The Experts below are selected from a list of 11076 Experts worldwide ranked by ideXlab platform
Joshua D. Nosanchuk - One of the best experts on this subject based on the ideXlab platform.
-
concentration dependent protein loading of extracellular vesicles released by histoplasma Capsulatum after antibody treatment and its modulatory action upon macrophages
Scientific Reports, 2018Co-Authors: Ludmila Matos Baltazar, Daniel Zamithmiranda, Meagan C Burnet, Hyungwon Choi, Leonardo Nimrichter, Ernesto S Nakayasu, Joshua D. NosanchukAbstract:Diverse pathogenic fungi secrete extracellular vesicles (EV) that contain macromolecules, including virulence factors that can modulate the host immune response. We recently demonstrated that the binding of monoclonal antibodies (mAb) modulates how Histoplasma Capsulatum load and releases its extracellular vesicles (EV). In the present paper, we addressed a concentration-dependent impact on the fungus' EV loading and release with different mAb, as well as the pathophysiological role of these EV during the host-pathogen interaction. We found that the mAbs differentially regulate EV content in concentration-dependent and independent manners. Enzymatic assays demonstrated that laccase activity in EV from H. Capsulatum opsonized with 6B7 was reduced, but urease activity was not altered. The uptake of H. Capsulatum by macrophages pre-treated with EV, presented an antibody concentration-dependent phenotype. The intracellular killing of yeast cells was potently inhibited in macrophages pre-treated with EV from 7B6 (non-protective) mAb-opsonized H. Capsulatum and this inhibition was associated with a decrease in the reactive-oxygen species generated by these macrophages. In summary, our findings show that opsonization quantitatively and qualitatively modifies H. Capsulatum EV load and secretion leading to distinct effects on the host's immune effector mechanisms, supporting the hypothesis that EV sorting and secretion are dynamic mechanisms for a fine-tuned response by fungal cells.
-
Surface architecture of Histoplasma Capsulatum
Frontiers in Microbiology, 2011Co-Authors: Allan J. Guimarães, Mariana Duarte De Cerqueira, Joshua D. NosanchukAbstract:The dimorphic fungal pathogen Histoplasma Capsulatum is the most frequent cause of clinically significant fungal pneumonia in humans. H. Capsulatum virulence is achieved, in part, through diverse and dynamic alterations to the fungal cell surface. Surface components associated with H. Capsulatum pathogenicity include carbohydrates, lipids, proteins, and melanins. Here, we describe the various structures comprising the cell surface of H. Capsulatum that have been associated with virulence and discuss their involvement on the pathobiology of disease.
-
Histoplasma Capsulatum at the host–pathogen interface
Microbes and Infection, 2008Co-Authors: Joshua D. Nosanchuk, Attila GácserAbstract:Histoplasma Capsulatum is the most common cause of invasive fungal pulmonary disease worldwide. The interaction of H. Capsulatum with a host is a complex, dynamic process. Severe disease most commonly occurs in individuals with compromised immunity, and the increasing utilization of immunomodulators in medicine has revealed significant risks for reactivation disease in patients with latent histoplasmosis. Fortunately, there are well developed molecular tools and excellent animal models for studying H. Capsulatum virulence and numerous recent advances have been made regarding the pathogenesis of this fungus that will improve our capacity to combat disease.
-
histoplasma Capsulatum synthesizes melanin like pigments in vitro and during mammalian infection
Infection and Immunity, 2002Co-Authors: Joshua D. Nosanchuk, Angela Restrepo, Beatriz L Gomez, Sirida Youngchim, Soraya Diez, Philip Aisen, Rosely Maria Zancopeoliveira, Arturo Casadevall, A HamiltonAbstract:ABSTRACT Melanin is made by several important pathogenic fungi and has been implicated in the pathogenesis of a number of fungal infections. This study investigated whether the thermally dimorphic fungal pathogen Histoplasma Capsulatum var. Capsulatum produced melanin or melanin-like compounds in vitro and during infection. Growth of H. Capsulatum mycelia in chemically defined minimal medium produced pigmented conidia. Growth of H. Capsulatum yeast in chemically defined minimal medium with l-3,4-dihydroxyphenylalanine (DOPA) or (-)-epinephrine produced pigmented cells. Treatment of the pigmented cells with proteolytic enzymes, denaturant, and hot concentrated acid yielded dark particles that were similar in size and shape to their respective propagules. Melanin-binding monoclonal antibodies (MAb) labeled pigmented conidia, yeast, and the isolated particles as determined by immunofluorescence microscopy. Electron spin resonance spectroscopy revealed that pigmented yeast cells and particles derived from pigmented cells were stable free radicals consistent with their identification as melanins. Tissues from mice infected with H. Capsulatum and from biopsy specimens from a patient with histoplasmosis contained fungal cells that were labeled by melanin-binding MAb. Digestion of infected mouse tissues yielded dark particles that reacted with the melanin-binding MAb and were similar in appearance to H. Capsulatum yeast cells. Additionally, sera from infected mice contained antibodies that bound melanin particles. Phenoloxidase activity capable of synthesizing melanin from L-DOPA was detected in cytoplasmic yeast cell extracts. These findings indicate that H. Capsulatum conidia and yeast can produce melanin or melanin-like compounds in vitro and that yeast cells can synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may have a similar role to play in the pathogenesis of histoplasmosis.
