Dimorphic Fungus Research Articles

Analysis of public health risks associated with pathogenic fungi in China

At present, the public health risks caused by pathogenic fungi are greater in China and have attracted great attention from disease control departments. Due to the difficulty in diagnosing fungal infections, the public health risk of pathogenic fungi is currently hidden in the unexplained pneumonia/encephalitis/fever syndrome and is not effectively appreciated. From the public health perspective, the mainly focused fungal pathogens include highly pathogenic fungi (including dimorphic fungi and dematiaceous fungi), pathogenic fungi that cause regional aggregation infections, and drug-resistant pathogenic fungi. However, due to the lack of systematic monitoring data, the disease burden related to pathogenic fungi cannot be accurately quantified and evaluated. Therefore, to effectively reduce the serious harm of fungal infections to the public, systematic monitoring of pathogenic fungi should be carried out nationally.

Comparative investigations into the growth details of Histoplasma capsulatum var farciminosum on four different agar media.

Epizootic equine lymphangitis (EEL) is a chronic fungal disease that affects equids. The causative agent is a dimorphic fungus called Histoplasma capsulatum var farciminosum. H. capsulatum var farciminosum field strain 7 (D 2878/2023) isolated from the eye socket of an EEL Ethiopian horse was sub-cultured on 4 different solid media and incubated at 26°C and 37°C for 6 weeks. Details of growth morphology were recorded and shown in images during 6 weeks of incubation. H. capsulatum var farciminosum grew best at 26°C on all 4 agars, but only on sheep blood agar at 37°C as small, white dry colonies.

Identification of B- cell and T- cell specific peptide vaccine for Histoplasma capsulatum

Histoplasma capsulatum is an environmental dimorphic fungus. H. capsulatum infections are primarily acquired, and there is no person-to-person transmission with the rare exception of organ transplantation. The objective of this research is to identify a B-cell and T-cell specific peptide vaccine for H. capsulatum by analyzing the outer membrane protein, predicting B-cell and T-cell epitopes, and selecting a candidate peptide vaccine with high homology to the pathogen and strong MHC I-binding potential

A rare case of Disseminated Histoplasmosis with Hemophagocytic Lymphohistiocytosis mimicking a flare of Systemic Lupus Erythematosus in a middle-aged man: A Case Report

Abstract Introduction/Objective Disseminated histoplasmosis is a progressive granulomatous disease caused by Histoplasmosis capsulatum which is an intracellular dimorphic fungus endemic to Ohio and Mississippi River valleys in the United States. The progressive spread of the infection to organs is thought to be due to the failure of the activation of the T-cell mediated immune response. Hemophagocytic lymphohistiocytosis is a rare but potentially fatal condition in which histiocytes and lymphocytes build up in and damage organs and other blood cells. Diagnosing Disseminated Histoplasmosis with Hemophagocytic Lymphohistiocytosis in a patient with Systemic Lupus Erythematosus is diagnostically challenging due to the rare presentation. Hence, we are reporting this case to alert physicians to keep a high index of suspicion in such presentations. Methods/Case Report We present a 37-year-old man with a past medical history of Systemic Lupus Erythematosus complicated by Lupus Nephritis on immunosuppressive therapy who presented to the emergency department with hypotension and was admitted for acute kidney injury. Prior to the presentation, he had persistent fever, myalgias, cough, mild shortness of breath, and back pain. CT Chest shows “eggshell” calcification and further parasitology evaluation revealed a diagnosis of histoplasmosis using a blood sample where intracellular Histoplasma organisms were identified. A diagnosis of Hemophagocytic lymphohistiocytosis was made clinically after “Clinical and Testing Criteria” was evaluated. Despite further management, he developed coagulopathy and sepsis which led to his death. Results (if a Case Study enter NA) At autopsy, we found organomegaly of the liver, spleen, and kidneys. Microscopically, these enlarged organs show old fibrotic granulomas and granulomatous inflammation with suspected fungal organisms. Periodic Acid Schiff (Fungus) and Gomori's Methenamine Silver special stain confirm these fungal organisms to be consistent with Histoplasma species (3-5 micron budding yeasts). Conclusion This case report highlights that physicians should be aware of the diagnostic challenge that Disseminated Histoplasmosis with Hemophagocytic Lymphohistiocytosis could pose in patients with Systemic Lupus Erythematosus, especially those on immunosuppression. The clinical presentation could easily mimic a flare of Systemic Lupus Erythematosus, leading to more aggressive immunosuppression. Failure to recognize the infection promptly could lead to grievous complications and sometimes death.

