Zygomycetes in human disease

A Repertoire of Clinical Non-Dermatophytes Moulds

Humans are constantly exposed to micromycetes, especially filamentous fungi that are ubiquitous in the environment. In the presence of risk factors, mostly related to an alteration of immunity, the non-dermatophyte fungi can then become opportunistic pathogens, causing superficial, deep or disseminated infections. With new molecular tools applied to medical mycology and revisions in taxonomy, the number of fungi described in humans is rising. Some rare species are emerging, and others more frequent are increasing. The aim of this review is to (i) inventory the filamentous fungi found in humans and (ii) provide details on the anatomical sites where they have been identified and the semiology of infections. Among the 239,890 fungi taxa and corresponding synonyms, if any, retrieved from the Mycobank and NCBI Taxonomy databases, we were able to identify 565 moulds in humans. These filamentous fungi were identified in one or more anatomical sites. From a clinical point of view, this review allows us to realize that some uncommon fungi isolated in non-sterile sites may be involved in invasive infections. It may present a first step in the understanding of the pathogenicity of filamentous fungi and the interpretation of the results obtained with the new molecular diagnostic tools.

Mucormycosis, past and present: a comprehensive review

Mucormycosis is an emerging opportunistic angioinvasive fungal infection. Predisposing factors such as diabetes, neutropenia, long-term corticosteroid therapy, solid organ transplantation and immunosuppression contribute to its occurrence. This disease was not of significant concern prior to the COVID-19 pandemic, but gained prominence due to infections in COVID-19 patients. Mucormycosis needs special attention and coordinated efforts of the scientific community and medical professionals to reduce morbidity and mortality. Here we present an overview of the epidemiology and prevalence of mucormycosis in the pre- and post-COVID-19 eras, the factors that contributed to the abrupt increase in COVID-19-associated mucormycosis (CAM), the actions taken by the regulatory agencies (including Code Mucor and CAM registry), the existing diagnostic tools and CAM management strategies.

Discovery of a New Lichtheimia (Lichtheimiaceae, Mucorales) from Invertebrate Niche and Its Phylogenetic Status and Physiological Characteristics

Species of Lichtheimia are important opportunistic fungal pathogens in the order Mucorales that are isolated from various sources such as soil, indoor air, food products, feces, and decaying vegetables. In recent years, species of Lichtheimia have become an emerging causative agent of invasive mucormycosis. In Europe and USA, Lichtheimia are the second and third most common causal fungus of mucormycosis, respectively. Thus, the aim of this study was to survey the diversity of species of Lichtheimia hidden in poorly studied hosts, such as invertebrates, in Korea. Eight Lichtheimia strains were isolated from invertebrate samples. Based on morphology, physiology, and phylogenetic analyses of ITS and LSU rDNA sequence data, the strains were identified as L. hyalospora, L. ornata, L. ramosa, and a novel species, L. koreana sp. nov. Lichtheimia koreana is characterized by a variable columellae, sporangiophores arising solitarily or up to three at one place from stolons, and slow growth on MEA and PDA at all temperatures tested. The new species grows best at 30 and 35 °C and has a maximum growth temperature of 40 °C. Detailed descriptions, illustrations, and a phylogenetic tree are provided.

A peek behind the curtain in the diagnosis and management of COVID‑19‑Associated Mucormycosis (CAM)

Coronavirus disease 2019 (COVID-19)-associated mucormycosis (CAM) is responsible for a high mortality rate due to its unique and severe host-pathogen interactions. Critically ill or immunocompromised COVID-19 patients are more prone to suffer from aggressive mycoses. Probable victims include those with uncontrolled diabetes mellitus (DM), metabolic acidosis, prolonged neutropenia, increased ferritin levels, hypoxia, and prolonged hospitalization with/without mechanical ventilators and corticosteroids administration. The current review aims to outline the journey of patients with CAM as well as the advantages and disadvantages of the currently available diagnostic techniques. It also discussed the current status of treatment options and caveats in the management of mucormycosis. Multidisciplinary team, early diagnosis, controlling the predisposing condition(s), complete surgical debridement, effective antifungal therapies (e.g., amphotericin B, isavuconazole, and posaconazole), and implementing antifungal stewardship programs are imperative in CAM cases.

Neuromucormycosis of Posterior Tibial Nerve: A Rare Presentation of Mucormycosis

Opportunistic fungal infections are known to occur in immunocompromised patients. Mucormycosis is one of the most common opportunistic fungal infections with significant mortality rates. In this article, we present a case of an adult female, a known diabetic who presented with fever and pus discharge from the amputation site of toes in the left foot with blackening of the foot. Examination revealed gangrenous changes of the left foot with no distal pulses palpable. Computed tomography angiogram revealed no flow of blood in distal vessels of the left lower limb. Left below knee guillotine amputation was done. Intraoperative biopsy of the neurovascular bundle revealed invasive neuromucormycosis. She was started on liposomal amphotericin B. The wound started granulating after a few days with serial dressings and the patient was planned for split skin grafting.

A retrospective analysis for the management of oromaxillofacial invasive mucormycosis and systematic literature review

PURPOSE

Mucormycosis is a type of fatal infectious disease, rarely involved in the oromaxillofacial region. This study aimed to describe a series of 7 cases with oromaxillofacial mucormycosis and to discuss the epidemiology, clinical features, and treatment algorithm thereof.

METHODOLOGY

Seven patients in the author's affiliation have been treated. They were assessed and presented as per their diagnostic criteria, surgical approach, and mortality rates. Reported cases of mucormycosis originally happened in craniomaxillofacial region were synthesized through a systematic review so as to better discuss its pathogenesis, epidemiology, and management.

RESULTS

Six patients had a primary metabolic disorder, and one immunocompromised patient had a history of aplastic anemia. The criteria for a positive diagnosis of invasive mucormycosis were based on clinical presentation of signs and symptoms, and a biopsy for microbiological culture and histopathologic analysis. Each patient used antifungal drugs and five of them also underwent surgical resection at the same time. Four patients died due to the unregulated spread of mucormycosis, and one patient died owing to her main disease.

CONCLUSIONS

Although uncommon in clinical practice setting, mucormycosis should be of great concern in oral and maxillofacial surgery, due to the life-threatening possibility of this disease. The knowledge of early diagnosis and prompt treatment is of utmost importance for saving lives.

Surge of mucormycosis during the COVID-19 pandemic

Patients with respiratory viral infections are more likely to develop co-infections leading to increased fatality. Mucormycosis is an epidemic amidst the COVID-19 pandemic that conveys a 'double threat' to the global health fraternity. Mucormycosis is caused by the Mucorales group of fungi and exhibits acute angioinvasion generally in immunocompromised patients. The most familiar foci of infections are sinuses (39%), lungs (24%), and skin tissues (19%) where the overall dissemination occurs in 23% of cases. The mortality rate in the case of disseminated mucormycosis is found to be 96%. Symptoms are mostly nonspecific and often resemble other common bacterial or fungal infections. Currently, COVID-19-associated mucormycosis (CAM) is being reported from a number of countries such as the USA, Turkey, France, Mexico, Iran, Austria, UK, Brazil, and Italy, while India is the hotspot for this deadly co-infection, accounting for approximately 28,252 cases up to June 8, 2021. It strikes patients within 12-18 days after COVID-19 recovery, and nearly 80% require surgery. Nevertheless, the mortality rate can reach 94% if the diagnosis is delayed or remains untreated. Sometimes COVID-19 is the sole predisposing factor for CAM. Therefore, this study may provide a comprehensive resource for clinicians and researchers dealing with fungal infections, intending to link the potential translational knowledge and prospective therapeutic challenges to counter this opportunistic pathogen.

