Necrotizing Mucormycosis of Wounds Following Combat Injuries, Natural Disasters, Burns, and Other Trauma

Complement Component C5a and Fungal Pathogen Induce Diverse Responses through Crosstalk between Transient Receptor Potential Channel (TRPs) Subtypes in Human Conjunctival Epithelial Cells

The conjunctiva has immune-responsive properties to protect the eye from infections. Its innate immune system reacts against external pathogens, such as fungi. The complement factor C5a is an important contributor to the initial immune response. It is known that activation of transient-receptor-potential-vanilloid 1 (TRPV1) and TRP-melastatin 8 (TRPM8) channels is involved in different immune reactions and inflammation in the human body. The aim of this study was to determine if C5a and mucor racemosus e voluminae cellulae (MR) modulate Ca2+-signaling through changes in TRPs activity in human conjunctival epithelial cells (HCjECs). Furthermore, crosstalk was examined between C5a and MR in mediating calcium regulation. Intracellular Ca2+-concentration ([Ca2+]i) was measured by fluorescence calcium imaging, and whole-cell currents were recorded using the planar-patch-clamp technique. MR was used as a purified extract. Application of C5a (0.05-50 ng/mL) increased both [Ca2+]i and whole-cell currents, which were suppressed by either the TRPV1-blocker AMG 9810 or the TRPM8-blocker AMTB (both 20 µM). The N-terminal peptide C5L2p (20-50 ng/mL) blocked rises in [Ca2+]i induced by C5a. Moreover, the MR-induced rise in Ca2+-influx was suppressed by AMG 9810 and AMTB, as well as 0.05 ng/mL C5a. In conclusion, crosstalk between C5a and MR controls human conjunctival cell function through modulating interactions between TRPV1 and TRPM8 channel activity.

Invasive fungal infections in wars, following explosives and natural disasters: A narrative review

Infections are well-known complications in patients following traumatic injuries, frequently leading to high morbidity and mortality. In particular, trauma occurring in disaster settings, both natural and man-made, such as armed conflicts and explosives detonation, results in challenging medical conditions that impede the best management practices. The incidence of invasive fungal infections (IFI) is increasing in trauma patients who lack the typical risk factors like an immune compromised state or others. This narrative review will focus on IFI as a direct complication after natural disasters, wars, and man-made mass destruction with a summary of the available evidence about the epidemiology, clinical manifestations, risk factors, microbiology, and proper management. In this setting, the clinical manifestations of IFI may include skin and soft tissue infections, osteomyelitis, visceral infections, and pneumonia. IFI should be considered in the war inflicted patients who are exposed to unsterile environments or have wounds contaminated with soil and decaying organic matter.

Multiple roles for hypoxia inducible factor 1-alpha in airway epithelial cells during mucormycosis

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

Meeting the Therapeutic Challenges of Emergent and Rare Invasive Fungal Diseases Through Novel Clinical Trial Designs

Treatments for emerging and rare invasive fungal diseases (IFDs) represent a critical unmet medical need. For IFDs that occur less frequently than invasive aspergillosis, such as mucormycosis, hyalohyphomycosis, and phaeohyphomycosis, randomized controlled clinical trials are impractical and unlikely to meet urgent public health needs. Understanding regulatory approaches for approval of drugs for rare cancers and rare metabolic diseases could help meet the challenges of studying drugs for rare IFDs. A single-arm, controlled clinical trial with a high-quality external control(s), with confirmatory evidence from nonclinical studies, including pharmacokinetic/pharmacodynamic data in predictive animal models of the disease may support findings of effectiveness of new drugs and biologics. Control populations may include historical controls from published literature, patient registries, and/or contemporaneous external control groups. Continuous engagement among clinicians, industrial sponsors, and regulatory agencies to develop consensus on trial design and innovative development pathways for emergent and rare invasive fungal diseases is important.

A Seminested PCR Method for the Diagnosis of Invasive Fungal Infections in Combat Injured

Background

Among combat injured, invasive fungal infections (IFIs) result in significant morbidity. Cultures and histopathology are the primary diagnostic methods for IFIs, but they have limitations. We previously evaluated a panfungal polymerase chain reaction assay, which was 83% sensitive and 99% specific for angioinvasive IFIs. Here, we evaluated 3 less resource-intensive seminested assays targeting clinically relevant fungi in the order Mucorales and genera Aspergillus and Fusarium.

