Lomentospora prolificans: An Emerging Opportunistic Fungal Pathogen

Intra-abdominal nocardiosis and scedosporiosis in a dog: case report and literature review

A 2-y-old, intact female, mixed-breed dog was presented to the veterinary hospital with abdominal distension, anemia, and lethargy following a chronic history of nonspecific gastrointestinal signs. CBC and serum biochemistry revealed moderate nonregenerative anemia with neutrophilia, hypoalbuminemia, hyperglobulinemia, hypoglycemia, decreased urea and creatinine, and hypercholesterolemia. Abdominal radiographs and ultrasound revealed a large heterogeneous mesenteric mass and ascites. Abdominocentesis confirmed septic peritonitis with filamentous bacteria. Fine-needle aspiration of the mass yielded pyogranulomatous inflammation and hyphae. An exploratory laparotomy revealed a large cranial abdominal mass with granulomas present throughout the abdominal cavity. Due to the poor prognosis and disseminated disease, the owner elected euthanasia. Postmortem and histologic examinations detected intralesional mycetomas and bacterial colonies within the mesenteric masses. 16S ribosomal RNA gene PCR and sequencing using formalin-fixed, paraffin-embedded sections identified Nocardia yamanashiensis, Nocardioides cavernae, and Nocardioides zeicaulis. Fungal culture, PCR, and sequencing confirmed Scedosporium apiospermum. Our report highlights the importance of molecular methods in conjunction with culture and histologic findings for diagnosing coinfections caused by infrequent etiologic agents. Additionally, we provide a comprehensive literature review of Scedosporium apiospermum infections in dogs.

Emerging Fungal Infections of the Central Nervous System in the Past Decade: A Literature Review

INTRODUCTION

Invasive fungal infections affecting the central nervous system (CNS) are a major health concern worldwide associated with high mortality rates. Their increased incidence is largely due to an increase in the vulnerable immunocompromised population, changing environmental factors, and development of more accurate diagnostic methods. The aim of this article is to identify fungal causes of CNS infections that are recently emerging or have the potential to become emerging pathogens in the near future, as well as their clinical characteristics, including: Candida auris, Trichosporon spp., Blastomyces spp., Sporothrix spp., Talaromyces marneffei, Lomentospora prolificans, and Scedosporium spp.

METHODS

A review of the literature in PubMed in the last ten years was conducted to identify central nervous system infections caused by each of these fungi.

RESULTS

The review identified 10 cases caused by C. auris, 5 cases by Trichosporon spp., 82 cases by Blastomyces spp., 36 cases by Sporothrix spp., 21 cases by T. marneffei, 22 cases by Lomentospora prolificans, and 42 cases by Scedosporium spp.

DISCUSSION

The exact burden of these diseases remains difficult to ascertain, but their apparent rise underscores the urgent need for improved diagnostic, treatment, and management strategies against CNS fungal pathogens to improve outcomes against these life-threatening infections.

Two cases of fungemia due to Lomentospora prolificans in haematological patients with different outcome

Lomentospora prolificans is an uncommon cause of invasive fungal disease, but it is associated with high mortality because it is difficult to treat. Most of severe cases are produced in immunossupressed patients, especially in those with neutropenia and/or hematological malignancies. Resistance to the majority of antifungal agents can be still observed. Here we report two cases of L. prolificans fungemia with different outcome, since in one of these patients treatment with one of the new antifungals could be applied. Both patients were treated with different antifungal drugs, but only the second one survived due to therapy with fosmanogepix®. The current treatment is still based on a combination of conventional antifungal drugs, although in much cases this strategy is not sufficient. The introduction of new promising antifungal agents such as fosmanogepix® and olorofim® may open new perspectives in the treatment of invasive infections caused by L. prolificans, as in our patient.

