scholarly journals Influences of the Culturing Media in the Virulence and Cell Wall of Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa

2020 ◽  
Vol 6 (4) ◽  
pp. 323
Author(s):  
Nancy E. Lozoya-Pérez ◽  
Diana M. Clavijo-Giraldo ◽  
Iván Martínez-Duncker ◽  
Laura C. García-Carnero ◽  
Luz A. López-Ramírez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Nitrogen Limitation ◽  
Galleria Mellonella ◽  
Sporothrix Schenckii ◽  
Fungal Growth ◽  
Cell Preparation ◽  
Fungal Cell ◽  
Minimal Impact ◽  
Sporothrix Globosa ◽  
Sporothrix Brasiliensis

Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa are etiological agents of sporotrichosis, a human subcutaneous mycosis. Although the protocols to evaluate Sporothrix virulence in animal models are well described, the cell preparation before inoculation is not standardized, and several culturing media are used to grow yeast-like cells. Here, we found that carbon or nitrogen limitation during fungal cell preparation negatively impacted the ability of S. schenckii and S. brasiliensis to kill Galleria mellonella larvae, but not S. globosa. The fungal growth conditions associated with the short median survival of animals were accompanied by increased hemocyte countings, phenoloxidase activity, and cytotoxicity. The fungal growth under carbon or nitrogen limitation also affected the cell wall composition of both S. schenckii and S. brasiliensis and showed increased exposure of β-1,3-glucan at the cell surface, while those growing conditions had a minimal impact on the S.globosa wall, which had higher levels of this polysaccharide exposed on the wall regardless of the culture condition. This polysaccharide exposure was linked to the increased ability of insect hemocytes to uptake fungal cells, suggesting that this is one of the mechanisms behind the lower virulence of S.globosa or cells from the other species grown in carbon or nitrogen limitation.

scholarly journals Human Antibodies against a Purified Glucosylceramide from Cryptococcus neoformans Inhibit Cell Budding and Fungal Growth

2000 ◽  
Vol 68 (12) ◽  
pp. 7049-7060 ◽  
Author(s):  
Marcio L. Rodrigues ◽  
Luiz R. Travassos ◽  
Kildare R. Miranda ◽  
Anderson J. Franzen ◽  
Sonia Rozental ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Wall ◽  
Cryptococcus Neoformans ◽  
High Performance ◽  
Fungal Growth ◽  
Fungal Cell ◽  
Human Antibodies ◽  
Different Strains ◽  
Immunofluorescence Labeling

ABSTRACT A major ceramide monohexoside (CMH) was purified from lipidic extracts of Cryptococcus neoformans. This molecule was analyzed by high-performance thin-layer chromatography (HPTLC), gas chromatography coupled with mass spectrometry, and fast atom bombardment-mass spectrometry. The cryptococcal CMH is a β-glucosylceramide, with the carbohydrate residue attached to 9-methyl-4,8-sphingadienine in amidic linkage to 2-hydroxyoctadecanoic acid. Sera from patients with cryptococcosis and a few other mycoses reacted with the cryptococcal CMH. Specific antibodies were purified from patients' sera by immunoadsorption on the purified glycolipid followed by protein G affinity chromatography. The purified antibodies to CMH (mainly immunoglobulin G1) bound to different strains and serological types of C. neoformans, as shown by flow cytofluorimetry and immunofluorescence labeling. Transmission electron microscopy of yeasts labeled with immunogold-antibodies to CMH and immunostaining of isolated cell wall lipid extracts separated by HPTLC showed that the cryptococcal CMH predominantly localizes to the fungal cell wall. Confocal microscopy revealed that the β-glucosylceramide accumulates mostly at the budding sites of dividing cells with a more disperse distribution at the cell surface of nondividing cells. The increased density of sphingolipid molecules seems to correlate with thickening of the cell wall, hence with its biosynthesis. The addition of human antibodies to CMH to cryptococcal cultures of both acapsular and encapsulated strains of C. neoformans inhibited cell budding and cell growth. This process was complement-independent and reversible upon removal of the antibodies. The present data suggest that the cryptococcal β-glucosylceramide is a fungal antigen that plays a role on the cell wall synthesis and yeast budding and that antibodies raised against this component are inhibitory in vitro.