Methods

Formalin-fixed paraffin-embedded tissue specimens from a multicenter trauma IFI cohort (2009-2014) were used. Cases were US military personnel injured in Afghanistan with histopathologic IFI evidence. Controls were patients with similar injury patterns and no laboratory IFI evidence (negative culture and histopathology). Seminested assays specific to Mucorales (V4/V5 regions of 18S rDNA), Aspergillus (mitochondrial tRNA), and Fusarium (internal transcribed spacer [ITS]/28A regions of DNA) were compared with a panfungal assay amplifying the internal transcribed spacer 2 region of rDNA and to histopathology.

Results

Specimens from 92 injury sites (62 subjects) were compared with control specimens from 117 injuries (101 subjects). We observed substantial agreement between the seminested and panfungal assays overall, especially for the order Mucorales. Moderate agreement was observed at the genus level for Aspergillus and Fusarium. When compared with histopathology, sensitivity and specificity of seminested assays were 67.4% and 96.6%, respectively (sensitivity increased to 91.7% when restricted to sites with angioinvasion).

Conclusions

Prior studies of seminested molecular diagnostics have focused on culture-negative samples from immunocompromised patients. Our findings underscore the utility of the seminested approach in diagnosing soft-tissue IFIs using formalin-fixed paraffin-embedded tissue samples, especially with angioinvasion.

The Impact of Dimitrios P. Kontoyiannis on Mucormycosis Research

Dimitrios P [...].

Development of a Combat-Relevant Murine Model of Wound Mucormycosis: A Platform for the Pre-Clinical Investigation of Novel Therapeutics for Wound-Invasive Fungal Diseases

Wound-invasive fungal diseases (WIFDs), especially mucormycosis, have emerged as life-threatening infections during recent military combat operations. Many combat-relevant fungal pathogens are refractory to current antifungal therapy. Therefore, animal models of WIFDs are urgently needed to investigate new therapeutic solutions. Our study establishes combat-relevant murine models of wound mucormycosis using Rhizopus arrhizus and Lichtheimia corymbifera, two Mucorales species that cause wound mucormycosis worldwide. These models recapitulate the characteristics of combat-related wounds from explosions, including blast overpressure exposure, full-thickness skin injury, fascial damage, and muscle crush. The independent inoculation of both pathogens caused sustained infections and enlarged wounds. Histopathological analysis confirmed the presence of necrosis and fungal hyphae in the wound bed and adjacent muscle tissue. Semi-quantification of fungal burden by colony-forming units corroborated the infection. Treatment with liposomal amphotericin B, 30 mg/kg, effectively controlled R. arrhizus growth and significantly reduced residual fungal burden in infected wounds (p < 0.001). This study establishes the first combat-relevant murine model of wound mucormycosis, paving the way for developing and evaluating novel antifungal therapies against combat-associated WIFDs.

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.

PCR diagnostic platforms for non-Aspergillus mold infections: ready for routine implementation in the clinic?

INTRODUCTION

While Aspergillus spp. remain the predominant cause of invasive mold infections, non-Aspergillus molds, such as the Mucorales or Fusarium spp., account for an increasing proportion of cases. The diagnosis of non-Aspergillus invasive mold infections (NAIMI) is challenging because of the low sensitivity and delay of conventional microbiological tests. Therefore, there is a particular interest to develop molecular tools for their early detection in blood or other clinical samples.

AREAS COVERED

This extensive review of the literature discusses the performance of Mucorales-specific PCR and other genus-specific or broad-range fungal PCR that can be used for the diagnosis of NAIMI in diverse clinical samples, with a focus on novel technologies.

EXPERT OPINION

PCR currently represents the most promising approach, combining good sensitivity/specificity and ability to detect NAIMI in clinical samples before diagnosis by conventional cultures and histopathology. Several PCR assays have been designed for the detection of Mucorales in particular, but also Fusarium spp. or Scedosporium/Lomentospora spp. Some commercial Mucorales PCRs are now available. While efforts are still needed for standardized protocols and the development of more rapid and simpler techniques, PCR is on the way to becoming an essential test for the early diagnosis of mucormycosis and possibly other NAIMIs.

Molecular mechanisms that govern infection and antifungal resistance in Mucorales

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

The potential for rapid antigen testing for mucormycosis in the context of COVID-19

INTRODUCTION

Mucormycosis is a highly aggressive angio-invasive disease of humans caused by Mucorales fungi. Prior to the COVID-19 pandemic, mucormycosis was a rare mycosis typically seen in immunocompromised patients with hematological malignancies or in transplant recipients. During the second wave of the pandemic, there was a dramatic increase in the disease, especially in India where a unique set of circumstances led to large numbers of life-threatening and disfiguring rhino-orbital-cerebral mucormycosis (ROCM) infections.

