scholarly journals Experimental Germ Tube Induction in Candida albicans: An Evaluation of the Effect of Sodium Bicarbonate on Morphogenesis and Comparison with Pooled Human Serum

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Tapiwa Matare ◽  
Pasipanodya Nziramasanga ◽  
Lovemore Gwanzura ◽  
Valerie Robertson
Keyword(s):  
Candida Albicans ◽  
Human Serum ◽  
Germ Tube ◽  
Tube Formation ◽  
Joint Research ◽  
Significant Difference ◽  
Buffer Control ◽  
Tris Maleate ◽  
Microscope Slides ◽  
Germ Tubes

Objective. The potential of NaHCO3 versus human serum to induce germ tube formation in Candida albicans was investigated. Specimens. A total of 100 isolates were obtained from oral swabs of patients presenting with thrush. Approval for the study was granted by the Joint Research Ethics Committee (JREC/23/08). Method. Confirmed C. albicans isolates by routine methods were tested for germ tube induction using 5 different concentrations of Tris-maleate buffered NaHCO3 and Tris-maleate buffer control. Standard control strains included were C. albicans (ATCC 10231) and C. krusei (ATCC 6258). Microculture was done in 20 μL inoculums on microscope slides for 3 hours at 37°C. The rate of germ tube formation at 10-minute intervals was determined on 100 isolates using the optimum 20 mM Tris-maleate buffered NaHCO3 concentration. Parallel germ tube formation using human serum was done in test tubes. Results. The optimum concentration of NaHCO3 in Tris-maleate buffer for germ tube induction was 20 mM for 67% of isolates. Only 21% of isolates formed germ tubes in Tris-maleate buffer control. There was no significant difference in induction between human serum and Tris-maleate buffered NaHCO3. Conclusion. Tris-maleate buffered NaHCO3 induced germ tube formation in C. albicans isolates at rates similar to human serum.

Carbon dioxide induces endotrophic germ tube formation in Candida albicans

1990 ◽  
Vol 36 (4) ◽  
pp. 249-253 ◽  
Author(s):  
Ruth C. Mock ◽  
Jordan H. Pollack ◽  
Tadayo Hashimoto
Keyword(s):  
Carbon Dioxide ◽  
Candida Albicans ◽  
Sodium Bicarbonate ◽  
Key Words ◽  
Germ Tube ◽  
Tube Formation ◽  
Chemical Inducers ◽  
Tube Emergence ◽  
Ph Range ◽  
Germ Tubes

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.

Germ-tube production by Candida albicans in minimal liquid culture media

1971 ◽  
Vol 17 (7) ◽  
pp. 851-856 ◽  
Author(s):  
D. N. Mardon ◽  
I. S. K. Hurst ◽  
E. Balish
Keyword(s):  
Candida Albicans ◽  
Butyric Acid ◽  
Germ Tube ◽  
Culture Medium ◽  
Culture Media ◽  
Tube Formation ◽  
Gamma Amino Butyric Acid ◽  
Tube Production ◽  
Amino Butyric Acid ◽  
Germ Tubes

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.

scholarly journals Arginine-Induced Germ Tube Formation in Candida albicans Is Essential for Escape from Murine Macrophage Line RAW 264.7

2009 ◽  
Vol 77 (4) ◽  
pp. 1596-1605 ◽  
Author(s):  
Suman Ghosh ◽  
Dhammika H. M. L. P. Navarathna ◽  
David D. Roberts ◽  
Jake T. Cooper ◽  
Audrey L. Atkin ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogen ◽  
Germ Tube ◽  
Tube Formation ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Wild Type ◽  
Normal Flora ◽  
Opportunistic Fungal Pathogen ◽  
Germ Tubes

ABSTRACT The opportunistic fungal pathogen Candida albicans is a part of the normal flora but it also causes systemic candidiasis if it reaches the bloodstream. Upon being phagocytized by macrophages, an important component of innate immunity, C. albicans rapidly upregulates a set of arginine biosynthetic genes. Arginine, urea, and CO2 induced hyphae in a density-dependent manner in wild-type, cph1/cph1, and rim101/rim101 strains but not in efg1/efg1 or cph1/cph1 efg1/efg1 strains. Arginase (Car1p) converts arginine to urea, which in turn is degraded by urea amidolyase (Dur1,2p) to produce CO2, a signal for hyphal switching. We used a dur1,2/dur1,2 mutant (KWN6) and the complemented strain, KWN8 (dur1,2/dur1,2::DUR1,2/DUR1,2) to study germ tube formation. KWN6 could not make germ tubes in the presence of arginine or urea but did in the presence of 5% CO2, which bypasses Dur1,2p. We also tested the effect of arginine on the interaction between the macrophage line RAW 264.7 and several strains of C. albicans. Arginine activated an Efg1p-dependent yeast-to-hypha switch, enabling wild-type C. albicans and KWN8 to escape from macrophages within 6 h, whereas KWN6 was defective in this regard. Additionally, two mutants that cannot synthesize arginine, BWP17 and SN152, were defective in making hyphae inside the macrophages, whereas the corresponding arginine prototrophs, DAY286 and SN87, formed germ tubes and escaped from macrophages. Therefore, metabolism of arginine by C. albicans controls hyphal switching and provides an important mechanism for escaping host defense.

