Recent Advances and Future Directions in the Understanding of Mucormycosis

Cutaneous mucormycosis with suspected dissemination in a patient with metastatic adrenocortical carcinoma

Mucormycosis is a frequently lethal fungal infection that most commonly affects patients with poorly controlled diabetes or other immunosuppressed states. We report the case of a suspected disseminated Rhizopus infection in a patient who was pursuing naturopathic treatment including mud baths for metastatic adrenocortical carcinoma. He was empirically treated with liposomal amphotericin B but opted to stop treatment following multiorgan failure. The patient passed away on the tenth day of his hospital admission.

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.

Comprehensive Review on the Virulence Factors and Therapeutic Strategies with the Aid of Artificial Intelligence against Mucormycosis

Mucormycosis, a rare but deadly fungal infection, was an epidemic during the COVID-19 pandemic. The rise in cases (COVID-19-associated mucormycosis, CAM) is attributed to excessive steroid and antibiotic use, poor hospital hygiene, and crowded settings. Major contributing factors include diabetes and weakened immune systems. The main manifesting forms of CAM─cutaneous, pulmonary, and the deadliest, rhinocerebral─and disseminated infections elevated mortality rates to 85%. Recent focus lies on small-molecule inhibitors due to their advantages over standard treatments like surgery and liposomal amphotericin B (which carry several long-term adverse effects), offering potential central nervous system penetration, diverse targets, and simpler dosing owing to their small size, rendering the ability to traverse the blood-brain barrier via passive diffusion facilitated by the phospholipid membrane. Adaptation and versatility in mucormycosis are facilitated by a multitude of virulence factors, enabling the pathogen to dynamically respond to various environmental stressors. A comprehensive understanding of these virulence mechanisms is imperative for devising effective therapeutic interventions against this highly opportunistic pathogen that thrives in immunocompromised individuals through its angio-invasive nature. Hence, this Review delineates the principal virulence factors of mucormycosis, the mechanisms it employs to persist in challenging host environments, and the current progress in developing small-molecule inhibitors against them.

"We've got to get out"-Strategies of human pathogenic fungi to escape from phagocytes

Human fungal pathogens are a deadly and underappreciated risk to global health that most severely affect immunocompromised individuals. A virulence attribute shared by some of the most clinically relevant fungal species is their ability to survive inside macrophages and escape from these immune cells. In this review, we discuss the mechanisms behind intracellular survival and elaborate how escape is mediated by lytic and non-lytic pathways as well as strategies to induce programmed host cell death. We also discuss persistence as an alternative to rapid host cell exit. In the end, we address the consequences of fungal escape for the host immune response and provide future perspectives for research and development of targeted therapies.

Rhino-Orbito-Cerebral Mucormycosis: A Challenging Case

Mucormycosis is a rare opportunistic fungal infection caused by Mucorales and associated with high mortality rates. Rhino-orbito-cerebral localization usually occurs in individuals with uncontrolled diabetes mellitus. We report the case of a 41-year-old male, with previously undiagnosed diabetes, who presented with unilateral facial extensive black eschar and signs of diabetic ketoacidosis. Cerebral magnetic resonance imaging showed left pansinusitis, left craniofacial edematous infiltrate, and left proptosis. A left internal temporal abscess was identified at an early pre-suppurative stage. Magnetic resonance angiography revealed total occlusion of the left intracranial internal carotid artery. A histopathological study of nasal mucosa biopsy suggested mucormycosis. According to the clinical presentation and the radiological and histopathological findings, rhino-orbito-cerebral mucormycosis was presumed. Culture of nasal, ocular, and skin lesion specimens grew Rhizomucor sp. and confirmed the diagnosis. The patient was treated with systemic liposomal amphotericin B. He died of multiple organ failure before surgical debridement was possible as he was in critical condition requiring stabilization before surgical treatment.

