Unusual Differences in the Pulmonary Histopathology of Mice after Intranasal Infection with Mycelial Propagules of Strains Classified as LAm A2 and NAm 2 Phylogenetic Species.

The ascomycete is the causative agent of systemic respiratory mycosis histoplasmosis, which sometimes develops acute disseminated or chronic clinical forms, with the latter usually associated with granuloma formation. The present report shows differential histopathological changes in the pulmonary inflammatory response of mice infected intranasally with the mycelial morphotype of strains with distinct genotypes, EH-46 and G-217B, classified as LAm A2 and NAm 2 phylogenetic species, respectively. Infected male BALB/c mice were sacrificed at different postinfection times, and their serial lung sections were stained with periodic acid-Schiff and analyzed via microscopy.

Central Nervous System Histoplasmosis: An Updated Insight.

Histoplasmosis is one of the systemic mycoses that can involve the Central Nervous System (CNS), and it is caused by the dimorphic ascomycete species of the complex. Once in the CNS, this pathogen causes life-threatening injuries that are associated with clinical manifestations of meningitis, focal lesions (abscesses, histoplasmomas), and spinal cord injuries. The present review provides updated data and highlights a particular vision regarding this mycosis and its causative agent, as well as its epidemiology, clinical forms, pathogenesis, diagnosis, and therapy, focusing on the CNS.

The Notch1/CD22 signaling axis disrupts Treg function in SARS-CoV-2-associated multisystem inflammatory syndrome in children.

Multisystem inflammatory syndrome in children (MIS-C) evolves in some pediatric patients following acute infection with SARS-CoV-2 by hitherto unknown mechanisms. Whereas acute-COVID-19 severity and outcomes were previously correlated with Notch4 expression on Tregs, here, we show that Tregs in MIS-C were destabilized through a Notch1-dependent mechanism. Genetic analysis revealed that patients with MIS-C had enrichment of rare deleterious variants affecting inflammation and autoimmunity pathways, including dominant-negative mutations in the Notch1 regulators NUMB and NUMBL leading to Notch1 upregulation.

Considerations about the Geographic Distribution of Species.

Histoplasmosis is a mycotic infection principally affecting pulmonary tissue; sometimes, histoplasmosis can progress into a systemic disease. This infection involves immunocompetent and immunosuppressed human and other mammalian hosts, depending on particular circumstances. Histoplasmosis infection has been documented worldwide.

Detection of Cytokines and Collectins in Bronchoalveolar Fluid Samples of Patients Infected with and .

Histoplasmosis and pneumocystosis co-infections have been reported mainly in immunocompromised humans and in wild animals. The immunological response to each fungal infection has been described primarily using animal models; however, the host response to concomitant infection is unknown. The present work aimed to evaluate the pulmonary immunological response of patients with pneumonia caused either by , , or their co-infection.

Isolated from Bats Captured in Mexico Form a Sister Group to North American Class 2 Clade.

is a dimorphic fungus associated with respiratory and systemic infections in mammalian hosts that have inhaled infective mycelial propagules. A phylogenetic reconstruction of this pathogen, using partial sequences of , , , and protein-coding genes, proposed that has at least 11 phylogenetic species, highlighting a clade (BAC1) comprising three isolates from infected bats captured in Mexico. Here, relationships for each individual locus and the concatenated coding regions of these genes were inferred using parsimony, maximum likelihood, and Bayesian inference methods.

Heat Shock Protein 60, Insights to Its Importance in : From Biofilm Formation to Host-Interaction.

Heat shock proteins (Hsps) are among the most widely distributed and evolutionary conserved proteins, acting as essential regulators of diverse constitutive metabolic processes. The Hsp60 of the dimorphic fungal is the major surface adhesin to mammalian macrophages and studies of antibody-mediated protection against  have provided insight into the complexity involving Hsp60. However, nothing is known about the role of Hsp60 regarding biofilms, a mechanism of virulence exhibited by .

Differential miRNA Expression in Human Macrophage-Like Cells Infected with Yeasts Cultured in Planktonic and Biofilm Forms.

affects healthy and immunocompromised individuals, sometimes causing a severe disease. This fungus has two morphotypes, the mycelial (infective) and the yeast (parasitic) phases. MicroRNAs (miRNAs) are small RNAs involved in the regulation of several cellular processes, and their differential expression has been associated with many disease states.

Biofilm Formation by in Different Culture Media and Oxygen Atmospheres.

is a dimorphic fungus that causes an important systemic mycosis called histoplasmosis. It is an infectious disease with high prevalence and morbidity that affects the general population. Recently, the ability of these fungi to form biofilms, a phenotype that can induce resistance and enhance virulence, has been described.

Thermotolerance of Histoplasma capsulatum at 40 °C predominates among clinical isolates from different Latin American regions.

The yeast phase of 22 Histoplasma capsulatum clinical isolates from Mexico, Argentina, Colombia, and Guatemala and three reference strains, one from Panama and two from the United States of America (USA), were screened for thermosensitivity characteristics using different analyses. Growth curves at 0, 3, 6, 12, 24, and 30 h of incubation at 37 and 40 °C, the growth inhibition percentage at 40 °C, and the doubling time at 37 and 40 °C were determined for all yeasts studied. Most of the isolates examined exhibited thermotolerant phenotypes at 40 °C, whereas a thermosensitive phenotype at 40 °C was only detected in the Downs reference strain from the USA.

Novel clinical and dual infection by Histoplasma capsulatum genotypes in HIV patients from Northeastern, Brazil.

Histoplasmosis is a worldwide-distributed deep mycosis that affects healthy and immunocompromised hosts. Severe and disseminated disease is especially common in HIV-infected patients. At least 11 phylogenetic species are recognized and the majority of diversity is found in Latin America.

