An unusual Toll/MyD88-mediated Drosophila host defence against Talaromyces marneffei.

Talaromycosis, caused by Talaromyces marneffei (T. marneffei, formerly known as Penicillium marneffei), is an opportunistic invasive mycosis endemic in tropical and subtropical areas of Asia with high mortality rate. Despite various infection models established to study the immunological interaction between T. marneffei and the host, the pathogenicity of this fungus is not yet fully understood. So far, Drosophila melanogaster, a well-established genetic model organism to study innate immunity, has not been used in related research on T. marneffei. In this study, we provide the initial characterization of a systemic infection model of T. marneffei in the D. melanogaster host. Survival curves and fungal loads were tested as well as Toll pathway activation was quantified by RT-qPCR of several antimicrobial peptide (AMP) genes including Drosomycin, Metchnikowin, and Bomanin Short 1. We discovered that whereas most wild-type flies were able to overcome the infection, MyD88 or Toll mutant flies failed to prevent fungal dissemination and proliferation and ultimately succumbed to this challenge. Unexpectedly, the induction of classical Toll pathway activation readouts, Drosomycin and Bomanin Short 1, by live or killed T. marneffei was quite limited in wild-type flies, suggesting that the fungus largely escapes detection by the systemic immune system. This unusual situation of a poor systemic activation of the Toll pathway and a strong susceptibility phenotype of MyD88/Toll might be accounted for by a requirement for this host defence in only specific tissues, a hypothesis that remains to be rigorously tested.

Signals of positive selection in genomes of palearctic Myotis-bats coexisting with a fungal pathogen.

Disease can act as a driving force in shaping genetic makeup across populations, even species, if the impacts influence a particularly sensitive part of their life cycles. White-nose disease is caused by a fungal pathogen infecting bats during hibernation. The mycosis has caused massive population declines of susceptible species in North America, particularly in the genus Myotis. However, Myotis bats appear to tolerate infection in Eurasia, where the fungal pathogen has co-evolved with its bat hosts for an extended period of time. Therefore, with susceptible and tolerant populations, the fungal disease provides a unique opportunity to tease apart factors contributing to tolerance at a genomic level to and gain an understanding of the evolution of non-harmful in host-parasite interactions. To investigate if the fungal disease has caused adaptation on a genomic level in Eurasian bat species, we adopted both whole-genome sequencing approaches and a literature search to compile a set of 300 genes from which to investigate signals of positive selection in genomes of 11 Eurasian bats at the codon-level. Our results indicate significant positive selection in 38 genes, many of which have a marked role in responses to infection. Our findings suggest that white-nose syndrome may have applied a significant selective pressure on Eurasian Myotis-bats in the past, which can contribute their survival in co-existence with the pathogen. Our findings provide an insight on the selective pressure pathogens afflict on their hosts using methodology that can be adapted to other host-pathogen study systems.

Coinfección o sobreinfección fúngica en pacientes con COVID-19 en un hospital de tercer nivel en México.