scholarly journals Effects of farnesol and lyticase on the formation of Candida albicans biofilm

2020 ◽  
Vol 13 (6) ◽  
pp. 1030-1036 ◽  
Author(s):  
Nadezhda Sachivkina ◽  
Ekaterina Lenchenko ◽  
Dmitri Blumenkrants ◽  
Alfia Ibragimova ◽  
Olga Bazarkina
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Tube Formation ◽  
Host Cells ◽  
Dimorphic Fungus ◽  
Chromogenic Medium ◽  
Fungal Cell ◽  
Treatment Groups ◽  
Bacterial Enzyme ◽  
Significant Difference

Background and Aim: Candida albicans is a dimorphic fungus that has both yeast and filamentous forms. It is part of the normal flora in the oral and genital areas of mammals. One factor for the pathogenicity of C. albicans is its ability to switch from yeast to hyphae. The hyphal form adheres and penetrates tissues more readily than the yeast form and produces biofilms that are associated with chronic infection. Biofilms are protective niches that enable microorganisms to be more resistant to antibiotic treatment, thus allowing for persistent infection. The first stage in the transition from yeast to hyphae involves the formation of a germ tube, and this transition is triggered by interactions with host cells. Germ tube formation is dependent on serum, pH, temperature, and quorum-sensing molecules (QSMs). Farnesol, which is a QSM in C. albicans, can prevent yeast to hyphae conversion and inhibits the growth of fungal biofilm. Lyticase is a synergistic enzyme complex that catalyzes yeast cell lysis by β-1,3-glucanase and is a highly specific alkaline protease that produces protoplasts or spheroplasts. This study investigated the effect of farnesol and lyticase on the formation of C. albicans biofilms. Materials and Methods: C. albicans ATCC 2091 was cultivated on liquid and solid Sabouraud media. The presence of C. albicans was confirmed using HiCrome Candida Agar chromogenic medium. Enzyme activities were assayed using a HiCandida Identification Kit. The morphology and densitometry parameters of C. albicans biofilms were considered in the presence of farnesol (Sigma-Aldrich, Germany), lyticase (from Arthrobacter luteus; Sigma-Aldrich, Germany), and farnesol–lyticase. Results: This study shows that both farnesol and lyticase possess antifungal activity against C. albicans biofilms. A significant difference among treatment groups (p<0.05) was observed from strong biofilm production to medium and weak. Conclusion: Many studies have been devoted to the antimicrobial action of farnesol. Bacterial enzyme lyticase is also used to degrade fungal cell walls. Both molecules show substantial antifungal properties that are similar to the properties of modern antimycotics. The current study demonstrates that farnesol and lyticase can disrupt biofilm formation in C. albicans ATCC 2091, which is an effective biofilm producer.

Induction of germ tube formation by N-acetyl-D-glucosamine in Candida albicans: uptake of inducer and germinative response

1982 ◽  
Vol 152 (2) ◽  
pp. 555-562
Author(s):  
E Mattia ◽  
G Carruba ◽  
L Angiolella ◽  
A Cassone
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Insoluble Fraction ◽  
Tube Formation ◽  
Uranyl Acetate ◽  
Uptake System ◽  
Low Responders ◽  
Cell Fractions ◽  
Germ Tubes ◽  
High Responders