scholarly journals In vitro and in vivo antifungal activity of buparvaquone against Sporothrix brasiliensis

2021 ◽  
Author(s):  
Luana Pereira Borba-Santos ◽  
Thayná Lopes Barreto ◽  
Taissa Vila ◽  
Kung Darh Chi ◽  
Fabiana dos Santos Monti ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Galleria Mellonella ◽  
Fungal Growth ◽  
Sporothrix Brasiliensis ◽  
First Choice ◽  
Altered Cell

Sporotrichosis has become an important zoonosis in Brazil and Sporothrix brasiliensis is the primary species transmitted by cats. Improvement of animal treatment will help control and limit the spread and geographic expansion of sporotrichosis. Accordingly, buparvaquone, an antiprotozoal hydroxynaphthoquinone agent marketed as Butalex®, was evaluated in vitro and in vivo against feline-borne isolates of S. brasiliensis . Buparvaquone inhibited in vitro fungal growth at concentrations 4-fold lower than itraconazole (the first-choice antifungal used for sporotrichosis) and was 408 times more selective for S. brasiliensis than mammalian cells. Yeasts treated with a subinhibitory concentration of buparvaquone exhibited mitochondrial dysfunction, ROS and neutral lipid accumulation, and impaired plasma membranes. Also, scanning electron microscopy images revealed buparvaquone altered cell wall integrity and induced cell disruption. I n vivo experiments in a Galleria mellonella model revealed that buparvaquone (single dose of 5 mg/kg) is more effective than itraconazole against infections with S. brasiliensis yeasts. Combined, our results indicate that buparvaquone has a great in vitro and in vivo antifungal activity against S. brasiliensis , revealing the potential application of this drug as an alternative treatment for feline sporotrichosis.

scholarly journals Comparison of Cell Wall Polysaccharide Composition and Structure Between Strains of Sporothrix schenckii and Sporothrix brasiliensis

2021 ◽  
Vol 12 ◽  
Author(s):  
Héctor L. Villalobos-Duno ◽  
Laura A. Barreto ◽  
Álvaro Alvarez-Aular ◽  
Héctor M. Mora-Montes ◽  
Nancy E. Lozoya-Pérez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sporothrix Schenckii ◽  
Cell Wall Composition ◽  
Cell Wall Polysaccharide ◽  
Sporothrix Brasiliensis ◽  
Composition And Structure ◽  
Causative Agents ◽  
Polysaccharide Composition ◽  
Pathogenic Process

Sporothrix schenckii, Sporothrix brasiliensis, and Sporothrix globosa are the main causative agents of sporotrichosis, a human subcutaneous mycosis. Differences in virulence patterns are associated with each species but remain largely uncharacterized. The S. schenckii and S. brasiliensis cell wall composition and virulence are influenced by the culturing media, with little or no influence on S. globosa. By keeping constant the culturing media, we compared the cell wall composition of three S. schenckii and two S. brasiliensis strains, previously described as presenting different virulence levels on a murine model of infection. The cell wall composition of the five Sporothrix spp. strains correlated with the biochemical composition of the cell wall previously reported for the species. However, the rhamnose-to-β-glucan ratio exhibits differences among strains, with an increase in cell wall rhamnose-to-β-glucan ratio as their virulence increased. This relationship can be expressed mathematically, which could be an important tool for the determination of virulence in Sporothrix spp. Also, structural differences in rhamnomannan were found, with longer side chains present in strains with lower virulence reported for both species here studied, adding insight to the importance of this polysaccharide in the pathogenic process of these fungi.