AREAS COVERED

The review examines mucormycosis as a super-infection of COVID-19 patients, and the risk factors for COVID-19-associated mucormycosis (CAM) that drove the ROCM epidemic in India. The limitations of current diagnostic procedures are identified, and the measures needed to improve the speed and accuracy of detection discussed.

EXPERT OPINION

Despite increased awareness, global healthcare systems remain unprepared for further outbreaks of ROCM. Current diagnosis of the disease is slow and inaccurate, negatively impacting on patient survival. This is most evident in low- to middle-income countries which lack suitably equipped diagnostic facilities for rapid identification of the infecting pathogens. Rapid antigen testing using point-of-care lateral-flow assays could potentially have aided in the quick and accurate diagnosis of the disease, allowing earlier intervention with surgery and Mucorales-active antifungal drugs.

A 17-year-old student with ankle sprain to leg amputation

Cutaneous mucormycosis with ischemic complications is a life-threatening condition with high mortality rates, particularly in immunocompromised individuals. The incidence of mucormycosis has increased during the COVID-19 pandemic due to reduced immunity. We present the case of a 17-year-old high school student who experienced a sprained left lower extremity, followed by worsening pain and swelling due to the topical application of unknown local herbs. Eighteen days after the injury, she was admitted to our department in a comatose state with left lower limb ischemia. The patient had a history of uncontrolled diabetes mellitus and displayed a necrotic lesion on her left ankle, suggestive of invasive infectious fungi disease. Diagnostic procedures, including tissue staining and molecular analysis, identified Rhizopus oryzae as the causative organism. Administering amphotericin B yielded marked improvement, but the patient necessitated a mid-thigh amputation to curtail the infection's advance, culminating in her successful discharge post-treatment.

Cutaneous mucormycosis in the immunocompromised host: An important cause of persistent post traumatic skin lesions

We describe a case of a 31-year-old man with a history of ocular non-Hodgkin's lymphoma who presented with a large 12-cm non-resolving traumatic skin lesion on his back. Biopsy showed fungal elements, and on fungal culture, Rhizopus arrhizus (formerly R. oryzae) was isolated. Cutaneous mucormycosis is an important diagnostic consideration for a non-resolving skin lesion in an immunocompromised host. Early tissue sampling is key, and diagnostic certainty is particularly important because first line therapy, liposomal amphotericin B, has significant systemic toxicities, notable renal toxicity, and is therefore challenging to continue empirically. Surgical debridement is an integral part of therapy, highlighting the need for early multidisciplinary care in patients with cutaneous mucormycosis.

Mucormycosis: update on clinical presentation, diagnosis, and treatment

PURPOSE OF REVIEW

Mucormycosis (MCR) is a common opportunistic mold infection, and Mucorales were recently designated by WHO as priority pathogens. The interest in this infection has risen significantly since the major outbreak of MCR in the context of the COVID-19 pandemic, particularly in India. Herein, we summarize recently (last 24 months) published information regarding clinical aspects of MCR.

RECENT FINDINGS

The disease remains protean in its clinical presentation, difficult to diagnose, and challenging to treat. In 2021, cases of COVID-19-associated mucormycosis (CAM) exploded in India during COVID-19 and manifested primarily as sino-orbital or sino-cerebral disease. Its classic risk factors included the triad of COVID-19, uncontrolled diabetes mellitus and use of corticosteroids. Despite difficulties in the timely diagnosis of MCR, significant progress has been made with the use of molecular techniques in blood to assist with earlier diagnosis, which can facilitate earlier appropriate therapy and improve outcomes. In addition, advances have been made in the use of imaging to stage the disease, determining what types of multimodal therapy are required depending on staging, and tissue-based identification of Mucorales.

SUMMARY

Although the outlook for MCR has improved, effective new antifungals, risk stratification, and the optimal multimodality approaches remain an unmet need.

Mucorales-disseminated infection in burn wound

A previously fit and well man in his 50s was rescued from a burning apartment with Glasgow Coma Scale 3 and admitted to the burn intensive care unit with 18% mixed dermal and full thickness burns and inhalation injury. He received standardised acute burn treatment according to the Emergency Management of Severe Burn guidelines and was found to have acute kidney injury requiring dialysis and cerebral watershed infarcts. The burns were deep especially on the left leg that was deemed unsalvageable and on day 8, he underwent a mid-femoral amputation.A wound swab on day 8 grew mould and with progression of skin necrosis, Mucorales infection was clinically suspected. Microbiological assessment of the swab confirmed Mucorales infection-an invasive fungus with the ability to invade blood vessels leading to vessel thrombosis and tissue necrosis and associated with high mortality. Recommended radical debridement with free cutaneous margins was not possible due to the widespread disease, and the patient was treated conservatively with antifungal therapy and survived.

