ON THE CELL WALLS OF DIMORPHIC FUNGI CAUSING SYSTEMIC INFECTIONS

1954 ◽  
Vol 1 (1) ◽  
pp. 1-5 ◽  
Author(s):  
F. Blank
Keyword(s):  
Cell Walls ◽  
Histoplasma Capsulatum ◽  
Paracoccidioides Brasiliensis ◽  
Blastomyces Dermatitidis ◽  
Growth Phases ◽  
Electron Microscopic ◽  
Dimorphic Fungi ◽  
Polymeric Substance ◽  
Systemic Infections ◽  
Microscopic Investigations

Cultures of the mycelial and tissue-like growth phases of Blastomyces dermatitidis, Paracoccidioides brasiliensis, Histoplasma capsulatum, and Sporotrichum Schenckii were extracted and oxidized as described by Scholl in 1908. Debye–Scherrer diagrams of the so prepared cell walls show the presence of chitin in both growth phases of each fungus investigated, and give no evidence of the presence of cellulose or another high polymeric substance in the membranes. Nitrogen determinations of the same material corroborate these findings. Electron-microscopic investigations of the isolated chitin of Blastomyces dermatitidis did not reveal any substantial difference in the submicroscopic structures of the framework of the mycelial and yeast-like growth phases.

scholarly journals In Vitro Activities of Voriconazole, Itraconazole, and Amphotericin B against Blastomyces dermatitidis,Coccidioides immitis, and Histoplasma capsulatum

2000 ◽  
Vol 44 (6) ◽  
pp. 1734-1736 ◽  
Author(s):  
Ren-Kai Li ◽  
Meral A. Ciblak ◽  
Nicole Nordoff ◽  
Lester Pasarell ◽  
David W. Warnock ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Histoplasma Capsulatum ◽  
Clinical Laboratory ◽  
Lethal Effect ◽  
Blastomyces Dermatitidis ◽  
National Committee ◽  
Human Pathogens ◽  
Coccidioides Immitis ◽  
Dimorphic Fungi

ABSTRACT The in vitro activity of voriconazole was compared to those of itraconazole and amphotericin B against the mold forms of 304 isolates of three dimorphic fungi, Blastomyces dermatitidis,Coccidioides immitis, and Histoplasma capsulatum. MICs were determined by a broth microdilution adaptation of the National Committee for Clinical Laboratory Standards M27-A procedure. RPMI 1640 medium was used for tests with voriconazole and itraconazole, whereas Antibiotic Medium 3 with 2% glucose was used for amphotericin B. Minimum fungicidal concentrations (MFCs) were also determined. Amphotericin B was active against all three dimorphic fungi, with MICs at which 90% of the isolates tested are inhibited (MIC90s) of 0.5 to 1 μg/ml. Itraconazole had MIC90s of 0.06 μg/ml for H. capsulatum, 0.125 μg/ml for B. dermatitidis, and 1 μg/ml for C. immitis. The MIC90s of voriconazole were 0.25 μg/ml for all three fungi. Amphotericin B was fungicidal for B. dermatitidis and H. capsulatum with MFCs at which 90% of strains tested are killed (MFC90s) of 0.5 and 2 μg/ml, respectively. It was less active against C. immitis, with MFCs ranging from 0.5 to >16 μg/ml. Voriconazole and itraconazole were lethal for most isolates of B. dermatitidis, with MFC50s and MFC90s of 0.125 and 4 μg/ml, respectively. Both azoles were fungicidal for some isolates of H. capsulatum, with MFC50s of 2 and 8 μg/ml for itraconazole and voriconazole, respectively; neither had a lethal effect upon C. immitis. Our results suggest that voriconazole possesses promising activity against these important human pathogens.

Endemic dimorphic fungi

2017 ◽  
Author(s):  
Angela Restrepo ◽  
Angel A. Gónzalez ◽  
Beatriz L. Gómez
Keyword(s):  
Histoplasma Capsulatum ◽  
Paracoccidioides Brasiliensis ◽  
Fungal Spores ◽  
Coccidioides Immitis ◽  
Dimorphic Fungi ◽  
Clinical Presentations ◽  
Causative Agents ◽  
Risk Patients ◽  
Level 3 ◽  
Biosafety Level

