Mucormycosis: Pathogenesis and Pathology

Mucormycosis in an Immunocompetent Patient Recovering From Dengue Fever

Mucormycosis is a rare yet aggressive fungal infection. Despite its rarity, India has experienced a surge in cases during the post-COVID-19 era. The high mortality rate associated with this infection necessitates early diagnosis, intervention, and aggressive treatment. Typically, it is observed in immunocompromised patients, where the disease progresses rapidly and leads to unfavorable outcomes. However, occurrences in previously healthy individuals are not uncommon. Dengue has been occasionally associated with mucormycosis in the post-recovery phase. This case report highlights the importance of heightened clinical suspicion and early intervention in patients with recent dengue infections and chronic sinus conditions. It explores potential risk factors, such as dengue-related immune alterations, environmental exposures, and anatomical alterations that may contribute to the development of mucormycosis in otherwise healthy individuals.

Mucormycosis: A Rare disease to Notifiable Disease

Mucormycosis is the third most frequent invasive mycosis, following candidiasis and aspergillosis. It is frequently neglected due to its rare occurrence; but recently attend the status of notifiable disease due to its higher incidence in both developed and developing nations. India has received global notice since its estimated instances were greater than the global estimated figures. Mucormycosis has several clinical manifestations, including rhino-orbital-cerebral (ROCM), pulmonary, gastrointestinal, cutaneous, renal, and diffuse Mucormycosis. ROCM is the most frequent clinical manifestation in India, although pulmonary mucormycosis is prevalent worldwide. This review also discusses host defenses, pre disposing risk factors and fungal virulence factors that impair host's ability to prevent fungus invasion and disease establishment. The diagnosis of the disease depends on clinical interventions, histological or microbiological procedures along with molecular methods to obtain timely results. But there are still unmet challenges for rapid diagnosis of the disease. Treatment of the disease is achieved by multimodal approaches such as reversal of underlying predisposing factors, rapid administration of antifungals in optimal doses and surgical procedures to remove infected tissues. Liposomal Amphotericin B, Posaconazole and Isavuconazoles are preferred as the first line of treatment procedures. clinical trials. Different studies have improved the existing drug and under clinical trials while several studies predicted the new potential targets as CotH and Ftr1 as shown in infection and in vitro models. Therefore, current scenario demands a multidisciplinary approach is needed to investigate the prevalence, pathogenesis which is highly important for the advancement of rapid diagnosis and effective treatment.

Virulence traits and novel drug delivery strategies for mucormycosis post-COVID-19: a comprehensive review

The outbreak of a fatal black fungus infection after the resurgence of the cadaverous COVID-19 has exhorted scientists worldwide to develop a nutshell by repurposing or designing new formulations to address the crisis. Patients expressing COVID-19 are more susceptible to Mucormycosis (MCR) and thus fall easy prey to decease accounting for this global threat. Their mortality rates range around 32-70% depending on the organs affected and grow even higher despite the treatment. The many contemporary recommendations strongly advise using liposomal amphotericin B and surgery as first-line therapy whenever practicable. MCR is a dangerous infection that requires an antifungal drug administration on appropriate prescription, typically one of the following: Amphotericin B, Posaconazole, or Isavuconazole since the fungi that cause MCR are resistant to other medications like fluconazole, voriconazole, and echinocandins. Amphotericin B and Posaconazole are administered through veins (intravenously), and isavuconazole by mouth (orally). From last several years so many compounds are developed against invasive fungal disease but only few of them are able to induce effective treatment against the micorals. Adjuvant medicines, more particularly, are difficult to assess without prospective randomized controlled investigations, which are challenging to conduct given the lower incidence and higher mortality from Mucormycosis. The present analysis provides insight into pathogenesis, epidemiology, clinical manifestations, underlying fungal virulence, and growth mechanisms. In addition, current therapy for MCR in Post Covid-19 individuals includes conventional and novel nano-based advanced management systems for procuring against deadly fungal infection. The study urges involving nanomedicine to prevent fungal growth at the commencement of infection, delay the progression, and mitigate fatality risk.