Disseminated histoplasmosis diagnosed on peripheral blood smear: a case report

Abstract Introduction/Objective Histoplasmosis is an infection caused by the inhalation of a dimorphic fungus, Histoplasma capsulatum. H. Capsulatum var capsulatum is the main variety we encounter in the United States and is endemic in the Mississippi river valley. In immunocompetent individuals the infection is usually asymptomatic or presents as flu- like symptoms. Disseminated histoplasmosis is a severe and often fatal opportunistic infection if not treated, usually seen in immunocompromised patients. Methods/Case Report We report a case of a 27-year-old female intra-venous drug user with past medical history of untreated HIV diagnosed in 2018, who is being admitted for suspected necrotizing fasciitis of the vulva. On admission, her complete blood count shows pancytopenia with a white blood cell count of 2.9 × 109/L (NR 4.3-10.8 × 109/L), hemoglobin 6.1 g/dL (NR 12-16 g/dL), and a platelet count of 43 × 109/L (NR 150-400 × 109/L). A peripheral blood smear obtained showing rare neutrophils with intracellular organism highly suggestive of histoplasma capsulatum. CT Chest showing diffuse ground glass opacities and a subsequent cytology from bronchoalveolar lavage performed revealed numerous macrophages filled with ovoid organism surrounded by a cytoplasmic halo, GMS stain highlights the rim consistent with histoplasma capsulatum. Patient expired after one week in the ICU for severe acute respiratory distress syndrome, sepsis, histoplasmosis, strep pneumonia and hepatic failure. Results (if a Case Study enter NA) NA Conclusion Careful examination of Peripheral blood smear along with correct clinical history can aid in early diagnosis of disseminated histoplasmosis.

819. Experience with Isavuconazole Use for Treatment of Invasive Fungal Infections

Abstract Background The treatment of invasive fungal infections (IFI) is often complicated by drug-drug interactions, toxicities, and host comorbidities. Isavuconazole (ISA) has a favorable side effect profile and has FDA approval for invasive aspergillosis and mucormycosis, but there are fewer data on its efficacy for other microbes and non-pulmonary infections. We report our experience of ISA in IFI treatment, with a particular focus on non-pulmonary sites and other microbial etiologies. Methods We identified patients who received ISA as part of IFI treatment from 1/1/2015–4/1/2020 at Mayo Clinic. We categorized them by organ involvement and by pathogens, and identified patterns of ISA use and clinical outcomes. Results A total of 131 patients were identified. Similar to the existing literature, the majority were pulmonary infections (60%), with 12% invasive sinus infection, 12% central nervous system (CNS) infection, and 7% fungemia. Aspergillus was the most common pathogen (39%), yeast comprised 19%, dimorphic fungi 15%, Mucormycosis 12%, phaeohyphomycosis 5%, and other molds 3%. ISA was used as secondary/salvage therapy in 89% of cases. The response rate varied by organ involvement and pathogen. ISA had complete/partial resolution or achieved stability in 57% of fungemia cases, 63% of invasive sinus infections, 64% of pulmonary infections, and 73% of CNS infections. Aspergillus species had a 67% response rate, with 72% response in yeast infections, 65% rate in dimorphic fungi, 53% for mucormycosis, and 86% in dematiaceous molds. Conclusion Although limited by a small sample size, the subgroup review based on organ site and microbial etiology did seem to show roughly similar results to approved uses. The CNS infections treated with ISA were particularly of interest, given the limited options available with reliable CNS penetration. The current available literature has little to say on the efficacy of ISA in these off-label uses, with the majority being similar case series. This report highlights the importance of prospective trials comparing ISA to other antifungals in a greater variety of indications to better identify when this better-tolerated agent can be safely used. Disclosures Courtney E. Harris, MD, Dynamed: Advisor/Consultant