Impact of diet and host genetics on the murine intestinal mycobiome

The mammalian gut is home to a diverse microbial ecosystem, whose composition affects various physiological traits of the host. Next-generation sequencing-based metagenomic approaches demonstrated how the interplay of host genetics, bacteria, and environmental factors shape complex traits and clinical outcomes. However, the role of fungi in these complex interactions remains understudied. Here, using 228 males and 363 females from an advanced-intercross mouse line, we provide evidence that fungi are regulated by host genetics. In addition, we map quantitative trait loci associated with various fungal species to single genes in mice using whole genome sequencing and genotyping. Moreover, we show that diet and its' interaction with host genetics alter the composition of fungi in outbred mice, and identify fungal indicator species associated with different dietary regimes. Collectively, in this work, we uncover an association of the intestinal fungal community with host genetics and a regulatory role of diet in this ecological niche.

COVID associated pulmonary mucormycosis: Outcomes of surgical therapy

OBJECTIVES

This study aims at reporting the surgical outcomes of COVID associated pulmonary mucormycosis with special emphasis on surgical mortality.

METHODS

This prospective observational study was conducted in a dedicated thoracic surgical unit in Gurugram, India over 18 months. An analysis of demography, peri-operative variables were carried out. Various parameters were analysed to assess the factors affecting mortality.

RESULTS

Total of 44 patients with diagnosis of CAPM were managed during the study period. All were started on anti-fungal therapy. However, 33 patients (75%) were operated whereas rest 11 (25%) were not considered suitable for surgery. In the surgical cohort (n  =  33), there were 20 males (60.6%) and 13 females (39.4%), with a mean age of 54.8 years (range, 33-72 years). The mean duration of the symptoms was 1.1 weeks. Non-anatomical wedge resection of lobe(s) was performed in 5 patients (15.1%), lobectomy/bi-lobectomy was required in 26 patients (78.9%) and left pneumonectomy in 2 patients (6%). There were 5 peri-operative deaths (15.1%), all due to fungal sepsis. ECOG scale > 2 (P  ≤  0.001), higher Charlson Comorbidity Index score > 2 (P  =  0.04) and pneumonectomy (P  =  0.02) were the predictors of mortality. On comparison with NCPM, there was no difference in the incidence of post-operative complications (P  =  0.50) and the post-operative mortality (P  =  0.69).

CONCLUSION

Aggressive surgical resection with clear margins should be offered in CAPM, whenever feasible. Surgery for CAPM was not associated with higher post-operative complications including mortality compared to Non-COVID Pulmonary Mucormycosis.

A Multiplex PCR and DNA-Sequencing Workflow on Serum for the Diagnosis and Species Identification for Invasive Aspergillosis and Mucormycosis

There has been significant increase in the use of molecular tools for the diagnosis of invasive aspergillosis (IA) and mucormycosis. However, their range of detection may be too limited as species diversity and coinfections are increasing. Here, we aimed to evaluate a molecular workflow based on a new multiplex PCR assay detecting the whole Aspergillus genus and the Mucorales order followed by a species-specific PCR or a DNA-sequencing approach for IA and/or mucormycosis diagnosis and species identification on serum. Performances of the MycoGENIE Aspergillus spp./Mucorales spp. duplex PCR kit were analyzed on a broad range of fungal strains and on sera from high-risk patients prospectively over a 12-month period. The kit allowed the detection of nine Aspergillus species and 10 Mucorales (eight genera) strains assessed. No cross-reactions between the two targets were observed. Sera from 744 patients were prospectively analyzed, including 35 IA, 16 mucormycosis, and four coinfections. Sensitivity varies from 85.7% (18/21) in probable/proven IA to 28.6% (4/14) in COVID-19-associated pulmonary aspergillosis. PCR-positive samples corresponded to 21 A. fumigatus, one A. flavus, and one A. nidulans infections. All the disseminated mucormycosis were positive in serum (14/14), including the four Aspergillus coinfections, but sensitivity fell to 33.3% (2/6) in localized forms. DNA sequencing allowed Mucorales identification in serum in 15 patients. Remarkably, the most frequent species identified was Rhizomucor pusillus (eight cases), whereas it is barely found in fungal culture. This molecular workflow is a promising approach to improve IA and mucormycosis diagnosis and epidemiology.

A rare case of pediatric gastrointestinal mucormycosis with a review of the literature

This manuscript discusses a rare case of pediatric gastrointestinal mucormycosis in a hospitalized patient who presented in diabetic ketoacidosis. A review of the literature is summarized to provide an overview of mucormycosis with a discussion of the mechanisms underlying the susceptibility of diabetic patients for this condition.

Rhino-orbital mucormycosis in a Mexican patient with COVID-19: Case report

BACKGROUND

A variety of bacterial and fungal co-infections may be attributed to the coronavirus disease 2019 (COVID-19), particularly in people who already have a medical condition such diabetes mellitus or those who received large dosages of steroids.

CASE REPORT

We described a 52-year-old diabetic man who was receiving high doses of dexamethasone and antibiotics while receiving ambulatory care for COVID-19 pneumonia. His anterior rhinoscopy revealed a necrotic scab, and a sample confirmed Mucor spp. He underwent surgery and was given amphotericin as a result of the severity of the condition, palpebral ptosis, and right ocular palsy he was experiencing. The patien ́s progression was satisfactory.

CONCLUSIONS

pre-existing diabetes mellitus, previous steroid and antimicrobial use, as well as SARS-CoV-2 infection are some of the risk factors associated with Mucor spp. infection. Prompt detection of mucormycosis is important in the management of these affected patients.

Antifungal Activity of Plant Secondary Metabolites on Candida albicans: An Updated Review

Fungal infections have been increasing continuously worldwide, especially in immunocompromised individuals. Fungi, regarded as eukaryotic pathogens, have many similarities to the host cells, which inhibit anti-fungal drug development progress. Various fungal model systems have been studied, and it was concluded that Candida spp. is the most common disease-causing fungus. Candida species are well known to cause infections not only in our mouth, skin, and vagina, but they are also a frequent cause of life-threatening hospital bloodstream infections. The morphological and developmental pathways of Candida have been studied extensively, providing insight into the fungus development. Candida albicans is known to be the most pathogenic species responsible for a variety of infections in humans. Conventional anti-fungal drugs, mainly azoles drugs available in the market, have been used for years developing resistance in C. albicans. Hence, the production of new anti-fungal drugs, which require detailed molecular knowledge of fungal pathogenesis, needs to be encouraged. Therefore, this review targets the new approach of "Green Medicines" or the phytochemicals and their secondary metabolites as a source of novel anti-fungal agents to overcome the drug resistance of C. albicans, their mechanism of action, and their combined effects with the available anti-fungal drugs.