Emergence of Rhino-Orbito-Cerebral Mucormycosis in Peru: Impact of the COVID-19 Pandemic

Introduction Mucormycosis is an invasive fungal infection caused by Mucorales that has been increasingly recognized over the years, particularly during the COVID-19 pandemic. Nevertheless, in Peru, there has been limited research on this disease. This study seeks to provide insights into the demographics, clinical presentations, treatment, and outcomes of patients with mucormycosis, before and during the COVID-19 pandemic. Materials and methods We conducted a retrospective case series by reviewing the medical records of Peruvian patients hospitalized at a referral medical center between 2017 and 2021. The selection criteria included patients aged 18 years or older with clinical features of rhino-orbito-cerebral mucormycosis supported by radiological imaging. We extracted data related to risk factors for mucormycosis infection, clinical presentation, management, and hospitalization. Data analysis was performed using Stata software (StataCorp LLC, College Station, Texas, USA) to compare patient groups before and during the COVID-19 pandemic. Results Nineteen cases met our selection criteria: 11 men and eight women with an average age of 57.6 ± 10.6 years. All 19 patients had type 2 diabetes mellitus as comorbidity, with 13 cases exhibiting uncontrolled diabetes. Six patients presented before the COVID-19 pandemic, while 13 during its course. Within the group of patients diagnosed during the pandemic, nine were diagnosed with SARS-CoV-2 infection. Regarding the site of mucormycosis infection, the paranasal sinuses were predominantly involved. Survival analysis indicated that patients who developed mucormycosis during the COVID-19 pandemic, those with uncontrolled diabetes, or those who did not undergo surgery had lower probabilities of survival. Conclusion Mucormycosis is a rare infection associated with high mortality and morbidity with increased frequency during the COVID-19 pandemic. Early diagnosis, timely administration of antifungal treatment, surgery, and effective management of comorbidities can have life-saving implications. Unfortunately, despite the availability of various diagnostic tests and less toxic antifungal options such as liposomal amphotericin-B, such resources are not accessible in Peru's national hospitals.

Analog and Digital Protocols for Functional Prosthetic Rehabilitation of Post-COVID-19 Rhino-Orbito Cerebral Mucormycosis Maxillofacial Defects: A Case Series

The current study aims to present our clinical observations and experience gathered during the diagnosis, clinical presentation, medical/surgical treatment, and functional prosthetic rehabilitation of cases of rhino-orbital/cerebral Mucormycosis patients. Mucormycosis is an aggressive, life-threatening invasive fungal infection that occurs in people who are immune-compromised. The rise of ROCM during the second wave of the COVID-19 pandemic in India suggests a more effective association between Mucormycosis and the SARS-CoV-2 delta variant. The treatment strategy for Mucormycosis is an early diagnosis which is critical for a successful outcome. The initial step is to reduce or remove underlying risk factors followed by surgical excision and debridement of the afflicted tissues supplemented with antifungal medication. The first-line antifungal treatment is Liposomal Amphotericin B. Postsurgical resection defects are rehabilitated by either removable partial prosthesis (obturators) or by fixed zygomatic implant/patient-specific implant supported prosthesis. Management of ROCM requires a multidisciplinary approach. This case series highlights detailed medical, surgical, and functional prosthetic management modalities adopted by our team in managing such a dreaded disease which may be used as a tool for the formulation of standardized prevention and management/treatment/rehabilitation protocols in the future so that disease morbidity and mortality be reduced and an endemic outbreak could be averted.

Mucormycosis in a Patient with Severe COVID-19 Disease—The First Case Report in Romania and a Literature Review

Introduction: COVID-19 infection is often associated with a vast spectrum of opportunistic bacterial and fungal infections. Herein, we share a summary of the first case of COVID-19-associated mucormycosis (CAM) in a patient from Romania. Case presentation: A 51-year-old male non-smoker, with no known relevant medical history, who denied any previous alcohol use and was vaccinated against COVID-19 (complete scheme with Vaxzevria), was admitted to the hospital for severe COVID-19 infection. The first mucormycosis-related symptoms were reported on the eighth day of admission and were followed by the rapid deterioration of the patient’s condition and, consequently, death. The main aggravating factors, which were identified to be associated with the development of mucormycosis and with the poor outcome, were the association of severe COVID-19, new-onset COVID-19-triggered type 2 diabetes, and corticoid treatment for severe COVID-19. Conclusion: The association between severe COVID-19 and newly diagnosed type 2 diabetes, triggered by COVID-19 infection, increases the risk of severe opportunistic fungal infections and the associated mortality rates.