2108. In-vitro Activity of Five Novel Anti-Fungal Compounds Against Thirty-Two Strains of Talaromyces marneffei

Abstract Background Talaromyces marneffei (Tm) is a thermally dimorphic fungus causing invasive mycosis in human immunodeficiency virus (HIV) infected patients in Southeast Asia and is a leading cause of AIDS-related deaths in this region with mortality on anti-fungal therapy as high as 30%. The limited options, routes of administration, and toxicity of antifungals with established efficacy against Tm calls for assessment of efficacy for additional antifungals against Tm. Here we evaluate the in-vitro efficacy of 5 novel anti-fungal agents against 32 clinical strains of Tm. The agents tested include ibrexafungerp, two manogepix compounds (APX001A and APX2039), olorofim, and oteseconazole. Methods 32 Tm isolates were cultured from clinical samples from patients in Vietnam and identified as Tm by standard morphological characteristics. Inocula were prepared from these clinical samples in conjunction with CLSI standards and plated onto 96-well microplates. Concentrations for each drug ranged from 0.008 µg/mL to 4 µg/mL. AlamarBlueTM, a resazurin-based cell viability indicator dye, was added to the drug-inoculum solution. Use of this reagent enabled utilization of a microplate fluorescence intensity(FI) reader to objectively identify the designated MIC endpoint of 50% inhibition of growth. Methods (Figure 1). MIC endpoint determination using AlamarBlue indicator dye method. Clinical Tm isolates were thawed and plated on Yeast Peptone Dextrose (YPD) agar and grown for 3-5 days at 37°C. Isolates were then sub-cultured on fresh YPD agar and allowed to grow for 3 days prior to inoculum preparation. Inocula were prepared according to CLSI standards. Following suspension in solution, inocula were diluted in PBS until an optical density (OD) of 0.5 to 0.6 was achieved. Inocula were further diluted in RPMI + MOPS and added to the drug-dilution microplates to achieve a final concentration of 1000-5000 cells/mL. After incubation at 37°C for 24 hours, AlamarBlue was added to all wells. Following incubation for an additional 48 hours, fluorescence intensity (FI) was measured using a microplate reader to determine the MIC endpoint of 50% inhibition of fungal growth. Results Of the drugs tested, olorofim showed the highest activity against the 32 isolates, with MICs consistently ≤ 0.008 µg/mL. This was followed by oteseconazole with MICs between ≤ 0.008 and 0.031 µg/mL APX001A with MICs between 0.031 and 0.25 µg/mL and APX2039 with MICs between 0.25 and 4 µg/mL. Ibrexafungerp had the broadest MIC distribution with MICs between 0.063 and 4 µg/mL. Figure 2/Table 1. MIC Endpoint Distribution. Figure 2 shows a scatter plot of MIC endpoints for each drug. Error bars demonstrate the geometric mean and 95% confidence intervals. Table 1 illustrates the MIC endpoint distribution in a graded heat map format. In addition, the absolute values of the geometric mean (GM), mode, MIC50, and MIC90 are displayed at the right side of the table. Both Figure 2 and Table 1 illustrate high efficacy for olorofim and oteseconazole, with low MIC endpoints consistent across the 32 isolates. The manogepix compounds(APX001A and APX2039) demonstrate surprisingly contrasted performance against Tm, despite the similar chemical structure and identical mechanism of action of the drugs. APX001A had significantly lower MIC endpoints compared to APX2039. Ibrexafungerp had the broadest range of MIC endpoints from 0.063 to 4µg/mL and the highest MIC50 and MIC90 of all the drugs. However, a significant proportion of isolates were highly susceptible to the drug. Conclusion In-vitro activity of the 5 drugs tested against the 32 Tm strains was variable, but all should be considered potential candidates for treating Tm infection. To further evaluate the potential role of each drug in treating Tm infection, the next step should be to evaluate each in in-vivo models. Disclosures All Authors: No reported disclosures