Introducción. Los datos sobre la prevalencia de coinfecciones o sobreinfecciones fúngicas en pacientes con COVID-19 son limitados. OBJETIVO: Describir la prevalencia de coinfecciones o sobreinfecciones fúngicas en pacientes con COVID-19, así como los factores de riesgo y las características demográficas, clínicas y microbiológicas. Material y métodos. Se incluyeron pacientes con diagnóstico confirmado de COVID-19, hospitalizados en la unidad de cuidados intensivos y con infección fúngica confirmada entre marzo del 2020 y diciembre del 2021. Del expediente clínico se obtuvieron datos sobre edad, sexo, comorbilidades, días de estancia hospitalaria, resultados de laboratorio (ferritina) y microbiológicos, tratamiento contra COVID-19, terapia antifúngica y desenlace. RESULTADOS: Once de 740 pacientes cumplieron con los criterios de inclusión. La tasa de coinfección fue del 0,3 % y la de sobreinfección fue del 1,2 %. La población más afectada fue la de hombres adultos. Las coinfecciones o sobreinfecciones diagnosticadas fueron candiduria y candidemia, causadas por Candida albicans, C. tropicalis, C. glabrata, C. lusitaniae y Kluyveromyces marxianus (C. kefyr). Además, se encontró una traqueobronquitis por Aspergillus fumigatus. Los antifúngicos más administrados fueron fluconazol y caspofungina. La letalidad en pacientes con coinfecciones fue del 50 % y con sobreinfecciones fúngicas, del 22 %. El tiempo de estancia intrahospitalaria fue de 11 a 65 días. Ocho de los pacientes requirieron asistencia respiratoria mecánica y seis recibieron corticoides. La principal comorbilidad fue diabetes mellitus (81,8 %). CONCLUSIONES: La tasa de coinfecciones o sobreinfecciones por hongos en pacientes con COVID-19 fue baja, pero la letalidad de estas requiere, con urgencia, la realización de pruebas de rutina para detectar hongos en pacientes con COVID-19 grave para diagnosticar oportunamente infecciones fúngicas que puedan comprometer aún más la vida del paciente.

[Development of Lomentospora prolificans infection during induction therapy with venetoclax and azacitidine for acute myeloid leukemia].

Lomentospora prolificans is a rare filamentous fungus that causes invasive fungal disease (IFD) in immunocompromised patients with hematological malignancies, as well as hematopoietic cell or solid organ transplant recipients. A 75-year-old woman was diagnosed with acute myeloid leukemia, and started induction therapy with azacitidine and adjusted-dose venetoclax along with antifungal prophylaxis with fluconazole. On day 7, she became febrile and chest CT imaging showed multiple nodules in both lung fields, and the serum galactomannan antigen index became positive, indicating probable IFD. Anti-fungal therapy with liposomal amphotericin B was immediately initiated; however, the patient's condition rapidly deteriorated, and she died on day 15. L. prolificans was later identified in blood culture tests that had been repeatedly performed while she had been febrile. L. prolificans is generally resistant to most antifungal agents, which can make it fatal. As early definitive diagnosis is difficult, it may be appropriate to consider combination therapy when conventional anti-IFD therapy seems inadequate.

Short Tandem Repeat Genotyping of Medically Important Fungi: A Comprehensive Review of a Powerful Tool with Extensive Future Potential.

Fungal infections pose an increasing threat to public health. New pathogens and changing epidemiology are a pronounced risk for nosocomial outbreaks. To investigate clonal transmission between patients and trace the source, genotyping is required. In the last decades, various typing assays have been developed and applied to different medically important fungal species. While these different typing methods will be briefly discussed, this review will focus on the development and application of short tandem repeat (STR) genotyping. This method relies on the amplification and comparison of highly variable STR markers between isolates. For most common fungal pathogens, STR schemes were developed and compared to other methods, like multilocus sequence typing (MLST), amplified fragment length polymorphism (AFLP) and whole genome sequencing (WGS) single nucleotide polymorphism (SNP) analysis. The pros and cons of STR typing as compared to the other methods are discussed, as well as the requirements for the development of a solid STR typing assay. The resolution of STR typing, in general, is higher than MLST and AFLP, with WGS SNP analysis being the gold standard when it comes to resolution. Although most modern laboratories are capable to perform STR typing, little progress has been made to standardize typing schemes. Allelic ladders, as developed for Aspergillus fumigatus, facilitate the comparison of STR results between laboratories and develop global typing databases. Overall, STR genotyping is an extremely powerful tool, often complimentary to whole genome sequencing. Crucial details for STR assay development, its applications and merit are discussed in this review.

Countrywide screening supports model-based predictions of the distribution of Batrachochytrium dendrobatidis in Ukraine.