A number of strains of Candida albicans were tested for germ tube formation after induction by N-acetyl-D-glucosamine (GlcNAc) and other simple (proline, glucose plus glutamine) or complex (serum) compounds. A proportion of strains (high responders) were induced to form germ tubes evolving to true hyphae by GlcNAc alone or by proline or glucose plus glutamine mixture. The majority of strains were low responders because they could be induced only by serum or GlcNAc-serum medium. Two strains were found to be nonresponders: they grew as pseudohyphae in serum. Despite minor quantitative differences, all strains efficiently utilized GlcNAc for growth under the yeast form at 28 degrees C. They also had comparable active, inducible, and constitutive uptake systems for GlcNAc. During germ tube formation in GlcNAc, the inducible uptake system was modulated, as expected from induction and decay of GlcNAc kinase. Uranyl acetate, at a concentration of 0.01 mM, inhibited both GlcNAc uptake and germ tube formation and was reversed by phosphates. Germinating and nongerminating cells differed in the rapidity and extent of GlcNAc incorporation into acid-insoluble and alkali-acid-insoluble cell fractions. During germ tube formation induced by proline, GlcNAc was almost totally incorporated into the acid-insoluble fraction after 60 min. Moreover, hyphal development on induction by either GlcNAc or proline was characterized by an apparent "uncoupling" between protein and polysaccharide metabolism, the ratio between the two main cellular constituents falling from more than 1 to less than 0.5 after 270 min of development. The data suggest that utilization of the inducer for wall synthesis is a determinant of germ tube formation C. albicans but that the nature and extent of inducer uptake is not a key event for this phenomenon to occur.

scholarly journals In Candida albicans, the Nim1 kinases Gin4 and Hsl1 negatively regulate pseudohypha formation and Gin4 also controls septin organization

2004 ◽  
Vol 164 (4) ◽  
pp. 581-591 ◽  
Author(s):  
Raymond Wightman ◽  
Steven Bates ◽  
Pat Amornrrattanapan ◽  
Peter Sudbery
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Ectopic Expression ◽  
Tube Formation ◽  
Septin Ring ◽  
Germ Tubes ◽  
Developmental Switch

In the development of hyphal germ tubes of Candida albicans, a band of septin forms at the base of the germ tube (basal septin band). Later, a septin ring forms, which organizes the first septum within the germ tube (septin ring). We have investigated the role of the Nim1 kinases, Gin4 and Hsl1, in the formation of these septin structures. We show that during germ tube formation, Gin4 is required for the organization of the septin ring but not the basal septin band. Hsl1 is not required for the formation of either septin rings or basal bands. Unexpectedly, we found that both gin4Δ and hsl1Δ mutants form pseudohyphae constitutively, in a fashion that in the case of gin4Δ, is partly independent of Swe1. Gin4-depleted pseudohyphae are unable to form hyphae when challenged with serum, but this can be overcome by ectopic expression of Gin4 from the MET3 promoter. Thus, Gin4 may regulate the developmental switch from pseudohyphae to hyphae.

Germ tube induction in Candida albicans

1980 ◽  
Vol 26 (1) ◽  
pp. 21-26 ◽  
Author(s):  
M. G. Shepherd ◽  
Chiew Yoke Yin ◽  
S. P. Ram ◽  
P. A. Sullivan
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Potassium Cyanide ◽  
Dry Weight ◽  
Tube Formation ◽  
Yeast Cells ◽  
Leucine Incorporation ◽  
Dna And Rna ◽  
Rna Content ◽  
Germ Tubes

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.

scholarly journals Germ tube and chlamydospore formation by Candida albicans on a new medium

1975 ◽  
Vol 2 (4) ◽  
pp. 345-348
Author(s):  
F Beheshti ◽  
A G Smith ◽  
G W Krause
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Practical Importance ◽  
Tween 80 ◽  
Tube Formation ◽  
Sequential Development ◽  
Chlamydospore Formation ◽  
Clinical Mycology ◽  
Germ Tubes ◽  
Mycology Laboratory

A new medium composed of "cream of rice" infusion, oxgall, Tween 80, and agar is described for the sequential development of germ tubes and chlamydospores by Candida albicans. The procedure used (Dalmau's technique) is an improvement over the fluid substrate procedures previously advocated for germ tube formation. That the same preparation is then used for chlamydospore production is of practical importance for the clinical mycology laboratory.

scholarly journals Farnesol Concentrations Required To Block Germ Tube Formation in Candida albicans in the Presence and Absence of Serum

2005 ◽  
Vol 71 (8) ◽  
pp. 4938-4940 ◽  
Author(s):  
Daniel D. Mosel ◽  
Raluca Dumitru ◽  
Jacob M. Hornby ◽  
Audrey L. Atkin ◽  
Kenneth W. Nickerson
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Tube Formation ◽  
Defined Media ◽  
Presence And Absence ◽  
Germ Tubes

ABSTRACT Concentrations of (E,E)-farnesol needed to inhibit germ tube formation were determined for Candida albicans strains A72 and SC5314 by using six different conditions known to trigger germination. For defined media, 1 to 2 μM farnesol was sufficient. However, with serum at 2 to 20%, up to 250 μM farnesol was required. Farnesol blocked germ tube formation but did not block elongation of existing germ tubes.

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