2516. Development of a de novo Patient-Reported Outcome (PRO) Measure to Assess the Impacts of Disseminated Coccidioidomycosis [Valley Fever] on Patients Living with the Condition

Abstract Background Extrapulmonary or disseminated coccidioidomycosis (cocci) is a rare, severe form of fungal disease acquired by inhaling spores of Coccidioides spp., a dimorphic fungus endemic in the southwest United States (US) and parts of Central/South America. Currently, there are no measures that assess the patient experience of health-related quality of life (HRQL) impacts associated with disseminated cocci. Preliminary work to develop a disease-specific PRO has been completed (i.e., literature review, conceptual model development [fig 1], clinician interviews). The focus of this research was to gather qualitative evidence directly from patients living with disseminated cocci. Initial draft of a Patient-Centered Conceptual Model of Coccidioidomycosis A conceptual model of the symptoms and impacts of coccidioidomycosis was developed by analyzing 29 online patient stories after a literature review revealed qualitative, patient experience research was nonexistent in fungal infections. Methods Concept elicitation (CE) interviews were conducted with 25 patients with chronic, symptomatic disseminated cocci. Audio recordings of 60–110-minute telephone interviews were transcribed and qualitatively analyzed using NVivo 1.6. Saturation analysis was performed to determine if all concepts had emerged such that additional interviews would not add to the findings. Item generation meetings were then held between F2G, COS and a patient advocate to develop draft items reflecting the HRQL impacts of the condition. Results Thirteen (52.0%) CNS/multi-site and 12 (48.0%) non-CNS/multi-site patients participated; 18 (72.0%) were English-speakers and 7 (28.0%) were native Spanish-speakers; 3 (12.0%) were Black and 12 (48.0%) were Hispanic. Key impacts were identified across 5 domains, all reaching saturation (fig 2,3): physical function (physical activity, walking, climbing stairs, standing), activities of daily living (household chores, self-care), cognitive function (memory, focus), social-role impacts (work/school, socializing) and emotional (depression, anxiety). No major differences were found between CNS/non-CNS and English/Spanish patient experiences. Physical function and ADL Impacts Reported by Patients with Disseminated Cocci: Subgroup Analyses 1 CE interview results showed disseminated patients were significantly impacted in their physical functioning and activities of daily living. A surprising result was that in general, CNS and non-CNS patients had similar impact experiences as a result of disseminated cocci. (Total number of patients who experienced the impact is shown at the top of the column and the number of patients within each subgroup who experienced the impact is shown within the column). Social/Role, Emotional and Cognitive Impacts Reported by Patients with Disseminated Cocci: Subgroup Analyses 2 Disseminated patients were also affected socially, cognitively and emotionally, as well as in their roles professionally, and as caregivers and providers. Impact on communication consisted of difficulty retrieving words and following conversation. Cognitive impacts experienced by non-CNS patients were more prevalent than anticipated. Conclusion The CE interviews provided rich qualitative data on symptom and impact experiences of patients with disseminated cocci. The findings were used to draft a disease-specific PRO measure assessing HRQL impacts of disseminated cocci, consisting of 19 items across 5 domains (fig 4). Cognitive debrief interviews are now planned with disseminated cocci patients and clinicians to further evaluate the validity of the measure. Hypothesized Conceptual Framework of PRO measure 'Patient-Reported Impacts of Disseminated Coccidioidomycosis (Valley Fever)' Conceptual frameworks represent how a PRO measure may generate a score, broadly illustrating which patient experiences will be measured and how they will be measured. Disclosures Emma L. Harvey, BSc, MBBS, MRCP, FFPM, F2G Ltd: Employee|F2G Ltd: Stocks/Bonds Mark Bresnik, MD, F2G, Ltd.: Stocks/Bonds Elliott Blatt, MPH, F2G Ltd: Advisor/Consultant Rob Purdie, n/a, Clinical Outcomes Solutions: Consulting

Volatile Fingerprint Mediates Yeast-to-Mycelial Conversion in Two Strains of Beauveria bassiana Exhibiting Varied Virulence.