A Proposed Diagnostic Algorithm for Fungal Orbital Infections after 20 Years of Experience in a Tertiary Eye Care Center- Egypt

METHOD

Medical Records of cases with orbital fungal infection from January 2000 to December 2019 were reviewed.

RESULTS

The study included 45 patients. Mucormycosis was proven in 32 (71.1%) and aspergillosis in 13 (28.9%) patients. Thirty-five (77.8%) patients had predisposing factors mainly uncontrolled diabetes. Twenty-seven (60%) patients presented with orbital apex syndrome, 10 (22.2%) with orbital cellulitis and 8 (17.7%) with proptosis. The prognosis was generally poor (31.1% mortality, 8.88% exenteration and 11.1% self-evisceration). The proposed algorithm composed of six atypical clinical presentations mainly acute orbital apex and fulminating orbital cellulitis plus any radiological or microbiological findings.

CONCLUSION

The proposed algorithm markedly reduced the complications after 5 years of the study. Once fungal orbital infection is suspected, treatment should start immediately.

Focusing COVID-19-associated mucormycosis: a major threat to immunocompromised COVID-19

COVID-19 disease has been identified to cause remarkable increase of mucormycosis infection cases in India, with the majority of cases being observed in individuals recovering from COVID-19. Mucormycosis has emanated as an outcome of the recent COVID-19 pandemic outbreak as rapidly developing fatal illness which was acquired by Mucorales fungus which is a subcategory of molds known as mucormycetes. Mucormycosis is one of the serious, sporadic mycotic illnesses which is a great threat to immunocompromised COVID-19 patients and affects people of all ages, including children with COVID-19 infections. This is associated with tissue damaging property and, therefore, causes serious clinical complications and elevated death rate. The COVID-19-associated mucormycosis or "black fungus" are the terms used interchangeably. The rapid growth of tissue necrosis presenting as "rhino-orbital-cerebral, pulmonary, cutaneous, gastrointestinal, and disseminated disease" are various clinical forms of mucormycosis. The patient's prognosis and survival can be improved with proper surgeries using an endoscopic approach for local tissue protection in conjunction with course of appropriate conventional antifungal drug like Amphotericin-B and novel drugs like Rezafungin, encochleated Amphotericin B, Orolofim, and SCY-078 which have been explored in last few years. This review provides an overview of mucormycosis including its epidemiology, pathophysiology, risk factors, its clinical forms, and therapeutic approaches for disease management like antifungal therapy, surgical debridement, and iron chelators. The published patents and ongoing clinical trials related to mucormycosis have also been mentioned in this review.

Reddy H, AR S. Coronavirus Disease 2019-Associated Cerebral Mucormycosis in an Immunocompetent Child

Mucormycosis is a rare opportunistic fungal infection observed in immunocompromised individuals or in those with uncontrolled diabetes mellitus. During the coronavirus disease 2019 (COVID-19) pandemic, there has been a steep increase in the incidence of mucormycosis among adults. However, the infection is extremely rare in the pediatric population, and its occurrence post-COVID-19 infection has been reported in very few cases. We present a case of cerebral mucormycosis in a 6-year-old immunocompetent girl that was histopathologically confirmed by stereotactic brain biopsy. The fungal infection occurred following asymptomatic COVID-19 infection and this report describes the diagnostic journey and management. It highlights the unusual presentation of cerebral mucormycosis in our case and the role of posaconazole in the successful treatment.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Is the production of reactive oxygen and nitrogen species by macrophages associated with better infectious control in female mice with experimentally disseminated and pulmonary mucormycosis?

Different levels of resistance against Rhizopus oryzae infection have been observed between inbred (BALB/c) and outbred (Swiss) mice and are associated with the genetic background of each mouse strain. Considering that macrophages play an important role in host resistance to Rhizopus species, we used different infectious outcomes observed in experimental mucormycosis to identify the most efficient macrophage response pattern against R. oryzae in vitro and in vivo. For this, we compared BALB/c and Swiss macrophage activity before and after intravenous or intratracheal R. oryzae infections. The production of hydrogen peroxide (H2O2) and nitric oxide (NO) was determined in cultures of peritoneal (PMΦ) or alveolar macrophages (AMΦ) challenged with heat-killed spores of R. oryzae. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10) were measured to confirm our findings. Naïve PMΦ from female BALB/c mice showed increased production of H2O2, TNF-α, and IL-10 in the presence of heat-killed spores of R. oryzae. Naïve PMΦ from female Swiss mice were less responsive. Naïve AMΦ from the two strains of female mice were less reactive to heat-killed spores of R. oryzae than PMΦ. After 30 days of R. oryzae intravenous infection, lower fungal load in spleen from BALB/c mice was accompanied by higher production of H2O2 by PMΦ compared with Swiss mice. In contrast, AMΦ from BALB/c mice showed higher production of NO, TNF-α, and IL-10 after 7 days of intratracheal infection. The collective findings reveal that, independent of the female mouse strain, PMΦ is more reactive against R. oryzae upon first contact than AMΦ. In addition, increased PMΦ production of H2O2 at the end of disseminated infection is accompanied by better fungal clearance in resistant (BALB/c) mice. Our findings further the understanding of the parasite-host relationship in mucormycosis.

Identification of novel inhibitors of high affinity iron permease (FTR1) through implementing pharmacokinetics index to fight against black fungus: An in silico approach

Mucormycosis is a life-threatening fungal infection, particularly in immunocompromised patients. Mucormycosis has been reported to show resistance to available antifungal drugs and was recently found in COVID-19 as a co-morbidity that demands new classes of drugs. In an attempt to find novel inhibitors against the high-affinity iron permease (FTR1), a novel target having fundamental importance on the pathogenesis of mucormycosis, 11,000 natural compounds were investigated in this study. Virtual screening and molecular docking identified two potent natural compounds [6',7,7,10',10',13'-hexamethylspiro[1,8-dihydropyrano[2,3-g]indole-3,11'-3,13-diazatetracyclo[5.5.2.01,9.03,7]tetradecane]-2,9,14'-trione and 5,7-dihydroxy-3-(2,2,8,8-tetramethylpyrano[2,3-f]chromen-6-yl)chromen-4-one] that effectively bind to the active cavity of FTR1 with a binding affinity of -9.9 kcal/mol. Multiple non-covalent interactions between the compounds and the active residues of this cavity were noticed, which is required for FTR1 inhibition. These compounds were found to have inhibitory nature and meet essential requirements to be drug-like compounds with a considerable absorption, distribution, metabolism, and excretion (ADME) profile with no toxicity probabilities. Molecular dynamics simulation confirms the structural compactness and less conformational variation of the drug-protein complexes maintaining structural stability and rigidity. MM-PBSA and post-simulation analysis predict binding stability of these compounds in the active cavity. This study hypothesizing that these compounds could be a potential inhibitor of FTR1 and will broaden the clinical prospects of mucormycosis.

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.