Endemic dimorphic infections are acquired by inhalation of fungal spores which undergo a thermal transition to a yeast-like phase in the host. The causative organisms are geographically restricted and are isolated from the environment; likewise, the infections are associated with people living in, or visiting, these endemic regions. The clinical presentations range from asymptomatic to chronic, and disseminated, depending on the host immune status and other risk factors. The infections and their causative agents are: histoplasmosis (Histoplasma capsulatum), paracoccidioidomycosis (Paracoccidioides brasiliensis/lutzii), blastomycosis (Blastomyces dermatitidis/gilchristii), coccidioidomycosis (Coccidioides immitis/posadasii), talaromycosis (previously penicilliosis; Talaromyces [Penicillium] marneffei), and emmonsiosis (Emmonsia species). Diagnosis relies on microscopy and culture, histology, and immunological detection. Owing to their infectious nature, all of these organisms must be handled using biosafety level-3 containment. Treatment is based around azole administration, usually itraconazole, with amphotericin B for the more severe forms or for the most at risk patients.

scholarly journals Interaction of Blastomyces dermatitidis, Sporothrix schenckii, and Histoplasma capsulatum with Acanthamoeba castellanii

2004 ◽  
Vol 72 (6) ◽  
pp. 3478-3488 ◽  
Author(s):  
Judith N. Steenbergen ◽  
Joshua D. Nosanchuk ◽  
Stephanie D. Malliaris ◽  
Arturo Casadevall
Keyword(s):  
Histoplasma Capsulatum ◽  
Sporothrix Schenckii ◽  
Acanthamoeba Castellanii ◽  
Fungal Growth ◽  
Laboratory Strain ◽  
Yeast Cells ◽  
Blastomyces Dermatitidis ◽  
Mammalian Host ◽  
Human Pathogens ◽  
Dimorphic Fungi

ABSTRACT Several dimorphic fungi are important human pathogens, but the origin and maintenance of virulence in these organisms is enigmatic, since an interaction with a mammalian host is not a requisite for fungal survival. Recently, Cryptococcus neoformans was shown to interact with macrophages, slime molds, and amoebae in a similar manner, suggesting that fungal pathogenic strategies may arise from environmental interactions with phagocytic microorganisms. In this study, we examined the interactions of three dimorphic fungi with the soil amoeba Acanthameobae castellanii. Yeast forms of Blastomyces dermatitidis, Sporothrix schenckii, and Histoplasma capsulatum were each ingested by amoebae and macrophages, and phagocytosis of yeast cells resulted in amoeba death and fungal growth. H. capsulatum conidia were also cytotoxic to amoebae. For each fungal species, exposure of yeast cells to amoebae resulted in an increase in hyphal cells. Exposure of an avirulent laboratory strain of H. capsulatum to A. castellanii selected for, or induced, a phenotype of H. capsulatum that caused a persistent murine lung infection. These results are consistent with the view that soil amoebae may contribute to the selection and maintenance of certain traits in pathogenic dimorphic fungi that confer on these microbes the capacity for virulence in mammals.

Cytochemical localization of peroxidase activity in wound vessel members of Coleus

1972 ◽  
Vol 50 (5) ◽  
pp. 977-983 ◽  
Author(s):  
Peter K. Hepler ◽  
Rita M. Rice ◽  
William A. Terranova
Keyword(s):  
Peroxidase Activity ◽  
Cell Walls ◽  
Secondary Wall ◽  
Primary Wall ◽  
Electron Microscopic ◽  
Cytochemical Localization ◽  
Secondary Thickening ◽  
Vessel Elements ◽  
Microscopic Investigations

Peroxidase activity has been localized in the cell walls and cytoplasm of wound vessel elements of Coleus which had been fixed in glutaraldehyde, incubated in diaminobenzidine (DAB) and H2O2, and postfixed in OSO4. Electron microscopic investigations revealed prominent staining in the reticulate secondary wall and in the primary wall where the secondary thickenings attach. The stain in the secondary wall is finely textured and heavier towards its periphery than towards its core. The staining of the primary wall, however, is coarsely granular. In the cytoplasm of differentiating vessel elements electron-opaque deposits are observed in the plasmalemma, especially where it overlies the secondary thickening, and in the dictyosomes and their associated vesicles. Staining also occurs on the internal membranes of developing chloroplasts where it is most likely the result of photooxidation of DAB.Staining, except in chloroplasts, appears to be due specifically to peroxidase, since either removal of H2O2 or preincubation with KCN markedly reduces staining, whereas preincubation with aminotriazole, an inhibitor of catalase, does not. The similarity of localization of peroxidase and lignin in the walls of Coleus wound vessel elements supports the postulate that the enzyme participates in lignification.

scholarly journals Dimorphic Fungal Coinfection as a Cause of Chronic Diarrhea and Pancolitis

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Eduar A. Bravo ◽  
Arturo J. Zegarra ◽  
Alejandro Piscoya ◽  
José L. Pinto ◽  
Raúl E. de los Rios ◽  
...  
Keyword(s):  
North America ◽  
South America ◽  
Histoplasma Capsulatum ◽  
Chronic Diarrhea ◽  
Paracoccidioides Brasiliensis ◽  
Fungal Diseases ◽  
Systemic Mycosis ◽  
Gastrointestinal Involvement ◽  
Dimorphic Fungi ◽  
Tropical South America