The chytrid Batrachochytrium dendrobatidis (Bd) is a widespread fungus causing amphibian declines across the globe. Although data on Bd occurrence in Eastern Europe are scarce, a recent species distribution model (SDM) for Bd reported that western and north-western parts of Ukraine are highly suitable to the pathogen. We verified the SDM-predicted range of Bd in Ukraine by sampling amphibians across the country and screening for Bd using qPCR. A total of 446 amphibian samples (tissue and skin swabs) from 11 species were collected from 36 localities. We obtained qPCR-positive results for 33 samples including waterfrogs (Pelophylax esculentus complex) and fire- and yellow-bellied toads (Bombina spp.) from 8 localities. We found that Bd-positive localities had significantly higher predicted Bd habitat suitability than sites that were pathogen-free. Amplification and sequencing of the internal transcribed spacer (ITS) region of samples with the highest Bd load revealed matches with ITS haplotypes of the globally distributed BdGPL strain, and a single case of the BdASIA-2/BdBRAZIL haplotype. We found that Bd was non-randomly distributed across Ukraine, with infections present in the western and north-central forested peripheries of the country with a relatively cool, moist climate. On the other hand, our results suggest that Bd is absent or present in low abundance in the more continental central, southern and eastern regions of Ukraine, corroborating the model-predicted distribution of chytrid fungus. These areas could potentially serve as climatic refugia for Bd-susceptible amphibian hosts.

The yeast also rises! PD-L1 dampens inflammation linked to fungal infections.

Programmed death-ligand 1 interacts with fungal ribosomal Rpl20b in phagosomes and induces interleukin-10 secretion.

Disseminated granulomatous encephalitis caused by Schizophyllum commune in a dog with severe neurological signs.

A 10-year-old spayed mixed breed dog presented with severe neurological signs. Computed tomography revealed a cranial mediastinal mass, osteolysis of the right second rib and second thoracic vertebra, tracheobronchial and mesenteric lymph node enlargement, pneumonia and pleural effusion. Magnetic resonance imaging detected lesions in the white matter of the right frontal lobe and left cerebral hemisphere with contrast-enhanced T1-weighted images showing demarcated enhancement. On cut section, the surface of the right cerebral frontal lobe and left cerebral hemisphere corticomedullary junctions were indistinct and the white matter was discoloured. Microscopically, multicentric granulomatous inflammation was seen in the brain, cranial mediastinal mass, masses on the right second rib, tracheobronchial and mesenteric lymph nodes, heart, kidneys, lungs and oesophagus. Necrosis and hyaline fungal structures were frequently observed in the centre of the granulomas. These fungi had septae, Y-shaped branching and were 2-3 µm in width. Sequence analysis of DNA from formalin-fixed paraffin-embedded samples identified the fungi as Schizophyllum commune. Based on these findings, this case was diagnosed as disseminated S. commune infection. This is the first report of granulomatous encephalitis caused by S. commune in a dog.

The heavy burden and treatment challenges of fungal periprosthetic joint infection: a systematic review of 489 joints.