An old confusion: Entomophthoromycosis versus mucormycosis and their main differences

Fungal diseases were underestimated for many years. And the global burden of fungal infections is substantial and has increased in recent years. Invasive fungal infections have been linked to several risk factors in humans which basically depend on the individual homeostasis of the patients. However, many fungi can infect even apparently healthy people. Knowledge of these pathogens is critical in reducing or stopping morbidity and/or mortality statistics due to fungal pathogens. Successful therapeutic strategies rely on rapid diagnosis of the causative fungal agent and the underlying disease. However, the terminology of the diseases was updated to existing phylogenetic classifications and led to confusion in the definition of mucormycosis, conidiobolomycosis, and basidiobolomycosis, which were previously grouped under the now-uncommon term zygomycosis. Therefore, the ecological, taxonomic, clinical, and diagnostic differences are addressed to optimize the understanding and definition of these diseases. The term "coenocytic hyphomycosis" is proposed to summarize all fungal infections caused by Mucorales and species of Basidiobolus and Conidiobolus.

Potential inhibitory activity of phytoconstituents against black fungus: In silico ADMET, molecular docking and MD simulation studies

Mucormycosis or “black fungus” has been currently observed in India, as a secondary infection in COVID-19 infected patients in the post-COVID-stage. Fungus is an uncommon opportunistic infection that affects people who have a weak immune system. In this study, 158 antifungal phytochemicals were screened using molecular docking against glucoamylase enzyme of Rhizopus oryzae to identify potential inhibitors. The docking scores of the selected phytochemicals were compared with Isomaltotriose as a positive control. Most of the compounds showed lower binding energy values than Isomaltotriose (-6.4 kcal/mol). Computational studies also revealed the strongest binding affinity of the screened phytochemicals was Dioscin (-9.4 kcal/mol). Furthermore, the binding interactions of the top ten potential phytochemicals were elucidated and further analyzed. In-silico ADME and toxicity prediction were also evaluated using SwissADME and admetSAR online servers. Compounds Piscisoflavone C, 8-O-methylaverufin and Punicalagin exhibited positive results with the Lipinski filter and drug-likeness and showed mild to moderate of toxicity. Molecular dynamics (MD) simulation (at 300 K for 100 ns) was also employed to the docked ligand-target complex to explore the stability of ligand-target complex, improve docking results, and analyze the molecular mechanisms of protein-target interactions.

A case of COVID-19-associated rhino-orbito-cerebral mucormycosis caused by Apophysomyces variabilis with a review of the literature

A fatal case of COVID-19-associated mucormycosis (CAM) affected a 40-year-old woman who was initially admitted to our hospital due to a SARS-CoV-2 infection. Her clinical condition worsened, and she finally died because of respiratory failure, hemodynamic instability, and mucormycosis with invasion into the orbit and probably the brain. According to DNA sequence analysis of the fungus isolated from the patient, Apophysomyces variabilis was involved. This is the first published case of CAM and the third case of mucormycosis due to this mold.

Retrobulbar Amphotericin B Injection in Curbing the Progression of COVID Associated Rhino-orbital Cerebral Mucormycosis: A Retrospective Case Series

Purpose To assess whether transcutaneous retrobulbar Amphotericin B (TRAMB) injection can halt disease progression and reduce the requirement of exenteration in post-COVID 19 Rhino-orbital cerebral Mucormycosis (ROCM)) with limited orbital disease. Methods Retrospective series from a single center included 22 patients with KOH proved post-COVID 19 ROCM with radiographic evidence of limited orbital involvement were evaluated from May 2021 to October 2021. TRAMB was given along with systemic intravenous Amphotericin B injection and sinus debridement. Demographic profile, clinical data, operative notes, blood and radiological investigations were evaluated. The primary outcome was to assess the halt in the progression of orbital disease. The primary outcome measure was to assess the halt of the disease progression and the secondary outcome was improvement in the clinical signs and symptoms. Results The mean age was 50.36 ± 9.72 years and 77.3% were men. The Stagewise distribution was twelve (54.5%) patients in stage 3a, four (18.2%) patients in stage 3b, four (18.2%) in stage 3c, one (4.5%) patient in stage 3d and one (4.5%) had stage 4 disease. Improvement in lid edema and conjunctival chemosis were noticed and it was statistically significant (p value < 0.01), similarly visual acuity and ocular motility showed significant improvements (p value 0.04 and < 0.01 respectively). 1 patient died and 1 patient required exenteration later. Twenty patients showed halting of orbital disease after TRAMB injection. Conclusion TRAMB can be an alternative adjuvant therapeutic option to preserve the globe in patients with limited orbital disease but not at all replacement for exenteration.

A Rare Fungal Orbital Infection in an Immunocompetent Young Male Caused by Lichtheimia corymbifera (Absidia corymbifera)

AIM

To present a case of orbital fungal infection caused by a rare fungus, Lichtheimia corymbifera (Absidia corymbifera) in an immunocompetent individual.

MATERIALS AND METHODS

A retrospective case study.

RESULT

A 23-year-old male presented with painful proptosis of the right eye for 3 months. Examination revealed normal vision and pupillary light reflex but restricted ocular movements in the right eye. A tender, firm mass was palpable along the inferomedial quadrant of the right orbit. He had acute worsening of proptosis with loss of light perception within 24 hours. Magnetic resonance imaging (MRI) showed a heterogeneously enhancing lesion in the right orbit. Urgent incisional biopsy revealed the growth of Absidial fungal infection. He received intravenous Amphotericin B for 2 weeks with no response. Repeat MRI revealed an extension of the infection up to the cavernous sinus and intracranial optic nerve. He was managed by subtotal exenteration, socket irrigation with Amphotericin B, and intravenous Amphotericin B.

CONCLUSION

Invasive orbital fungal infection, though rare, should be considered a differential diagnosis in immunocompetent patients with fulminant proptosis and vision loss.

Incidence of Mucormycosis in a Tertiary Care Hospital During Covid First Wave-A Retrospective Study

Rhino orbital cerebral mucormycosis is a medical emergency; though rare it's a life threatening infection in patients. It commonly occurs in immunocompromised patients due to various causes. A retrospective study was conducted in tertiary care centre wherein 30 non-covid, diabetic patients were treated for mucormycosis. All underwent intensive debridement and diabetic management along with antifungal- amphotericin. All the cases improved with aggressive therapy: medical and surgical. Early recognition and treatment is needed to prevent morbidity and mortality.

Role of COVID 19 Inflammatory Markers in Rhino-Orbito-Cerebral Mucormycosis: A Case Study in Predisposed Patients at a Designated Nodal Centre

Mucormycosis is a very morbid and potentially life threatening fungal infection. Sudden emergence and rapidly increasing numbers, of an otherwise rare infection in active Corona virus disease 2019 (COVID-19) or recently recovered patients has made us question the cause for this epidemic in India. This retrospective cohort study was done at Government Ear, Nose and Throat (ENT) hospital, Hyderabad, a designated nodal centre for mucormycosis for the state of Telangana, between April 2021 and June 2021. This study included patients with mucormycosis who had a recent history of COVID-19 infection. Potential predisposing factors (diabetes mellitus, history of oxygen and corticosteroids usage) and inflammatory marker values, predominantly deranged in COVID-19 infection (D-dimer and Serum Ferritin) were evaluated. A correlation between the marker values and susceptibility factors was also studied. Majority of these subjects showed elevated serum markers and had one or more of the predisposing factors for COVID-19 associated mucormycosis (CAM). A significant association was found between elevated marker values and susceptibility factors (diabetes, use of oxygen). Contrary to the popular belief, that the inadvertent use of steroids, use of industrial oxygen or elevated blood sugars caused this epidemic, our study concludes that their role is limited to affecting the extent of morbidity/mortality. B.1.1.7 and B.6.117 variants of severe acute respiratory syndrome coronavirus 2 (SARSCoV2), predominant during the second wave in India, facilitated the fungal invasion and spread by altering the gene expression and inducing inflammatory and immunomodulatory changes.