Mucorales and Mucormycosis: Recent Insights and Future Prospects

The classification of Mucorales encompasses a collection of basal fungi that have traditionally demonstrated an aversion to modern genetic manipulation techniques. This aversion led to a scarcity of knowledge regarding their biology compared to other fungal groups. However, the emergence of mucormycosis, a fungal disease caused by Mucorales, has attracted the attention of the clinical field, mainly because available therapies are ineffective for decreasing the fatal outcome associated with the disease. This revitalized curiosity about Mucorales and mucormycosis, also encouraged by the recent COVID-19 pandemic, has spurred a significant and productive effort to uncover their mysteries in recent years. Here, we elaborate on the most remarkable breakthroughs related to the recently discovered genetic advances in Mucorales and mucormycosis. The utilization of a few genetic study models has enabled the identification of virulence factors in Mucorales that were previously described in other pathogens. More notably, recent investigations have identified novel genes and mechanisms controlling the pathogenic potential of Mucorales and their interactions with the host, providing fresh avenues to devise new strategies against mucormycosis. Finally, new study models are allowing virulence studies that were previously hampered in Mucorales, predicting a prolific future for the field.

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.

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.

Clinical case of mucormycosis in patient COVID-19. Case report

The COVID-19 epidemic is being revealed from a new angle every month. In particular, with the appearance of the delta strain, mucormycosis began to manifest in some patients, which had previously been extremely rare. Mucormycosis is a rare, aggressive infection caused by filamentous fungi of the Mucorales family and associated with high morbidity and mortality rates. The main risk factors for the mucormycosis in patients with COVID-19 are diabetes mellitus and diabetic ketoacidosis, uncontrolled hyperglycemia and massive use of glucocorticoids, vascular damage, thrombosis, lymphopenia, which often occur against the background of COVID-19 and make a person vulnerable to secondary or opportunistic fungal infection. We present a clinical case of mucormycosis in a 21-year-old female patient with COVID-19-associated severe pneumonia and concomitant type I diabetes mellitus. The patient was hospitalized and received standard therapy during inpatient treatment, including glucocorticosteroids in accordance with the severity of the course of COVID-19. On the 12th day from the hospitalization, the patient's condition deteriorated significantly, and the visible changes in the skin and soft tissues of the face, characteristic of mucormycosis appeared. Despite the drug therapy correction, the patient died because of the acute respiratory failure in combination with septic fungal damage of the brain stem.

Epidemiology, clinical features, therapeutic interventions and outcomes of mucormycosis in Shiraz: an 8-year retrospective case study with comparison between children and adults

Mucormycosis is an invasive fungal infection with high morbidity and mortality rate despite the early diagnosis and proper therapeutic interventions. Given the importance of epidemiological data in reviewing the attitude toward infectious diseases in developing countries, the current retrospective case study aimed to compare the epidemiological aspects, risk factors, clinical characteristics, therapeutic interventions, and outcomes of mucormycosis between adults and children during eight years (2013-2021) in the main infectious disease referral centers in the southwest of Iran. The median age of 164 patients included in this study was 47 years (IQR 22-59). The median length of hospitalization was 33 days.The annual incidence of mucormycosis-related hospitalizations was estimated 1.76 per 10,000 admissions during the study period. Moreover, the incidence of infection was 2.4 times higher in males than females in children. Diabetes mellitus was the most frequent predisposing factor in adults (46.0%). The main risk factor in children was hematologic malignancy (52.6%), but a considerable proportion of them (28.9%) were immunocompetent.The most frequent antifungal agent used was liposomal amphotericin B (82.3%) as monotherapy. The combination therapy was used more in adults (15.8%) than children (7.9%). In addition, surgical intervention with antifungal therapy was considered the most effective therapeutic approach. The in-hospital mortality rate was 14.6% for adults, whereas it was zero for children. Our findings provide a recent epidemiologic analysis of mucormycosis among hospitalized patients in both children and adults. Mucormycosis mainly affects individuals with diabetes mellitus or hematological malignancies and presents as rhino-orbito-cerebral form. Proven diagnosis of mucormycosis according to clinical manifestations and histopathology observations accompanied by proper antifungal treatments may improve survival rates.