BACKGROUND: Fungal periprosthetic joint infection (FPJI) is an infrequent but devastating complication that imposes a heavy burden on patients. At present, a consensus regarding the most optimal surgical option for patients with FPJI, the ideal duration of systemic antifungal treatment, and many other issues has not been reached. METHODS: A comprehensive literature search was performed on the PubMed and Embase databases. The search criteria employed were as follows: (fungal OR candida OR mycotic) AND periprosthetic joint infection. Initially, the titles and abstracts were screened, and subsequently, studies deemed irrelevant or duplicative were eliminated. Following this, the complete texts of remaining articles were thoroughly examined. According to the inclusion and exclusion criteria, 489 joints in 24 articles were screened out. We further extracted the demographic characteristics (age, gender, body mass index, etc.), clinical presentation, fungal species, presence of bacterial coinfection, surgical methods, systemic and local antifungal therapy, and treatment outcomes. Subgroup data were analyzed according to fungal species and bacterial coinfection. Univariate logistic regression analysis was conducted to ascertain the risk factors associated with the infection recurrence. RESULTS: A total of 506 fungi were identified within 489 joints. The most prevalent fungal species were Candida albicans (41.5%). Out of 247 joints (50.5%) presenting with concurrent fungal and bacterial infections. Among the initial surgical interventions, two-stage exchange was the most common (59.1%). The infection recurrence rates of DAIR, resection arthroplasty, two-stage, one-stage, and three-stage exchange were 81.4%, 53.1%, 47.7%, 35.0%, and 30%, respectively. The mean duration of systemic antifungal therapy was 12.8 weeks. The most common drugs used both in intravenous (55.9%) and oral therapy (84.0%) were fluconazole. The proportion of patients who used antifungal drugs after replantation (two-stage and three-stage) was 87.6%. 33.2% of cement spacer or fixed cement contained antifungal drugs, of which amphotericin B was the main choice (82.7%). FPJI caused by candida albicans (OR = 1.717, p = 0.041) and DAIR (OR = 8.433, p = 0.003) were risk factors for infection recurrence. CONCLUSIONS: Two-stage exchange remains the most commonly used surgical approach. The reliability of one- and three-exchange needs further evaluation due to the small sample size. Antifungal-loaded cement spacers, and direct intra-articular injections of antimycotics after reimplatation should be strongly considered. Medication is not standardized but rather individualized according to microbiology and the status of patients.

Parasitic and Fungal Triggers of Cytokine Storm Syndrome.

Infections caused by parasites and fungi can trigger the cytokine storm syndrome (CSS). These infections causing CSS can occur together with acquired immunodeficiencies, lymphomas, the use of immunosuppressive medications, transplant recipients, cancer, autoinflammatory, and autoimmune diseases or less frequently in healthy individuals. Histoplasma, Leishmania, Plasmodium, and Toxoplasma are the most frequent organisms associated with a CSS. It is very important to determine a previous travel history when evaluating a patient with a CSS triggered by these organisms as this may be the clue to the causal agent. Even though CSS is treated with specific therapies, an effort to find the causal organism should be carried out since the treatment of the infectious organism may stop the CSS. Diagnosing a CSS in the presence of parasitic or fungal sepsis should also lead to the study of an altered cytotoxic or hemophagocytic response in the susceptible host.

Manipulation of host phagocytosis by fungal pathogens and therapeutic opportunities.

An important host defence mechanism against pathogens is intracellular killing, which is achieved through phagocytosis, a cellular process for engulfing and neutralizing extracellular particles. Phagocytosis results in the formation of matured phagolysosomes, which are specialized compartments that provide a hostile environment and are considered the end point of the degradative pathway. However, all fungal pathogens studied to date have developed strategies to manipulate phagosomal function directly and also indirectly by redirecting phagosomes from the degradative pathway to a non-degradative pathway with the expulsion and even transfer of pathogens between cells. Here, using the major human fungal pathogens Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans and Histoplasma capsulatum as examples, we discuss the processes involved in host phagosome-fungal pathogen interactions, with a focus on fungal evasion strategies. We also discuss recent approaches to targeting intraphagosomal pathogens, including the redirection of phagosomes towards degradative pathways for fungal pathogen eradication.

Allergic Bronchopulmonary Mycosis with Eosinophilia Caused by Schizophyllum Infection.

BACKGROUND: As an opportunistic pathogenic fungus, Schizophyllum has been rarely reported to infect humans. By reporting a case of definite diagnosis of Schizophyllum infection, we aim to improve clinicians' understanding of this bacterium. METHODS: By reporting a case with cough and sputum as the main manifestations, after empirical antiinfective chest CT suggesting a more progressive inflammatory lesion and a mass-like lesion in the paratracheal area of the main airways, a diagnosis of Schizophyllum infection was finally made by bronchoscopy with the delivery of metagenomic next-generation sequencing (mNGS). RESULTS: The patient was finally diagnosed with rare Schizophyllum infection. After antifungal treatment, the symptoms improved, and the patient was discharged. CONCLUSIONS: Although Schizophyllum is a rare fungal infection, it should be taken seriously in patients with diabetes or who are immunocompromised. At the same time, mNGS plays a key role in the detection of rare and emerging pathogens, which is worthy of clinical interest.

