Evaluation of commercial immunodiffusion reagents for detecting serum anti-Paracoccidioides antibodies.

BACKGROUND: Accurate diagnosis of paracoccidioidomycosis is crucial for improving patient outcomes. Paracoccidioides antibody detection by double immunodiffusion (DID) is a convenient diagnostic tool, but testing performance can vary based on certain factors. METHODS: We assessed DID performance using a commercially prepared Paracoccidioides reagents (IMMY, USA), involving 40 serum specimens, including 20 from patients with proven paracoccidioidomycosis and 20 from patients without the disease. The DID test demonstrated a sensitivity of 90% (95% CI=68%-99%) and a specificity of 100% (95% CI=83%-100%). CONCLUSIONS: Our findings suggest that DID using commercial reagents may provide a feasible tool with satisfactory testing performance for anti-Paracoccidioides antibody detection.

Carbon nanoparticle-based lateral flow assay for the detection of specific double-tagged DNA amplicons of Paracoccidioides spp.

To overcome the limitations of current methods for diagnosing paracoccidioidomycosis (PCM), it is critical to develop novel diagnostic strategies that can be implemented in low-resource settings and dramatically improve turnaround times. This study focused on the development of a portable molecular test to screen for Paracoccidioides spp. The proposed approach integrated double-tagging polymerase chain reaction (PCR) and a paper-based lateral flow assay (LFA) for readout, using carbon nanoparticles as a signal generation system. Primers tagged with biotin and digoxigenin were employed to conduct the double-tagging PCR, which can be conveniently carried out on portable thermocyclers. This method can generate billions of tagged DNA copies from a single target molecule, which can be rapidly detected by the LFA platform, providing results within minutes. Avidin-modified carbon nanoparticles served as a signal generation system, enabling detection in the immunochromatographic assay. The LFA demonstrated the capability to detect double-tagged amplicons as low as 0.21 ng or 0.10 ng, depending on whether the results were assessed visually or with a smartphone equipped with an image processor. These findings suggest that the proposed approach holds great promise as a point-of-care diagnostic tool for the early and accurate detection of PCM in low-resource settings. The diagnostic test is rapid and inexpensive, requires minimal handling and can be easily introduced into the general practitioner's armoury for ambulatory screening of infection. This innovative approach has the potential to make a substantial contribution to PCM diagnosis, ultimately reducing morbidity and mortality associated with this disease.

Extracellular vesicles from virulent P. brasiliensis induce TLR4 and dectin-1 expression in innate cells and promote enhanced Th1/Th17 response.

Extracellular vesicles (EVs) are membrane-enclosed nanoparticles that transport several biomolecules and are involved in important mechanisms and functions related to the pathophysiology of fungal diseases. EVs from Paracoccidioides brasiliensis, the main causative agent of Paracoccidioidomycosis (PCM), modulate the immune response of macrophages. In this study, we assessed the EVs proteome from a virulent P. brasiliensis isolated from granulomatous lesions and compared their immunomodulatory ability with EVs isolated from the fungus before the animal passage (control EVs) when challenging macrophages and dendritic cells (DCs). Proteome showed that virulent EVs have a higher abundance of virulence factors such as GP43, protein 14-3-3, GAPDH, as well as virulence factors never described in PCM, such as aspartyl aminopeptidase and a SidJ analogue compared with control EVs. Virulent extracellular vesicles induced higher expression of TLR4 and Dectin-1 than control EVs in macrophages and dendritic cells (DCs). In opposition, a lower TLR2 expression was induced by virulent EVs. Additionally, virulent EVs induced lower expression of CD80, CD86 and TNF-α, but promoted a higher expression of IL-6 and IL-10, suggesting that EVs isolated from virulent P. brasiliensis-yeast promote a milder DCs and macrophage maturation. Herein, we showed that EVs from virulent fungi stimulated a higher frequency of Th1/Tc1, Th17, and Treg cells, which gives new insights into fungal extracellular vesicles. Taken together, our results suggest that P. brasiliensis utilizes its EVs as virulence bags that manipulate the immune system in its favour, creating a milder immune response and helping with fungal evasion from the immune system.

Case Report: Disseminated Paracoccidioidomycosis and Strongyloides Hyperinfection in a Patient with Human T-Lymphotropic Virus Type 1/2 Infection.