Disseminated Lomentospora prolificans infection that could have been predicted: A case report

Lomentospora prolificans is a rare, filamentous fungus, that causes a disseminated infection in immunocompromised individuals. Disseminated infections caused by the fungus are difficult to diagnose early. It is resistant to multiple antifungal agents and has a high mortality rate. We encountered a case in which the involvement of this fungus was indicated by a history of antifungal prophylaxis and an elevated serum 1,3-beta-D-glucan (BDG) level. A 76-year-old female with myelodysplastic syndrome that developed into overt leukemia was administered oral posaconazole as antifungal prophylaxis. She was admitted to the hospital to determine the cause of her fever, where no new abnormalities other than an elevated serum BDG level were observed. Unfortunately, the patient died due to acute respiratory failure on the same day of admission. The day after her death, L. prolificans was detected in a blood culture taken upon her admission. L. prolificans should be suspected based on the history of antifungal prophylaxis and an elevated serum BDG level, as these are risk factors for infection by this pathogen. Blood cultures are useful to provide a diagnosis. If treated early, before it is detected in culture, the mortality rate can be decreased.

The Impact of the Fungal Priority Pathogens List on Medical Mycology: A Northern European Perspective

Fungal diseases represent a considerable global health concern, affecting >1 billion people annually. In response to this growing challenge, the World Health Organization introduced the pivotal fungal priority pathogens list (FPPL) in late 2022. The FPPL highlights the challenges in estimating the global burden of fungal diseases and antifungal resistance (AFR), as well as limited surveillance capabilities and lack of routine AFR testing. Furthermore, training programs should incorporate sufficient information on fungal diseases, necessitating global advocacy to educate health care professionals and scientists. Established international guidelines and the FPPL are vital in strengthening local guidance on tackling fungal diseases. Future iterations of the FPPL have the potential to refine the list further, addressing its limitations and advancing our collective ability to combat fungal diseases effectively. Napp Pharmaceuticals Limited (Mundipharma UK) organized a workshop with key experts from Northern Europe to discuss the impact of the FPPL on regional clinical practice.

Scedosporiosis and lomentosporiosis: modern perspectives on these difficult-to-treat rare mold infections

SUMMARYAlthough Scedosporium species and Lomentospora prolificans are uncommon causes of invasive fungal diseases (IFDs), these infections are associated with high mortality and are costly to treat with a limited armamentarium of antifungal drugs. In light of recent advances, including in the area of new antifungals, the present review provides a timely and updated overview of these IFDs, with a focus on the taxonomy, clinical epidemiology, pathogenesis and host immune response, disease manifestations, diagnosis, antifungal susceptibility, and treatment. An expansion of hosts at risk for these difficult-to-treat infections has emerged over the last two decades given the increased use of, and broader population treated with, immunomodulatory and targeted molecular agents as well as wider adoption of antifungal prophylaxis. Clinical presentations differ not only between genera but also across the different Scedosporium species. L. prolificans is intrinsically resistant to most currently available antifungal agents, and the prognosis of immunocompromised patients with lomentosporiosis is poor. Development of, and improved access to, diagnostic modalities for early detection of these rare mold infections is paramount for timely targeted antifungal therapy and surgery if indicated. New antifungal agents (e.g., olorofim, fosmanogepix) with novel mechanisms of action and less cross-resistance to existing classes, availability of formulations for oral administration, and fewer drug-drug interactions are now in late-stage clinical trials, and soon, could extend options to treat scedosporiosis/lomentosporiosis. Much work remains to increase our understanding of these infections, especially in the pediatric setting. Knowledge gaps for future research are highlighted in the review.

A case of Scedosporium prolificans pulmonary infection in a patient with acute myeloid leukemia

An elderly woman with a history of myelodysplastic syndrome complicated by cavitary pneumonia treated with antibiotics and antifungal therapy was admitted with severe sepsis and pulmonary opacities on imaging. Pulmonary infection with Scedosporium prolificans, was diagnosed on bronchopulmonary lavage (BAL). This common environmental fungus is known to cause rare but severe infection in immunocompromised hosts. The patient was diagnosed with progression to acute myeloid leukemia during the hospitalization for which chemotherapy was initiated. Despite broadening antifungal therapy, the patient developed multi-organ system failure and died.

Antifungal pipeline: Is there light at the end of the tunnel?