Dimorphism and Dissemination of in the Upper Respiratory Tract after Intranasal Infection of Bats and Mice with Mycelial Propagules.

This article describes, for the first time, the role of the nasal mucosa (NM) as the initial site for the mycelial-to-yeast transition. The results highlight that yeasts may arrive to the cervical lymph nodes (CLN) via phagocytes. Bats and mice were intranasally infected with mycelial propagules and they were killed 10, 20, and 40 minutes and 1, 2, and 3 hours after infection.

Histoplasma capsulatum and Pneumocystis jirovecii coinfection in hospitalized HIV and non-HIV patients from a tertiary care hospital in Mexico.

Background: Histoplasma capsulatum and Pneumocystis jirovecii are respiratory fungal pathogens that principally cause pulmonary disease. Coinfection with both pathogens is scarcely reported. This study detected this coinfection using specific molecular methods for each fungus in the bronchoalveolar lavage (BAL) of patients from a tertiary care hospital.

Mixed infection by Histoplasma capsulatum isolates with different mating types in Brazilian AIDS-patients.

Mixed infection by Histoplasma capsulatum isolates with different mating types, in AIDS-patients are described in this study. Morphological, mating type-specific PCR assay and multilocus sequencing type analysis of H. capsulatum isolates recovered from two Brazilian AIDS-patients were performed.

Multiplex polymerase chain reaction as an improved method for screening Histoplasma capsulatum mating types.

Histoplasmosis is a systemic mycosis infection caused by Histoplasma capsulatum, a heterothallic ascomycete. The sexual reproduction of this fungus is regulated by the mating type (MAT1) locus that contains MAT1-1 and MAT1-2 idiomorphs, which were identified by uniplex polymerase chain reaction (PCR). This study aimed to optimise single-step multiplex PCR for the accurate detection of the distinct mating types of H.

Usefulness of molecular markers in the diagnosis of occupational and recreational histoplasmosis outbreaks.

Histoplasmosis is considered the most important systemic mycosis in Mexico, and its diagnosis requires fast and reliable methodologies. The present study evaluated the usefulness of PCR using Hcp100 and 1281-1283 molecular markers in detecting Histoplasma capsulatum in occupational and recreational outbreaks. Seven clinical serum samples of infected individuals from three different histoplasmosis outbreaks were processed by enzyme-linked immunosorbent assay (ELISA) to titre anti-H.

Surfactant proteins, SP-A and SP-D, in respiratory fungal infections: their role in the inflammatory response.

Pulmonary surfactant is a complex fluid that comprises phospholipids and four proteins (SP-A, SP-B, SP-C, and SP-D) with different biological functions. SP-B, SP-C, and SP-D are essential for the lungs' surface tension function and for the organization, stability and metabolism of lung parenchyma. SP-A and SP-D, which are also known as pulmonary collectins, have an important function in the host's lung immune response; they act as opsonins for different pathogens via a C-terminal carbohydrate recognition domain and enhance the attachment to phagocytic cells or show their own microbicidal activity by increasing the cellular membrane permeability.

An Intracellular Arrangement of Histoplasma capsulatum Yeast-Aggregates Generates Nuclear Damage to the Cultured Murine Alveolar Macrophages.

Histoplasma capsulatum is responsible for a human systemic mycosis that primarily affects lung tissue. Macrophages are the major effector cells in humans that respond to the fungus, and the development of respiratory disease depends on the ability of Histoplasma yeast cells to survive and replicate within alveolar macrophages. Therefore, the interaction between macrophages and H.

Profile of cytokines in the lungs of BALB/c mice after intra-nasal infection with Histoplasma capsulatum mycelial propagules.

The host pulmonary response to the fungus Histoplasma capsulatum was evaluated, through the profile of cytokines detected by the MagPix magnetic beads platform in lung homogenates and by lung-granulomas formation, from mice intra-nasally infected with mycelial propagules (M-phase) of two virulent H. capsulatum strains, EH-46 and G-217B. Results highlight that mice lung inflammatory response depends on the H.

Could Histoplasma capsulatum Be Related to Healthcare-Associated Infections?

Healthcare-associated infections (HAI) are described in diverse settings. The main etiologic agents of HAI are bacteria (85%) and fungi (13%). Some factors increase the risk for HAI, particularly the use of medical devices; patients with severe cuts, wounds, and burns; stays in the intensive care unit, surgery, and hospital reconstruction works.

International Society of Human and Animal Mycology (ISHAM)-ITS reference DNA barcoding database--the quality controlled standard tool for routine identification of human and animal pathogenic fungi.

Human and animal fungal pathogens are a growing threat worldwide leading to emerging infections and creating new risks for established ones. There is a growing need for a rapid and accurate identification of pathogens to enable early diagnosis and targeted antifungal therapy. Morphological and biochemical identification methods are time-consuming and require trained experts.

Usefulness of the murine model to study the immune response against Histoplasma capsulatum infection.

The present paper is an overview of the primary events that are associated with the histoplasmosis immune response in the murine model. Valuable data that have been recorded in the scientific literature have contributed to an improved understanding of the clinical course of this systemic mycosis, which is caused by the dimorphic fungus Histoplasma capsulatum. Data must be analyzed carefully, given that misinterpretation could be generated because most of the available information is based on experimental host-parasite interactions that used inappropriate proceedings, i.

Histoplasma capsulatum and Pneumocystis spp. co-infection in wild bats from Argentina, French Guyana, and Mexico.

Background: Histoplasma capsulatum and Pneumocystis organisms cause host infections primarily affecting the lung tissue. H. capsulatum is endemic in the United States of America and Latin American countries.