Co-occurrence of paracoccidioidomycosis and strongyloidiasis in immunosuppressed patients, particularly those infected with human T-lymphotropic virus type 1/2, is infrequent. We describe the case of a Peruvian farmer from the central jungle with human T-lymphotropic virus type 1/2 infection, with 2 months of illness characterized by respiratory and gastrointestinal symptoms associated with fever, weight loss, and enlarged lymph nodes. Strongyloides stercoralis and Paracoccidioides brasiliensis were isolated in sputum and bronchoalveolar lavage samples, respectively. The clinical evolution was favorable after the patient received ivermectin and amphotericin B. We hypothesize that autoinfestation by S. stercoralis in human T-lymphotropic virus type 1/2-infected patients may contribute to the disseminated presentation of Paracoccidioides spp. Understanding epidemiological context is crucial for suspecting opportunistic regional infections, particularly those that may coexist in immunosuppressed patients.

Recombinant 60-kDa heat shock protein from Paracoccidioides brasiliensis induces the death of mouse lymphocytes in a mechanism dependent on Toll-like receptor 4 and tumor necrosis factor.

Paracoccidioides fungi are thermodimorphic microorganisms that cause paracoccidioidomycosis (PCM), an autochthonous disease from Latin America, with most cases in Brazil. Humans become infected by inhaling conidia or mycelial fragments that transform into yeast at body temperature. These fungi cause chronic-granulomatous inflammation, which may promote fibrosis and parenchyma destruction in the lungs. In response to stress imposed by the host, fungi Paracoccidioides spp. increase the expression of heat shock proteins (HSP), which protect them by sustaining cellular proteostasis. Our group has studied the role of HSP60 in PCM, and previous data show that the recombinant HSP60 (rHSP60) has a deleterious effect when used in a single dose as therapy for experimental PCM. Here, we investigated the mechanism by which rHSP60 could worsen the disease. We found that rHSP60 caused the viability loss of splenic or lymph node cells from both immunized and non-immunized mice, including in splenic T lymphocytes under polyclonal stimulation with concanavalin A, probably by undergoing apoptosis. Among analyzed splenic cells, lymphocytes were indeed the main cells to die. When we investigated the death mechanisms, remarkably, we found that there was no viability loss in rHSP60-stimulated splenic cells from mice deficient in Toll-like receptor 4, TRIF adapter protein, and TNF receptor 1(TNFR1), as well as rHSP60-stimulated WT cells incubated with anti-TNF antibody. Besides, caspase-8 inhibitor IETD-CHO blocked the rHSP60 effect on splenic cells, suggesting that rHSP60 induces the extrinsic apoptosis pathway dependent on signaling via TLR4/TRIF and TNFR1.

Unveiling the functional significance of the 14.3.3 protein: A key player in Paracoccidioides brasiliensis biofilm formation.

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by Paracoccidioides spp. The interaction mediated by the presence of adhesins on the fungal surface and receptors in the extracellular matrix of the host, as well as the biofilm formation, is essential in its pathogenesis. Adhesins such as gp43, enolase, GAPDH (glyceraldehyde-3-phosphate dehydrogenase), and 14-3-3 have been demonstrated in the Paracoccidioides brasiliensis (Pb18) strain and recognized as necessary in the fungus-host interaction. The Pb 18 strain silenced to 14-3-3 showed changes in morphology, virulence, and adhesion capacity. The study aimed to evaluate the role of adhesin 14-3-3 in P. brasiliensis biofilm formation and the differential expression of genes related to adhesins, comparing planktonic and biofilm forms. The presence of biofilm was also verified in sutures in vitro and in vivo. The silenced strain (Pb14-3-3 aRNA) was compared with the wild type Pb18, determining the differential metabolic activity between the strains by the XTT reduction assay; the biomass by violet crystal and the polysaccharides by safranin, even as morphological differences by microscopic techniques. Differential gene expression for adhesins was also analyzed, comparing the relative expression of these in planktonic and biofilm forms at different times. The results suggested that the silencing of 14-3-3 protein altered the ability to form biofilm and its metabolism. The quantity of biomass was similar in both strains; however, the formation of exopolymeric substances and polysaccharide material was lower in the silenced strain. Our results showed increased expression of enolase, GAPDH, and 14-3-3 genes in the first periods of biofilm formation in the Pb18 strain. In contrast, the silenced strain showed a lower expression of these genes, indicating that gene silencing can influence the expression of other genes and be involved in the biofilm formation of P. brasiliensis. In vitro and in vivo assays using sutures confirmed this yeast's ability to form biofilm and may be implicated in the pathogenesis of paracoccidioidomycosis.