Combatting Fungal Infections: Advances in Antifungal Polymeric Nanomaterials.

Fungal pathogens cause over 6.5 million life-threatening systemic infections annually, with mortality rates ranging from 20 to 95%, even with medical intervention. The World Health Organization has recently emphasized the urgent need for new antifungal drugs. However, the range of effective antifungal agents remains limited and resistance is increasing. This Review explores the current landscape of fungal infections and antifungal drugs, focusing on synthetic polymeric nanomaterials like nanoparticles that enhance the physicochemical properties of existing drugs. Additionally, we examine intrinsically antifungal polymers that mimic naturally occurring peptides. Advances in polymer characterization and synthesis now allow precise design and screening for antifungal activity, biocompatibility, and drug interactions. These antifungal polymers represent a promising new class of drugs for combating fungal infections.

The microbial damage and host response framework: lesson learned from pathogenic survival trajectories and immunoinflammatory responses of Talaromyces marneffei infection.

The adverse outcomes of fungal infection in mammalian hosts depend on the complex interactions between the host immune system and pathogen virulence-associated traits. The main clinical problems arise when the host response is either too weak to effectively eliminate the pathogen or overly aggressive, resulting in host tissue damage rather than protection. This article will highlight current knowledge regarding the virulence attributions and mechanisms involved in the dual-sided role of the host immune system in the immunopathogenesis of the thermally dimorphic fungus Talaromyces marneffei through the lens of the damage response framework (DRF) of microbial pathogenesis model.

White adipose tissue remodeling in Little Brown Myotis (Myotis lucifugus) with white-nose syndrome.

White-nose syndrome (WNS) is a fungal wildlife disease of bats that has caused precipitous declines in certain Nearctic bat species. A key driver of mortality is premature exhaustion of fat reserves, primarily white adipose tissue (WAT), that bats rely on to meet their metabolic needs during winter. However, the pathophysiological and metabolic effects of WNS have remained ill-defined. To elucidate metabolic mechanisms associated with WNS mortality, we infected a WNS susceptible species, the Little Brown Myotis (Myotis lucifugus), with Pseudogymnoascus destructans (Pd) and collected WAT biopsies for histology and targeted lipidomics. These results were compared to the WNS-resistant Big Brown Bat (Eptesicus fuscus). A similar distribution in broad lipid class was observed in both species, with total WAT primarily consisting of triacylglycerides. Baseline differences in WAT chemical composition between species showed that higher glycerophospholipids (GPs) levels in E. fuscus were dominated by unsaturated or monounsaturated moieties and n-6 (18:2, 20:2, 20:3, 20:4) fatty acids. Conversely, higher GP levels in M. lucifugus WAT were primarily compounds containing n-3 (20:5 and 22:5) fatty acids. Following Pd-infection, we found that perturbation to WAT reserves occurs in M. lucifugus, but not in the resistant E. fuscus. A total of 66 GPs (primarily glycerophosphocholines and glycerophosphoethanolamines) were higher in Pd-infected M. lucifugus, indicating perturbation to the WAT structural component. In addition to changes in lipid chemistry, smaller adipocyte sizes and increased extracellular matrix deposition was observed in Pd-infected M. lucifugus. This is the first study to describe WAT GP composition of bats with different susceptibilities to WNS and highlights that recovery from WNS may require repair from adipose remodeling in addition to replenishing depot fat during spring emergence.

Marrow talaromycosis as the initial presentation in a case of Burkitt lymphoma.