Hyphae of Rhizopus arrhizus and Lichtheimia corymbifera Are More Virulent and Resistant to Antifungal Agents Than Sporangiospores In Vitro and in Galleria mellonella

Mucorales species cause debilitating, life-threatening sinopulmonary diseases in immunocompromised patients and penetrating wounds in trauma victims. Common antifungal agents against mucormycosis have significant toxicity and are often ineffective. To evaluate treatments against mucormycosis, sporangiospores are typically used for in vitro assays and in pre-clinical animal models of pulmonary infections. However, in clinical cases of wound mucormycosis caused by traumatic inoculation, hyphal elements found in soil are likely the form of the inoculated organism. In this study, Galleria mellonella larvae were infected with either sporangiospores or hyphae of Rhizopus arrhizus and Lichtheimia corymbifera. Hyphal infections resulted in greater and more rapid larval lethality than sporangiospores, with an approximate 10-16-fold decrease in LD50 of hyphae for R. arrhizus (p = 0.03) and L. corymbifera (p = 0.001). Liposomal amphotericin B, 10 mg/kg, was ineffective against hyphal infection, while the same dosage was effective against infections produced by sporangiospores. Furthermore, in vitro, antifungal susceptibility studies show that minimum inhibitory concentrations of several antifungal agents against hyphae were higher when compared to those of sporangiospores. These findings support using hyphal elements of Mucorales species for virulence testing and antifungal drug screening in vitro and in G. mellonella for studies of wound mucormycosis.

Mucormycosis: A 14-Year Retrospective Study from a Tertiary Care Center in Lebanon

Mucormycosis (MCM) is a serious invasive fungal disease (IFD) that is associated with high mortality, particularly in immunocompromised patients. A global surge in MCM cases was reported with the COVID-19 pandemic. We analyzed all recorded cases of MCM at the American University of Beirut Medical Center (AUBMC), a tertiary care center in Lebanon, over 14 years. We aimed to identify the incidence, seasonal variation, clinical characteristics of the patients, and predictors of mortality. We conducted a retrospective chart review between 1 January 2008 and 1 January 2023. All patients with proven or probable MCM were included in the study. Proven or probable MCM was defined by positive histopathology and/or positive cultures. A total of 43 patients were identified as having MCM. Their median age was 53 years, and the majority were males (58.1%). Most of the cases were diagnosed in the autumn season. In total, 67.4% of the patients had hematological malignancies (HMs), and 34.9% had uncontrolled diabetes mellitus (DM). The most common site of involvement was rhino-orbital-cerebral MCM (ROCM) (74%). The annual cases of MCM per 100,000 patient days increased markedly during the years of the COVID-19 pandemic (from 0 to 4.4 cases/100,000 patient days to 7.5 cases/100,000 during 2020 and 2021). Liposomal amphotericin (Ampho) B was used as a first-line agent in most of the patients (86%). The median duration of total in-hospital antifungal therapy was 21 days and 51.2% of the patients received step-down therapy with azoles. Surgical debridement and isolated ROCM were significantly associated with survival (p-value: 0.02 and <0.001, respectively). All-cause mortality was 46.7%, with chronic renal disease being significantly associated with mortality (p-value < 0.05). The incidence of MCM has been increasing at our institution, particularly since the COVID-19 pandemic. Early diagnosis, treatment, and surgical debridement improve patient outcomes and overall survival.

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.

Parietal composition of Lichtheimia corymbifera: Differences between spore and germ tube stages and host-pathogen interactions

The molecular composition and structural organization of the cell wall of filamentous fungi underlie the ability of the host to identify them as pathogens. Although the organization of the fungal cell wall, composed of 90% polysaccharides, is similar from one fungus to another, small variations condition their ability to trigger pattern recognition receptors. Because the incidence of mucormycosis, an emerging life-threatening infection caused by the species of the order Mucorales is increasing worldwide, the precise composition of the cell wall of two strains of Lichtheimia corymbifera was investigated in the early growth stages of germination (spores and germ-tubes) using trimethylsilylation and confocal microscopy. This study also characterizes the response of THP-1 cells to Mucorales. The study identified the presence of uncommon monosaccharides (fucose, galactose, and glucuronic acid) whose respective proportions vary according to the germination stage, revealing early parietal reorganization. Immunofluorescence studies confirmed the exposure of β-glucan on the surface of swollen spores and germ-tubes. Both spores and germ-tubes of L. corymbifera promoted an early and strong pro-inflammatory response, through TLR-2. Our results show the singularity of the cell wall of the order Mucorales, opening perspectives for the development of specific diagnostic biomarkers.