Pathogenesis and Pathology of COVID-Associated Mucormycosis: What Is New and Why

Purpose of Review

There is global increase in the incidence of mucormycosis. However, a sudden increase in the COVID-associated mucormycosis (CAM) was noted, particularly in India, during the second wave of the COVID-19 pandemic. The interplay of factors involved in the pathogenesis is complex. In this review, the influence of pre-existing disease, exaggerated risk factors, altered milieu due to COVID-19 itself and the consequences of its treatment on the host pathogen interactions leading to the disease and morphology of the fungus will be highlighted.

Recent Findings

Hyperglycemia, acidosis, available free iron, lowered host defenses, and the fungal virulence factors promote the growth of Mucorales. There is a high background prevalence of diabetes mellitus (DM) in India. Uncontrolled or undiagnosed DM, COVID-19 itself, and inappropriate administration of corticosteroids in high doses and for prolonged periods result in hyperglycemia. Diabetic ketoacidosis (DKA) and metabolic acidosis due to hypoxia or renal failure contribute to acidic pH and dissociate bound iron from serum proteins. The host defenses are lowered due to COVID-19-induced immune dysregulation, hyperglycemia itself, and administration of corticosteroids and immune suppressants for the treatment of COVID-19. The altered metabolic milieu in the local microenvironment of nose and paranasal sinuses (PNS) promotes specific interaction of glucose-regulated protein-78 (GRP-78) on host cells with spore coat protein homologue (CotH 3) on Mucorales resulting in rhino-orbito-cerebral mucormycosis (ROCM) as the predominant clinical form in CAM. The pathology is extensive soft tissue involvement with angioinvasion and perineural invasion. Melanized hyphae and sporangia were seen on histopathology, which is unique to CAM. While many factors favor the growth of Mucorales in CAM, hyperglycemia, hyperferritinemia, and administration of hyperbaric oxygen result in reactive oxygen species (ROS) and inadequate humidification results in dehydration. Melanization is possibly the adaptive and protective mechanism of Mucorales to escape the unfavorable conditions due to the treatment of COVID-19.

Summary

High background prevalence of DM, inappropriate administration of corticosteroids and immune dysregulation due to COVID-19 favor the growth of Mucorales in CAM. Melanization of Mucorales hyphae and sporangia on histopathology probably represent adaptive and protective mechanism due to the treatment with hyperbaric oxygen with inadequate humidification as well as the metabolic alterations.

Bronchial wall necrosis secondary to mucormycosis following SARS-Cov2 infection: A case report

Coronavirus 2019 infection (COVID-19) has a broad spectrum of clinical complications, some unrecognized. Herein, a case of a diabetic patient with multiple episodes of hemoptysis 2 months following her recovery from SARS-CoV-2 infection is reported. The initial computed tomography (CT scan) revealed the left lower lobe collapsed secondary to bronchial narrowing and obliteration. Bronchoscopy was performed, indicating necrotic endobronchial tissue, which was confirmed histopathologically as invasive mucormycosis. Bronchial necrosis due to mucormycosis is an unusual presentation of COVID-19-associated pulmonary mucormycosis. The accurate diagnosis could be challenging as it can resemble other pathologies such as malignancies. Therefore, it is crucial to identify this fatal complication in patients with prolonged COVID-19 and lung collapse.

Clinical characteristics and outcome of mucormycosis: A multi-center retrospective analysis in Saudi Arabia over 11 years

Background

Mucormycosis is a life-threatening fungal infection with variable epidemiology between countries. Limited data are available locally; we aim to describe the clinical spectrum and outcome of mucormycosis in Saudi Arabia.

Methods

A retrospective multi-center study including all patients with clinical and pathological evidence of mucormycosis in 3 tertiary care centers in Saudi Arabia from January 2009 to December 2019.

Results

Thirty-three patients were identified during the study period. The mean age was 42 years. People with diabetes accounted for 48% of the patient population. The most common site of infection was cutaneous (27%), followed by isolated sinusitis (21%) and pulmonary and rhino-orbital-cerebral mucormycosis (each 18%). The most common isolated species were Rhizopus (50%) and Mucor (15%). Most patients received medical therapy with amphotericin B (79%), and more than half were treated surgically. The 1-year mortality rate reached 48%, with higher mortality observed in disseminated and rhino-orbital-cerebral infections than in other sites.

Conclusion

Our study addressed the epidemiology of mucormycosis in Saudi Arabia and showed comparable patterns of clinical and mycological aspects to worldwide reports. Further studies are needed to evaluate mucormycosis risk factors and prognosis based on the species, site of infection and therapy type.

Use of different stains for microscopic evaluation for the diagnosis of Pythium keratitis

PURPOSE

To evaluate the efficacy of various staining techniques for detection of Pythium in keratitis cases.

METHODS

Data of nineteen consecutive culture-positive cases of Pythium keratitis were retrospectively analysed. Corneal scrapings and corneal buttons (in the cases which underwent therapeutic penetrating keratoplasty [TPK]) were sent for microbiological and histopathological examination. The direct smears were stained with Potassium hydroxide and calcofluor white (KOH ​+ ​CFW), Gram and Iodine-Potassium Iodide-Sulphuric Acid (IKI-H₂SO₄) stains. The corneal buttons were stained with Gomori's Methanamine Silver (GMS), Periodic Acid-Schiff (PAS) and Iodine-Potassium Iodide-Sulphuric Acid (IKI-H₂SO₄) stains. The positivity of various stains in detecting Pythium was studied.

RESULTS

Gram and KOH ​+ ​CFW staining from smear was done in 16 out of 19 (84.2%) cases. KOH ​+ ​CFW and Gram stains were suggestive of Pythium in 10 (62.5%) and 7 (43.8%) cases, respectively. IKI-H₂SO₄ staining in scraping samples was positive for Pythium in all the 4 (100%) cases in which it was performed. Half corneal buttons were positive for Pythium with IKI-H₂SO₄ stain as well as GMS stain in all the 18 cases that underwent TPK (100%). PAS stain showed weak to faint pink staining of Pythium filaments in 7 out of 18 cases (38.9%).

CONCLUSION

IKI-H₂SO₄ stain followed by KOH ​+ ​CFW stain detects Pythium filaments most accurately in corneal scraping samples from keratitis patients, although the differences were not statistically significant. The positivity of the stains depends on astute observation by an experienced ocular microbiologist and pathologist.

