scholarly journals Antigenicity of Cell Wall Mannans of Candida albicans NIH A-207 Strain Cells Cultured in Galactose-Added Yeast Nitrogen Base Medium

2005 ◽  
Vol 28 (2) ◽  
pp. 391-393 ◽  
Author(s):  
Yoshio Okawa ◽  
Masayoshi Miyauchi ◽  
Kouji Goto ◽  
Philippe Giummelly
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Base Medium ◽  
Yeast Nitrogen Base Medium ◽  
Cells Cultured

scholarly journals EFFECT OF NIGELLA SATIVA SEED EXTRACT ON THE VIABILITY OF CANDIDA GLABRATA

2019 ◽  
pp. 84-87
Author(s):  
FARAH DIBA ◽  
RATNA FARIDA ◽  
SRI REDJEKI
Keyword(s):  
Candida Glabrata ◽  
Nigella Sativa ◽  
Artificial Saliva ◽  
Positive Control ◽  
Negative Control ◽  
Seed Extract ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Common Opportunistic Infection ◽  
Yeast Nitrogen Base Medium

Objective: Candidiasis is a common opportunistic infection of the oral cavity caused by a yeast-like fungus called Candida. Candida glabrata is thesecond most frequently isolated species from this condition, after Candida albicans. This study aimed to evaluate the effect of Nigella sativa (blackcumin), known to possess antifungal properties, on the viability of C. glabrata.Methods: C. glabrata was added to a 96-microwell plate that was coated with artificial saliva and exposed to various concentrations (6.25%, 12.5%,25%, and 50%) of N. sativa seed extract; amphotericin B (250 mg/mL) was used as the positive control and 200 μL of yeast nitrogen base medium asthe negative control. The viability percentage of C. glabrata was determined by MTT assay.Results: The results showed that the viability values of C. glabrata were lower after exposure to the N. sativa seed extract when compared with thenegative control.Conclusion: The viability of Candida glabrata was decreased with increasing concentrations of the extract.

Dielectrophoretic separation of living cells

1971 ◽  
Vol 17 (7) ◽  
pp. 879-888 ◽  
Author(s):  
B. D. Mason ◽  
P. M. Townsley
Keyword(s):  
Complex Function ◽  
Pulse Height ◽  
Cell Types ◽  
Living Cells ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Pulse Height Analyzer ◽  
Physiological Character ◽  
Cells Cultured

Dielectrophoretic separation studies were undertaken to investigate the possibility of separating cells with varying physiological character. An attempt was made to define the importance of size in the determination of separability. Living cells of Saccharomyces cerevisiae var. ellipsoideus were separated from the same cells killed by heating, using a batch separation. Cells cultured in wort broth were separated from cells grown in yeast nitrogen base – 1% glucose using both batch and continuous separators. Size analyses of separated fractions were performed using a Coulter transducer/multichannel pulse height analyzer. A size differential in cell separability was demonstrated, although it is clear that a complex function of both size and polarizability is instrumental in determining the separation of cell types.

scholarly journals Reversible fluconazole resistance in Candida albicans: a potential in vitro model.

1997 ◽  
Vol 41 (3) ◽  
pp. 535-539 ◽  
Author(s):  
H M Calvet ◽  
M R Yeaman ◽  
S G Filler
Keyword(s):  
Candida Albicans ◽  
Molecular Mechanisms ◽  
Rabbit Model ◽  
Serial Passage ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Fluconazole Resistance ◽  
Karyotypic Analysis

To study the development and potential mechanisms of antifungal resistance in relation to antifungal exposure, reversible fluconazole resistance was examined in vitro. Candida albicans ATCC 36082 blastospores were passed in liquid yeast nitrogen base medium containing either 4, 8, 16, or 128 micrograms of fluconazole per ml, and susceptibility testing was performed after each passage. High-level fluconazole resistance (50% inhibitory concentration, > 256 micrograms/ml) developed in the isolates after serial passage in medium containing 8, 16, or 128 micrograms of fluconazole per ml, but not in isolates passed in 4 micrograms of fluconazole per ml. Reduced susceptibility was noted within four to seven passages, which was equivalent to 14 to 19 days of exposure to the drug. However, all isolates returned to the susceptible phenotype after 8 to 15 passages in medium lacking the drug; thus, fluconazole resistance was reversible in vitro. In vivo, organisms retained the resistant phenotype after a single passage in the rabbit model of infective endocarditis. Restriction digest profiles and karyotypic analysis of the parent strain and selected fluconazole-resistant and -susceptible isolates from each group were identical. Investigations into the molecular mechanisms of this reversible resistance failed to reveal increased accumulation of mRNA for 14 alpha-demethylase, the target enzyme for fluconazole, or for the candidal multidrug transporters CDR1 and BENr. This process of continuous in vitro exposure to antifungal drug may be useful as a model for studying the effects of different antifungal agents and dosing regimens on the development of resistance and for defining the mechanism(s) of reversible resistance.

