Adherence of Candida albicans germ tubes to murine tissues in an ex vivo assay

1994 ◽  
Vol 40 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Jose Luis López-Ribot ◽  
Maria Novella Vespa ◽  
W. LaJean Chaffin

Adhesion of Candida albicans germ tubes to murine tissues was examined. An ex vivo assay previously employed to examine adhesion of yeast cells of C. albicans was adapted for use with germ tubes. Binding of germ tubes to kidney, liver, spleen, and lymph node tissues was found to occur throughout the tissue section, with little tissue morphologic specificity. In general, more organisms adhered to spleen and lymph node tissues than to kidney and liver tissues. Observation of adhesion with scanning electron microscopy showed three germ tube – tissue interactions described as loose, tight, or embedded.Key words: Candida, germ tubes, adhesion, ex vivo.

1980 ◽  
Vol 26 (1) ◽  
pp. 21-26 ◽  
Author(s):  
M. G. Shepherd ◽  
Chiew Yoke Yin ◽  
S. P. Ram ◽  
P. A. Sullivan

A reproducible and simple system for the production of germ tubes from yeast cells of Candida albicans using glucose and glutamine as substrates has been described.During germ tube formation there was a doubling of the dry weight but the number of cells remained constant. Although the DNA content did not change for the first 4 h of germ tube formation, the RNA content more than doubled. The DNA and RNA content of C. albicans blastospores are 4.5 × 10−15 g per cell and 48 × 10−15 g per cell respectively.Nystatin, phenethyl alcohol, 2,4-dinitrophenol, azaserine, salicylhydroxamic acid, and 5-fluorocytosine were all effective inhibitors of germ tube formation. Cysteine, potassium cyanide, and polyoxin D did not prevent germination. The incorporation of both uracil and leucine occurred rapidly during germ tube formation. The inhibitors of RNA synthesis, actinomycin D, cordycepin, and daunomycin prevented germination and inhibited uracil incorporation. The translational inhibitors, trichodermin, aurin tricarboxylic acid, puromycin, and cyloheximide were effective in inhibiting both germ tube formation and leucine incorporation.


1982 ◽  
Vol 28 (10) ◽  
pp. 1119-1126 ◽  
Author(s):  
M. Bastide ◽  
S. Jouvert ◽  
J.-M. Bastide

The early events in the interaction of two polyene (amphotericin B and nystatin) and five imidazole (clotrimazole, ketoconazole, miconazole, isoconazole, and econazole) antimycotics used at fungicidal concentrations with the surface of Candida albicans were studied by scanning electron microscopic examination of treated intact young yeast cells, treated spheroplasts, and spheroplasts liberated from treated young yeast cells. In all cases, treatment lasted 2 h. The polyenes passed through the yeast cell wall and interacted with the cytoplasmic membrane causing the spheroplasts to lose their characteristic spheric form and to liberate their contents. Clotrimazole caused the formation of numerous circular openings in the cytoplasmic membrane, but only when the agent was used to treat spheroplasts directly. Ketoconazole, miconazole, isoconazole, and econazole interacted with the cell wall causing formation of convolutions and wrinkles. The three imidazole derivatives that are structurally closely related, miconazole, isoconazole, and econazole, inhibited the enzyme-catalyzed release of spheroplasts from young yeast cells.


1990 ◽  
Vol 36 (4) ◽  
pp. 249-253 ◽  
Author(s):  
Ruth C. Mock ◽  
Jordan H. Pollack ◽  
Tadayo Hashimoto

Candida albicans formed germ tubes when exposed to air containing 5 to 15% carbon dioxide (CO2). The CO2-mediated germ tube formation occurred optimally at 37 °C in a pH range of 5.5 to 6.5. No germ tubes were produced at 25 °C, even when the optimal concentration of CO2 (10%) was present in the environment. The requirement of CO2 for germ tube formation could be partially substituted by sodium bicarbonate but not by N2. Carbon dioxide was required to be present throughout the entire course of germ tube emergence suggesting that its role is not limited to an initial triggering of morphogenic change. We suggest that carbon dioxide may be a common effector responsible for the germ tube promoting activity of certain chemical inducers for C. albicans. Key words: Candida albican germ tubes, CO2-induced germ tube formation, endotrophic germ tube formation.


