Effects of culture conditions on the in vitro infection of fibroblasts by Candida albicans

1992 ◽  
Vol 38 (2) ◽  
pp. 135-142 ◽  
Author(s):  
G. J. Merkel

The effects of yeast culture age, carbon source, growth temperature, and germ-tube inducers on adherence to primary fibroblast cultures was studied in conjunction with the determination of adherence-mediated mammalian cell damage by measuring chromium-51 release from fibroblast monolayers. The results indicated that yeast culture age affected adherence only when the yeasts were grown at 37 °C, not after growth at 28 °C. At 37 °C, quantitatively fewer exponential-phase, glucose- or galactose-grown yeasts adhered to fibroblasts than did yeasts that were in lag or stationary phases. The reduced adherence correlated with less chromium-51 release and reduced germ-tube formation. The addition of germ-tube inducers, such as N-acetyl-D-glucosamine or serum, to exponential-phase yeasts caused an increase in germ-tube formation with a concomitant increase in yeast adherence and release of chromium-51 from the monolayers. Exponential-phase galactose-grown yeasts were more responsive to serum-induced germ-tube formation, germ-tube elongation, and fibroblast adherence than were exponential-phase glucose-grown yeasts. In addition, exponential-phase galactose-grown yeasts caused more chromium-51 release from monolayers in the presence of serum than did glucose-grown yeasts. Overall, conditions that enhanced germ-tube formation and elongation resulted in greatest adherence-mediated damage to the monolayers. Key words: Candida albicans, fibroblasts, morphogenesis.

Mycoscience ◽  
2012 ◽  
Vol 53 (1) ◽  
pp. 36-39 ◽  
Author(s):  
María Guadalupe Reyes-García ◽  
Fernando García-Tamayo ◽  
Francisca Hernández-Hernández

2012 ◽  
Vol 57 (1) ◽  
pp. 445-451 ◽  
Author(s):  
Ilka Tiemy Kato ◽  
Renato Araujo Prates ◽  
Caetano Padial Sabino ◽  
Beth Burgwyn Fuchs ◽  
George P. Tegos ◽  
...  

ABSTRACTThe objective of this study was to evaluate whetherCandida albicansexhibits altered pathogenicity characteristics following sublethal antimicrobial photodynamic inactivation (APDI) and if such alterations are maintained in the daughter cells.C. albicanswas exposed to sublethal APDI by using methylene blue (MB) as a photosensitizer (0.05 mM) combined with a GaAlAs diode laser (λ 660 nm, 75 mW/cm2, 9 to 27 J/cm2).In vitro, we evaluated APDI effects onC. albicansgrowth, germ tube formation, sensitivity to oxidative and osmotic stress, cell wall integrity, and fluconazole susceptibility.In vivo, we evaluatedC. albicanspathogenicity with a mouse model of systemic infection. Animal survival was evaluated daily. Sublethal MB-mediated APDI reduced the growth rate and the ability ofC. albicansto form germ tubes compared to untreated cells (P< 0.05). Survival of mice systemically infected withC. albicanspretreated with APDI was significantly increased compared to mice infected with untreated yeast (P< 0.05). APDI increasedC. albicanssensitivity to sodium dodecyl sulfate, caffeine, and hydrogen peroxide. The MIC for fluconazole forC. albicanswas also reduced following sublethal MB-mediated APDI. However, none of those pathogenic parameters was altered in daughter cells ofC. albicanssubmitted to APDI. These data suggest that APDI may inhibit virulence factors and reducein vivopathogenicity ofC. albicans. The absence of alterations in daughter cells indicates that APDI effects are transitory. The MIC reduction for fluconazole following APDI suggests that this antifungal could be combined with APDI to treatC. albicansinfections.


2001 ◽  
Vol 183 (10) ◽  
pp. 3211-3223 ◽  
Author(s):  
Yong-Sun Bahn ◽  
Paula Sundstrom

ABSTRACT In response to a wide variety of environmental stimuli, the opportunistic fungal pathogen Candida albicans exits the budding cycle, producing germ tubes and hyphae concomitant with expression of virulence genes, such as that encoding hyphal wall protein 1 (HWP1). Biochemical studies implicate cyclic AMP (cAMP) increases in promoting bud-hypha transitions, but genetic evidence relating genes that control cAMP levels to bud-hypha transitions has not been reported. Adenylate cyclase-associated proteins (CAPs) of nonpathogenic fungi interact with Ras and adenylate cyclase to increase cAMP levels under specific environmental conditions. To initiate studies on the relationship between cAMP signaling and bud-hypha transitions in C. albicans, we identified, cloned, characterized, and disrupted the C. albicans CAP1 gene. C. albicans strains with inactivated CAP1 budded in conditions that led to germ tube formation in isogenic strains withCAP1. The addition of 10 mM cAMP and dibutyryl cAMP promoted bud-hypha transitions and filamentous growth in thecap1/cap1 mutant in liquid and solid media, respectively, showing clearly that cAMP promotes hypha formation in C. albicans. Increases in cytoplasmic cAMP preceding germ tube emergence in strains having CAP1 were markedly diminished in the budding cap1/cap1 mutant. C. albicans strains with deletions of both alleles ofCAP1 were avirulent in a mouse model of systemic candidiasis. The avirulence of a germ tube-deficientcap1/cap1 mutant coupled with the role of Cap1 in regulating cAMP levels shows that the Cap1-mediated cAMP signaling pathway is required for bud-hypha transitions, filamentous growth, and the pathogenesis of candidiasis.