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.

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.

Cutaneous Mucormycosis in an Immunocompetent Child following a Minor Skin Trauma

Cutaneous mucormycosis is a rare infection by the Zygomycetes class of fungi, which carries significant morbidity and mortality. While typically associated in patients with underlying immunocompromise (especially in the current era of COVID-19), it may also be seen in immunocompetent patients. We report a case of a healthy 4-year-old girl with acute right leg cellulitis and abscess formation, who required surgical debridement following poor response to antibiotic therapy and initial incision and drainage. Tissue histopathology returned cutaneous zygomycosis despite negative tissue cultures. At four-week follow-up, her wound was healed well. Clinicians should maintain a high degree of clinical suspicion for cutaneous mucormycosis given its potential for rapidly progressive and disseminated disease. Currently, the mainstay of diagnostic investigations is tissue histopathology, with a growing role for tissue fungal PCR. Treatment involves multidisciplinary management between surgeons and Infectious Diseases team to guide the role for surgical debridement and antifungal therapy.

Cutaneous Invasive Fungal Infections with Saksenaea Species in Immunocompetent Patients in Europe: A Systematic Review and Case Report

Invasive fungal infections from Saksenaea, a fungus belonging to the Mucorales, have been rarely reported in central European climate zones. This study aims to raise awareness of invasive cutaneous infections with Saksenaea species. The first case of a cutaneous infection was diagnosed in Switzerland in an immunocompetent 79-year-old patient. A minor skin trauma of her left lower leg led to a fulminant infection causing necrosis and extensive loss of tissue. The combination of surgical debridement and administration of antifungal agents averted a prolonged course with a possible worse outcome. A pedicled hemisoleus muscle flap was used to reconstruct the defect and treatment was continued for 63 days.

Methods

A systematic review in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis guidelines was conducted to identify all European cases of infection with Saksenaea species in immunocompetent hosts. The epidemiology, clinical presentation, microbiological diagnosis, and management of cases reported in Europe were summarized and analyzed.

Conclusions

The prognosis of soft tissue infections with Saksenaea species. depends on early diagnosis and appropriate antifungal and surgical treatment. Reconstruction can be successful under ongoing antifungal treatment.

Global Cutaneous Mucormycosis: A Systematic Review

Cutaneous mucormycosis is the third most common clinical type of mucormycosis. The signs and symptoms vary widely, and it is important to make the diagnosis as early as possible in order to achieve a better outcome. We present a systematic review of its epidemiology, clinical presentation, diagnosis, and treatment, analyzing cases published from 1958 until 2021. The review was conducted according to the PRISMA guidelines and included 693 cases from 485 articles from 46 countries. Most publications were from North America (256 cases, 36.9%) and Asia (216 cases, 31.2%). The most common risk factors were diabetes mellitus (20%) and hematological malignancies (15.7%). However, a large proportion of published cases (275, 39.6%) had no identified underlying disease. The most common mode of transmission was trauma (54%), and 108 (15.6%) cases were healthcare-associated. In this review, 291 (42.5%) patients had localized infection, and 90 (13%) had disseminated mucormycosis. In Europe, N. America and S. America, the most common genus was Rhizopus spp., while in Asia it was Apophysomyces spp. (34.7%). Treatment was performed with antifungals, mainly amphotericin B, and/or surgery. Mortality was significantly lower when both antifungals and surgery were applied (29.6%).

The Indigenous Volatile Inhibitor 2-Methyl-2-butene Impacts Biofilm Formation and Interspecies Interaction of the Pathogenic Mucorale Rhizopus arrhizus