Molecular detection of Paracoccidioides spp. in environmental samples from the Southwestern Amazon.

Paracoccidioidomycosis is an infection with the potential for environmental dissemination, especially in regions of hot and humid climate, where human cases have been recorded in the Southwestern Amazon of Brazil, specifically in the state of Acre. Despite studies providing information about the presence of these fungi in soil and animal samples, such as armadillos, further investigations are still needed to determine the epidemiological distribution of the genus Paracoccidioides. The aim of this study was to detect the occurrence of Paracoccidioides fungi in the Southwestern Amazon. To achieve this, 60 soil samples were collected from armadillo burrows on rural properties in the in the municipalities of Acrelândia, Bujari, Plácido de Castro, Rio Branco, Sena Madureira, and Senador Guiomard, located in the state of Acre, Brazil. Fungal DNA was extracted from these samples using the DNEASY® PowerSoil kit-Quiagen, followed by Nested PCR technique with ITS4 and ITS5 as external primers, and PBITS-E and PBITS-R as internal primers. DNA amplification products of about 380 bp compatible with Paracoccidioides spp. were detected in six samples (10%), being sequenced and identified as P. brasiliensis. These findings indicate that the soils of the Acre state could be considered a potential source for Paracoccidioides spp., suggesting that local infections are likely.

Structure of glyceraldehyde-3-phosphate dehydrogenase from Paracoccidioides lutzii in complex with an aldonic sugar acid.

The pathogen Paracoccidioides lutzii (Pb01) is found in South America countries Colombia, Ecuador, Venezuela and Brazil, especially in the central, west, and north regions of the latter. It belongs to the Ajellomycetaceae family, Onygenales order, and is typically thermodimorphic, presenting yeast cells when it grows in animal tissues, but mycelia when in the environment, where it produces the infectious propagule. This fungus is one of the etiologic agents of Paracoccidioidomycosis (PCM), the most important endemic fungal infection in Latin America. Investigations on its genome have contributed to a better understanding about its metabolism and revealed the complexity of several metabolic glycolytic pathways. Glyceraldehyde-3-Phosphate Dehydrogenase from Paracoccidioides lutzii (PlGAPDH) is considered a moonlighting protein and participates in several biological processes of this pathogen. The enzyme was expressed and purified, as seen in SDS-PAGE gel, crystallized and had its three dimensional structure (3D) determined in complex with NAD+, a sulphate ion and d-galactonic acid, therefore, a type of 'GAA site'. It is the first GAPDH structure to show this chemical type in this site and how this protein can bind an acid derived from oxidation of a linear hexose.

Proteomic analysis reveals changes in the proteome of human THP-1 macrophages infected with Paracoccidioides brasiliensis.

Paracoccidioides spp. is the etiologic agent of Paracoccidioidomycosis (PCM), a systemic disease with wide distribution in Latin America. Macrophages are very important cells during the response to infection by P. brasiliensis. In this study, we performed a proteomic analysis to evaluate the consequences of P. brasiliensis yeast cells on the human THP-1 macrophage proteome. We have identified 443 and 2247 upregulated or downregulated proteins, respectively, in macrophages co-cultured with yeast cells of P. brasiliensis in comparison to control macrophages unexposed to the fungus. Proteomic analysis revealed that interaction with P. brasiliensis caused metabolic changes in macrophages that drastically affected energy production pathways. In addition, these macrophages presented regulated many factors related to epigenetic modifications and gene transcription as well as a decrease of many proteins associated to the immune system activity. This is the first human macrophage proteome derived from interactions with P. brasiliensis, which contributes to elucidating the changes that occur during the host response to this fungus. Furthermore, it highlights proteins that may be targets for the development of new therapeutic approaches to PCM.

Can COVID-19 impact the natural history of paracoccidioidomycosis? Insights from an atypical chronic form of the mycosis.