Analysis of Sporothrix schenckii sensu stricto and Sporothrix brasiliensis virulence in Galleria mellonella

2016 ◽  
Vol 122 ◽  
pp. 73-77 ◽  
Author(s):  
Diana M. Clavijo-Giraldo ◽  
José A. Matínez-Alvarez ◽  
Leila M. Lopes-Bezerra ◽  
Patricia Ponce-Noyola ◽  
Bernardo Franco ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Sporothrix Schenckii ◽  
Sensu Stricto ◽  
Sporothrix Brasiliensis

scholarly journals Involvement of Fungal Cell Wall Components in Adhesion of Sporothrix schenckii to Human Fibronectin

2001 ◽  
Vol 69 (11) ◽  
pp. 6874-6880 ◽  
Author(s):  
Osana C. Lima ◽  
Camila C. Figueiredo ◽  
José O. Previato ◽  
Lucia Mendonça-Previato ◽  
Verônica Morandi ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sporothrix Schenckii ◽  
Matrix Proteins ◽  
Yeast Cells ◽  
Binding Assays ◽  
Fungal Cell ◽  
Host Fungus ◽  
Human Fibronectin ◽  
Dose Dependent ◽  
Cell Surface Glycoconjugates

ABSTRACT Systemic sporotrichosis is an emerging infection potentially fatal for immunocompromised patients. Adhesion to extracellular matrix proteins is thought to play a crucial role in invasive fungal diseases. Here we report studies of the adhesion of Sporothrix schenckii to the extracellular protein fibronectin (Fn). Both yeast cells and conidia of S. schenckii were able to adhere to Fn as detected by enzyme-linked immunosorbent binding assays. Adhesion of yeast cells to Fn is dose dependent and saturable.S. schenckii adheres equally well to 40-kDa and 120-kDa Fn proteolytic fragments. While adhesion to Fn was increased by Ca2+, inhibition assays demonstrated that it was not RGD dependent. A carbohydrate-containing cell wall neutral fraction blocked up to 30% of the observed adherence for the yeast cells. The biochemical nature of this fraction suggests the participation of cell surface glycoconjugates in binding by their carbohydrate or peptide moieties. These results provide new data concerning S. schenckii adhesion mechanisms, which could be important in host-fungus interactions and the establishment of sporotrichosis.

scholarly journals Vesicular Trans-Cell Wall Transport in Fungi: A Mechanism for the Delivery of Virulence-Associated Macromolecules?

2008 ◽  
Vol 2 ◽  
pp. LPI.S1000 ◽  
Author(s):  
Marcio L. Rodrigues ◽  
Leonardo Nimrichter ◽  
Debora L. Oliveira ◽  
Joshua D. Nosanchuk ◽  
Arturo Casadevall
Keyword(s):  
Cell Wall ◽  
Extracellular Vesicles ◽  
Fungal Pathogens ◽  
Histoplasma Capsulatum ◽  
Biological Significance ◽  
Sporothrix Schenckii ◽  
Compositional Analysis ◽  
Fungal Cell ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cellular Origin

Fungal cells are encaged in rigid, complex cell walls. Until recently, there was remarkably little information regarding the trans-fungal cell wall transfer of intracellular macromolecules to the extracellular space. Recently, several studies have begun to elucidate the mechanisms that fungal cells utilize to secrete a wide variety of macromolecules through the cell wall. The combined use of transmission electron microscopy, serology, biochemistry, proteomics and lipidomics have revealed that the fungal pathogens Cryptococcus neoformans, Histoplasma capsulatum, Candida albicans, Candida parapsilosis and Sporothrix schenckii, as well as the model yeast Saccharomyces cerevisiae, each produces extracellular vesicles that carry lipids, proteins, polysaccharides and pigment-like structures of unquestionable biological significance. Compositional analysis of the C. neoformans and H. capsulatum extracellular vesicles suggests that they may function as ‘virulence bags’, with the potential to modulate the host-pathogen interaction in favor of the fungus. The cellular origin of the extracellular vesicles remains unknown, but morphological and biochemical features indicate that they are similar to the well-described mammalian exosomes.

Detection of 2 immunoreactive antigens in the cell wall of Sporothrix brasiliensis and Sporothrix globosa

2014 ◽  
Vol 79 (3) ◽  
pp. 328-330 ◽  
Author(s):  
Estela Ruiz-Baca ◽  
Gustavo Hernández-Mendoza ◽  
Mayra Cuéllar-Cruz ◽  
Conchita Toriello ◽  
Everardo López-Romero ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sporothrix Globosa ◽  
Sporothrix Brasiliensis

scholarly journals Identification and Characterization of a Novel Family of Selective Antifungal Compounds (CANBEFs) That Interfere with Fungal Protein Synthesis