2-Methyl-2-butene has recently been reported to be a quorum-based volatile self-inhibitor of spore germination and growth in pathogenic Mucorale Rhizopus arrhizus. The present study aimed to elucidate if this compound can influence R. arrhizus biofilm formation and interspecies interaction. The compound was found to significantly decrease R. arrhizus biofilm formation (p < 0.001), with nearly 25% and 50% lesser biomass in the biofilms cultured with exposure to 4 and 32 µg/ml of 2-methyl-2-butene, respectively. The growth of pre-formed biofilms was also impacted, albeit to a lesser extent. Additionally, 2-methyl-2-butene was found to self-limit R. arrhizus growth during interspecies interaction with Staphylococcus aureus and was detected at a substantially greater concentration in the headspace of co-cultures (2338.75 µg/ml) compared with monocultures (69.52 µg/ml). Some of the C5 derivatives of this compound (3-methyl-1-butanol, 2-methyl-2-butanol, and 3-methyl-1-butyne) were also observed to partially mimic its action, such as inhibition of spore germination, but did not impact R. arrhizus biofilm formation. Finally, the treated R. arrhizus displayed changes in fungal morphology suggestive of cytoskeletal alterations, such as filopodia formation, blebs, increased longitudinal folds and/or corrugations, and finger-like and sheet-like surface protrusions, depending upon the concentration of the compound(s) and the planktonic or biofilm growth mode.

The importance of mucormycosis infections on example of Rhino Orbital Cerebral Mucormycosis

Mucormycosis is an angioinvasive fungal infection, characterized by high morbidity and mortality and is strongly dependent on the patient’s general health condition, initial site of infection, and the time from diagnosis to treatment commencement. It has been reported that the occurrence of mucormycosis has increased rapidly, also among immunocompetent patients. Moreover, the rise in number is expected to continue. Among all clinical manifestations of mucormycosis, the rhino-orbital-cerebral type (ROCM) is the most common. The aim of this article is to increase the awareness of mucoral infections, especially ROCM, and to describe its first symptoms, as proper treatment requires immediate surgical and medical intervention.

Mucormycosis at a tertiary-care center in Mexico. A 35-year retrospective study of 214 cases

BACKGROUND

Mucormycosis is a rare, invasive disease associated with high mortality rates, produced by opportunistic pathogens related to the Mucorales order and characterised by a diverse range of clinical forms; acute rhino-orbital-cerebral and pulmonary symptoms are the most reported ones.

OBJECTIVES

To report the experience of mucormycosis observed in a tertiary-care hospital in Mexico for 35 years.

METHODS

This was a retrospective, descriptive and observational study on mucormycosis at a tertiary-care hospital in Mexico from January 1985 to December 2019. Demographic and clinical data and mycological and histopathological records were selected.

RESULTS

Two hundred fourteen proven cases of mucormycosis for 35 years at a tertiary-care hospital in Mexico were included. Most of the cases were male patients with a median age of 45 years. The two most associated underlying diseases were diabetes mellitus (76.6%) and haematologic malignancy (15.4%). The three primary clinical forms were as follows: rhino-orbito-cerebral (75.9%), cutaneous (8.41%) and pulmonary (7.47%) mucormycosis. The most isolated agents were Rhizopus arrhizus (58.4%) and Lichtheimia corymbifera (12.3%). The overall therapeutic response was 58.5%, and the best response was observed with amphotericin B deoxycholate and surgical debridement.

CONCLUSION

Mucormycosis is an emerging disease, and its incidence has increased at our hospital over the years. In this study, the rhino-cerebral clinical type was the most frequent in patients with uncontrolled diabetes; the main aetiological agent was R. arrhizus. Early diagnosis, control of the underlying disease and prompt management may increase the survival rate.

Mucormycosis with cutaneous involvement. A retrospective study of 115 cases at a tertiary care hospital in Mexico

BACKGROUND/OBJECTIVES

Cutaneous mucormycosis is an emerging opportunistic mycosis caused by Mucorales. It can be divided into primary caused by trauma and secondary by extension of rhino-cerebral and disseminated cases. The objective is to present a retrospective study of cases of mucormycosis with cutaneous involvement.

METHODS

A retrospective and descriptive study was carried out. Mucormycosis patients were included and divided into two groups: a) Primary Cutaneous and b) Secondary Cutaneous. Mycological tests were performed; the agents were identified by morphology and molecular studies (PCR and sequencing); some cases underwent histopathology. Clinical data and response to treatment were collected.

RESULTS

115 cases were included, 18 of primary, and 97 of secondary cutaneous mucormycosis. Primary cutaneous mucormycosis was most associated with adhesive bands (44.4%) and trauma from traffic accidents (33.3%). The principal clinical form was extensive and deep necrotic ulcers. Secondary cutaneous mucormycosis cases were rhino-cerebral with uncontrolled diabetes (81.4%) The most frequent clinical presentation was necrosis of the eyelid and the nose (65.9%). In both groups, the principal agent was Rhizopus arrhizus, 38.8% and 74.2% respectively. The most effective treatment was the combination of amphotericin B with surgical debridement. The clinical and mycological cure was achieved in 31.0% of primary cases, and 44.4% for secondary cases.