The misuse and overuse of classic antifungals have accelerated the development of resistance mechanisms, diminishing the efficacy of established therapeutic pathways and necessitating a shift towards alternative targets. Despite this pressing need for new treatments, the antifungal drug pipeline has been largely stagnant for the past three decades, primarily due to the high risks and costs associated with antifungal drug development, compounded by uncertain market returns. Extensive research durations, special patient populations and rigorous regulatory demands pose significant barriers to bringing novel antifungal agents to market. In response, the "push-pull" incentive model has emerged as a vital strategy to invigorate the pipeline and encourage innovation. This editorial critically examines the current clinical landscape and spotlights emerging antifungal agents, such as Fosmanogepix, Ibrexafungerp, and Olorofim, while also unraveling the multifaceted challenges faced in new antifungal drug development. The generation of novel antifungals offers a beacon of hope in the battle against antimicrobial resistance, but it is premature to declare them as definitive solutions. Their future role hinges on thorough clinical validation, cost-effectiveness assessments, and continuous post-marketing surveillance. Only through strategic implementation and integration with market strategies we can transform the landscape of antifungal development, addressing both the resistance crisis and the treatment challenges.

A case of Lomentospora prolificans endophthalmitis treated with the novel antifungal agent Olorofim

PURPOSE

To report a case of endogenous Lomentospora prolificans endophthalmitis treated with the novel antifungal agent Olorofim.

CASE REPORT

A 57-year-old man developed disseminated Lomentospora prolificans with right endophthalmitis on the background of immunosuppression following lung transplantation for interstitial lung disease. He was treated with early vitrectomy, intravitreal voriconazole, and systemic Olorofim, voriconazole and terbinafine. His symptoms improved and remained stable in the right eye. Eight weeks later the patient represented with Lomentopora prolificans endophthalmitis in the left eye when systemic voriconazole and terbinafine treatment were withdrawn. Despite aggressive treatment he ultimately succumbed due to vascular complications of extensive disseminated disease.

CONCLUSION

We report a rare case of disseminated Lomentosporosis with panophthalmitis in an immunocompromised host with prolonged survival on systemic Olorofim, voriconazole and terbinafine in conjunction with pars plana vitrectomy and intravitreal voriconazole. Early suspicion of an opportunistic fungal infection is critical, as managing disseminated disease is often unsuccessful. Despite presumed inherent resistance, intravitreal and systemic voriconazole appeared to limit disease progression in the right eye. The potential synergistic effects of combined antifungal therapy with orotomides warrant further investigation.

Infection of a Nylon Foil Orbital Implant Due to Fusarium brachygibbosum and Lomentospora prolificans After Intranasal Methamphetamine Use

The authors describe a case of nylon foil implant infection caused by Fusarium brachygibbosum , and Lomentospora prolificans following medial orbital wall fracture repair in the setting of postoperative nasal methamphetamine use. A 61-year-old male presented with OS pain and swelling after a physical assault on his face. A CT of maxillofacial bones without contrast showed a moderately comminuted fracture of the medial wall of the left orbit with depression of fracture fragments into the left ethmoid air cells. Six days after repair of the medial wall fracture, the patient returned with a new onset headache, OS pain, and swelling to the left medial canthal area. He reported snorting methamphetamine approximately 48 hours before his current presentation. CT imaging showed fat stranding and soft tissue density in the extraconal space adjacent to the left medial rectus muscle and chronic fracture deformity of lamina papyracea with approximately 4 mm of medial displacement of the fracture fragments. The patient showed little clinical improvement after 48 hours of intravenous antibiotics, which led to the removal of the nylon foil implant by a left orbitotomy. Intraoperative tissue cultures grew coagulase-negative Staphylococcus , F. brachygibbosum , and Lomentospora (Scedosporium) prolificans . The patient was subsequently transitioned to oral clindamycin 600 mg three times daily and voriconazole 200 mg two times daily. To the authors' knowledge, this is the first case report to document an association between snorted methamphetamine and a fungal infection of an orbital implant.