Poorani Sekar - One of the best experts on this subject based on the ideXlab platform.
-
A case of Histoplasma Capsulatum variety Capsulatum septic arthritis successfully treated with surgery, systemic antifungals, and local amphotericin cement beads.
International Journal of Infectious Diseases, 2018Co-Authors: Jocelyn Compton, Wyatt Vander Voort, Michael Willey, Poorani SekarAbstract:Abstract Histoplasma Capsulatum variety Capsulatum (H. Capsulatum) is a thermally dimorphic fungus that is endemic to the Mississippi River and Ohio River valley regions. Of the hundreds of thousands of patients exposed to this fungus, less than 1% develop a severe illness most commonly manifesting as pulmonary disease. Septic arthritis from hematogenous seeding with H. Capsulatum or from direct inoculation has been reported only rarely in the literature. The first case of septic arthritis of the shoulder due to H. Capsulatum occurring in an immunocompromised patient, treated successfully with irrigation and debridement, systemic antifungals, and local delivery of amphotericin B with cement beads, is reported here. Importantly, the addition of local amphotericin B delivery by cement beads to conventional treatment likely led to clinical cure in this patient.
-
A case of Histoplasma Capsulatum variety Capsulatum septic arthritis successfully treated with surgery, systemic antifungals, and local amphotericin cement beads
Elsevier, 2018Co-Authors: Jocelyn Compton, Wyatt Vander Voort, Michael Willey, Poorani SekarAbstract:Histoplasma Capsulatum variety Capsulatum (H. Capsulatum) is a thermally dimorphic fungus that is endemic to the Mississippi River and Ohio River valley regions. Of the hundreds of thousands of patients exposed to this fungus, less than 1% develop a severe illness most commonly manifesting as pulmonary disease. Septic arthritis from hematogenous seeding with H. Capsulatum or from direct inoculation has been reported only rarely in the literature. The first case of septic arthritis of the shoulder due to H. Capsulatum occurring in an immunocompromised patient, treated successfully with irrigation and debridement, systemic antifungals, and local delivery of amphotericin B with cement beads, is reported here. Importantly, the addition of local amphotericin B delivery by cement beads to conventional treatment likely led to clinical cure in this patient. Keywords: Histoplasma Capsulatum, Fungal arthritis, Rheumatoid arthritis, Septic arthritis, Antifungal
Jocelyn Compton - One of the best experts on this subject based on the ideXlab platform.
-
A case of Histoplasma Capsulatum variety Capsulatum septic arthritis successfully treated with surgery, systemic antifungals, and local amphotericin cement beads.
International Journal of Infectious Diseases, 2018Co-Authors: Jocelyn Compton, Wyatt Vander Voort, Michael Willey, Poorani SekarAbstract:Abstract Histoplasma Capsulatum variety Capsulatum (H. Capsulatum) is a thermally dimorphic fungus that is endemic to the Mississippi River and Ohio River valley regions. Of the hundreds of thousands of patients exposed to this fungus, less than 1% develop a severe illness most commonly manifesting as pulmonary disease. Septic arthritis from hematogenous seeding with H. Capsulatum or from direct inoculation has been reported only rarely in the literature. The first case of septic arthritis of the shoulder due to H. Capsulatum occurring in an immunocompromised patient, treated successfully with irrigation and debridement, systemic antifungals, and local delivery of amphotericin B with cement beads, is reported here. Importantly, the addition of local amphotericin B delivery by cement beads to conventional treatment likely led to clinical cure in this patient.
-
A case of Histoplasma Capsulatum variety Capsulatum septic arthritis successfully treated with surgery, systemic antifungals, and local amphotericin cement beads
Elsevier, 2018Co-Authors: Jocelyn Compton, Wyatt Vander Voort, Michael Willey, Poorani SekarAbstract:Histoplasma Capsulatum variety Capsulatum (H. Capsulatum) is a thermally dimorphic fungus that is endemic to the Mississippi River and Ohio River valley regions. Of the hundreds of thousands of patients exposed to this fungus, less than 1% develop a severe illness most commonly manifesting as pulmonary disease. Septic arthritis from hematogenous seeding with H. Capsulatum or from direct inoculation has been reported only rarely in the literature. The first case of septic arthritis of the shoulder due to H. Capsulatum occurring in an immunocompromised patient, treated successfully with irrigation and debridement, systemic antifungals, and local delivery of amphotericin B with cement beads, is reported here. Importantly, the addition of local amphotericin B delivery by cement beads to conventional treatment likely led to clinical cure in this patient. Keywords: Histoplasma Capsulatum, Fungal arthritis, Rheumatoid arthritis, Septic arthritis, Antifungal
Jon P. Woods - One of the best experts on this subject based on the ideXlab platform.