COVID-19 and Mucormycosis of Orofacial Region: A Scoping Review

During the second wave of coronavirus disease, or COVID-19, infection due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus in the year 2021 around the globe, there is a surge in the number of cases of mucormycosis or "Black Fungus" that is directly/indirectly associated with COVID-19. In this review article, mucormycosis of the orofacial region has gained importance from the maximum published literature (45 articles) from various databases like PubMed, Google Scholar, Scopus, Web of Science, and Embase. Rhino-orbital cerebral mucormycosis (ROCM) is a fatal condition associated with COVID-19 among categories of mucormycosis such as pulmonary, oral, gastrointestinal, cutaneous, and disseminated. ROCM targets the maxillary sinus, also involving teeth of the maxilla, orbits, and ethmoidal sinus. These are of particular interest to dentists and oral pathologists for proper diagnosis and identification. Co-morbid conditions, especially diabetes mellitus type II, have to be monitored carefully in COVID-19 patients as they have a higher risk of developing mucormycosis. In this review article, various presentations of COVID-19-linked mucormycosis are mentioned having particular emphasis on pathogenesis, signs and symptoms, clinical presentation, various diagnostic modalities including histopathology, radiology like CT and MRI, serology, tissue culture, various laboratory investigations, treatment protocols, management with prognosis, and so on. Any suspected case of mucormycosis needs quick detection and treatment since it progresses quickly due to the destructive course of infection. Long-term follow-up along with proper care is a must to detect any kind of recurrence.

Ibrexafungerp, a Novel Triterpenoid Antifungal in Development for the Treatment of Mold Infections

Molds are ubiquitous in the environment, and immunocompromised patients are at substantial risk of morbidity and mortality due to their underlying disease and the resistance of pathogenic molds to currently recommended antifungal therapies. This combination of weakened-host defense, with limited antifungal treatment options, and the opportunism of environmental molds renders patients at risk and especially vulnerable to invasive mold infections such as Aspergillus and members of the Order Mucorales. Currently, available antifungal drugs such as azoles and echinocandins, as well as combinations of the same, offer some degree of efficacy in the prevention and treatment of invasive mold infections, but their use is often limited by drug resistance mechanisms, toxicity, drug-drug interactions, and the relative paucity of oral treatment options. Clearly, there is a need for agents that are of a new class that provides adequate tissue penetration, can be administered orally, and have broad-spectrum efficacy against fungal infections, including those caused by invasive mold organisms. Ibrexafungerp, an orally bioavailable glucan synthase inhibitor, is the first in a new class of triterpenoid antifungals and shares a similar target to the well-established echinocandins. Ibrexafungerp has a very favorable pharmacokinetic profile for the treatment of fungal infections with excellent tissue penetration in organs targeted by molds, such as the lungs, liver, and skin. Ibrexafungerp has demonstrated in vitro activity against Aspergillus spp. as well as efficacy in animal models of invasive aspergillosis and mucormycosis. Furthermore, ibrexafungerp is approved for use in the USA for the treatment of women with vulvovaginal candidiasis. Ibrexafungerp is currently being evaluated in clinical trials as monotherapy or in combination with other antifungals for treating invasive fungal infections caused by yeasts and molds. Thus, ibrexafungerp offers promise as a new addition to the clinician's armamentarium against these difficult-to-treat infections.

Targeted Delivery of Antifungal Liposomes to Rhizopus delemar

Mucormycosis (a.k.a. zygomycosis) is an often-life-threatening disease caused by fungi from the ancient fungal division Mucoromycota. Globally, there are nearly a million people with the disease. Rhizopus spp., and R. delemar (R. oryzae, R. arrhizus) in particular, are responsible for most of the diagnosed cases. Pulmonary, rhino-orbito-cerebral, and invasive mucormycosis are most effectively treated with amphotericin B (AmB) and particularly with liposomal formulations (e.g., AmBisome^®). However, even after antifungal therapy, there is still a 50% mortality rate. Hence, there is a critical need to improve therapeutics for mucormycosis. Targeting AmB-loaded liposomes (AmB-LLs) with the pathogen receptor Dectin-1 (DEC1-AmB-LLs) to the beta-glucans expressed on the surface of Aspergillus fumigatus and Candida albicans lowers the effective dose required to kill cells relative to untargeted AmB-LLs. Because Dectin-1 is an immune receptor for R. delemar infections and may bind it directly, we explored the Dectin-1-mediated delivery of liposomal AmB to R. delemar. DEC1-AmB-LLs bound 100- to 1000-fold more efficiently to the exopolysaccharide matrix of R. delemar germlings and mature hyphae relative to AmB-LLs. DEC1-AmB-LLs delivering sub-micromolar concentrations of AmB were an order of magnitude more efficient at inhibiting and/or killing R. delemar than AmB-LLs. Targeted antifungal drug-loaded liposomes have the potential to improve the treatment of mucormycosis.