating fungi.

Bronchoscopic instillation of amphotericin B is a safe and effective measure to treat pulmonary mycosis

Background and objectives: In recent years, there has been a significant increase in the prevalence of pulmonary mycosis disease, and its mortality has increased. There are very few studies on treating pulmonary mycosiss with bronchoscopic instillation of amphotericin B. This study investigated the clinical efficacy and safety of bronchoscopic instillation of amphotericin B for treating pulmonary mycosiss. Methods: This was a multi-centre, retrospective clinical study of 80 patients with pulmonary mycosiss who were treated with bronchoscopic instillation of amphotericin B. The efficacy and safety of this treatment were evaluated. Results: Eighty patients were included {51 males; mean [standard deviation (SD)] age, 46 (15.9) years}. The most common underlying cause was haematological malignancy (73.75%). The mean number of bronchoscopic instillations of amphotericin B was 2.4 (SD 1.5). In terms of treatment success, 58 (72.5%) patients achieved complete or partial changes on imaging after treatment. A total of 62 (77.5%) patients achieved complete or partial changes on imaging and/or local limitation of the mycosis infection. Seventy-six (95%) patients achieved complete or partial changes on imaging and/or local limitation of mycosis infection and/or an immunotherapy time window. The efficacy rates for treatment of Aspergillus and Mucor infections in terms of the three treatment success criteria described above were 73.81% vs. 63.64%, 80.95% vs. 72.73%, and 92.86% vs. 90.91%, respectively. Conclusion: Bronchoscopic instillation of amphotericin B is safe and effective for treatment of pulmonary mycosiss.

Probiotics and their postbiotics for the control of opportunistic fungal pathogens: A review

During past twenty years the opportunistic fungal infections have been emerging, causing morbidity and mortality. The fungi belonging to Aspergillus, Mucor, Rhizopus, Candida, Fusarium, Penicillium, Dermatophytes and others cause severe opportunistic fungal infections. Among these Aspergillus and Candida spp cause majority of the diseases. The continuum of fungal infections will prolong to progress in the surroundings of the growing inhabitants of immunocompromised individuals. Presently many chemical-based drugs were used as prophylactic and therapeutic agents. Prolonged usage of antibiotics may lead to some severe effect on the human health. Also, one of the major threats is that the fungal pathogens are becoming the drug resistant. There are many physical, chemical, and mechanical methods to prevent the contamination or to control the disease. Owing to the limitations that are observed in such methods, biological methods are gaining more interest because of the use of natural products which have comparatively less side effects and environment friendly. In recent years, research on the possible use of natural products such as probiotics for clinical use is gaining importance. Probiotics, one of the well studied biological products, are safe upon consumption and are explored to treat various fungal infections. The antifungal potency of major groups of probiotic cultures such as Lactobacillus spp, Leuconostoc spp, Saccharomyces etc. and their metabolic byproducts which act as postbiotics like organic acids, short chain fatty acids, bacteriocin like metabolites, Hydrogen peroxide, cyclic dipeptides etc. to inhibit these opportunistic fungal pathogens have been discussed here.

Novel Approaches in the Management of Mucormycosis

Purpose of Review

Invasive mucormycosis (IM), caused by fungi of the order Mucorales, is one of the deadliest fungal infection among hematologic cancer patients. Its incidence is also increasingly reported in immunocompetent individuals, notably with the COVID-19 pandemic. Therefore, there is an urgent need for novel diagnostic and therapeutic approaches of IM. This review discusses the current advances in this field.

Recent Findings

Early diagnosis of IM is crucial and can be improved by Mucorales-specific PCR and development of lateral-flow immunoassays for specific antigen detection. The spore coat proteins (CotH) are essential for virulence of the Mucorales and may represent a target for novel antifungal therapies. Adjuvant therapies boosting the immune response, such as interferon-γ, anti-PDR1 or fungal-specific chimeric antigen receptor (CAR) T-cells, are also considered.

Summary

The most promising perspectives for improved management of IM consist of a multilayered approach targeting both the pathogen and the host immune system.

Serine/Threonine Phosphatase Calcineurin Orchestrates the Intrinsic Resistance to Micafungin in the Human-Pathogenic Fungus Mucor circinelloides

Procedures such as solid-organ transplants and cancer treatments can leave many patients in an immunocompromised state. This leads to their increased susceptibility to opportunistic diseases such as fungal infections. Mucormycosis infections are continually emerging and pose a serious threat to immunocompromised patients. Recently there has been a sharp increase in mucormycosis cases as a secondary infection in patients battling severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Mucorales fungi are notorious for presenting resistance to most antifungal drugs. The absence of effective means to treat these infections results in mortality rates approaching 100% in cases of disseminated infection. One of the most effective antifungal drug classes currently available is the echinocandins. Echinocandins seem to be efficacious in the treatment of many other fungal infections. Unfortunately, susceptibility testing has found that echinocandins have little to no effect on Mucorales fungi. In this study, we found that the model Mucorales Mucor circinelloides genome carries three copies of the genes encoding the echinocandin target protein β-(1,3)-d-glucan synthase (fksA, fksB, and fksC). Interestingly, we found that exposing M. circinelloides to micafungin significantly increased the expression of the fksA and fksB genes, resulting in an increased accumulation of β-(1,3)-d-glucan on the cell walls. However, this overexpression of the fks genes is not directly connected to the intrinsic resistance. Subsequent investigation discovered that the serine/threonine phosphatase calcineurin regulates the expression of fksA and fksB, and the deletion of calcineurin results in a decrease in expression of all three fks genes. Deletion of calcineurin also results in a lower minimum effective concentration (MEC) of micafungin. In addition, we found that duplication of the fks gene is also responsible for the intrinsic resistance, in which lack of either fksA or fksB led a lower MEC of micafungin. Together, these findings demonstrate that calcineurin and fks gene duplication contribute to the intrinsic resistance to micafungin we observe in M. circinelloides.