Paracoccidioidomycosis (PCM) is a systemic fungal infection caused by Paracoccidioides spp. It can occur as an acute/subacute form (A/SAF), a chronic form (CF) and rarely as a mixed form combining the features of the two aforementioned forms in an immunocompromised patient. Here, we report a 56-year-old male patient with CF-PCM who presented with atypical manifestations, including the development of an initial esophageal ulcer, followed by central nervous system (CNS) lesions and cervical and abdominal lymphatic involvement concomitant with severe SARS-CoV-2 infection. He was HIV-negative and had no other signs of previous immunodeficiency. Biopsy of the ulcer confirmed its mycotic etiology. He was hospitalized for treatment of COVID-19 and required supplemental oxygen in the intensive unit. The patient recovered without the need for invasive ventilatory support. Investigation of the extent of disease during hospitalization revealed severe lymphatic involvement typical of A/SAF, although the patient`s long history of high-risk exposure to PCM, and lung involvement typical of the CF. Esophageal involvement is rare in non-immunosuppressed PCM patients. CNS involvement is also rare. We suggest that the immunological imbalance caused by the severe COVID-19 infection may have contributed to the patient developing atypical severe CF, which resembles the PCM mixed form of immunosuppressed patients. Severe COVID-19 infection is known to impair the cell-mediated immune response, including the antiviral response, through T-lymphopenia, decreased NK cell counts and T-cell exhaustion. We hypothesize that these alterations would also impair antifungal defenses. Our case highlights the potential influence of COVID-19 on the course of PCM. Fortunately, the patient was timely treated for both diseases, evolving favorably.

Dectin-2 is critical for phagocyte function and resistance to Paracoccidioides brasiliensis in mice.

Germline-encoded pattern recognition receptors, particularly C-type lectin receptors (CLRs), are essential for phagocytes to sense invading fungal cells. Among CLRs, Dectin-2 (encoded by Clec4n) plays a critical role in the antifungal immune response as it recognizes high-mannose polysaccharides on the fungal cell wall, triggering phagocyte functional activities and ultimately determining adaptive responses. Here, we assessed the role of Dectin-2 on the course of primary Paracoccidioides brasiliensis systemic infection in mice with Dectin-2-targeted deletion. Paracoccidioides brasiliensis constitutes the principal etiologic agent of paracoccidioidomycosis, the most prominent invasive mycosis in Latin American countries. The deficiency of Dectin-2 resulted in shortened survival rates, high lung fungal burden, and increased lung pathology in mice infected with P. brasiliensis. Consistently, dendritic cells (DCs) from mice lacking Dectin-2 infected ex vivo with P. brasiliensis showed impaired secretion of several proinflammatory and regulatory cytokines, including TNF-α, IL-1ß, IL-6, and IL-10. Additionally, when cocultured with splenic lymphocytes, DCs were less efficient in promoting a type 1 cytokine pattern secretion (i.e., IFN-γ). In macrophages, Dectin-2-mediated signaling was required to ensure phagocytosis and fungicidal activity associated with nitric oxide production. Overall, Dectin-2-mediated signaling is critical to promote host protection against P. brasiliensis infection, and its exploitation might lead to the development of new vaccines and immunotherapeutic approaches.

We report a critical role of the innate immune receptor Dectin-2 during Paracoccidioides brasiliensis infection. Fungal sensing by Dectin-2 improved the survival of mice and lowered fungal burden. Further, Dectin-2 was required for cytokine production, phagocytosis, and fungal killing by phagocytes.

Human Lobomycosis Caused by Paracoccidioides (Lacazia) loboi, Panama, 2022.

We report a patient from Panama who had lobomycosis caused by Paracoccidioides (Lacazia) loboi. We used combined clinical-epidemiologic and phylogenetic data, including a new gene sequence dataset on this fungus in Panama, for analysis. Findings contribute useful insights to limited knowledge of this fungal infection in the Mesoamerican Biologic Corridor.

Transcriptional profiling of a fungal granuloma reveals a low metabolic activity of Paracoccidioides brasiliensis yeasts and an actively regulated host immune response.

Granulomas are important immunological structures in the host defense against the fungus Paracoccidioides brasiliensis, the main etiologic agent of Paracoccidioidomycosis (PCM), a granulomatous systemic mycosis endemic in Latin America. We have performed transcriptional and proteomic studies of yeasts present in the pulmonary granulomas of PCM aiming to identify relevant genes and proteins that act under stressing conditions. C57BL/6 mice were infected with 1x106 yeasts and after 8- and 12-weeks of infection, granulomatous lesions were obtained for extraction of fungal and murine RNAs and fungal proteins. Dual transcriptional profiling was done comparing lung cells and P. brasiliensis yeasts from granulomas with uninfected lung cells and the original yeast suspension used in the infection, respectively. Mouse transcripts indicated a lung malfunction, with low expression of genes related to muscle contraction and organization. In addition, an increased expression of transcripts related to the activity of neutrophils, eosinophils, macrophages, lymphocytes as well as an elevated expression of IL-1ß, TNF-α, IFN-γ, IL-17 transcripts were observed. The increased expression of transcripts for CTLA-4, PD-1 and arginase-1, provided evidence of immune regulatory mechanisms within the granulomatous lesions. Also, our results indicate iron as a key element for the granuloma to function, where a high number of transcripts related to fungal siderophores for iron uptake was observed, a mechanism of fungal virulence not previously described in granulomas. Furthermore, transcriptomics and proteomics analyzes indicated a low fungal activity within the granuloma, as demonstrated by the decreased expression of genes and proteins related to energy metabolism and cell cycle.