-
Typing of Histoplasma Capsulatum strains by fatty acid profile analysis.
Journal of Medical Microbiology, 2007Co-Authors: Robert Zarnowski, Makoto Miyazaki, Agnieszka Dobrzyn, James M. Ntambi, Jon P. WoodsAbstract:The performance of fatty acid profiling for strain differentiation of Histoplasma Capsulatum was assessed. Total fatty acids were isolated from the yeast-phase cells of seven stock and two previously unreported clinical strains of H. Capsulatum var. Capsulatum, as well as from one unreported clinical strain and one stock strain of H. Capsulatum var. duboisii, and one strain of each of three other dimorphic zoopathogenic fungal species, Blastomyces dermatitidis, Paracoccidioides brasiliensis and Sporothrix schenckii. Different colony morphology and pigmentation types of the H. Capsulatum strains were also included. The most frequently occurring fatty acids were oleic, palmitic, stearic and linoleic acids. There were variations in the relative percentage fatty acid contents of H. Capsulatum strains that could be used for strain identification and discrimination. Differentiation between H. Capsulatum strains was achieved by the comparison of detected fatty acids accompanied by principal component analysis using calculated Varimax-rotated principal component loadings. Statistical analysis yielded three major principal components that explained over 94% of total variance in the data. All the strains of H. Capsulatum var. Capsulatum RFLP classes II and III were grouped into two distinct clusters: the heterogenic RFLP class I formed a large, but also well-defined group, whereas the outgroup strains of H. Capsulatum var. duboisii, B. dermatitidis, P. brasiliensis and S. schenckii were shifted away. These data suggest that fatty acid profiling can be used in H. Capsulatum strain classification and epidemiological studies that require strain differentiation at the intraspecies level.
-
knocking on the right door and making a comfortable home histoplasma Capsulatum intracellular pathogenesis
Current Opinion in Microbiology, 2003Co-Authors: Jon P. WoodsAbstract:Histoplasma Capsulatum is a successful intracellular pathogen of mammalian macrophages. As such, this fungus must survive and/or subvert hostile environmental onslaughts in a professionally antimicrobial host cell. H. Capsulatum uses different host receptors for binding to macrophages (beta 2 integrins) than it uses for binding to dendritic cells (the fibronectin receptor); the fungus experiences different degrees of success in survival in these two cells. Surface expression of HSP60 as the specific adhesin for macrophage beta 2 integrins represents a novel mechanism for binding. Long considered a resident of the phagolysosome, H. Capsulatum may also reside in a modified phagosome without experiencing phagolysosomal fusion. H. Capsulatum must compete with the host to acquire the essential nutrient iron, and has several potential mechanisms for accomplishing this necessary feat. Finally, H. Capsulatum displays morphotype-specific expression of several genes, and a calcium-binding protein expressed only by the pathogenic yeast phase has been demonstrated as essential for full virulence. An organism's environment is of great importance to its success or failure, and H. Capsulatum is good at finding or making the right environment in the host.
Junzhi Wang - One of the best experts on this subject based on the ideXlab platform.
-
genome sequencing and comparative genomics analysis revealed pathogenic potential in penicillium Capsulatum as a novel fungal pathogen belonging to eurotiales
Frontiers in Microbiology, 2016Co-Authors: Ying Yang, Abdullah M S Alhatmi, Xiaochen Bo, Sybren De Hoog, Zongwei Li, Shengqi Wang, Qiang Ye, Zhen Li, Junzhi WangAbstract:Penicillium Capsulatum is a rare Penicillium species used in paper manufacturing, but recently it has been reported to cause invasive infection. To research the pathogenicity of the clinical Penicillium strain, we sequenced the genomes and transcriptome of the clinical and environmental strains of P. Capsulatum. Comparative analyses of these two P. Capsulatum strains and close related strains belonging to Eurotiales were performed. The assembled genome sizes of P. Capsulatum are approximately 34.4 Mbp in length and encode 11,080 predicted genes. The different isolates of P. Capsulatum are highly similar, with the exception of several unique genes, INDELs or SNP in the genes coding for glycosyl hydrolases, amino acid transporters and circumsporozoite protein. A phylogenomic analysis was performed based on the whole genome data of 38 strains belonging to Eurotiales. By comparing the whole genome sequences and the virulence-related genes from 20 important related species, including fungal pathogens and non-human pathogens belonging to Eurotiales, we found meaningful pathogenicity characteristics between P. Capsulatum and its closely related species. Our research indicated that P. Capsulatum may be a neglected opportunistic pathogen. This study is beneficial for mycologists, geneticists and epidemiologists to achieve a deeper understanding of the genetic basis of the role of P. Capsulatum as a newly reported fungal pathogen.