Disseminated Invasive Mucormycosis Infection Following Autologous Stem Cell Transplantation for Diffuse Large B-Cell Lymphoma

Invasive fungal infections (IFI) are challenging to predict, diagnose and treat, and are associated with a particularly high mortality among patients with hematological malignancies. They are relatively uncommon in patients with lymphoma, compared with those with acute leukemia or undergoing allogeneic transplantation. We present a patient, autografted for recurrent lymphoma, with fever and refractory diarrhea persisting post engraftment, eventually attributable to disseminated mucor infection. This case illustrates the challenge of timely diagnosis and initiation of treatment for IFI in lymphoma patients, who do not routinely receive antifungal prophylaxis, and the importance of aggressive investigation and symptom-directed tissue sampling for evidence of IFI in febrile immunocompromised hosts not responding to broad-spectrum antibiotics.

Complement, but Not Platelets, Plays a Pivotal Role in the Outcome of Mucormycosis In Vivo

BACKGROUND

Mucormycetes, a heterogeneous group of fungi, induce a life-threatening disease called mucormycosis. Immune deficiencies represent a major risk factor; hence, we wanted to illuminate the role of complement and platelets in the defense against mucormycetes.

METHODS

Rhizopus arrhizus (Ra), Rhizopus microsporus (Rm), Lichtheimia ramosa (Lr), Lichtheimia corymbifera (Lc), Rhizomucor pusillus (Rmp), and Mucor circinelloides (Mc) spores were opsonized with human and mouse serum, and C1q, C3c, and terminal complement complex (C5b-9) deposition was measured. Additionally, thrombocytopenic, C3-deficient, or C6-deficient mice were intravenously infected with selected isolates. Survival and immunological parameters were monitored, and fungal burden was determined and compared to that of immunocompetent and neutropenic mice.

RESULTS

In vitro experiments showed significant differences in complement deposition between mucormycetes. Mc isolates bound up to threefold more human C5b-9 than other mucormycetes. Lr, Lc, and Mc bound high levels of murine C3c, whereas human C3c deposition was reduced on Mc compared to Lr and Lc. Murine C3c deposition negatively correlated with virulence. Complement deficiencies and neutropenia, but not thrombocytopenia, were shown to be a risk factor for a lethal outcome.

CONCLUSION

Complement deposition varies between mucormycetes. Additionally, we demonstrated that complement and neutrophilic granulocytes, but not platelets, play an important role in a murine model of disseminated mucormycosis.

Mouse Models of Mucormycosis

Animal models have been crucial in understanding the pathogenesis and developing novel therapeutic approaches for fungal infections in general. This is especially true for mucormycosis, which has a low incidence but is often fatal or debilitating. Mucormycoses are caused by different species, via different routes of infections, and in patients differing in their underlying diseases and risk factors. Consequently, clinically relevant animal models use different types of immunosuppression and infection routes.This chapter describes how to induce different types of immunosuppression (high dose corticosteroids and induction of leukopenia, respectively) or diabetic ketoacidosis as underlying risk factors for mucormycosis. Furthermore, it provides details on how to perform intranasal application to establish pulmonary infection. Finally, some clinical parameters that can be used for developing scoring systems and define humane endpoints in mice are discussed.

High Prevalence of Fungal and NDM-OXA Producing Gram-Negative Bacterial Superinfections in the Second Wave of Coronavirus Disease 2019 in India: Experience from a Dedicated Coronavirus Disease 2019 Hospital in North India

Introduction

During the second wave of coronavirus disease 2019 (COVID-19), superinfection caused by fungus and multidrug-resistant bacteria worsened the severity of illness in COVID-19 patients. Limited studies from India reported the antimicrobial resistance pattern of secondary infections. In this study, we aim to study the epidemiology of pathogens causing superinfections and genotyping of Gram-negative isolates in COVID-19 patients.

Methods

This retrospective study was conducted at a dedicated COVID-19 center, India. The identification of bacteria/fungi was done by Vitek2^® and matrix-assisted laser desorption/ionization-time of flight mass spectrometry system. Identification of beta-lactamase genes was done using thermal cycler. The diagnosis of mucormycosis was based on 10% potassium hydroxide direct microscopy. Statistical analyses were performed using STATA version 15.1 (StataCorp., College Station, TX, USA). For continuous variables, mean and standard deviation were computed. For comparing proportions of secondary infections across admission location and outcomes, the Chi-squared test of independence was used. To compare the mean and median between intensive care units and outcomes, an independent t-test and a Mann-Whitney test were used.

Results

Of all the clinical samples, 45.4% of samples were cultured positive for secondary infections. Acinetobacter baumannii (35%) was the most common Gram-negative pathogen, while among Gram positive, it was Enterococcus faecium (40%). Among fungus, Candida spp. (61%) predominates followed by molds. Colistin and tigecycline proved effective against these pathogens. bla_NDM was the most prevalent gene followed by the bla_OX among the carbapenemase genes.

Conclusions

The mortality rate among COVID-19 patients with secondary infection was significantly higher compared to the overall mortality rate in COVID-19 patients.

Isolated laryngeal Mucormycosis requiring laryngectomy

We report a case of isolated laryngeal mucormycosis in a patient who presented in diabetic ketoacidosis (DKA). The patient was managed with antifungal therapy and eventual total laryngectomy. To our knowledge, this is the first case presented of mucormycosis with isolated laryngeal involvement.