Beauveria bassiana is a dimorphic and entomopathogenic fungus with different ecological roles in nature. In pathogenic fungi, yeast-to-mycelial conversion, which is controlled by environmental factors, is required for virulence. Here, we studied the effects of different stimuli on the morphology of two B. bassiana strains and compared the toxicities of culture filtrates. In addition, we explored the role of volatiles as quorum sensing-like signals during dimorphic transition. The killing assays in Caenorhabditis elegans (Nematoda: Rhabditidae) showed that strain AI2 isolated from a mycosed insect cadaver had higher toxicity than strain AS5 isolated from soil. Furthermore, AI2 showed earlier yeast-to-mycelial switching than AS5. However, an increase in inoculum size induced faster yeast-to-mycelium conversion in AS5 cells, suggesting a cell-density-dependent phenomenon. Gas chromatography-mass spectrometry (GC-MS) analyses showed that the fingerprint of the volatiles was strain-specific; however, during the morphological switching, an inverse relationship between the abundance of total terpenes and 3-methylbutanol was observed in both strains. Fungal exposure to 3-methylbutanol retarded the yeast-to-mycelium transition. Hence, this study provides evidence that volatile compounds are associated with critical events in the life cycle of B. bassiana.

Transcriptional Response of Candida albicans to Nanostructured Surfaces Provides Insight into Cellular Rupture and Antifungal Drug Sensitization.

The rise in resistance levels against antifungal drugs has necessitated the development of strategies to combat fungal infections. Nanoscale antimicrobial surfaces, found on the cuticles of insects, have recently emerged as intriguing alternative antifungal strategies that function passively via contact and induced cell rupture. Nanostructured surfaces (NSS) offer a potentially transformative antimicrobial approach to reducing microbial biofilm formation. We examined the transcriptional response of Candida albicans, an opportunistic pathogen that is also a commensal dimorphic fungus, to the NSS found in the wings of Neotibicen spp. cicada and found characteristic changes in the expression of C. albicans genes associated with metabolism, biofilm formation, ergosterol biosynthesis, and DNA damage response after 2 h of exposure to the NSS. Further validation revealed that these transcriptional changes, particularly in the ergosterol biosynthesis pathway, sensitize C. albicans to major classes of antifungal drugs. These findings provide insights into NSS as antimicrobial surfaces and as a means of controlling biofilm formation.

In vitro manogepix susceptibility testing of South African Emergomyces africanus, Emergomyces pasteurianus, and Blastomyces emzantsi clinical isolates.

We performed in vitro antifungal susceptibility testing of manogepix against the yeast phase of 78 Emergomyces africanus, 2 Emergomyces pasteurianus, and 5 Blastomyces emzantsi isolates using a reference broth microdilution method following Clinical and Laboratory Standards Institute recommendations. All three pathogens had low minimum inhibitory concentrations ranging from <0.0005 to 0.008 mg/L. Manogepix should be investigated in animal models and potentially in future human clinical trials for endemic mycoses.

Development and validation of a colorimetric antifungal susceptibility testing method for the dimorphic fungus Talaromyces marneffei.

Antifungal drug resistance is an emerging cause of treatment failure in invasive fungal infections, and antifungal susceptibility testing (AFST) may inform treatment decisions. Currently, there are no established AFST guidelines for Talaromyces marneffei (Tm) or other dimorphic fungi. We developed a colorimetric AFST method using a fluorescent redox indicator alamarBlue, which changes from blue to pink in proportion to cellular metabolic activity. We determined the optimal time for alamarBlue addition to be 24h post-inoculation and for MIC reading to be 72h post-inoculation. Our method allows three ways to determine minimum inhibitory concentration (MIC): visual inspection of color change, optical density, and fluorescence intensity. We validated the assay by determining the MICs for seven antifungals against 32 Tm clinical isolates and assessed the essential agreement (EA) and inter-rater reliability between our alamarBlue and the Clinical Laboratory Standard Institute (CLSI) broth microdilution methods. The MIC ranges (from low to high) were: 0.008-0.025 μg/ml for itraconazole, 0.004-0.13 μg/ml for voriconazole, 0.03-0.13μg/ml for posaconazole, 0.06-0.5µg/ml for flucytosine, 0.5-1µg/ml for amphotericin B, 0.5-4µg/ml for caspofungin, and 0.5-16µg/ml for fluconazole. The EAs were 100% between all three MIC readouts of the alamarBlue method, and 94%-100% between the alamarBlue and CLSI methods. Our alamarBlue method had substantially higher inter-rater agreement and offers a more reliable method that can be standardized across laboratories in both high- and low-resource settings compared to the established CLSI methodology.