Cheminformatics-driven discovery of hit compounds against Paracoccidioides spp.

Aims: The development of safe and effective therapies for treating paracoccidioidomycosis using computational strategies were employed to discover anti-Paracoccidioides compounds. Materials & methods: We 1) collected, curated and integrated the largest library of compounds tested against Paracoccidioides spp.; 2) employed a similarity search to virtually screen the ChemBridge database and select nine compounds for experimental evaluation; 3) performed an experimental evaluation to determine the minimum inhibitory concentration and minimum fungicidal concentration as well as cytotoxicity; and 4) employed computational tools to identify potential targets for the most active compounds. Seven compounds presented activity against Paracoccidioides spp. Conclusion: These compounds are new hits with a predicted mechanisms of action, making them potentially attractive to develop new compounds.

Fast and cost-effective protocol to produce Paracoccidioides spp. antigens / Protocolo rápido y económico para la producción de antígenos de Paracoccidioides spp

INTRODUCTION: The existing methods for Paracoccidioides spp. antigen production are problematic in terms of standardization, specificity, stability, repeatability, and reproducibility. OBJECTIVE: To optimize the methodology for Paracoccidioides spp. antigen production and evaluate its applicability in paracoccidioidomycosis immunodiagnosis. MATERIALS AND METHODS: The antigens were obtained from Paracoccidioides lutzii isolates (01, 66, and 8334), Paracoccidioides brasiliensis sensu stricto (113), and Paracoccidioides restripiensis (B-339). These fungi were grown at 36 °C ± 1 °C, on modified Fava-Netto agar, according to Freitas et al. (2018). Paracoccidioides lutzii antigens were obtained after , 10, and 20 days of culture, whereas P. brasiliensis and P. restripiensis antigens were obtained after 10 days. Antigens were evaluated in natura, 10 and 20 times concentrated. Antigenic capacity was evaluated using a double immunodiffusion assay against serum samples from patients with paracoccidioidomycosis, histoplasmosis, and aspergillosis, and random blood donors. RESULTS: Cross-reactivity between Paracoccidioides spp. antigens was observed when P. brasiliensis, P. restrepiensis antigens, and P. lutzii antigens were evaluated with the polyclonal antibodies against P. lutzii and P. brasiliensis, respectively. No cross-reactivity was obtained for polyclonal antibodies against Histoplasma capsulatum, Aspergillus fumigatus, and random blood donors. The proposed protocol allowed stable, repeatable, and reproducible genus-specific antigen production at a low cost and in a short cultivation time. CONCLUSION: The proposed protocol allowed us to obtain genus-specific antigens that can be developed and reproduced in all laboratories in Brazil and South America, where paracoccidioidomycosis is a neglected disease, contributing to an early diagnosis, especially in endemic regions, regardless of the species.