Acute invasive mucormycosis rhinosinusitis causing multigroup cranial nerve injury and meningitis-A case report

This study reported a case of a Rhino-Orbital-Cerebral Mycosis (ROCM) patient with multiple groups of cranial nerve damage as the primary clinical manifestation, confirmed by histopathology and cerebrospinal fluid metagenomic next-generation sequencing (mNGS) technology. Relying on the MRI3D-SPACE technology, we observed the location and extent of the cranial nerve damage in the patient. The results suggested that fungal meningoencephalitis caused by mucor may enter the skull retrograde along the cranial nerve perineurium. The patient was admitted to the hospital with a preliminary diagnosis of mucormycosis infection after 1.5 days of mouth deviation. We treated the patient immediately with intravenous amphotericin B liposomes. After 21 days of hospitalization, the clinical symptoms of the patient did not improve significantly. The patient was discharged due to financial difficulties and antifungal treatment at home, and his disease had stabilized at the 6-month follow-up.

An atypical case report of extensive mucormycotic osteomyelitis of maxilla as a consequence of post-COVID complication

Saprophytic molds such as Mucor, Rhizopus, and Absidia cause mucormycosis, a fungal infection. These saprophytic fungi are common in the environment and have a strong proclivity for invading major blood arteries, causing tissue ischemia, necrosis, and infarction. They have been linked to immunocompromised individuals with a history of diabetic ketoacidosis, corticosteroid medication, HIV infection, malignant lymphomas, and patients currently receiving and recovering from COVID-19 treatment. The foregoing is the case of a 78-year-old COVID-19 recovered male who presented with a primary complaint of upper tooth movement for 1 month and maxillary segmental mobility. The maxillary alveolar process was resected, and histopathological reports revealed mucormycosis, which was treated with antifungal medication and nasolabial flap surgery. For the past 6 months, he has been disease-free. Early detection and treatment may offer a higher chance of successfully minimizing this debilitating condition.

Association of mold levels in urban children's homes with difficult-to-control asthma

BACKGROUND

Mold sensitization and exposure are associated with asthma severity, but the specific species that contribute to difficult-to-control (DTC) asthma are unknown.

OBJECTIVE

We sought to determine the association between overall and specific mold levels in the homes of urban children and DTC asthma.

METHODS

The Asthma Phenotypes in the Inner-City study recruited participants, aged 6 to 17 years, from 8 US cities and classified each participant as having either DTC asthma or easy-to-control (ETC) asthma on the basis of treatment step level. Dust samples had been collected in each participant's home (n = 485), and any dust remaining (n = 265 samples), after other analyses, was frozen at -20^oC. The dust samples (n = 265) were analyzed using quantitative PCR to determine the concentrations of the 36 molds in the Environmental Relative Moldiness Index. Logistic regression was performed to discriminate specific mold content of dust from homes of children with DTC versus ETC asthma.

RESULTS

Frozen-dust samples were available from 54% of homes of children with DTC (139 of 253) and ETC asthma (126 of 232). Only the average concentration of the mold Mucor was significantly (P < .001) greater in homes of children with DTC asthma. In homes with window air-conditioning units, the Mucor concentration contributed about a 22% increase (1.6 odds ratio; 95% CI, 1.2-2.2) in the ability to discriminate between cases of DTC and ETC asthma.

CONCLUSIONS

Mucor levels in the homes of urban youth were a predictor of DTC asthma, and these higher Mucor levels were more likely in homes with a window air-conditioner.

Mucormycosis: A comparative update between conventional and molecular diagnosis strategies

Mucormycosis is an opportunistic, aggressive, and angioinvasive fungal infection associated with a high mortality rate as it disseminates and infects the whole body if not treated early. Most conventional diagnostic methods require time and may also generate false-negative reports due to the several lacunae associated. On the other hand, molecular methods are rapid, reliable, and can be applied to different biological samples, such as fresh tissue, formalin-fixed paraffin-embedded blocks, serum, and urine. Mucorales are angio-invasive, and many studies have found the circulating fungal DNA (a non-invasive form of DNA) in the blood and urine of the patient. In addition, with the increase in the usage of steroid drugs in this COVID scenario, the rate of mucormycosis infection has taken a sudden rise. In light of this situation, there is an imperative need to diagnose these infections at the earliest.

Resolving the equation between mucormycosis and COVID-19 disease

The COVID-19 patients, both infected and recovered are rapidly contracting mucormycetes infections due to the 'Mucorales' order, under Zygomycetes class of fungi. The mucorales fungi commonly known to exist in our natural surroundings including soil, but the frequency of incidences was never rampant. This sudden spike in infections, is locally known as 'black fungus,' and is affecting various organs, including- eyes, sinuses, nose, brain, skin, intestine, lungs, etc. The severity of situation is ascertainable from the fact that, in certain cases surgical eye/jaws removal persists as the only viable option to avert mortality, as therapeutic interventions are limited. This epidemic situation intrigued experts to investigate the probable reason behind this unpredicted escalation in reported cases, including in recuperated COVID-19 patients, as person-to-person spread of infection is not common. The comparison of physiological parameters in healthy and COVID-19 afflicted patients highlights that the underlying conditions including diabetes mellitus, steroidal therapy, lymphopenia (decreased CD4+ and CD8+ lymphocytes), deregulated cytokine release storm, elevated free iron levels (hemosiderosis) in blood and insulin insensitivity are playing major roles in deteriorating conditions in rarely pathogenic fungal infections. This review is an attempt to explain the rationalities that makes people vulnerable to mucormycetes infection.