The role of the host-microbiome and metabolomics in sarcoidosis

Sarcoidosis is a complex inflammatory fibrotic disease that affects multiple organ systems. It is characterized by the infiltration of lymphocytes and mononuclear phagocytes, which form non-caseating granulomas in affected organs. The lungs and intrathoracic lymph nodes are the most commonly affected organs. The underlying cause of sarcoidosis is unknown, but it is believed to occur in genetically predisposed individuals who are exposed to pathogenic organisms, environmental contaminants, or self and non-self-antigens. Recent research has suggested that the microbiome may play a role in the development of respiratory conditions, including sarcoidosis. Additionally, metabolomic studies have identified potential biomarkers for monitoring sarcoidosis progression. This review will focus on recent microbiome and metabolomic findings in sarcoidosis, with the goal of shedding light on the pathogenesis and possible diagnostic and therapeutic approaches.

Fatal panresistant Lomentospora prolificans fungemia in a patient with aplastic anemia: First report from Türkiye

Lomentospora prolificans is an opportunistic pathogen that can cause invasive lomentosporiosis in immunocompromised patients. Patients with hematological malignancies and those who have undergone stem cell or solid organ transplantations are in the highest risk group. In addition to the limitations and delays in diagnostic possibilities, L. prolificans has a high mortality due to its resistance to all available antifungal drugs. In a patient diagnosed with aplastic anemia, we described the first case of L. prolificans in Türkiye. L. prolificans was identified in the blood culture, and despite the initiation of antifungal treatments, the fungemia resulted in mortality on the 7th day of intensive care hospitalization. This case highlights the importance of early recognition and prompt initiation of appropriate antifungal therapy to improve the outcome of patients with rare mold infections.

How to use direct microscopy for diagnosing fungal infections

BACKGROUND

Invasive fungal infections are an important cause of morbidity and mortality in a broad range of patients. Adequate and early diagnosis is a challenge, and of importance for improved survival. New molecular-based diagnostic methods are trend-setting yet with the drawback that conventional tests receive less attention, in the lab as well as in the clinical setting.

OBJECTIVE

We aimed to provide a useful recommendation for direct microscopy for effectively managing numerous specimens related to fungal infections, mainly covering opportunistic pathogens.

SOURCES

A PubMed literature search covering fungal direct microscopy was performed with no restriction on publication date.

CONTENT

Best practice recommendations targeting the role of direct microscopy in diagnosing fungal infections are given. This review highlights when to perform direct microscopy, displays main fungal morphologies, discusses the pitfalls related to microscopy and recommends how to best report the results to the clinicians.

IMPLICATION

In many samples, the performance of direct microscopy provides an important diagnostic benefit that is greater than culture alone. Fluorescent dyes improve the sensitivity and allow a fast and rapid read. Reporting includes the presence or absence of yeast forms, septate or non-septate hyphae, pigmentation, cellular location or any other specific structures being present. Visualization of fungal elements from a sterile body site is the proof of an infection, independent of other test reports.

Microwave-Assisted Synthesis of Aminophosphonic Derivatives and Their Antifungal Evaluation against Lomentospora prolificans

Lomentospora prolificans is a pathogenic and multidrug-resistant fungus that can infect both immunocompetent and immunocompromised patients, with mortality rates up to 87%. The World Health Organization (WHO) included this fungal species in its first list of 19 priority fungal pathogens, which focused on fungal pathogens that can cause invasive acute and subacute systemic fungal infections. Therefore, there is a growing interest in finding new therapeutic alternatives. In this work, the synthesis of twelve α-aminophosphonates by the microwave-assisted Kabachnik-Fields reaction and twelve α-aminophosphonic acids by a monohydrolysis reaction is reported. All compounds were evaluated by the agar diffusion method as a preliminary screening in comparison with voriconazole, showing inhibition halos for compounds 7, 11, 13, 22 and 27. The five active compounds in the preliminary tests were evaluated against five strains of L. prolificans following protocol M38-A2 from CLSI. The results showed that these compounds exhibit antifungal activity in the concentration range of 900->900 μg/mL. Cytotoxicity against healthy COS-7 cells was also evaluated by the MTT assay, and it was shown that compound 22 was the least cytotoxic, with a viability of 67.91%, comparable to the viability exhibited by voriconazole (68.55%). Docking studies showed that the possible mechanism of action of the active compounds could be through the inhibition of the enzyme lanosterol-14-alpha-demethylase in an allosteric hydrophobic cavity.