Invasive Malassezia Infections.

The Malassezia species are dimorphic fungi that require lipids such as olive oil for their growth. They are constituents of the normal human skin microbiota and can affix to the host or other surfaces through the establishment of biofilms. Malassezia species are accountable for superficial mycoses like folliculitis. Additionally, they are capable of causing invasive infections, such as of the bloodstream, in neonates and immunocompromised patients, albeit infrequently. Catheter-associated bloodstream infections in neonates are the most commonly reported invasive cases. Remarkably, unlike other invasive fungal infections, neutropenia and the use of broad-spectrum antibiotics do not seem to contribute to the risk of invasive Malassezia infections. Nosocomial outbreaks of Malassezia infections have been reported. While most cases of invasive Malassezia infection are fungemia, they seldom give rise to disseminated lesions in various organs. The diagnosis can be confirmed by the visualization of characteristic yeasts through histologic or cytologic examination of a biopsy or needle aspiration specimen, or via positive culture results from sterile sites. The prognosis for invasive Malassezia infection is generally favorable, with few reports of treatment failure. Nevertheless, due to the limited number of cases, evidence-based treatment recommendations are wanting. Management of invasive Malassezia infections linked to central venous catheters includes removal of the catheter, cessation of intravenous lipid emulsion, and intravenous administration of appropriate antifungal agents.

Identification and production of novel potential pathogen-specific biomarkers for diagnosis of histoplasmosis.

Immunological assays based on the detection of circulating fungal biomarkers are helpful in clinical practice for diagnosing invasive fungal infections. Some of these targeting antigenic components are common to several different fungi. Histoplasmosis is a mycosis caused by the dimorphic fungus Histoplasma capsulatum, which in recent years has gained significant relevance due to the increase in the population susceptible to developing severe clinical forms, including those living with HIV/AIDS. Immunological tests that detect cell wall polysaccharide antigens are among the most used laboratory techniques for diagnosing this mycosis. However, none have shown adequate performance, and cross-reactivity with other fungal pathogens may be observed. Considering that there is a real need to improve the sensitivity and specificity of current diagnostic methods, we explored a novel strategy for the identification of H. capsulatum-specific antigens (Hc_Ags) that could be detected in clinical samples during infection based on a computational analysis model that included the application of bioinformatics tools and the analysis of experimental data from transcriptomics and proteomics. The Hc_Ags identified were expressed and purified by eukaryotic and prokaryotic systems. First, the Hc_Ags were used in an in-house immunization model in mice (BALB/c) to obtain Hc_Ag-specific polyclonal antibodies (Hc_Ag_PAb). Then, the presence of these antigens in H. capsulatum-yeast culture extracts and the specificity of Hc_Ag_PAb against culture extracts of Candida albicans, Aspergillus fumigatus, Cryptococcus neoformans, Fusarium spp., and Paracoccidioides brasiliensis were confirmed. Finally, we demonstrated the immunoreactivity of these Hc_Ag-specific polyclonal antibodies with urine samples from patients previously diagnosed with histoplasmosis.IMPORTANCEHistoplasmosis is considered one of the most important mycoses due to the increasing number of individuals susceptible to develop severe clinical forms, particularly those with HIV/AIDS or receiving immunosuppressive biological therapies, the high mortality rates reported when antifungal treatment is not initiated in a timely manner, and the limitations of conventional diagnostic methods. In this context, there is a clear need to improve the capacity of diagnostic tools to specifically detect the fungal pathogen, regardless of the patient's clinical condition or the presence of other co-infections. The proposed novel pathogen-specific biomarkers have the potential to be used in immunodiagnostic platforms and antifungal treatment monitoring in histoplasmosis. In addition, the bioinformatics strategy used in this study could be applied to identify potential diagnostic biomarkers in other models of fungal infection of public health importance.