Image challenge: A diabetic man with facial swelling following recent Covid-19 infection

A 68-year-old man with diabetes presented with shortness of breath, left sided facial swelling, and nasal discharge. He had recently returned from India and PCR was positive for SARS-CoV-2 Delta variant. CT head and diffusion-weighted MRI sinuses were performed and the patient underwent endoscopic sinus surgery before being transferred to a specialist skull base centre.

COVID-19-associated mucormycosis: Case report and systematic review

BACKGROUND

Increasing number of patients with COVID-19-associated mucormycosis have been reported, especially from India recently. We have described a patient with COVID-19-associated mucormycosis and, searched and analyzed current medical literature to delineate the characteristics of COVID-19-associated mucormycosis.

METHOD

We reported a patient developed mucormycosis during post-COVID period. We searched literature to describe the incidence, clinical features, and outcomes of COVID-19-associated mucormycosis. Demographic features, risk factors, clinical features, diagnostic methods, treatment and outcome were analyzed.

RESULTS

We describe a 54-year-old male, hospitalized due to severe COVID-19 pneumonia. He was given long-term, high doses of systemic steroids. He developed maxillo-fascial mucormycosis and died of sepsis. Our literature search found 30 publications describing 100 patients including present case report. The majority (n = 68) were reported from India. 76% were male. The most commonly seen risk factors were corticosteroid use (90.5%), diabetes (79%), and hypertension (34%). Also, excessive use of broad-spectrum antibiotics were noted in cases. Most frequent involvements were rhino-orbital (50%), followed by rhino-sinusal (17%), and rhino-orbito-cerebral (15%). Death was reported as 33 out of 99 patients (33,3%).

CONCLUSIONS

Steroid use, diabetes, environmental conditions, excessive use of antibiotics, and hypoxia are main risk factors. Despite medical and surgical treatment, mortality rate is high. A multidisciplinary approach is essential to improve the conditions facilitating the emergence of COVID-19-associated mucormycosis.

Innovative intra-operative rapid detection test for visualisation of mucor

In this manuscript, we report a rapid intra-operative detection test for visualisation of mucor, with the use of the Smartphone-based intraocular lens microscope (IOLSCOPE). IOLSCOPE helps not only in detecting tissue affected by mucor, but also makes sure that the surgeon does not leave any fungus behind; similar to the principles employed by a ‘Frozen section’ in conventional general surgery. In the technique proposed by us, we have used an undigested tissue sample, to quickly diagnose mucor, intra-operatively. Thus, in view of tackling the COVID-19 and mucor duplet, IOLSCOPE can be considered by ophthalmologists and otorhinolaryngologists for its rapid screening property, convenience of ease, good quality images and cost effectiveness.

The core seed mycobiome of Pseudotsuga menziesii var. menziesii across provenances of the Pacific Northwest, USA

Fungal symbionts occur in all plant tissues, and many aid their host plants with critical functions, including nutrient acquisition, defense against pathogens, and tolerance of abiotic stress. "Core" taxa in the plant mycobiome, defined as fungi present across individuals, populations, or time, may be particularly crucial to plant survival during the challenging seedling stage. However, studies on core seed fungi are limited to individual sampling sites, raising the question of whether core taxa exist across large geographic scales. We addressed this question using both culture-based and culture-free techniques to identify the fungi found in individual seeds collected from nine provenances across the range of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii), a foundation tree species in the Pacific Northwest and a globally important timber crop that is propagated commercially by seed. Two key findings emerged: (i) Seed mycobiome composition differed among seed provenances. (ii) Despite variation in the seed mycobiome, we detected four core members, none of which is a known pathogen of Douglas-fir: Trichoderma spp., Hormonema macrosporum, Mucor plumbeus, and Talaromyces rugulosus. Our results support the concept of a core seed microbiome, yet additional work is needed to determine the functional consequences of core taxa for seedling germination, growth, survival, and competition.

DNA Methylation on N6-Adenine Regulates the Hyphal Development during Dimorphism in the Early-Diverging Fungus Mucor lusitanicus

The epigenetic modifications control the pathogenicity of human pathogenic fungi, which have been poorly studied in Mucorales, causative agents of mucormycosis. This order belongs to a group referred to as early-diverging fungi that are characterized by high levels of N6-methyldeoxy adenine (6mA) in their genome with dense 6mA clusters associated with actively expressed genes. AlkB enzymes can act as demethylases of 6mA in DNA, with the most remarkable eukaryotic examples being mammalian ALKBH1 and Caenorhabditis elegans NMAD-1. The Mucor lusitanicus (formerly M. circinelloides f. lusitanicus) genome contains one gene, dmt1, and two genes, dmt2 and dmt3, encoding proteins similar to C. elegans NMAD-1 and ALKBH1, respectively. The function of these three genes was analyzed by the generation of single and double deletion mutants for each gene. Multiple processes were studied in the mutants, but defects were only found in single and double deletion mutants for dmt1. In contrast to the wild-type strain, dmt1 mutants showed an increase in 6mA levels during the dimorphic transition, suggesting that 6mA is associated with dimorphism in M. lusitanicus. Furthermore, the spores of dmt1 mutants challenged with macrophages underwent a reduction in polar growth, suggesting that 6mA also has a role during the spore–macrophage interaction that could be important in the infection process.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

COVID-19-associated rhino-orbital- cerebral mixed mycoses with intracranial fungal granuloma - An aggressively managed rare entity

Rhino-orbital-cerebral mucormycosis (ROCM) with intracranial extension is a fatal disease. A case of extensive ROCM, with rare intracranial fungal granuloma, seen in a COVID-19 positive young male is described. A successful therapy consisting of a multidisciplinary approach for sinuses debridement, orbital exenteration, and intracranial granuloma excision was done. Nonseptate hyphae of Mucor and septate filamentous Aspergillus grew concurrently from exenterated orbital specimen.