Deadly Fungi: Invasive Fungal Rhinosinusitis in the Head and Neck

Invasive fungal rhinosinusitis (IFRS) is a serious infection that is associated with high morbidity and mortality rates. The incidence of IFRS has been increasing, mainly because of the increased use of antibiotics and immunosuppressive drugs. Rhino-orbital cerebral mucormycosis has recently reemerged among patients affected by COVID-19 and has become a global concern. The detection of extrasinus involvement in its early stage contributes to improved outcomes; therefore, imaging studies are essential in establishing the degree of involvement and managing the treatment properly, especially in immunocompromised patients. The common sites of extrasinus fungal invasion are the intraorbital, cavernous sinus, and intracranial regions. Fungi spread directly to these regions along the blood vessels or nerves, causing devastating complications such as optic nerve ischemia or compression, optic neuritis or perineuritis, orbital cellulitis, cavernous sinus thrombosis, mycotic aneurysm, vasculitis, internal carotid arterial occlusion, cerebral infarction, cerebritis, and brain abscess. IFRS has a broad imaging spectrum, and familiarity with intra- and extrasinonasal imaging features, such as loss of contrast enhancement of the affected region, which indicates tissue ischemia due to angioinvasion of fungi, and the surrounding anatomy is essential for prompt diagnosis and management. The authors summarize the epidemiology, etiology, risk factors, and complications of IFRS and review the anatomy and key diagnostic imaging features of IFRS beyond the sinonasal regions. ^©RSNA, 2022.

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.

Does Long-term Oxygen Therapy and Noninvasive Ventilation Predispose Rhino-orbital-cerebral Mucormycosis in COVID-19 Patients?

How to cite this article: Kumar A, Kumar A, Kumar N, Kumar A, Sinha C, Singh PK. Does Long-term Oxygen Therapy and Noninvasive Ventilation Predispose Rhino-orbital-cerebral Mucormycosis in COVID-19 Patients? Indian J Crit Care Med 2022;26(9):1063-1064.

Diagnosis and management of mucormycosis in the dental clinic: A guide for oral health professionals in India

With the current pandemic raging over the world, science and medicine is faced with hereto with unfought enemies or less fought opponent in the form of viruses and consequently, other biotic entities. While researchers are striving to identify and conquer the variants of COVID-19, other innocuous organisms are raising their ugly heads in the form of opportunistic fungal infections. Mucormycosis/Black Fungus is an invasive opportunistic fungal infection caused by mucorale species. It spreads through blood vessels causing thrombosis, ischemia, and necrosis. Population with pre-existing immunocompromised conditions such as Diabetes Mellitus, Malignancy, Long-term immunosuppressant therapy are more susceptible. Mucormycosis associated with Corona Virus Disease-2019 (COVID-19) proved to be catastrophic due to its high mortality rates. Rhino orbital Mucormycosis is the most common form. The primary care physician, being the first and often, (more so in developing countries) and being the only point of contact with a healthcare professional, plays a pivotal role in the diagnosis and management of this condition. The keystone to decreasing mortality is early detection and diagnosis followed by preventive measures to control progression to the brain. A multidisciplinary approach by various specialties is a prerequisite for effective diagnosis and management. Antifungal therapy, surgical debridement, and resection of the affected areas are protocols to be followed. Post-operative defects cause impairment of function, phonetics, and esthetics. Prosthetic rehabilitation of these defects has shown favorable results, especially in the aged and immunocompromised individuals.

Mucormycosis and COVID-19-Associated Mucormycosis: Insights of a Deadly but Neglected Mycosis

The ongoing COVID-19 pandemic has quickly become a health threat worldwide, with high mortality and morbidity among patients with comorbidities. This viral infection promotes the perfect setting in patients for the development of opportunistic infections, such as those caused by fungi. Mucormycosis, a rare but deadly fungal infection, has recently increased its incidence, especially in endemic areas, since the onset of the pandemic. COVID-19-associated mucormycosis is an important complication of the pandemic because it is a mycosis hard to diagnose and treat, causing concern among COVID-19-infected patients and even in the already recovered population. The risk factors for the development of mucormycosis in these patients are related to the damage caused by the SARS-CoV-2 itself, the patient's overstimulated immune response, and the therapy used to treat COVID-19, causing alterations such as hyperglycemia, acidosis, endothelial and lung damage, and immunosuppression. In this review, the molecular aspects of mucormycosis and the main risk factors for the development of COVID-19-associated mucormycosis are explained to understand this virus-fungi-host interaction and highlight the importance of this neglected mycosis.