Mycoses ◽  
2010 ◽  
Vol 54 (6) ◽  
pp. 506-513 ◽  
Author(s):  
Isabela Bueno Rosseti ◽  
Caroline Wagner ◽  
Roselei Fachinetto ◽  
Paulo Taube Junior ◽  
Maricilia Silva Costa

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Thomas Cummins ◽  
Megan Hughes ◽  
Julian Marchesi ◽  
Daniel Morse

Candida albicans is an opportunistic fungal pathogen present in the oral cavities of up to two-thirds of people. Despite typically existing as a commensal microorganism, it has pathogenic potential, particularly in older, immunocompromised individuals. A common Candida-associated infection is denture-associated stomatitis (DS), which presents clinically as areas of erythema on the palatal mucosa, and discomfort for the denture-wearer. In vitro, previous work has shown that the expression of C. albicans virulence factors varies according to its interactions with other oral microorganisms. Mature single- and mixed-species biofilms (with Candida and several strains of common oral bacteria) were grown on poly(methyl methacrylate) (PMMA) coupons, representing dentures. Additionally, to some coupons, individual probiotic strains were added. Total RNA was extracted, reverse transcribed and putative virulence gene expression was determined by RT-qPCR relative to ACT1, a housekeeping gene. Biofilm-infection assays of FADU and TR146 epithelial cell lines were also performed by pre-culturing cells, then adding single- or mixed-species inocula overnight. Quantification of cell damage determined by lactate dehydrogenase assay. Biofilm co-culture with the addition of certain probiotic strains downregulated C. albicans virulence genes in both short-term and long-term mixed-species biofilms. With an increasing aged population that is heavily reliant on the use of antibiotics that can negatively affect the microbiota of patients, there is a requirement to look at the benefits of prophylactics, from both an economic and patient well-being viewpoint. The results show the realistic possibility of using probiotics to prevent or restrict development of Candida-associated oral diseases.


Infectio ◽  
2018 ◽  
Vol 23 (1) ◽  
pp. 16 ◽  
Author(s):  
Mohaddese Mahboubi ◽  
Bahareh Attaran

Satureja khuzistanica Jamzad is known as antiseptic and analgesic agent in folk medicine. The aim of this investigation was to evaluate the anti-candidal activity of S. khuzistanica aerial parts essential oil against clinical isolates of Candida albicans, which were isolated from women with chronic recurrent candidiasis. For this purpose, the chemical composition of hydro-distilled essential oil was determined by GC and GC-MS analysis. Then, the anti-candidal activity of essential oil and its main component (carvacrol) were determined. Carvacrol (94.1%) was the main component of essential oil, followed by β-bisabolene, p-cymene and γ-terpinene. S. khuzistanica essential oil had strong anti-candidal activity against clinical isolates of C. albicans via inhibition of germ tube formation and induction the huge punctures in the cytoplasmic structures. The cell membranes were intact in presence of essential oil or carvacrol. S. khuzistanica essential oil as the main source of carvacrol can be used for treatment of C. albicans related infections.


1994 ◽  
Vol 1 (4) ◽  
pp. 193-197 ◽  
Author(s):  
Acácio Rodrigues ◽  
Cidália Pina Vaz ◽  
A. Freitas Fonseca ◽  
J. Martinez de Oliveira ◽  
Henrique Barros

Objective:This study was planned to clarify the in vitro effect of lidocaine and bupivacaine on germ tube formation byCandida albicansisolates from cases of clinical vaginal candidiasis.Methods:FourteenC. albicansstrains (clinical vaginal isolates) were grown on Sabouraud agar for 24 h at 37℃ and tested as follows: 100 μl of a yeast suspension [105colony forming units (CFU)/ml of phosphate buffered saline (PBS)] was added to 500 μl of fresh human serum with lidocaine or bupivacaine (pure salts) in serial concentrations. The test was run in duplicate. Controls were prepared for each strain. After 4 h of incubation at 37℃, samples were taken from each vial and 200 yeasts were counted in a counting chamber. The pH of each suspension was measured.Results:The results are given as the mean of the 2 readings and are expressed as the percentage of blastoconidia with germ tubes/total blastoconidia.Conclusions:Our experiments show that both lidocaine and bupivacaine have a dose-dependent inhibitory effect, pH-independent, on germ tube formation byC. albicansand that both drugs seem to be promising in the treatment of genital candidiasis due to the combination of anesthetic and antifungal properties.


Microbiology ◽  
1982 ◽  
Vol 128 (10) ◽  
pp. 2319-2326 ◽  
Author(s):  
P. Gopal ◽  
P. A. Sullivan ◽  
M. G. Shepherd

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