2015 ◽  
Vol 59 (9) ◽  
pp. 5631-5640 ◽  
Author(s):  
Gabriel Mircus ◽  
Nathaniel Albert ◽  
Dafna Ben-Yaakov ◽  
Dodo Chikvashvili ◽  
Yona Shadkchan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Protein Synthesis ◽  
Aspergillus Nidulans ◽  
Galleria Mellonella ◽  
Fungal Infections ◽  
Chemical Compounds ◽  
Fungal Cell ◽  
Content Type ◽  
Mammalian Cell Lines ◽  
Small Chemical

ABSTRACTInvasive mycotic infections have become more common during recent decades, posing an increasing threat to public health. However, despite the growing needs, treatments for invasive fungal infections remain unsatisfactory and are limited to a small number of antifungals. The aim of this study was to identify novel fungal cell wall inhibitors from a library of small chemical compounds using a conditional protein kinase C (PKC)-expressing strain ofAspergillus nidulanssensitive to cell wall-active agents. Eight “hit” compounds affecting cell wall integrity were identified from a screen of 35,000 small chemical compounds. Five shared a common basic molecular structure of 4-chloro-6-arylamino-7-nitro-benzofurazane (CANBEF). The most potent compound, CANBEF-24, was characterized further and was shown to inhibit the growth of pathogenicAspergillus,Candida,Fusarium, andRhizopusisolates at micromolar concentrations but not to affect the growth of mammalian cell lines. CANBEF-24 demonstrated strong synergy in combination with caspofungin, an antifungal that inhibits cell wall biosynthesis. Genetic and biochemical analyses withAspergillus nidulansandSaccharomyces cerevisiaeindicated that CANBEFs selectively inhibit fungal rRNA maturation and protein synthesis, suggesting that their effect on the cell wall is indirect. CANBEFs were nontoxic in insect (Galleria mellonella,Drosophila melanogaster) and mouse models of fungal infection. Preliminary evidence showing no therapeutic benefit in these models suggests that further cycles of optimization are needed for the development of this novel class of compounds for systemic use.

scholarly journals Fungal Cell Wall Septation and Cytokinesis Are Inhibited by Bleomycins

2003 ◽  
Vol 47 (10) ◽  
pp. 3281-3289 ◽  
Author(s):  
Carol W. Moore ◽  
Judith McKoy ◽  
Robert Del Valle ◽  
Donald Armstrong ◽  
Edward M. Bernard ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Division ◽  
Cell Walls ◽  
Intact Cell ◽  
Fungal Growth ◽  
Fungal Cell ◽  
Transmission Electron ◽  
Mother And Daughter ◽  
Fungal Organisms

ABSTRACT When the essential and distinctive cell walls of either pathogenic or nonpathogenic fungi break, cytoplasmic membranes rupture and fungi die. This fungicidal activity was discovered previously on nonproliferating Saccharomyces cerevisiae cells treated briefly with the oxidative tool and anticancer drug family of bleomycins. The present studies investigated effects of bleomycin on growing fungal organisms. These included the medically important Aspergillus fumigatus and Cryptococcus neoformans, as well as the emerging human pathogen and fungal model, S. cerevisiae. Bleomycin had its highest potency against A. fumigatus. Scanning electron microscopy and thin-section transmission electron microscopy were used to study morphological growth characteristics. Killing and growth inhibition were also measured. Long, thin, and segmented hyphae were observed when A. fumigatus was grown without bleomycin but were never observed when the mold was grown with the drug. Bleomycin arrested conidial germination, hyphal development, and the progression and completion of cell wall septation. Similarly, the drug inhibited the construction of yeast cell wall septa, preventing cytokinesis and progression in the cell division cycle of S. cerevisiae. Even when cytoplasms of mother and daughter cells separated, septation and cell division did not necessarily occur. Bizarre cell configurations, abnormally thickened cell walls at mother-daughter necks, abnormal polarized growth, large undivided cells, fragmented cells, and empty cell ghosts were also produced. This is the first report of a fungicidal agent that arrests fungal growth and development, septum formation, and cytokinesis and that also preferentially localizes to cell walls and alters isolated cell walls as well as intact cell walls on nongrowing cells.

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