Impact of the physiological state of fungal spores on their inactivation by active chlorine and hydrogen peroxide

This study aimed at assessing the impact of the physiological state of fungal spores on inactivation by sodium hypochlorite, 0.1% and 0.2% active chlorine, and 3% hydrogen peroxide. In this context, two physiological states were compared for 4 fungal species (5 strains). The first physiological state corresponded to fungal spores produced at 0.99 a_w and harvested using an aqueous solution (laboratory conditions), while the second one corresponded to fungal spores produced under a moderate water stress (0.95 a_w) and dry-harvested (mechanical harvesting without use of any water, mimicking food plant conditions). Aspergillus flavus "food plant" conidia were more resistant to all tested fungicide molecules than the "laboratory" ones. The same phenomenon was observed for Penicillium commune UBOCC-A-116003 conidia treated with hydrogen peroxide. However, this isolate did not exhibit any inactivation difference between "laboratory" and "food plant" conidia treated with sodium hypochlorite. Similarly, the physiological state of Cladosporium cladosporioides conidia did not impact the efficacy of the tested biocides. P. commune UBOCC-A-112059 "food plant" and "laboratory" conidia were more resistant to hydrogen peroxide and sodium hypochlorite, respectively. As for Mucor circinelloides, "laboratory" spores were more resistant to all disinfectant than the "food plant" ones. Noteworthy, regardless of the physiological state, all M. circinelloides and C. cladosporioides conidia were inactivated for 5 min treatment at 0.2% active chlorine and for 2.5 min treatment at 0.1% active chlorine, while the conidia of all the other species remained viable for these treatments. The obtained data indicate that the efficacy of disinfectant molecules depends not only on the encountered fungal species and its intraspecific diversity but also on the spore physiological state.

Epidemiology and Antifungal Susceptibilities of Mucoralean Fungi in Clinical Samples from the United States

The global incidence of mucormycosis has increased in recent years owing to higher numbers of individuals at risk for these infections. The diagnosis and treatment of this aggressive fungal infection are of clinical concern due to differences in species distribution in different geographic areas and susceptibility profiles between different species that are capable of causing highly aggressive infections. The purpose of this study was to evaluate the epidemiology and susceptibility profiles of Mucorales isolates in the United States over a 52-month period. Species identification was performed by combined phenotypic characteristics and DNA sequence analysis, and antifungal susceptibility testing was performed by CLSI M38 broth microdilution for amphotericin B, isavuconazole, itraconazole, and posaconazole. During this time frame, 854 isolates were included, representing 11 different genera and over 26 species, of which Rhizopus (58.6%) was the predominant genus, followed by Mucor (19.6%). The majority of isolates were cultured from the upper and lower respiratory tracts (55%). Amphotericin B demonstrated the most potent in vitro activity, with geometric mean (GM) MICs of ≤0.25 μg/ml against all genera with the exception of Cunninghamella species (GM MIC of 1.30 μg/ml). In head-to-head comparisons, the most active azole was posaconazole, followed by isavuconazole. Differences in azole and amphotericin B susceptibility patterns were observed between the genera with the greatest variability observed with isavuconazole. Awareness of the epidemiology of Mucorales isolates and differences in antifungal susceptibility patterns in the United States may aide clinicians in choosing antifungal treatment regimens. Further studies are warranted to correlate these findings with clinical outcomes.

Mucormycosis-induced upper gastrointestinal ulcer perforation in immunocompetent patients: a report of two cases

Background

Gastrointestinal mucormycosis (GIM) is a rare, opportunistic fungal infection with poor prognosis. Clinically, it is difficult to diagnose GIM owing to its nonspecific clinical symptoms and poor suspicion. The estimated incidence of GIM is inaccurate, and most cases are diagnosed accidentally during surgery or upon postmortem examination. GIM usually occurs in patients with immune deficiencies or diabetes. Here, we report two cases of immunocompetent young patients with GIM who had good prognosis after treatment. Compared to other case reports on GIM, our cases had unusual infection sites and no obvious predisposing factors, which make it important to highlight these cases.

Case presentation

The first case was that of a 16-year-old immunocompetent boy who was admitted with gastrointestinal bleeding and perforation due to a gastric ulcer. Strategies used to arrest bleeding during emergency gastroscopy were unsuccessful. An adhesive mass was then discovered through laparoscopy. The patient underwent type II gastric resection. Pathological examination of the mass revealed bacterial infection and GIM. The second case was of a 33-year-old immunocompetent woman with a recent history of a lower leg sprain. The patient subsequently became critically ill and required ventilatory support. After hemodynamic stabilization and extubation, she presented with hematemesis due to exfoliation and necrosis of the stomach wall. The patient underwent total gastrectomy plus jejunostomy. The pathology results revealed severe bacterial infection and fungal infection that was confirmed as GIM. The patient fully recovered after receiving anti-infective and antifungal treatments.

Conclusions

Neither patient was immunosuppressed, and both patients presented with gastrointestinal bleeding. GIM was confirmed via pathological examination. GIM is not limited to immunocompromised patients, and its diagnosis mainly relies on pathological examination. Early diagnosis, timely surgical treatment, and early administration of systemic drug treatment are fundamental to improving its prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01881-8.