Introducción: Los métodos existentes para la producción de los antígenos de Paracoccidioides spp. son problemáticos en su estandarización, especificidad, estabilidad, repetibilidad y reproducibilidad. Objetivo: Optimizar la metodología para la producción de antígenos de Paracoccidioides spp. y evaluar su aplicabilidad en el inmunodiagnóstico de la paracoccidioidomicosis. Materiales y métodos: Los antígenos se obtuvieron de aislamientos de P. lutzii (01, 66 y 8334), P. brasiliensis sensu stricto (113) y P. restripiensis (B-339). Estos hongos se cultivaron a 36 °C ± 1 °C en agar Fava-Netto modificado, según Freitas et al. (2018). Los antígenos de P. lutzii se obtuvieron a los 5, 10 y 20 días de cultivo y los antígenos de P. brasiliensis y P. restripiensis se obtuvieron a los 10 días. Los antígenos se evaluaron in natura, concentrados 10 y 20 veces. La capacidad antigénica se evaluó mediante un ensayo de inmunodifusión doble con muestras de suero de pacientes con paracoccidioidomicosis, histoplasmosis, aspergilosis y donantes de sangre aleatorios. Resultados: Se observó reacción cruzada con Paracoccidioides spp. cuando se evaluaron los antígenos de P. brasiliensis, P. restrepiensis y P. lutzii frente a los anticuerpos policlonales contra P. lutzii y P. brasiliensis, respectivamente. No hubo reactividad cruzada con los anticuerpos policlonales contra Histoplasma capsulatum y Aspergillus fumigatus, ni contra los donantes de sangre aleatorios. El protocolo propuesto permitió la producción estable, repetible y reproducible de antígenos dirigidos de un género específico (Paracoccidiodes) en un tiempo corto de cultivo y a un menor costo. Conclusión: El protocolo propuesto permitió obtener antígenos específicos de un género, que pueden ser desarrollados y reproducidos en todos los laboratorios de Brasil y Surámerica donde la paracoccidioidomicosis es una enfermedad endémica y desatendida. Estos antígenos pueden contribuir al diagnóstico precoz de la infección, independientemente de la especie.

Hiperplasia pseudoepiteliomatosa: carcinoma escamocelular versus paracoccidioidomicosis oral, un caso con mirada dermatológica / Pseudoepitheliomatous hyperplasia: Squamous cell carcinoma versus oral paracoccidioidomycosis, a case from a dermatological perspective

La paracoccidioidomicosis es una micosis sistémica endémica en Latinoamérica. La presentación más frecuente compromete crónicamente los pulmones, la piel y las mucosas. Al inicio, este paciente presentó, por varios años, una lesión única en la mucosa oral que, en ausencia de otros síntomas, se relacionó con una neoplasia maligna, específicamente con un carcinoma escamocelular. La diferenciación entre los dos diagnósticos se hace mediante un examen directo, un estudio histopatológico y cultivos iniciales y subsecuentes. Sin embargo, tales estudios no fueron concluyentes. Después de varias consultas y pruebas, con los resultados del examen directo, la inmunodifusión y la PCR en tiempo real se confirmó el diagnóstico de paracoccidioidomicosis crónica multifocal. Este caso alerta sobre la ausencia de sospecha clínica de micosis endémicas, dada la presencia de lesiones mucocutaneas que pueden ser producidas por hongos como Paracoccidioides spp, y la importancia de considerarlas entre los diagnósticos diferenciales.

Paracoccidioidomycosis is a systemic mycosis endemic in Latin America. The most frequent form involves a chronic compromise of the lungs, skin, and mucosa. The patient started with a single oral lesion that lasted for several years. The absence of other symptoms pointed out a possible malignant neoplasm, specifically a squamous cell carcinoma. Differentiation between both diagnoses-fungal infection and carcinoma-depends on the results of the direct examination, the histopathological study, and the initial and subsequent cultures. However, in this case, those findings were not conclusive. The coexistence of both diagnoses is frequent and increases the diagnostic challenge. After several consultations and tests, direct examination, immunodiffusion and real-time PCR findings the multifocal chronic paracoccidioidomycosis diagnosis was confirmed. This case warns about a systematical absence of clinical suspicion of endemic mycoses before the appereance of mucocutaneous lesions, which can be produced by fungi like Paracoccidioides spp, and the importance of considering those mycoses among the differential diagnoses.

Diagnóstico micológico de paracoccidioidomicosis en un hospital de área no endémica: metodología clásica y molecular / Mycological diagnosis of paracoccidioidomycosis in a hospital from a nonendemic area: classical and molecular methods