CONCLUSION

Primary cutaneous mucormycosis is caused by implantation of the Mucorales due to trauma or rupture of the cutaneous barrier-breach, and secondary cutaneous mucormycosis develops as part of the rhino-cerebral process. The response to treatment depends on the extension and depth, as well as the predisposing factors.

Epidemiology and Diagnosis of Mucormycosis: An Update

Mucormycosis is an angioinvasive fungal infection, due to fungi of the order Mucorales. Its incidence cannot be measured exactly, since there are few population-based studies, but multiple studies have shown that it is increasing. The prevalence of mucormycosis in India is about 80 times the prevalence in developed countries, being approximately 0.14 cases per 1000 population. Diabetes mellitus is the main underlying disease globally, especially in low and middle-income countries. In developed countries the most common underlying diseases are hematological malignancies and transplantation. Τhe epidemiology of mucormycosis is evolving as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and as the modern diagnostic tools lead to the identification of previously uncommon genera/species such as Apophysomyces or Saksenaea complex. In addition, new risk factors are reported from Asia, including post-pulmonary tuberculosis and chronic kidney disease. New emerging species include Rhizopus homothallicus, Thamnostylum lucknowense, Mucor irregularis and Saksenaea erythrospora. Diagnosis of mucormycosis remains challenging. Clinical approach to diagnosis has a low sensitivity and specificity, it helps however in raising suspicion and prompting the initiation of laboratory testing. Histopathology, direct examination and culture remain essential tools, although the molecular methods are improving. The internal transcribed spacer (ITS) region is the most widely sequenced DNA region for fungi and it is recommended as a first-line method for species identification of Mucorales. New molecular platforms are being investigated and new fungal genetic targets are being explored. Molecular-based methods have gained acceptance for confirmation of the infection when applied on tissues. Methods on the detection of Mucorales DNA in blood have shown promising results for earlier and rapid diagnosis and could be used as screening tests in high-risk patients, but have to be validated in clinical studies. More, much needed, rapid methods that do not require invasive procedures, such as serology-based point-of-care, or metabolomics-based breath tests, are being developed and hopefully will be evaluated in the near future.

Combat trauma-related invasive fungal wound infections

Purpose of review

This review highlights research from the past five years on combat trauma-related invasive fungal wound infections (IFIs) with a focus on risk stratification to aid patient management, microbiology, and diagnostics.

Recent Findings

A revised classification scheme stratifies wounds into three risk groups: IFI, High Suspicion of IFI, and Low Suspicion of IFI. This stratification is based on persistence of wound necrosis and laboratory fungal evidence, presence of signs/symptoms of deep soft-tissue infections, and the need for antifungals. Use of this classification could allow for prioritization of antifungal therapy. Further, IFIs delay wound healing, particularly when caused by fungi of the order Mucorales. Lastly, molecular sequencing offers promising and complimentary results to the gold standard histopathology.

Summary

Optimal management of combat-related IFIs depends on early tissue-based diagnosis with aggressive surgical debridement and concomitant dual antifungal therapy. Further research on clinical decision support tools and rapid diagnostics are needed.

Tornadic Shear Stress Induces a Transient, Calcineurin-Dependent Hypervirulent Phenotype in Mucorales Molds