Acrophialophora: A Comprehensive Review of Clinical Guidelines and Diagnosis

Acrophialophora is a saprotrophic genus of fungi found in both temperate and tropical regions. The genus is comprised of 16 species, with the subspecies A. fusispora and A. levis necessitating the most clinical concern. Acrophialophora is an opportunistic pathogen with a broad range of clinical manifestations; the fungus has been implicated in cases of fungal keratitis, lung infection, and brain abscess. Acrophialophora infection is particularly of concern for immunocompromised patients, who often present with a more severe disease course involving disseminated infection and may not exhibit typical symptoms. Early diagnosis and therapeutic intervention are critical to the successful clinical management of Acrophialophora infection. Guidelines for antifungal treatment have yet to be established, partially due to the lack of documented cases. Aggressive use of antifungal agents and long-term treatment is required, especially in immunocompromised patients and patients with systemic involvement, due to the potential for morbidity and mortality. In addition to outlining the rarity and epidemiology of the disease, this review provides an overview of the diagnosis and clinical management of Acrophialophora infection to facilitate an early diagnosis and appropriate interventions.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Pathogenic Drug Resistant Fungi: A Review of Mitigation Strategies

Fungal pathogens cause significant human morbidity and mortality globally, where there is a propensity to infect vulnerable people such as the immunocompromised ones. There is increasing evidence of resistance to antifungal drugs, which has significant implications for cutaneous, invasive and bloodstream infections. The World Health Organization (WHO) published a priority list of fungal pathogens in October 2022, thus, highlighting that a crisis point has been reached where there is a pressing need to address the solutions. This review provides a timely insight into the challenges and implications on the topic of antifungal drug resistance along with discussing the effectiveness of established disease mitigation modalities and approaches. There is also a need to elucidate the cellular and molecular mechanisms of fungal resistance to inform effective solutions. The established fungal decontamination approaches are effective for medical device processing and sterilization, but the presence of pathogenic fungi in recalcitrant biofilms can lead to challenges, particularly during cleaning. Future design ideas for implantable and reusable medical devices should consider antifungal materials and appropriates for disinfection, and where it is relevant, sterilization. Preventing the growth of mycotoxin-producing fungi on foods through the use of appropriate end-to-end processes is advisable, as mycotoxins are recalcitrant and challenging to eliminate once they have formed.

Lomentospora prolificans Disseminated Infections: A Systematic Review of Reported Cases

BACKGROUND

Lomentospora prolificans, a rare, highly virulent filamentous fungus with high rates of intrinsic resistance to antifungals, has been associated with different types of infections in immunocompromised as well as immunocompetent individuals.

OBJECTIVE

To systematically address all relevant evidence regarding L. prolificans disseminated infections in the literature.

METHODS

We searched Medline via PubMed and Scopus databases through July 2022. We performed a qualitative synthesis of published articles reporting disseminated infections from L. prolificans in humans.

RESULTS

A total of 87 studies describing 142 cases were included in our systematic review. The pathogen was most frequently reported in disseminated infections in Spain (n = 47), Australia (n = 33), the USA (n = 21), and Germany (n = 10). Among 142 reported cases, 48.5% were males. Underlying conditions identified for the majority of patients included malignancy (72.5%), hemopoietic stem cell transplantation (23.2%), solid organ transplantation (16%), and AIDS (2%). Lungs, central nervous system, skin, eyes, heart and bones/joints were the most commonly affected organs. Neutropenia was recorded in 52% of patients. The mortality rate was as high as 87.3%.

CONCLUSIONS

To the best of our knowledge, this is the first systematic review conducted on disseminated infections due to this rare microorganism. Physicians should be aware that L. prolificans can cause a diversity of infections with high mortality and primarily affects immunocompromised and neutropenic patients.