A Vaccine Construction against COVID-19-Associated Mucormycosis Contrived with Immunoinformatics-Based Scavenging of Potential Mucoralean Epitopes

Mucormycosis is a group of infections, caused by multiple fungal species, which affect many human organs and is lethal in immunocompromised patients. During the COVID-19 pandemic, the current wave of mucormycosis is a challenge to medical professionals as its effects are multiplied because of the severity of COVID-19 infection. The variant of concern, Omicron, has been linked to fatal mucormycosis infections in the US and Asia. Consequently, current postdiagnostic treatments of mucormycosis have been rendered unsatisfactory. In this hour of need, a preinfection cure is needed that may prevent lethal infections in immunocompromised individuals. This study proposes a potential vaccine construct targeting mucor and rhizopus species responsible for mucormycosis infections, providing immunoprotection to immunocompromised patients. The vaccine construct, with an antigenicity score of 0.75 covering, on average, 92-98% of the world population, was designed using an immunoinformatics approach. Molecular interactions with major histocompatibility complex-1 (MHC-I), Toll-like receptors-2 (TLR2), and glucose-regulated protein 78 (GRP78), with scores of -896.0, -948.4, and -925.0, respectively, demonstrated its potential to bind with the human immune receptors. It elicited a strong predicted innate and adaptive immune response in the form of helper T (Th) cells, cytotoxic T (TC) cells, B cells, natural killer (NK) cells, and macrophages. The vaccine cloned in the pBR322 vector showed positive amplification, further solidifying its stability and potential. The proposed construct holds a promising approach as the first step towards an antimucormycosis vaccine and may contribute to minimizing postdiagnostic burdens and failures.

The cross-talk between mucormycosis, steroids and diabetes mellitus amidst the global contagion of COVID-19

Mucormycosis is an opportunistic fungal disease that targets individuals having an impaired immune system due to a wide array of risk factors including HIV-AIDS, immunosuppressive therapy, diabetes mellitus, etc. The current explosive outbreak of coronavirus disease 2019 (COVID-19) has become the latest threat to such patients who are already susceptible to secondary infections. Physiological outcomes of COVID-19 end up in a cascade of grave alterations to the immunological profile and irreparable harm to their respiratory passage, heart and kidneys. Corticosteroidal treatment facilitates faster recovery and alleviates the adverse pathological effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). But clinical reports lend this approach a darker perspective especially if these patients have pre-existing diabetes mellitus. The mucormycotic fungal genera belonging to the order Mucorales not only survive but thrive under the comorbidity of COVID-19 and diabetes, often staying undetected until they have inflicted irreversible damage. Steroidal usage has been noted to be a common thread in the sudden spurt in secondary fungal infections among COVID-19 cases. Once considered a rare occurrence, mucormycosis has now acquired a notoriously lethal status in mainstream medical hierarchy. We set out to investigate whether corticosteroidal therapy against COVID-19 emboldens the development of mucormycosis. We also assess the conditions brought forth by steroidal usage and uncontrolled progression of diabetes in COVID-19 cases and their effect on the susceptibility towards mucormycosis.

A clinico-pathological study of COVID-19 associated rhino-orbital-cerebral mucormycosis

Purpose

Known predisposing factors for mucormycosis are neutropenia and diabetes. Though COVID-19 is associated with hyperinflammatory response, a high surge in rhino-orbital-cerebral mucormycosis (ROCM) cases was observed during the second wave. The histopathological features reflect the background pathogenesis. This study analyzes the histopathological features and clinical presentation of COVID-19-associated ROCM.

Methods

In this retrospective observational study, the clinical details of 89 proven ROCM patients treated during May-July 2021 were collected from the case records. Histopathological features were correlated with clinical staging groups and outcomes. The mean neutrophil-to-lymphocyte ratio (NLR) of clinical and outcome groups were compared.