Invasive Fungal Rhinosinusitis with and without Orbital Complications: Clinical and Laboratory Differences

Background: Invasive fungal rhinosinusitis (IFS) is a rare but often fatal disease. There are limited studies regarding IFS with orbital complications (IFSwOC). The present study aimed to identify the clinical signs associated with IFSwOC and prognosticators of the disease. Methods: A retrospective case series was conducted of patients histopathologically confirmed IFS or fungal rhinosinusitis with clinically apparent neuro-orbital complications who underwent surgery between 2008 and 2018. Demographic data, presenting symptoms and signs, culture data, laboratory results, and patient outcomes were obtained from medical records. Results: A total of 38 patients were identified, including 9 patients with IFSwOC, and 29 patients with IFS without orbital complications (IFSsOC). The clinical signs associated with developing orbital complications include headache, fever, sphenoid sinus, or posterior ethmoid sinus involvement, CRP level ≥ 1.025 mg/dL, or ESR level ≥ 46.5 mm/h. In IFSwOC group, male, posterior ethmoid sinus involvement, WBC count ≥ 9000 μL, CRP level ≥ 6.91 mg/dL, or ESR level ≥ 69 mm/h were correlated with a significantly poorer prognosis. Conclusion: IFS patients with sphenoid or posterior ethmoid sinus involvement, headache or fever as presenting symptoms, elevated CRP, and ESR level were at risk of developing orbital complications. Timely surgical debridement followed by systemic antifungal treatment may improve treatment outcomes.

[Mucormycosis: Current and future management perspective]

Infections caused by mucorales, with an increasing incidence after candidiasis and aspergillosis, are characterized by the fast angioinvasion of blood vessels and invasion of neighboring organs or structures. Mucorales most commonly cause rhinocerebral, pulmonary, cutaneous, digestive or disseminated infections, and their spread is favored by certain underlying diseases (diabetes, kidney failure) and risk factors (neutropenia, immunosuppression, iron overload). These infections have a high mortality rate, over 40% in many series, and the key to their cure depends on both an early diagnosis and an antifungal treatment, associated in most cases with extensive surgical debridement and other adjunctive therapies. Currently, there are international guidelines, not only local ones, for the management of mucormycosis, in which it is considered by consensus and with a strong recommendation that first-line treatment with high-dose liposomal amphotericin B is the best choice. The combined antifungal treatment of polyene agents with triazoles or candins remains in open debate.

Bioconversion of antifungal viridin to phytotoxin viridiol by environmental non-viridin producing microorganisms

Biotransformation of viridin, an antifungal produced by biocontrol agent, with non-viridin producing microorganisms is studied. The results show that some environmental non-targeted microorganisms are able to reduce it in the known phytotoxin viridiol, and its 3-epimer. Consequently, this reduction, which happens in some cases by detoxification mechanism, could be disastrous for the plant in a biocontrol of plant disease. However, a process fermentation/biotransformation could be an efficient approach for the preparation of this phytotoxin.

Evaluation of Sex Differences in Murine Diabetic Ketoacidosis and Neutropenic Models of Invasive Mucormycosis

There is increased concern that the quality, generalizability and reproducibility of biomedical research can be influenced by the sex of animals used. We studied the differences between male and female mice in response to invasive pulmonary mucormycosis including susceptibility to infection, host immune reaction and responses to antifungal therapy. We used diabetic ketoacidotic (DKA) or neutropenic mice infected with either Rhizopus delemar or Mucor circinelloides. The only difference detected was that when DKA mice were infected with M. circinelloides, female mice were more resistant to infection than male mice (median survival time of 5 vs. 2 days for female and male mice, respectively). However, a 100% lethality was detected among infected animals of both sexes. Treatment with either liposomal amphotericin B (L-AMB) or posaconazole (POSA) protected mice from infection and eliminated the difference seen between infected but untreated female and male mice. Treatment with L-AMB consistently outperformed POSA in prolonging survival and reducing tissue fungal burden of DKA and neutropenic mice infected with R. delemar or M. circinelloides, in both mouse sexes. While little difference was detected in cytokine levels among both sexes, mucormycosis infection in the DKA mouse model induced more inflammatory cytokines/chemokines involved in neutrophil (CXCL1) and macrophage (CXCL2) recruitment vs. uninfected mice. As expected, this inflammatory response was reduced in the neutropenic mouse model. Our studies show that there are few differences between female and male DKA or neutropenic mice infected with mucormycosis with no effect on the outcome of treatment or host immune response.

Characterization of Three Pleiotropic Drug Resistance Transporter Genes and Their Participation in the Azole Resistance of Mucor circinelloides

Mucormycosis is a life-threatening opportunistic infection caused by certain members of the fungal order Mucorales. This infection is associated with high mortality rate, which can reach nearly 100% depending on the underlying condition of the patient. Treatment of mucormycosis is challenging because these fungi are intrinsically resistant to most of the routinely used antifungal agents, such as most of the azoles. One possible mechanism of azole resistance is the drug efflux catalyzed by members of the ATP binding cassette (ABC) transporter superfamily. The pleiotropic drug resistance (PDR) transporter subfamily of ABC transporters is the most closely associated to drug resistance. The genome of Mucor circinelloides encodes eight putative PDR-type transporters. In this study, transcription of the eight pdr genes has been analyzed after azole treatment. Only the pdr1 showed increased transcript level in response to all tested azoles. Deletion of this gene caused increased susceptibility to posaconazole, ravuconazole and isavuconazole and altered growth ability of the mutant. In the pdr1 deletion mutant, transcript level of pdr2 and pdr6 significantly increased. Deletion of pdr2 and pdr6 was also done to create single and double knock out mutants for the three genes. After deletion of pdr2 and pdr6, growth ability of the mutant strains decreased, while deletion of pdr2 resulted in increased sensitivity against posaconazole, ravuconazole and isavuconazole. Our result suggests that the regulation of the eight pdr genes is interconnected and pdr1 and pdr2 participates in the resistance of the fungus to posaconazole, ravuconazole and isavuconazole.