The Yeast and Hypha Phases of Candida krusei Induce the Apoptosis of Bovine Mammary Epithelial Cells via Distinct Signaling Pathways.

Infection with Candida spp. is a significant cause of bovine mastitis globally. We previously found that C. krusei was the main pathogen causing mycotic mastitis in dairy cows in Yinchuan, Ningxia, China. However, whether the infection of this pathogen could induce apoptosis in BMECs remained unclear. In this report, we explored the apoptosis and underlying mechanism of BMECs induced by C. krusei yeast and hypha phases using a pathogen/host cell co-culture model. Our results revealed that both the yeast and hypha phases of C. krusei could induce BMEC apoptosis; however, the yeast phase induced more cell apoptosis than the hypha phase, as assessed via electronic microscopy and flow cytometry assays. This finding was further corroborated via the measurement of the mitochondrial membrane potential (MMP) and the TUNEL test. Infection by both the yeast and hypha phases of C. krusei greatly induced the expression of proteins associated with cell death pathways and important components of toll-like receptor (TLR) signaling, including TLR2 and TLR4 receptors, as determined via a Western blotting assay. BMECs mainly underwent apoptosis after infection by the C. krusei yeast phase through a mitochondrial pathway. Meanwhile, BMEC apoptosis induced by the C. krusei hypha phase was regulated by a death ligand/receptor pathway. In addition, C. krusei-induced BMEC apoptosis was regulated by both the TLR2/ERK and JNK/ERK signaling pathways. These data suggest that the yeast phase and hypha phase of C. krusei induce BMEC apoptosis through distinct cell signaling pathways. This study represents a unique perspective on the molecular processes underlying BMEC apoptosis in response to C. krusei infection.

Closing the Gap in Proteomic Identification of Histoplasma capsulatum: A Case Report and Review of Literature.

Histoplasmosis is a globally distributed systemic infection caused by the dimorphic fungus Histoplasma capsulatum (H. capsulatum). This fungus can cause a wide spectrum of clinical manifestations, and the diagnosis of progressive disseminated histoplasmosis is often a challenge for clinicians. Although microscopy and culture remain the gold standard diagnostic tests for Histoplasma identification, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has emerged as a method of microbial identification suitable for the confirmation of dimorphic fungi. However, to our knowledge, there are no entries for H. capsulatum spectra in most commercial databases. In this review, we describe the case of disseminated histoplasmosis in a patient living with HIV admitted to our university hospital that we failed to identify by the MALDI-TOF method due to the limited reference spectrum of the instrument database. Furthermore, we highlight the utility of molecular approaches, such as conventional polymerase chain reaction (PCR) and DNA sequencing, as alternative confirmatory tests to MALDI-TOF technology for identifying H. capsulatum from positive cultures. An overview of current evidence and limitations of MALDI-TOF-based characterization of H. capsulatum is also presented.

Laryngeal coccidioidomycosis in adults: systematic review of the literature and a case report

