Electron microscopic study of conidia produced by the mycelium of Paracoccidioides brasiliensis

Edwards, Mercedes R.; Salazar, María Elena; Samsonoff, William A.; Cano, Luz Elena; Ostrander, G. A.; Restrepo, Ángela

doi:10.1007/bf00437210

Cited by 14 publications

(10 citation statements)

References 18 publications

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“…These propagules are shown in Fig. 2 by a coat of delicate microfibrils (93). These findings indicate that the propagules are well equipped to survive environmental stress.…”

Section: Etiologic Agentmentioning

confidence: 71%

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Paracoccidioidomycosis: an update

1993

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This review summarizes knowledge on various aspects of paracoccidioidomycosis. Mycelial propagules, chlamydospores, and arthroconidia exhibit thermal dimorphism; arthroconidia are infectious in animals and, by electron microscopy, appear well provided for survival. The mycelial-to-yeast-phase transformation requires a strict control of glucan synthesis probably mediated by membrane enzymes. Hormonal influences on the transformation of the fungus (mycelium or conidium to yeast phase) have been demonstrated. Estrogen-binding proteins have been detected in the fungal cytosol, and during the transformation novel proteins are produced as a result of estradiol incorporation. Clinical forms have been better defined on the basis of better experimental models. Emphasis has been placed on the lungs as the portal of entry and on the existence of silent pulmonary infections. A specific Paracoccidioides brasiliensis antigen, the 43-kDa glycoprotein (Gp43), has been identified, characterized, and cloned. This has led to improved reproducibility and specificity of serologic tests. The depression of cell-mediated immune responses has been associated with severe disease in humans and in the experimental host. T-cell subsets in patients' tissues were characterized by means of monoclonal antibodies, and a reduced CD4/CD8 ratio was demonstrated. This has been related to alterations in lymphokine and tumor necrosis factor production, production of antigen-antibody complexes, etc. Amphotericin B has provided effective therapy. Azole derivatives have also improved prognosis and facilitated therapy. Itraconazole is presently the drug of choice, yet incapacitating sequelae (mainly pulmonary fibrosis) still constitute major problems.

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“…These propagules are shown in Fig. 2 by a coat of delicate microfibrils (93). These findings indicate that the propagules are well equipped to survive environmental stress.…”

Section: Etiologic Agentmentioning

confidence: 71%

“…A variety of conidial types is produced (intercalary arthroconidia; septate, pedunculate conidia; and terminal hyphal conidia) (93,285). These propagules are shown in Fig.…”

Section: Etiologic Agentmentioning

confidence: 99%

Paracoccidioidomycosis: an update

1993

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“…In yeasts, an electron dense outer layer decorated with fibrils covered this inner layer. Conidia cell walls (150 to 300-nm wide) were studied only later: they showed homogeneous appearance of medium electron density, being surrounded by a thick coat of long electron dense microfibrils (Edwards et al, 1991). …”

mentioning

confidence: 99%

The Paracoccidioides Cell Wall: Past and Present Layers Toward Understanding Interaction with the Host

Puccia¹,

Vallejo²,

Matsuo³

et al. 2011

Front. Microbio.

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The cell wall of pathogenic fungi plays import roles in the interaction with the host, so that its composition and structure may determine the course of infection. Here we present an overview of the current and past knowledge on the cell wall constituents of Paracoccidioides brasiliensis and P. lutzii. These are temperature-dependent dimorphic fungi that cause paracoccidioidomycosis, a systemic granulomatous, and debilitating disease. Focus is given on cell wall carbohydrate and protein contents, their immune-stimulatory features, adhesion properties, drug target characteristics, and morphological phase specificity. We offer a journey toward the future understanding of the dynamic nature of the cell wall and of the changes that may occur when the fungus infects the human host.

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“…The cells of C. lunatus m118 are morphologically easily distinguishable from C. lunata AT46, having both thicker hyphae and cell walls, as well as more differentiated cytoplasm containing numerous lipid bodies. However, thick cell walls and large lipid bodies were also observed in older conidiae of different mycelial forms of other fungi [11].…”

Section: Discussionmentioning

confidence: 99%

Ultrastructure and genotypic characterization of the filamentous fungus Cochliobolus lunatus in comparison to the anamorphic strain Curvularia lunata

Rozman¹

1994

FEMS Microbiology Letters

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Although Curvularia lunata is classified as a conidial anamorph of Cochliobolus lunatus, the electron microscopic studies revealed the ultrastructure of both strains to be significantly different. C. lunatus m118 grows in the hyphal form characterized by a thick cell wall and numerous lipid bodies. C. lunata forms thinner hyphae of various sizes and large oval spores. Electrophoretic karyotypes of C. lunatus m118 (this paper) and C. lunata AT46 (Osiewacz, H. and Ridder, R. (1991) Curr. Genet. 20, 151–155) as well as RAPD‐PCR analysis with the primer (GTG)5 indicate close genetic relationship of both microorganisms.

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Electron microscopic study of conidia produced by the mycelium of Paracoccidioides brasiliensis

Cited by 14 publications

References 18 publications

Paracoccidioidomycosis: an update

Paracoccidioidomycosis: an update

The Paracoccidioides Cell Wall: Past and Present Layers Toward Understanding Interaction with the Host

Ultrastructure and genotypic characterization of the filamentous fungus Cochliobolus lunatus in comparison to the anamorphic strain Curvularia lunata

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