Molecular identification of pathogenic fungi in formalin-fixed and paraffin-embedded tissues

Introduction. Histopathological examination (HPE) of tissue helps in the diagnosis of invasive fungal infections (IFIs) but cannot identify the fungus to the genus/species levelGap Statement Available protocols for the molecular identification of fungi from formalin-fixed and paraffin-embedded (FFPE) tissues have limitations in terms of extraction and target selection, and standardisation.Aim. Development of sequence-based fungal identification protocol after extraction of DNA from formalin-fixed and paraffin-embedded (FFPE) tissues.Methodology. A total of 63 FFPE tissues from histopathology proven IFI cases were used to standardize the DNA extraction (commercial QIAamp kit-based extraction and conventional phenol-chloroform-isoamyl alcohol [PCI] method) and sequence-based fungal identification protocols. The PCR targeted different ribosomal DNA (rDNA) regions including complete internal transcribed spacer (ITS1-5.8S-ITS2), separate ITS1 and ITS2, 18S and D1/D2 of 28S regions. Semi-nested PCR targeting Mucorales-specific 18S rDNA region was performed in tissues having aseptate hyphae. The optimized ITS1-PCR protocol was evaluated in 119 FFPE tissues containing septate hyphae or yeast, and Mucorales-specific semi-nested PCR in 126 FFPE tissues containing aseptate hyphae.Results. The DNA yield by conventional PCI method was significantly higher (P<0.0001) than commercial kit, though the quality of DNA was similar by both protocols. The test accuracy was best while using ITS1 (61.9 %) as the target compared to 7.9, 29.9 and 22.2 % on targeting ITS1-5.8S-ITS2, ITS2, the D1/D2 region of 28S, respectively. The test accuracies of ITS1-PCR in tissues containing septate hyphae, aseptate hyphae and yeasts were 75.5, 18.7 and 100 %, respectively. The amplification (targeting ITS1 region) improved by increasing the thickness of tissue section (up to 50 µm) used for DNA extraction. ITS1-PCR protocol could amplify fungal DNA in 76 (63.8 %) tissues and Mucorales-specific semi-nested PCR in 86 (68.3 %) tissues.Conclusion. Conventional PCI-based DNA extraction from thick tissue (50 µm) may be used until optimal commercial fungal DNA extraction kit is developed. Subsequent ITS1-PCR for septate fungi and yeast, and semi-nested PCR targeting 18S rDNA for Mucorales are recommended to identify the fungus in FFPE tissues.

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

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

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.

Diversity of Filamentous Fungi Isolated From Some Amylase and Alcohol-Producing Starters of India

Filamentous fungi are important organisms in traditionally prepared amylase and alcohol-producing dry starters in India. We collected 40 diverse types of amylase and alcohol-producing starters from eight states in North East India viz. marcha, thiat, humao, hamei, chowan, phut, dawdim, and khekhrii. The average fungal population was 4.9 × 10⁵ cfu/g with an average of pH 5.3 and 10.7%, respectively. In the present study, 131 fungal isolates were isolated and characterized based on macroscopic and microscopic characteristics and were grouped into 44 representative fungal strains. Based on results of morphological characteristics and ITS gene sequencing, 44 fungal strains were grouped into three phyla represented by Ascomycota (48%), Mucoromycota (38%), and Basidiomycota (14%). Taxonomical keys to species level was illustrated on the basis of morphological characteristics and ITS gene sequencing, aligned to the fungal database of NCBI GenBank, which showed seven genera with 16 species represented by Mucor circinelloides (20%), Aspergillus sydowii (11%), Penicillium chrysogenum (11%), Bjerkandera adusta (11%), Penicillium citrinum (7%), Rhizopus oryzae (7%), Aspergillus niger (5%), Aspergillus flavus (5%), Mucor indicus (5%) Rhizopus microsporus (5%), Rhizopus delemar (2%), Aspergillus versicolor (2%), Penicillium oxalicum (2%), Penicillium polonicum (2%), Trametes hirsuta (2%), and Cladosporium parahalotolerans (2%). The highest Shannon diversity index H was recorded in marcha of Sikkim (H: 1.74) and the lowest in hamei of Manipur (H: 0.69). Fungal species present in these amylolytic starters are morphologically, ecologically and phylogenetically diverse and showed high diversity within the community.

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

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

Dual production of polyunsaturated fatty acids and beta-carotene with Mucor wosnessenskii by the process of solid-state fermentation using agro-industrial waste

Solid-state fermentation is a technique employing microorganisms grown on a solid substrate in the absence of free water. The substrates used in this process are mostly waste from the agro-industry (brans, spent malt grains, distiller grains, etc.) that improves not only the economy of the process but also has positive effect on waste management problems. Zygomycetous fungi are not only able to grow in such conditions but also enrich fermented materials with various types of bioactive compounds. Mucor sp. strains have been identified as producers of gamma-linolenic acid and beta-carotene in submerged fermentation. The aim of the present study was to identify the best microbial producer of gamma-linolenic acid and beta-carotene among four different Mucor strains and to study the requirements for the dual production of these metabolites. Mucor wosnessenskii was identified as the most suitable producer of both metabolites. After optimization of the fermentation conditions, the highest yields obtained were 10.7 g of gamma-linolenic acid/kg of fermented product and 261.5 mg of beta-carotene/kg of fermented product. This yield of beta-carotene is the highest among the results published so far.

How could hypoglycemia-inducing glycogen storage disease lead to hyperglycemia-induced mucormycosis?