Spectrum of Mucormycosis Before and During COVID-19: Epidemiology, Diagnosis, and Current Therapeutic Interventions

Purpose of Review

More than half a billion people have been infected and 6.2 million killed by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) since the start of the pandemic in 2019. Systemic glucocorticoids are a double-edged sword, on the one hand, life-saving in treating COVID-19 complications while on the other hand, potentially leading to life-and-limb-threatening opportunistic fungal infections. Mucormycosis (MM) is caused by the mucormycetes family. Although rare, it is characterized by high mortality and significant morbidity. The gross similarities observed with other fungal infections which respond to different treatment regimens have made it all the more imperative to quickly and sensitively diagnose and treat MM. This review discusses the epidemiology of MM before and during the COVID-19 pandemic, associated risk factors, COVID-19-associated MM, diagnosis, and current therapeutic interventions.

Recent Findings

There has been a widespread and worrisome trend of rising in cases of MM, worldwide, but more so in the Indian subcontinent, where it is nicknamed the “black fungus.” This upsurge has picked up the pace ever since the start of the COVID-19 pandemic. Necrosis is secondary to the angio-invasive and pro-thrombotic nature of the mold resulting in extensive lesions presenting mostly as rhino-orbital MM (ROM) and rhino-orbito-cerebral MM (ROCM). Infection is mostly observed in subjects with underlying risk factors such as uncontrolled diabetes, those receiving hematopoietic stem cell transplant, and/or on corticosteroid or immunosuppressive therapy, although it is widely suspected that other factors such as iron and zinc may play a role in the pathogenesis of MM. The “One world one guideline” strategy advocates both prophylactic anti-fungal therapy along with aggressive, prompt, and individualized treatment with anti-fungal drugs such as amphotericin B in addition to vigorous surgical intervention. High-risk groups need particularly rapid diagnosis although empirical anti-fungal therapy may not be delayed. Speeding diagnostic turnaround times are essential to institute early therapy, and there is much scope for newer modalities such as PCR, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and whole-genome sequencing in such endeavors. The results of strict monitoring of blood glucose levels along with rational and limited use of steroids and immunomodulatory drugs have proven to be a significant preventive measure.

Summary

The significant rise in cases of MM worldwide has necessitated viewing each case with a strong index of suspicion. Adoption of rapid diagnostics, early antifungal therapy, and prompt surgical interventions are essential, while high-risk groups need particular focused care which may include prophylactic anti-fungal therapy, limited steroid use, and meticulous control of the underlying disease. Developing quicker and more sensitive diagnostic modalities has great potential to improve the detection and management of MM.

A Rare Case of Pulmonary and Gastrointestinal Mucormycosis Due to Rhizopus spp. in a Child with Chronic Granulomatous Disease

Mucormycosis is a rare but serious fungal infection caused by a mold family known as the Mucorales. These fungi exist throughout the environment, especially in the soil, leaves, compost piles, or decaying woods. Humans contract mucormycosis by coming in contact with the spores from fungus either by inhalation or through cuts on the skin. The population at risk for this life-threatening infection includes diabetes mellitus patients, cancer patients, premature infants, burn patients, and immunocompromised patients. The fungi that most commonly cause mucormycosis are the Rhizopus species, and the least represented are Apophysomyces species. Common clinical manifestations of mucormycosis include pulmonary, cutaneous, rhinocerebral, and gastrointestinal mucormycosis. Cases of lung mucormycosis are often misdiagnosed because of non-specific clinical symptoms and radiological features, and in many cases, have been diagnosed as aspergillosis due to similarities in signs, symptoms, and imaging presentation of the lungs. We present a pediatric case of a 6-year-old from Togo who presented to our hospital in Nigeria with dyspnea, fever, and abdominal pain of five-day duration. The child’s symptoms began 6-months prior, with dry cough, fever, fatigue, and chest pain and abdominal pain. The hospital in Togo where he lived suspected infection with tuberculosis (TB) despite a false-positive Mantoux test and negative chest X-ray. He was initially treated for TB with Isoniazid and vitamin B6 and was discharged home. Six months later, his symptoms have not improved, but became more severe with high grade fever 40 °C (oral reading), anorexia, fatigue, tachypnea, abdominal distention, and cough. The patient was immediately referred to our hospital in Abuja, Nigeria where more specific tests were ordered. He was eventually diagnosed with chronic granulomatous disease induced pulmonary and gastrointestinal (GI) mucormycosis due to Rhizopus spp. In this report, we discuss an unusual clinical presentation of an infection caused by Rhizopus spp., its management, and outcomes in a child with chronic granulomatous disease (CGD).

COVID-19-Associated Mucormycosis: A Matter of Concern Amid the SARS-CoV-2 Pandemic

Mucormycosis is an invasive fungal infection caused by fungi belonging to order Mucorales. Recently, with the increase in COVID-19 infections, mucormycosis infections have become a matter of concern globally, because of the high morbidity and mortality rates associated with them. Due to the association of mucormycosis with COVID-19 disease, it has been termed COVID-19-associated mucormycosis (CAM). In the present review, we focus on mucormycosis incidence, pathophysiology, risk factors, immune dysfunction, interactions of Mucorales with endothelial cells, and the possible role of iron in Mucorales growth. We review the limitations associated with current diagnostic procedures and the requirement for more specific, cost-effective, convenient, and sensitive assays, such as PCR-based assays and monoclonal antibody-based assays for the effective diagnosis of mucormycosis. We discuss the current treatment options involving antifungal drug therapies, adjunctive therapy, surgical treatment, and their limitations. We also review the importance of nutraceuticals-based therapy for the prevention as well as treatment of mucormycosis. Our review also highlights the need to explore the potential of novel immunotherapeutics, which include antibody-based therapy, cytokine-based therapy, and combination/synergistic antifungal therapy, as treatment options for mucormycosis. In summary, this review provides a complete overview of COVID-19-associated mucormycosis, addressing the current research gaps and future developments required in the field.

Rhizomucor pusillus Infection in a Patient with Acute Myeloid Leukaemia After Haematopoietic Stem Cell Transplantation: Clinical Impact of Metagenomics Next-Generation Sequencing

Long-term chemotherapy and immunosuppressants in acute myeloid leukaemia (AML) patients can result in a high risk of opportunistic infections. Rhizomucor pusillus is an opportunistic pathogen that exists in nature, but infection caused by R. pusillus is rare in the clinic. Notably, the sensitivity and detection time of conventional diagnostic tools for this fungus usually falls short of the needs of clinical diagnosis, resulting in treatment failure. Currently, metagenomics next-generation sequencing (mNGS) has played an important role in the detection of pathogens. Here, we report a case of R. pusillus pneumonia in a haematopoietic stem cell transplantation (HSCT) patient, detected by the mNGS method.