1970 ◽  
Vol 48 (9) ◽  
pp. 1692-1692 ◽  
Author(s):  
Y. Hiratsuka

Germ tubes of Cronartium coleosporioides Arth. (= Peridermium stalactiforme Arth. and Kern) emerged between processes through short irregular slits. Germ tube walls were folded when they emerged and expanded after the emergence.


1981 ◽  
Vol 27 (6) ◽  
pp. 580-585 ◽  
Author(s):  
Louise A. Brown ◽  
W. LaJean Chaffin

Changes in the identity and quantity of proteins synthesized during morphogenesis may result from alterations in gene expression in the dimorphic yeast Candida albicans. Stationary phase yeast cells, upon resuming growth at 25 °C, form budding yeast and at 37 °C form germ tubes. In order to identify proteins associated with morphogenesis, we compared cytoplasmic proteins synthesized during germ tube and bud formation. Proteins synthesized during this period were labeled at four intervals with either [3H]leucine or [35S]methionine and separated by two-dimensional polyacrylamide gel electrophoresis. This study shows that, of the 230 proteins resolved on each gel, 5 were specific to the yeast morphology and 2 proteins showed reduction in net synthesis in the mycelial phase. There were, however, no mycelium-specific proteins at any labeling period. The majority of proteins were common to both morphologies and showed no major shift in number during resumption of growth. The observations reported here suggest that differential gene expression occurs during morphogenesis of C. albicans.


1971 ◽  
Vol 17 (7) ◽  
pp. 851-856 ◽  
Author(s):  
D. N. Mardon ◽  
I. S. K. Hurst ◽  
E. Balish

Candida albicans formed germ tubes within 3 h at 37C in a glucose–salts–biotin (GSB) medium containing L-alpha-amino-n-butyric acid as the nitrogen source. Optimal germ-tube production was obtained when the inoculum was grown on Sabouraud dextrose agar. The GSB medium containing L-alpha-amino-n-butyric acid promoted germ-tube formation more effectively than GSB medium plus gamma-amino-butyric acid or Sabouraud dextrose broth.Carbon-14 incorporation studies revealed that during germ-tube formation (0–4 h) the 3 carbon of alpha-amino-n-butyric acid was incorporated intracellularly to a greater extent than the 1 carbon. However, during blastospore formation (5–16 h), this difference was less pronounced.When six other Candida species were grown in GSB plus L-alpha-amino-n-butyric acid medium, few germ tubes were observed with the exception of one Candida stellatoidea strain. However, even this strain of C. stellatoidea produced far fewer germ tubes in this minimal culture medium than any strain of C. albicans tested.


Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2223-2232 ◽  
Author(s):  
Nozomu Hanaoka ◽  
Takashi Umeyama ◽  
Keigo Ueno ◽  
Kenji Ueda ◽  
Teruhiko Beppu ◽  
...  

In response to stimulants, such as serum, the yeast cells of the opportunistic fungal pathogen Candida albicans form germ tubes, which develop into hyphae. Yvh1p, one of the 29 protein phosphatases encoded in the C. albicans genome, has 45 % identity with the dual-specific phosphatase Yvh1p of the model yeast Saccharomyces cerevisiae. In this study, Yvh1p expression was not observed during the initial step of germ tube formation, although Yvh1p was expressed constitutively in cell cycle progression of yeast or hyphal cells. In an attempt to analyse the function of Yvh1p phosphatase, the complete ORFs of both alleles were deleted by replacement with hph200–URA3–hph200 and ARG4. Although YVH1 has nine single-nucleotide polymorphisms in its coding sequence, both YVH1 alleles were able to complement the YVH1 gene disruptant. The vegetative growth of Δyvh1 was significantly slower than the wild-type. The hyphal growth of Δyvh1 on agar, or in a liquid medium, was also slower than the wild-type because of the delay in nuclear division and septum formation, although germ tube formation was similar between the wild-type and the disruptant. Despite the slow hyphal growth, the expression of several hypha-specific genes in Δyvh1 was not delayed or repressed compared with that of the wild-type. Infection studies using mouse models revealed that the virulence of Δyvh1 was less than that of the wild-type. Thus, YVH1 contributes to normal vegetative yeast or hyphal cell cycle progression and pathogenicity, but not to germ tube formation.


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