Histoplasma capsulatumandParacoccidioides brasiliensisare dimorphic fungi that cause systemic mycosis mostly in tropical South America and some areas of North America. Gastrointestinal involvement is not uncommon among these fungal diseases, but coinfection has not previously been reported. We report a patient with chronic diarrhea and pancolitis caused by paracoccidioidomycosis and histoplasmosis.

scholarly journals Molecular Genetic Variation in Emmonsia crescens andEmmonsia parva, Etiologic Agents of Adiaspiromycosis, and Their Phylogenetic Relationship to Blastomyces dermatitidis (Ajellomyces dermatitidis) and Other Systemic Fungal Pathogens

1998 ◽  
Vol 36 (10) ◽  
pp. 2918-2925 ◽  
Author(s):  
Stephen W. Peterson ◽  
Lynne Sigler
Keyword(s):  
Genetic Variation ◽  
Dna Sequences ◽  
Fungal Pathogens ◽  
Histoplasma Capsulatum ◽  
Paracoccidioides Brasiliensis ◽  
Large Subunit ◽  
Molecular Genetic ◽  
Blastomyces Dermatitidis ◽  
Internal Transcribed Spacer Region ◽  
Emmonsia Crescens

Emmonsia crescens, an agent of adiaspiromycosis,Blastomyces dermatitidis, the agent of blastomycosis, andHistoplasma capsulatum, the agent of histoplasmosis, are known to form meiotic (sexual) stages in the ascomycete genusAjellomyces (Onygenaceae,Onygenales), but no sexual stage is known for E. parva, the type species of the genus Emmonsia. To evaluate relationships among members of the putativeAjellomyces clade, large-subunit ribosomal and internal transcribed spacer region DNA sequences were determined from PCR-amplified DNA fragments. Sequences were analyzed phylogenetically to evaluate the genetic variation within the genus Emmonsiaand evolutionary relationships to other taxa. E. crescens and E. parva are distinct species.E. crescens isolates are placed into two groups that correlate with their continents of origin. Considerable variation occurred among isolates previously classified as E. parva. Most isolates are placed into two closely related groups, but the remaining isolates, including some from human sources, are phylogenetically distinct and represent undescribed species. Strains ofB. dermatitidis are a sister species of E. parva. Paracoccidioides brasiliensis andHistoplasma capsulatum are ancestral to mostEmmonsia isolates, and P. brasiliensis, which has no known teleomorph, falls within the Ajellomycesclade.

A Correlation between Detergent Tolerance and Cell Wall Structure in Green Algae

1987 ◽  
Vol 42 (3) ◽  
pp. 245-250 ◽  
Author(s):  
Susanne Biedlingmaier ◽  
Gerhard Wanner ◽  
Ahlert Schmidt
Keyword(s):  
Cell Wall ◽  
Chlorophyll Content ◽  
Cell Walls ◽  
Linear Alkylbenzene Sulfonate ◽  
Wall Structure ◽  
Electron Microscopic ◽  
Linear Alkylbenzene ◽  
Chemical Attack ◽  
Alkylbenzene Sulfonate ◽  
Microscopic Investigations

12 strains of the geni Chlorella, Scenedesmus, Chlamydomonas, and Dunaliella were tested for their tolerance against the anionic detergent “LAS” (linear alkylbenzene sulfonate). Cellular parameters (cell titer and chlorophyll content) were monitored for 28 days after addition of LAS (0.01-2 mᴍ). A 100-fold difference in sensitivity toward LAS was detected for the algal strains analyzed. Electron microscopic investigations revealed that LAS-resistance is correlated with both, the presence of thick cell walls and sporopollenin layers. It is speculated that this structure acts as a protecting coat preventing the chemical attack of detergents on algal cells. An application for selecting algae by detergents is proposed.

Lysis of zoopathogenic fungi by streptomycetes

1971 ◽  
Vol 17 (4) ◽  
pp. 521-523 ◽  
Author(s):  
Dexter H. Howard ◽  
Rishab K. Gupta
Keyword(s):  
Yeast Cell ◽  
Cell Walls ◽  
Histoplasma Capsulatum ◽  
Sporothrix Schenckii ◽  
Blastomyces Dermatitidis ◽  
Streptomyces Spp

The cell walls of the yeast cell phases of Histoplasma capsulatum, Blastomyces dermatitidis, and Sporothrix schenckii were lysed by enzymes formed during the growth of Streptomyces spp. Mycelial elements of H. capsulatum were not lysed by the streptomycetes.

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