Results

The mean age was 54.71 ± 11.03 years, with male patients constituting a majority (78.7%). Uncontrolled diabetes mellitus was noted in 70.8% of patients, and 3.4% had normal range of blood sugar. The mean blood sugar was 298.08 ± 99.51 mg/dL. The mean duration of onset of symptoms of mucormycosis from the diagnosis of COVID-19 was 17.36 ± 7.392 (3-45) days. Poor outcome with disease progression or death occurred in 21.3% of patients. Clinical group II patients (44.9%) with ROCM stages 3c and above had poor outcomes (P = 0.005). Histopathological analysis showed minimal inflammation in 25.8%, neutrophil extracellular trap (NET) in 75.3%, and angio-invasion in 28.1% of patients. Minimal inflammation was associated with clinical group II (P = 0.004) and poor outcome (P = 0.001). Angio-invasion correlated with poor outcome (P = 0.007). Patients with severe clinical group and poor outcome had higher mean NLR with P = 0.017 and P = 0.007, respectively.

Conclusion

Vision loss and cerebral involvement had poor outcomes. The histopathologic features such as inflammation and angio-invasion along with NLR aid as prognostic indicators in the management of ROCM. The role of NET in the pathogenesis of COVID-19-associated ROCM needs further studies.

Mucormycosis of the Spine: A Case Report and Review of the Literature

Mucormycosis is an extremely rare, invasive infection commonly isolated to patients with known immunosuppressed status. In the present case, a 36-year-old woman, with a history of T-cell acute lymphoblastic leukemia in remission, presented with T4 osteomyelitis and an associated epidural collection. Biopsy was consistent with mucormycosis, and the patient was recommended for surgical debridement. After declining debridement, the patient was successfully managed on a multiagent antifungal regimen consisting of intravenous amphotericin B, micafungin, and oral posaconazole. The patient was alive without clear evidence of disease at eight months, representing one of the first cases of spinal mucormycosis infection successfully treated with medical management alone. We additionally review the previous descriptions of spinal mucormycosis infections to identify those interventions most associated with successful clearance or containment of these infections.

Mucormycosis Amid COVID-19 Crisis: Pathogenesis, Diagnosis, and Novel Treatment Strategies to Combat the Spread

The havoc unleashed by COVID-19 pandemic has paved way for secondary ominous fungal infections like Mucormycosis. It is caused by a class of opportunistic pathogens from the order Mucorales. Fatality rates due to this contagious infection are extremely high. Numerous clinical manifestations result in damage to multiple organs subject to the patient's underlying condition. Lack of a proper detection method and reliable treatment has made the management of this infection troublesome. Several reports studying the behavior pattern of Mucorales inside the host by modulation of its defense mechanisms have helped in understanding the pathogenesis of this angio-invasive infection. Many recent advances in diagnosis and treatment of this fungal infection have not been much beneficial. Therefore, there is a need to foster more viable strategies. This article summarizes current and imminent approaches that could aid effective management of these secondary infections in these times of global pandemic. It is foreseen that the development of newer antifungal drugs, antimicrobial peptides, and nanotechnology-based approaches for drug delivery would help combat this infection and curb its spread.

Storm of a rare opportunistic life threatening mucormycosis among post COVID-19 patients: A tale of two pathogens

Mucormycosis is a rare but life-threatening opportunistic fungal infection caused by a group of molds that belong to Zygomycetes of the order Mucorales. These fungi are found in the environment such as soil, decaying vegetation, and organic matters. Sporangiospores present in the environment enter the human body through inhalation or direct skin inoculation by trauma or ingestion and result in pulmonary, cutaneous, and gastrointestinal mucormycosis, respectively, in immunocompromised hosts. Patients with uncontrolled diabetes, hematological malignancies, high-dose glucocorticoid therapy, iron overload, and organ transplantation are at high risk of acquiring mucormycosis. The second wave of severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] affected India severely with the highest number of cases and deaths compared to all other countries. Additionally, the country was affected by emergence of rare but life-threatening mucormycosis. Currently, many coronavirus disease 2019 patients with underlying risk factors such as uncontrolled diabetes, high-dose steroid therapy, and exposure to mechanical ventilation have developed mucormycosis. Inhalation is the most common mode of transmission that results in colonization of sporangiospores in the nose. In immunocompromised host, sporangiospores germinate, and subsequently form hyphae. These hyphae invade into tissues, and produce tissue infarction, necrosis, and thrombosis. Angioinvasion causes hematogenous dissemination to many organs, predominantly to brain, that result in rhino-orbital-cerebral mucormycosis. Clinical characteristics, radio imaging, fungal culture, histopathology, and molecular techniques are the key diagnostic methods. Surgical intervention and aggressive antifungal therapy are the main management strategies. Amphotericin B is the drug of choice for treatment of mucormycosis, whereas posaconazole or isavuconazole is used for step-down therapy and salvage therapy.

