The structural basis for the serospecificity ofActinobacillus suisserogroup O:2

2006 ◽  
Vol 84 (2) ◽  
pp. 184-190 ◽  
Author(s):  
Anthony Rullo ◽  
Erzsebet Papp-Szabo ◽  
Frank St Michael ◽  
Janet MacInnes ◽  
Mario A Monteiro
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Chemical Structure ◽  
Bacterial Pathogen ◽  
Structural Basis ◽  
Cell Wall Component ◽  
O Antigen ◽  
Actinobacillus Suis ◽  
Glycoconjugate Vaccine

Actinobacillus suis is an important bacterial pathogen of healthly pigs. An O-antigen (lipopolysaccharide; LPS) serotyping system is being developed to study the prevalence and distribution of representative isolates from both healthy and diseased pigs. In a previous study, we reported that A. suis serogroup O:1 strains express LPS with a (1→6)-β-D-glucan O-antigen chain polysaccharide that is similar in structure to a key cell-wall component in yeasts, such as Saccharomyces cerevisiae and Candida albicans. This study describes the O-antigen polysaccharide chemical structure of an O:2 serogroup strain, A. suis H91-0380, which possesses a tetrasaccharide repeating block with the structure: →3)-β-D-Galp-(1→4)-[α-D-Galp-(1→6)]-β-D-Glcp-(1→6)-β-D-GlcpNAc-(1→. Studies have shown that A. suis serogroup O:2 strains are associated with severely diseased animals; therefore, work on the synthesis of a glycoconjugate vaccine employing O:2 O-antigen polysaccharide to vaccinate pigs against A. suis serogroup O:2 strains is currently underway.Key words: Actinobacillus suis, lipopolysaccharide, serogroup O:2, vaccine.

scholarly journals Cell Wall-Related Bionumbers and Bioestimates of Saccharomyces cerevisiae and Candida albicans

2013 ◽  
Vol 13 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Frans M. Klis ◽  
Chris G. de Koster ◽  
Stanley Brul
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cell Size ◽  
Pathogenic Fungus ◽  
Turgor Pressure ◽  
Hyphal Growth ◽  
Biological Research ◽  
Content Type ◽  
Starting Point

ABSTRACTBionumbers and bioestimates are valuable tools in biological research. Here we focus on cell wall-related bionumbers and bioestimates of the budding yeastSaccharomyces cerevisiaeand the polymorphic, pathogenic fungusCandida albicans. We discuss the linear relationship between cell size and cell ploidy, the correlation between cell size and specific growth rate, the effect of turgor pressure on cell size, and the reason why using fixed cells for measuring cellular dimensions can result in serious underestimation ofin vivovalues. We further consider the evidence that individual buds and hyphae grow linearly and that exponential growth of the population results from regular formation of new daughter cells and regular hyphal branching. Our calculations show that hyphal growth allowsC. albicansto cover much larger distances per unit of time than the yeast mode of growth and that this is accompanied by strongly increased surface expansion rates. We therefore predict that the transcript levels of genes involved in wall formation increase during hyphal growth. Interestingly, wall proteins and polysaccharides seem barely, if at all, subject to turnover and replacement. A general lesson is how strongly most bionumbers and bioestimates depend on environmental conditions and genetic background, thus reemphasizing the importance of well-defined and carefully chosen culture conditions and experimental approaches. Finally, we propose that the numbers and estimates described here offer a solid starting point for similar studies of other cell compartments and other yeast species.

Candida albicans and Saccharomyces cerevisiae cell wall mannans produce fever in rats

Life Sciences ◽  
2000 ◽  
Vol 67 (18) ◽  
pp. 2247-2256 ◽  
Author(s):  
Haluk Ataŏglu ◽  
M.Devrim Dŏgan ◽  
Ferhat Mustafa ◽  
Eyup S. Akarsu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans

scholarly journals Nanoscale Effects of Caspofungin against Two Yeast Species, Saccharomyces cerevisiae and Candida albicans

2013 ◽  
Vol 57 (8) ◽  
pp. 3498-3506 ◽  
Author(s):  
C. Formosa ◽  
M. Schiavone ◽  
H. Martin-Yken ◽  
J. M. François ◽  
R. E. Duval ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Yeast Species ◽  
Young Modulus ◽  
Antifungal Drugs ◽  
Molecular Organization ◽  
Response To Treatment ◽  
Content Type ◽  
High Doses

ABSTRACTSaccharomyces cerevisiaeandCandida albicansare model yeasts for biotechnology and human health, respectively. We used atomic force microscopy (AFM) to explore the effects of caspofungin, an antifungal drug used in hospitals, on these two species. Our nanoscale investigation revealed similar, but also different, behaviors of the two yeasts in response to treatment with the drug. While administration of caspofungin induced deep cell wall remodeling in both yeast species, as evidenced by a dramatic increase in chitin and decrease in β-glucan content, changes in cell wall composition were more pronounced withC. albicanscells. Notably, the increase of chitin was proportional to the increase in the caspofungin dose. In addition, the Young modulus of the cell was three times lower forC. albicanscells than forS. cerevisiaecells and increased proportionally with the increase of chitin, suggesting differences in the molecular organization of the cell wall between the two yeast species. Also, at a low dose of caspofungin (i.e., 0.5× MIC), the cell surface ofC. albicansexhibited a morphology that was reminiscent of cells expressing adhesion proteins. Interestingly, this morphology was lost at high doses of the drug (i.e., 4× MIC). However, the treatment ofS. cerevisiaecells with high doses of caspofungin resulted in impairment of cytokinesis. Altogether, the use of AFM for investigating the effects of antifungal drugs is relevant in nanomedicine, as it should help in understanding their mechanisms of action on fungal cells, as well as unraveling unexpected effects on cell division and fungal adhesion.