Mucormycosis is an increasingly frequent, difficult to diagnose, difficult to treat, often fatal infection, especially in patients with hyperglycemia from uncontrolled diabetes. Type I (von Gierke) glycogen storage disease is due to inherited deficiency of enzymes in glycogen metabolism, which causes hypoglycemia. This report is the case of a patient with von Gierke disease and a missed diagnosis of pulmonary mucormycosis. This report illustrates the importance of having a high index of suspicion for mucormycosis in the appropriate clinical context.

Isolation and Characterization of Four Unrecorded Mucor Species in Korea

During an investigation of fungi of the order Mucorales from freshwater and sediment samples in Korea, we isolated six strains, NNIBRFG6649, NNIBRFG6255, NNIBRFG1498, CNUFC-YJ13, CNUFC-YR7, and NNIBRFG2739. The morphology and phylogeny of these strains were analyzed. Based on the morphological characteristics and molecular data from internal transcribed spacer (ITS) region, the isolates NNIBRFG6649 and NNIBRFG6255 were identified as Mucor abundans, and M. aligarensis, respectively. The isolates NNIBRFG1498 and CNUFC-YJ13 were identified as M. moelleri, whereas the isolates CNUFC-YR7 and NNIBRFG2739 were identified as M. heterogamus. To the best of our knowledge, M. abundans, M. aligarensis, M. moelleri, and M. heterogamus have not yet been reported in Korea.

Outbreaks of Mucorales and the Species Involved

The order Mucorales is an ancient group of fungi classified in the subphylum Mucoromycotina. Mucorales are mainly fast-growing saprotrophs that belong to the first colonizers of diverse organic materials and represent a permanent part of the human environment. Several species are able to cause human infections (mucormycoses) predominantly in patients with impaired immune system, diabetes, or deep trauma. In this review, we compiled 32 reports on community- and hospital-acquired outbreaks caused by Mucorales. The most common source of mucoralean outbreaks was contaminated medical devices that are responsible for 40.7% of the outbreaks followed by contaminated air (31.3%), traumatic inoculation of soil or foreign bodies (9.4%), and the contact (6.2%) or the ingestion (6.2%) of contaminated plant material. The most prevalent species were Rhizopus arrhizus and R. microsporus causing 57% of the outbreaks. The genus Rhizomucor was dominating in outbreaks related to contaminated air while outbreaks of Lichtheimia species and Mucor circinelloides were transmitted by direct contact. Outbreaks with the involvement of several species are reported. Subtyping of strains revealed clonality in two outbreaks and no close relation in two other outbreaks. Based on the existing data, outbreaks of Mucorales can be caused by heterogeneous sources consisting of different strains or different species. Person-to-person transmission cannot be excluded because Mucorales can sporulate on wounds. For a better understanding and prevention of outbreaks, we need to increase our knowledge on the physiology, ecology, and population structure of outbreak causing species and more subtyping data.

Gastrointestinal Mucormycosis in a two-year-old child: A clinical and radiological enigma

Mucormycosis is a rare, fatal angioinvasive infection occurring in immunocompromised individuals. Gastrointestinal mucormycosis is rare variety with high mortality rate. We present a case of GI mucormycosis in a 2-year-old male child who presented with abdominal mass with no underlying risk factors. The aim of this case report is to emphasize on its etiopathogenesis and keeping mucormycosis high in the differential diagnosis in a child presenting with abdominal mass.

Intravenous and Oral Posaconazole Pharmacokinetics in a Five-Year-Old With Mucor: A Case Report and Review of the Literature

Posaconazole is a lipophilic triazole antifungal that exhibits variable absorption when administered orally. It possesses a broad spectrum of activity against various fungi, such as Aspergillus and traditionally resistant molds such as Rhizopus and Mucor, which carry a poor prognosis. Unfortunately, the tablet and suspension formulations of posaconazole are Food and Drug Administration approved for treatment of fungal diseases only in patients older than 13 years of age. Furthermore, the approval of the IV formulation is exclusively for adult patients. Nevertheless, the extended spectrum of activity and available dosage forms make it an attractive option for pediatric use. The data that exist to guide dosing of posaconazole in young pediatric patients are limited primarily to case series and case reports. Thus, we recommend therapeutic drug monitoring to ensure both safety and efficacy in pediatric patients. Herein we describe our experience with both oral and IV posaconazole in the salvage therapy of a 5-year-old female with extensive cutaneous Mucor. In contrast to previous reports, which show larger doses may be necessary to obtain therapeutic concentrations in pediatric patients as compared with adults, our patient reached targeted concentrations with weight-based dosing.

Therapeutic Challenges of Non-Aspergillus Invasive Mold Infections in Immunosuppressed Patients

While Aspergillus spp. remain the major cause of invasive mold infections in hematologic cancer patients and transplant recipients, other opportunistic molds, such as Mucorales, Fusarium, and Scedosporium spp. are increasingly encountered in an expanding population of patients with severe and prolonged immunosuppression. High potential for tissue invasion and dissemination, resistance to multiple antifungals and high mortality rates are hallmarks of these non-Aspergillus invasive mold infections (NAIMIs). Assessment of drug efficacy is particularly difficult in the complex treatment scenarios of NAIMIs. Specifically, correlation between in vitro susceptibility and in vivo responses to antifungals is hard to assess, in view of the multiple, frequently interrelated factors influencing outcomes, such as pharmacokinetic/pharmacodynamic parameters determining drug availability at the site of infection, the net state of immune suppression, delay in diagnosis, or surgical debulking of infectious foci. Our current therapeutic approach of NAIMIs should evolve toward a better integration of the dynamic interactions between the pathogen, the drug and the host. Innovative concepts of experimental research may consist in manipulating the host immune system to induce a specific antifungal response or targeted drug delivery. In this review, we discuss the challenges in the management of NAIMIs and provide an update about the latest advances in diagnostic and therapeutic approaches.