Development of a Monoclonal Antibody and a Serodiagnostic Lateral-Flow Device Specific to Rhizopus arrhizus (Syn. R. oryzae), the Principal Global Agent of Mucormycosis in Humans

Mucormycosis is a highly aggressive angio-invasive disease of humans caused by fungi in the zygomycete order, Mucorales. Though a number of different species can cause mucormycosis, the principal agent of the disease worldwide is Rhizopus arrhizus, which accounts for the majority of rhino-orbital-cerebral, pulmonary, and disseminated infections in immunocompromised individuals. It is also the main cause of life-threatening infections in patients with poorly controlled diabetes mellitus, and in corticosteroid-treated patients with SARS-CoV-2 infection, where it causes the newly described disease, COVID-19-associated mucormycosis (CAM). Diagnosis currently relies on non-specific CT, a lengthy and insensitive culture from invasive biopsy, and a time-consuming histopathology of tissue samples. At present, there are no rapid antigen tests for the disease that detect biomarkers of infection, and which allow point-of-care diagnosis. Here, we report the development of an IgG1 monoclonal antibody (mAb), KC9, which is specific to Rhizopus arrhizus var. arrhizus (syn. Rhizopus oryzae) and Rhizopus arrhizus var. delemar (Rhizopus delemar), and which binds to a 15 kDa extracellular polysaccharide (EPS) antigen secreted during hyphal growth of the pathogen. Using the mAb, we have developed a competitive lateral-flow device (LFD) that allows rapid (30 min) and sensitive (~50 ng/mL running buffer) detection of the EPS biomarker, and which is compatible with human serum (limit of detection of ~500 ng/mL) and bronchoalveolar lavage fluid (limit of detection of ~100 ng/mL). The LFD, therefore, provides a potential novel opportunity for the non-invasive detection of mucormycosis caused by Rhizopus arrhizus.

Immunopathology of COVID-19 and its implications in the development of rhino-orbital-cerebral mucormycosis: a major review

PURPOSE

To present a literature review on various immunopathologic dysfunctions following COVID-19 infection and their potential implications in development of rhino-orbital-cerebral mucormycosis (ROCM).

METHODS

A literature search was performed via Google Scholar and PubMed with subsequent review of the accompanying references. Analogies were drawn between the immune and physiologic deviations caused by COVID-19 and the tendency of the same to predispose to ROCM.

RESULTS

Sixty-two articles were reviewed. SARS-CoV-2 virus infection leads to disruption of epithelial integrity in the respiratory passages, which may be a potential entry point for the ubiquitous Mucorales to become invasive. COVID-19 related GRP78 protein upregulation may aid in spore germination and hyphal invasion by Mucorales. COVID-19 causes interference in macrophage functioning by direct infection, a tendency for hyperglycemia, and creation of neutrophil extracellular traps. This affects innate immunity against Mucorales. Thrombocytopenia and reduction in the number of natural killer (NK) cells and infected dendritic cells is seen in COVID-19. This reduces the host immune response to pathogenic invasion by Mucorales. Cytokines released in COVID-19 cause mitochondrial dysfunction and accumulation of reactive oxygen species, which cause oxidative damage to the leucocytes. Hyperferritinemia also occurs in COVID-19 resulting in suppression of the hematopoietic proliferation of B- and T-lymphocytes.

CONCLUSIONS

COVID-19 has a role in the occurrence of ROCM due to its effects at the entry point of the fungus in the respiratory mucosa, effects of the innate immune system, creation of an environment of iron overload, propagation of hyperglycemia, and effects on the adaptive immune system.

Pediatric intussusception due to basidiobolomycosis: a case report and literature review

Background

Pediatric gastrointestinal basidiobolomycosis is an unusual fungal infection caused by Basidiobolus ranarum, an environmental saprophyte found worldwide. Typically, basidiobolomycosis presents as a subcutaneous infection or soft tissue tumor-like lesion, and rarely involves the gastrointestinal tract. Gastrointestinal basidiobolomycosis is most common in young infants. It has no definitive clinical presentation, and almost all cases are misdiagnosed during the initial presentation.

Case presentation

We report the case of a 4-year-old Saudi boy who presented to the emergency department with abdominal pain, nausea, vomiting, and weight loss. Ultrasonography revealed a target sign. Based on the ultrasonography findings, surgery was performed, which revealed the presence of intussusception. Eventually, the patient was diagnosed with intussusception secondary to intra-abdominal basidiobolomycosis based on the histological findings. The patient was readmitted and intravenous voriconazole therapy was initiated. One week after the second admission, the patient developed abdominal pain, nausea, vomiting, inability to hold down food, and constipation. Computed tomography of the abdomen was suggestive of small bowel obstruction, which was managed conservatively. The patient responded well and was subsequently discharged with a prescription of oral voriconazole.

Conclusions

This case reveals that gastrointestinal basidiobolomycosis can cause intussusception. This report will inform clinicians of the importance of considering gastrointestinal basidiobolomycosis in the differential diagnosis of chronic abdominal pain in children, even in the absence of fever or a clinically obvious abdominal mass, especially in countries such as Saudi Arabia, where cases have been reported.

Mini Review: Risk Assessment, Clinical Manifestation, Prediction, and Prognosis of Mucormycosis: Implications for Pathogen- and Human-Derived Biomarkers

Mucormycosis is a fungal disease caused by members of the fungal order Mucorales, which are abundantly found in terrestrial environments. The fungi propagate clonally via mitospores, which are transmitted to humans through the air and cause superficial or invasive infections. The disease has emerged in recent years and coincides generally with immunosuppression on the patient side. Mucormycosis is still rarely recognized in the clinical because of its unspecific symptoms which often triggers misdiagnosis with bacterial or viral infections leading to prolonged therapeutic cycles and loss of valuable time to manage mucormycosis properly. Infected patients develop various clinical forms, most notably ranging from rhinocerebral via pulmonary to gastrointestinal forms. Traditional diagnosis is based on culture and histopathologic examinations of the affected tissue. But, the achievement of a precise result is time-consuming, labor-intensive, requires mycological expertise and the finding appears often too late. A rapid and precise diagnosis is mandatory because symptoms are non-specific and the disease is rapidly progressing with often fatal outcome. Mucormycosis was increasingly associated with other infections and underlying conditions and risk factors causing comorbidities, which are difficult to successfully manage. This mini-review summarizes the current knowledge on the epidemiology and causative agents of mucormycosis, transmission, risk factors, clinical presentation, diagnosis, and highlights the lack of appropriate biomarkers on the pathogen and the host sides for rapid pathogen and host susceptibility detection, respectively. Fungal antigens and single nucleotide polymorphisms (SNPs) in human host genes are useful for the assessment of susceptibility. This mini-review addresses possibilities for early prediction of susceptibility to mucormycosis based on forecasting of the risk of infection with fungal pathogens other than Mucorales. The topic of early prediction and diagnosis of mucormycosis represents a current research gap and highlights the importance of potential future developments in the area of risk assessment, susceptibility prognosis in conjunction with early diagnosis to reduce mortality in patients suffering from mucormycosis.

Cluster analysis and network visualization of research in mucormycosis: a scientometric mapping of the global publications from 2011 to 2020

Purpose

Mucormycosis has evolved as a post-COVID-19 complication globally, especially in India. The research on fungus has been very primitive, and many scientific publications have been discovered. The current COVID-19 pandemic needs further investigation into this unusual fungal infection. This review study aims to provide a pen-picture to researchers, science policymakers and scientists about different bibliometric indicators related to the research literature on mucormycosis.