Introducción. La paracoccidioidomicosis es una micosis sistémica y endémica en Latinoamérica. El cambio climático y el movimiento migratorio del huésped enfatizan la necesidad de optimizar el diagnóstico de esta infección. Objetivo. Evaluar la implementación de la detección de ADN de Paracoccidioides spp. al diagnóstico micológico de pacientes con sospecha de paracoccidioidomicosis. Materiales y métodos. Estudio retrospectivo con datos de laboratorio de pacientes con sospecha de paracoccidioidomicosis en un hospital de área no endémica. Resultados. Se analizaron los resultados de las muestras de 19 pacientes con sospecha clínica de paracoccidioidomicosis. El 90 % de los pacientes había nacido o visitado un área endémica de esta micosis en Latinoamérica. En 14 pacientes varones adultos se confirmó paracoccidioidomicosis por diagnóstico convencional. El examen directo fue positivo en 12 pacientes con enfermedad comprobada y en 4 de ellos se obtuvo crecimiento del hongo. Se detectaron anticuerpos contra Paracoccidioides spp. en ocho pacientes con la enfermedad. Se realizó PCR anidada con muestras de 14 pacientes para detectar ADN de Paracoccidioides spp. En 9 de los 10 pacientes con diagnóstico convencional de paracoccidioidomicosis se obtuvo una prueba de PCR positiva. Conclusiones. La implementación de técnicas moleculares para detectar ADN de Paracoccidioides spp. complementa el diagnóstico convencional de paracoccidioidomicosis y permite instaurar el tratamiento antifúngico, sobre todo en los casos clínicos donde no se observa la presencia del hongo en las muestras clínicas. La migración actual de poblaciones humanas dificulta el diagnóstico de paracoccidioidiomicosis y otras infecciones endémicas, por lo que se requiere optimizar el diagnostico micológico en los laboratorios clínicos para tratar pacientes con este tipo micosis desatendida.

Introduction. Paracoccidioidomycosis is a systemic mycosis endemic in Latin America. Climate change and host migration emphasize the need to optimize this infection diagnosis. Objective. To evaluate the implementation of Paracoccidioides spp. DNA detection in the mycological diagnosis of patients with suspected paracoccidioidomycosis. Materials and methods. It is a retrospective study with laboratory data from patients with clinical suspicion of paracoccidioidomycosis, who consulted a university hospital from a non-endemic area. Results. We analyzed the laboratory results of samples from 19 patients with suspected paracoccidioidomycosis. Seventeen out of 19 patients were born in or had visited an endemic area in Latin America. Fourteen adult male patients were confirmed to have paracoccidioidomycosis by conventional diagnosis: the direct examination was positive in 12 samples while fungal growth was found only in 4. Anti-Paracoccidioides spp. antibodies were detected in 10 patients, 8 of them with proven paracoccidioidomycosis. Nested PCR for Paracoccidioides spp. detection was performed on clinical samples from 14 patients, and positive results were obtained for 9 out of 10 patients with the conventional diagnosis of paracoccidioidomycosis. Conclusions. The incorporation of molecular techniques to detect Paracoccidioides spp. DNA complements the conventional diagnosis of paracoccidioidomycosis. This tool allows the prescription of antifungal treatment in those cases where the fungus is not observed in the clinical samples. Current human migrations difficult the mycological diagnosis of paracoccidioidomycosis and other fungal infections. For this reason, it is necessary to improve mycological diagnosis in clinical laboratories to adequately treat patients with this neglected mycosis.

Fast and cost-effective protocol to produce Paracoccidioides spp. antigens / Protocolo rápido y económico para la producción de antígenos de Paracoccidioides spp

Introduction. The existing methods for Paracoccidioides spp. antigen production are problematic in terms of standardization, specificity, stability, repeatability, and reproducibility. Objective. To optimize the methodology for Paracoccidioides spp. antigen production and evaluate its applicability in paracoccidioidomycosis immunodiagnosis. Materials and methods. The antigens were obtained from Paracoccidioides lutzii isolates (01, 66, and 8334), Paracoccidioides brasiliensis sensu stricto (113), and Paracoccidioides restripiensis (B-339). These fungi were grown at 36 °C ± 1 °C, on modified Fava-Netto agar, according to Freitas et al. (2018). Paracoccidioides lutzii antigens were obtained after 5, 10, and 20 days of culture, whereas P. brasiliensis and P. restripiensis antigens were obtained after 10 days. Antigens were evaluated in natura, 10 and 20 times concentrated. Antigenic capacity was evaluated using a double immunodiffusion assay against serum samples from patients with paracoccidioidomycosis, histoplasmosis, and aspergillosis, and random blood donors. Results. Cross-reactivity between Paracoccidioides spp. antigens was observed when P. brasiliensis, P. restrepiensis antigens, and P. lutzii antigens were evaluated with the polyclonal antibodies against P. lutzii and P. brasiliensis, respectively. No cross-reactivity was obtained for polyclonal antibodies against Histoplasma capsulatum, Aspergillus fumigatus, and random blood donors. The proposed protocol allowed stable, repeatable, and reproducible genus-specific antigen production at a low cost and in a short cultivation time. Conclusion. The proposed protocol allowed us to obtain genus-specific antigens that can be developed and reproduced in all laboratories in Brazil and South America, where paracoccidioidomycosis is a neglected disease, contributing to an early diagnosis, especially in endemic regions, regardless of the species.