Trauma-related necrotizing myocutaneous mucormycosis (NMM) has a high morbidity and mortality in victims of combat-related injuries, geometeorological disasters, and severe burns. Inspired by the observation that several recent clusters of NMM have been associated with extreme mechanical forces (e.g., during tornados), we studied the impact of mechanical stress on Mucoralean biology and virulence in a Drosophila melanogaster infection model. In contrast to other experimental procedures to exert mechanical stress, tornadic shear challenge (TSC) by magnetic stirring induced a hypervirulent phenotype in several clinically relevant Mucorales species but not in Aspergillus or Fusarium Whereas fungal growth rates, morphogenesis, and susceptibility to noxious environments or phagocytes were not altered by TSC, soluble factors released in the supernatant of shear-challenged R. arrhizus spores rendered static spores hypervirulent. Consistent with a rapid decay of TSC-induced hypervirulence, minimal transcriptional changes were revealed by comparative RNA sequencing analysis of static and shear-challenged Rhizopus arrhizus However, inhibition of the calcineurin/heat shock protein 90 (hsp90) stress response circuitry by cyclosporine and tanespimycin abrogated the increased pathogenicity of R. arrhizus spores following TSC. Similarly, calcineurin loss-of-function mutants of Mucor circinelloides displayed no increased virulence capacity in flies after undergoing TSC. Collectively, these results establish that TSC induces hypervirulence specifically in Mucorales and point out the calcineurin/hsp90 pathway as a key orchestrator of this phenotype. Our findings invite future studies of topical calcineurin inhibitor treatment of wounds as an adjunct mitigation strategy for NMM following high-energy trauma.IMPORTANCE Given the limited efficacy of current medical treatments in trauma-related necrotizing mucormycosis, there is a dire need to better understand the Mucoralean pathophysiology in order to develop novel strategies to counteract fungal tissue invasion following severe trauma. Here, we describe that tornadic shear stress challenge transiently induces a hypervirulent phenotype in various pathogenic Mucorales species but not in other molds known to cause wound infections. Pharmacological and genetic inhibition of calcineurin signaling abrogated hypervirulence in shear stress-challenged Mucorales, encouraging further evaluation of (topical) calcineurin inhibitors to improve therapeutic outcomes of NMM after combat-related blast injuries or violent storms.

Traumatic Mucormycosis of Auricular Cartilage in an Iranian Diabetic Patient

Mucormycosis is an uncommon and acute fungal infection, with high morbidity and mortality. Traumatic mucormycosis mainly occurs in military conflicts, civilian trauma, and vehicle accidents. Hurricanes, tornadoes, floods, and tsunamis also play a major role in causing mucormycosis by inoculation. Herein, we presented a case of trauma-related mucormycosis in a 70-year-old diabetic male. He referred to a specialty clinic due to the auricular swelling after having fallen and having a major trauma in his ear. Pathologic examination of necrotic cartilage revealed broad ribbon like aseptate hyphae. Antifungal therapy with amphotericin B deoxycholate (1.5 mg/kg/day) was administered for 6 weeks as an initial therapy, and the patient was discharged with a regimen of posaconazole oral solution (400 mg PO bid with meals) for 8 weeks. He followed up for one year and there was no recurrence of the infection. In conclusion, traumatic mucormycosis is a rare but potentially life-threatening fungal infection. Early diagnosis and surgical excision are essential regarding the management of this critical condition. Knowing the underlying diseases is preferable to early diagnosis and timely initiation of antifungal therapy in order to improve survival rates.

Complication of massive trauma by fungal infection and bone tuberculosis

We report a middle aged man who was admitted with severe necrotising fasciitis following a motor vehicle accident (MVA). Histopathology of the excised tissue suggested mucormycosis while a bone tissue culture revealed fully sensitive Mycobacterium tuberculosis. He received intravenous liposomal amphotericin B combined with multiple surgical debridements and ended with right shoulder disarticulation. In addition he completed a nine months course of anti-tuberculosis treatment. He remained stable one year following his admission. We believe that trauma contributed to both conditions by direct inoculation of fungal spores and through immunological reactivation of old healed tuberculosis focus. This case highlights the importance of considering diagnosis of invasive fungal infections following MVA.

Mould Infections of Traumatic Wounds: A Brief Narrative Review

Mould infections may follow traumatic injuries, with direct fungal inoculum in the site of injury and subsequent angioinvasion, possibly resulting in tissue necrosis and systemic dissemination. The pathogenesis of mould infections following trauma injuries presents unique features compared with classical mould infections occurring in neutropenic or diabetic patients, because a large fraction of post-traumatic mould infections is observed in previously healthy individuals. Most of the published clinical experience and research on mould infections following traumatic injuries regards soldiers and infections after natural disasters. However, following trauma and soil contamination (e.g., agricultural or automotive injuries) other immunocompetent individuals may develop mould infections. In these cases, delays in correct diagnosis and treatment may occur if pertinent signs such as necrosis and absent or reduced response to antibacterial therapy are not promptly recognized. Awareness of mould infections in at-risk populations is needed to rapidly start adequate laboratory workflow and early antifungal therapy in rapidly evolving cases to improve treatment success and reduce mortality.

Outbreaks of Mucorales and the Species Involved

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

Insect Bite-Associated Invasive Fungal Infections

Insect bites are rarely reported to result in myocutaneous mycoses. We reviewed the literature and report 22 cases. Molds were the most common pathogens (15), especially Mucorales (9). Infections were typically misdiagnosed, and 68% had necrotizing features, often requiring amputation or extensive surgery. Both immunocompetent and immunosuppressed patients were affected.