Design/methodology/approach

The quantitative research was conducted using the established procedure of bibliometric investigation on data collected from Scopus from 2011 to 2020 using a validated search query. The search query consisted of keywords “Mucormycosis” or “Mucormycoses” or “Mucormycose” or “Mucorales Infection” or “Mucorales Infections” or “Black Fungus Infection” or “Black Fungus Infections” or “Zygomycosis” in the “Title-Keyword-Abstract” search option for data extraction. The analysis of data is performed using MS-Excel. Mapping was done with state-of-the-art visualization tools Biblioshiny and VOSviewer, using bibliometric indicators as units of analysis.

Findings

The analysis reveals that the first publication on this topic was reported from 1923 onwards. In total, 9,423 authors contributed 1,896 papers with 11,437 collaborated authors, documents per author are 0.201, authors per document are 4.97 and co-authors per document are 6.03. Total records were published in 779 journals in the English language from 75 countries globally. Mucormycosis literature is mostly open access, with 1,210 publications available via different open access routes. The highest number of articles (204) published in the journal “Mycoses” with 1,333 authors received 4,875 cited references, and the h-index has 24. The growth of publications is exponential, as depicted by the Price Law. The USA has recorded a maximum number of publications at both country and institutional levels compared to the other nations. There has been extensive research on mucormycosis before the outbreak as a post-COVID complication, as indicated by the highest number of publications in 2019.

Practical implications

The research hot spots have altered from “Mucormycosis,” “fungi,” “Zygomycosis” and “Drug efficacy”, “Drug Safety” to “Microbiology,” “Pathology,” “nucleotide sequence,” “surgical debridement” which indicates that potential area of research in the near future will be concerned with more extensive research in mucormycosis to develop standard treatment procedures to fight this infection. The quantity of scientific publications has also increased over time. The research and health community are called upon to join forces to activate existing knowledge, generate new insights and develop decision-supporting tools for health authorities in different nations to leverage vaccination in its transformational role toward successfully attaining nil cases of COVID-19.

Originality/value

The analysis of collaboration, findings, the research networks and visualization makes this study novel and separates from traditional metrics analysis. To the best of the authors’ knowledge, this work is original, and no similar studies have been found with the objectives included here.

Two Cases of Post-Traumatic Mucormycosis due to Mucor circinelloides: Salvage Therapy with a Combination of Adjunctive Therapies

Mucormycosis is a rare, emerging angioinvasive infection caused by ubiquitous filamentous fungi. In recent decades, an increase in cutaneous or post-traumatic mucormycosis has been reported. We describe two cases of post-traumatic wound infections with Mucor circinelloides, a mucor species only rarely reported as a cause of post-traumatic mucormycosis. Often considered lethal, management required a combination of medical and surgical therapies to achieve a favorable outcome in both cases.

Combat-Related Invasive Fungal Wound Infections

INTRODUCTION

During Operation Enduring Freedom in Afghanistan, an outbreak of combat-related invasive fungal wound infections (IFIs) emerged among casualties with dismounted blast trauma and became a priority issue for the Military Health System.

METHODS

In 2011, the Trauma Infectious Disease Outcomes Study (TIDOS) team led the Department of Defense IFI outbreak investigation to describe characteristics of IFIs among combat casualties and provide recommendations related to management of the disease. To support the outbreak investigation, existing IFI definitions and classifications utilized for immunocompromised patients were modified for use in epidemiologic research in a trauma population. Following the conclusion of the outbreak investigation, multiple retrospective analyses using a population of 77 IFI patients (injured during June 2009 to August 2011) were conducted to evaluate IFI epidemiology, wound microbiology, and diagnostics to support refinement of Joint Trauma System (JTS) clinical practice guidelines. Following cessation of combat operations in Afghanistan, the TIDOS database was comprehensively reviewed to identify patients with laboratory evidence of a fungal infection and refine the IFI classification scheme to incorporate timing of laboratory fungal evidence and include categories that denote a high or low level of suspicion for IFI. The refined IFI classification scheme was utilized in a large-scale epidemiologic assessment of casualties injured over a 5.5-year period.

RESULTS

Among 720 combat casualties admitted to participating hospitals (2009-2014) who had histopathology and/or wound cultures collected, 94 (13%) met criteria for an IFI and 61 (8%) were classified as high suspicion of IFI. Risk factors for development of combat-related IFIs include sustaining a dismounted blast injury, experiencing a traumatic transfemoral amputation, and requiring resuscitation with large-volume (>20 units) blood transfusions. Moreover, TIDOS analyses demonstrated the adverse impact of IFIs on wound healing, particularly with order Mucorales. A polymerase chain reaction (PCR)-based assay to identify filamentous fungi and support earlier IFI diagnosis was also assessed using archived formalin-fixed, paraffin-embedded tissue specimens. Although the PCR-based assay had high specificity (99%), there was low sensitivity (63%); however, sensitivity improved to 83% in tissues collected from sites with angioinvasion. Data obtained from the initial IFI outbreak investigation (37 IFI patients) and subsequent TIDOS analyses (77 IFI patients) supported development and refinement of a JTS clinical practice guideline for the management of IFIs in war wounds. Furthermore, a local clinical practice guideline to screen for early tissue-based evidence of IFIs among blast casualties at the Landstuhl Regional Medical Center was critically evaluated through a TIDOS investigation, providing additional clinical practice support. Through a collaboration with the Uniformed Services University Surgical Critical Care Initiative, findings from TIDOS analyses were used to support development of a clinical decision support tool to facilitate early risk stratification.

CONCLUSIONS

Combat-related IFIs are a highly morbid complication following severe blast trauma and remain a threat for future modern warfare. Our findings have supported JTS clinical recommendations, refined IFI classification, and confirmed the utility of PCR-based assays as a complement to histopathology and/or culture to promote early diagnosis. Analyses underway or planned will add to the knowledge base of IFI epidemiology, diagnostics, prevention, and management.

Novel 2-aryl-4-aryloxyquinoline-based fungistatics for Mucor circinelloides. Biological evaluation of activity, QSAR and docking study

Zygomycetes are ubiquitous saprophytes in natural environments which transform organic matter. Some zygomycetes of gender Mucor have attracted interest in health sector. Due to its ability as opportunistic microorganisms infecting immuno-compromised people and to the few available pharmacological treatments, the mucormycosis is receiving worldwide attention. Concerning to the pharmacological treatments, some triazole-based compounds such as fluconazole are extensively used. Nevertheless, we focused in the quinolines since they are broadly used models for the design and development of new synthetic antifungal agents. In this study, the fungistatic activity on M. circinelloides of various 2-aryl-4-aryloxyquinoline-based compounds was discovered, and in some cases, it resulted better than reference compound fluconazole. These quinoline derivatives were synthesized via the C_sp²-O bond formation using diaryliodonium(III) salts chemistry. A QSAR study was carried out to quantitatively correlate the chemical structure of the tested compounds with their biological activity. Also, a docking study to identify a plausible action target of our more active quinolines was carried out. The results highlighted an increased activity with the fluorine- and nitro-containing derivatives. In light of the few mucormycosis pharmacological treatments, herein we present some non-described molecules with excellent in vitro activities and potential use in the mucormycosis treatment.