Abstract BACKGROUND. Coccidioidomycosis spp. is a dimorphic fungus endemic to the southwestern United States and northern Mexico. Incidences in high-risk locations have increased over the last years. MATERIAL AND METHODS. A systematic review has been carried out following the PRISMA guidelines of the reports found in PubMed, Scopus, Google Scholar databases from 1953 to 2023. We included articles written in the English language, with the following keywords “laryngeal” and “coccidioidomycosis” and “adults”, "upper respiratory tract" and "coccidioidomycosis" and "adults". RESULTS. In the review, we could access 8 publications with a total of 10 cases in which 7 men and 3 women were reported, with a mean age of 49.3 years. The ten reported cases were from the southern region of the United States, which borders our state of Sonora in the north. Also, we report the case of a 24-year-old male patient, who presented a chronic picture of more than 1 year with dysphonia, worsening in the last month. He underwent direct laryngoscopy with biopsy, resulting in the diagnosis of laryngeal coccidioidomycosis. Our patient had multiple comorbidities, among which chronic kidney disease in treatment with peritoneal dialysis, erythropoietin and prednisone, with a history of renal transplant in 2017, rejected in 2019. CONCLUSION. Laryngeal coccidioidomycosis is a diagnostic challenge for the clinician, its characteristics may appear to be a malignant entity, up to the formation of abscesses and even present bone destruction. The geographical area in which we are located makes it necessary to always include coccidioidomycosis as a pathology to rule out in our patients.

A Rare Case of Exophiala Werneckii Retinochoroiditis

Exophiala is a rare fungal organism causing a variety of ophthalmic manifestations, including keratitis, scleritis, and endophthalmitis. In this report, we present a rare case of a 51-year-old female who presented as retinochoroiditis. A pigmented, dimorphic fungus known as Exophiala werneckii was isolated from the aqueous and vitreous samples of the patient. The patient underwent multiple injections of intravitreal voriconazole, following which she improved clinically. This case report demonstrates a unique presentation of this rare causative organism.

Polypeptides Targeting Paracoccidioides brasiliensis Drk1.

Considering the toxicity of conventional therapeutic approaches and the importance of precise mechanistic targets, it is important to explore signaling pathways implicated in fungal pathobiology. Moreover, treatment of paracoccidioidomycosis, a systemic mycosis caused by a dimorphic fungus, requires prolonged therapeutic regimens. Among the numerous factors underpinning the establishment of Paracoccidioides spp. infection, the capacity to transition from the mycelial to the yeast form is of pivotal importance. The Drk1 protein of Paracoccidioides brasiliensis likely plays a decisive role in this morphological shift and subsequent virulence. We identified peptides with affinity for the PbDrk1 protein using the phage-display method and assessed the effects of these peptides on P. brasiliensis. The peptides were found to inhibit the phase transition of P. brasiliensis. Furthermore, a substantial proportion of these peptides prevented adhesion to pneumocytes. Although these peptides may not possess inherent antifungal properties, they can augment the effects of certain antifungal agents. Notably, the cell wall architecture of P. brasiliensis appears to be modulated by peptide intervention, resulting in a reduced abundance of glycosylated proteins and lipids. These peptides were also evaluated for their efficacy in a Galleria mellonella model and shown to contribute to enhanced larval survival rates. The role of PbDrk1, which is notably absent in mammals, should be further investigated to improve the understanding of its functional role in P. brasiliensis, which may be helpful for designing novel therapeutic modalities.

Histoplasmosis: An epidemiological and clinical update in China, review and a case report

ABSTRACT Histoplasmosis is a systemic mycosis caused by the dimorphic fungus in the genus Histoplasma. Histoplasmosis is overlooked in China. This study aims to provide an epidemiological and clinical update on histoplasmosis in China by literature review. We reviewed cases of histoplasmosis reported in recent 11 years and described a case of histoplasmosis-triggered hemophagocytic lymphohistiocytosis (HLH) in an immunocompetent patient. A total of 225 cases of histoplasmosis diagnosed in China between 2012 and 2022 were involved in this study, compared with 300 cases reviewed from 1990 to 2011, an increasing number of cases of histoplasmosis have been diagnosed in the last 11 years. The majority of cases of histoplasmosis were autochthonous cases, mainly from provinces Sichuan (56/225, 24.9%), Hunan (50/225, 22.2%), Guangdong (31/225, 13.8%), and Yunnan (24/225, 10.7%). Higher incidence (52.5%, 53/99) of histoplasmosis occurred in immunocompetent patients which is similar to those from the previous 21 years, and the prevalence of the disease did not vary highly over time. Of note, the number of histoplasmosis cases is increasing, and the geographic distribution is shifting southwards over time. Improved awareness is critically important for informing clinical practice in China.