Delivery of Amphotericin B to Candida albicans by Using Biomachined Lab-on-a-Chip

2017 ◽  
Vol 30 ◽  
pp. 24-30 ◽  
Author(s):  
M. Hanif Nadhif ◽  
Yudan Whulanza ◽  
Jos Istiyanto ◽  
Boy M. Bachtiar
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Continuous Flow ◽  
Drug Testing ◽  
Lab On A Chip ◽  
Yeast Nitrogen Base ◽  
Mold Surface ◽  
Cnc Milling ◽  
Polydimethyl Siloxane ◽  
Nitrogen Base

This paper investigates the ability of biomachined lab-on-a-chip (LoC) to perform drug testing of Amphotericin B to the Candida albicans. The chip is made of polydimethyl siloxane (PDMS). Molds are patterned using CNC milling followed by biomachining. CNC milling process creates channel features on the bottom mold, while biomachining forms rough surface on the channels. After the molds are created, LoC can be manufactured using those molds. Hence, contour surface on LoC’s channels is also realized following the mold surface. Later, Candida albicans is seeded on the LoC’s channels for 24 and 48 hours with the continuous flow of Yeast Nitrogen Base (YNB) Sterile. Then, cell viability is tested using 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium (MTT).The result shows that C. albicans could adhere and grow in the LoC channels. Based on this result, drug testing is conducted in the presence and absence of Amphotericin B (Amp B) under two schemes: without (static) and with (dynamic) the continuous flow of YNB Sterile and Amp B. After 48 hour incubation period, C. albicans biofilm of 28.72 % is shown during dynamic scheme, whereas static scheme had C. albicans biofilm of 99.32 % indicating that the dynamic scheme provides a better efficacy compared to the static scheme.

scholarly journals Counter-Acting Candida albicans-Staphylococcus aureus Mixed Biofilm on Titanium Implants Using Microbial Biosurfactants

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2420
Author(s):  
Erica Tambone ◽  
Alice Marchetti ◽  
Chiara Ceresa ◽  
Federico Piccoli ◽  
Adriano Anesi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Metabolic Activity ◽  
Titanium Implants ◽  
Microbial Colonization ◽  
Total Biomass ◽  
Yeast Nitrogen Base ◽  
Biofilm Inhibition ◽  
Nitrogen Base ◽  
Primary Osteoblasts

This study aimed to grow a fungal-bacterial mixed biofilm on medical-grade titanium and assess the ability of the biosurfactant R89 (R89BS) coating to inhibit biofilm formation. Coated titanium discs (TDs) were obtained by physical absorption of R89BS. Candida albicans-Staphylococcus aureus biofilm on TDs was grown in Yeast Nitrogen Base, supplemented with dextrose and fetal bovine serum, renewing growth medium every 24 h and incubating at 37 °C under agitation. The anti-biofilm activity was evaluated by quantifying total biomass, microbial metabolic activity and microbial viability at 24, 48, and 72 h on coated and uncoated TDs. Scanning electron microscopy was used to evaluate biofilm architecture. R89BS cytotoxicity on human primary osteoblasts was assayed on solutions at concentrations from 0 to 200 μg/mL and using eluates from coated TDs. Mixed biofilm was significantly inhibited by R89BS coating, with similar effects on biofilm biomass, cell metabolic activity and cell viability. A biofilm inhibition >90% was observed at 24 h. A lower but significant inhibition was still present at 48 h of incubation. Viability tests on primary osteoblasts showed no cytotoxicity of coated TDs. R89BS coating was effective in reducing C. albicans-S. aureus mixed biofilm on titanium surfaces and is a promising strategy to prevent dental implants microbial colonization.

Potent Chitin Synthase Inhibitors from Plants

2020 ◽  
Vol 16 (1) ◽  
pp. 58-63
Author(s):  
Amrutha Vijayakumar ◽  
Ajith Madhavan ◽  
Chinchu Bose ◽  
Pandurangan Nanjan ◽  
Sindhu S. Kokkal ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Caenorhabditis Elegans ◽  
Aspergillus Niger ◽  
Small Molecules ◽  
Tip Growth ◽  
Chitin Synthase ◽  
Chitin Synthesis ◽  
Hyphal Tip Growth ◽  
Hyphal Tip

Background: Chitin is the main component of fungal, protozoan and helminth cell wall. They help to maintain the structural and functional characteristics of these organisms. The chitin wall is dynamic and is repaired, rearranged and synthesized as the cells develop. Active synthesis can be noticed during cytokinesis, laying of primary septum, maintenance of lateral cell wall integrity and hyphal tip growth. Chitin synthesis involves coordinated action of two enzymes namely, chitin synthase (that lays new cell wall) and chitinase (that removes the older ones). Since chitin synthase is conserved in different eukaryotic microorganisms that can be a ‘soft target’ for inhibition with small molecules. When chitin synthase is inhibited, it leads to the loss of viability of cells owing to the self- disruption of the cell wall by existing chitinase. Methods: In the described study, small molecules from plant sources were screened for their ability to interfere with hyphal tip growth, by employing Hyphal Tip Burst assay (HTB). Aspergillus niger was used as the model organism. The specific role of these small molecules in interfering with chitin synthesis was established with an in-vitro method. The enzyme required was isolated from Aspergillus niger and its activity was deduced through a novel method involving non-radioactively labelled substrate. The activity of the potential lead molecules were also checked against Candida albicans and Caenorhabditis elegans. The latter was adopted as a surrogate for the pathogenic helminths as it shares similarity with regard to cell wall structure and biochemistry. Moreover, it is widely studied and the methodologies are well established. Results: Out of the 11 compounds and extracts screened, 8 were found to be prospective. They were also found to be effective against Candida albicans and Caenorhabditis elegans. Conclusion: Purified Methyl Ethyl Ketone (MEK) Fraction1 (F1) of Coconut (Cocos nucifera) Shell Extract (COSE) was found to be more effective against Candida albicans with an IC50 value of 3.04 μg/mL and on L4 stage of Caenorhabditis elegans with an IC50 of 77.8 μg/mL.

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