Talaromyces marneffei is a thermally dimorphic fungus which causes opportunistic infections in immunocompromised individuals. The diagnosis of T. marneffei infection rests on the microscopic demonstration of the fungus in the tissues and/or isolation of the fungus from clinical specimens. In this report, we discuss a case involving a 23-year-old man who presented with a history of intermittent fever, cough and constitutional symptoms. Clinically, the patient exhibited pallor, jaundice, generalized seborrhoeic dermatitis, hepatomegaly, and small palpable cervical lymph nodes. A computed tomography (CT) scan of the abdomen showed homogenous hypodense lesions in both liver lobes. HIV screening result was reactive. Microscopic examination of the bone marrow aspirate smear and trephine biopsy identified fungal bodies, and culture of the marrow aspirate confirmed the presence of T. marneffei. Notably, the liver biopsy revealed Burkitt lymphoma alongside fungal bodies. He was treated with intravenous Amphotericin B but ultimately succumbed to the illness due to severe metabolic acidosis and multiorgan failure. This case underscores the importance of presumptive diagnosis through morphological or histological examination of bone marrow samples, as microbiologic culture methods can be time-consuming. Timely diagnosis and aggressive treatment are critical in managing patients with T. marneffei infection.

Isolated masseter muscle fungal invasion: unmasking the culprit.

This case report focusses on a unique and infrequently observed event where an isolated masseter muscle fungal invasion was seen. The patient's symptoms include facial swelling and restricted mouth opening. The rarity of this particular manifestation is emphasised by the fact that there are no previously reported cases where fungal infection was the cause of isolated masseter muscle involvement. This lack of documented cases underscores the novelty and significance of the current case.

The skin I live in: Pathogenesis of white-nose syndrome of bats.

The emergence of white-nose syndrome (WNS) in North America has resulted in mass mortalities of hibernating bats and total extirpation of local populations. The need to mitigate this disease has stirred a significant body of research to understand its pathogenesis. Pseudogymnoascus destructans, the causative agent of WNS, is a psychrophilic (cold-loving) fungus that resides within the class Leotiomycetes, which contains mainly plant pathogens and is unrelated to other consequential pathogens of animals. In this review, we revisit the unique biology of hibernating bats and P. destructans and provide an updated analysis of the stages and mechanisms of WNS progression. The extreme life history of hibernating bats, the psychrophilic nature of P. destructans, and its evolutionary distance from other well-characterized animal-infecting fungi translate into unique host-pathogen interactions, many of them yet to be discovered.

Stable in vitro fluorescence for enhanced live imaging of infection models for Batrachochytrium dendrobatidis.

Realistic and modifiable infection models are required to study the pathogenesis of amphibian chytridiomycosis. Understanding the mechanism by which Batrachochytrium dendrobatidis (Bd) can infect and kill diverse amphibians is key to mitigating this pathogen and preventing further loss of biodiversity. In vitro studies of Bd typically rely on a tryptone based growth media, whereas the recent development of a kidney cell-line infection model has provided a more realistic alternative, without the need for live animals. Here we use expression of a fluorescent reporter to enhance the in vitro cell-line based growth assay, and show that transformed Bd cells are able to invade and grow in an amphibian kidney epithelial cell line (A6) as well as in a new system using a lung fibroblast cell line (DWJ). Both Bd and host cells were modified to express reporter fluorescent proteins, enabling immediate and continuous observation of the infection process without the need for destructive sampling for fixation and staining. Plasmid DNA conferring hygromycin resistance and TdTomato (RFP) expression was delivered to Bd zoospores via electroporation, and continuous antibiotic selection after recovery produced stable fluorescent Bd transformants. Host cells (A6 and DWJ) were transfected before each assay using lipofection to deliver plasmid DNA conferring green fluorescent protein (GFP) and containing an empty shRNA expression cassette. Bd RFP expression allowed easy localisation of fungal cells and identification of endobiotic growth was assisted by host GFP expression, by allowing visualization of the space in the host cell occupied by the invading fungal body. In addition to enabling enhanced live imaging, these methods will facilitate future genetic modification and characterisation of specific genes and their effect on Bd virulence.