Croton cajucara Essential Oil Nanoemulsion and Its Antifungal Activities

The purpose of this study was to develop a stable nanoemulsion (NE) containing Croton cajucara 7-hydroxycalamenene-rich essential oil (NECC) with antifungal activity. The NECCs were prepared using an ultrasonic processor with Pluronic® F-127 as the aqueous phase. In order to evaluate the NECCs, the droplet size, polydispersity index (PdI), percentage of emulsification, and pH were determined along with a stability study. The NECC selected for the study had 15% surfactant, showed 100% emulsification, Pdl of 0.249, neutral pH, droplet diameters of about 40 nm, and remained stable over 150 days at room temperature. In addition, the NECC activity against some species of Zygomycetes and Candida, as well as the potential to inhibit fungal extracellular proteases, were assessed, and, finally, the hemolytic activity was evaluated. The best NECC antifungal activities were against Mucorramosissimus (Minimal inhibitory concentration (MIC) = 12.2 μg/mL) and Candida albicans (MIC = 25.6 μg/mL). The highest extracellular protease activities of M. ramosissimus and C. albicans were detected at pH 3 and 4, respectively, which were totally inhibited after NECC treatment. The NECC showed no hemolytic effect at the highest concentration tested (2 mg/mL).

A case report of rhino-facial mucormycosis in a non-diabetic patient with COVID-19: a systematic review of literature and current update

BACKGROUND

COVID-19 disease may be associated with a wide range of bacterial and fungal infections. We report a patient with COVID-19 infection who developed rhino-facial mucormycosis during treatment with corticosteroids.

CASE PRESENTATION

A 59-year-old non-diabetic male patient was admitted with a diagnosis of COVID-19 based on positive RT-PCR and CT of the lungs. Due to sever lung involvement, he was treated with methylprednisolone. The patient was re-admitted to hospital, due to nasal obstruction and left side facial and orbital swelling, several days after discharge. In sinus endoscopic surgery, debridement was performed and the specimens were sent to pathology and mycology laboratories. A nasal biopsy showed wide hyphae without septa. The sequenced PCR product revealed Rhizopus oryzae. Despite all medical and surgical treatment, the patient died. In addition, the characteristics of patients with COVID-19-associated mucormycosis were reviewed in 44 available literatures. In most studies, diabetes mellitus was the most common predisposing factor for mucormycosis.

CONCLUSION

Our report highlights the need for assessing the presence of mucormycosis in patients with COVID-19 and also it shows that physicians should consider the potential for secondary invasive fungal infections in COVID-19 cases.

Rhino-orbital mucormycosis following COVID-19 in previously non-diabetic, immunocompetent patients

PURPOSE

To report a series of 13 immunocompetent patients who developed new-onset uncontrolled diabetes mellitus (DM) following COVID-19 infection and presented as rhino-orbital mucormycosis (ROM).

METHOD

Retrospective study.

RESULTS

A total of 127 patients of COVID-19 Associated Mucormycosis (CAM) were evaluated at four centres in India. All patients underwent endoscopic sinus debridement surgery and received systemic amphotericin-B therapy. Five patients (5/13; 38.4%) received retrobulbar amphotericin-B injections. Orbital exenteration was performed in advanced orbital involvement or progression of orbital disease in spite of maximal medical therapy. In his cohort, 13/127 (10.2%) patients presented with new onset DM, where one patient had bilateral disease. The mean age was 35.9 years (range: 20-51 years) and the mean duration from diagnosis of COVID-19 to the diagnosis of mucormycosis was 14.2 days. While 7/13 (53.8%) of the patients received systemic corticosteroids during the course of their treatment for COVID-19, six patients received no steroids or immunomodulators. The mean follow-up period was 9.2 weeks (range: 3-18 weeks) following discharge. Life salvage was possible in 100% of the cases. While overall globe salvage was possible in 42.8% (6/14 eyes), the globe could be preserved in 4/5 patients who received retrobulbar amphotericin-B injections.

CONCLUSIONS

Those involved in the care of COVID-19 patients should be aware about the possibility of recent-onset DM, even in patients without a history of corticosteroid therapy. Rarely, recent-onset DM following COVID-19 may present as rhino-orbital mucormycosis, which requires aggressive surgical and medical intervention.

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.