scholarly journals The Cell Wall-Associated Glyceraldehyde-3-Phosphate Dehydrogenase of Candida albicans Is Also a Fibronectin and Laminin Binding Protein

1998 ◽  
Vol 66 (5) ◽  
pp. 2052-2059 ◽  
Author(s):  
Daniel Gozalbo ◽  
Inés Gil-Navarro ◽  
Inmaculada Azorín ◽  
Jaime Renau-Piqueras ◽  
José P. Martínez ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Glycolytic Enzyme ◽  
Flow Cytometry Analysis ◽  
Western Blot Assay ◽  
Microtiter Plates ◽  
Laminin Binding Protein ◽  
Laminin Binding ◽  
Host Tissues

ABSTRACT By immunoelectron microscopy with a polyclonal antibody against the cytosolic glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Candida albicans (anti-GAPDH PAb), the protein was clearly detected at the outer surface of the cell wall, particularly on blastoconidia, as well as in the cytoplasm. Intact blastoconidia were able to adhere to fibronectin and laminin immobilized on microtiter plates, and this adhesion was markedly reduced by both the anti-GAPDH PAb and soluble GAPDH fromSaccharomyces cerevisiae. In addition, semiquantitative flow cytometry analysis with the anti-GAPDH PAb showed a decrease in antibody binding to cells in the presence of soluble fibronectin and laminin. Purified cytosolic C. albicans GAPDH was found to bind to fibronectin and laminin in a ligand Western blot assay. These observations suggest that the cell wall-associated form of the GAPDH in C. albicans could be involved in mediating adhesion of fungal cells to fibronectin and laminin, thus contributing to the attachment of the microorganism to host tissues and to the dissemination of Candida infection.

Effects of aculeacin A and papulacandin B on Candida albicans

1984 ◽  
Vol 42 ◽  
pp. 706-707
Author(s):  
J. J. Bozzola ◽  
R. J. Mehta
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Fatty Acid ◽  
Plasma Membranes ◽  
Chain Fatty Acid ◽  
Long Chain Fatty Acid ◽  
Chemical Structures ◽  
Aculeacin A ◽  
Long Chain

Aculeacin A1 and papulacandin B2 are closely related antimycotic agents that interfere with the synthesis of alkalai-insoluble β 1-3 glucan in the cell wall of Candida albicans, Saccharomyces cerevisiae and Geotrichum lactis. The chemical structures of both agents contain a long-chain fatty acid, and both agents are strongly inhibitory to C. albicans and some other fungi while having negligible activity against bacteria or protozoa. Earlier studies involving light microscopy of aculeacin A treated cells revealed rounded, distorted cells aggregated in clumps. The sole TEM micrograph of aculeacin A treated cells showed invaginations and globular bodies associated with plasma membranes.

scholarly journals Molecular Analysis of the Candida albicans Homolog of Saccharomyces cerevisiae MNN9, Required for Glycosylation of Cell Wall Mannoproteins

1999 ◽  
Vol 181 (24) ◽  
pp. 7439-7448 ◽  
Author(s):  
Susan B. Southard ◽  
Charles A. Specht ◽  
Chitra Mishra ◽  
Joan Chen-Weiner ◽  
Phillips W. Robbins
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Gene Family ◽  
Molecular Analysis ◽  
Transmembrane Domain ◽  
Antifungal Drugs ◽  
Northern Analysis ◽  
Fungal Cell ◽  
Poor Growth

ABSTRACT The fungal cell wall has generated interest as a potential target for developing antifungal drugs, and the genes encoding glucan and chitin in fungal pathogens have been studied to this end. Mannoproteins, the third major component of the cell wall, contain mannose in either O- or N-glycosidic linkages. Here we describe the molecular analysis of the Candida albicans homolog ofSaccharomyces cerevisiae MNN9, a gene required for the synthesis of N-linked outer-chain mannan in yeast, and the phenotypes associated with its disruption. CaMNN9 has significant homology with S. cerevisiae MNN9, including a putative N-terminal transmembrane domain, and represents a member of a similar gene family in Candida. CaMNN9 resides on chromosome 3 and is expressed at similar levels in both yeast and hyphal cells. Disruption of both copies of CaMNN9 leads to phenotypic effects characteristic of cell wall defects including poor growth in liquid media and on solid media, formation of aggregates in liquid culture, osmotic sensitivity, aberrant hyphal formation, and increased sensitivity to lysis after treatment with β-1,3-glucanase. Like all members of the S. cerevisiae MNN9 gene family theCamnn9Δ strain is resistant to sodium orthovanadate and sensitive to hygromycin B. Analysis of cell wall-associated carbohydrates showed the Camnn9Δ strain to contain half the amount of mannan present in cell walls derived from the wild-type parent strain. Reverse transcription-PCR and Northern analysis of the expression of MNN9 gene family members CaVAN1and CaANP1 in the Camnn9Δ strain showed that transcription of those genes is not affected in the absence ofCaMNN9 transcription. Our results suggest that, while the role MNN9 plays in glycosylation in bothCandida and Saccharomyces is conserved, loss ofMNN9 function in C. albicans leads to phenotypes that are inconsistent with the pathogenicity of the organism and thus identify CaMnn9p as a potential drug target.

scholarly journals GPI7 affects cell-wall protein anchorage in Saccharomyces cerevisiae and Candida albicans

Microbiology ◽  
2002 ◽  
Vol 148 (7) ◽  
pp. 2125-2133 ◽  
Author(s):  
Mathias Richard ◽  
Piet de Groot ◽  
Olivier Courtin ◽  
Daniel Poulain ◽  
Frans Klis ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cell Wall Protein
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