Introducción. Los métodos existentes para la producción de los antígenos de Paracoccidioides spp. son problemáticos en su estandarización, especificidad, estabilidad, repetibilidad y reproducibilidad. Objetivo. Optimizar la metodología para la producción de antígenos de Paracoccidioides spp. y evaluar su aplicabilidad en el inmunodiagnóstico de la paracoccidioidomicosis. Materiales y métodos. Los antígenos se obtuvieron de aislamientos de P. lutzii (01, 66 y 8334), P. brasiliensis sensu stricto (113) y P. restripiensis (B-339). Estos hongos se cultivaron a 36 °C ± 1 °C en agar Fava-Netto modificado, según Freitas et al. (2018). Los antígenos de P. lutzii se obtuvieron a los 5, 10 y 20 días de cultivo y los antígenos de P. brasiliensis y P. restripiensis se obtuvieron a los 10 días. Los antígenos se evaluaron in natura, concentrados 10 y 20 veces. La capacidad antigénica se evaluó mediante un ensayo de inmunodifusión doble con muestras de suero de pacientes con paracoccidioidomicosis, histoplasmosis, aspergilosis y donantes de sangre aleatorios. Resultados. Se observó reacción cruzada con Paracoccidioides spp. cuando se evaluaron los antígenos de P. brasiliensis, P. restrepiensis y P. lutzii frente a los anticuerpos policlonales contra P. lutzii y P. brasiliensis, respectivamente. No hubo reactividad cruzada con los anticuerpos policlonales contra Histoplasma capsulatum y Aspergillus fumigatus, ni contra los donantes de sangre aleatorios. El protocolo propuesto permitió la producción estable, repetible y reproducible de antígenos dirigidos de un género específico (Paracoccidiodes) en un tiempo corto de cultivo y a un menor costo. Conclusión. El protocolo propuesto permitió obtener antígenos específicos de un género, que pueden ser desarrollados y reproducidos en todos los laboratorios de Antígenos de Paracoccidioides spp.: protocolo rápido Brasil y Surámerica donde la paracoccidioidomicosis es una enfermedad endémica y desatendida. Estos antígenos pueden contribuir al diagnóstico precoz de la infección, independientemente de la especie.

Proteomic identification of metabolic changes in Paracoccidioides brasiliensis induced by a nitroheteroarylchalcone.

Aim: To access the metabolic changes caused by a chalcone derivative (LabMol-75) through a proteomic approach. Methods: Proteomic analysis was performed after 9 h of Paracoccidioides brasiliensis yeast (Pb18) cell incubation with the LabMol-75 at MIC. The proteomic findings were validated through in vitro and in silico assays. Results: Exposure to the compound led to the downregulation of proteins associated with glycolysis and gluconeogenesis, ß-oxidation, the citrate cycle and the electron transport chain. Conclusion: LabMol-75 caused an energetic imbalance in the fungus metabolism and deep oxidative stress. Additionally, the in silico molecular docking approach pointed to this molecule as a putative competitive inhibitor of DHPS.

Peritonitis caused by paracoccidioides spp. in a patient on continuous ambulatory peritoneal dialysis - A case report.

Paracoccidioidomycosis is a systemic mycosis found mainly in South America and is the most prevalent endemic and systemic mycosis in Brazil. The purpose of this paper was to report the case of a male patient who developed peritonitis caused by Paracoccidioides spp. Forty-eight-year-old, male patient, with type I Diabetes mellitus and chronic kidney disease who was undergoing a Continuous Ambulatory Peritoneal Dialysis (CAPD) program. After eighteen months of peritoneal dialysis, the patient developed turbidity of the peritoneal fluid and was diagnosed with peritonitis. Direct mycological examination of the peritoneal fluid revealed yeasts with morphology suggestive of Paracoccidioides spp. The patient was treated with sulfamethoxazole-trimethoprim (1,600 mg/320 mg dose/day) for 61 days, but he died because a bacterial septic shock. The diagnosis of opportunistic PCM peritonitis was later confirmed by autopsy and Paracoccidioides spp. isolation. This is the first reported case of a patient on CAPD who experienced complications due peritonitis caused by opportunistic PCM.